CN210004623U

CN210004623U - gas boiler heating system capable of deeply recovering flue gas waste heat

Info

Publication number: CN210004623U
Application number: CN201920649399.4U
Authority: CN
Inventors: 杨艳; 杨济宁; 胡静洋; 张言智
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-05-07
Filing date: 2019-05-07
Publication date: 2020-01-31
Anticipated expiration: 2029-05-07

Abstract

gas boiler heating system for deeply recycling flue gas waste heat, which comprises a gas boiler 1, a steam turbine 2, a compressor 3, a condenser 4, an evaporator 5, a throttle valve 6, a flue gas-water heat exchanger 7, a condenser 8 and a circulating pump 9, wherein the boiler 1 is connected with the steam turbine 2 and the circulating pump 9, the steam turbine 2 is connected with the boiler 1, the condenser 8 and the compressor 3, the condenser 8 is connected with the steam turbine 2 and the circulating pump 9, the compressor 3 is connected with the steam turbine 3, the condenser 4 and the evaporator 5, the condenser 4 is connected with the compressor 3, the throttle valve 6, the condenser 8 and the flue gas-water heat exchanger 7, the evaporator 5 is connected with the compressor 3, the throttle valve 6 and the flue gas-water heat exchanger 7, and the flue gas-water heat exchanger 7 is connected with the boiler 1, the evaporator 5 and the condenser 4.

Description

gas boiler heating system capable of deeply recovering flue gas waste heat

Technical Field

The utility model belongs to the technical field of the energy utilization, especially relate to gas steam boiler's heating technology.

Background

The common heat source in the conventional centralized heating technology is a gas boiler which directly heats hot water or prepares steam to heat the hot water, and high-temperature flue gas generated by a burner can reach more than 1000 ℃, so that the high-temperature flue gas is only used for heating and preparing hot water below 130 ℃, and the high-temperature flue gas has large heat exchange temperature difference, thereby causing the process to have obvious irreversible loss and lower fire efficiency. If high-temperature and high-pressure steam is prepared from high-temperature flue gas generated by a high-grade combustor, heat supply network water is not directly heated, and a compression type heat pump is driven by a steam turbine to recover waste heat of exhaust smoke of a boiler through work, so that irreversible loss in a hot water preparation process can be remarkably reduced, the exhaust smoke temperature is reduced, and meanwhile, the energy utilization efficiency of a system is improved and the beneficial effect of irreversible loss is reduced.

Disclosure of Invention

In order to fully utilize high-temperature and high-grade flue gas generated by a burner of a gas boiler, a mode of preferentially preparing high-temperature and high-pressure steam is adopted, the prepared steam is used for driving a steam turbine to drive a compression type heat pump, the compression type heat pump recovers waste heat of exhaust smoke, simultaneously heats heat supply network water, and a condenser is additionally arranged for recovering waste heat of exhaust steam of the steam turbine. Compared with the existing gas boiler hot water preparation system, the system has the advantages that the exhaust gas temperature is obviously reduced, the waste heat of the flue gas is deeply recovered (the exhaust gas temperature can reach below 10 ℃), the energy utilization efficiency of the gas is improved, and the irreversible loss in the heat exchange process is reduced. In addition, because the content of water vapor in the fuel gas flue gas is higher, the water vapor in the flue gas is condensed after the temperature of the flue gas is deeply reduced, the flue gas washing effect is achieved, and further the system can achieve the effects of energy conservation and emission reduction.

The system comprises a gas boiler 1, a steam turbine 2, a compressor 3, a condenser 4, an evaporator 5, a throttle valve 6, a flue gas-water heat exchanger 7, a condenser 8, a circulating pump 9, a gas inlet 10, a flue gas outlet 11, a heat supply network backwater inlet 12 and a heat supply network backwater outlet 13.

The utility model discloses be different from the technical characteristic that current gas boiler prepared hot water system and not adopt hot water direct heating or prepare the hot-water mode of steam heating, but adopt gas boiler at first to prepare high-temperature highly compressed steam, adopt this high-grade steam priority drive steam turbine, the steam turbine drives the compressor, and the exhaust steam of doing the work in the steam turbine gets into the condenser and becomes liquid water after being cooled by the heat supply network return water, and liquid water is sent back to gas boiler reciprocating cycle by the circulating pump again. Meanwhile, the flue gas generated by the boiler is not directly discharged, but passes through the flue gas-water heat exchanger and the evaporator in sequence to realize a secondary cooling process, so that the flue gas temperature is deeply reduced, the flue gas waste heat is recovered, and the beneficial effects of condensing the water vapor in the flue gas and washing the flue gas are realized.

