Power generation system for converting temperature difference into pressure energy

Abstract

The utility model discloses a power generation system utilizing temperature difference to convert pressure energy, which relates to the technical field of power generation equipment and comprises a secondary refrigerant circulating unit, a refrigerant circulating unit and a power generation unit. The secondary refrigerant circulating unit comprises a gasification heat exchanger, a cold storage heat exchanger and a first conveying pump, a refrigerant inlet of the gasification heat exchanger is used for receiving a cold source medium, and the cold storage heat exchanger comprises a shell, a condensation heat exchange pipe and a heat return heat exchange pipe; the refrigerant circulation unit comprises a pressure conversion tank, an evaporator, a first water tank and a second water tank, the power generation unit comprises a power generator and a prime motor used for driving the power generator to work, and the prime motor is further used for converting energy of water flowing out of the first water tank and energy of water flowing out of the second water tank into mechanical energy. By increasing the pressure of the low-pressure and low-temperature refrigerant in the pressure conversion tank, the first water tank and the second water tank alternately and circularly work, and the utilization efficiency of cold energy of the cold source medium and the power generation efficiency are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to power generation equipment technical field especially utilizes the power generation system of pressure energy of temperature difference conversion. BACKGROUND

[0002] Liquefied natural gas (LNG) low-temperature cold energy utilization technology is a new type of technology with energy-saving and environmental protection significance. As a clean energy, the cold energy generated in the process of gasification of liquefied natural gas into normal temperature natural gas is not fully utilized, and is usually directly discharged into the environment, causing great waste of energy. In the process of LNG cold energy utilization, the temperature difference driven power conversion method is a relatively efficient cold energy recovery technology, which can convert cold energy into mechanical energy or electrical energy, thereby improving energy utilization efficiency.

[0003] At present, some researches have explored the use of temperature difference between low-temperature fluid and external heat source to drive heat engine or expander to generate electricity, but most of these systems rely on complex organic working fluid Rankine cycle (ORC) or Stirling cycle, which has the problems of low heat exchange efficiency, high equipment cost and difficult maintenance. Therefore, how to utilize the temperature difference between LNG cold energy and external heat source to realize efficient cold energy recovery and power conversion, optimize the system structure, reduce the equipment cost and improve the operation reliability has become the key problem to be solved in the current LNG cold energy utilization technology. SUMMARY

[0004] The utility model aims at providing a kind of power generation system of pressure energy of temperature difference conversion to solve the problems existing in the prior art, improve the utilization efficiency of cold source medium cold energy.

[0005] To achieve the above object, the utility model provides the following scheme:

[0006] The utility model provides a kind of power generation system of pressure energy of temperature difference conversion, comprising:

[0007] The carrier refrigerant circulation unit includes a gasification heat exchanger, a cold storage heat exchanger and a first delivery pump. The cold medium inlet of the gasification heat exchanger is used to receive the cold source medium. The cold storage heat exchanger includes a shell, a condensation heat exchange pipe and a regenerative heat exchange pipe. The condensation heat exchange pipe and the regenerative heat exchange pipe are respectively arranged in the shell. The hot medium inlet of the gasification heat exchanger is communicated with the shell outlet of the cold storage heat exchanger through a first connecting pipe. The hot medium outlet of the gasification heat exchanger is communicated with the shell inlet of the cold storage heat exchanger through a second connecting pipe. The first delivery pump is arranged on the first connecting pipe or the second connecting pipe.

[0008] The refrigerant circulation unit comprises a pressure conversion tank, an evaporator, a first water tank and a second water tank, the outlet of the condensing heat exchange pipe is communicated with the inlet of the pressure conversion tank through a third connecting pipe, the outlet of the pressure conversion tank is communicated with the inlet of the regenerative heat exchange pipe through a fourth connecting pipe, the outlet of the regenerative heat exchange pipe is communicated with the refrigerant inlet of the evaporator through a fifth connecting pipe, the refrigerant outlets of the evaporator are respectively communicated with the gaseous refrigerant inlets of the first water tank and the second water tank and the gaseous refrigerant inlet of the pressure conversion tank, and the evaporator is used for vaporizing the refrigerant entering the evaporator by a heat source medium; the gaseous refrigerant outlets of the first water tank and the second water tank are respectively communicated with the inlets of the condensing heat exchange pipe.

[0009] The power generation unit comprises a generator and a prime mover used for driving the generator to work, and the prime mover is also used for converting the energy of the water flowing out of the first water tank and the water flowing out of the second water tank into mechanical energy.

[0010] Preferably, a cold storage tank is further included, the outlet of the condensing heat exchange pipe is communicated with the inlet of the cold storage tank, and the outlet of the cold storage tank is communicated with the pressure conversion tank through the third connecting pipe.

[0011] Preferably, a first valve is arranged on the third connecting pipe, and a seventh valve is arranged on the connecting pipe between the refrigerant outlet of the evaporator and the gaseous refrigerant inlet of the pressure conversion tank.

[0012] Preferably, the pipe wall of the condensing heat exchange pipe is in contact with the pipe wall of the regenerative heat exchange pipe.

[0013] Preferably, the shell side outlet of the cold storage heat exchanger is located at the same end of the condensing heat exchange pipe, the shell side inlet of the cold storage heat exchanger is located at the same end of the condensing heat exchange pipe, and the flow direction of the refrigerant in the cold storage heat exchanger is opposite to the flow direction of the refrigerant in the regenerative heat exchange pipe.

[0014] Preferably, the condensing heat exchange pipe and the regenerative heat exchange pipe both adopt coil pipes.

[0015] Preferably, the refrigerant circulation unit further comprises a second delivery pump and a second valve arranged on the fifth connecting pipe respectively.

