RU2716202C1 - Operating method of hot-water boiler - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: invention relates to heat power engineering. Method of hot-water boiler operation consists in the fact that hot water flow at the outlet of hot-water boiler is divided into two parts: one part of heat carrier is directed to supply line of heat network in amount required for coating of heat load of consumer, and the other part is directed through the heating circuit make-up circuit elements and mixed with the mains water after the mains pump. Flue gases coming from the hot-water boiler are directed to the snow melting unit, in which the snow mass is processed due to use of excessive heat contained in the outgoing gases of the hot-water boiler. At that, one part of melt water formed as a result of melting snow mass in snow melting plant is directed to storm water sewage treatment facilities, another part of melt water is pumped to raw water pipeline.

EFFECT: invention is aimed at utilization of snow mass due to heat of exit gases without additional costs for fuel.

1 cl, 2 tbl, 1 dwg

Description

The invention relates to the field of thermal energy and is intended for use in utilities for the disposal of snow and ice.

One of the sources of heat supply in the city, are boiler rooms that operate only in the heating period. These are the so-called seasonal boiler houses, consisting mainly of boilers. These boilers are designed to operate on two types of fuel: natural gas and fuel oil. It is known that when boilers run on liquid fuel, in order to avoid the danger of lowering the temperature of the exhaust gases below the dew point, this temperature should be 110 ° C-120 ° C. For this reason, and also due to a number of other circumstances, the temperature of the flue gases of the boilers included in these boiler houses is much higher than 100 ° С. However, it is also known that heating boilers operating within the city consume only natural gas, the dew point of which is at the level of 50 ° С-60 ° С. Thus, the flue gases of hot water boilers operating as part of a seasonal boiler house contain a certain amount of unused heat that could be used to utilize the snow mass after a number of changes have been made to the technology of operation of the boiler circuit, which is the subject of the claimed invention.

Known scheme with hot water boilers [Delyagin G.N., Lebedev V.I., Permyakov B.A. Heat-generating installations, M., Stroyizdat, 1986, p. 406-407, fig. 10.3], including a hot water boiler, with exhaust gas to the chimney, and auxiliary equipment. In this scheme, water from the return line of the heating network is mixed with make-up water, and is supplied to the hot water boiler by a network pump. The flow of hot water at the outlet of the boiler is divided into two parts: one part of the coolant is sent to the supply line of the heating network, and the other part passes through the elements of the heating circuit and is mixed with mains water after the mains pump. Raw water from the water supply system is fed into the feed line of the heating system using a feed pump. The flue gases leaving the boiler are emitted through the chimney into the atmosphere.

The disadvantage in this scheme is the lack of use of the heat of the flue gases of the boiler to increase the energy efficiency of the boiler house in general, and the possibility of its use for utilization of snow mass, in particular.

Known stationary snow melting installation of the circulation type [Patent, utility model No. 129945, IPC E01H 5/10. Stationary snow-melting plant of circulation type / Moiseev V.I., Tuvalbaev B.G.], used for disposal of snow-ice mass obtained during the cleaning of urban areas. It is a rectangular channel with local technological recesses, hydraulic and mechanical devices. The main source of energy for the proposed utility model is the thermal energy of the circulating water discharged from the condensing unit of the thermal power plant into the environment, and / or the heated process waste water of an energy or industrial enterprise. This utility model completely eliminates the operational costs associated with the acquisition and use of fossil fuels for the disposal of snow and ice mass; significantly reduce emissions of harmful substances into the atmosphere; to achieve savings in heat energy of the supply source by increasing the heat load of a CHPP or a heating boiler; significantly speed up the process of disposal (thawing) of snow-ice mass; significantly reduce operating costs associated with transporting the coolant or fuel to the disposal site of the snow-ice mass; to exclude the use of expensive urban land for the placement of snow melting points.

However, this model is applicable only when using waste water from energy and industrial enterprises as thermal energy and is not suitable for using the excess heat contained in the flue gases of boilers or power boilers

Known stationary snow melting installation on the basis of thermal power plants [Utility Model Patent No. 165483, IPC E01H 5/10. Stationary snow melting plant based on a thermal power plant / Zamaleev MM, Sharapov VI, Gubin IV, Pavlov VA, Yaparov IV], which contains a snow melting chamber with a surface heat exchanger. The inlet pipe of the surface heat exchanger of the stationary snow-melting installation is connected via a heating medium to the return network water pipe between the first lift network pump and the flow regulator, and the outlet pipe of the surface heat exchanger of the stationary snow-melting installation is connected through the heating medium to the return network water pipe between the flow regulator and the lower network heater, while the snow melting chamber of the stationary snow melting installation is configured to connect in summer, to the storm sewer pipeline for supplying rainwater from the territory of the cogeneration plant.

