Combined cooling heating and power system based on integration of fuel cell and carnot cell

Abstract

The application belongs to the technical field of clean energy utilization, and discloses a cold-heat-power combined supply system based on fuel cell and Carnot cell integration, which comprises a fuel cell system, a Carnot cell system, a hot water storage tank and a water tank; the fuel cell system comprises a working medium passage, a preheating assembly, a cell stack and a combustor which are connected in sequence; the Carnot cell system comprises a heat exchanger, a water circulation passage, a heat storage unit, a Kalina power generation system and an ammonia refrigeration system; the heat storage unit, the water circulation passage and the heat exchanger are connected in sequence, the flue gas inlet of the heat exchanger is connected with high-temperature waste gas generated by the combustor, and the heat storage unit is connected with the Kalina power generation system and the ammonia refrigeration system; the hot water storage tank is connected with a hot water outlet generated by the ammonia refrigeration system; and the water tank is connected with a first water inlet of the heat storage unit. The application improves the energy conversion efficiency of the integrated system, greatly reduces the diversity of ship working medium, and facilitates the management of ship working medium.

Description

Technical Field

[0001] This invention belongs to the field of clean energy utilization technology, and in particular relates to a combined cooling, heating and power system based on the integration of fuel cells and Carnot batteries. Background Technology

[0002] The "dual carbon" target recommendation requires energy utilization to develop in a low-carbon / carbon-free direction. Solid oxide fuel cells (SOCs) are energy conversion devices with promising prospects in fields including ocean-going vessels due to their high efficiency, cleanliness, and low noise. SOCs can simultaneously meet the heating and cooling needs of ships operating at high temperatures. However, due to the drawbacks of SOCs, such as relatively soft output characteristics, slow start-up response, and poor transient response, they are often equipped with energy storage devices to improve system flexibility.

[0003] Currently, the most widely used configuration for ships is still the main diesel engine + diesel generator set, which often causes some pollution. The ship's heat demand is usually provided by the waste heat energy of the main engine, while the cooling demand is usually provided by the generator set driving the electric chiller, which undoubtedly reduces the ship's energy conversion efficiency. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a combined cooling, heating, and power system based on the integration of a fuel cell and a Carnot battery, aiming to solve or improve at least one of the aforementioned technical problems.

[0005] To achieve the above objectives, the present invention provides a combined cooling, heating, and power (CCHP) system based on the integration of a fuel cell and a Carnot battery, comprising:

[0006] A fuel cell system includes a working fluid passage, a preheating component, a fuel cell stack, and a burner connected in sequence. The high-temperature exhaust gas generated by the burner preheats the fuel working fluid in the working fluid passage through the preheating component.

[0007] The Carnot battery system includes a heat exchanger, a water circulation path, a thermal storage unit, a Carina power generation system, and an ammonia refrigeration system. The thermal storage unit, the water circulation path, and the heat exchanger are connected in sequence. The flue gas inlet of the heat exchanger is connected to the high-temperature exhaust gas generated by the burner. The high-temperature exhaust gas, after passing through the preheating component, enters the heat exchanger and exchanges heat with the circulating water in the water circulation path to form hot water. The hot water exchanges heat with the thermal storage unit through the water circulation path. The thermal storage unit is connected to both the Carina power generation system and the ammonia refrigeration system, providing the thermal energy required by the Carina power generation system and the ammonia refrigeration system.

[0008] A hot water storage tank is connected to the hot water outlet generated by the ammonia refrigeration system;

[0009] The water tank is connected to the first water inlet of the thermal storage unit.

[0010] Optionally, the water circulation path includes a water pump and a first expansion valve. The water pump is electrically connected to the battery stack and is connected to the first water outlet of the heat exchanger and the second water inlet of the heat storage unit. The first expansion valve is connected to the water inlet of the heat exchanger and the water outlet of the heat storage unit.

[0011] Optionally, the Karina power generation system includes a separator connected to the first heat outlet of the thermal storage unit. The ammonia-rich outlet of the separator is connected to an expander, and the expander is also connected to the ammonia-rich inlet of a mixer. The ammonia-lean inlet of the mixer is connected to a first regenerator via a second expansion valve. The first regenerator is connected to the ammonia-lean outlet of the separator, and the ammonia-lean outlet of the mixer is connected to the first regenerator via a condenser and a first working fluid pump in sequence.

