A combined cycle cooling, heating and power system integrating fuel cells and solar energy

Abstract

The present invention relates to a combined cycle cooling, heating and power system integrating fuel cells and solar energy, belonging to the technical field of cooling, heating and power combined supply. The combined supply system includes: a solid oxide fuel cell subsystem; a solar thermal complementary gas-steam combined cycle subsystem, including a gas turbine subsystem and a steam cycle subsystem; and a double-effect absorption lithium bromide refrigeration subsystem. The gas turbine subsystem is connected to the solid oxide fuel cell subsystem and the steam cycle subsystem respectively; the steam cycle subsystem is also connected to the double-effect absorption lithium bromide refrigeration subsystem. The solid oxide fuel cell subsystem is capable of generating electricity and supplementary combustion, the solar thermal complementary gas-steam combined cycle subsystem is capable of generating electricity and providing heat load to the user side, and the double-effect absorption lithium bromide refrigeration subsystem is capable of providing cooling load to the user side, thereby reducing the energy loss of the system and improving the work capacity of the system while meeting the user's multiple energy needs of cooling, heating and electricity.

Description

Technical Field

[0001] The present invention relates to the technical field of solid oxide fuel cells and combined cooling, heating and power generation, and in particular to a combined cycle combined cooling, heating and power generation system integrating fuel cells and solar energy. Background Art

[0002] In recent years, to address economic development challenges caused by energy scarcity and environmental pollution, there has been a need to seek more efficient system coupling methods, focusing on improving system performance and reducing energy losses. This, combined with the introduction of renewable energy, has led to the rational construction of a distributed energy system with complementary multi-energy sources. Fossil fuels have long dominated the global energy mix. However, with the continued deterioration of issues such as excessive fossil fuel consumption and increasingly severe environmental pollution, the large-scale and efficient utilization of solar energy, the largest renewable energy resource, has become an inevitable requirement for adjusting the global energy mix and achieving sustainable development. Therefore, how to efficiently utilize solar energy, a renewable energy source, to improve system performance while simultaneously meeting users' diverse energy needs for cooling, heating, and electricity, remains a pressing technical challenge in this field. Summary of the Invention

[0003] The purpose of the present invention is to provide a combined cycle cooling, heating and power system integrating fuel cells and solar energy, so as to reduce the energy loss of the system and improve the work capacity of the system while meeting the user's multiple energy needs of cooling, heating and electricity.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A combined cycle cooling, heating, and power system integrating fuel cells and solar energy, comprising: a solid oxide fuel cell subsystem, a solar thermal complementary gas-steam combined cycle subsystem, and a double-effect absorption lithium bromide refrigeration subsystem; the solar thermal complementary gas-steam combined cycle subsystem comprises a gas turbine subsystem and a steam cycle subsystem; the gas turbine subsystem is connected to the solid oxide fuel cell subsystem and the steam cycle subsystem, respectively; the steam cycle subsystem is also connected to the double-effect absorption lithium bromide refrigeration subsystem;

[0006] The solid oxide fuel cell subsystem comprises: a gas mixer (101), a gas heat exchanger (102), a fuel cell anode (103), a gas separator (104), an air heat exchanger (105), a fuel cell cathode (106), a DC / AC converter (107) and a fuel cell afterburner (108); the outlet of the gas mixer (101) is connected to the first inlet of the gas heat exchanger (102); the first outlet of the gas heat exchanger (102) is connected to the inlet of the fuel cell anode (103); the outlet of the fuel cell anode (103) is connected to the inlet of the gas separator (104); the first outlet of the gas separator (104) is connected to the first inlet of the gas mixer (101). The second outlet of the gas separator (104) is connected to the first inlet of the fuel cell afterburner (108); the first outlet of the air heat exchanger (105) is connected to the inlet of the fuel cell cathode (106); the outlet of the fuel cell cathode (106) is connected to the second inlet of the fuel cell afterburner (108); the outlet of the fuel cell outputs electricity through the DC-AC converter (107); the outlet of the fuel cell afterburner (108) is connected to the second inlet of the gas heat exchanger (102); the second outlet of the gas heat exchanger (102) is connected to the first inlet of the air heat exchanger (105); and the second outlet of the air heat exchanger (105) is connected to the gas turbine subsystem.

[0007] Optionally, the fuel cell is a solid oxide fuel cell.

[0008] Optionally, methane is introduced into the second inlet of the gas mixer (101); carbon dioxide is introduced into the third inlet of the gas mixer (101); and air is introduced into the second inlet of the air heat exchanger (105).

