Coupling structure of gas power plant and LNG emergency gas source station

Abstract

The utility model discloses a coupling structure of a gas power plant and an LNG emergency gas source station. The coupling structure comprises the gas power plant and the LNG emergency gas source station. A pipeline for conveying steam to the waste heat boiler turbine by the waste heat boiler of the gas power plant is connected with the steam heater by conveying steam generated by waste heat of the three-way piece; a cooling medium obtaining heat in the condenser is conveyed to the LNG water bath vaporizer through a tee joint on a pipeline from the condenser for condensing steam exhausted by the waste heat boiler steam turbine to the corresponding circulating cooling water tank and the cooling tower; the LNG emergency gas source station comprises an LNG storage tank; lNG in the LNG storage tank is increased through the LNG booster pump, then is sequentially input into the LNG water bath vaporizer, the steam heater and the filtering, metering and pressure-regulating pry, and is input into the combustion chamber through a pipeline and a three-way valve arranged between the filtering, metering, heating and pressure-regulating pry and the combustion chamber of the gas power plant.

Description

Technical Field

[0001] This utility model relates to the field of gas-fired power plant construction technology, and in particular to the coupling structure of a gas-fired power plant and an LNG emergency gas source station. Background Technology

[0002] A gas-fired power plant uses natural gas as fuel and employs a circulating system consisting of a gas turbine, a generator, a waste heat boiler, and a steam turbine. It recovers the high-temperature exhaust gas from the gas turbine through the waste heat boiler, converts it into steam, and then injects the steam into the steam turbine to generate electricity. It can also supply steam to the outside world.

[0003] Gas turbines typically require a natural gas inlet pressure greater than 3.0 MPa and an inlet temperature greater than 30°C. In a typical gas-fired power plant system: pipeline natural gas (inlet pressure generally greater than 4.0 MPa) is filtered, metered, heated, and pressure-regulated to reach the temperature and pressure required by the gas turbine (e.g., pressure 3.0 MPa, temperature 30°C) before being sent to the combustion chamber of the gas turbine to mix and burn with air from the compressor. The combustion of the gas drives a generator to produce electricity. Some unburned natural gas enters a preheating boiler to produce steam. Part of the steam is sent out, and part is sent to the turbine to generate electricity. The condensate is cooled by circulating cooling water and then pressurized by a condensate pump before being sent to a waste heat boiler. The circulating cooling water is heated and then cooled in a cooling tower before being recycled.

[0004] To prevent pipeline natural gas failures from affecting gas supply security, gas-fired power plants are generally equipped with LNG emergency gas source stations, which can also provide natural gas for gas turbines.

[0005] like Figure 1 As shown, the specific structure of the LNG emergency gas source station in the gas-fired power plant is as follows:

[0006] LNG is unloaded from tank trucks and stored in LNG storage tanks. A portion of it is vaporized and heated in an LNG ambient temperature vaporizer, then pressure-regulated by a self-use gas skid before being sent to a hot water boiler to supply hot water to the water bath heater.

[0007] The gas turbine generally requires the natural gas inlet pressure to be greater than 3.0 MPa, and therefore a part of the LNG is boosted to 3.2 MPa by the LNG cryogenic pump and then is sent to the LNG high-pressure air temperature vaporizer for vaporization. Since the gas consumption of the gas power plant is large, the general gas consumption is 20-100 thousand cubic meters per hour, and the common scale of the high-pressure air temperature vaporizer is 5000 cubic meters per hour. The air temperature vaporizer is prone to frost formation during operation, which leads to a decrease in the vaporization capacity, and a plurality of groups of the air temperature vaporizer need to be set for switching use. Therefore, 8-40 air temperature vaporizers need to be set. The temperature of the natural gas after being vaporized by the air temperature vaporizer is greater than 5 DEG C of the air dew point temperature, and when the temperature of the natural gas out of the air temperature vaporizer is lower than -10 DEG C in winter, the natural gas needs to be heated to above 0 DEG C by the water bath vaporizer heater, and finally the natural gas is filtered, metered and stabilized to be supplied to the gas power plant. The natural gas to the gas power plant also needs to pass through the heating device of the power plant to be supplied to the gas turbine.

[0008] The LNG emergency gas source station of the gas power plant needs to set the hot water boiler room to heat the natural gas, and therefore the LNG emergency gas source station of the gas power plant has a large area and a large investment.

[0009] Since the LNG emergency gas source station of the gas power plant and the gas power plant are close to each other in construction location, even adjacent to each other in construction, the gas power plant supplies steam, and the LNG emergency gas source station needs heat source for vaporization and heating of the LNG.