The system consists of two internal cycles, wherein are water cycles, are Freon cycles, the water cycles consist of a gas boiler 1, a steam turbine 2, a condenser 8 and a circulating pump, liquid water is heated by high-temperature flue gas generated by gas combustion in the gas boiler 1 to be changed into high-temperature high-pressure water vapor, the water vapor enters the steam turbine 2 to do work and then is changed into low-temperature low-pressure exhaust steam, the exhaust steam enters the condenser 8 to be cooled by hot water return water to be changed into liquid water, the liquid water is sent to the gas boiler 1 through the circulating pump 9 to be circulated in a reciprocating mode, the Freon cycles consist of a compressor 3, a condenser 4, an evaporator 5 and a throttle valve 6, the compressor 3 is driven by the steam turbine 2 to compress Freon vapor to heat and boost the temperature of the Freon vapor, the Freon vapor heats a heating network return water in the condenser 4 to be changed from a vapor state to a liquid state, the liquid Freon enters the throttle valve 6 to reduce the temperature and the pressure, then enters the evaporator 5, the gas is heated by the flue gas in the evaporator 5 to be changed into a.

The return water of the heat supply network in the system sequentially goes through the heating process for three times, firstly, the return water of the heat supply network enters the condenser 8 from the return water inlet 12 of the heat supply network and is heated by the exhaust steam at the outlet of the steam turbine 2, secondly, the return water of the heat supply network is heated by the condenser 4, and finally, the return water of the heat supply network leaves the system from the return water 13 of the heat supply network after being heated by the flue gas-water heat exchanger 7 to reach the required water supply temperature and is sent to a heat user.

In the system, flue gas generated by combustion in the gas boiler 1 undergoes two cooling processes, the flue gas firstly enters the flue gas-water heat exchanger 7 to be cooled by return water of a heat supply network, and then the flue gas continuously enters the evaporator 5 to be cooled by Freon medium, and finally the flue gas leaves the system.

The working principle of the system is as follows: the gas enters the gas boiler 1 from the gas inlet 10 and then is combusted to generate high-temperature flue gas, the high-temperature flue gas heats liquid water passing through the circulating pump 9 to form high-temperature high-pressure steam, the high-temperature high-pressure steam enters the steam turbine 2 to do work, blades in the steam turbine 2 are pushed by the steam to drive the compressor 3 through the rotating shaft, the high-temperature high-pressure steam is changed into low-temperature low-pressure exhaust steam after doing work in the steam turbine, the exhaust steam enters the condenser 8 and then is cooled by return water of a heat supply network to form liquid from a steam state, and the liquid water returns to the gas boiler after. Meanwhile, the flue gas discharged by the gas boiler firstly enters the flue gas-water heat exchanger 7 to be cooled by the backwater of the heat supply network, the flue gas continuously enters the evaporator 5 to be cooled again, and finally the flue gas leaves the system from the flue gas outlet 11. Meanwhile, Freon steam generated in the evaporator 5 is compressed, heated and boosted after entering the compressor 3, then enters the condenser 4 and then heats the heat supply network for returning water, the Freon steam is changed into liquid from a vapor state to release condensation heat, and the liquid Freon enters the throttle valve 6, is subjected to temperature reduction and pressure reduction and then enters the evaporator 5 to be heated by smoke gas to be changed into vapor state Freon. The return water of the heat supply network is sequentially heated by the condenser 8, the condenser 4 and the flue gas-water heat exchanger 7, and simultaneously the flue gas is sequentially cooled in the flue gas-water heat exchanger 7 and the evaporator 5.

A steam turbine 2 of the system is connected with a gas boiler 1, a condenser 8 and a compressor 3, the condenser 8 is connected with the steam turbine 2 and a circulating pump 9, the compressor 3 is connected with the steam turbine 2, an evaporator 5 and a condenser 4, a throttle valve 6 is connected with the evaporator 5 and the condenser 4, and a flue gas-water heat exchanger 7 is connected with the gas boiler 1 and the evaporator 5.

Drawings

FIG. 1 is a schematic flow diagram of a heating system of an deep-recovery flue gas waste heat gas-fired boiler.

Reference numerals: the method comprises the following steps of 1-a gas boiler, 2-a steam turbine, 3-a compressor, 4-a condenser, 5-an evaporator, 6-a throttle valve, 7-a flue gas-water heat exchanger, 8-a condenser, 9-a circulating pump, 10-a gas inlet, 11-a flue gas outlet, 12-a heat supply network backwater inlet and 13-a heat supply network backwater outlet.

Detailed Description

The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention and should not be construed as limiting the present invention, and all other embodiments obtained by those skilled in the art without creative work are within the scope of the present invention.

An implementation of the system is now illustrated:

the freon circulating medium in the compressor 3, the evaporator 5, the condenser 4 and the throttle valve 6 is R245fa, and the circulating medium in the gas boiler 1, the steam turbine 2, the condenser 8 and the circulating pump 9 is water.