However, this snow melting model is applicable on the basis of a thermal power plant, and uses the heat of only return network water, and is not suitable for using the excess heat contained in the flue gases of boilers or power boilers.

Known peak boiler room [Patent for the invention No. 2184311, IPC F22D 1/00. Peak boiler room / Sharapov V.I., Orlov M.E., Rotov P.V.], which contains a boiler, included in the network pipeline, a vacuum makeup water deaerator with pipelines of source water, a heating agent and deaerated make-up water, the latter of which it is connected to the network pipeline, the heating agent pipeline is, at the same time, connected to the vacuum deaerator through the first surface heat exchanger along the flue gas located in the gas duct of the boiler, and the source water pipe is connected to the vacuum to a smart deaerator through the second surface heat exchanger located in this duct along the flue gas. In this method of operation of a hot water boiler, the heat of the flue gases is used to heat the heating agent and the source water in surface heat exchangers. This allows you to abandon the use of network water for heating the source water in front of the deaerator, to provide the necessary temperature regime of vacuum deaeration, by utilizing the heat of the flue gases.

However, in this method, the heat of the flue gases is not used to utilize the snow-ice mass obtained by cleaning urban areas.

Known combined system based on a boiler room [Invention patent No. 2261335, IPC F01K 7/12. Combined system for the simultaneous production of heat and electric energy on the basis of a hot water boiler plant / Kirillov NG, Kovalev VV], which contains a hot water boiler, a heat supply system for consumers with a network pump and a feed water line, a Stirling engine with an electric generator on one shaft, an intermediate heating circuit located in the chimney of the boiler installation, while the intermediate circuit passes through the heater of the Stirling engine, and the make-up water line passes through the cold nik Stirling engine.

The implementation of this invention allows to generate additional electrical energy, reduce cost and increase the efficiency of the heat power system when transferring a hot water boiler to a mini-thermal power plant.

However, in this combined system based on a hot water boiler, the heat of the exhaust gases through the heat exchanger is used only to drive the Stirling engine and generate electricity, and is not used to utilize the snow-ice mass obtained by cleaning urban areas.

Known thermal circuit of a boiler room [Utility Model Patent No. 158799, IPC F22B 33/18. The thermal diagram of the boiler / Bannikov A.V., Vasiliev S.V.], which contains a boiler connected to the supply and return pipelines of the heating system water network, network and recirculation pump, make-up water preparation system, low-boiling working agent circuit, including a turbine with an electric generator, a heat exchanger-evaporator, a condenser and a feed pump. The flue gases leaving the boiler are directed to a heat exchanger-evaporator, which is additionally integrated into the boiler flue, where it is heated, vaporized and overheated with a low-boiling working agent, which is then sent to a turbine with an electric generator to generate electricity.

The implementation of this scheme of a hot-water boiler room allows to increase the energy efficiency of the boiler room by utilizing the heat of the exhaust gases and the heat of condensation of the working agent in the condenser.

However, in this utility model, the heat of the flue gases of the boiler is used only to heat the low-boiling working agent in the heat exchanger-evaporator sent to the turbine to generate electricity, and it is also not used to utilize the snow-ice mass obtained during the cleaning of urban areas.

The technical problem of the proposed technical solution is the need to develop a method of operation of a boiler house, allowing the use of the heat of the exhaust gases to melt the snow mass without additional fuel costs.

The technical result consists in using the heat of the exhaust gases to melt the snow mass without additional fuel costs.

The essence of the claimed invention lies in the fact that in the method of operation of a hot water boiler, the flow of hot water at the outlet of the hot water boiler is divided into two parts: one part of the coolant is sent to the supply line of the heat network in the amount necessary to cover the consumer’s heat load, and the other part is sent through the elements heating circuit and mixed with mains water after the mains pump, the flue gases leaving the boiler are sent to a snow melting plant, in which the snow ma sy by using excess heat contained in the flue gas of the boiler.

The invention is illustrated in the drawing: FIG. - the method of operation of the boiler room.

The thermal diagram of the boiler house includes a boiler 1 connected to the supply and return pipelines of the network water of the heating system; network pump 2 and recirculation pump 12; a make-up water preparation system, a gas supply line to the boiler 13 and an air supply line to the boiler 14; a snow melting plant 15 connected through a pipe 17 and a melt water pump 22 to a raw water pipeline, and also connected to a drain line of melt water to a treatment plant 16; flue gas bypass 19; chimney 20.