[0009] Optionally, the gas turbine subsystem includes: a compressor (201), a combustion chamber (202), a gas turbine (203), a first generator (204) and a flue gas mixer (205);

[0010] The compressor (201) is connected to the gas turbine (203) through the combustion chamber (202); the compressor (201), the gas turbine (202) and the first generator (204) are coaxially connected, and electrical output is performed through the first generator (204); the second outlet of the air heat exchanger (105) is connected to the first inlet of the flue gas mixer (205); and the outlet of the gas turbine (203) is connected to the second inlet of the flue gas mixer (205).

[0011] Optionally, air is introduced into the inlet of the compressor (201); and methane is introduced into the inlet of the combustion chamber (202).

[0012] Optionally, the steam cycle subsystem includes: a waste heat boiler, a high-pressure cylinder of a steam turbine (306), an intermediate-pressure cylinder of a steam turbine (307), a low-pressure cylinder of a steam turbine (308), a second generator (309), a feed water heat exchanger (310), a condenser (311), a low-pressure feed water pump (312), an intermediate-pressure feed water pump (313), a high-pressure feed water pump (314), a first solar collector (316), a first feed water mixer (317), a second solar collector (318), and a second feed water mixer (319). ); the waste heat boiler comprises a first heat exchanger group (301), a first-stage high-pressure economizer (302), a second heat exchanger group (303), a second-stage high-pressure economizer (304) and a third heat exchanger group (305); the first heat exchanger group (301) is composed of a low-pressure economizer and a low-pressure evaporator; the second heat exchanger group (303) is composed of a medium-pressure economizer, a medium-pressure evaporator and a low-pressure superheater; the third heat exchanger group (305) is composed of a medium-pressure superheater, a high-pressure evaporator, a reheater and a high-pressure superheater;

[0013] The outlet of the flue gas mixer (205) is connected to the inlet of the waste heat boiler; the outlet of the high-pressure superheater of the third heat exchanger group (305) is connected to the first inlet of the high-pressure cylinder (306) of the steam turbine; the outlet of the high-pressure cylinder (306) of the steam turbine is connected to the inlet of the reheater of the third heat exchanger group (305); the outlet of the reheater of the third heat exchanger group (305) is connected to the inlet of the intermediate-pressure cylinder (307) of the steam turbine; the first outlet of the intermediate-pressure cylinder (307) of the steam turbine is connected to the inlet of the low-pressure cylinder (308) of the steam turbine, and the second outlet of the intermediate-pressure cylinder (307) of the steam turbine is connected to the first inlet of the feedwater heat exchanger (310); the second inlet of the feedwater heat exchanger (310) is connected to the inlet of the intermediate-pressure cylinder (307) of the steam turbine. Normal temperature water; the first outlet of the feedwater heat exchanger (310) is connected to the inlet of the low-pressure feedwater pump (312); the second outlet of the feedwater heat exchanger (310) outputs heat; the high-pressure cylinder (306) of the steam turbine, the intermediate-pressure cylinder (307) of the steam turbine, the low-pressure cylinder (308) of the steam turbine, and the second generator (309) are coaxially connected, and electrical output is performed through the second generator (209); the outlet of the low-pressure cylinder (308) of the steam turbine is connected to the inlet of the condenser (311); the outlet of the condenser (311) is connected to the inlet of the low-pressure feedwater pump (312); the outlet of the low-pressure feedwater pump (312) is connected to the inlet of the low-pressure economizer of the first heat exchanger group (301);

[0014] The low-pressure superheater outlet of the second heat exchanger group (303) is connected to the inlet of the low-pressure cylinder (308) of the steam turbine; the first outlet of the low-pressure economizer of the first heat exchanger group (301) is connected to the inlet of the high-pressure feed water pump (314); the first outlet of the high-pressure feed water pump (314) is connected to the first inlet of the first-stage high-pressure economizer (302); the second outlet of the low-pressure economizer of the first heat exchanger group (301) is connected to the inlet of the medium-pressure economizer of the second heat exchanger group (303) through the medium-pressure feed water pump (313);

[0015] The second outlet of the high-pressure feed water pump (314) is connected to the inlet of the first solar thermal collector (316); the outlet of the first solar thermal collector (316) is connected to the first inlet of the first feed water mixer (317); the second outlet of the first-stage high-pressure economizer (302) is connected to the second inlet of the first feed water mixer (317); the first outlet of the first feed water mixer (317) is connected to the inlet of the second solar thermal collector (318); the outlet of the second solar thermal collector (318) is connected to the first inlet of the second feed water mixer (319); the second outlet of the first feed water mixer (317) is connected to the second inlet of the second-stage high-pressure economizer (304); the second outlet of the second-stage high-pressure economizer (304) is connected to the second inlet of the second feed water mixer (319); the outlet of the second feed water mixer (319) is connected to the inlet of the high-pressure evaporator of the third heat exchanger group (305).

