Centralized heat supply from large boiler houses. Operation of heat supply systems and boiler installations Installation of a boiler room in a heat supply organization
4.1 The composition of the sections of the design documentation and the requirements for their content are given in.
4.2 Equipment and materials used in the design, in cases established by documents in the field of standardization, must have certificates of compliance with the requirements of Russian norms and standards, as well as permission from Rostekhnadzor for their use.
4.3 When designing boiler houses with steam and hot water boilers with a steam pressure of more than 0.07 MPa (0.7 kgf/cm 2) and with a water temperature of more than 115 ° C, it is necessary to comply with the relevant norms and regulations in the field of industrial safety, as well as documents in the field standardization.
4.4 The design of new and reconstructed boiler houses must be carried out in accordance with heat supply schemes developed and approved in the established manner, or with justifications for investments in construction adopted in regional planning schemes and projects, master plans of cities, towns and rural settlements, residential, industrial and residential planning projects other functional areas or individual objects listed in.
4.5 Design of boiler houses for which the type of fuel is not determined in accordance with the established procedure is not allowed. The type of fuel and its classification (primary, emergency if necessary) is determined in agreement with the regional authorized authorities. The quantity and method of delivery must be agreed upon with fuel supply organizations.
4.6 Boiler houses according to their intended purpose in the heat supply system are divided into:
- central in the district heating system;
- peaks in the centralized and decentralized heat supply system based on the combined production of thermal and electrical energy;
- autonomous decentralized heat supply systems.
4.7 according to purpose are divided into:
- heating - to provide thermal energy to heating, ventilation, air conditioning and hot water supply systems;
- heating and industrial - to provide thermal energy to heating, ventilation, air conditioning, hot water supply, process heat supply systems;
- production - to provide thermal energy to process heat supply systems.
4.8 Boiler houses based on the reliability of supply of thermal energy to consumers (according to SP 74.13330) are divided into boiler houses of the first and second categories.
- boiler houses, which are the only source of thermal energy in the heating system;
- boiler houses providing thermal energy to consumers of the first and second categories who do not have individual backup sources of thermal energy. Lists of consumers by category are established in the design assignment.
4.9 In boiler houses with steam and steam-water heating boilers with a total installed thermal power of more than 10 MW, in order to increase reliability and energy efficiency during feasibility studies, it is recommended to install low-power steam turbine generators with a voltage of 0.4 kV with steam back-pressure turbines to ensure coverage of the electrical loads of the boiler houses’ own needs or the enterprises on whose territory they are located. Exhaust steam after turbines can be used: for process steam supply to consumers, for heating water in heating supply systems, for the own needs of the boiler house.
The design of such installations must be carried out in accordance with.
In water heating boiler houses operating on liquid and gaseous fuels, the use of gas turbine or diesel units is allowed for these purposes.
When designing an electrical power superstructure to generate electrical energy for the boiler house’s own needs and/or transfer it to the network, it should be carried out in accordance with,. If for the development of project documentation the reliability and safety requirements established by regulatory documents are insufficient, or such requirements are not established, special technical conditions should be developed and approved in the prescribed manner.
4.10 To supply heat to buildings and structures from block-modular boiler houses, it should be possible to operate the boiler room equipment without permanently present personnel.
4.11 The estimated thermal power of the boiler room is determined as the sum of the maximum hourly thermal energy consumption for heating, ventilation and air conditioning, the average hourly thermal energy consumption for hot water supply and thermal energy consumption for technological purposes. When determining the estimated thermal power of a boiler house, the consumption of thermal energy for the boiler house’s own needs, losses in the boiler house and in heating networks, taking into account the energy efficiency of the system, must also be taken into account.
4.12 Estimated consumption of thermal energy for technological purposes should be taken according to the design specifications. In this case, the possibility of discrepancies in the maximum thermal energy consumption for individual consumers must be taken into account.
4.13 Estimated hourly consumption of thermal energy for heating, ventilation, air conditioning and hot water supply should be taken according to the design assignment, in the absence of such data - determined according to SP 74.13330, as well as according to recommendations.
4.14 The number and productivity of boilers installed in the boiler room should be selected, ensuring:
- design productivity (thermal power of the boiler room according to 4.11);
- stable operation of boilers at the minimum permissible load during the warm season.
If the boiler with the highest productivity in boiler houses of the first category fails, the remaining boilers must ensure the supply of thermal energy to consumers of the first category:
- for process heat supply and ventilation systems - in an amount determined by the minimum permissible loads (regardless of the outside air temperature);
- for heating and hot water supply - in an amount determined by the regime of the coldest month.
If one boiler fails, regardless of the category of the boiler room, the amount of thermal energy supplied to consumers of the second category must be provided in accordance with the requirements of SP 74.13330.
The number of boilers installed in boiler houses and their productivity should be determined on the basis of technical and economic calculations.
Boiler rooms should provide for the installation of at least two boilers; in industrial boiler houses of the second category - installation of one boiler.
4.15 In boiler house projects, boilers, economizers, air heaters, back-pressure turbines, gas turbine and gas piston units with 0.4 kV generators, ash collectors and other equipment supplied by manufacturers should be used in modular transportable design with full factory and installation readiness.
4.16 Projects of auxiliary equipment units with pipelines, automatic control, regulation, alarm systems and electrical equipment of increased factory readiness are developed according to the orders and assignments of installation organizations.
4.17 Open installation of equipment in various climatic zones is possible if this is permitted by the manufacturers’ instructions and meets the noise characteristics requirements in SP 51.13330 and.
4.18 The layout and placement of the boiler room technological equipment must ensure:
- conditions for mechanization of repair work;
- the possibility of using floor lifting and transport mechanisms and devices during repair work.
To repair equipment units and pipelines weighing more than 50 kg, inventory lifting devices should, as a rule, be provided. If it is impossible to use inventory lifting devices, stationary lifting devices (hoists, hoists, overhead and overhead cranes) should be provided.