[0012] Optionally, the ammonia refrigeration system includes a stripping tower connected to the second heat outlet of the heat storage unit. The hot water outlet of the stripping tower is connected to the hot water storage tank. The rich ammonia outlet of the stripping tower is connected in sequence to a cooler, a third expansion valve, and the rich ammonia inlet of an evaporator. The rich ammonia outlet of the evaporator is connected to an absorption tower. The basic ammonia outlet of the absorption tower is connected in sequence to the basic ammonia inlet of the stripping tower via a second working fluid pump and a second regenerator. The lean ammonia outlet of the stripping tower is connected in sequence to the lean ammonia inlet of the stripping tower via a second regenerator and a fourth expansion valve. The water outlet of the cooler is connected to the water inlet of the absorption tower via a condenser.

[0013] Optionally, the working fluid passage includes an air pump and a liquid ammonia tank connected to the battery stack.

[0014] Optionally, it also includes a water heater connected to the second water outlet of the heat exchanger, and the water heater is also connected to a liquid ammonia evaporator, which is connected to the liquid ammonia tank.

[0015] Optionally, the preheating assembly includes an ammonia preheater and an air preheater installed on the working fluid passage.

[0016] Optionally, the battery stack includes a first fuel cell and a second fuel cell arranged in parallel.

[0017] Optionally, the heat storage unit is a low-temperature heat storage tank, and the low-temperature heat storage tank is provided with a phase change heat storage material for heat exchange with the water circulation path.

[0018] Optionally, the thermal storage temperature of the low-temperature thermal storage tank is 200-250℃.

[0019] Compared with the prior art, the present invention has the following advantages and technical effects:

[0020] By employing heat exchangers, water circulation channels, and thermal storage units, the high-temperature exhaust gas generated by the burner is utilized to provide thermal power to the Karina power generation system and the ammonia refrigeration system, forming a coupling between fuel cells and Carnot batteries. Through thermal energy storage, the continuous supply of cooling, heating, and electricity to the ship is achieved, realizing the cascade utilization of thermal energy in the fuel cell system and realizing a combined cooling, heating, and power system. This improves the energy conversion efficiency of the integrated system, greatly reduces the diversity of working fluids on the ship, and facilitates the management of the ship's working fluids. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 This is a schematic diagram of the present invention.

[0023] In the diagram: 1. Liquid ammonia tank; 2. Air pump; 3. Liquid ammonia evaporator; 4. Ammonia preheater; 5. Air preheater; 6. First fuel cell; 7. Second fuel cell; 8. Burner; 9. Heat exchanger; 10. Water heater; 11. Water pump; 12. Low-temperature thermal storage tank; 13. First expansion valve; 14. Separator; 15. Expander; 16. Mixer; 17. Condenser; 18. First working fluid pump; 19. First regenerator; 20. Second expansion valve; 21. Desorption tower; 22. Cooler; 23. Third expansion valve; 24. Evaporator; 25. Condenser; 26. Absorption tower; 27. Second working fluid pump; 28. Second regenerator; 29. ​​Fourth expansion valve; 30. Water tank; 31. Hot water storage tank. Detailed Implementation

[0024] 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 obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] 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.

[0026] Reference Figure 1 As shown, this embodiment provides a combined cooling, heating, and power (CCHP) system based on a fuel cell and a Carnot battery integration, comprising:

[0027] The fuel cell system includes a working fluid passage, a preheating component, a fuel cell stack, and a burner 8 connected in sequence. The high-temperature exhaust gas generated by the burner 8 preheats the fuel working fluid in the working fluid passage through the preheating component.

[0028] The Carnot battery system includes a heat exchanger 9, a water circulation path, a thermal storage unit, a Carina power generation system, and an ammonia refrigeration system. The thermal storage unit, the water circulation path, and the heat exchanger 9 are connected in sequence, and the flue gas inlet of the heat exchanger 9 is connected to the high-temperature exhaust gas generated by the burner 8. The high-temperature exhaust gas after passing through the preheating component enters the heat exchanger 9 and exchanges heat with the circulating water in the water circulation path to form hot water. The hot water exchanges heat with the thermal storage unit through the water circulation path. The thermal storage unit is connected to the Carina power generation system and the ammonia refrigeration system respectively, providing the thermal energy required by the Carina power generation system and the ammonia refrigeration system.