The make-up water preparation system comprises a raw water pump 3; raw water heater 4; dry cleaning filters 5; Heated water heater 6; vacuum deaerator 7; vapor cooler 8; water jet ejector 9; supply tank 10; a pump for supplying water to the ejector 11 and a makeup pump 18.

The method of operation of the boiler is as follows.

The water from the return line of the heating network is mixed with make-up water, and the network pump is fed into the boiler 1. The flow of hot water at the outlet of the boiler 1 is divided into two parts: one part of the heat carrier is sent to the supply line of the heating network, and the other part is sent through the heater chemically purified water 6, then through the raw water heater 4 and using a recirculation pump 12 serves in the network water circuit in the pipeline after the network pump 2.

Raw water from the water supply using a make-up pump 3 is heated by a stream of hot water from a boiler 1 in a raw water heater 4, chemically purified in a filter 5, and then divided into two streams. One stream is heated in a chemically purified water heater 6 with a portion of hot water from the boiler 1, the other stream is directed to the vapor cooler 8.

The vapor-air mixture from the deaerator 7 is sent to the vapor cooler 8, where water vapor is condensed and sent back to the column of the deaerator 7.

Vacuum in the deaerator is created by a water-water ejector 9, in the circuit of which a tank 10 and a pump 11 are included.

After the deaerator 7, the make-up water is fed through the make-up pump 18 to the return mains water pipe to the mains pump 2.

The flue gases leaving the boiler during the heating season, accompanied by a large amount of snow falling, are sent through a gas duct 21 to a snow melting plant 15, in which the snow mass is utilized by using the excess heat contained in the flue gases of the boiler, and then it is thrown into the chimney the atmosphere. In the non-heating period, the flue gases leaving the boiler through the bypass duct 19, bypassing the snow melting plant 15, are sent to the chimney 20. To remove debris, the design of the snow melting plant requires a special grate.

Melt water resulting from the melting of the snow mass loaded into the snow melting plant is divided into two streams at the outlet of the snow melting plant. One stream through the drain line of melt water 16 is directed to the treatment facilities of storm sewers, the other stream using a pump of melt water 22 is sent to the raw water pipeline to the raw water pump 3.

Reducing the amount of melt water sent to the sewage treatment plant will reduce the environmental impact of the boiler in the form of payments for environmental pollution. The fact is that the discharge of melt water into the city's storm sewers is accompanied by a payment for the pollution of the hydrosphere [Federal Law dated 10.01.2002 No. 7-FZ (as amended on 07.29.2018) “On Environmental Protection”. Article 16. Payment for negative impact on the environment].

As an example, consider the method of operation of a hot water boiler with a snow melting plant. Table 1 presents the initial data of the equipment adopted for the calculation.

Table 2 presents the calculation results of the heat scheme of the boiler room when using the heat of the exhaust gases to melt the snow mass in a snow melting plant.

From table 2 it can be seen that when the temperature of the exhaust gases decreases from 160 ° C to 100 ° C, the amount of heat in the amount of 921.08 kJ / kg is released. Using this amount of heat will allow melt the snow mass, for 120 days of operation of the snow melting plant, in the amount of 37819.3 tons. This, in turn, will release a certain amount of freight vehicles that should have been used to transport snow.

The payment for the discharge of melt water into the storm sewer will amount to 11.346 million rubles. If you use melt water instead of the part of the raw water used to feed the heating system, the fee for discharging melt water into the storm sewer will decrease by 33% and amount to 7.634 million rubles.

Thus, the proposed technical solution allows you to:

- utilization of snow mass in a snow melting plant based on a boiler house due to the use of excess heat contained in the flue gases of the boiler without additional costs associated with the acquisition and use of fossil fuels;

- reduce the environmental impact of the snowmaking installation on storm urban sewers;

- reduce operating costs associated with the use of trucks for transporting snow to snow dumps or using special snow melting plants for melting snow;

- to exclude the use of expensive urban land for the placement of snow melting points.

Claims (1)

The method of operation of the boiler, which consists in the fact that the water from the return line of the heating network is mixed with make-up water and the network pump is fed into the boiler, the raw water from the water supply is sent to the make-up water supply line, the flow of hot water at the outlet of the boiler is divided into two parts: one part of the coolant is sent to the supply line of the heating network, and the other part of the coolant is sent through the elements of the heating network make-up circuit and mixed with mains water after the mains pump, excellent characterized in that the exhaust gases after the boiler are directed to a snow melting plant, in which the snow mass is recycled by using the excess heat contained in the exhaust gases of the boiler, while one part of the melt water formed as a result of the melting of the snow mass in the snow melting plant, sent to the sewage treatment plant, another part of the melt water is pumped into the raw water pipeline with a pump.

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