4.19 In boiler houses, according to the design assignment, repair areas or premises for carrying out repair work should be provided. In this case, one should take into account the possibility of performing repair work on the specified equipment by the relevant services of industrial enterprises or specialized organizations.
4.20 The main technical solutions adopted in the project must ensure:
- reliability and safety of equipment operation;
- maximum energy efficiency of the boiler room;
- economically justified costs of construction, operation and repair;
- labor protection requirements;
- required sanitary and living conditions for operating and maintenance personnel;
- environmental protection requirements.
4.21 Thermal insulation of boiler room equipment, pipelines, fittings, gas ducts, air ducts and dust pipes should be provided taking into account the requirements of SP 60.13330 and SP 61.13330.
In the same section:
Introduction | 1 area of use |
2. Normative references | 3. Terms and definitions |
4. General provisions | 5. Master plan and transport |
6. Space planning and design solutions |
The boiler plant is used to generate steam with specified parameters for steam engines (turbines, piston engines), as well as for production or heating needs. Depending on the purpose, boiler installations can be energy (servicing power plants), industrial, industrial heating and heating. The purpose of the boiler installation determines its performance and parameters of the generated steam.
The initial working fluid for producing steam in a boiler plant is water, and the initial energy carrier is fuel. The heat released during fuel combustion is transferred through the metal surfaces of heat exchangers to water and steam. The main components of the steam production process in boiler plants are fuel combustion, heat exchange between combustion products and the working fluid, and steam formation.
The boiler installation consists of boiler units and auxiliary devices.
Figure 1. Boiler installation: 1 - trolley for fuel delivery; 2 - metal grill; 3 - fuel bunker; 4 - mechanism for supplying fuel to the firebox; 5 - grate; 6 - firebox; 7 - vertical water tube steam boiler; 8 - steam superheater; 9 - saturated steam steam line; 10 – superheated steam steam line; 11 - dust collector; 12 - water economizer; 13 - feed water pipeline; 14 - air heater; 15 - blower fan; 16 - feed pump; 17- chimney; 18 - lightning conductor; 19 - prefabricated hog; 20 - hogs from other boilers; 21 - rotary draft control valve; 22 - ash bunker; 23 – slag bunker; 24 - trolley for removing slag and ash
The main elements of boiler installation equipment (Fig. 1) include:
steam boiler 7 - a closed heat exchange apparatus heated by flue gases, used to produce saturated steam with a pressure of more than 1 MPa, used outside the apparatus itself;
firebox 6 is a fuel-burning device in which heat is released during fuel combustion;
steam superheater 8 - a heat exchanger heated by flue gases, designed to superheat saturated steam;
economizer 12 - heat exchanger for heating feed water (before it enters the boiler) by using the heat of combustion products;
air heater 14 - a heat exchanger for heating air (before it enters the combustion device) by using the heat of combustion products.
The combination of the main elements of equipment listed above constitutes a boiler unit (abbreviated as boiler unit).
Auxiliary elements of boiler installation equipment include:
a traction unit that sucks flue gases from the flues of boiler units and throws them through the chimney 17 into the atmosphere;
a blowing unit, which is a fan 15 that forces air through air ducts into the firebox;
a feed unit consisting of feed pumps 16 and pipelines designed to supply boilers with water;
water treatment plant designed for chemical purification of feedwater (not shown in Fig. 1);
steam pipelines - steel pipelines 9 and 10 for transporting steam, respectively, between elements of boiler units and from boiler units to consumers;
fuel supply device (trolley) 1 - for supplying fuel from the fuel storage to the boiler room;
fuel bunker 3 (fuel storage) - to form a certain supply of fuel in the boiler room;
ash removal device (elements 22...24) - for removing ash and slag from boiler units and transporting them from the boiler room to dumps;
ash collecting device - devices 11 for collecting fly ash from flue gases at their outlet from boilers in order to combat environmental contamination with ash particles flying out of chimneys.
The productivity of a boiler installation is the sum of the steam output of the individual boilers included in its composition.
Boiler steam production is the amount of steam (in tons or kilograms) produced by the boiler per unit of time. This parameter is designated by the letter D and is measured in t/h, kg/h or kg/s.
An important characteristic of the boiler is its heating surface F, measured in square meters (m2).
The heating surface of the boiler is the area of all surfaces of the metal walls, washed on one side by hot gases, and on the other by the working fluid (water or steam-water mixture). The heating surface is usually calculated from the side heated by gases.
A heating surface that receives heat mainly as a result of radiation from a flame or a burning layer of fuel is called radiation. Radiation heating surfaces that perceive heat solely due to radiation in the firebox are called fire screens. The heating surface to which heat is transferred mainly as a result of contact of hot moving gases with this surface is called convective.
Hot water boilers are installed at thermal power plants to cover peak loads in heating systems, as well as in district and factory boiler houses as the main sources of heat in district heating systems. Boilers are direct-flow units that directly heat water circulating in heating networks. In peak mode, network water is heated to a temperature from 104 to 150 °C, and in the main mode - from 70 to 150 °C.
For heat supply of individual utility buildings or groups of them, cast-iron sectional boilers are produced, the technical characteristics of which are given in Table. 1. The maximum operating pressure in such boilers is 0.6 MPa, water temperature is up to 115 °C. The boilers operate on hard coal and anthracite. When boilers are equipped with appropriate fuel-burning devices, natural gases and heating oil can be used; the thermal power of the boilers in these cases increases.
Technical characteristics of cast iron sectional hot water boilers GOST 10617-83
Boiler type |
Heating surface, m 2 |
Number of sections |
Dimensions, mm |
Weight, kg |
||||||
anthracite |
coal |
Length |
Width |
Height |
||||||
screened |
private |
screened |
private |
|||||||
"Universal-6M" |
||||||||||
"Energy-3M" |
||||||||||
"Minsk-1" |
||||||||||
Notes: 1 . The conditional heating surface area is indicated in parentheses. 2 . The numerator indicates the power of the boiler when operating on coal, the denominator - when operating on gas or fuel oil.