[0029] Hot water storage tank 31 is connected to the hot water outlet generated by the ammonia refrigeration system;

[0030] Water tank 30 is connected to the first water inlet of the thermal storage unit.

[0031] By employing heat exchanger 9, water circulation path, and thermal storage unit, the high-temperature exhaust gas generated by burner 8 is utilized to provide thermal power to the Karina power generation system and ammonia refrigeration system, forming a coupling between fuel cell and Carnot battery. Through thermal energy storage, the continuous supply of cooling, heating, and electricity to the ship can be achieved, realizing the cascade utilization of thermal energy in the fuel cell system, realizing a combined cooling, heating, and power system, improving the energy conversion efficiency of the integrated system, greatly reducing the diversity of ship working fluids, and facilitating the management of ship working fluids.

[0032] Water from water tank 30 is heated (>200℃) after passing through the heat storage unit to form superheated steam. After passing through the desorption tower 21, it provides heat for the generation of ammonia-rich solution. The resulting hot water enters the hot water storage tank 31 for use by the crew. The temperature of the hot water used by the crew is higher than 60℃.

[0033] In a further optimized scheme, the water circulation path includes a water pump 11 and a first expansion valve 13. The water pump 11 is electrically connected to the battery stack, and the water pump 11 is connected to the first water outlet of the heat exchanger 9 and the second water inlet of the heat storage unit, respectively. The first expansion valve 13 is connected to the water inlet of the heat exchanger 9 and the water outlet of the heat storage unit, respectively.

[0034] The residual electrical energy generated by the battery stack drives the water pump 11, which, in conjunction with the first expansion valve 13, causes the room temperature water in the water tank 30 to circulate.

[0035] Further optimization of the scheme: the Karina power generation system includes a separator 14, which is connected to the first heat outlet of the thermal storage unit. The rich ammonia outlet of the separator 14 is connected to an expander 15, which is also connected to the rich ammonia inlet of a mixer 16. The lean ammonia inlet of the mixer 16 is connected to a first regenerator 19 through a second expansion valve 20. The first regenerator 19 is connected to the lean ammonia outlet of the separator 14, and the lean ammonia outlet of the mixer 16 is connected to the first regenerator 19 through a condenser 17 and a first working fluid pump 18 in sequence.

[0036] Thermal energy is supplied to separator 14 through the thermal storage unit. Separator 14 produces ammonia-rich solution and ammonia-lean solution. The ammonia-rich solution first flows into expander 15 to provide power for turbine, and then flows into mixer 16. At the same time, the ammonia-lean solution in separator 14 flows into mixer 16 through first regenerator 19 and second expansion valve 20 to merge with ammonia-rich solution to form base ammonia solution. The base ammonia solution enters first regenerator 19 through condenser 17 and first working fluid pump 18, absorbs the waste heat of the ammonia-lean solution, and then enters separator 14 to form a cycle.

[0037] Further optimization of the scheme: the ammonia refrigeration system includes a stripping tower 21, which is connected to the second heat outlet of the heat storage unit. The hot water outlet of the stripping tower 21 is connected to the hot water storage tank 31. The rich ammonia outlet of the stripping tower 21 is connected in sequence to the rich ammonia inlet of the evaporator 24 via the cooler 22, the third expansion valve 23, and the evaporator 24. The rich ammonia outlet of the evaporator 24 is connected to the absorption tower 26. The basic ammonia outlet of the absorption tower 26 is connected in sequence to the basic ammonia inlet of the stripping tower 21 via the second working fluid pump 27 and the second regenerator 28. The lean ammonia outlet of the stripping tower 21 is connected in sequence to the lean ammonia inlet of the stripping tower 21 via the second regenerator 28 and the fourth expansion valve 29. The water outlet of the cooler 22 is connected to the water inlet of the absorption tower 26 via the condenser 25.