[0010] Therefore, how to organically combine the gas power plant and the LNG emergency gas source station to reduce the cost and improve the efficiency becomes a technical problem to be solved by the person skilled in the art. Practical new type content

[0011] In view of the above defects of the prior art, the gas supply coupling structure of the gas power plant and the LNG emergency gas source station is provided, and the purpose is to realize the resource sharing and complementary advantages of the gas power plant and the LNG gas source station, and save the land and investment.

[0012] In order to achieve the above purpose, the coupling structure of the gas power plant and the LNG emergency gas source station is disclosed, which comprises the gas power plant and the LNG emergency gas source station.

[0013] The pipeline through which the waste heat boiler of the gas power plant delivers steam to the waste heat boiler turbine is connected to the steam heater through the tee piece waste heat generated steam;

[0014] The condenser which condenses the steam discharged from the waste heat boiler turbine is connected to the pipeline of the corresponding circulating cooling water pool and cooling tower, and the cooling medium which obtains heat in the condenser is delivered to the LNG water bath vaporizer through the tee piece;

[0015] The LNG emergency gas source station comprises an LNG storage tank.

[0016] The LNG in the LNG storage tank is sequentially input into the LNG water bath vaporizer, the steam heater and the filtering metering pressure stabilizer after being increased by the LNG booster pump, and is input into the combustion chamber through a pipeline and a three-way valve arranged between the filtering metering heating pressure stabilizer and the combustion chamber of the gas power plant.

[0017] Preferably, a flow regulating valve is arranged between the LNG booster pump and the LNG water bath vaporizer.

[0018] Preferably, a port capable of realizing steam external supply is formed on the pipeline from the waste heat boiler to the steam heater by arranging a three-way valve.

[0019] Preferably, the LNG water bath vaporizer is connected with the circulating cooling water pool and the cooling tower through a pipeline to input the cooling medium after heat release into the circulating cooling water pool and the cooling tower.

[0020] Preferably, the cooling medium is water; and the pipeline through which the LNG water bath vaporizer inputs the cooling medium is provided with a circulating water pump.

[0021] Preferably, a circulating pipeline is formed between the outlet of the condenser and the waste heat boiler through a pipeline, and a condensate pump is arranged in the pipeline between the condenser and the waste heat boiler.

[0022] Preferably, the waste heat boiler steam turbine drives a steam generator to generate power when the waste heat boiler steam turbine is running.

[0023] Preferably, the combustion chamber is connected with a gas turbine, and natural gas is combusted to drive the gas turbine; a port through which the gas turbine exhausts waste gas is connected with the waste heat boiler through a pipeline, and the waste heat in the waste gas is recovered by the waste heat boiler.

[0024] More preferably, the gas turbine drives a gas generator and a compressor to work, the gas generator generates power, and the compressor supplies air to the combustion chamber.

[0025] Preferably, the LNG storage tank is replenished with LNG by a tank car.

[0026] The present application has the following beneficial effects:

[0027] The present application couples the circulating water process, the steam process and the natural gas process in a system, and realizes overall optimization and improvement.

[0028] The present application only needs to use 1-2 tube-shell LNG water bath vaporizers to replace N groups of LNG high-pressure air temperature vaporizers, and the land occupation and cost are greatly reduced.

[0029] The present application directly uses the external supply steam of the power plant to heat the steam heater, and the self-use gas process and the boiler room configuration are omitted, the process is simplified, and the investment and land occupation are saved.

[0030] The utility model discloses utilize the waste heat of power plant circulating cooling water for gasification LNG, can reduce the water from 40 DEG C to 25 DEG C, and then backflow to the cooling water circulation system, serve cooling tower cooling.

[0031] The utility model discloses can produce the natural gas satisfying gas turbine requirement in advance before pipeline natural gas interruption, directly supply combustion chamber, connect pipeline gas, guarantee work continuous, stable, realize emergency function, further promote system operation stability.

[0032] The utility model discloses utilize the cold energy of LNG fully, improve the utilization efficiency of energy for gas power plant, utilize the circulating cooling water temperature of gas power plant fully, realize the utilization of maximum efficiency of energy for LNG emergency gas source station.

[0033] The application of the utility model makes the temperature of power plant circulating cooling water be reduced, and then enters the cooling water tower to carry out heat exchange, and the heat exchange capacity is improved, thereby achieving the effect of saving water resources.

[0034] The conception, specific structure and generated technical effect of the utility model will be further explained in combination with the drawings, so that the purpose, features and effect of the utility model can be fully understood. DRAWINGS

[0035] Figure 1 The structure schematic diagram of LNG emergency gas source station of gas power plant in prior art is shown.

[0036] Figure 2 The structure schematic diagram of one embodiment of the utility model is shown.