In heating and hot water supply systems of small buildings, small-sized steel and cast iron hot water boilers are used (Table 2), designed for an operating pressure of 0.2 MPa and a water temperature of 90 °C.
Table 2. Technical characteristics of small boilers
Boiler type |
Heating surface, m 2 |
Thermal power, kW, during combustion |
Number of sections |
Dimensions, mm |
Weight, kg |
|||
liquid fuel |
natural gas |
Length |
Width |
Height |
||||
Steel KB (TS) |
||||||||
Cast iron World Cup-2 |
||||||||
Autonomous boilers and boiler installations. The sanitary installations of buildings can conditionally include boiler rooms and heat generators with a thermal power of 3-20 kW to 3000 kW, which have recently been called autonomous (including roof-mounted and block-mounted - mobile), and individual apartment heat generators. They are, as a rule, intended for heat supply to a separate facility (sometimes a small group of nearby facilities) or an individual apartment or cottage.
Features of the design and construction of autonomous boiler houses for different types of civil facilities are different. They are regulated by the set of rules SP 41-104-2000 “Design of autonomous heat supply sources”.
Based on their location in space, autonomous boiler houses are divided into: free-standing, attached to buildings for other purposes, built into buildings for other purposes, regardless of the floor of placement, roof-mounted. The thermal power of the built-in, attached and roof boiler room should not exceed the heat requirement of the building for which it is intended to supply heat.
In some cases, with an appropriate feasibility study, it is possible to use a built-in, attached or roof-mounted autonomous boiler room for heat supply to several buildings, if the heat load of additional consumers does not exceed 100% of the heat load of the main building. But at the same time, the total thermal power of an autonomous boiler house should not exceed the following values: 3.0 MW - for a roof-top and built-in boiler house with boilers using liquid and gaseous fuels; 1.5 MW - for a built-in boiler room with solid fuel boilers. Total thermal power attached boiler rooms not limited.
For production buildings of industrial and agricultural enterprises design and construction of attached, built-in and roof boiler houses is allowed. For boiler rooms, attached for buildings of the specified purpose, the total thermal power of installed boilers, the unit productivity of each boiler and the parameters of the coolant are not standardized.
For boiler rooms, built-in in production buildings of industrial enterprises when using boilers with steam pressure up to 0.07 MPa (0.7 kgf/cm2) and water temperature up to 115 ° C, the thermal power of the boilers is not standardized.
Roof boiler rooms for production buildings of industrial enterprises, it is allowed to design using boilers with steam pressure up to 0.07 MPa (0.7 kgf/cm2) and water temperature up to 115 °C.
For residential buildings, it is allowed to install attached and roof-mounted boiler rooms with the use of hot water boilers with water temperatures up to 115 °C, while the thermal power of the boiler room should not be more than 3.0 MW. It is not allowed to build boiler rooms into residential multi-apartment buildings.
For public, administrative and domestic buildings It is allowed to design built-in, attached and roof-mounted boiler rooms when using:
- - hot water boilers with water heating temperatures up to 115 °C;
- - steam boilers with saturated steam pressure up to 0.07 MPa (0.7 kgf/cm 2), satisfying the condition (/- 100) Kt - saturated steam temperature at operating pressure, °C; V- water volume of the boiler, m3.
It is not allowed to design roof-mounted, built-in and attached boiler houses to buildings of children's preschool and school institutions, to medical buildings of hospitals and clinics with round-the-clock stay of patients, to dormitory buildings of sanatoriums and recreational institutions.
The possibility of installing a roof boiler room on buildings of any purpose above the level of 26.5 m must be agreed with the local authorities of the State Fire Service.
Thermal loads for calculation and selection of boiler room equipment must be defined for three modes:
maximum - at the design temperature of the outside air (during the coldest five-day period);
average - at the average outside temperature in the coldest month;
The indicated design temperatures of outside air are accepted in accordance with SNiP 23-01-99* and SNiP 41-01-2003.
The design productivity of the boiler room is determined by the sum of heat consumption for heating and ventilation at maximum
small mode (maximum heat loads) and heat loads for hot water supply in medium mode and design loads for technological purposes in medium mode. When determining the design productivity of the boiler room, the heat consumption for the boiler room’s own needs, including heating in the boiler room, must also be taken into account.
Maximum heat loads for heating (? 0П1ах, ventilation (?„ max and average heat loads for hot water supply ?) It residential, public and industrial buildings should be accepted according to appropriate projects.
Technological diagrams and layout of boiler room equipment must ensure: optimal mechanization and automation of technological processes, safe and convenient maintenance of equipment; shortest length of communications; optimal conditions for mechanization of repair work; safe operation without permanent maintenance personnel by automating technological processes of individual boiler rooms.
In Fig. Figure 1.19 shows an approximate technological diagram of autonomous heat supply sources.
The water heated in the boiler (primary circuit) enters the heaters, where it heats the secondary circuit water entering the heating, ventilation, air conditioning and domestic hot water systems, and returns to the boiler. In this scheme, the water circulation circuit in the boilers is hydraulically isolated from the circulation circuits of the subscriber systems, which makes it possible to protect the boilers from replenishing them with low-quality water in the presence of leaks, and in some cases to completely abandon water treatment and ensure reliable scale-free operation of the boilers.
Repair areas are not provided for in autonomous and rooftop boiler houses. Repair of equipment, fittings, control and regulation devices must be carried out by specialized organizations that have the appropriate licenses, using their lifting devices and bases.
The equipment of autonomous boiler rooms must be located in a separate room, inaccessible to unauthorized entry by unauthorized people.
For built-in and attached autonomous boiler houses, closed storage warehouses for solid or liquid fuel are provided, located outside the boiler room and the building for which it is intended to supply heat.
