Combined cooling heating and power system based on SOFC hybrid power

Abstract

The invention discloses a combined cooling heating and power system based on SOFC (solid oxide fuel cell) hybrid power, which belongs to the technical field of hybrid power generation and comprises a solid oxide fuel cell, a vortex internal combustion engine, a homogeneous compression ignition internal combustion engine, an absorption refrigerator, a heat exchange module and a mixer. The cathode of the solid oxide fuel cell receives air and exhausts cathode tail gas, and the cathode tail gas is cooled and then sent to the absorption refrigerator to obtain chilled water; the anode of the solid oxide fuel cell receives fuel and discharges anode tail gas, the anode tail gas is heated and then sent to the homogeneous compression ignition internal combustion engine and the vortex internal combustion engine for combustion, and smoke of the homogeneous compression ignition internal combustion engine and the vortex internal combustion engine is mixed and then exchanges heat with the hot water circulation pipeline to obtain hot water. Ignition of a spark plug of the vortex internal combustion engine can accurately control the combustion time, and the problem that the combustion starting time of a homogeneous compression ignition internal combustion engine is difficult to control is solved; the power and hot water output of the internal combustion engine are flexibly controlled by adjusting the afterburning rate of the anode tail gas and the alternative fuel, and the problem that the thermoelectric output performance is reduced when the gas turbine operates under variable working conditions is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hybrid power generation technology, in particular to a combined cooling, heating and power system based on SOFC hybrid power. BACKGROUND

[0002] For mobile power scenarios such as ships, trains, and airplanes, or distributed energy system scenarios close to users, the cooling, heating and power load is complex and variable, and the power device often needs to operate efficiently under variable working conditions in the process of tracking the cooling, heating and power load. The hybrid power rated working condition efficiency of high-temperature solid oxide fuel cell-homogeneous compression internal combustion engine / high-temperature solid oxide fuel cell-gas turbine can reach 68%, and has the advantages of wide fuel applicability and high power generation efficiency.

[0003] Because the high-temperature solid oxide fuel cell works at about 800 DEG C, the thermal inertia is large, and the variable load response speed and adjustment capacity are weak, therefore, the homogeneous compression internal combustion engine and the gas turbine need to play the role of energy cascade utilization in the hybrid power combined cooling, heating and power system. However, in the process of variable load, both have their own limitations: the homogeneous compression internal combustion engine is difficult to control the combustion starting time because it is through compression of mixed gas to make it self-ignite, and the variable load operation domain is narrow, and if other alternative fuels are mixed to adjust the power output, the fuel is stratified in the cylinder and cannot be stably combusted. The gas turbine has high cost, and when operating under variable conditions, the thermal and power output performance is greatly reduced due to the change of gas flow and the limitation of impeller mechanical structure. SUMMARY

[0004] The purpose of the present application is to solve the above technical problems, and provide a combined cooling, heating and power system based on SOFC hybrid power, by adding a scroll internal combustion engine, the compression process of the scroll internal combustion engine is continuous, and the flow of intake air and exhaust gas can be accurately controlled, and the spark plug ignition can accurately control the combustion time, solving the problem that the combustion starting time of the homogeneous compression internal combustion engine is difficult to control; the second mixer adjusts the reburning rate of anode tail gas and alternative fuel to flexibly control the power of the internal combustion engine and the hot water output, solving the problem that the gas turbine has a large reduction in thermal and power output performance when operating under variable conditions.

[0005] In order to achieve the above object, the present application provides the following scheme: The present application discloses a combined heat and power system based on SOFC hybrid power, comprising a solid oxide fuel cell, a scroll internal combustion engine, a homogeneous compression ignition internal combustion engine, an absorption refrigerator, a heat exchange module, a first mixer, a second mixer and a third mixer; the scroll internal combustion engine and the homogeneous compression ignition internal combustion engine are both connected with a generator; the inlet end of the cathode of the solid oxide fuel cell is used for receiving air heated by the heat exchange module, and the outlet end of the cathode of the solid oxide fuel cell is used for discharging cathode tail gas, which is sent to the absorption refrigerator to obtain chilled water after being cooled by the heat exchange module; the inlet end of the anode of the solid oxide fuel cell is used for receiving fuel heated by the heat exchange module; the outlet end of the anode of the solid oxide fuel cell is used for discharging anode tail gas, which is sent to the first mixer and the second mixer respectively after being heated by the heat exchange module; the first mixer is used for mixing the anode tail gas and air and sending them into the homogeneous compression ignition internal combustion engine for combustion; the second mixer is used for mixing the anode tail gas, air and fuel and sending them into the scroll internal combustion engine for combustion; the scroll internal combustion engine and the homogeneous compression ignition internal combustion engine mix the flue gas after combustion by the third mixer, and obtain hot water by heat exchange with water in the hot water circulation pipeline via the heat exchange module.

