Hello, friends! Main distribution heating network serve to transfer thermal energy of the coolant to consumers for the needs of heating, hot water supply and ventilation. Main heating networks are laid from central heating points (central heating points) or from a heat source (boiler house, combined heat and power plant).
Distribution heating networks consist of such elements as:
1) Non-passable channels
2) Movable and fixed supports
3) Compensators
4) Pipelines and shut-off valves (valves)
5) Thermal cameras
I wrote a separate article about thermal cameras of heating networks. Therefore, I will not consider them in this article.
Impassable channels.
The walls of non-passable channels consist of prefabricated blocks. Reinforced concrete floor slabs are placed on top of the prefabricated blocks. The base of the bottom of an impassable canal is usually done to the side, or towards the basements of residential buildings. But it happens that when the terrain is unfavorable, some of the channels are installed with a slope towards the thermal chambers. The seams of concrete blocks and slabs are sealed and insulated to prevent groundwater and surface water from entering the canal. When backfilling canals, the soil must be thoroughly compacted. Frozen soil cannot be used to fill the canal.
Fixed and movable supports.
The supports of heating network pipelines are divided into fixed (or, as they also say, dead) and movable. In non-passable channels, sliding supports are used. These supports are necessary to transfer the weight of the pipelines and ensure the movement of the pipelines when they are elongated under the influence of the high temperature of the coolant.
To do this, sliding supports, or “sliders” as they are also called, are welded to the pipelines. And they slide on special plates that are embedded in reinforced concrete slabs.
Fixed or dead supports are necessary to divide a long pipeline into separate sections. These sections do not directly depend on each other, and accordingly, at high coolant temperatures, compensators can normally, without visible problems, perceive temperature extensions.
To the fixed supports are presented increased requirements in terms of reliability, because the loads on them are large. At the same time, a violation of the strength and integrity of a dead (fixed) support can lead to an emergency.
Compensators.
Compensators in heating networks are used to absorb the thermal elongation of pipelines when they are heated (1.2 mm per meter for a temperature increase of 100 °C). The main and main task of a compensator in a heating network is to protect pipelines and fittings from “killer” voltages. As a rule, for pipes with a diameter of no more than 200 mm, U-shaped expansion joints. I mostly had to deal with just such compensators in my work. They are the most common. I also had to work with stuffing box expansion joints on large diameter pipelines. But these are pipe diameters of dy 300, 400 mm.
When U-shaped expansion joints are installed, they are pre-stretched by half the thermal elongation of the figure indicated in the project or calculation. Otherwise, the compensating ability of the compensator is reduced by half. Stretching should be done simultaneously on both sides at the joints closest to the dead (fixed) supports.
Pipelines and valves.
For distribution heating networks they use steel pipes. At the joints, the pipelines are connected using electric welding. The valves used in heating networks are steel and cast iron valves. In my work on heating networks, I come across more cast iron valves, they are more common.
Pipe insulation.
I have to work mainly with main heating distribution networks installed back in Soviet time. Of course, in some places the pipelines of heating networks, and accordingly the insulation on them, are changed during overhaul. When I worked in a heat supply organization several years ago, I remember that every year, during the inter-heating period, “ancient” sections of heating network pipelines were replaced. But still, 75-80 percent of heat distribution networks are from Soviet times. The pipelines of such networks are covered with an anti-corrosion compound, thermal insulation and a protective layer (Fig. 4.).
Roll material is usually insulated. Less often - brizol. This material is glued to the pipeline with mastic. Thermal insulation is made of mats mineral wool. The protective layer is asbestos-cement plaster made from a mixture of asbestos and cement in a 1:2 ratio, which is distributed over a wire mesh.
The supports serve to absorb the force from pipelines and transfer them to supporting structures or soil, as well as to ensure the organized joint movement of pipes and insulation during temperature deformations. When constructing heat pipelines, two types of supports are used: movable and fixed.
Movable supports take the weight of the heat pipe and ensure its free movement on building structures during temperature deformations. When the pipeline moves, the movable supports move with it. Movable supports are used for all installation methods, except channelless. When laying without ducts, the heat pipeline is laid on untouched soil or a carefully compacted layer of sand. In this case, movable supports are provided only in places where the route turns and where U-shaped compensators are installed, i.e. in areas where pipelines are laid in channels. The moving supports experience mainly vertical loads from the mass of the pipelines
Based on the principle of free movement, sliding, rolling and suspended supports are distinguished. Sliding supports are used regardless of the direction of horizontal movements of pipelines for all installation methods and for all pipe diameters. These supports are simple in design and reliable in operation.
Roller supports used for pipes with a diameter of 175 mm or more during axial movement of pipes, when laying in tunnels, collectors, on brackets and on free-standing supports. The use of roller bearings in non-passable channels is impractical, since without supervision and lubrication they quickly corrode, stop rotating and actually begin to work as sliding supports. Roller bearings have less friction than sliding bearings, but when poor care the rollers warp and may jam. Therefore, they need to be given the right direction. For this purpose, ring grooves are provided in the rollers, and guide strips are provided on the base plate.
Roller bearings(rarely used, since it is difficult to ensure rotation of the rollers. Roller and roller bearings work reliably in straight sections of the network. At turns in the route, pipelines move not only in the longitudinal, but also in the transverse direction. Therefore, the installation of roller and roller bearings in curved sections is not recommended. in this case use ball bearings. In these supports, the balls move freely along with the shoes along the backing sheet and are kept from rolling out beyond the support by the projections of the support sheet and the shoe.
If, due to local conditions for laying heat pipelines relative to load-bearing structures, sliding and roller supports cannot be installed, suspended supports are used. The non-rigid suspension design allows the support to easily rotate and move along with the pipeline. As a result, as you move away from the fixed support, the angles of rotation of the hangers increase, and the distortion of the pipeline and the stress in the rods under the influence of the vertical load of the pipeline increase accordingly.
Suspended supports, compared to sliding ones, create significantly lower forces along the pipe axis in horizontal sections.
motionless The pipelines are divided into independent sections by supports. With the help of fixed supports, pipes are rigidly fixed at certain points of the route between compensators or sections with natural compensation for temperature deformations, which, in addition to vertical loads, perceive significant horizontal forces directed along the axis of the pipeline and consisting of unbalanced internal pressure forces, resistance forces of free supports and the reaction of compensators . The forces of internal pressure are of greatest importance. Therefore, to facilitate the design of the support, they try to position it on the route in such a way that the internal pressures in the pipeline are balanced and are not transferred to the support. Those supports to which internal pressure reactions are not transmitted are called unloaded fixed supports; the same supports that must absorb unbalanced forces of internal pressure are called unloaded supports.
Exist intermediate and end supports. The intermediate support is subject to forces from both sides, and the end support from one side. Fixed pipe supports are designed to withstand the greatest horizontal load under various operating modes of heat pipelines, including with open and closed valves
Fixed supports are provided on pipelines for all methods of laying heating networks. The magnitude of temperature deformations and stresses in the pipes largely depends on the correct placement of fixed supports along the length of the heating network route. Fixed supports are installed on pipeline branches, in places where shut-off valves and stuffing box compensators are located. On pipelines with U-shaped expansion joints, fixed supports are placed between the expansion joints. When laying ductless heating networks, when self-compensation of pipelines is not used, it is recommended to install fixed supports at the bends of the route.
The distance between the fixed supports is determined based on the given pipeline configuration, thermal elongation of sections and the compensating ability of the installed expansion joints. Fixed fastenings of pipelines are carried out using various structures, which must be strong enough and rigidly hold the pipes, preventing them from moving relative to the supporting structures.
The structures of fixed supports consist of two main elements: load-bearing structures (beams, reinforced concrete slabs), to which the forces from the pipelines are transferred, and the supports themselves, with the help of which the pipes are fixedly secured (welded gussets, clamps). Depending on the installation method and installation location, fixed supports are used: thrust, panel and clamp. Supports with vertical double-sided stops and front ones are used when installing them on frames in chambers and tunnels and when laying pipelines in through, semi-through and non-through channels. Panel supports are used both for channelless installation and for laying heat pipes in non-passable channels when placing the supports outside the chambers.