[0037] Figure 3 The structure schematic diagram of gas power plant in one embodiment of the utility model is shown. DETAILED DESCRIPTION

[0038] EMBODIMENT

[0039] As shown in Figure 2 and Figure 3 The coupling structure of gas power plant and LNG emergency gas source station includes gas power plant 1 and LNG emergency gas source station;

[0040] The pipeline of waste heat boiler 101 of gas power plant 1 to waste heat boiler steam turbine 102 is connected to steam heater 2 through three-way piece waste heat generated steam to steam heater 2;

[0041] The condenser 103 of waste heat boiler steam turbine 102 discharging steam is condensed to the pipeline of corresponding circulating cooling water pool and cooling tower 104, and the cooling medium of condenser 103 is transported to LNG water bath gasifier 3 through three-way.

[0042] The LNG emergency gas source station comprises an LNG storage tank 4;

[0043] The LNG in the LNG storage tank 4 is sequentially input into an LNG water bath vaporizer 3, a steam heater 2 and a filtering and metering pressure stabilizing pry 6 after being increased by an LNG booster pump 5, and is then input into a combustion chamber 106 through a pipeline and a three-way valve arranged between the filtering and metering heating pressure regulating pry 105 and the combustion chamber 106 of the gas power plant 1.

[0044] The utility model uses the LNG water bath vaporizer 3 to replace the LNG air temperature vaporizer, and gasifies the LNG by using the circulating cooling return water of the condenser 103 of the gas power plant 1 at 40 DEG C.

[0045] The LNG water bath vaporizer 3 is a tube shell heat exchanger, and the gasification scale can reach 500,000-1,000,000 cubic meters per hour, so that only 1-2 sets need to be arranged to meet the requirements.

[0046] The temperature of the LNG after being gasified is 0 DEG C, and the circulating cooling return water temperature is reduced to 25 DEG C and then returned to the circulating cooling pool and the cooling tower 104 of the gas power plant 1 for use of the condenser 103.

[0047] In actual application, two tube shell LNG water bath vaporizers 3 are used to replace 40 LNG high pressure air temperature vaporizers, the occupied area is reduced by 470 square meters, and the investment is reduced by 4.5 million yuan.

[0048] Secondly, the pipeline through which the waste heat boiler 101 of the gas power plant 1 delivers steam to the waste heat boiler steam turbine 102 is connected to the steam heater 2 through the three-way waste heat generated steam, the steam heater is directly supplied with steam from the gas power plant, the LNG after being gasified is heated to 30 DEG C and then supplied to the combustion chamber 106 of the power plant, the self-use gas flow process and the boiler room configuration are omitted, the process is simplified, the occupied area is reduced by 380 square meters, and the investment is reduced by 1 million yuan.

[0049] Finally, since there is a difference between the outlet natural gas temperature and the pipeline natural gas import temperature of the existing LNG emergency gas source station, the load of the power plant pipeline natural gas supporting heater does not necessarily meet the requirements of the outlet natural gas of the general LNG emergency gas source station, and even if it can meet the requirements, the steam circuit of the power plant needs to be continuously adjusted, and the operation is complex, the utility model heats the natural gas in the steam heater 2 to the pressure and temperature that meet the requirements of the gas turbine 109, the pipeline natural gas is connected to the power plant after being filtered, heated and pressure regulated, and directly enters the combustion chamber 106 of the gas turbine 109, and the load of the power plant pipeline natural gas supporting heater does not need to be considered, and the operation process is simpler.

[0050] In some embodiments, a flow regulating valve 7 is arranged between the LNG booster pump 5 and the LNG water bath vaporizer 3.

[0051] In some embodiments, a port 9 capable of realizing steam external supply is formed by setting a tee on the pipeline from the waste heat boiler 101 to the steam heater 2.

[0052] In some embodiments, the LNG water bath vaporizer 3 is connected to the circulating cooling water pool and the cooling tower 104 through a pipeline to input the heat-released cooling medium into the circulating cooling water pool and the cooling tower 104.

[0053] In some embodiments, the cooling medium is water; and the pipeline through which the LNG water bath vaporizer 3 inputs the cooling medium is provided with a circulating water pump 31.

[0054] In some embodiments, a circulation is formed by a pipeline between the outlet of the condenser 103 and the waste heat boiler 101, and a condensate pump 107 is arranged in the pipeline between the waste heat boiler 101.

[0055] In some embodiments, the waste heat boiler steam turbine 102 drives the steam turbine generator 108 to generate power when it operates.

[0056] In some embodiments, the combustion chamber 106 is connected to the gas turbine 109, natural gas is burned to drive the gas turbine 109; and a port through which the gas turbine 109 discharges exhaust gas is connected to the waste heat boiler 101 through a pipeline to recover the waste heat in the exhaust gas through the waste heat boiler 101.

[0057] In some embodiments, the gas turbine 109 drives the gas turbine generator 111 and the air compressor 110 to work, generates power through the gas turbine generator 111, and supplies air to the combustion chamber 106 through the air compressor 110.

