Combustion gas turbine and CO2 Rankine cycle combined system and method for recycling ammonia gas cold energy

Abstract

The invention provides a gas turbine and CO2 Rankine cycle combined system and method for recycling ammonia cold energy. The system comprises an ammonia gas turbine module and a transcritical CO2 Rankine cycle module. The ammonia gas turbine module is provided with a first cooler, an ammonia gas preheater and an air preheater, ammonia gas and air are mixed and combusted in a combustion chamber to generate smoke and release heat, and the smoke exchanges heat in a heat collector and a smoke low-temperature heat regenerator after entering an ammonia gas turbine to do work. In the transcritical CO2 Rankine cycle module, a CO2 low-temperature heat regenerator and a smoke low-temperature heat regenerator are connected in parallel and then are sequentially connected with a high-temperature heat regenerator and a heat collector, first-stage waste heat of smoke in the heat collector is used for carrying out first-stage preheating on CO2, preheated CO2 gas enters a CO2 turbine to do work, released high-temperature CO2 gas flows back into the high-temperature heat regenerator and the CO2 low-temperature heat regenerator to carry out heat exchange, and the CO2 low-temperature heat regenerator and the high-temperature heat regenerator are communicated with the heat collector. And the low-temperature CO2 gas is cooled to the temperature below the critical point by utilizing the cold energy of liquid ammonia recovered by the first cooler and is circulated in the transcritical CO2 Rankine cycle module.

Description

Technical Field

[0001] The present invention belongs to the field of comprehensive energy utilization, and in particular relates to a combined system and method for recovering ammonia cooling energy from a gas turbine and a CO2 Rankine cycle. Background Art

[0002] As a refrigerant, ammonia has good thermodynamic and physical properties and is friendly to the atmospheric environment. It is a good carbon-free fuel and can be used as a power system for large ships sailing far away. It is also an important technical direction for carbon emission reduction in thermal power transformation. However, due to its relatively high ignition point, it needs to be fully preheated before entering the combustion chamber. In addition, ammonia combustion mainly produces water and nitrogen, and the latent heat of water vapor in the flue gas is difficult to utilize. Therefore, the thermal efficiency of the ammonia gas turbine cycle is only 36%. Therefore, the recovery of cold energy during the transportation of liquid ammonia and the comprehensive utilization of flue gas energy of gas turbines are a major focus of improving the utilization efficiency of ammonia.

[0003] CO2 has strong chemical stability, thermodynamic properties and low critical temperature (30.8℃), and can be used as a Rankine cycle working fluid. Its cycle structure is simple and its cycle thermal efficiency is high. It is often used for low-temperature heat source recovery or participating in the bottom cycle of a combined cycle. However, since the critical temperature of CO2 is not much different from room temperature, conventional direct heat exchange cooling methods cannot stably cool it to below 30℃, so additional refrigeration equipment or other cooling methods are required. In addition, the density of CO2 changes with temperature near the critical point, and the density and specific heat change dramatically. There is a phenomenon of transformation from liquid to supercritical gas and liquid coexistence, which easily causes a pinch point in the regenerator and affects the heat exchange efficiency. At present, the split-flow recompression arrangement is generally used to solve the problem of the regenerator pinch point to improve the overall thermal efficiency of the cycle. However, the split-flow recompression arrangement adds a recompressor, and its recompression position is far away from the critical point of CO2, which increases the compression power consumption and increases the complexity of the system. Summary of the invention

[0004] In view of the above technical problems, the present invention provides a combined system and method for recovering ammonia cooling energy from a gas turbine and a cross-CO2 Rankine cycle, in order to at least partially solve the above technical problems. The specific technical solutions are as follows:

[0005] As a first aspect of the present invention, a combined system of ammonia cold energy recovery gas turbine and CO2 Rankine cycle is provided, comprising an ammonia gas turbine module and a transcritical CO2 Rankine cycle module;

[0006] The ammonia gas turbine module is provided with a first cooler for vaporizing liquid ammonia to release cold energy, an ammonia preheater and a combustion chamber for heating the vaporized ammonia to a combustible temperature of ammonia according to the flow direction of ammonia; an air preheater and a combustion chamber are provided according to the flow direction of air, and ammonia and air are mixed and burned in the combustion chamber to generate flue gas and release heat; an ammonia turbine, a heat extractor and a flue gas low-temperature heat regenerator are provided according to the flow direction of flue gas;

[0007] The transcritical CO2 Rankine cycle module is provided with a CO2 low-temperature regenerator, a high-temperature regenerator, a heat collector and a CO2 turbine, wherein the CO2 low-temperature regenerator and the flue gas low-temperature regenerator are connected in parallel, and the transcritical CO2 Rankine cycle module and the ammonia gas turbine module share a heat collector.

[0008] According to the flow direction of CO2 on the low-temperature side, CO2 is preheated through the CO2 low-temperature regenerator and the flue gas low-temperature regenerator respectively. The preheated CO2 gas is mixed and sequentially enters the high-temperature regenerator and the heat extractor for step-by-step temperature increase. The preheated CO2 gas enters the CO2 turbine to perform work and release high-temperature CO2 gas.

[0009] According to the flow direction of the CO2 gas on the high-temperature side, the hot side outlet of the CO2 turbine is connected in sequence with the hot side inlet of the high-temperature regenerator and the hot side inlet of the CO2 low-temperature regenerator, and the hot side outlet of the CO2 low-temperature regenerator is connected with the hot side inlet of the first cooler. The high-temperature side CO2 gas is cooled step by step through the high-temperature regenerator and the CO2 low-temperature regenerator to obtain low-temperature CO2 gas, and the low-temperature CO2 gas is cooled to a temperature below the critical point by using the cold energy released by liquid ammonia recovered by the first cooler. The obtained low-temperature liquid CO2 circulates in the transcritical CO2 Rankine cycle module.

[0010] As a second aspect of the present invention, a method for combining a gas turbine for recovering ammonia cooling energy and a CO2 Rankine cycle is provided, using the above-mentioned combined system of a gas turbine for recovering ammonia cooling energy and a CO2 Rankine cycle, wherein the method comprises:

[0011] After the liquid ammonia is vaporized into ammonia gas and the cold energy of the liquid ammonia is recovered, the preheated air and ammonia gas are introduced into the combustion chamber for combustion to generate flue gas and release heat. The flue gas flows into the ammonia turbine to perform work, output electrical energy and generate flue gas.