[0006] Preferably, a compressor and a turbine connected with a generator are further included; the compressor is used for outputting compressed air, which is sent to the air inlet of the turbine after being heated by the heat exchange module; the air outlet of the turbine is used for discharging air after work, which is sent to the inlet end of the cathode of the solid oxide fuel cell after being heated by the heat exchange module.

[0007] Preferably, the anode tail gas discharged from the outlet end of the anode of the solid oxide fuel cell is divided into the first mixer and the second mixer by a flow divider.

[0008] Preferably, the heat exchange module comprises a first heat exchanger, a second heat exchanger, a third heat exchanger and a fourth heat exchanger; an inlet end of a first heat exchange channel of the first heat exchanger is connected to a fuel source, an outlet end of the first heat exchange channel of the first heat exchanger is connected to an inlet end of an anode of the solid oxide fuel cell, an inlet end of a second heat exchange channel of the first heat exchanger is connected to an outlet end of the anode of the solid oxide fuel cell, and an outlet end of the second heat exchange channel of the first heat exchanger is connected to an inlet end of a first heat exchange channel of the second heat exchanger; an outlet end of the first heat exchange channel of the second heat exchanger is connected to a confluence of the flow divider, a first flow distribution port of the flow divider is connected to the first mixer, and a second flow distribution port of the flow divider is connected to the second mixer; an inlet end of a second heat exchange channel of the second heat exchanger is connected to an air outlet of the turbine, and an outlet end of the second heat exchange channel of the second heat exchanger is connected to an inlet end of a cathode of the solid oxide fuel cell; an inlet end of a first heat exchange channel of the fourth heat exchanger is connected to the third mixer, and an outlet end of the first heat exchange channel of the fourth heat exchanger is connected to an inlet end of the absorption refrigerator; an inlet end of a second heat exchange channel of the fourth heat exchanger is connected to the compressor, and an outlet end of the second heat exchange channel of the fourth heat exchanger is connected to the turbine; an inlet end of a first heat exchange channel of the third heat exchanger is connected to an outlet end of the absorption refrigerator, and an outlet end of the first heat exchange channel of the third heat exchanger is connected to the outside; an inlet end of a second heat exchange channel of the third heat exchanger is connected to a return water side of a hot water circulation pipeline, and an outlet end of the second heat exchange channel of the third heat exchanger is connected to a water supply side of the hot water circulation pipeline.

[0009] Preferably, an outlet end of the first heat exchange channel of the third heat exchanger is connected to a gas-liquid separator, and a liquid outlet of the gas-liquid separator is connected to the hot water circulation pipeline.

[0010] Preferably, the heat exchange module further comprises a fifth heat exchanger, an inlet end of a first heat exchange channel of the fifth heat exchanger is connected to an outlet end of the second channel of the second heat exchanger, an outlet end of the first heat exchange channel of the fifth heat exchanger is connected to an inlet end of the cathode of the solid oxide fuel cell, an inlet end of a second heat exchange channel of the fifth heat exchanger is connected to an outlet end of the cathode of the solid oxide fuel cell, and an outlet end of the second heat exchange channel of the fifth heat exchanger is connected to the third mixer.

[0011] Preferably, the heat exchange module further comprises a sixth heat exchanger, an inlet end of a first heat exchange channel of the sixth heat exchanger is connected to a fuel source, an outlet end of the first heat exchange channel of the sixth heat exchanger is connected to an inlet end of the first heat exchange channel of the first heat exchanger, an inlet end of a second heat exchange channel of the sixth heat exchanger is connected to the second flow distribution port of the flow divider, and an outlet end of the second heat exchange channel of the sixth heat exchanger is connected to the second mixer.