The gas is burnt to generate high-temperature flue gas after entering the gas boiler 1, the high-temperature flue gas heats liquid water passing through the circulating pump 9 to become high-temperature high-pressure steam, the high-temperature high-pressure steam enters the steam turbine 2 to do work, blades in the steam turbine 2 are pushed by steam to drive the compressor 3 through the rotating shaft, the high-temperature high-pressure steam turns into low-temperature low-pressure exhaust steam after doing work in the steam turbine, the exhaust steam enters the condenser 8 and is cooled by return water of a heat supply network to become liquid from a steam state, and the liquid water returns to the gas boiler after passing through the circulating pump. Meanwhile, the flue gas discharged by the gas boiler firstly enters the flue gas-water heat exchanger 7 to be cooled by the backwater of the heat supply network, and the flue gas continuously enters the evaporator 5 to be cooled again. Meanwhile, R245fa steam generated in the evaporator 5 enters the compressor 3 and is compressed, the temperature and the pressure are raised, then the R245fa steam enters the condenser 4 and is heated to return water of a heat supply network, the R245fa steam is changed into liquid from a steam state to release condensation heat, the liquid R245fa enters the throttle valve 6 and is subjected to temperature reduction and pressure reduction, and then the liquid R245fa enters the evaporator 5 and is heated by smoke gas to be changed into a steam state R245 fa. The return water of the heat supply network is sequentially heated by the condenser 8, the condenser 4 and the flue gas-water heat exchanger 7, and simultaneously the flue gas is sequentially cooled in the flue gas-water heat exchanger 7 and the evaporator 5.

Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims

The deep recovery flue gas waste heat gas boiler heating system is characterized by comprising a gas boiler (1), a steam turbine (2), a compressor (3), a condenser (4), an evaporator (5), a throttle valve (6), a flue gas-water heat exchanger (7), a condenser (8) and a circulating pump (9), wherein the boiler (1) is connected with the steam turbine (2) and the circulating pump (9), the steam turbine (2) is connected with the boiler (1), the condenser (8) and the compressor (3), the condenser (8) is connected with the steam turbine (2) and the circulating pump (9), the compressor (3) is connected with the steam turbine (2), the condenser (4) and the evaporator (5), the condenser (4) is connected with the compressor (3), the throttle valve (6), the condenser (8) and the flue gas-water heat exchanger (7), the flue gas-water heat exchanger (5) is connected with the compressor (3), the throttle valve (6) and the flue gas-water heat exchanger (7), the flue gas-water heat exchanger (7) is connected with the boiler (1), the flue gas-water heat exchanger (5) and the flue gas-water heat exchanger (5) are sequentially extracted from a high-temperature-high-water heat-recovery steam-recovery steam-generator (5), the high-recovery steam-.
2. The deep recycling flue gas waste heat gas boiler heating system of claim 1, wherein the system is composed of two circulation loops, are water circulation loops, are freon circulation loops, the water circulation loops are composed of a gas boiler (1), a steam turbine (2), a condenser (8) and a circulation pump, liquid water is heated by high-temperature flue gas combusted by gas in the gas boiler (1) and is changed into high-temperature high-pressure steam, the steam enters the steam turbine (2) to do work and is changed into low-temperature low-pressure exhaust steam, the exhaust steam enters the condenser (8) to be cooled by hot water return water and is changed into liquid water, the liquid water is sent to the gas boiler (1) through the circulation pump (9) to be circulated in a reciprocating manner, the freon circulation loops are composed of a compressor (3), a condenser (4), an evaporator (5) and a throttle valve (6), the compressor (3) is driven by the steam turbine (2) to realize that the compressed steam heats and boosts the temperature of the freon steam in the condenser (4) to be changed into liquid state, the liquid freon steam enters the throttle valve (6) to realize that the compressed steam is reduced in the temperature and is changed into the liquid freon steam in the condenser (5), the liquid freon steam return water, the liquid freon steam is changed into the liquid state, and is changed into the liquid freon steam heated.
3. The heating system of kinds of deep recovery flue gas waste heat gas-fired boilers, as claimed in claim 1, wherein the compressor (3) is driven by a rotor in the steam turbine (2) through a shaft.
4. The heating system of kinds of deep recovery flue gas waste heat gas-fired boilers, as claimed in claim 1, wherein the circulating medium in the compressor (3), condenser (4), evaporator (5) and throttle valve (6) is pure freon or a mixture of two freon media.
5. The heating system of the gas-fired boiler with the deep recovery of the flue gas waste heat according to claim 1, wherein the return water of the heat supply network sequentially passes through the condenser (8), the condenser (4) and the flue gas-water heat exchanger (7) to be heated and then leaves the system.