[0012] According to the flow direction of the flue gas, the primary waste heat of the flue gas is used to perform primary cooling in the heat extractor. After the primary cooling, the secondary waste heat of the flue gas is used to perform secondary cooling in the air preheater and the ammonia preheater respectively. After the secondary cooling, the tertiary waste heat of the flue gas is used to perform tertiary cooling in the flue gas low-temperature regenerator to obtain low-temperature flue gas.

[0013] According to the flow direction of CO2 on the low-temperature side, the low-temperature liquid CO2 flows into the flue gas low-temperature regenerator and the CO2 low-temperature regenerator for three-stage heating. The heated CO2 gas merges and flows into the high-temperature regenerator for two-stage heating, and enters the heat collector for one-stage heating. The CO2 gas heated step by step flows into the CO2 turbine to do work, output electrical energy and release high-temperature CO2 gas.

[0014] According to the flow direction of CO2 gas on the high-temperature side, the high-temperature CO2 gas flows back to the high-temperature regenerator for primary heat recovery of the CO2 gas, and the CO2 gas after the primary heat recovery flows back to the CO2 low-temperature regenerator for secondary heat recovery of the low-temperature liquid CO2, and the temperature of the CO2 gas on the high-temperature side is gradually reduced to obtain low-temperature CO2 gas. After the low-temperature CO2 gas is cooled to a temperature below the critical point by the cold energy recovered by the first cooler, the obtained low-temperature liquid CO2 circulates in the transcritical CO2 Rankine cycle module.

[0015] Based on the above technical solution, the present invention provides a combined system and method of a gas turbine for recovering ammonia cooling energy and a CO2 Rankine cycle, which includes at least one of the following beneficial effects:

[0016] (1) According to an embodiment of the present invention, by setting a first cooler in the flow direction of ammonia to recover the cold energy of ammonia, the low-temperature CO2 gas refluxed in the CO2 Rankine cycle can be cooled to a liquid state. The flue gas generated by the combustion of preheated ammonia and air in the combustion chamber enters the ammonia turbine to expand and do work, and outputs electrical energy and flue gas. The heat collector is used as a coupling point between the ammonia gas turbine module and the transcritical CO2 Rankine cycle module, and the flue gas and CO2 are exchanged for the two modules respectively. In the flow direction of the flue gas, the primary waste heat of the flue gas in the heat collector can be used to heat the low-temperature side CO2 gas in the CO2 Rankine cycle module, and the secondary waste heat of the residual flue gas can be used to preheat the air and ammonia respectively, thereby improving the combustion efficiency when the two are combined and reducing the generation of NOx during the combustion of ammonia; the tertiary waste heat of the residual flue gas flows into the flue gas low-temperature regenerator, and can release heat to the liquid CO2 entering the flue gas low-temperature regenerator, and gasify the liquid CO2 into CO2 gas. Therefore, after the gas turbine outputs electricity, the flue gas is subjected to three-stage heat exchange and releases heat step by step, which comprehensively utilizes the energy of each part of the ammonia gas turbine module. After three-stage heat exchange, the flue gas temperature is finally reduced to near the dew point, which efficiently converts the energy contained in the flue gas and improves the net efficiency of the cycle.

[0017] (2) According to an embodiment of the present invention, in the flow direction of CO2 on the low-temperature side, the flue gas low-temperature regenerator and the CO2 low-temperature regenerator are connected in parallel and then connected to the high-temperature regenerator and the heat collector in sequence to achieve step-by-step heating of CO2 on the low-temperature side. The primary waste heat of the flue gas in the heat collector is used to further heat the CO2 gas in the high-temperature regenerator (i.e., primary heating). The heated CO2 gas enters the CO2 turbine to expand and do work and release high-temperature CO2 gas. In the flow direction of the high-temperature CO2 gas, by connecting the CO2 turbine, the high-temperature regenerator and the CO2 low-temperature regenerator in sequence, the high-temperature CO2 gas is used to preheat the CO2 gas on the low-temperature side, and the high-temperature CO2 gas is cooled step by step to obtain the low-temperature CO2 gas. By using the tertiary waste heat after the flue gas is gradually cooled as the energy matching the gasification of liquid CO2 in the flue gas low-temperature regenerator, the liquid CO2 is heated, thus avoiding the power consumption generated by introducing the re-compressor. At the same time, the tertiary waste heat of the flue gas is introduced in the process of diverting the low-temperature liquid CO2, so that the temperature gradients on both sides near the low-temperature regenerator are matched, thus solving the problem of pinch points that are easily generated at both ends of the regenerator.

[0018] (3) According to an embodiment of the present invention, the obtained low-temperature CO2 gas is transported to a first cooler and cooled with liquid ammonia to obtain liquid CO2. The liquid CO2 can be recycled as a working fluid of a transcritical CO2 Rankine cycle module, thereby achieving zero carbon emissions and no pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the framework of a combined system of a gas turbine and CO2 Rankine cycle for recovering ammonia cooling energy according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the framework of a combined system of a gas turbine for recovering ammonia cold energy and a CO2 Rankine cycle in another embodiment of the present invention.

[0021] [Description of Reference Numerals]

[0022] 1-air compressor, 2-air preheater, 3-liquid ammonia pump, 4-first cooler, 5-ammonia preheater, 6-combustion chamber, 7-ammonia turbine, 8-heat extractor, 9-CO2 pump, 10-flue gas low-temperature regenerator, 11-CO2 low-temperature regenerator, 12-high-temperature regenerator, 13-CO2 turbine, 14-ammonia compressor, 15-condenser, 16-throttle valve, 17-second cooler, 18-heat exchanger. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0024] Ammonia has good thermodynamics, physical properties and environmental friendliness as a refrigerant. When used as a fuel gas, it has a high hydrogen content and can be liquefied at normal pressure of -33°C or 0.9MPa at room temperature. There is no carbon emission after combustion, and its energy density is equivalent to 3 times that of hydrogen, which is convenient for storage and transportation. It is a possible choice for clean power generation fuel after hydrogen fuel. In addition, ammonia has the characteristics of easy preparation, low cost, high purity, and ammonia does not corrode metal parts, making it a green energy source. However, ammonia has a relatively high ignition point (700-780°C) and is not easy to burn. It needs to be fully preheated before entering the combustion chamber, such as by catalytic cracking to promote stable combustion of ammonia. Therefore, how to comprehensively utilize the cold energy of ammonia and the energy required to heat ammonia to the combustion temperature is a major problem faced in improving the utilization efficiency of ammonia.