[0012] Preferably, the absorption chiller obtains chilled water by exchanging heat with a cold water circulation pipeline.

[0013] Preferably, the system further includes an electric motor and a power converter. The solid oxide fuel cell is connected to the input terminal of the power converter, and the output terminal of the power converter, the generator of the scroll internal combustion engine, the generator of the homogeneous charge compression ignition internal combustion engine, and the generator of the turbine are all connected to the electric motor.

[0014] Preferably, the fuel is an alternative fuel.

[0015] The present invention achieves the following technical effects compared to the prior art: 1. In this SOFC hybrid cogeneration system: by adding a scroll internal combustion engine, the compression process of which is continuous, unlike the intermittent compression of traditional internal combustion engines, the intake and exhaust flow rates can be precisely controlled. Its spark plug ignition allows for precise control of the combustion timing, solving the problem of difficulty in controlling the combustion initiation time of homogeneous charge compression ignition (HCCI) internal combustion engines. A third mixer can recover waste heat from the flue gas of the two internal combustion engines to produce hot water. Adjusting the first mixer allows for regulation of the inlet temperature and load rate of the HCCI internal combustion engine. A second mixer adjusts the afterburning rate of the anode exhaust gas and alternative fuel to flexibly control the power of the internal combustion engine and the hot water output, solving the problem of a significant decrease in thermoelectric output performance of gas turbines under varying operating conditions. An absorption chiller can recover cold energy from the cathode exhaust gas.

[0016] Other technical solutions of the present invention have achieved the following technical effects compared with the prior art: 1. In this SOFC-based hybrid power combined cooling, heating and power system: a turbine is added, and the energy is deeply utilized in a cascade manner through the homogeneous charge compression ignition internal combustion engine, the scroll internal combustion engine and the turbine. In conjunction with each heat exchanger, it can recover sensible heat, latent heat and a large amount of water vapor from the anode exhaust gas to produce hot water, and recover waste heat from the cathode exhaust gas to produce cold energy. Under the premise of self-sufficiency of waste heat, the hybrid power system has a power generation efficiency of 68% and a combined cooling, heating and power efficiency of 92%, which is higher than that of a single SOFC power generation system.

[0017] 2. The power supply consists of four parts: solid oxide fuel cell, scroll internal combustion engine, homogeneous charge compression ignition internal combustion engine, and turbine. Therefore, if one of the power supply systems fails during operation, the other power generation devices can still operate normally, ensuring the stable operation of the entire system and greatly improving the overall stability and reliability of the system.

[0018] 3. The fuel is a mixed alternative fuel, which on the one hand realizes the deep utilization of lean anode tail gas and the stable combustion of alternative fuel, and on the other hand allows for a wide range of adjustment of power output and response speed. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained by analyzing these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram illustrating the structure and principle of a combined cooling, heating and power system based on SOFC hybrid power in an embodiment of the present invention; Figure 2 These are the operating parameters of each device in the SOFC-based combined cooling, heating and power system in this embodiment of the invention.

[0021] Explanation of reference numerals in the attached drawings: 1. Solid oxide fuel cell; 2. Scroll internal combustion engine; 3. Homogeneous charge compression ignition internal combustion engine; 4. Hot water circulation pipeline; 5. Absorption chiller; 6. First mixer; 7. Second mixer; 8. Third mixer; 9. Compressor; 10. Turbine; 11. Diverter; 12. First heat exchanger; 13. Second heat exchanger; 14. Third heat exchanger; 15. Fourth heat exchanger; 16. Fifth heat exchanger; 17. Sixth heat exchanger; 18. Power converter; 19. Electric motor; 20. First generator; 21. Second generator; 22. Third generator; 23. Cold water circulation pipeline. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments analyzed and obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The purpose of this invention is to provide a combined cooling, heating, and power (CCHP) system based on SOFC hybrid power to solve the problems existing in the prior art. By adding a scroll internal combustion engine, the compression process of which is continuous, the intake and exhaust flow can be precisely controlled. Its spark plug ignition can precisely control the combustion timing, solving the problem of difficulty in controlling the combustion initiation timing of homogeneous charge compression ignition (HCCI) internal combustion engines. By adjusting the afterburning rate of anode exhaust gas and alternative fuel through a second mixer, the power of the internal combustion engine and hot water output can be flexibly controlled, solving the problem of significant decrease in thermoelectric output performance of gas turbines under varying operating conditions.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Note: SOFC stands for Solid Oxide Fuel Cell.