[0038] Heat energy is supplied to the stripping tower 21 through the heat storage unit, so that the ammonia-rich solution formed in the stripping tower 21 enters the cooler 22, where the condensed water flows into the absorption tower 26 through the condenser 25. The cooled ammonia-rich solution is depressurized through the third expansion valve 23 to form liquid ammonia, which then enters the evaporator 24 to provide cooling energy for the ship. The ammonia-rich solution leaving the evaporator 24 and entering the absorption tower 26, together with the lean ammonia solution that has been depressurized through the second regenerator 28 and the fourth expansion valve 29 and enters the absorption tower 26, as well as the water that has entered the absorption tower 26 through the cooler 22 and the condenser 25, forms a basic ammonia solution. The basic ammonia solution is returned to the second regenerator 28 through the second working fluid pump 27. The basic ammonia solution leaving the absorption tower 26 is pressurized by the second working fluid pump 27 and enters the second regenerator 28, where it absorbs the residual heat of the lean ammonia solution and then enters the stripping tower 21 to form a cycle.

[0039] Further optimization of the scheme includes an air pump 2 and a liquid ammonia tank 1 connected to the battery stack.

[0040] Liquid ammonia tank 1 and air pump 2 provide the working fluid required for the battery stack.

[0041] Further optimization of the scheme also includes a water heater 10, which is connected to the second water outlet of the heat exchanger 9. The water heater 10 is also connected to the liquid ammonia evaporator 3, which is connected to the liquid ammonia tank 1.

[0042] The circulating water in heat exchanger 9 can also enter water heater 10 through the second water outlet to provide hot water for the ship, and then enter liquid ammonia evaporator 3 to realize the evaporation of liquid ammonia.

[0043] The scheme was further optimized, and the preheating components include an ammonia preheater 4 and an air preheater 5 installed on the working fluid passage.

[0044] The high-temperature exhaust gas generated by burner 8 first passes through ammonia preheater 4 and air preheater 5 to preheat the working fluid generated by air pump 2 and liquid ammonia tank 1, thereby improving the efficiency of the battery stack.

[0045] The scheme is further optimized so that the battery stack includes a first fuel cell 6 and a second fuel cell 7 arranged in parallel.

[0046] Achieving partial power decoupling in the battery stack improves its reliability.

[0047] The scheme was further optimized so that the heat storage unit is a low-temperature heat storage tank 12, and the low-temperature heat storage tank 12 is equipped with a phase change heat storage material for heat exchange with the water circulation channel.

[0048] The scheme was further optimized so that the heat storage temperature of the low-temperature thermal storage tank 12 is 200-250℃.

[0049] Operating conditions for this invention:

[0050] Operating Condition 1: During normal ship operation, part of the electrical energy of the battery stack and the waste heat energy of the exhaust gas of the burner 8 are transferred to the low-temperature thermal storage tank 12 through the heat exchanger 9 and the water circulation passage. A small portion of the thermal energy (80-90%) is stored through phase change thermal energy storage material, and the remaining thermal energy is output as cold, heat and electricity through the Karina power generation system and the ammonia refrigeration system.

[0051] Operating Condition 2: When the ship is docked and the fuel cell system is shut down, the water circulation path stops operating, and the remaining heat energy in the cryogenic heat storage tank 12 continues to be converted into heat and electricity output to meet the ship's heating and cooling needs as well as the needs of auxiliary machinery and electrical systems.

[0052] Operating Condition 3: When the ship's propulsion power load changes within a small range (the maximum range of load change is the output power of the Karina power generation system), rapid load switching can be achieved by changing the output power load of the Karina power generation system;

[0053] Operating Condition 4: When the ship's propulsion power load changes over a wide range, the net power output of the fuel cell system can be rapidly changed by altering the water circulation path and the load on heat exchanger 9.

[0054] This invention enables the system to achieve high flexibility by adjusting the energy storage and release ratio under different operating conditions.