[0016] Optionally, the first solar thermal collector (316) and the second solar thermal collector (318) are both trough solar thermal collectors.

[0017] Optionally, the double-effect absorption lithium bromide refrigeration subsystem comprises: a double-effect absorption lithium bromide refrigerator (315);

[0018] The first outlet of the low-pressure evaporator of the first heat exchanger group (301) is connected to the first inlet of the double-effect absorption type lithium bromide refrigerator (315); the first outlet of the double-effect absorption type lithium bromide refrigerator (315) is connected to the second inlet of the low-pressure economizer of the first heat exchanger group (301); the second inlet of the double-effect absorption type lithium bromide refrigerator (315) is connected to the chilled water inlet; the second outlet of the double-effect absorption type lithium bromide refrigerator (315) outputs cold water.

[0019] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0020] The present invention provides a combined cycle cooling, heating, and power system integrating fuel cells and solar energy, comprising: a solid oxide fuel cell subsystem, a solar thermal complementary gas-steam combined cycle subsystem, and a double-effect absorption lithium bromide refrigeration subsystem. The solar thermal complementary gas-steam combined cycle subsystem includes a gas turbine subsystem and a steam cycle subsystem. The gas turbine subsystem is connected to the solid oxide fuel cell subsystem and the steam cycle subsystem, respectively. The steam cycle subsystem is also connected to the double-effect absorption lithium bromide refrigeration subsystem. The solid oxide fuel cell subsystem is capable of both power generation and supplementary combustion. The fuel cell is used for power generation, and the high-temperature exhaust gas emitted by the fuel cell is then used as supplementary combustion gas. The supplementary combustion gas is mixed with the exhaust gas of the gas turbine subsystem to drive the steam cycle subsystem. This effectively utilizes the waste heat generated by the high-temperature fuel cell and reduces energy loss in the system. The solar thermal complementary gas-steam combined cycle subsystem is capable of power generation and providing heat load to users, while the double-effect absorption lithium bromide refrigeration subsystem is capable of providing cooling load to users. This reduces energy loss and improves the system's work capacity while meeting users' multiple energy needs for cooling, heating, and electricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 The figure is a schematic structural diagram of a combined cycle cooling, heating and power system integrating fuel cells and solar energy according to the present invention. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] The purpose of the present invention is to provide a combined cycle cooling, heating and power system integrating fuel cells and solar energy, so as to reduce the energy loss of the system and improve the work capacity of the system while meeting the user's multiple energy needs of cooling, heating and electricity.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 This is a structural diagram of a combined cycle cooling, heating and power system integrating fuel cells and solar energy according to the present invention. Figure 1 As shown, the integrated fuel cell and solar combined cycle cooling, heating, and power system (hereinafter referred to as the combined power system) includes: a solid oxide fuel cell subsystem, a solar thermal complementary gas-steam combined cycle subsystem, and a double-effect absorption lithium bromide refrigeration subsystem, each of which is connected by pipes and valves. The solar thermal complementary gas-steam combined cycle subsystem includes a gas turbine subsystem and a steam cycle subsystem; the gas turbine subsystem is connected to the solid oxide fuel cell subsystem and the steam cycle subsystem respectively; the steam cycle subsystem is also connected to the double-effect absorption lithium bromide refrigeration subsystem.

[0027] The solid oxide fuel cell subsystem is used for power generation and supplementary combustion. A solid oxide fuel cell (SOFC) is used for power generation. The high-temperature exhaust gas emitted by the fuel cell is then used as supplementary combustion gas. The high-temperature exhaust gas is mixed with the exhaust gas of the gas turbine subsystem in the flue gas mixer 205 to jointly drive the steam cycle subsystem in the solar thermal complementary gas-steam combined cycle subsystem.

[0028] The solar thermal complementary gas-steam combined cycle subsystem is used to generate electricity and provide heat load to users. The gas turbine subsystem in the solar thermal complementary gas-steam combined cycle subsystem is primarily used for power generation, and the exhaust gas from the gas turbine subsystem drives the steam cycle subsystem in the solar thermal complementary gas-steam combined cycle subsystem. Solar collectors are used to partially replace the heat load of the first-stage high-pressure economizer and the second-stage high-pressure economizer in the waste heat boiler. When the solar radiation intensity reaches a certain level, the solar collectors begin to operate, increasing the circulating mass in the waste heat boiler and thereby increasing the power generation of the steam turbine. Simultaneously, this system extracts steam from the exhaust of the intermediate-pressure cylinder of the steam turbine in the waste heat boiler to heat domestic hot water, which is then output to users.