[0026] like Figure 1 and Figure 2 As shown, this embodiment provides a combined cooling, heating, and power (CCHP) system based on SOFC hybrid power, including a solid oxide fuel cell 1, a scroll internal combustion engine 2, a homogeneous charge compression ignition (HCCI) internal combustion engine 3, an absorption chiller 5, a heat exchange module, a first mixer 6, a second mixer 7, a third mixer 8, a first generator 20, and a second generator 21. Specifically: the inlet end of the cathode of the solid oxide fuel cell 1 receives air heated by the heat exchange module. The outlet end of the cathode of the solid oxide fuel cell 1 discharges cathode exhaust gas, which is cooled by the heat exchange module and then sent to the absorption chiller 5. The absorption chiller 5 obtains chilled water through heat exchange with a cold water circulation pipe 23 (transferring cold energy to the cold water circulation pipe 23). The inlet end of the anode of the solid oxide fuel cell 1 receives fuel heated by the heat exchange module. The outlet end of the anode of the solid oxide fuel cell 1 discharges anode exhaust gas, which is heated by the heat exchange module and then sent to the first mixer 6 and the second mixer 7. The first mixer 6 mixes the anode exhaust gas and air and feeds them into the homogeneous charge compression ignition (HCCI) internal combustion engine 3 for combustion, generating power to drive the output shaft of the HCCI engine 3. The output shaft of the HCCI engine 3 is coaxially and fixedly connected to the input shaft of the first generator 20 to drive the first generator 20 to generate electricity. The second mixer 7 mixes the anode exhaust gas, air, and fuel and feeds them into the scroll internal combustion engine 2 for combustion, generating power to drive the output shaft of the scroll internal combustion engine 2. The output shaft of the scroll internal combustion engine 2 is coaxially and fixedly connected to the input shaft of the second generator 21 to drive the second generator 21 to generate electricity. The scroll internal combustion engine 2 and the HCCI engine 3 mix the combusted flue gas through the third mixer 8. The mixed flue gas then exchanges heat with water in the external hot water circulation pipe 4 through a heat exchange module to obtain hot water. The homogeneous charge compression ignition internal combustion engine utilizes thermal and chemical energy in the temperature range of 300℃ to 800℃; the scroll internal combustion engine utilizes the residual chemical energy in the anode exhaust gas at room temperature.

[0027] Working principle: ① In this SOFC hybrid power cogeneration system, when the operating strategy of determining heat based on electricity is adopted, the power output of solid oxide fuel cell 1 and the flow rate of anode exhaust gas are controlled by adjusting the current density.

[0028] ② After being heated by the heat exchange module, the fuel enters the anode of the solid oxide fuel cell 1 to participate in the electrochemical reaction. The resulting anode exhaust gas is discharged from the solid oxide fuel cell 1, and after being heated by the heat exchange module, it is split to the first mixer 6 and the second mixer 7. Air is added through the first mixer 6, and the ratio of air to anode exhaust gas is adjusted to regulate the inlet mixture temperature and load rate of the homogeneous charge compression ignition (HCCI) internal combustion engine 3, ensuring that the inlet mixture temperature of the HCCI internal combustion engine 3 is within the safe operating boundary. Air and fuel are added through the second mixer 7, and the ratio of air, fuel, and anode exhaust gas is adjusted to regulate the inlet gas temperature, alternative fuel quantity, power output, and flue gas heat capacity of the scroll internal combustion engine 2, achieving stable fuel combustion in the scroll internal combustion engine 2 and keeping it away from the detonation boundary. The flue gas from the scroll internal combustion engine 2 and the homogeneous charge compression ignition (HCCI) internal combustion engine 3 is collected and mixed through the third mixer 8, and then the mixed flue gas is heat-exchanged with the hot water circulation pipeline 4 using the heat exchange module to recover sensible and latent heat, achieving hot water supply and demand matching.

[0029] ③ After being heated by the air heat exchange module, the air enters the cathode of the solid oxide fuel cell 1 to participate in the electrochemical reaction. The generated cathode exhaust gas is cooled by the heat exchange module and then sent to the absorption chiller 5 to obtain chilled water. By controlling the air flow at the cathode inlet of the solid oxide fuel cell 1, the air supply and the supply and demand of cold energy are matched.