[0025] CO2 has strong chemical stability, a critical temperature of 30.8°C, and is easy to achieve production conditions. The organic Rankine cycle is a transcritical closed cycle with a simple cycle structure and high cycle thermal efficiency. It does not require a high heat extraction temperature, so it is often used for low-temperature heat source recovery or participating in the bottom cycle of a combined cycle. In the related art, CO2 is used as a working fluid and applied to the Rankine cycle. The pump compresses and pressurizes the CO2, extracts heat through the evaporator to the turbine to expand and do work, and then cools it to below the critical temperature of CO2 and returns it to the front of the CO2 pump to close the cycle. On the basis of this basic cycle, a regenerator is arranged between the CO2 pump and the turbine to improve the system efficiency, but refrigeration technology is still required before CO2 enters the CO2 pump to reduce the CO2 working fluid to below the critical temperature. In addition, since the critical temperature of CO2 is not much different from the room temperature, conventional direct heat exchange cooling methods are used, such as air cooling and water cooling. However, these methods cannot efficiently and stably cool the working fluid CO2 to below 30°C, and then additional refrigeration equipment or other cooling equipment still needs to be introduced.

[0026] In addition, when CO2 is near the critical point and its density changes from liquid to supercritical state with temperature, there is a phenomenon of gas-liquid coexistence, and the density and specific heat change dramatically. The current transcritical CO2 Rankine cycle and the simple reheat arrangement in the closed supercritical Brayton cycle have the same reheater pinch point problem, which in turn affects the heat exchange efficiency. In order to solve this problem, the closed supercritical Brayton cycle proposes a split recompression arrangement, which divides the reheater into a high-temperature reheater without generating a pinch point, and the other part is a low-temperature reheater. After part of the working fluid is diverted at the outlet of the low-temperature reheater to enter the recompressor, it merges between the high-temperature and low-temperature reheaters to improve the overall thermal efficiency of the cycle. However, the split recompression arrangement adds a recompressor, and the recompression position is far away from the critical point of CO2, which increases the compression power consumption and increases the system complexity.

[0027] In view of this, the present invention provides a combined system and method for recovering ammonia cooling energy of a gas turbine and CO2 Rankine cycle. Based on the idea of ​​comprehensive energy utilization and temperature gradient matching, the present invention proposes a method for combining the transcritical CO2 cooling part with the liquid ammonia cooling part, based on the comprehensive utilization of flue gas energy in the ammonia gas turbine unit, the effective utilization of liquid ammonia cooling energy, and the energy coupling utilization of the Rankine cycle with CO2 as the working fluid in the combined cycle. Matching, the three-stage cooling of the ammonia gas turbine flue gas is effectively utilized and the heat is recovered by means of split-flow heat recovery. Compared with the previous combined power generation technology of organic Rankine cycle and gas turbine cycle, the cycle of the present invention has the characteristics of high cycle efficiency, simple cycle structure, no carbon emissions, and ideally no environmental pollution emissions.

[0028] Specifically, the first aspect of the present invention provides a combined system of ammonia cold energy recovery gas turbine and CO2 Rankine cycle, including an ammonia gas turbine module and a transcritical CO2 Rankine cycle module. In the ammonia gas turbine module, a first cooler (cool1, C1), an ammonia preheater (ammonia preheater, PH-AM) and a combustion chamber (combustor, C) are arranged according to the flow direction of ammonia; an air preheater (air preheater, PH-A) and a combustion chamber are arranged according to the flow direction of air; an ammonia turbine (ammonia turbine, T-AM), a heat extractor (heater, H), ammonia preheater and air preheater in parallel, and a low temperature regenerator for flue gas (Low temperature regenerator for flue gas, LTR-F) are arranged according to the flow direction of flue gas. The transcritical CO2 Rankine cycle module is set up according to the flow direction of CO2 on the low temperature side. The flue gas low temperature regenerator and the CO2 low temperature regenerator (Low temperature regenerator for CO2, LTR-C) are connected in parallel and then connected to the high temperature regenerator and the heat collector in sequence; according to the flow direction of CO2 gas on the high temperature side, the heat collector, CO2 turbine (CO2 turbine, TC) are connected to the hot side inlet of the high temperature regenerator and the hot side inlet of the CO2 low temperature regenerator in sequence, and the hot side outlet of the CO2 low temperature regenerator is connected to the hot side inlet of the first cooler, and the obtained low temperature liquid CO2 circulates in the transcritical CO2 Rankine cycle module. The transcritical CO2 Rankine cycle module and the ammonia gas turbine module share a heat collector and flue gas low temperature regenerator.

[0029] Figure 1 The schematic diagram of the framework of the combined system of the ammonia cooling energy recovery gas turbine and CO2 Rankine cycle according to the embodiment of the present invention is as follows: Figure 1 The ammonia gas turbine module and the transcritical CO2 Rankine cycle module in the present invention are described in detail. It should be noted that: Figure 1 The solid lines in the figure represent the flow directions of ammonia, air, and flue gas, while the dotted lines represent the flow direction of CO2.

[0030] Specifically, Figure 1 As shown, the ammonia gas turbine module is provided with a first cooler 4, an ammonia preheater 5 and a combustion chamber 6 according to the flow direction of ammonia, wherein the first cooler 4 is used to vaporize liquid ammonia to release cold energy, and the ammonia preheater 5 is used to heat the vaporized ammonia to the ammonia combustible temperature. According to the flow direction of air, an air preheater 2 and a combustion chamber 6 are provided, wherein the air preheater 2 is used to heat the air, and the combustion chamber 6 is used to mix and burn the preheated ammonia and air in the combustion chamber 6 to generate flue gas and release heat. According to the flow direction of flue gas, an ammonia turbine 7, a heat extractor 8 and a flue gas low-temperature heat regenerator 10 are provided.

[0031] The transcritical CO2 Rankine cycle module is provided with a CO2 low-temperature regenerator 11, a high-temperature regenerator 12, a heat collector 8 and a CO2 turbine 13, wherein the CO2 low-temperature regenerator 11 and the flue gas low-temperature regenerator 10 are connected in parallel, and the transcritical CO2 Rankine cycle module and the ammonia gas turbine module share a heat collector 8.