- -s^s
expansion tank
heat exchanger
control valve
water treatment at the station
Rice. 1.19. Thermohydraulic diagram of an autonomous (roof) boiler house
Equipment of autonomous heat supply sources. Currently, the domestic industry produces cast iron and steel boilers designed both for burning gas, liquid boiler and furnace fuel, and for layer combustion of sorted solid fuel on grates and in a suspended (vortex, fluidized) state.
If necessary, solid fuel boilers can be converted to burn gaseous and liquid fuels by installing appropriate gas-burning devices or nozzles and automation for them on the front plate.
From small-sized cast iron sectional boilers boilers of the most common brand KChM of various modifications should be mentioned. Small size steel boilers are produced by many machine-building enterprises of various departments, mainly as consumer goods. Compared to cast iron boilers, they are less durable (the service life of cast iron boilers is up to 20 years, steel boilers - 8-10 years), but they are less metal-intensive and not so labor-intensive to manufacture, and are somewhat cheaper on the boiler and equipment market.
All-welded steel boilers are more gas-tight than cast iron boilers. The smooth surface of steel boilers reduces their contamination from the gas side during operation; they are easier to repair and maintain. The efficiency (efficiency) of steel boilers is close to that of cast iron boilers.
In addition to domestic boilers, in recent years, many boilers from foreign companies have appeared on the market of boilers and boiler auxiliary equipment, including French, German, English, Korean, Finnish, etc. All of them are distinguished by high quality workmanship, good automation and control devices, and excellent design. But their retail prices, with the same thermal characteristics, are 3-5 times higher than the price level for Russian equipment, so they are less accessible to the mass buyer.
In autonomous automated boiler houses, it is recommended to use highly efficient fully factory-ready boilers with automated burner units (Fig. 1.20). As a rule, boiler efficiency must be at least 92%. It is advisable to supply enlarged units of equipment and pipelines that are joined at the installation site. The number of boilers in the boiler room must be at least 2.
![](https://i2.wp.com/studref.com/im/40/5240/917865-28.jpg)
Rice. 1.20.
in Zvenigorod
In table 1.7, 1.8 present the technical characteristics of heating boilers for municipal use from the ZIOSAB company.
For roof and built-in boiler rooms It is recommended to use small-sized modular boilers. The design of the boilers should ensure ease of technological maintenance and quick repair of individual components and assemblies.
In boiler houses, water horizontal sectional shell-and-tube and plate water heaters should be used, switched on according to countercurrent coolant flow patterns.
In steam boiler houses Steam-water and capacitive heaters should be used, equipped with safety valves on the side of the heated medium, as well as air and drain devices.
Each steam-water heater must be equipped with a condensate drain or overflow regulator to drain condensate, fittings with shut-off valves for releasing air and draining water, and a safety valve provided in accordance with the requirements of PB 10-115-96 of the Gosgortekhnadzor of Russia.
Table 1.7
Main technical characteristics of ZIOSAB heating boilers for municipal use
Boiler name |
Heat transfer activity, |
Weight, kg |
Dimensions LxWxH, mm |
pressure |
water temperature at the outlet, °C |
Water resistance, kPa |
reaction |
|
ZIOSAB-2000 |
||||||||
ZIOSAB-1000 |
||||||||
ZIOSAB-500 |
||||||||
Stavan-250 |
||||||||
Stay-125 |
Table 1.8
Emission parameters (natural gas/LHT) of ZIOSAB boilers
The performance of water heating installations is determined by the maximum hourly heat consumption for heating, ventilation and air conditioning and the calculated heat consumption for domestic hot water. The number of water heaters must be at least two for each type of load, and in the event of failure of one of them, the remaining ones must provide heat supply in the coldest month mode (for DHW - maximum hourly flow).
In boiler houses, it is recommended to use foundationless pumps, the flow and pressure of which are determined by thermal-hydraulic calculations. The number of pumps in the primary circuit of the boiler room should be at least two, one of which is a backup. The use of twin pumps is allowed. Foundationless pumps in heat consumption systems can be installed without backup (backup pumps are stored in a warehouse).
Considering the small size of autonomous heat supply sources, the number of shut-off valves on pipelines should be the minimum necessary to ensure reliable and trouble-free operation. Installation sites for shut-off and control valves must have artificial lighting.
Expansion tanks must be equipped with safety valves, and no more than one sump filter (or ferromagnetic filter) must be installed on the supply pipeline at the inlet (directly after the first valve) and on the return pipeline in front of control devices, pumps, water and heat meters.
Imported boiler units and boiler rooms must have accompanying documentation in Russian, including a technical passport, start-up and commissioning and maintenance manuals, warranty obligations, addresses of manufacturers, suppliers and service departments accredited in the Russian Federation.
In autonomous boiler houses operating on liquid and gaseous fuels, it is necessary to provide easily removable (in the event of an explosion) enclosing structures at the rate of 0.03 m 2 per 1 m 3 of the volume of the room in which the boilers are located.
Water-chemical operating mode of an autonomous boiler house must ensure the operation of boilers, heat-using equipment and pipelines without corrosion damage and deposits of scale and sludge on internal surfaces. Water treatment technology should be selected depending on the requirements for the quality of feed and boiler water, water for heating and hot water supply systems, the quality of source water and the quantity and quality of discharged wastewater.
For built-in and attached autonomous boiler houses using solid or liquid fuel, a fuel warehouse should be provided, located outside the boiler room and heated buildings, with a capacity calculated based on daily fuel consumption, based on storage conditions, not less than: solid fuel - 7 days; liquid fuel - 5 days.
The number of liquid fuel tanks is not standardized. A closed, unheated warehouse should be provided for storing solid fuel.