[0058] In some embodiments, the LNG storage tank 4 is supplemented with LNG through the tank car unloading 8.

[0059] In actual application, in order to meet the requirements of the gas turbine, the natural gas needs to be adjusted to a specific pressure and temperature, and the outlet natural gas of the coupled LNG emergency gas source station has the functions of filtering, metering, pressure regulating and heating, can reasonably match the heating power and the natural gas flow in advance before the pipeline gas is interrupted, directly supply the combustion chamber, connect the pipeline gas, ensure the continuous and stable work, realize the emergency function, and further improve the system operation stability.

[0060] The application of the utility model realizes resource sharing and advantage complementation of the gas power plant and the LNG emergency gas source station, utilizes the cold energy of the LNG, the waste heat of the circulating cooling water and the heat energy of the steam, increases the benefit of the gas power plant, saves the energy, saves the land occupation of the LNG emergency gas source station, and reduces the investment.

[0061] The preferred embodiments of the present application are described in detail above. It should be understood that those skilled in the art can make many modifications and changes without creative labor based on the concept of the present application. Therefore, any technical solutions obtained by logical analysis, reasoning or limited experiments based on the existing technology within the concept of the present application shall be within the protection scope defined by the claims.

Claims

1. A coupling structure of a gas power plant and an LNG emergency gas source station; characterized in that, The gas power plant (1) and the LNG emergency gas source station are included; The pipeline through which the waste heat boiler (101) of the gas power plant (1) delivers steam to the waste heat boiler steam turbine (102) is connected to the steam heater (2) through a tee joint; The condenser (103) which condenses the steam discharged from the waste heat boiler steam turbine (102) is connected to the corresponding circulating cooling water pool and cooling tower (104) through a pipeline, and the cooling medium which obtains heat in the condenser (103) is delivered to the LNG water bath gasifier (3) through a tee joint; The LNG emergency gas source station includes an LNG storage tank (4); The LNG in the LNG storage tank (4) is increased by the LNG booster pump (5) and then sequentially input into the LNG water bath gasifier (3), the steam heater (2) and the filtering, metering and pressure stabilizing pry (6), and then input into the combustion chamber (106) through a pipeline and a tee joint valve arranged between the filtering, metering and heating pressure regulating pry (105) and the combustion chamber (106) in the gas power plant (1).

2. The coupling structure of a gas power plant and an LNG emergency gas source station according to claim 1, characterized in that, A flow regulating valve (7) is arranged between the LNG booster pump (5) and the LNG water bath gasifier (3).

3. The coupling structure of a gas power plant and an LNG emergency gas source station according to claim 1, characterized in that, A port (9) capable of realizing external steam supply is formed by arranging a tee joint on the pipeline from the waste heat boiler (101) to the steam heater (2).

4. The coupling structure of a gas power plant and an LNG emergency gas source station according to claim 1, characterized in that, The LNG water bath gasifier (3) is connected to the circulating cooling water pool and cooling tower (104) through a pipeline to input the cooling medium after heat release into the circulating cooling water pool and cooling tower (104).

5. The coupling structure of a gas power plant and an LNG emergency gas source station according to claim 1, characterized in that, The cooling medium is water; the pipeline through which the LNG water bath gasifier (3) inputs the cooling medium is provided with a circulating water pump (31).

6. The coupling structure of a gas power plant and an LNG emergency gas source station according to claim 1, characterized in that, A circulating loop is formed by a pipeline between the outlet of the condenser (103) and the waste heat boiler (101), and a condensate pump (107) is arranged in the pipeline between the condenser (103) and the waste heat boiler (101).

7. The coupling structure of a gas power plant and an LNG emergency gas source station according to claim 1, characterized in that, The waste heat boiler steam turbine (102) drives the steam turbine generator (108) to generate electricity when it operates.

8. The coupling structure of a gas power plant and an LNG emergency gas source station according to claim 1, characterized in that, The combustion chamber (106) is connected to the gas turbine (109), and natural gas is combusted to drive the gas turbine (109); the port through which the gas turbine (109) discharges exhaust gas is connected to the waste heat boiler (101) through a pipeline, and the waste heat boiler (101) recovers the waste heat in the exhaust gas.

9. The coupling structure of a gas power plant and an LNG emergency gas source station according to claim 8, characterized in that, The gas turbine (109) drives the gas engine generator (111) and the air compressor (110) to work, generates electricity through the gas engine generator (111), and supplies air to the combustion chamber (106) through the air compressor (110).

10. The coupling structure of a gas power plant and an LNG emergency gas source station according to claim 1, characterized in that, The LNG storage tank (4) is replenished with LNG through the tank car unloading (8).

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