[0029] The double-effect absorption lithium bromide refrigeration subsystem is used to provide cooling load to the user side.

[0030] Specifically, see Figure 1 The solid oxide fuel cell subsystem includes: a gas mixer 101, a gas heat exchanger 102, a fuel cell anode 103, a gas separator 104, an air heat exchanger 105, a fuel cell cathode 106, a DC-AC converter 107, and a fuel cell afterburner 108. In practical applications, the fuel cell is a solid oxide fuel cell.

[0031] The second inlet of the gas mixer 101 is connected to methane; the third inlet of the gas mixer 101 is connected to carbon dioxide; the outlet of the gas mixer 101 is connected to the first inlet of the gas heat exchanger 102; the first outlet of the gas heat exchanger 102 is connected to the inlet of the fuel cell anode 103; the outlet of the fuel cell anode 103 is connected to the inlet of the gas separator 104; the first outlet of the gas separator 104 is connected to the first inlet of the gas mixer 101, and the second outlet of the gas separator 104 is connected to the first inlet of the fuel cell afterburner 108; the air exchanger 102 is connected to the first inlet of the gas mixer 101, and the second outlet of the gas separator 104 is connected to the first inlet of the fuel cell afterburner 108; The first outlet of the heat exchanger 105 is connected to the inlet of the fuel cell cathode 106; the outlet of the fuel cell cathode 106 is connected to the second inlet of the fuel cell afterburner 108; the outlet of the fuel cell outputs electricity through the DC-AC converter 107; the outlet of the fuel cell afterburner 108 is connected to the second inlet of the gas heat exchanger 102; the second outlet of the gas heat exchanger 102 is connected to the first inlet of the air heat exchanger 105; air is introduced into the second inlet of the air heat exchanger 105; the second outlet of the air heat exchanger 105 is connected to the flue gas mixer 205 of the gas turbine subsystem.

[0032] The high-temperature fuel cell in the solid oxide fuel cell subsystem features clean and efficient operation, with a theoretical power generation efficiency exceeding 50%. The exhaust gas from the cell is hot, making it highly valuable and easily integrated with traditional power systems. Furthermore, the solid oxide fuel cell uses solid ceramics as the electrolyte, cathode, and anode materials, which avoids problems such as electrolyte loss and thermal corrosion. Solid oxide fuel cells also offer advantages such as efficient power generation, clean operation, and flexible fuel utilization.

[0033] The solar thermal complementary gas-steam combined cycle subsystem introduces solar energy into a highly efficient combined cycle system, thereby improving the photoelectric conversion efficiency of solar energy, saving costs, and reducing fossil energy consumption.

[0034] See also Figure 1 The gas turbine subsystem in the solar thermal complementary gas-steam combined cycle subsystem includes: a compressor 201, a combustion chamber 202, a gas turbine 203, a first generator 204 and a flue gas mixer 205.

[0035] The compressor 201 is connected to the gas turbine 203 through the combustion chamber 202. Air is introduced into the inlet of the compressor 201, while methane is introduced into the inlet of the combustion chamber 202. The compressor 201, the gas turbine 202, and the first generator 204 are coaxially connected, and electrical output, i.e., electricity generation, is generated through the first generator 204. The second outlet of the air heat exchanger 105 is connected to the first inlet of the flue gas mixer 205; the outlet of the gas turbine 203 is connected to the second inlet of the flue gas mixer 205.

[0036] The steam cycle subsystem in the solar thermal complementary gas-steam combined cycle subsystem includes: a waste heat boiler (which includes a first heat exchanger group 301, a first-stage high-pressure economizer 302, a second heat exchanger group 303, a second-stage high-pressure economizer 304, and a third heat exchanger group 305), a steam turbine high-pressure cylinder 306, a steam turbine medium-pressure cylinder 307, a steam turbine low-pressure cylinder 308, a second generator 309, a feed water heat exchanger 310, a condenser 311, a low-pressure feed water pump 312, a medium-pressure feed water pump 313, a high-pressure feed water pump 314, a first solar collector 316, a first feed water mixer 317, a second solar collector 318, and a second feed water mixer 319. The first heat exchanger group 301 consists of a low-pressure economizer and a low-pressure evaporator; the second heat exchanger group 303 consists of an intermediate-pressure economizer, an intermediate-pressure evaporator, and a low-pressure superheater; and the third heat exchanger group 305 consists of an intermediate-pressure superheater, a high-pressure evaporator, a reheater, and a high-pressure superheater. In practical applications, the first heat exchanger group 301, the first-stage high-pressure economizer 302, the second heat exchanger group 303, the second-stage high-pressure economizer 304, and the third heat exchanger group 305 are typically components of a waste heat boiler.