Panel fixed supports are vertical reinforced concrete panels with holes for the passage of pipes. Axial forces are transmitted to the reinforced concrete shield by rings welded to the pipeline on both sides, reinforced with stiffeners. Until recently, asbestos was laid between the pipe and the concrete. Currently, the use of asbestos packings is not permitted. The load from the pipelines of heating networks is transferred through the panel supports to the bottom and walls of the channel, and in case of channelless installation - to the vertical plane of the ground. Panel supports are made with double symmetrical reinforcement, since the acting forces from the pipes can be directed in opposite directions. At the bottom of the shield, holes are made for the passage of water (if it gets into the channel).
Calculation of fixed supports.
Fixed supports fix the position of the pipeline at certain points and perceive the forces arising at the fixation points under the influence of temperature deformations and internal pressure.
Supports have a very important influence on the operation of the heat pipeline. There are frequent cases of serious accidents due to improper placement of supports, poor design choices or careless installation. It is very important that all supports are loaded, for which purpose it is necessary to verify their placement along the route and their height position during installation. When laying without channels, they usually refuse to install free supports under pipelines in order to avoid uneven settlements, as well as additional bending stresses. In these laying pipes are laid on undisturbed soil or a carefully compacted layer of sand.
The bending stress arising in the pipeline and the deflection boom depend on the span (distance) between the supports.
When calculating bending stresses and deformations, a pipeline lying on free supports is considered as a multi-span beam. In Fig. T.s.19 shows a diagram of the bending moments of a multi-span pipeline.
Let's consider the forces and stresses acting in pipelines.
Let us accept the following notation:
M- power moment, N*m; Q B , Q g - vertical and horizontal force, N; q V , q G- specific load per unit length, vertical and horizontal, H/m;..N - horizontal reaction on the support, N.
The maximum bending moment in a multi-span pipeline occurs at the support. The magnitude of this moment (9.11)
Where q
- specific load per unit length of the pipeline, N/m; 
- span length between supports, m. Specific load q
determined by the formula
(9-12)
Where q B - vertical specific load, taking into account the weight of the pipeline with coolant and thermal insulation; q G - horizontal specific load, taking into account wind force,
(9-13)
Where w
- wind speed, m/s; 
- air density, kg/m3; d And
-
outer diameter of pipeline insulation, m; k
- aerodynamic coefficient equal to an average of 1.4-1.6.
Wind force should be taken into account only in open-laying above-ground heat pipelines.
The bending moment occurring in the middle of the span is
(9.14)
At a distance of 0.2 
from the support the bending moment is zero.
The maximum deflection occurs in the middle of the span.
Pipeline deflection boom 
,
(9.15)
Based on expression (9-11), the span between free supports is determined
(9-16) from where 
,m(9-17)
When choosing the span between supports for real pipeline diagrams, it is assumed that under the most unfavorable operating conditions, for example at the highest temperatures and pressures of the coolant, the total stress from all acting forces in the weakest section (usually a weld) does not exceed the permissible value 
[
].
A preliminary estimate of the distance between supports can be made based on equation (9-17), taking the bending stress 
4 equal to 0.4-0.5 permissible voltage:
Fixed supports perceive the reaction of internal pressure, free supports and
compensator.
The resulting force acting on a fixed support can be represented as
A - coefficient depending on the direction of action of the axial forces of internal pressure on both sides of the support. If the support is unloaded from the internal pressure force, then A=0, otherwise A=1;
R- internal pressure in the pipeline; 
-
internal cross-sectional area of the pipeline; 
-
coefficient of friction on free supports; 
-
difference in lengths of pipeline sections on both sides of the fixed support; 
-
the difference between the frictional forces of axial sliding compensators or the elastic forces of flexible compensators on both sides of the fixed support.
26. Compensation for thermal elongations of pipelines of heat supply systems. Basics of calculation of flexible expansion joints.
In heating networks, gland, U-shaped, and, more recently, bellows (wavy) expansion joints are most widely used. In addition to special compensators, natural angles of rotation of the heating main - self-compensation - are also used for compensation. Compensators must have sufficient compensating capacity 
to perceive the thermal elongation of the pipeline section between the fixed supports, while the maximum stresses in the radial expansion joints should not exceed the permissible ones (usually 110 MPa). It is also necessary to determine the response of the compensator used in calculating loads on fixed supports. Thermal elongation of the design section of the pipeline 
, mm, determined by the formula
, (2.81)
Where 
=1.2· 10ˉ² mm/(m о С),
- calculated temperature difference, determined by the formula 
, (2.82)
Where 
L
Flexible expansion joints Unlike stuffing box valves, they are characterized by lower maintenance costs. They are used for all installation methods and for any coolant parameters. The use of stuffing box compensators is limited to a pressure of no more than 2.5 MPa and a coolant temperature of no higher than 300°C. They are installed when laying underground pipelines with a diameter greater than . 100 mm, for overhead installation on low supports of pipes with a diameter of more than 300 mm, as well as in cramped places where it is impossible to place flexible expansion joints.
Flexible expansion joints are made from bends and straight sections of pipes using electric arc welding. The diameter, wall thickness and steel grade of the expansion joints are the same as the pipelines of the main sections. During installation, flexible expansion joints are placed horizontally; Vertical or inclined placement requires air or drainage devices that make maintenance difficult.
To create maximum compensation capacity, flexible expansion joints are stretched in a cold state before installation and secured in this position with spacers. Size
compensator stretch marks are recorded in a special report. The stretched expansion joints are attached to the heat pipe by welding, after which the spacers are removed. Thanks to pre-stretching, the compensation capacity is almost doubled. To install flexible compensators, compensatory niches are arranged. The niche is a non-passable channel of the same design, the configuration corresponding to the shape of the compensator.
Stuffing box (axial) expansion joints are made from pipes and sheet steel of two types: single-sided and double-sided. The placement of double-sided expansion joints goes well with the installation of fixed supports. Stuffing box compensators are installed strictly along the axis of the pipeline, without distortions. The packing of the stuffing box compensator consists of rings made of asbestos printed cord and heat-resistant rubber. It is advisable to use axial expansion joints when laying pipelines without channels.
The compensating ability of stuffing box expansion joints increases with increasing diameter.
Calculation of flexible compensator.
Thermal elongation of the design section of the pipeline 
, mm, determined by the formula
, (2.81)
Where 
- average coefficient of linear expansion of steel, mm/(m o C), (for standard calculations it can be taken 
=1.2· 10ˉ² mm/(m о С),
- calculated temperature difference, determined by the formula
, (2.82)
Where 
- design temperature coolant, o C;
- calculated outside air temperature for heating design, o C;
L- distance between fixed supports, m.
The compensating capacity of stuffing box expansion joints is reduced by a margin of 50 mm.
Reaction of the stuffing box compensator - frictional force in the stuffing box packing 
determined by the formula, (2.83)
Where 
- working pressure of the coolant, MPa;
- length of the packing layer along the axis of the stuffing box compensator, mm;
- outer diameter of the branch pipe of the stuffing box compensator, m;
- coefficient of friction of the packing on the metal is assumed to be 0.15.
Technical characteristics of bellows expansion joints are given in table. 4.14 - 4.15. Axial reaction of bellows expansion joints 
consists of two terms
(2.84)
Where 
- axial reaction caused by wave deformation, determined by the formula
, (2.85)
where l- temperature elongation of the pipeline section, m;
- wave rigidity, N/m, taken according to the compensator passport; n- number of waves (lenses). 
- axial reaction from internal pressure, determined by the formula
, (2.86)
Where 
- coefficient depending on the geometric dimensions and thickness of the wave wall, equal on average to 0.5 - 0.6;
D And d are the outer and inner diameters of the waves, respectively, m;
- excess coolant pressure, Pa.
When calculating self-compensation, the main task is to determine the maximum voltage at the base of the short arm of the route rotation angle, which is determined for rotation angles of 90° 
formula 
; (2.87)
for angles greater than 90°, i.e. 90+
, according to the formula 
(2.88)
where l- lengthening of the short arm, m; l- short arm length, m; E- modulus of longitudinal elasticity, equal on average for steel to 2·10 5 MPa; d- outer diameter of the pipe, m;
- the ratio of the length of the long arm to the length of the short one.