[0032] According to the flow direction of low-temperature CO2, the flue gas low-temperature reheater 10 and the CO2 low-temperature reheater 11 are connected in parallel, and then connected to the high-temperature reheater 12 and the heat exchanger 8 in sequence to gradually heat the low-temperature CO2. The transcritical CO2 Rankine cycle module and the ammonia gas turbine module share a heat exchanger 8, and the low-temperature side CO2 is preheated by utilizing the primary waste heat of the flue gas in the heat exchanger 8. The preheated CO2 gas enters the CO2 turbine 13 to perform work and release high-temperature CO2 gas. According to the flow direction of the CO2 gas on the high temperature side, the outlet of the CO2 turbine 13 is connected in sequence with the hot side inlet of the high temperature regenerator 12 and the hot side inlet of the CO2 low temperature regenerator 11, and the hot side outlet of the CO2 low temperature regenerator 11 is connected with the hot side inlet of the first cooler 4, thereby exchanging heat with the low temperature side CO2 through the high temperature regenerator 12 and the CO2 low temperature regenerator 11, so that the CO2 on the low temperature side is heated while the CO2 gas on the high temperature side is cooled step by step to obtain the low temperature CO2 gas, and the cold energy released by the liquid ammonia recovered by the first cooler 4 is used to cool the low temperature CO2 gas to a temperature below the critical point, and the obtained low temperature liquid CO2 circulates in the transcritical CO2 Rankine cycle module.

[0033] In the embodiment of the present invention, the characteristics of ammonia being easy to prepare, low in cost, and pure ammonia not corroding metal parts are utilized, and the cold energy of ammonia is recovered by setting a first cooler in the flow direction of ammonia, and it is directly used in the CO2 Rankine cycle to liquefy the refluxed low-temperature CO2 gas. The preheated ammonia and air are burned in the combustion chamber, and the generated flue gas enters the ammonia turbine to expand and do work, outputting electrical energy and generating high-temperature flue gas waste heat. The heat collector is used as the coupling point between the ammonia gas turbine module and the transcritical CO2 Rankine cycle module, and the flue gas and CO2 gas are heat exchanged for the two modules respectively. In the flow direction of the flue gas, the primary waste heat of the flue gas in the heat collector is used to heat up the CO2 gas on the low-temperature side of the CO2 Rankine cycle module, and the secondary waste heat of the residual flue gas is used to preheat the air and ammonia respectively, so as to improve the combustion efficiency when the two are combined, and reduce the generation of NOx during the combustion of ammonia. The three-stage waste heat of the residual flue gas flows into the flue gas low-temperature regenerator, which can release heat to the liquid CO2 entering the flue gas low-temperature regenerator and gasify the liquid CO2 into CO2 gas. After the flue gas outputs electricity in the ammonia gas turbine, the structural design uses three-stage heat exchange to release the waste heat of the flue gas step by step, and comprehensively utilizes the energy of each part of the ammonia gas turbine module. After three-stage heat exchange, the flue gas temperature is finally reduced to near the dew point, the energy contained in the flue gas is efficiently converted, and the net efficiency of the cycle is improved.

[0034] In the CO2 flow direction on the low-temperature side, the flue gas low-temperature regenerator 10 and the CO2 low-temperature regenerator 11 are connected in parallel and then connected to the high-temperature regenerator 12 and the heat collector 8 in sequence for step-by-step temperature increase. The primary waste heat of the flue gas in the heat collector 8 is used to perform the primary temperature increase (i.e., the primary heat exchange of the flue gas) on the CO2 gas heated by the high-temperature regenerator 12. The heated CO2 gas enters the CO2 turbine 13 to expand and do work and release high-temperature CO2 gas. In the CO2 gas flow direction on the high-temperature side, by sequentially connecting the CO2 turbine 13, the high-temperature regenerator 12 and the CO2 low-temperature regenerator 11, the high-temperature CO2 gas is used to preheat the CO2 gas on the low-temperature side while cooling the CO2 gas on the high-temperature side step by step to obtain low-temperature CO2 gas. By using the tertiary waste heat of the flue gas as energy matching the gasification of liquid CO2 in the flue gas low-temperature regenerator and utilizing the split heat recovery method, the liquid CO2 and the low-temperature side CO2 gas are heated, thereby avoiding the power consumption generated by introducing the recompressor, and at the same time matching the temperature gradients on both sides near the low-temperature regenerator, thus solving the problem of pinch points that are easily generated at both ends of the regenerator. Then, the obtained low-temperature CO2 gas is transported to the first cooler 4, and the liquid ammonia refrigerant in the first cooler 4 is used to cool and liquefy the CO2 gas to obtain liquid CO2. The liquid CO2 can be recycled as the working fluid of the transcritical CO2 Rankine cycle module, which can achieve the purpose of zero carbon emissions and no pollution to the environment.

[0035] According to an embodiment of the present invention, continue as Figure 1 As shown, according to the flue gas flow direction, the hot side outlet of the heat collector 8 is connected to the hot side inlet of the air preheater 2 and the hot side inlet of the ammonia preheater 5, respectively, so as to use the secondary waste heat of the flue gas remaining in the heat collector 8 to preheat the air in the air preheater 2 and the ammonia in the ammonia preheater 5 (i.e., the secondary heat exchange of the flue gas), so that the ammonia reaches the ammonia combustible temperature (700-800°C) and preheat the air, thereby improving the combustion efficiency of the ammonia in the combustion chamber 6 and reducing the generation of NOx. By using the secondary waste heat of the flue gas to heat the air and ammonia, the potential utilization of the flue gas waste heat is realized. The hot side outlet of the air preheater 2 and the hot side outlet of the ammonia preheater 5 are connected to the hot side inlet of the flue gas low-temperature regenerator 10, so as to reheat the tertiary waste heat of the flue gas remaining in the air preheater 2 and the ammonia preheater 5 to the flue gas low-temperature regenerator 10, so as to utilize the energy in the subsequent CO2 Rankine cycle (i.e., the tertiary heat exchange of the flue gas). The hot side outlet of the flue gas low-temperature regenerator 10 is connected to the flue. After three-stage heat exchange, the temperature of the flue gas is reduced to near the dew point, which more efficiently converts the energy contained in the flue gas and discharges the flue gas with a lower temperature into the environment, reducing energy waste and thermal pollution to the environment.