Apartment heating systems. The development of market relations in our country has brought to life apartment-by-apartment heat supply systems. Such systems are also used in multi-apartment residential buildings, including those with built-in public spaces. Thus, in Germany, during new construction and reconstruction of old housing stock, apartment-by-apartment heat supply systems are predominantly used, allowing residents to individually use heat generators, account for energy resources and pay them to suppliers. In the USA, such systems have been developing since pre-war times, with payment for heat supply through automatic coin acceptors.
Apartment-by-apartment heat supply - providing heat to heating, ventilation and hot water supply systems for apartments in a residential building. The system consists of an individual heat source - a heat generator, hot water supply pipelines with water taps, heating pipelines with
heating devices and heat exchangers of ventilation systems.
As heat sources for apartment heating systems, it is recommended to use individual heat generators - fully factory-ready automated boilers using various types of fuel, including natural gas, operating without permanent maintenance personnel.
For multi-apartment residential buildings and built-in public premises, heat generators with closed (sealed) combustion chamber, with an automatic safety system that ensures that the fuel supply is stopped when the power supply is cut off, in the event of a malfunction of the protection circuits, when the burner flame goes out, when the coolant pressure drops below the maximum permissible value, when the maximum permissible coolant temperature is reached, or in the event of a violation of smoke removal (Fig. 1.21); with coolant temperature up to 95 °C; with coolant pressure up to 1.0 MPa.
In apartments of residential buildings up to 5 floors high, it is allowed to use heat generators with an open combustion chamber for hot water supply systems (high-speed instantaneous water heaters - AGV, Fig. 4.4, see Chapter 4).
![](https://i2.wp.com/studref.com/im/40/5240/917865-29.jpg)
Atmospheric gas burner
Flow-through heat exchanger
Control panel with self-diagnosis controller
Rice. 1.21. Internal structure of a boiler with atmospheric
gas burner
In apartments, heat generators with a total heating capacity of up to 35 kW can be installed in kitchens, corridors, non-residential premises, and in built-in public premises - in rooms without permanent occupancy.
Heat generators with a total heating capacity of over 35 kW should be placed in one specially designated room. The total heating capacity of heat generators installed in this room should not exceed 100 kW. Schemes for parallel connection of several boilers of the same type are called cascade.
The intake of air necessary for fuel combustion must be carried out:
- - for heat generators with closed combustion chambers by air ducts directly outside the building;
- - for heat generators with open combustion chambers - directly from the premises in which they are installed.
It is clear that with apartment-by-apartment heat supply in multi-storey buildings, additional requirements arise for building structures regarding the installation of chimneys for individual heat generators. Chimneys can also be individual or collective. The chimney must have a vertical direction and not have narrowings; it is prohibited to lay them through residential premises.
Heat generators of the same type can be connected to the collective chimney (for example, with a closed combustion chamber with forced smoke removal), the heat output of which differs by no more than 30% less than the heat generator with the highest heat output. No more than 8 heat generators and no more than one heat generator per floor should be connected to one collective chimney.
Emissions of combustion products should, as a rule, be carried out above the roof of the building. It is allowed, in agreement with the State Sanitary and Epidemiological Supervision authorities of Russia, to emit smoke through the wall of a building, while the smoke exhaust should be taken outside the dimensions of loggias, balconies, terraces, verandas, etc.
The ventilation system in rooms with heat generators must provide the standard air exchange rate, but not less than 1 exchange per hour.
When placing a heat generator in public premises, it is necessary to provide for the installation of a gas control system with automatic shutdown of the gas supply to the heat generator when a dangerous gas concentration in the air is reached - over 10% of the lower concentration limit of natural gas flame propagation.
Maintenance and repair of heat generators, gas pipelines, chimneys and air ducts for outdoor air intake must be carried out by specialized organizations that have their own emergency dispatch service.
PREFACE
“Gas is safe only with technically competent operation
gas boiler room equipment.
The operator's training manual provides basic information about a hot water boiler house operating on gaseous (liquid) fuel, and examines the schematic diagrams of boiler houses and heat supply systems for industrial facilities. The manual also includes:
- basic information from heat engineering, hydraulics, aerodynamics is presented;
- provides information about energy fuels and the organization of their combustion;
- issues of water preparation for hot water boilers and heating networks are covered;
- the design of hot water boilers and auxiliary equipment of gasified boiler houses was considered;
- Gas supply diagrams for boiler houses are presented;
- a description of a number of control and measuring instruments and automatic control and safety automation circuits is given;
- great attention is paid to the operation of boiler units and auxiliary equipment;
- issues on preventing accidents of boilers and auxiliary equipment, providing first aid to victims of an accident were considered;
- Basic information on organizing the efficient use of heat and power resources is provided.
This operator’s training manual is intended for retraining, training in related professions and advanced training of gas boiler house operators, and can also be useful: for students and students in the specialty “Heat and Gas Supply” and operational dispatch personnel when organizing a dispatch service for the operation of automated boiler houses. To a greater extent, the material is presented for hot water boiler houses with a capacity of up to 5 Gcal with gas-tube boilers of the “Turboterm” type.