[0037] The outlet of the flue gas mixer (205) is connected to the inlet of the waste heat boiler; water, a steam-water mixture, or steam flows through the waste heat boiler. The outlet of the high-pressure superheater of the third heat exchanger group 305 is connected to the first inlet of the high-pressure cylinder 306 of the steam turbine; the outlet of the high-pressure cylinder 306 of the steam turbine is connected to the inlet of the reheater of the third heat exchanger group 305; the outlet of the reheater of the third heat exchanger group 305 is connected to the inlet of the intermediate-pressure cylinder 307 of the steam turbine; the first outlet of the intermediate-pressure cylinder 307 of the steam turbine is connected to the inlet of the low-pressure cylinder 308 of the steam turbine, and the second outlet of the intermediate-pressure cylinder 307 of the steam turbine is connected to the first inlet of the feedwater heat exchanger 310; the second inlet of the feedwater heat exchanger 310 is connected to normal temperature water; the first outlet of the feedwater heat exchanger 310 is connected to the inlet of the low-pressure feedwater pump 312. The second outlet of the feedwater heat exchanger 310 outputs heat, generating hot water as a heat load. The steam turbine high-pressure cylinder 306, the steam turbine intermediate-pressure cylinder 307, the steam turbine low-pressure cylinder 308, and the second generator 309 are coaxially connected, with electricity output via the second generator 209. The outlet of the steam turbine low-pressure cylinder 308 is connected to the inlet of the condenser 311; the outlet of the condenser 311 is connected to the inlet of the low-pressure feedwater pump 312; and the outlet of the low-pressure feedwater pump 312 is connected to the inlet of the low-pressure economizer of the first heat exchanger group 301.

[0038] The low-pressure superheater outlet of the second heat exchanger group 303 is connected to the inlet of the low-pressure cylinder 308 of the turbine; the first outlet of the low-pressure economizer of the first heat exchanger group 301 is connected to the inlet of the high-pressure feed water pump 314; the first outlet of the high-pressure feed water pump 314 is connected to the first inlet of the first-stage high-pressure economizer 302; the second outlet of the low-pressure economizer of the first heat exchanger group 301 is connected to the medium-pressure economizer inlet of the second heat exchanger group 303 through the medium-pressure feed water pump 313.

[0039] The second outlet of the high-pressure feed water pump 314 is connected to the inlet of the first solar collector 316; the outlet of the first solar collector 316 is connected to the first inlet of the first feed water mixer 317; the second outlet of the first-stage high-pressure economizer 302 is connected to the second inlet of the first feed water mixer 317; the first outlet of the first feed water mixer 317 is connected to the inlet of the second solar collector 318; the outlet of the second solar collector 318 is connected to the first inlet of the second feed water mixer 319; the second outlet of the first feed water mixer 317 is connected to the second inlet of the second-stage high-pressure economizer 304; the second outlet of the second-stage high-pressure economizer 304 is connected to the second inlet of the second feed water mixer 319; the outlet of the second feed water mixer 319 is connected to the high-pressure evaporator inlet of the third heat exchanger group 305.

[0040] The first heat exchanger group 301, the first-stage high-pressure economizer 302, the second heat exchanger group 303, the second-stage high-pressure economizer 304, and the third heat exchanger group 305 are arranged in a certain position, and the flue gas flows from the outlet of the flue gas mixer 205 through the first heat exchanger group 301, the first-stage high-pressure economizer 302 and the second heat exchanger group 303. Figure 1 The arrows between the first heat exchanger group 301, the first-stage high-pressure economizer 302, the second heat exchanger group 303, the second-stage high-pressure economizer 304, and the third heat exchanger group 305 indicate the direction of the flue gas. The heat exchangers are composed of pipes, and steam and water flow in the pipes, and the flue gas flows through the outer surface of the pipes. The outlet of the steam turbine high-pressure cylinder (306) is connected to the inlet of the reheater of the third heat exchanger group (305).

[0041] The first solar thermal collector 316 and the second solar thermal collector 318 are both trough solar thermal collectors.