[0036] According to an embodiment of the present invention, continue as Figure 1 As shown, in the direction of air flow, an air compressor 1 is also provided, the inlet of the air compressor 1 (CA) is connected to the external air storage tank, and the outlet of the air compressor 1 is connected to the cold side inlet of the air preheater 2. The air is introduced through the air compressor 1, compressed and the temperature of the air is preliminarily increased, and then the air enters the air preheater 2 for preheating after compression. The cold side outlets of the air preheater 2 are respectively connected to the combustion chamber 6, so that part of the preheated air is introduced into the combustion chamber 6 as an oxidant to catalyze the combustion of ammonia. The cold side outlet of the air preheater 2 is also connected to the pipeline between the combustion chamber 6 and the ammonia turbine 7, so that part of the air is mixed with the flue gas before flowing into the ammonia turbine 7, so as to adjust the temperature of the gas entering the ammonia turbine 7 and improve the net efficiency of the ammonia gas turbine. The remaining small amount of air can also be used as cooling air for turbine blades to reduce the temperature of the turbine and prevent turbine failure.

[0037] Ammonia has a large latent heat of phase change and is a natural refrigerant. It is often transported in liquid form during transportation. Therefore, a liquid ammonia pump 3 is also provided in the flow direction of ammonia. One end of the liquid ammonia pump 3 is connected to the liquid ammonia storage tank, and the other end is connected to the inlet of the first cooler 4. The liquid ammonia pump 3 is used to transport the liquid ammonia in the liquid ammonia storage tank to the first cooler 4. The liquid ammonia is pressurized by the liquid ammonia pump 3 and then transported to the first cooler 4 for heat exchange. A large amount of cold energy is released in the process of vaporizing liquid ammonia at -34°C into ammonia gas. This cold energy matches the cold energy required below the critical temperature (30.8°C) for converting CO2 gas into liquid CO2 in the transcritical CO2 Rankine cycle, thereby converting liquid ammonia into ammonia gas while liquefying CO2. Furthermore, the first cooler 4 is connected to the ammonia preheater 5, and the ammonia after heat exchange (heating) is passed into the ammonia preheater 5 for preheating. The preheated ammonia is passed into the combustion chamber 6 and mixed with the air entering the combustion chamber 6. The air acts as an oxidant to catalyze the combustion of ammonia, generating flue gas while releasing heat.

[0038] According to an embodiment of the present invention, a CO2 pump 9 (CO2 pump, PC) is further provided in the transcritical CO2 Rankine cycle module, one end of the CO2 pump 9 is connected to the first cooler 4, and the other end of the CO2 pump 9 is respectively connected to the flue gas low-temperature regenerator 10 and the CO2 low-temperature regenerator 11, for pressurizing and transporting external liquefied liquid CO2 and / or low-temperature liquid CO2 in the transcritical CO2 Rankine cycle to the flue gas low-temperature regenerator 10 and the CO2 low-temperature regenerator 11 for heat exchange.

[0039] Specifically, according to the flow direction of CO2 on the low-temperature side, one end of the CO2 pump 9 is connected to the first cooler 4, and the other end is connected to the flue gas low-temperature reheater 10 and the CO2 low-temperature reheater 11 respectively, so that the cooled liquid CO2 is transported to the flue gas low-temperature reheater 10 and the CO2 low-temperature reheater 11 through the CO2 pump 9 for three-stage heating, and the liquid CO2 is converted into CO2 gas. After the three-stage heating, the CO2 gases are merged and enter the high-temperature reheater 12 for two-stage heating. The CO2 gas after the two-stage heating enters the heat exchanger 8, and the low-temperature side CO2 (CO2 gas after the two-stage heating) is preheated by the first-stage waste heat of the flue gas in the heat exchanger 8. The preheated CO2 gas enters the CO2 turbine 13 to expand and do work, output electrical energy to the outside and release high-temperature CO2 gas.

[0040] In the flow direction of the CO2 gas on the high temperature side, the CO2 turbine 13 is connected to the hot side inlet of the high temperature regenerator 12, and the high temperature CO2 gas enters the high temperature regenerator 12 for primary heat recovery. After the primary heat recovery, the high temperature CO2 gas enters the CO2 low temperature regenerator 11 through the hot side inlet of the CO2 low temperature regenerator 11 for secondary heat recovery. The temperature of the CO2 gas on the high temperature side is gradually reduced through the primary heat recovery and the secondary heat recovery to obtain the low temperature CO2 gas. At the same time, energy is added to the liquid CO2 after the CO2 pump 9 to gasify it, realizing the energy utilization of the CO2 gas. After the low temperature CO2 gas is cooled in the first cooler 4, liquid CO2 is obtained, and the obtained liquid CO2 is transported by the CO2 pump 9 to circulate again in the CO2 Rankine cycle.

[0041] Furthermore, in order to avoid the problem of insufficient CO2 cooling in the transcritical CO2 Rankine cycle module and the first cooler 4, the combined system of the present invention also provides an ammonia refrigeration cycle module, including a throttle valve 16 (throttle valve, TV), a second cooler 17 (cool 2, C2), an ammonia compressor 14 (ammonia compressor, C-AM), and a condenser 15 (condenser, CD).

[0042] In the ammonia flow direction of the ammonia refrigeration cycle module, a closed loop consisting of a throttle valve 16, a second cooler 17, an ammonia compressor 14, and a condenser 15 is set. Among them, ammonia is connected to the pipeline between the throttle valve 16 and the cold side inlet of the second cooler 17, and the hot side inlet of the second cooler 17 is connected to the hot side outlet of the CO2 low-temperature regenerator 11, so as to further reduce the temperature of the CO2 gas by heat exchange with the low-temperature CO2 gas in the CO2 low-temperature regenerator 11. The cold outlet of the second cooler 17 is connected to the inlet of the CO2 pump 9, so that the cooled CO2 gas is discharged through the outlet of the second cooler 17, and mixed with the liquid CO2 cooled by the first cooler 4, and the mixed liquid CO2 enters the CO2 Rankine cycle module through the CO2 pump 9 for circulation. After the ammonia gas after heat exchange with the second cooler 17 enters the ammonia compressor for temperature and pressure increase, it enters the condenser 15.

[0043] According to an embodiment of the present invention, the cold inlet of the condenser 15 is connected to the outside air storage tank, so that the outside air is used as a coolant to liquefy the ammonia in the condenser, and at the same time, the excess heat is discharged into the air. The liquefied liquid ammonia flows back to the throttle valve 16 for repeated circulation.