On free-standing masts and supports (Fig. 4.1);
Rice. 4.1. Laying pipelines on free-standing masts
Fig. 4.2 - on overpasses with a continuous span in the form of trusses or beams (Fig. 4.2);
Rice. 4.2. Overpass with a span for laying pipelines
Fig. 4.3 - on rods attached to the tops of the masts (cable-stayed structure, Fig. 4.3);
Rice. 4.3. Laying pipes with suspension on rods (cable-stayed design)
On brackets.
Gaskets of the first type are the most rational for pipelines with a diameter of 500 mm or more. Pipelines of larger diameter can be used as load-bearing structures for laying or suspending several small-diameter pipelines that require more frequent installation of supports.
It is advisable to use gaskets on overpasses with continuous flooring for passage only when large quantities pipes (at least 5 - 6 pieces), as well as, if necessary, regular supervision of them. In terms of construction cost, a walk-through overpass is the most expensive and requires the greatest metal consumption, since trusses or beam decking are usually made of rolled steel.
The third type of installation with a suspended (cable-stayed) span structure is more economical, as it allows you to significantly increase the distance between masts and thereby reduce consumption building materials. The simplest structural forms of suspended gaskets are obtained with pipelines of equal or similar diameters.
When laying large and small diameter pipelines together, a slightly modified cable-stayed structure is used with purlins made of channels suspended on rods. Purlins allow installation of pipeline supports between masts. However, the possibility of laying pipelines on overpasses and suspended on rods in urban environments is limited and is applicable only in industrial areas. Most Applications received the laying of water pipelines on free-standing masts and supports or on brackets. Masts and supports are usually made of reinforced concrete. Metal masts are used in exceptional cases for small volumes of work and reconstruction of existing heating networks.
Masts according to their purpose are divided into the following types:
- for movable supports of pipelines (so-called intermediate);
- for fixed pipeline supports (anchors), as well as those installed at the beginning and end of a route section;
- installed at the turns of the route;
- serving to support pipeline expansion joints.
Depending on the number, diameter and purpose of the pipelines being laid, the masts are made in three different structural forms: single-post, two-post and four-post spatial design.
When designing air spacers, one should strive to increase the distances between masts as much as possible.
However, for unhindered water flow when pipelines are turned off, the maximum deflection should not exceed
f = 0,25∙i∙l,Where f- pipeline deflection in the middle of the span, mm; i - slope of the pipeline axis; l- distance between supports, mm.
Precast concrete mast structures are usually assembled from the following elements: posts (columns), crossbars and foundations. The dimensions of the prefabricated parts are determined by the number and diameter of the pipelines being laid.
When laying from one to three pipelines, depending on the diameter, single-post free-standing masts with consoles are used; they are also suitable for cable-stayed suspension of pipes on rods; then a top device is provided for attaching the rods.
Masts of a solid rectangular section are permissible if the maximum dimensions cross section do not exceed 600 x 400 mm. For large sizes, to facilitate the design, it is recommended to provide cutouts along the neutral axis or use centrifuged ones as racks. reinforced concrete pipes factory made.
For multi-pipe installations, intermediate support masts are most often designed as a two-post structure, single-tier or two-tier.
Prefabricated two-post masts consist of the following elements: two posts with one or two consoles, one or two crossbars and two glass-type foundations.
The masts on which the pipelines are fixedly fixed are subject to load from horizontally directed forces transmitted by the pipelines, which are laid at a height of 5 - 6 m from the ground surface. To increase stability, such masts are designed in the form of a four-post spatial structure, which consists of four posts and four or eight crossbars (with a two-tier arrangement of pipelines). The masts are installed on four separate glass-type foundations.
When laying large-diameter pipelines above ground, the load-bearing capacity of the pipes is used, and therefore no span structure is required between the masts. Suspension of large-diameter pipelines on rods should not be used, since such a design will practically not work.
Fig.4.4As an example, the laying of pipelines on reinforced concrete masts is shown (Fig. 4.4).
1 - column; 2 - crossbar; 3 - communication; 4 - foundation; 5 - connecting joint; 6 - concrete preparation.
Two pipelines (direct and return) with a diameter of 1200 mm are laid on roller supports on reinforced concrete masts installed every 20 m. The height of the masts from the ground surface is 5.5 - 6 m. Prefabricated reinforced concrete masts consist of two foundations connected to each other by a monolithic joint, two columns of rectangular section 400 x 600 mm and a crossbar. The columns are connected to each other by metal diagonal ties made of angle steel. The connection of the ties with the columns is made with gussets welded to the embedded parts, which are embedded in the columns. The crossbar, which serves as a support for pipelines, is made in the form of a rectangular beam with a cross-section of 600 x 370 mm and is attached to the columns by welding embedded steel sheets.
The mast is designed for the weight of the pipe span, horizontal axial and lateral forces arising from the friction of pipelines on the roller supports, as well as for wind load.
Rice. 4.5. Fixed support:
1 - column; 2 - transverse crossbar; 3 - longitudinal crossbar; 4 - cross connection; 5 - longitudinal connection; 6 - foundation
Fig. 4.5 The fixed support (Fig. 4.5), designed for a horizontal force from two pipes of 300 kN, is made of prefabricated reinforced concrete parts: four columns, two longitudinal crossbars, one transverse support crossbar and four foundations connected in pairs.
In the longitudinal and transverse directions, the columns are connected by metal diagonal braces made of angle steel. The pipelines are secured to the supports with clamps covering the pipes and gussets at the bottom of the pipes, which rest against a metal frame made of channels. This frame is attached to reinforced concrete crossbars welding to embedded parts.
Laying pipelines on low supports has found wide application in the construction of heating networks in unplanned areas of new urban areas. It is more expedient to cross rough or swampy terrain, as well as small rivers, in this way using the bearing capacity of pipes.
However, when designing heating networks with the laying of pipelines on low supports, it is necessary to take into account the period of planned development of the territory occupied by the route for urban development. If in 10 - 15 years it will be necessary to enclose pipelines in underground channels or reconstruct the heating network, then the use of air laying is inappropriate. To justify the use of the method of laying pipelines on low supports, technical and economic calculations must be performed.
When laying large diameter pipelines above ground (800-1400 mm), it is advisable to lay them on separate masts and supports using special prefabricated reinforced concrete structures factory-made, meeting the specific hydrogeological conditions of the heating main route.
Design experience shows the cost-effectiveness of using pile foundations for the foundations of both anchor and intermediate masts and low supports.
Aboveground heating mains of large diameter (1200-1400 mm) of considerable length (5 - 10 km) are built according to individual designs using high and low supports on a pile foundation.
We have experience in constructing heating mains with pipe diameters D= 1000 mm from the thermal power plant using rack piles in the wetlands of the route, where rocky soils lie at a depth of 4-6 m.
Calculation of supports on a pile foundation for the combined action of vertical and horizontal loads is carried out in accordance with SNiP II-17-77 “Pile foundations”.
When designing low and high supports for laying pipelines, the designs of standardized prefabricated reinforced concrete free-standing supports designed for process pipelines can be used [3].
The design of low supports of the type of “swinging” foundations, consisting of a reinforced concrete vertical shield installed on a flat foundation slab, was developed by AtomTEP. These supports can be used in various soil conditions (with the exception of heavily watered and subsiding soils).
One of the most common types of aerial laying of pipelines is the installation of the latter on brackets fixed in the walls of buildings. The use of this method can be recommended when laying heating networks on the territory of industrial enterprises.
When designing pipelines located on the outer or inner surface of walls, you should choose such a placement of pipes so that they do not cover window openings, did not interfere with the placement of other pipelines, equipment, etc. The most important thing is to ensure that the brackets are securely fastened to the walls existing buildings. Designing the installation of pipelines along the walls of existing buildings should include an examination of the walls in situ and a study of the designs for which they were built. In case of significant loads transmitted by pipelines to the brackets, it is necessary to calculate the overall stability of the building structures.