Preface |
2 |
Introduction |
5 |
CHAPTER 1. Schematic diagrams of boiler houses and heat supply systems |
8 |
1.3. Methods for connecting consumers to the heating network 1.4. Temperature graph of high-quality heating load regulation 1.5. Piezometric graph |
|
CHAPTER 2. Basic information from thermal engineering, hydraulics and aerodynamics |
18 |
2.1. The concept of coolant and its parameters 2.2. Water, water vapor and their properties 2.3. The main methods of heat transfer: radiation, thermal conductivity, convection. Heat transfer coefficient, factors influencing it |
|
CHAPTER 3. Properties energy fuel and its combustion |
24 |
3.1. General characteristics of energy fuel 3.2. Combustion of gaseous and liquid (diesel) fuels 3.3. Gas burner devices 3.4. Conditions for stable operation of burners 3.5. Requirements of the “Rules for the design and safe operation of steam and hot water boilers” for burner devices |
|
CHAPTER 4. Water treatment and water chemical regimes of the boiler unit and heating networks |
39 |
4.1. Quality standards for feed, make-up and network water 4.2. Physico-chemical characteristics of natural water 4.3. Corrosion of boiler heating surfaces 4.4. Water treatment methods and schemes 4.5. Deaeration of softened water 4.6. Complex-metric (trilometric) method for determining water hardness 4.7. Malfunctions in the operation of water treatment equipment and methods for eliminating them 4.8. Graphic interpretation of the sodium cationization process |
|
CHAPTER 5. Construction of steam and hot water boilers. Boiler room auxiliary equipment |
49 |
5.1. Design and principle of operation of steam and hot water boilers 5.2. Steel water-heating fire-tube-smoke boilers for burning gaseous fuels 5.3. Air supply and combustion product removal schemes 5.4. Boiler valves (shut-off, control, safety) 5.5. Auxiliary equipment for steam and hot water boilers 5.6. Set of steam and hot water boilers 5.7. Internal and external cleaning of heating surfaces of steam and hot water boilers, water economizers 5.8. Instrumentation and boiler safety automation |
|
CHAPTER 6. Gas pipelines and gas equipment of boiler houses |
69 |
6.1. Classification of gas pipelines by purpose and pressure 6.2. Gas supply schemes for boiler houses 6.3. Gas control points of hydraulic fracturing (GRU), purpose and main elements 6.4. Operation of gas control points of gas fracturing stations (GRU) of boiler houses 6.5. Requirements of the “Safety Rules in the Gas Industry” |
|
CHAPTER 7. Boiler room automation |
85 |
7.1. Automatic measurements and control 7.2. Automatic (technological) alarm 7.3. Automatic control 7.4. Automatic control of hot water boilers 7.5. Automatic protection 7.6. Control kit KSU-1-G |
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CHAPTER 8. Operation of boiler plants |
103 |
8.1. Operator work organization 8.2. Operational diagram of pipelines of a transportable boiler house 8.3. Operating schedule for a Turbotherm type hot water boiler equipped with a Weishaupt type burner 8.4. Operating instructions for a transportable boiler room (TC) with “Turboterm” type boilers 8.5. Requirement of the “Rules for the design and safe operation of steam and hot water boilers” |
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CHAPTER 9. Accidents in boiler rooms. Actions of personnel to prevent boiler accidents |
124 |
9.1. General provisions. Causes of accidents in boiler rooms 9.2. Operator action in emergency situations 9.3. Gas hazardous work. Work according to the permit and approved instructions 9.4. Fire safety requirement 9.5. Individual protection means 9.6.Providing first aid to victims of an accident |
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CHAPTER 10. Organization of efficient use of heat and power resources |
140 |
10.1. Heat balance and boiler efficiency. Boiler operating map 10.2. Fuel consumption rationing 10.3. Determination of the cost of generated (supplied) heat |
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Bibliography |
144 |
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INTRODUCTION
Modern boiler technology of small and medium productivity is developing in the following directions:
- increasing energy efficiency by comprehensively reducing heat losses and making the most of the energy potential of fuel;
- reducing the size of the boiler unit due to intensification of the fuel combustion process and heat exchange in the firebox and heating surfaces;
- reduction of harmful toxic emissions (CO, NOx, SOv);
- increasing the reliability of the boiler unit.
New combustion technology is implemented, for example, in boilers with pulsating combustion. The combustion chamber of such a boiler is an acoustic system with a high degree of flue gas turbulization. In the combustion chamber of boilers with pulsating combustion there are no burners, and therefore no torch. The supply of gas and air is carried out intermittently at a frequency of approximately 50 times per second through special pulsating valves, and the combustion process occurs throughout the entire combustion volume. When fuel is burned in the furnace, the pressure increases, the rate of combustion products increases, which leads to a significant intensification of the heat exchange process, the possibility of reducing the size and weight of the boiler, and the absence of the need for bulky and expensive chimneys. The operation of such boilers is characterized by low CO and N0 x emissions. The efficiency of such boilers reaches 96 %.
A vacuum water heating boiler from the Japanese company Takuma is a sealed container filled with a certain amount of well-purified water. The boiler firebox is a fire tube located below the liquid level. Above the water level in the steam space, two heat exchangers are installed, one of which is included in the heating circuit, and the other operates in the hot water supply system. Thanks to a small vacuum automatically maintained inside the boiler, the water boils in it at a temperature below 100 o C. Having evaporated, it condenses on the heat exchangers and then flows back. Purified water is not discharged anywhere from the unit, and it is not difficult to provide the required amount. Thus, the problem of chemical preparation of boiler water, the quality of which is an indispensable condition for reliable and long-term operation of the boiler unit, was eliminated.
Heating boilers from the American company Teledyne Laars are water-tube installations with a horizontal heat exchanger made of finned copper pipes. A feature of such boilers, called hydronic, is the ability to use them with untreated network water. These boilers provide for a high speed of water flow through the heat exchanger (more than 2 m/s). Thus, if water causes corrosion of equipment, the resulting particles will be deposited anywhere but in the boiler heat exchanger. If you use hard water, fast flow will reduce or prevent scale formation. The need for high speed led the developers to the decision to minimize the volume of the water part of the boiler. Otherwise, you need a circulation pump that is too powerful and consumes a large amount of electricity. Recently, products from a large number of foreign companies and joint foreign and Russian enterprises have appeared on the Russian market, developing a wide variety of boiler equipment.