[0044] Figure 2 This is a schematic diagram of the framework of a combined system of a gas turbine for recovering ammonia cold energy and a CO2 Rankine cycle in another embodiment of the present invention.

[0045] Figure 2 The structure and Figure 1 The structures are the same, and the functions of each unit are the same. The only difference is that the cold side inlet of the condenser 15 is connected to the external cooling water storage tank, and the hot side outlet of the condenser 15 is connected to the heating module; and the flue is connected to the hot side outlet of the flue gas low-temperature regenerator 10 through the heat exchanger 18, and the cold side inlet of the heat exchanger 18 is connected to the external cooling water, and the hot side outlet of the heat exchanger 18 is connected to the heating unit, wherein the cooling water can be heating return water. Therefore, the combined cycle system in the present invention changes from power generation to cogeneration, which can provide heating for the city, and according to the different temperatures of the cooling water (return water), the heat extracted from the condenser of the ammonia refrigeration cycle module can be used as the heating demand of the radiator, and the heat extracted from the flue gas discharged from the ammonia gas turbine module can be used for urban floor heating, as follows:

[0046] By introducing cooling water into the cooler 15 to exchange heat with the ammonia in the cooler 15, the ammonia is liquefied into liquid ammonia, and the hot water after heat exchange is discharged into the heating module through the hot side outlet of the condenser 15, which can be used for heating the radiator. The flue is connected to the flue gas low-temperature regenerator 10 through the heat exchanger 18, and the flue gas after the three-stage heat exchange is introduced into the heat exchanger 18 to exchange heat with the external cooling water entering through the cold end of the heat exchanger 18, further reducing the waste heat temperature of the flue gas, while increasing the temperature of the cooling water. The heated cooling water enters the heating unit for heating, wherein the heating unit can be a floor heating, that is, the floor heating is heated by the heated cooling water, further realizing the energy utilization of the flue gas, wherein the temperature of the flue gas after the three-stage heat exchange is 60-70°C to meet the temperature requirements of the floor heating.

[0047] As a second aspect of the present invention, a method for recovering ammonia cooling energy by combining a gas turbine with a CO2 Rankine cycle is provided, which uses the system in the above embodiment. Figure 1-Figure 2 This method is described in detail.

[0048] According to an embodiment of the present invention, a method for combining ammonia cold energy recovery gas turbine and CO2 Rankine cycle includes: after liquid ammonia is vaporized into ammonia and the cold energy of liquid ammonia is recovered, preheated air and ammonia are introduced into a combustion chamber 6 for combustion, flue gas is generated and heat is released, and the flue gas flows into an ammonia turbine 7 to perform work and output electrical energy and flue gas;

[0049] According to the flow direction of the flue gas, the primary waste heat of the flue gas is used to perform primary cooling in the heat extractor 8. After the primary cooling, the secondary waste heat of the flue gas is used to perform secondary cooling in the air preheater 2 and the ammonia preheater 5 respectively. After the secondary cooling, the tertiary waste heat of the flue gas is used to perform tertiary cooling in the flue gas low-temperature regenerator 10 to obtain low-temperature flue gas.

[0050] According to the flow direction of CO2 on the low-temperature side, the low-temperature liquid CO2 flows into the flue gas low-temperature regenerator 10 and the CO2 low-temperature regenerator 11 respectively for three-stage heating. The heated CO2 gas is combined and flows into the high-temperature regenerator 12 for two-stage heating, and enters the heat collector 8 for one-stage heating. The CO2 gas after step-by-step heating flows into the CO2 turbine 13 to perform work, output electrical energy and release high-temperature CO2 gas.

[0051] According to the flow direction of CO2 gas on the high-temperature side, the high-temperature CO2 gas flows back to the high-temperature regenerator 12 to perform primary heat recovery on the CO2 gas. The CO2 gas after the primary heat recovery flows back to the CO2 low-temperature regenerator 11 to perform secondary heat recovery on the low-temperature liquid CO2. The temperature of the CO2 gas on the high-temperature side is gradually reduced to obtain low-temperature CO2 gas. After the low-temperature CO2 gas is cooled to a temperature below the critical point by the cold energy recovered by the first cooler 4, the obtained low-temperature liquid CO2 circulates in the transcritical CO2 Rankine cycle module.

[0052] According to an embodiment of the present invention, air is transported to the air compressor 1 for compression and pressurization by using an air compressor 1, and the pressurized air is transported to the air preheater 2 for preheating; liquid ammonia is transported to the first cooler 4 for heat exchange by using a liquid ammonia pump 3, and the preheated ammonia flows into the ammonia preheater 5 for preheating.

[0053] In the embodiment of the present invention, the outside air is introduced and compressed by the air compressor 1, and then transported to the air preheater 2 for preheating, so as to increase the temperature of the air entering the combustion chamber 6, thereby improving the combustion rate and efficiency of the ammonia. The liquid ammonia from the outside is transported to the first cooler 4 through the liquid ammonia pump 3 to exchange heat with the CO2 gas, vaporizing the liquid ammonia into ammonia gas, and liquefying the CO2 gas into liquid CO2. The ammonia after heat exchange is transported to the ammonia preheater 5 for preheating, raising the temperature of the ammonia to the combustible temperature of the ammonia, so that the ammonia is fully preheated, and the generation of NOx pollutants is reduced when the ammonia is burned.

[0054] According to an embodiment of the present invention, before the flue gas enters the ammonia turbine 7, the preheated air is mixed with the flue gas to adjust the temperature of the gas entering the ammonia turbine 7. Specifically, the preheated air and ammonia are burned in the combustion chamber 6 to generate flue gas, and the flue gas enters the ammonia turbine 7 through the pipeline to expand and do work. Before the flue gas enters the ammonia turbine 7, part of the air is mixed with the flue gas to adjust the temperature of the gas entering the ammonia turbine 7, and also improve the partial net efficiency of the ammonia gas turbine. The remaining small amount of air is used as turbine blade cooling air to reduce the temperature of the turbine and prevent the ammonia turbine 7 from malfunctioning.