The pipelines are laid on brackets with welded sliding support bodies. The use of roller movable bearings for external laying of pipelines is not recommended due to the difficulty of periodically lubricating and cleaning them during operation (without which they will work as sliding ones).
In case of insufficient reliability of the walls of the building, constructive measures must be taken to disperse the forces transmitted by the brackets by reducing spans, installing struts, vertical racks etc. Brackets installed in places where fixed pipeline supports are installed must be designed to withstand the forces acting on them. Usually they require additional fastening by installing struts in horizontal and vertical planes. In Fig. 4.6 is given standard design brackets for laying one or two pipelines with a diameter of 50 to 300 mm.
Fig.4.6
a - for one pipe; b - for two pipes
Supports in heating networks they are installed to absorb the forces arising in heat pipelines and transfer them to supporting structures or soil. Depending on their purpose they are divided into movable(free) and motionless(dead).
Movable the supports are designed to bear the weight loads of the heat pipe and ensure its free movement during temperature deformations. They are installed for all types of laying, except for ductless, when heat pipes are laid on a compacted layer of sand, which ensures a more uniform transfer of weight loads to the ground.
The heat pipeline lying on movable supports, under the influence of weight loads (the weight of the pipeline with the coolant, the insulating structure and equipment, and sometimes wind load), bends and bending stresses arise in it, the values of which depend on the distance (span) between the supports. In this regard, the main task of the calculation is to determine the maximum possible span between supports, at which bending stresses do not exceed permissible values, as well as the amount of deflection of the heat pipe between the supports.
Currently, the following main types of movable supports are used: sliding, roller (ball) (Fig. 29.1) and suspended with rigid and spring suspensions.
Rice. 29.1. Movable supports
A- sliding with a welded shoe; b- skating rink; V- sliding with a semi-cylinder glued; 1 - shoe; 2 - support cushion; 3 - support half-cylinder
In sliding supports, a shoe (support body), welded to the pipeline, slides along a metal lining embedded in a supporting concrete or reinforced concrete pad. In Roller (and ball) bearings, the shoe rotates and moves the roller (or balls) along a support sheet, which is provided with guide bars and recesses to prevent distortions, jamming and roller exit. When the roller (balls) rotate, there is no sliding of the surfaces, as a result of which the value of the horizontal reaction decreases. The places where the shoe is welded to the pipeline are dangerous in terms of corrosion, so designs of free supports with clamps should be considered more promising. and glued shoes, which are installed without damaging the thermal insulation. In Fig. 29.1, in The design of a sliding support with a glued support shoe (half-cylinder) developed by NIIMosstroy is shown. Sliding bearings are the simplest and are widely used.
Suspended supports with rigid suspensions are used for above-ground laying of heat pipelines in areas that are not sensitive to distortions: with natural compensation, U-shaped compensators.
Spring supports compensate for distortions, as a result of which they are used in areas where distortions are unacceptable, for example, with stuffing box compensators.
Fixed supports are designed to secure the pipeline at individual points, divide it into sections independent of temperature deformations and to absorb the forces arising in these sections, which eliminates the possibility of a consistent increase in forces and their transfer to equipment and fittings. These supports are usually made of steel or reinforced concrete.
Steel fixed supports(Fig. 29.2, a and b) are usually a steel supporting structure (beam or channel), located between stops welded to the pipe. The supporting structure is clamped into the building structures of the chambers, welded to masts, overpasses, etc.
Reinforced concrete fixed supports usually made in the form of a shield (Fig. 29.2,c), installed during channelless laying on a foundation (concrete stone) or pinched at the base and overlap of channels and chambers. On both sides of the shield support, support rings (flanges with gussets) are welded to the pipeline, through which forces are transmitted. At the same time, shield supports do not require powerful foundations, since the forces are transferred to them centrally. When making shield supports in channels, holes are made in them to allow water and air to pass through.
Figure 29.2 Fixed supports
a - with a steel supporting structure b - clamp c - panel board
When developing an installation diagram for heating networks, fixed supports are installed at the outlet of the heat source, at the inlet and outlet of central heating stations, pumping substations, etc. to relieve stress on equipment and fittings; in places of branches to eliminate the mutual influence of sections running in perpendicular directions; at road turns to eliminate the influence of bending and torque moments that arise during natural compensation. As a result of the specified arrangement of fixed supports, the route of heating networks is divided into straight sections having different lengths and diameters of pipelines. For each of these sections, the type and required number of compensators are selected, depending on which the number of intermediate fixed supports is determined (one less than compensators).
The maximum distance between fixed supports with axial expansion joints depends on their compensating capacity. For bent expansion joints, which can be manufactured to compensate for any deformations, they are based on the condition of maintaining the straightness of the sections and permissible bending stresses in the dangerous sections of the expansion joint. Depending on the accepted length of the section, at the ends of which fixed supports are installed, its elongation is determined, and then, by calculation or using nomograms, the overall dimensions of the bent compensators and the horizontal reaction.
Thermal compensators.
Compensation devices in heating networks they serve to eliminate (or significantly reduce) the forces that arise during thermal elongation of pipes. As a result, stresses in the pipe walls and forces acting on equipment and supporting structures are reduced.
Elongation of pipes as a result thermal expansion metal is determined by the formula
Where A- coefficient of linear expansion, 1/°С; l- pipe length, m; t- operating wall temperature, 0 C; t m - installation temperature, 0 C.
To compensate for the elongation of pipes, special devices are used - compensators, and they also use the flexibility of pipes at turns in the route of heating networks (natural compensation).
According to the principle of operation, compensators are divided into axial and radial. Axial compensators are installed on straight sections of the heat pipeline, since they are designed to compensate for forces arising only as a result of axial elongations. Radial compensators are installed on heating networks of any configuration, as they compensate for both axial and radial forces. Natural compensation does not require the installation of special devices, so it must be used first.
They are used in heating networks axial expansion joints two types: omental and lens. In stuffing box compensators (Fig. 29.3), thermal deformations of the pipes lead to the movement of the glass 1 inside the housing 5, between which the stuffing box packing 3 is placed for sealing. The packing is clamped between the thrust ring 4 and the ground bushing 2 using bolts 6.
Figure 19.3 Stuffing box expansion joints
a - one-sided; b - double-sided: 1 - glass, 2 - ground box, 3 - stuffing box,
4 - thrust ring, 5 - body, 6 - tightening bolts
An asbestos printed cord or heat-resistant rubber is used as an omental packing. During operation, the packing wears out and loses its elasticity, so periodic tightening (clamping) and replacement are required. To make it possible to carry out these repairs, stuffing box compensators are placed in chambers.
The connection of expansion joints to pipelines is carried out by welding. During installation, it is necessary to leave a gap between the collar of the cup and the thrust ring of the body, eliminating the possibility of tensile forces in the pipelines if the temperature drops below the installation temperature, and also carefully align the center line to avoid distortions and jamming of the cup in the body.
Stuffing box expansion joints are made one-sided and two-sided (see Fig. 19.3, a and b). Double-sided ones are usually used to reduce the number of chambers, since a fixed support is installed in the middle of them, separating sections of pipes, the extensions of which are compensated by each side of the compensator.
The main advantages of stuffing box expansion joints are their small dimensions (compactness) and low hydraulic resistance, as a result of which they are widely used in heating networks, especially for underground installation. In this case, they are installed at d y =100 mm or more, for overhead installation - at d y =300 mm or more.
In lens compensators (Fig. 19.4), with thermal elongation of pipes, special elastic lenses (waves) are compressed. This ensures complete tightness in the system and does not require maintenance of expansion joints.
Lenses are made from sheet steel or stamped half-lenses with a wall thickness of 2.5 to 4 mm using gas welding. To reduce hydraulic resistance, a smooth pipe (jacket) is inserted inside the compensator along the waves.
Lens compensators have a relatively small compensating capacity and a large axial reaction. In this regard, to compensate for temperature deformations of heating network pipelines, a large number of waves are installed or they are pre-stretched. They are usually used up to pressures of approximately 0.5 MPa, since at high pressures swelling of waves is possible, and increasing the rigidity of waves by increasing the thickness of the walls leads to a decrease in their compensating ability and an increase in the axial reaction.