Fig.1. Water heating boiler of the Unitat brand of the international company LOOS
1 – burner; 2 – door; 3 – peeping contest; 4 – thermal insulation; 5 – gas-pipe heating surface; 6 – hatch into the water space of the boiler; 7- flame tube (furnace); 8 – pipe for supplying water to the boiler; 9 – pipe for hot water drainage; 10 – exhaust gas duct; 11 – viewing window; 12 – drainage pipeline; 13 – support frame
Modern hot water and steam boilers of low and medium power are often fire-tube or fire-gas tube. These boilers are characterized by high efficiency, low emissions of toxic gases, compactness, high degree of automation, ease of operation and reliability. In Fig. Figure 1 shows a combined fire-gas-tube water-heating boiler of the Unimat brand of the international company LOOS. The boiler has a firebox made in the form of a flame tube 7, washed from the sides with water. At the front end of the flame tube there is a hinged door 2 with two-layer thermal insulation 4. A burner 1 is installed in the door. Combustion products from the flame tube enter the convective gas-tube surface 5, in which they make a two-pass movement, and then leave the boiler through the gas duct 10. Water is supplied to the boiler through pipe 8, and hot water is discharged through pipe 9. The outer surfaces of the boiler have thermal insulation 4. To monitor the torch, a peephole 3 is installed in the door. Inspection of the condition of the outer part of the gas pipe surface can be performed through hatch 6, and the end part of the body - through the inspection window 11. To drain water from the boiler, a drainage pipeline 12 is provided. The boiler is installed on a support frame 13.
In order to assess the efficient use of energy resources and reduce consumer costs for fuel and energy supply, the Law “On Energy Saving” provides for energy surveys. Based on the results of these surveys, measures are being developed to improve the heat and power facilities of the enterprise. These activities are as follows:
- replacement of thermal power equipment (boilers) with more modern ones;
- hydraulic calculation of the heating network;
- adjustment of hydraulic modes of heat consumption facilities;
- regulation of heat consumption;
- elimination of defects in enclosing structures and introduction of energy-efficient structures;
- retraining, advanced training and financial incentives for personnel for the effective use of fuel and energy resources.
For enterprises that have their own heat sources, the training of qualified boiler room operators is necessary. Persons who are trained, certified and have a certificate for the right to service boilers may be allowed to service boilers. This operator's training manual is precisely used to solve these problems.
CHAPTER 1. PRINCIPAL DIAGRAMS OF BOILERS AND HEAT SUPPLY SYSTEMS
1.1. Schematic thermal diagram of a hot water boiler house running on gas fuel
In Fig. Figure 1.1 shows a schematic thermal diagram of a hot water boiler house operating on a closed hot water supply system. The main advantage of this scheme is the relatively low productivity of the water treatment plant and make-up pumps, the disadvantage is the increased cost of equipment for hot water supply subscriber units (the need to install heat exchangers in which heat is transferred from network water to water used for hot water supply needs). Hot water boilers operate reliably only when maintaining a constant flow rate of water passing through them within specified limits, regardless of fluctuations in the consumer’s heat load. Therefore, the thermal circuits of hot water boiler houses provide for the regulation of the supply of thermal energy to the network according to a qualitative schedule, i.e. by changing the temperature of the water leaving the boiler.
To ensure the calculated water temperature at the entrance to the heating network, the scheme provides for the possibility of mixing the required amount of return network water (G per) to the water leaving the boilers through the bypass line. To eliminate low-temperature corrosion of the tail heating surfaces of the boiler to the return network water at its temperature of less than 60 ° C when operating on natural gas and less than 70-90 ° C when operating on low- and high-sulfur fuel oil, hot water leaving the boiler is mixed using a recirculation pump to return network water.
Figure 1.1. Schematic thermal diagram of the boiler room. Single-circuit, dependent with recirculation pumps
1 – hot water boiler; 2-5 - network, recirculation, raw and make-up water pumps; 6- make-up water tank; 7, 8 – heaters of raw and chemically purified water; 9, 11 – make-up water and vapor coolers; 10 – deaerator; 12 – chemical water treatment plant.
Fig.1.2. Schematic thermal diagram of the boiler room. Double-circuit, dependent with hydraulic adapter
1 – hot water boiler; 2-boiler circulation pump; 3- network heating pump; 4- network ventilation pump; 5-DHW pump of the internal circuit; 6- DHW circulation pump; 7-water-water DHW heater; 8-dirt filter; 9-reagent water treatment; 10-hydraulic adapter; 11-membrane tank.
1.2. Schematic diagrams of heating networks. Open and closed heating networks
Water heating systems are divided into closed and open. In closed systems, water circulating in the heating network is used only as a coolant, but is not taken from the network. In open systems, water circulating in the heating network is used as a coolant and is partially or completely removed from the network for hot water supply and technological purposes.
The main advantages and disadvantages of closed water heating systems:
- stable quality of hot water supplied to subscriber installations, not different from the quality of tap water;
- ease of sanitary control of local hot water supply installations and control of the density of the heating system;
- complexity of equipment and operation of hot water supply user inputs;
- corrosion of local hot water supply installations due to the entry of non-deaerated tap water into them;
- scale formation in water-water heaters and pipelines of local hot water supply installations with tap water with increased carbonate (temporary) hardness (W to ≥ 5 mEq/kg);
- With a certain quality of tap water, in closed heating systems it is necessary to take measures to increase the anti-corrosion resistance of local hot water supply installations or to install special devices at customer inputs for deoxygenation or stabilization of tap water and for protection against contamination.
The main advantages and disadvantages of open water heating systems:
- the possibility of using low-potential (at temperatures below 30-40 o C) industrial thermal resources for hot water supply;
- simplifying and reducing the cost of subscriber inputs and increasing the durability of local hot water supply installations;
- the possibility of using single-pipe lines for transit heat;
- increasing complexity and cost of station equipment due to the need to construct water treatment plants and make-up devices designed to compensate for water costs for hot water supply;
- water treatment must provide clarification, softening, deaeration and bacteriological treatment of water;
- instability of the water supplied to the water supply, according to sanitary indicators;
- complication of sanitary control over the heat supply system;
- complication of control of the tightness of the heat supply system.