[0030] By combining the joint regulation of steps ① to ③, the supply and demand of electricity can be matched.

[0031] In one embodiment, the system further includes a compressor 9, a turbine 10, and a third generator 22. The output shaft of the turbine 10 is coaxially and fixedly connected to the input shaft of the third generator 22. The compressor 9 outputs compressed air, which is heated by a heat exchange module and then sent to the inlet of the turbine 10 to perform work within the turbine 10. This work drives the output shaft of the turbine 10 to rotate, which in turn drives the input shaft of the third generator 22 to rotate, thereby generating electricity. The outlet of the turbine 10 discharges the air after work has been performed. This air is heated by the heat exchange module and then sent to the inlet of the cathode of the solid oxide fuel cell 1. By controlling the airflow at the cathode inlet of the solid oxide fuel cell 1, the power output of the compressor 9 and the turbine 10, as well as the supply and demand of cooling energy, are adjusted.

[0032] In one embodiment, the anode exhaust gas discharged from the outlet of the solid oxide fuel cell 1 is split by a splitter 11 to a first mixer 6 and a second mixer 7.

[0033] In one embodiment, the heat exchange module includes a first heat exchanger 12, a second heat exchanger 13, a third heat exchanger 14, and a fourth heat exchanger 15. Wherein: The inlet end of the first heat exchange channel of the first heat exchanger 12 is connected to the fuel source, and the outlet end of the first heat exchange channel of the first heat exchanger 12 is connected to the inlet end of the anode of the solid oxide fuel cell 1. The inlet end of the second heat exchange channel of the first heat exchanger 12 is connected to the outlet end of the anode of the solid oxide fuel cell 1, and the outlet end of the second heat exchange channel of the first heat exchanger 12 is connected to the inlet end of the first heat exchange channel of the second heat exchanger 13.

[0034] The outlet end of the first heat exchange channel of the second heat exchanger 13 is connected to the manifold of the distributor 11. The first branch port of the distributor 11 is connected to the first mixer 6, and the second branch port of the distributor 11 is connected to the second mixer 7. The inlet end of the second heat exchange channel of the second heat exchanger 13 is connected to the outlet of the turbine 10, and the outlet end of the second heat exchange channel of the second heat exchanger 13 is connected to the inlet end of the cathode of the solid oxide fuel cell 1.

[0035] The inlet end of the first heat exchange channel of the fourth heat exchanger 15 is connected to the third mixer 8, and the outlet end of the first heat exchange channel of the fourth heat exchanger 15 is connected to the inlet end of the absorption chiller 5; the inlet end of the second heat exchange channel of the fourth heat exchanger 15 is connected to the compressor 9, and the outlet end of the second heat exchange pipe of the fourth heat exchanger 15 is connected to the turbine 10; the absorption chiller 5 exchanges cold energy with the chilled water circulation pipe 23.

[0036] The inlet end of the first heat exchange channel of the third heat exchanger 14 is connected to the outlet end of the absorption chiller 5, and the outlet end of the first heat exchange channel of the third heat exchanger 14 is connected to the outside. The inlet end of the second heat exchange channel of the third heat exchanger 14 is connected to the return water side of the hot water circulation pipe 4, and the outlet end of the second heat exchange channel of the third heat exchanger 14 is connected to the supply water side of the hot water circulation pipe 4.

[0037] Working principle: After passing through the first heat exchange channel of the first heat exchanger 12, the anode exhaust gas exchanges heat with the fuel in the second heat exchange channel, raising the fuel temperature to approximately 600°C and increasing the temperature at which the fuel enters the anode of the solid oxide fuel cell 1. Subsequently, the anode exhaust gas enters the first heat exchange channel of the second heat exchanger 13, exchanging heat with the air in the second heat exchange channel, thus heating the air and increasing the temperature at which it enters the cathode of the solid oxide fuel cell 1. The flue gas from the scroll internal combustion engine 2 and the homogeneous charge compression ignition internal combustion engine 3 passes through the third mixer 8 and enters the first heat exchange channel of the fourth heat exchanger 15. It then enters the absorption chiller 5, where it exchanges cooling energy with the chilled water circulation pipe 23, cooling the water in the chilled water circulation pipe 23 to obtain chilled water. The flue gas then passes through the absorption chiller 5 and enters the first heat exchange channel of the third heat exchanger 14, where it exchanges heat with the water in the hot water circulation pipe 4, heating the water in the hot water circulation pipe 4 to obtain hot water. The air compressed by compressor 9 will enter the second heat exchange channel of the fourth heat exchanger 15, and then exchange heat with the flue gas in the first heat exchange channel of the fourth heat exchanger 15, causing the air temperature to rise. The air with the increased temperature will enter the turbine 10, and then enter the second heat exchange channel of the second heat exchanger 13.