[0055] According to an embodiment of the present invention, the primary waste heat of the flue gas is utilized to perform primary cooling in the heat exchanger 8, that is, the primary waste heat of the flue gas is utilized to release heat to the CO2 gas in the heat exchanger 8; the secondary waste heat of the flue gas is utilized to perform secondary cooling in the air preheater 2 and the ammonia preheater 5, that is, after the primary cooling, the secondary waste heat of the flue gas is utilized to release heat to the air and ammonia respectively; the tertiary waste heat of the flue gas is utilized to perform tertiary cooling in the flue gas low-temperature regenerator 10, that is, after the secondary cooling, the tertiary waste heat of the flue gas is utilized to release heat to the liquid CO2 in the flue gas low-temperature regenerator 10.

[0056] According to the embodiment of the present invention, after the liquid CO2 is pressurized by the CO2 pump 9, it is divided into two streams and flows into the flue gas low-temperature regenerator 10 and the CO2 low-temperature regenerator 11, and the three-stage waste heat of the flue gas is introduced to make the heat source at both ends of the regenerator meet the heat matching requirements, avoiding the pinch point problem at both ends of the regenerator. The energy in the flue gas is gradually released through the three-stage heat release of the flue gas, so that the temperature of CO2 after the CO2 pump 9 is 40-60°C, and the flue gas temperature is reduced to near the dew point, which effectively reduces the flue gas emission temperature, reduces the thermal pollution to the environment, and improves the net efficiency of the cycle.

[0057] According to an embodiment of the present invention, liquid CO2 is introduced into the flue gas low-temperature regenerator 10, the CO2 low-temperature regenerator 11, the high-temperature regenerator 12 and the heat collector 8 for heat exchange, and the obtained high-temperature CO2 gas enters the CO2 turbine 13 for expansion and work, and the generated high-temperature CO2 gas continues to flow back to the high-temperature regenerator 12 and the CO2 low-temperature regenerator 11, and the low-temperature CO2 is preheated by the heat of the high-temperature CO2 gas, so that the energy of CO2 is recycled. Then, the low-temperature CO2 gas is liquefied into liquid CO2 by the first cooler 4, and circulated in the CO2 Rankine cycle, so as to achieve zero emission of CO2. In addition, by using the CO2 Rankine cycle module, the temperature of CO2 gas can be reduced, and then the CO2 gas can be liquefied into liquid CO2 by cooling it through the first cooler 4, thereby reducing the energy of cooling the liquefied liquid CO2 by the liquid ammonia phase change (first cooler), and reducing the power consumption of the ammonia refrigeration cycle module.

[0058] According to an embodiment of the present invention, one end of the second cooler 17 in the ammonia refrigeration cycle module is connected to the ammonia storage tank, and the other end is connected to the CO2 low-temperature regenerator 11, and the ammonia is introduced into the ammonia refrigeration cycle module. The ammonia exchanges heat with the low-temperature CO2 gas in the second cooler 17. The low-temperature CO2 gas is cooled into liquid CO2 and the ammonia is heated at the same time. The cooled liquid CO2 flows back to the CO2 pump 9 for circulation, and the preheated ammonia enters the condenser 15 for liquefaction, thereby solving the problem of insufficient CO2 cooling in the transcritical CO2 Rankine cycle module and the first cooler 4.

[0059] According to an embodiment of the present invention, air is introduced into the condenser 15, and the ammonia in the condenser 15 is liquefied by the air. The liquefied liquid ammonia circulates in the ammonia refrigeration cycle module through the throttle valve 16, and the heated air discharges heat to the outside.

[0060] According to an embodiment of the present invention, air is replaced with cooling water, that is, cooling water is introduced into the condenser, and the ammonia in the condenser is liquefied by the cooling water. The liquefied liquid ammonia circulates in the ammonia refrigeration cycle module, and the cooling water is heated at the same time. The heated cooling water is used for heating the radiator, wherein the cooling water can be the return water of the radiator.

[0061] According to an embodiment of the present invention, the flue gas of the exhaust system is directly introduced into the heat exchanger 18, and the external cooling water is used to exchange heat with the flue gas in the heat exchanger 18. The heated cooling water is used for floor heating, and the flue gas after heat exchange is discharged from the heat exchanger 18. In an embodiment of the present invention, a heat exchanger 18 (waste heat regenerator) is added to the outlet of the flue gas low-temperature regenerator 10, wherein the external cooling water can be floor heating return water, and can be used for urban floor heating.

[0062] According to an embodiment of the present invention, when the phase change cooling energy of liquid ammonia cannot meet the supplementary cooling demand of CO2, other refrigerants or other refrigeration forms can be used for cooling, such as absorption refrigeration, magnetic refrigeration and acoustic refrigeration. The number and position of the first cooler can be changed flexibly.

[0063] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A combined system of ammonia cooling energy recovery gas turbine and CO2 Rankine cycle, characterized in that: The system includes an ammonia gas turbine module and a transcritical CO2 Rankine cycle module; The ammonia gas turbine module is provided with a first cooler for vaporizing liquid ammonia to release cold energy, an ammonia preheater and a combustion chamber for heating the vaporized ammonia to a combustible temperature of the ammonia according to the flow direction of the ammonia; an air preheater and a combustion chamber are provided according to the flow direction of the air, and the ammonia and the air are mixed and burned in the combustion chamber to generate flue gas and release heat; an ammonia turbine, a heat extractor and a flue gas low-temperature heat regenerator are provided according to the flow direction of the flue gas; The transcritical CO2 Rankine cycle module is provided with a CO2 low-temperature regenerator, a high-temperature regenerator, a heat collector and a CO2 turbine, wherein the CO2 low-temperature regenerator and the flue gas low-temperature regenerator are connected in parallel, and the transcritical CO2 Rankine cycle module and the ammonia gas turbine module share a heat collector. According to the flow direction of CO2 on the low-temperature side, CO2 is preheated by passing through the CO2 low-temperature regenerator and the flue gas low-temperature regenerator respectively. The preheated CO2 gas is mixed and sequentially enters the high-temperature regenerator and the heat extractor for step-by-step temperature increase. The preheated CO2 gas enters the CO2 turbine to perform work and release high-temperature CO2 gas. According to the flow direction of the CO2 gas on the high-temperature side, the hot side outlet of the CO2 turbine is connected to the hot side inlet of the high-temperature regenerator and the hot side inlet of the CO2 low-temperature regenerator in sequence, and the hot side outlet of the CO2 low-temperature regenerator is connected to the hot side inlet of the first cooler, thereby gradually cooling the high-temperature side CO2 gas through the high-temperature regenerator and the CO2 low-temperature regenerator to obtain low-temperature CO2 gas, and the first cooler uses the cold energy released by recovering liquid ammonia to cool the low-temperature CO2 gas to a temperature below the critical point, and the obtained low-temperature liquid CO2 circulates in the transcritical CO2 Rankine cycle module.