[0042] See also Figure 1 The double-effect absorption lithium bromide refrigeration subsystem includes a double-effect absorption lithium bromide refrigerator 315. The first outlet of the low-pressure evaporator of the first heat exchanger group 301 is connected to the first inlet of the double-effect absorption lithium bromide refrigerator 315; the first outlet of the double-effect absorption lithium bromide refrigerator 315 is connected to the second outlet of the low-pressure economizer of the first heat exchanger group 301; the second inlet of the double-effect absorption lithium bromide refrigerator 315 is connected to the chilled water inlet; and the second outlet of the double-effect absorption lithium bromide refrigerator 315 outputs cold water, i.e., generates chilled water outlet as the cooling load.

[0043] See also Figure 1 The working process of the combined cycle cooling, heating and power supply system integrating fuel cells and solar energy of the present invention is described as follows.

[0044] Methane is fed into the gas mixer 101 of the solid oxide fuel cell subsystem and the combustion chamber 202 of the gas turbine subsystem. The solid oxide fuel cell undergoes an electrochemical reaction, generating electricity. Methane burns in the combustion chamber 202 of the gas turbine subsystem, and the exhaust from combustion chamber 202 drives the gas turbine 203 to generate electricity, which is then output by the first generator 204. The exhaust from the solid oxide fuel cell and the exhaust from gas turbine 203 mix and then drive the steam cycle subsystem in the solar thermal complementary gas-steam combined cycle subsystem. In the steam cycle subsystem, the waste heat boiler is used as the heating surface carrier, and the first and second solar collectors 316 and 318 are used to replace part of the heat load of the first-stage high-pressure economizer 302 and the second-stage high-pressure economizer 304 in the waste heat boiler. When the solar radiation intensity reaches a certain level, the solar collectors 316 and 318 start to work, and the circulating work mass in the waste heat boiler increases, thereby increasing the power generation of the turbines 306, 307, and 308; at the same time, this combined power supply system extracts steam from the exhaust of the first heat exchanger group (also called the low-pressure steam drum) 301 in the waste heat boiler and the steam exhaust of the intermediate-pressure cylinder 307 of the steam turbine to drive the double-effect absorption lithium bromide refrigerator 315 to work and heat domestic hot water, and outputs cooling load (chilled water outlet) and heating load (hot water) to the user side.

[0045] Specifically, when the combined supply system operates under a certain solar radiation intensity, the water supply at the outlet of the high-pressure water supply pump 314 is divided into two lines. In one line, the water supply at the outlet of the high-pressure water supply pump 314 enters the first solar collector 316 to absorb solar thermal energy. When the outlet water supply temperature of the first solar collector 316 is the same as the outlet water supply temperature of the first-stage high-pressure economizer 302, the outlet water supply of the first solar collector 316 and the outlet water supply of the first-stage high-pressure economizer 302 enter the first water supply mixer 317 for mixing. The water supply at the outlet of the first water supply mixer 317 is divided into two lines. In one line, the water supply at the outlet of the first water supply mixer 317 enters the second solar collector 318 to absorb solar thermal energy. When the water supply temperature at the outlet of the second solar collector 318 is the same as the water supply temperature at the outlet of the second-stage high-pressure economizer 304, the water supply at the outlet of the second solar collector 318 and the water supply at the outlet of the second-stage high-pressure economizer 304 enter the second water supply mixer 319 and are mixed before entering the high-pressure evaporator of the third heat exchanger group 305 composed of a medium-pressure superheater, a high-pressure evaporator, a reheater and a high-pressure superheater.

[0046] When the solar radiation intensity is insufficient, the combined power supply system maintains normal operation by burning methane. The fuel cell, gas turbine 203 and steam turbine (including the high-pressure cylinder 306, the intermediate-pressure cylinder 307 and the low-pressure cylinder 308 of the steam turbine) generate electricity normally. At the same time, the double-effect absorption lithium bromide refrigerator 315 and the feed water heat exchanger 310 provide cooling load and heat domestic hot water to the user side.

[0047] The present invention discloses a combined cycle cooling, heating and power system integrating fuel cells and solar energy. The combined system includes a solid oxide fuel cell (SOFC) subsystem, a solar thermal complementary gas steam combined cycle (ISCC) subsystem and a double-effect absorption lithium bromide refrigeration subsystem. The combined system first uses the high-temperature exhaust gas generated by the solid oxide fuel cell to preheat the air entering the fuel cell cathode, and then mixes it with the exhaust gas of the gas turbine subsystem and enters the waste heat boiler together; the waste heat boiler is used as the waste heat recovery carrier, and solar energy is used to replace part of the heat load of the first-stage high-pressure economizer and the second-stage high-pressure economizer in the waste heat boiler, thereby increasing the work capacity of the bottom cycle. In order to fully meet the user's cooling and heating load requirements, the combined system extracts part of the steam from the low-pressure drum of the waste heat boiler, and uses this steam to drive the double-effect absorption lithium bromide refrigeration system. In addition, the combined system extracts part of the steam at the exhaust of the intermediate-pressure cylinder and uses this steam to heat domestic hot water. Therefore, the combined power supply system provided by the present invention can effectively utilize the waste heat generated by high-temperature fuel cells to reduce energy losses in the system while meeting the user's various energy needs for cooling, heating, and electricity; and efficiently utilize renewable energy - solar energy to improve the system's work capacity.