[0038] In one embodiment, the outlet end of the first heat exchange channel of the third heat exchanger 14 is connected to a gas-liquid separator (not shown), and the drain port of the gas-liquid separator is connected to the hot water circulation pipe 4. The gas-liquid separator can separate flue gas and condensate, and then the condensate is fed into the hot water circulation pipe 4 to increase the hot water flow and achieve hot water supply and demand matching.

[0039] In one embodiment, the heat exchange module further includes a fifth heat exchanger 16. The inlet end of the first heat exchange channel of the fifth heat exchanger 16 is connected to the outlet end of the second channel of the second heat exchanger 13, and the outlet end of the first heat exchange channel of the fifth heat exchanger 16 is connected to the inlet end of the cathode of the solid oxide fuel cell 1. The inlet end of the second heat exchange channel of the fifth heat exchanger 16 is connected to the outlet end of the cathode of the solid oxide fuel cell 1. The outlet end of the second heat exchange channel of the fifth heat exchanger 16 is connected to a third mixer 8.

[0040] Working principle: After being heated by the second heat exchanger 13, the air enters the first heat exchange channel of the fifth heat exchanger 16. At the same time, the cathode exhaust gas of the solid oxide fuel cell 1 enters the second heat exchange channel of the fifth heat exchanger 16. After the air exchanges heat with the cathode exhaust gas, the air temperature rises further and the cathode exhaust gas temperature decreases initially. It enters the cathode of the solid oxide fuel cell 1 to participate in the electrochemical reaction. The cathode exhaust gas in the second heat exchange channel of the fifth heat exchanger 16 is then introduced into the third mixer 8 to mix with the flue gas. The mixture of flue gas and cathode exhaust gas enters the first heat exchange channel of the fourth heat exchanger 15 to exchange heat with the air in the second heat exchange channel of the fourth heat exchanger 15. After the mixture is further cooled, it is introduced into the absorption chiller 5.

[0041] In one embodiment, the heat exchange module further includes a sixth heat exchanger 17. The inlet end of the first heat exchange channel of the sixth heat exchanger 17 is connected to a fuel source, and the outlet end of the first heat exchange channel of the sixth heat exchanger 17 is connected to the inlet end of the first heat exchange channel of the first heat exchanger 12. The inlet end of the second heat exchange channel of the sixth heat exchanger 17 is connected to the second branch port of the distributor 11. The outlet end of the second heat exchange channel of the sixth heat exchanger 17 is connected to the second mixer 7.

[0042] Working principle: Fuel first enters the first heat exchange channel of the sixth heat exchanger 17, where it undergoes a first heat exchange with the anode exhaust gas in the second heat exchange channel of the sixth heat exchanger 17. This results in a rise in fuel temperature and a decrease in anode exhaust gas temperature. Then, the fuel enters the second heat exchange channel of the first heat exchanger 12, where it undergoes a second heat exchange with the anode exhaust gas in the first heat exchange channel of the first heat exchanger 12 (this is the first heat exchange with the anode exhaust gas), further increasing the fuel temperature. In total, the fuel and anode exhaust gas undergo two heat exchanges, ensuring that the fuel effectively reaches the preset temperature and that the anode exhaust gas temperature is effectively reduced.

[0043] In one embodiment, the absorption chiller 5 obtains chilled water by exchanging heat with the cold water circulation pipe 23.