Cassock. 19.4. Lens three-wave compensator
Natural compensation temperature deformations occur as a result of bending of pipelines. Bent sections (turns) increase the flexibility of the pipeline and increase its compensating ability.
With natural compensation at turns in the route, temperature deformations of pipelines lead to lateral displacements of sections (Fig. 19.5). The amount of displacement depends on the location of the fixed supports: the greater the length of the section, the greater its elongation. This requires an increase in the width of the channels and complicates the operation of the movable supports, and also does not make it possible to use modern channelless laying at the turns of the route. The maximum bending stresses occur at the fixed support of a short section, since it is displaced by a large amount.
Rice. 19.5 Scheme of operation of the L-shaped section of the heat pipeline
A– with equal shoulder lengths; b– at different shoulder lengths
TO radial expansion joints, used in heating networks, include flexible And wavy hinged type. In flexible expansion joints, thermal deformations of pipelines are eliminated by bending and torsion of specially bent or welded sections of pipes of various configurations: U- and S-shaped, lyre-shaped, omega-shaped, etc. U-shaped expansion joints are most widespread in practice due to ease of manufacture (Fig. 19.6 ,A). Their compensating ability is determined by the sum of deformations along the axis of each pipeline section ∆ l= ∆l/2+∆l/2. In this case, the maximum bending stresses occur in the section furthest from the pipeline axis - the back of the compensator. The latter, bending, shifts by an amount y, by which it is necessary to increase the dimensions of the compensatory niche.
Rice. 19.6 Scheme of operation of the U-shaped compensator
A– without preliminary stretching; b– with pre-stretching
To increase the compensating capacity of the compensator or reduce the amount of displacement, it is installed with preliminary (assembly) stretching (Fig. 19.6, b). In this case, the back of the compensator when not in use is bent inward and experiences bending stresses. When the pipes are lengthened, the compensator first comes to a stress-free state, and then the back bends outward and bending stresses of the opposite sign arise in it. If in extreme positions, i.e. during pre-stretching and in working condition, the maximum permissible stresses, then the compensating capacity of the compensator doubles compared to a compensator without pre-stretching. In the case of compensation for the same temperature deformations in the compensator with pre-stretching, the backrest will not shift outward and, consequently, the dimensions of the compensatory niche will decrease. The operation of flexible compensators of other configurations occurs in approximately the same way.
Pendants
Pipeline hangers (Fig. 19.7) are carried out using rods 3, connected directly to pipes 4 (Fig. 19.7, A) or with a traverse 7 , to which on clamps 6 pipe is suspended (Fig. 19.7, b), and also through spring blocks 8 (Fig. 19.7, V). Swivel joints 2 ensure the movement of pipelines. The guide cups 9 of the spring blocks, welded to the support plates 10, make it possible to eliminate the transverse deflection of the springs. The suspension tension is ensured using nuts.
Rice. 19.7 Pendants:
A– traction; b– clamp; V– spring; 1 – support beam; 2, 5 – hinges; 3 – traction;
4 - pipe; 6 – clamp; 7 – traverse; 8 – spring suspension; 9 – glasses; 10 – plates
3.4 Methods for insulating heating networks.
Mastic insulation
Mastic insulation is used only when repairing heating networks laid either indoors or in passage channels.
Mastic insulation is applied in layers of 10-15 mm to the hot pipeline as the previous layers dry. Mastic insulation cannot be performed using industrial methods. Therefore, the specified insulating structure is not applicable for new pipelines.
Sovelite, asbestos and vulcanite are used for mastic insulation. The thickness of the thermal insulation layer is determined on the basis of technical and economic calculations or according to current standards.
The temperature on the surface of the insulating structure of pipelines in passage channels and chambers should not exceed 60° C.
The durability of the thermal insulation structure depends on the operating mode of the heat pipes.
Block insulation
Prefabricated block insulation from pre-formed products (bricks, blocks, peat slabs, etc.) is installed on hot and cold surfaces. Products with bandaged seams in rows are laid on a mastic base made of asbozurite, the thermal conductivity coefficient of which is close to the coefficient of the insulation itself; The underlay has minimal shrinkage and good mechanical strength. Peat products (peat slabs) and corks are laid on bitumen or iditol glue.
Thermal insulation products are secured to flat and curved surfaces with steel studs, pre-welded in a checkerboard pattern at intervals of 250 mm. If installation of studs is not possible, the products are fixed as mastic insulation. On vertical surfaces more than 4 m high, unloading support belts made of strip steel are installed.
During the installation process, the products are adjusted to each other, marked and holes for the studs are drilled. The mounted elements are secured with studs or wire twists.
With multi-layer insulation, each subsequent layer is laid after leveling and securing the previous one, overlapping the longitudinal and transverse seams. The last layer, secured by a frame or metal mesh, level with mastic under the lath and then apply plaster 10 mm thick. Pasting and painting are carried out after the plaster has completely dried.
The advantages of prefabricated block insulation are industrial, standard and prefabricated, high mechanical strength, the possibility of lining hot and cold surfaces. Disadvantages: multiple seams and complexity of installation.
Backfill insulation
On horizontal and vertical surfaces building structures Loose fill insulation is used.
When installing thermal insulation on horizontal surfaces (attic roofs, ceilings above the basement), the insulating material is predominantly expanded clay or perlite.
On vertical surfaces, fill-in insulation is made from glass or mineral wool, diatomaceous earth chips, perlite sand, etc. To do this, the parallel insulated surface is fenced with bricks, blocks or nets, and insulating material is poured (or stuffed) into the resulting space. When using mesh fencing, the mesh is attached to studs pre-installed in a checkerboard pattern with a height corresponding to the specified insulation thickness (with an allowance of 30...35 mm). A metal woven mesh with a cell of 15x15 mm is stretched over them. Bulk material is poured into the resulting space layer by layer from bottom to top with light compaction.
After backfilling is completed, the entire surface of the mesh is covered with a protective layer of plaster.
Loose-fill insulation is quite effective and simple to install. However, it is not resistant to vibration and is characterized by low mechanical strength.
Cast insulation
As insulating material Foam concrete is mainly used, which is prepared by mixing cement mortar with foam mass in a special mixer. The thermal insulation layer is laid using two methods: conventional methods of concreting the space between the formwork and the insulated surface or shotcrete.
With the first method Formwork is placed parallel to the vertical insulated surface. The heat-insulating composition is placed in rows into the resulting space, leveling with a wooden trowel. The laid layer is moistened and covered with mats or matting to ensure normal hardening conditions for foam concrete.
Shotcrete method cast insulation is applied over mesh reinforcement made of 3-5 mm wire with cells of 100-100 mm. The applied shotcrete layer fits tightly to the insulated surface and has no cracks, cavities or other defects. Shotcrete is carried out at a temperature not lower than 10°C.
Cast thermal insulation is characterized by simplicity of design, solidity, and high mechanical strength. The disadvantages of cast thermal insulation are the long duration of the device and the impossibility of working at low temperatures.
Wrap insulation
Wrapping structures are made of tufted mats or soft boards on a synthetic bond, which are sewn together with transverse and longitudinal seams. The covering layer is attached in the same way as in suspended insulation. Wrapping structures in the form of thermal insulating strands made of mineral or glass wool, after applying them to the surface, are also covered with a protective layer. Insulate joints, fittings, fittings. Mastic insulation is also used for thermal insulation at the installation site of fittings and equipment. Powdered materials are used: asbestos, asbozurt, sovelit. The mixture mixed with water is applied to the preheated insulated surface manually. Mastic insulation is rarely used, as a rule, during repair work.
3.5 Pipelines.
In a boiler unit, elements under pressure from the working substance (water, steam) are connected to each other, as well as to other equipment, by a pipeline system. Pipelines consist of pipes and connecting parts to them, fittings used to control and regulate boiler units and auxiliary equipment - pipe supports and hanging fastenings, thermal insulation, compensators and bends designed to accommodate thermal expansion of pipelines.
Pipelines are divided according to their purpose into main and auxiliary. TO main pipelines include supply pipelines and steam pipelines for saturated and superheated steam, auxiliary- drainage, purge, blow-off pipelines and pipelines for sampling water, steam, etc.