[0048] The following is a specific example to illustrate the technical effects of the cogeneration system provided by the present invention. In this example, the fuel used is natural gas transmitted from the West to the East, and the weather data is a typical day in Lhasa. Table 1 lists the basic data for thermodynamic analysis of the cogeneration system.

[0049] Table 1 Basic data of thermodynamic analysis of cogeneration system

[0050]

[0051] As shown in Table 1, when the combined power generation system is operated under stable working conditions on a typical day in Lhasa, its energy efficiency is 61.9% when considering the solar heat input. The efficiency is 52.61%.

[0052] The present invention discloses a combined cycle cooling, heating and power system integrating fuel cells and solar energy. In response to the current situation where traditional cogeneration systems lack thermodynamic advantages, a method of coupling high-temperature solid oxide fuel cells in the system is proposed. Since the exhaust temperature of the fuel cell is comparable to that of the gas turbine, the two are mixed and then passed to the waste heat boiler to ensure the cascade utilization of energy. This not only effectively utilizes the high-temperature waste heat of the solid oxide fuel cell, but also reduces energy losses in the system. The combined supply system has a reasonable structure coupled with a trough-type solar collector, which uses the solar collector to replace part of the heat load of the waste heat boiler, thereby improving the flue gas utilization rate of the waste heat boiler, increasing the power generation of the steam cycle subsystem, and further improving the work capacity of the system. Therefore, compared with traditional integration methods, the combined supply system provided by the present invention has significant thermodynamic advantages.