[0044] In one embodiment, a power converter 18 and an electric motor 19 are also included. The solid oxide fuel cell 1 is connected to the input terminal of the power converter 18, and the output terminal of the power converter 18 is connected to the electric motor 19. The generator (second generator 21) of the scroll internal combustion engine 2, the generator (first generator 20) of the homogeneous charge compression ignition internal combustion engine 3, and the generator (third generator 22) of the turbine 10 are all connected to the electric motor 19. The electricity generated by the solid oxide fuel cell 1, the scroll internal combustion engine 2, the homogeneous charge compression ignition internal combustion engine 3, and the turbine 10 is used to drive the output shaft of the electric motor 19 to rotate, thereby providing power for ships, trains, airplanes, etc.

[0045] In one embodiment, the fuel is an alternative fuel. The alternative fuel is preferably a low-carbon fuel.

[0046] This SOFC-based combined cooling, heating and power system has the following advantages: 1. High-efficiency fuel conversion and cascade utilization: The system achieves deep cascade utilization of energy through the homogeneous charge compression ignition internal combustion engine 3, the scroll internal combustion engine 2, and the turbine 10. In conjunction with the heat exchangers, it can recover sensible heat, latent heat, and a large amount of water vapor from the anode exhaust gas to produce hot water, and recover waste heat from the cathode exhaust gas to produce cold energy. Under the premise of self-sufficiency of waste heat, the hybrid power system has a power generation efficiency of 68% and a cooling, heating, and power efficiency of 92%, which is higher than that of a single SOFC power generation system.

[0047] 2. Safe and flexible control of heating, cooling, and electrical output; By adjusting the flow ratio of the anode exhaust gas of the solid oxide fuel cell 1 to the scroll internal combustion engine 2 and the homogeneous charge compression ignition (HCCI) internal combustion engine 3, the system operates within a safe operating range, avoiding combustion stratification in the HCCI engine 3 and knocking in the scroll internal combustion engine 2 when using alternative fuels. Flexible control of cold energy is achieved by adjusting the cathode inlet air flow. Flexible control and rapid response of electrical energy are achieved by adjusting the inlet fuel quantity of the solid oxide fuel cell 1 and the inlet fuel quantity of the scroll internal combustion engine 2 through the splitter 11, the first mixer 6, and the second mixer 7. Flexible control of thermal energy is achieved by adjusting the inlet fuel quantity of the scroll internal combustion engine 2 and the equivalence ratio of the internal combustion engine.

[0048] 3. Stability and reliability of the power system: The power supply consists of four parts: solid oxide fuel cell 1, scroll internal combustion engine 2, homogeneous charge compression ignition internal combustion engine 3, and turbine 10. Therefore, if one of the power supply systems fails during operation, the other power generation devices can still work normally, ensuring the stable operation of the entire system and greatly improving the overall stability and reliability of the system.

[0049] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A SOFC hybrid based combined cooling and power system, characterized by, The system comprises a solid oxide fuel cell, a scroll internal combustion engine, a homogeneous compression ignition internal combustion engine, an absorption refrigerator, a heat exchange module, a first mixer, a second mixer and a third mixer; the scroll internal combustion engine and the homogeneous compression ignition internal combustion engine are connected with a generator; an inlet end of a cathode of the solid oxide fuel cell is used to receive air heated by the heat exchange module, and an outlet end of the cathode is used to discharge cathode tail gas, which is cooled by the heat exchange module and then sent to the absorption refrigerator to obtain chilled water; an inlet end of an anode of the solid oxide fuel cell is used to receive fuel heated by the heat exchange module; an outlet end of the anode is used to discharge anode tail gas, which is heated by the heat exchange module and then sent to the first mixer and the second mixer respectively; the first mixer is used to mix the anode tail gas and air and send the mixture to the homogeneous compression ignition internal combustion engine for combustion; the second mixer is used to mix the anode tail gas, air and fuel and send the mixture to the scroll internal combustion engine for combustion; the scroll internal combustion engine and the homogeneous compression ignition internal combustion engine mix the flue gas of combustion by the third mixer, and obtain hot water by heat exchange with water in a hot water circulation pipeline via the heat exchange module.

2. The SOFC hybrid based combined cooling and power system according to claim 1, wherein, The system further comprises a compressor and a turbine connected with a generator; the compressor is used to output compressed air, which is heated by the heat exchange module and then sent to an air inlet of the turbine; an air outlet of the turbine is used to discharge worked air, which is heated by the heat exchange module and then sent to the inlet end of the cathode of the solid oxide fuel cell.