1.3. Temperature graph of high-quality heating load regulation
There are four methods for regulating the heating load: qualitative, quantitative, qualitative-quantitative and intermittent (bypass). Qualitative regulation consists of regulating heat supply by changing the temperature of hot water while maintaining a constant quantity (flow) of water; quantitative – in the regulation of heat supply by changing the water flow rate at a constant temperature at the entrance to the controlled installation; qualitative-quantitative – in regulating heat supply by simultaneously changing water flow and temperature; intermittent, or, as it is commonly called, regulation by passes - in the regulation of heat supply by periodically disconnecting heating installations from the heating network. The temperature schedule for high-quality regulation of heat supply for heating systems equipped with convective-radiative heating devices and connected to the heating network using an elevator circuit is calculated based on the formulas:
T 3 = t vn.r + 0.5 (T 3p – T 2p) * (t vn.r – t n)/ (t vn.r – t n.r)+ 0.5 * (T 3p + T 2p -2 * t vn.p) * [ (t vn.r – t n)/ (t vn.r – t n.r)] 0.8 . T 2 = T 3 -(T 3p – T 2p) * (t int.r – t n)/ (t int.r – t n.r). Т 1 = (1+ u) * Т 3 – u * Т 2
where T 1 is the temperature of the network water in the supply line (hot water), o C; T 2 – temperature of water entering the heating network from the heating system (return water), o C; T 3 – temperature of water entering the heating system, o C; t n – outside air temperature, o C; t in – internal air temperature, o C; u – mixing coefficient; the same designations with the index “p” refer to the design conditions. For heating systems equipped with convective-radiative heating devices and connected directly to the heating network, without an elevator, u = 0 and T 3 = T 1 should be taken. The temperature graph of qualitative regulation of heat load for the city of Tomsk is shown in Fig. 1.3.
Regardless of the adopted central control method, the water temperature in the supply pipeline of the heating network must not be lower than the level determined by the hot water supply conditions: for closed heating systems - not lower than 70 o C, for open heating systems - not lower than 60 o C. Water temperature in the supply pipeline on the graph looks like a broken line. At low temperatures tn< t н.и (где t н.и – наружная температура, соответствующая излому температурного графика) Т 1 определяется по законам принятого метода центрального регулирования. При t н >t n. and the water temperature in the supply pipeline is constant (T 1 = T 1i = const), and the regulation of heating installations can be carried out both quantitatively and intermittently (local skips) method. The number of hours of daily operation of heating installations (systems) at this range of outside air temperatures is determined by the formula:
n = 24 * (t vn.r – t n) / (t vn.r – t n.i)
Example: Definition of temperatures T 1 and T 2 to construct a temperature graph
T 1 = T 3 = 20 + 0.5 (95- 70) * (20 – (-11) / (20 – (-40) + 0.5 (95+ 70 -2 * 20) * [(20 – (-11) / (20 – (-40)] 0.8 = 63.1 o C. T 2 = 63.1 – (95-70) * (95-70) * (20 – (-11) = 49.7 o C
Example: Determining the number of hours of daily operation of heating installations (systems) at the outside air temperature range t n > t n.i. The outside air temperature is t n = -5 o C. In this case, the heating installation should operate daily
n = 24 * (20 – (-5) / (20 – (-11) = 19.4 hours/day.
1.4. Piezometric graph of a heating network
Pressures at various points of the heating supply system are determined using water pressure graphs (piezometric graphs), which take into account the mutual influence of various factors:
- geodetic profile of the heating main;
- network pressure losses;
- height of the heat consumption system, etc.
The hydraulic operating modes of the heating network are divided into dynamic (when the coolant circulates) and static (when the coolant is at rest). In static mode, the pressure in the system is set 5 m above the highest water position in it and is depicted by a horizontal line. There is one static pressure line for the supply and return pipelines. The pressures in both pipelines are equalized, since the pipelines are connected using heat consumption systems and mixing jumpers in the elevator units. The pressure lines in dynamic mode for the supply and return pipelines are different. The slopes of the pressure lines are always directed along the flow of the coolant and characterize the pressure losses in the pipelines, determined for each section according to the hydraulic calculation of the heating network pipelines. The position of the piezometric graph is selected based on the following conditions:
- the pressure at any point in the return line should not be higher than the permissible operating pressure in the local systems. (no more than 6 kgf/cm 2);
- the pressure in the return pipeline should ensure that the upper devices of local heating systems are flooded;
- the pressure in the return line, in order to avoid the formation of a vacuum, should not be lower than 5-10 m.w.c.;
- the pressure on the suction side of the network pump should not be lower than 5 mWG;
- the pressure at any point in the supply pipeline must be higher than the boiling pressure at the maximum (design) temperature of the coolant;
- the available pressure at the end point of the network must be equal to or greater than the calculated pressure loss at the subscriber input for the calculated coolant flow.
In most cases, when moving the piezometer up or down, it is not possible to establish such a hydraulic mode in which all connected local heating systems could be connected according to the simplest dependent circuit. In this case, you should focus on installing pressure regulators, pumps on the jumper, on the return or supply input lines at the consumer inputs, or choose connection according to an independent scheme with the installation of heating water-water heaters (boilers) at the consumers. The piezometric graph of the heating network operation is shown in Fig. 1.4
List the main elements of the heat supply system. Define open and closed heating networks, name the advantages and disadvantages of these networks.
- Write down on a separate sheet the main equipment of your boiler room and its characteristics.
- What kind of heating networks do you know by design? What temperature schedule does your heating network follow?
- What purpose does a temperature graph serve? How is the break point of a temperature graph determined?
- What purpose does a piezometric graph serve? What role do elevators, if you have them, play in thermal units?
- On a separate sheet, list the operating features of each element of the heat supply system (boiler, heating network, heat consumer). Always take these features into account in your work! The operator's training manual, together with a set of test tasks, should become a reference book for an operator who respects his work.
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