[0053] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0054] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the control method and its core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A combined cycle cooling, heating and power system integrating fuel cells and solar energy, characterized in that: include: A solid oxide fuel cell subsystem, a solar thermal complementary gas-steam combined cycle subsystem, and a double-effect absorption lithium bromide refrigeration subsystem; the solar thermal complementary gas-steam combined cycle subsystem includes a gas turbine subsystem and a steam cycle subsystem; the gas turbine subsystem is connected to the solid oxide fuel cell subsystem and the steam cycle subsystem respectively; the steam cycle subsystem is also connected to the double-effect absorption lithium bromide refrigeration subsystem; The solid oxide fuel cell subsystem includes: a gas mixer, a gas heat exchanger, a fuel cell anode, a gas separator, an air heat exchanger, a fuel cell cathode, a DC-AC converter and a fuel cell afterburner; the outlet of the gas mixer is connected to the first inlet of the gas heat exchanger; the first outlet of the gas heat exchanger is connected to the inlet of the fuel cell anode; the outlet of the fuel cell anode is connected to the inlet of the gas separator; the first outlet of the gas separator is connected to the first inlet of the gas mixer, and the second outlet of the gas separator is connected to the first inlet of the fuel cell afterburner; the first outlet of the air heat exchanger is connected to the inlet of the fuel cell cathode; the outlet of the fuel cell cathode is connected to the second inlet of the fuel cell afterburner; the outlet of the fuel cell outputs electricity through the DC-AC converter; the outlet of the fuel cell afterburner is connected to the second inlet of the gas heat exchanger; the second outlet of the gas heat exchanger is connected to the first inlet of the air heat exchanger; the second outlet of the air heat exchanger is connected to the gas turbine subsystem; The second inlet of the gas mixer is fed with methane; the third inlet of the gas mixer is fed with carbon dioxide; the second inlet of the air heat exchanger is fed with air; The gas turbine subsystem includes: a compressor, a combustion chamber, a gas turbine, a first generator and a flue gas mixer; The compressor is connected to the gas turbine through the combustion chamber; the compressor, the gas turbine and the first generator are coaxially connected, and electrical output is generated through the first generator; the second outlet of the air heat exchanger is connected to the first inlet of the flue gas mixer; the outlet of the gas turbine is connected to the second inlet of the flue gas mixer; The steam cycle subsystem includes: a waste heat boiler, a high-pressure cylinder of a steam turbine, an intermediate-pressure cylinder of a steam turbine, a low-pressure cylinder of a steam turbine, a second generator, a feedwater heat exchanger, a condenser, a low-pressure feedwater pump, an intermediate-pressure feedwater pump, a high-pressure feedwater pump, a first solar collector, a first feedwater mixer, a second solar collector, and a second feedwater mixer; the waste heat boiler includes a first heat exchanger group, a first-stage high-pressure economizer, a second heat exchanger group, a second-stage high-pressure economizer, and a third heat exchanger group; the first heat exchanger group consists of a low-pressure economizer and a low-pressure evaporator; the second heat exchanger group consists of an intermediate-pressure economizer, an intermediate-pressure evaporator, and a low-pressure superheater; the third heat exchanger group consists of an intermediate-pressure superheater, a high-pressure evaporator, a reheater, and a high-pressure superheater; The outlet of the flue gas mixer is connected to the inlet of the waste heat boiler; the outlet of the high-pressure superheater of the third heat exchanger group is connected to the first inlet of the high-pressure cylinder of the steam turbine; the outlet of the high-pressure cylinder of the steam turbine is connected to the inlet of the reheater of the third heat exchanger group; the outlet of the reheater of the third heat exchanger group is connected to the inlet of the intermediate-pressure cylinder of the steam turbine; the first outlet of the intermediate-pressure cylinder of the steam turbine is connected to the inlet of the low-pressure cylinder of the steam turbine, and the second outlet of the intermediate-pressure cylinder of the steam turbine is connected to the first inlet of the feedwater heat exchanger; the second outlet of the feedwater heat exchanger is connected to the first inlet of the feedwater heat exchanger The inlet of the feedwater heat exchanger is connected to normal temperature water; the first outlet of the feedwater heat exchanger is connected to the inlet of the low-pressure feedwater pump; the second outlet of the feedwater heat exchanger is used for heat output; the high-pressure cylinder of the steam turbine, the intermediate-pressure cylinder of the steam turbine, the low-pressure cylinder of the steam turbine and the second generator are coaxially connected, and electricity is output through the second generator; the outlet of the low-pressure cylinder of the steam turbine is connected to the inlet of the condenser; the outlet of the condenser is connected to the inlet of the low-pressure feedwater pump; the outlet of the low-pressure feedwater pump is connected to the inlet of the low-pressure economizer of the first heat exchanger group; The low-pressure superheater outlet of the second heat exchanger group is connected to the inlet of the low-pressure cylinder of the steam turbine; the first outlet of the low-pressure economizer of the first heat exchanger group is connected to the inlet of the high-pressure feed water pump; the first outlet of the high-pressure feed water pump is connected to the first inlet of the first-stage high-pressure economizer; the second outlet of the low-pressure economizer of the first heat exchanger group is connected to the medium-pressure economizer inlet of the second heat exchanger group through the medium-pressure feed water pump; The second outlet of the high-pressure feed water pump is connected to the inlet of the first solar collector; the outlet of the first solar collector is connected to the first inlet of the first feed water mixer; the second outlet of the first-stage high-pressure economizer is connected to the second inlet of the first feed water mixer; the first outlet of the first feed water mixer is connected to the inlet of the second solar collector; the outlet of the second solar collector is connected to the first inlet of the second feed water mixer; the second outlet of the first feed water mixer is connected to the second inlet of the second-stage high-pressure economizer; the second outlet of the second-stage high-pressure economizer is connected to the second inlet of the second feed water mixer; the outlet of the second feed water mixer is connected to the inlet of the high-pressure evaporator of the third heat exchanger group.

2. The combined cycle cooling, heating and power system integrating fuel cells and solar energy according to claim 1 is characterized in that: Air is introduced into the inlet of the compressor; methane is introduced into the inlet of the combustion chamber.

3. The combined cycle cooling, heating and power system integrating fuel cells and solar energy according to claim 1 is characterized in that: The first solar thermal collector and the second solar thermal collector are both trough solar thermal collectors.

4. The combined cycle cooling, heating and power system integrating fuel cells and solar energy according to claim 1, characterized in that: The double-effect absorption lithium bromide refrigeration subsystem includes: a double-effect absorption lithium bromide refrigerator; The first path in the low-pressure evaporator outlet of the first heat exchanger group is connected to the first inlet of the double-effect absorption lithium bromide refrigerator; the first outlet of the double-effect absorption lithium bromide refrigerator is connected to the second path in the low-pressure economizer inlet of the first heat exchanger group; the second inlet of the double-effect absorption lithium bromide refrigerator is connected to the chilled water inlet; the second outlet of the double-effect absorption lithium bromide refrigerator is used for cold output.

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