3. The SOFC hybrid based combined cooling and power system according to claim 2, wherein, The outlet end of the anode of the solid oxide fuel cell discharges anode tail gas, which is divided by a flow divider to the first mixer and the second mixer.

4. The SOFC hybrid based combined cooling and power system according to claim 3, wherein, The heat exchange module comprises a first heat exchanger, a second heat exchanger, a third heat exchanger and a fourth heat exchanger; the inlet end of the first heat exchange channel of the first heat exchanger is connected with a fuel source, the outlet end of the first heat exchange channel of the first heat exchanger is connected with the inlet end of the anode of the solid oxide fuel cell, the inlet end of the second heat exchange channel of the first heat exchanger is connected with the outlet end of the anode of the solid oxide fuel cell, and the outlet end of the second heat exchange channel of the first heat exchanger is connected with the inlet end of the first heat exchange channel of the second heat exchanger; the outlet end of the first heat exchange channel of the second heat exchanger is connected with the confluence port of the flow divider, the first flow distribution port of the flow divider is connected with the first mixer, and the second flow distribution port of the flow divider is connected with the second mixer; the inlet end of the second heat exchange channel of the second heat exchanger is connected with the gas outlet of the turbine, and the outlet end of the second heat exchange channel of the second heat exchanger is connected with the inlet end of the cathode of the solid oxide fuel cell; the inlet end of the first heat exchange channel of the fourth heat exchanger is connected with the third mixer, and the outlet end of the first heat exchange channel of the fourth heat exchanger is connected with the inlet end of the absorption refrigerator; the inlet end of the second heat exchange channel of the fourth heat exchanger is connected with the compressor, and the outlet end of the second heat exchange channel of the fourth heat exchanger is connected with the turbine; the inlet end of the first heat exchange channel of the third heat exchanger is connected with the outlet end of the absorption refrigerator, and the outlet end of the first heat exchange channel of the third heat exchanger is connected with the outside; the inlet end of the second heat exchange channel of the third heat exchanger is connected with the backwater side of the hot water circulation pipeline, and the outlet end of the second heat exchange channel of the third heat exchanger is connected with the water supply side of the hot water circulation pipeline.

5. The SOFC hybrid based combined cooling and power system according to claim 4, wherein, The outlet end of the first heat exchange channel of the third heat exchanger is connected with a gas-liquid separator, and the liquid outlet of the gas-liquid separator is connected with the hot water circulation pipeline.

6. The SOFC hybrid based combined cooling and power system of claim 4, wherein, The heat exchange module further comprises a fifth heat exchanger, the inlet end of the first heat exchange channel of the fifth heat exchanger is connected with the outlet end of the second channel of the second heat exchanger, the outlet end of the first heat exchange channel of the fifth heat exchanger is connected with the inlet end of the cathode of the solid oxide fuel cell, the inlet end of the second heat exchange channel of the fifth heat exchanger is connected with the outlet end of the cathode of the solid oxide fuel cell, and the outlet end of the second heat exchange channel of the fifth heat exchanger is connected with the third mixer.

7. The SOFC hybrid based combined cooling and power system of claim 4, wherein, The heat exchange module further comprises a sixth heat exchanger, the inlet end of the first heat exchange channel of the sixth heat exchanger is connected with a fuel source, the outlet end of the first heat exchange channel of the sixth heat exchanger is connected with the inlet end of the first heat exchange channel of the first heat exchanger, the inlet end of the second heat exchange channel of the sixth heat exchanger is connected with the second flow distribution port of the flow divider, and the outlet end of the second heat exchange channel of the sixth heat exchanger is connected with the second mixer.

8. The SOFC hybrid based combined cooling and power system of claim 1, wherein, The absorption refrigerator obtains chilled water by heat exchange with a cold water circulation pipeline.

9. The SOFC hybrid based combined cooling and power system of claim 2, wherein, Also included are an electric motor and a power converter, the solid oxide fuel cell being connected to an input of the power converter, an output of the power converter, an electric generator of the scroll internal combustion engine, an electric generator of the homogeneous compression ignition internal combustion engine, and an electric generator of the turbine being connected to the electric motor.

10. The SOFC hybrid based combined cooling and power system of claim 1, wherein, The fuel is an alternative fuel.

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