According to parameters (pressure and temperature), pipelines are divided into four categories (Table 19.1).
The following basic requirements are imposed on pipelines and fittings:
– all steam pipelines for pressures above 0.07 MPa and water pipelines operating under pressure at temperatures above 115 C, regardless of the degree of importance, must comply with the rules of the Gosgortekhnadzor of Russia;
– reliable operation of the pipelines, safe for operating personnel, must be ensured. It should be borne in mind that fittings and flange connections are the least reliable parts, especially when high temperatures and pressure, therefore, to increase reliability, as well as to reduce the cost of equipment, their use should be reduced;
– the pipeline system must be simple, clear and provide the possibility of easy and safe switching during operation;
– the loss of pressure of the working fluid and the loss of heat to the environment should be as minimal as possible. Taking this into account, it is necessary to select the diameter of the pipeline, the design and size of the fittings, the quality and type of insulation.
Supply pipelines
The supply pipeline layout must ensure complete reliability of water supply to the boilers under normal and emergency conditions. To supply steam boilers with a steam capacity of up to 40 t/h, one supply pipeline is allowed; For boilers with higher productivity, two pipelines are needed so that if one of them fails, the second can be used.
The supply pipelines are installed so that from any pump in the boiler room it is possible to supply water to any boiler unit via one or the other supply line.
The supply pipelines must have shut-off devices in front of and behind the pump, and directly in front of the boiler - check valve and valve. All newly manufactured steam boilers with a steam output of 2 t/h and above, as well as boilers in operation with a steam output of 20 t/h and above, must be equipped with automatic power regulators controlled from the boiler operator’s workplace.
In Fig. Figure 19.8 shows a diagram of supply pipelines with double lines. Water from the tank 12 feed water centrifugal pump 11 with an electric drive is supplied to the supply lines (pipelines 14 ). Shut-off devices are installed on the suction and main lines of the pumps. There are two water outlets from the main line to each of the boilers. A control valve is installed on the bends 3 , check valve 1 and shut-off valve 2 . The check valve allows water only into the boiler 4 . When water moves in the opposite direction, the check valve closes, which prevents water from leaving the boiler. The shut-off valve is used to disconnect the supply line from the boiler when repairing the line or check valve.
Both highways are usually in operation. One of them, if necessary, can be turned off without disturbing the normal power supply of the boilers.
Rice. 19.8. Diagram of supply pipelines with double lines:
1 - check valve; 2, 3 - shut-off and control valves; 4 - boilers; 5 - air vent; 6 - thermometer; 7 - economizer; 8 - pressure gauge; 9 - safety valve;
10 - flow meter; 11, 13 - centrifugal and steam pumps; 12 - feed water tank;
14 - supply pipelines
Drainage pipelines
Drainage pipelines are designed to remove condensate from steam lines. Condensate accumulates in steam lines as a result of steam cooling. The greatest cooling of steam occurs when the cold steam line is warmed up and turned on. At this time, it is necessary to ensure enhanced removal of condensate from it. Otherwise, it may accumulate in large quantities in the pipeline. When the speed of steam movement in the steam line is approximately 20...40 m/s for saturated steam and 60...80 m/s for superheated steam, the water particles in it, moving along with the steam at high speed, cannot do so quickly change their direction of movement, like steam (due to the large difference in their densities), so they tend to move in a straight line by inertia. But since the steam pipeline has a number of elbows and curves, gates and valves, when water encounters these obstacles, it hits them, creating hydraulic shocks.
Depending on the water content of the steam, hydraulic shocks can be so strong that they cause destruction of the steam line. The accumulation of water in the main steam pipelines is especially dangerous, as it can be thrown into steam turbine and lead to an accident.
To avoid such phenomena, steam pipelines are equipped with appropriate drainage devices, which are divided into temporary (start-up) and permanent (continuously operating). Temporary drainage device serves to remove condensate from the steam line during its heating and purging. Such a drainage device is made in the form of an independent pipeline, which is turned off during normal operation.
A permanent drainage device is designed to continuously remove condensate from a steam line under steam pressure, which is carried out using automatic condensate drains (condensation traps).
Pipeline drainage is performed at the lowest points of each section of the steam pipeline that is disconnected by valves and at the lowest points of steam pipeline bends. Valves (vents) must be installed at the highest points of steam pipelines to remove air from the pipeline.
For better condensate removal, horizontal sections of the pipeline must have a slope of at least 0.004 in the direction of steam movement.
For purging during warming up, the steam line is equipped with a fitting with a valve, and at a pressure above 2.2 MPa - with a fitting and two valves - shut-off and adjustment (drainage).
For the saturated steam line and dead-end sections of the superheated steam line, continuous condensate removal must be provided by means of automatic condensation traps.
In Fig. Figure 19.9 shows a condensation pot with an open float. The principle of its operation is based on the following. The condensate entering the pot, as it accumulates in the open float 5, leads to its flooding. A needle valve 1 connected to the float by a spindle 6 opens a hole in the lid of the pot, and water from the float through the guide tube 7 is forced out through this hole, after which the lightweight float floats up and the needle valve closes the hole. During operation, make sure that the valve of the automatic condensate drain does not allow steam to pass through, as this leads to large heat losses.
The normal operation of the condensation trap is checked by periodically opening valve 3 to drain condensate. In addition, the operation of the condensate drain can be assessed by ear: during normal operation, a characteristic noise is heard inside the pot, and if the valve hole is blocked by scale or scale, or if the moving parts are jammed, the noise level in it decreases or completely stops. The normal operation of the pot can also be determined by the heating of the drainage pipe: if the pipe is hot, then the pot is working normally.
Rice. 19.9. Condensation pot with open float: 1 - needle valve; 2 - check valve (often missing); 3 - valve (condensate drain valve); 4 - pot body; 5 - open float; 6 - float spindle; 7 - guide tube
Lecture No. 16 (2 hours)
Subject: "Renewable and secondary energy resources in agriculture"
1 Lecture questions:
1.1 General information.
1.2 Solar power supply system.
1.3 Geothermal resources and their types.
1.4 Bioenergy plants.
1.5 Use of secondary energy resources.
2 Literature.
2.1 Basic
2.1.1 Amerkhanov R.A., Bessarab A.S., Dragonov B.Kh., Rudobashta S.P., Shmshko G.G. Thermal power plants and systems Agriculture/ Ed. B.H. Draganova. – M.: Kolos-Press, 2002. – 424 p.: ill. – (Textbooks and teaching aids for students of higher educational institutions).
2.1.2 Fokin V.M. Heat generating installations of heat supply systems. M.: Publishing House Mashinostroenie-1, 2006. 240 p.
2.2 Additional
2.2.1 Sokolov B.A. Boiler installations and their operation. – 2nd ed., rev. M.: Publishing center "Academy", 2007. - 423 p.
2.2.2 Belousov V.N., Smorodin S.N., Smirnova O.S. Fuel and combustion theory. Part I Fuel: tutorial/ SPbGTURP. – St. Petersburg, 2011. -84 p.: ill. 15.
2.2.3. Esterkin, R.I. Industrial steam generating plants. – L.: Energy. Leningr. department, 1980. – 400 p.
3.1 General information.
Energy sources: a) non-renewable
Non-renewable energy sources are oil, gas, coal, shale.
Recoverable reserves of fossil fuels in the world are estimated as follows (billion tons):
Coal -4850
Oil - 1140
At the level of world production in the nineties (billion tons of fuel equivalent), respectively 3.1-4.5-2.6, totaling 10.3 billion tons of fuel equivalent, coal reserves will last for 1500 years, oil for 250 years and gas for 120 years. years.
The prospect of leaving descendants without energy supplies. Especially considering the steady trend of rising oil and gas prices. And the further, the faster.
The main advantage of renewable energy sources is their inexhaustibility and environmental friendliness. Their use does not change the energy balance of the planet.
A widespread transition to renewable energy sources does not occur only because industry, machinery, equipment and the way of life of people on Earth are focused on fossil fuels, and some types of renewable energy sources are intermittent and have low energy density.