2. The system according to claim 1, characterized in that The hot side outlet of the heat collector is connected to the hot side inlet of the ammonia preheater and the hot side inlet of the air preheater respectively. The hot side outlet of the air preheater and the hot side outlet of the ammonia preheater are connected to the hot side inlet of the flue gas low-temperature heat regenerator, and the hot side outlet of the flue gas low-temperature heat regenerator is connected to the flue.

3. The system according to claim 2, characterized in that An air compressor is also provided in the air flow direction, and the outlet of the air compressor is connected to the cold side inlet of the air preheater; The cold side outlet of the air preheater is connected to the combustion chamber, and the cold side outlet of the air preheater is also connected to the pipeline between the combustion chamber and the ammonia turbine; A liquid ammonia pump is also provided in the flow direction of the ammonia gas, one end of the liquid ammonia pump is connected to the liquid ammonia storage tank, and the other end is connected to the inlet of the first cooler. The liquid ammonia pump is used to pressurize the liquid ammonia in the liquid ammonia storage tank and transport it to the first cooler.

4. The system according to claim 3, characterized in that The transcritical CO2 Rankine cycle module is also provided with a CO2 pump, one end of which is connected to the first cooler, and the other end is respectively connected to the flue gas low-temperature regenerator and the CO2 low-temperature regenerator, and is used to pressurize and transport the external liquefied liquid CO2 and / or the low-temperature liquid CO2 in the transcritical CO2 Rankine cycle to the flue gas low-temperature regenerator and the CO2 low-temperature regenerator.

5. The system according to any one of claims 1 to 4, characterized in that: The system further comprises: an ammonia refrigeration cycle module, wherein a closed loop consisting of a throttle valve, a second cooler, an ammonia compressor and a condenser is provided in the ammonia flow direction of the ammonia refrigeration cycle module; Among them, the external ammonia storage tank is connected to the cold side inlet of the second cooler, the hot side inlet of the second cooler is also connected to the hot side outlet of the CO2 low-temperature regenerator, and the cold side outlet of the second cooler is connected to the inlet of the CO2 pump.

6. The system according to any one of claims 5, characterized in that The cold side inlet of the condenser is connected to an external air storage tank; or The cold side inlet of the condenser is connected to an external cooling water storage tank, and the hot side outlet of the condenser is connected to a heating module; and The flue is connected to the hot side outlet of the flue gas low-temperature heat regenerator through a heat exchanger, the cold side inlet of the heat exchanger is connected to external cooling water, and the hot side outlet of the heat exchanger is connected to a heating unit.

7. A method for recovering ammonia cooling energy by combining a gas turbine with a CO2 Rankine cycle, using the system described in any one of claims 1 to 6, characterized in that: The method comprises: After the liquid ammonia is vaporized into ammonia gas and the cold energy of the liquid ammonia is recovered, the preheated air and ammonia gas are introduced into the combustion chamber for combustion to generate flue gas and release heat, and the flue gas flows into the ammonia turbine to perform work and output electrical energy and flue gas; According to the flow direction of the flue gas, the primary waste heat of the flue gas is used to perform primary cooling in the heat extractor, and after the primary cooling, the secondary waste heat of the flue gas is used to perform secondary cooling in the air preheater and the ammonia preheater respectively, and after the secondary cooling, the tertiary waste heat of the flue gas is used to perform tertiary cooling in the flue gas low-temperature regenerator to obtain low-temperature flue gas; According to the flow direction of CO2 on the low-temperature side, the low-temperature liquid CO2 flows into the flue gas low-temperature regenerator and the CO2 low-temperature regenerator respectively for three-stage heating. The heated CO2 gas is combined and flows into the high-temperature regenerator for two-stage heating, and enters the heat collector for one-stage heating. The CO2 gas after step-by-step heating flows into the CO2 turbine to perform work, output electrical energy and release high-temperature CO2 gas. According to the flow direction of CO2 gas on the high-temperature side, the high-temperature CO2 gas flows back to the high-temperature regenerator to perform primary heat recovery on the CO2 gas, and the CO2 gas after the primary heat recovery flows back to the CO2 low-temperature regenerator to perform secondary heat recovery on the low-temperature liquid CO2, and the temperature of the CO2 gas on the high-temperature side is gradually reduced to obtain low-temperature CO2 gas. After the low-temperature CO2 gas is cooled to a temperature below the critical point by the cold energy recovered by the first cooler, the obtained low-temperature liquid CO2 circulates in the transcritical CO2 Rankine cycle module.

8. The method according to claim 7, characterized in that The air is transported to the air preheater by an air compressor and the liquid ammonia is transported to the first cooler by a liquid ammonia pump for heat exchange. The preheated ammonia flows into the ammonia preheater for preheating. Before the flue gas enters the ammonia turbine, the preheated air is mixed with the flue gas to adjust the temperature of the fuel gas entering the ammonia turbine.

9. The method according to claim 7, characterized in that: One end of the second cooler in the ammonia refrigeration cycle module is connected to the ammonia storage tank, and the other end is connected to the CO2 low-temperature regenerator, and ammonia is introduced into the ammonia refrigeration cycle module. The ammonia exchanges heat with the low-temperature CO2 gas in the second cooler. The low-temperature CO2 gas is cooled into liquid CO2 and heated at the same time. The cooled liquid CO2 gas flows back to the CO2 pump for circulation again.

10. The method according to claim 8, characterized in that Air is introduced into the condenser, and the ammonia in the condenser is liquefied by the air, the liquefied liquid ammonia circulates in the ammonia refrigeration cycle module, and the heated air is discharged to the outside; or Cooling water is introduced into the condenser, and the ammonia in the condenser is liquefied by the cooling water. The liquefied liquid ammonia circulates in the ammonia refrigeration cycle module, and the cooling water is heated at the same time. The heated cooling water is used for heating the radiator; as well as The flue gas discharged from the system is directly introduced into the heat exchanger, and external cooling water is used to exchange heat with the flue gas in the heat exchanger. The heated cooling water is used for floor heating, and the flue gas after heat exchange is discharged from the heat exchanger.

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