[0055] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0056] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A combined cooling, heating, and power (CCHP) system based on fuel cell and Carnot battery integration, characterized in that, include: The fuel cell system includes a working fluid passage, a preheating component, a battery stack, and a burner (8) connected in sequence. The high-temperature exhaust gas generated by the burner (8) preheats the working fluid in the working fluid passage through the preheating component. The Carno battery system includes a heat exchanger (9), a water circulation path, a thermal storage unit, a Carina power generation system, and an ammonia refrigeration system. The thermal storage unit, the water circulation path, and the heat exchanger (9) are connected in sequence. The flue gas inlet of the heat exchanger (9) is connected to the high-temperature exhaust gas generated by the burner (8). The high-temperature exhaust gas after passing through the preheating component enters the heat exchanger (9) and exchanges heat with the circulating water in the water circulation path to form hot water. The hot water exchanges heat with the thermal storage unit through the water circulation path. The thermal storage unit is connected to the Carina power generation system and the ammonia refrigeration system respectively, providing the thermal power required by the Carina power generation system and the ammonia refrigeration system. A hot water storage tank (31) is connected to the hot water outlet generated by the ammonia refrigeration system; The water tank (30) is connected to the first water inlet of the thermal storage unit; The heat storage unit is a low-temperature heat storage tank (12), and the low-temperature heat storage tank (12) is provided with a phase change heat storage material for heat exchange with the water circulation channel; the heat storage temperature of the low-temperature heat storage tank (12) is 200-250℃.

2. The combined cooling, heating, and power system based on fuel cell and Carnot battery integration according to claim 1, characterized in that: The water circulation path includes a water pump (11) and a first expansion valve (13). The water pump (11) is electrically connected to the battery stack, and the water pump (11) is connected to the first water outlet of the heat exchanger (9) and the second water inlet of the heat storage unit, respectively. The first expansion valve (13) is connected to the water inlet of the heat exchanger (9) and the water outlet of the heat storage unit, respectively.

3. The combined cooling, heating, and power system based on fuel cell and Carnot battery integration according to claim 1, characterized in that: The Karina power generation system includes a separator (14) connected to the first heat outlet of the thermal storage unit. The rich ammonia outlet of the separator (14) is connected to an expander (15). The expander (15) is also connected to the rich ammonia inlet of a mixer (16). The lean ammonia inlet of the mixer (16) is connected to a first regenerator (19) via a second expansion valve (20). The first regenerator (19) is connected to the lean ammonia outlet of the separator (14). The lean ammonia outlet of the mixer (16) is connected to the first regenerator (19) via a condenser (17) and a first working fluid pump (18) in sequence.

4. The combined cooling, heating, and power system based on fuel cell and Carnot battery integration according to claim 1, characterized in that: The ammonia refrigeration system includes a desorption tower (21), which is connected to the second heat outlet of the heat storage unit. The hot water outlet of the desorption tower (21) is connected to the hot water storage tank (31). The rich ammonia outlet of the desorption tower (21) is connected in sequence to the rich ammonia inlet of the cooler (22), the third expansion valve (23), and the evaporator (24). The rich ammonia outlet of the evaporator (24) is connected to an absorption tower (26). The basic ammonia outlet of the absorption tower (26) is connected in sequence to the basic ammonia inlet of the desorption tower (21) through the second working fluid pump (27) and the second regenerator (28). The lean ammonia outlet of the desorption tower (21) is connected in sequence to the lean ammonia inlet of the absorption tower (26) through the second regenerator (28) and the fourth expansion valve (29). The water outlet of the cooler (22) is connected to the water inlet of the absorption tower (26) through the condenser (25).

5. The combined cooling, heating, and power system based on fuel cell and Carnot battery integration according to claim 1, characterized in that: The working fluid passage includes an air pump (2) and a liquid ammonia tank (1) connected to the battery stack.

6. The combined cooling, heating, and power system based on fuel cell and Carnot battery integration according to claim 5, characterized in that: It also includes a water heater (10), which is connected to the second water outlet of the heat exchanger (9), and the water heater (10) is also connected to a liquid ammonia evaporator (3), which is connected to the liquid ammonia tank (1).

7. The combined cooling, heating, and power system based on fuel cell and Carnot battery integration according to claim 1, characterized in that: The preheating components include an ammonia preheater (4) and an air preheater (5) installed on the working fluid passage.

8. The combined cooling, heating, and power system based on fuel cell and Carnot battery integration according to claim 1, characterized in that: The battery stack includes a first fuel cell (6) and a second fuel cell (7) connected in parallel.

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