Until recently, the high cost of renewable sources was also mentioned.
3.2 Solar power supply system.
Rice. 3 applications 16. Fixed panel supports for pipelines D n 108-1420 mm type III with protection against electrocorrosion: a) ordinary;
b) reinforced
Rice. 4 applications 16. Fixed free-standing pipe support
D at 80-200 mm. (basement).
Movable supports for heating pipelines.
Rice. 5. Movable supports:
a - sliding movable support; b – skating rink; c – roller;
1 – paw; 2 – base plate; 3 – base; 4 – rib; 5 – lateral rib;
6 – pillow; 7 – mounting position of the support; 8 – skating rink; 9 – roller;
10 – bracket; 11 – holes.
Rice. 6. Hanging support:
12 – bracket; 13 – hanging bolt; 14 – traction.
Appendix 17. Friction coefficients in moving supports
Appendix 18. Laying pipelines for heating networks.
|
|
Table 1 of Appendix 18. Structural dimensions of ductless installation of heating networks in reinforced foam concrete insulation in dry soils (without drainage).
| D y, mm | D n, (with a covering layer) | ||||||||||||||
| D P | D o | A | B | IN | l | k | G | h | h 1, no less | d | A | b | L, no less | and | |
| - | - | - | - | - | - | ||||||||||
Table 2 of Appendix 18. Structural dimensions of ductless installation of heating networks in reinforced foam concrete insulation in wet soils (with drainage)
| D y, mm | D n, (with a covering layer) | Dimensions according to album series 903-0-1 | |||||||||||||
| D P | D o | A | B | IN | l | k | G | h | h 1, no less | d | A | b | L, no less | and | |
Channel gasket.
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Rice. 2 appendices 18. Prefabricated ducts for heating networks: a) type CL; b) type of CLp; c) KLS type.
Table 3 of Appendix 18. Main types of prefabricated reinforced concrete channels for heating networks.
| Nominal pipeline diameter D y, mm | Channel designation (brand) | Channel dimensions, mm | |||
| Internal nominal | External | ||||
| Width A | Height H | Width A | Height H | ||
| 25-50 70-80 | KL(KLp)60-30 KL(KLp)60-45 | ||||
| 100-150 | KL(KLp)90-45 KL(KLp)60-60 | ||||
| 175-200 250-300 | KL(KLp)90-60 KL(KLp)120-60 | ||||
| 350-400 | CL(CLp)150-60 CL(CLp)210-60 | ||||
| 450-500 | KLS90-90 KLS120-90 KLS150-90 | ||||
| 600-700 | KLS120-120 KLS150-120 KLS210-120 |
Appendix 19. Pumps in heat supply systems .
Rice. 1 appendix 19. Field of characteristics of network pumps.
Table 1 of Appendix 19. Basic specifications network pumps.
| Pump type | Delivery, m 3 /s (m 3 / h) | Head, m | Allowable cavitation reserve, m., not less | Pressure at the pump inlet, MPa (kgf/cm2) no more | Rotation speed (synchronous), 1/s (1/min) | power, kWt | Efficiency, %, not less | Temperature of pumped water, (°C), no more | Pump weight, kg |
| SE-160-50 SE-160-70 SE-160-100 SE-250-50 SE-320-110 SE-500-70-11 SE-500-70-16 SE-500-140 SE-800-55- 11 SE-800-55-16 SE-800-100-11 SE-800-100-16 SE-800-160 SE-1250-45-11 SE-1250-45-25 SE-1250-70-11 SE- 1250-70-16 SE-1250-100 SE-1250-140-11 SE-1250-140-16 SE-1600-50 SE-1600-80 SE-2000-100 SE-2000-140 SE-2500-60- 11 SE-2500-60-25 SE-2500-180-16 SE-2500-180-10 SE-3200-70 SE-3200-100 SE-3200-160 SE-5000-70-6 SE-5000-70- 10 SE-5000-100 SE-5000-160 | 0,044(160) 0,044(160) 0,044(160) 0,069(250) 0,089(320) 0,139(500) 0,139(500) 0,139(500) 0,221(800) 0,221(800) 0,221(800) 0,221(800) 0,221(800) 0,347(1250) 0,347(1250) 0,347(1250) 0,347(1250) 0,347(1250) 0,347(1250) 0,347(1250) 0,445(1600) 0,445(1600) 0,555(2000) 0,555(2000) 0,695(2500) 0,695(2500) 0,695(2500) 0,695(2500) 0,890(3200) 0,890(3200) 0,890(3200) 1,390(5000) 1,390(5000) 1,390(5000) 1,390(5000) | 5,5 5,5 5,5 7,0 8,0 10,0 10,0 10,0 5,5 5,5 5,5 5,5 14,0 7,5 7,5 7,5 7,5 7,5 7,5 7,5 8,5 8,5 22,0 22,0 12,0 12,0 28,0 28,0 15,0 15,0 32,0 15,0 15,0 15,0 40,0 | 0,39 (4) 0,39 (4) 0,39 (4) 0,39 (4) 0,39 (4) 1,08(11) 1,57(16) 1,57(16) 1,08(11) 1,57(16) 1,08(11) 1,57(16) 1,57(16) 1,08(11) 2,45(25) 1,08(11) 1,57(16) 1,57(16) 1,08(11) 1,57(16) 2,45(25) 1,57(16) 1,57(16) 1,57(16) 1,08(11) 2,45(25) 1,57(16) 0,98(10) 0,98(10) 0,98(10) 0,98(10) 0,59(6) 0,98(10) 1,57(16) 0,98(10) | 50(3000) 50(3000) 50(3000) 50(3000) 50(3000) 50(3000) 50(3000) 50(3000) 25(1500) 25(1500) 25(1500) 25(1500) 50(3000) 25(1500) 25(1500) 25(1500) 25(1500) 25(1500) 25(1500) 25(1500) 25(1500) 25(1500) 50(3000) 50(3000) 25(1500) 25(1500) 50(3000) 50(3000) 25(1500) 25(1500) 50(3000) 25(1500) 25(1500) 25(1500) 50(3000) | (120) (180) (180) (120) (180) (120) | - - - - - - - - - - - - - - - - - - |
Table 2 of Appendix 19. Centrifugal pumps type K.
| Pump brand | Productivity, m 3 / h | Total head, m | Wheel rotation speed, rpm | Recommended electric motor power, kW | Impeller diameter, mm |
| 1 K-6 | 6-11-14 | 20-17-14 | |||
| 1.5 K-6a | 5-913 | 16-14-11 | 1,7 | ||
| 1.5 K-6b | 4-9-13 | 12-11-9 | 1,0 | ||
| 2 K-6 | 10-20-30 | 34-31-24 | 4,5 | ||
| 2 K-6a | 10-20-30 | 28-25-20 | 2,8 | ||
| 2 K-6b | 10-20-25 | 22-18-16 | 2,8 | ||
| 2 K-9 | 11-20-22 | 21-18-17 | 2,8 | ||
| 2 K-9a | 10-17-21 | 16-15-13 | 1,7 | ||
| 2 K-9b | 10-15-20 | 13-12-10 | 1,7 | ||
| 3 K-6 | 30-45-70 | 62-57-44 | 14-20 | ||
| 3 K-6a | 30-50-65 | 45-37-30 | 10-14 | ||
| 3 K-9 | 30-45-54 | 34-31-27 | 7,0 | ||
| 3 K-9a | 25-85-45 | 24-22-19 | 4,5 | ||
| 4 K-6 | 65-95-135 | 98-91-72 | |||
| 4 K-6a | 65-85-125 | 82-76-62 | |||
| 4 K-8 | 70-90-120 | 59-55-43 | |||
| 4 K-8a | 70-90-109 | 48-43-37 | |||
| 4 K-12 | 65-90-120 | 37-34-28 | |||
| 4 K-12a | 60-85-110 | 31-28-23 | 14, | ||
| 4 K-18 | 60-80-100 | 25-22-19 | 7,0 | ||
| 4 K-18a | 50-70-90 | 20-18-14 | 7,0 | ||
| 6 K-8 | 110-140-190 | 36-36-31 | |||
| 6 K-8a | 110-140-180 | 30-28-25 | |||
| 6 K-8b | 110-140-180 | 24-22-18 | |||
| 6 K-12 | 110-160-200 | 22-20-17 | |||
| 6 K-12a | 95-150-180 | 17-15-12 | |||
| 8 K-12 | 220-280-340 | 32-29-25 | |||
| 8 K-12a | 200-250-290 | 26-24-21 | |||
| 8 K-18 | 220-285-360 | 20-18-15 | |||
| 8 K-18a | 200-260-320 | 17-15-12 |
Appendix 20. Shut-off valves in heat supply systems.
Table 2 of Appendix 21. Steel butterfly valves with electric drive D y 500-1400 mm at p y =2.5 MPa, t£200°C with weld ends.
| Valve designation | Conditional pass D y, mm | Application limits | Housing material | ||||
| By catalog | In heating networks | ||||||
| p y, MPa | t, °C | p y, MPa | t, °C | ||||
| 30h47br | 50, 80, 100, 125, 150, 200 | 1,0 | 1,0 | Flanged | Gray cast iron | ||
| 31ch6nzh (I13061) | 50, 80, 100, 125, 150 | 1,0 | 1,0 | ||||
| 31h6br | 1,6 | 1,0 | |||||
| 30s14nzh1 | 1,0 | 1,0 | Flanged | Steel | |||
| 31ch6br (GL16003) | 200, 250, 300 | 1,0 | 1,0 | Gray cast iron | |||
| 350, 400 | 1,0 | 0,6 | |||||
| 30h915br | 500, 600, 800, 1200 | 1,0 | 0,6 0,25 | Flanged | Gray cast iron | ||
| 30h930br | 1,0 | 0,25 | |||||
| 30s64br | 2,5 | 2,5 | Steel | ||||
| IA12015 | 2,5 | 2,5 | With weld ends | ||||
| L12014 (30s924nzh) | 1000, 1200, 1400 | 2,5 | 2,5 | ||||
| 30s64nzh (PF-11010-00) | 2,5 | 2,5 | Flanged and butt weld ends | Steel | |||
| 30s76nzh | 50, 80, 100, 125, 150, 200, 250/200 | 6,4 | 6,4 | Flanged | Steel | ||
| 30s97nzh (ZL11025Sp1) | 150, 200, 250 | 2,5 | 2,5 | Flanged and butt weld ends | Steel | ||
| 30s65nzh (NA11053-00) | 150, 200, 250 | 2,5 | 2,5 | ||||
| 30s564nzh (MA11022.04) | 2,5 | 2,5 | |||||
| 30s572nzh 30s927nzh | 400/300, 500, 600, 800 | 2,5 | 2,5 | Flanged and butt weld ends | Steel | ||
| 30s964nzh | 1000/800 | 2,5 | 2,5 |
Table 4 of Appendix 20. Permissible valves
| Valve designation | Conditional arrival D y, mm | Limits of application (no more) | Pipeline connection | Housing material | |||
| By catalog | In heating networks | ||||||
| p y, MPa | t, °C | p y, MPa | t, °C | ||||
| 30h6br | 50, 80, 100, 125, 150 | 1,0 | 1,0 | Flanged | Gray cast iron | ||
| 30h930br | 600, 1200, 1400 | 0,25 | 0,25 | ||||
| 31h6br | 1,6 | 1,0 | |||||
| ZKL2-16 | 50, 80, 100, 150, 200, 250, 300, 350, 400, 500, 600 | 1,6 | 1,6 | Steel | |||
| 30s64nzh | 2,5 | 2,5 | Flanged and butt weld ends | Steel | |||
| 30s567nzh (IA11072-12) | 2,5 | 2,5 | Welding | ||||
| 300s964nzh | 2,5 | 2,5 | Flanged and butt weld ends | Steel | |||
| 30s967nzh (IATs072-09) | 500, 600 | 2,5 | 2,5 | Welding |
Rice. 2 applications 20. Ball valves in heat supply systems.
 |
Table 5 of Appendix 20. Technical data of ball valves.
| Nominal diameter | Nominal bore diameter | Dh, mm | d, mm | t, mm | L, mm | H1 | H2 | A | Weight in kg |
| 17,2 | 1,8 | 0,8 | |||||||
| 21,3 | 2,0 | 0,8 | |||||||
| 26,9 | 2,3 | 0,9 | |||||||
| 33,7 | 2,6 | 1,1 | |||||||
| 42,4 | 2,6 | 1,4 | |||||||
| 48,3 | 2,6 | 2,1 | |||||||
| 60,3 | 2,9 | 2,7 | |||||||
| 76,1 | 76,1 | 2,9 | 4,7 | ||||||
| 88,9 | 88,9 | 3,2 | 6,1 | ||||||
| 114,3 | 114,3 | 3,6 | 9,5 | ||||||
| 139,7 | 3,6 | 17,3 | |||||||
| 168,3 | 4,0 | 26,9 | |||||||
| 219,1 | 4,5 | - | 43,5 | ||||||
| 355,6 | 273,0 | 5,0 | - | 115,0 | |||||
| 323,3 | 5,6 | - | 195,0 | ||||||
| 355,6 | 5,6 | - | 235,0 | ||||||
| 406,4 | 6,3 | - | 390,0 | ||||||
| 508,0 | 166,5 | - | 610,0 |
Note: valve body – steel Art. 37.0; ball – stainless steel; ball seat and oil seal – Teflon + 20% carbon; O-rings are triple ethylene-propylene rubber and Viton.
Appendix 21. Relationship between some units of physical quantities to be replaced with SI units.
Table 1 of Appendix 21.
| Name of quantities | Unit | Relation to SI units | |||
| subject to replacement | SI | ||||
| Name | Designation | Name | Designation | ||
| quantity of heat | kilocalorie | kcal | kilojoule | KJ | 4.19 kJ |
| specific heat | kilocalorie per kilogram | kcal/kg | kilojoule per kilogram | KJ/kg | 4.19kJ/kg |
| heat flow | kilocalorie per hour | kcal/h | watt | W | 1.163 W |
| (power) | gigacalorie per hour | Gcal/h | megawatt | MW | 1.163 MW |
| surface heat flux density | kilocalorie per hour per square meter | kcal/(h m2) | watt per square meter | W/m2 | 1.163 W/m2 |
| volumetric heat flux density | kilocalorie per hour per cubic meter | kcal/(h m 3) | watt per cubic meter | W/m3 | 1.163 W/m3 |
| heat capacity | kilocalorie per degree Celsius | kcal/°С | kilojoule per degree Celsius | KJ/°C | 4.19 kJ |
| specific heat | kilocalorie per kilogram degree Celsius | kcal/(kg°C) | kilojoule per kilogram degree Celsius | KJ/(kg°C) | 4.19kJ/(kg°C) |
| thermal conductivity | kilocalorie per meter hour degrees Celsius | kcal/(m h°C) | watt per meter degree Celsius | W/(m °C) | 1.163W/(m °C) |
Table 2 Relationships between units of measurement of the IKGSS system and the international system of units SI.
Table 3. Relationship between units of measurement
| units of measurement | Pa | bar | mm. rt. st | mm. water st | kgf/cm 2 | Lbf/in 2 |
| Pa | 10 -6 | 7,5024∙10 -3 | 0,102 | 1,02∙10 -6 | 1,45∙10 -4 | |
| bar | 10 5 | 7,524∙10 2 | 1,02∙10 4 | 1,02 | 14,5 | |
| mmHg | 133,322 | 1,33322∙10 -3 | 13,6 | 1,36∙10 -3 | 1,934∙10 -2 | |
| mm water st | 9,8067 | 9,8067∙10 -5 | 7,35∙10 -2 | ∙10 -4 | 1,422∙10 -3 | |
| kgf/cm 2 | 9,8067∙10 4 | 0,98067 | 7,35∙10 2 | 10 4 | 14,223 | |
| Lbf/in 2 | 6,8948∙10 3 | 6,8948∙10 -2 | 52,2 | 7,0307∙10 2 | 7,0307∙10 -2 |
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