[0016] Preferably, a low-pressure water tank is further included, the water outlets of the first water tank and the second water tank are respectively in sealed communication with the water inlets of the prime mover, the water outlet of the prime mover is in sealed communication with the water inlet of the low-pressure water tank, and the low-pressure water tank is in sealed communication with the water inlets of the first water tank and the second water tank respectively.

[0017] Preferably, the top end of the first water tank and the top end of the second water tank are both lower than the bottom end of the low-pressure water tank.

[0018] Preferably, a third valve is arranged on the gaseous refrigerant inlet of the first water tank, a fourth valve is arranged on the gaseous refrigerant outlet of the first water tank, a fifth valve is arranged on the gaseous refrigerant inlet of the second water tank, and a sixth valve is arranged on the gaseous refrigerant outlet of the second water tank.

[0019] The utility model discloses relative to prior art has obtained following technical effect:

[0020] The power generation system of the utility model utilizes temperature difference conversion pressure energy, and the cold energy of cold source medium (such as liquefied natural gas) is absorbed by the cooling medium, and the cold energy of cooling medium is absorbed by refrigerant in the cold storage heat exchanger, on one hand, the high-pressure gaseous refrigerant generated by the evaporator mixes with the low-pressure low-temperature refrigerant in the pressure conversion tank, to ensure that the low-pressure low-temperature refrigerant in the pressure conversion tank has sufficient pressure to enter the regenerative heat exchange pipe and evaporator in turn, improve the circulation efficiency of refrigerant, and further improve the heat exchange efficiency, that is, improve the utilization efficiency of cold energy of cold source medium, on the other hand, since no compressor or the like is used in the refrigerant circulation unit, if the refrigerant is in a supercritical state, it will not affect the normal operation of the system, so the refrigerant can be heated to a supercritical state, that is, a supercritical cycle is used, and the refrigerant in a supercritical state has higher heat exchange efficiency, further improving the utilization efficiency of cold energy of cold source medium and the overall operation efficiency of the system, on the other hand, the heat of heat source medium (such as boiler waste heat steam) can be used by the evaporator to make the refrigerant entering the evaporator gasify, the first water tank and the second water tank can alternately circulate to drive the prime mover, and further realize power generation by continuously using the cold energy of cold source medium and the heat energy of heat source medium, suitable for various industrial residual cold and heat scenes, and improve the utilization efficiency of cold energy of cold source medium and heat energy of heat source medium and power generation efficiency.

[0021] Further, in the cold storage heat exchanger, the flow directions of the cooling medium and the refrigerant are opposite, which meets the actual demand that the condensation temperature of the refrigerant in the condensation heat exchange pipe needs to be lower and lower during the flow process, so that the cooling medium can complete the condensation of the refrigerant during the flow process in the shell side, to maximize the recovery of the cold energy of cold source medium (such as liquefied natural gas), and further improve the heat exchange efficiency.

[0022] Further, the first delivery pump is used to realize the circulation of the cooling medium, the second delivery pump is used to realize the circulation of the refrigerant, the power required by the first delivery pump and the second delivery pump is small, the equipment cost and energy consumption are reduced, when the first delivery pump is arranged on the second connecting pipe, a low-temperature pump is not needed, when the second delivery pump is arranged on the fifth connecting pipe, a low-temperature pump is also not needed, and the equipment cost is further reduced.

[0023] Furthermore, methanol is used as the refrigerant. The refrigerant has a large temperature difference and strong cold storage capacity, so the required flow rate for refrigerant circulation is small, reducing energy consumption. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the power generation system of this utility model that utilizes temperature difference to convert pressure energy;

[0026] In the diagram: 1. Gasification heat exchanger; 2. First transfer pump; 3. Cold storage heat exchanger; 4. Cold storage tank; 5. Second transfer pump; 6. Pressure conversion tank; 7. Evaporator; 8. First water tank; 9. Water turbine; 10. Low-pressure water tank; 11. Second water tank; 12. First valve; 13. Seventh valve; 14. Second valve. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] The purpose of this invention is to provide a power generation system that utilizes temperature difference to convert pressure energy, thereby solving the problems existing in the prior art and improving the utilization efficiency of cold energy in the cold source medium.

[0029] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1 As shown, this embodiment provides a power generation system that utilizes temperature difference to convert pressure energy, including:

[0031] The refrigerant circulating unit comprises a gasification heat exchanger 1, a cold storage heat exchanger 3 and a first delivery pump 2, the refrigerant inlet of the gasification heat exchanger 1 is used for receiving the cold source medium, the cold storage heat exchanger 3 comprises a shell, a condensation heat exchange pipe and a regenerative heat exchange pipe, the condensation heat exchange pipe and the regenerative heat exchange pipe are arranged in the shell respectively, the heat medium inlet of the gasification heat exchanger 1 is communicated with the shell outlet of the cold storage heat exchanger 3 through a first connecting pipe, the heat medium outlet of the gasification heat exchanger 1 is communicated with the shell inlet of the cold storage heat exchanger 3 through a second connecting pipe, and the first delivery pump 2 is arranged on the first connecting pipe or the second connecting pipe.

[0032] The refrigerant circulating unit comprises a gasification heat exchanger 1, a cold storage heat exchanger 3 and a first delivery pump 2, the refrigerant inlet of the gasification heat exchanger 1 is used for receiving the cold source medium, the cold storage heat exchanger 3 comprises a shell, a condensation heat exchange pipe and a regenerative heat exchange pipe, the condensation heat exchange pipe and the regenerative heat exchange pipe are arranged in the shell respectively, the heat medium inlet of the gasification heat exchanger 1 is communicated with the shell outlet of the cold storage heat exchanger 3 through a first connecting pipe, the heat medium outlet of the gasification heat exchanger 1 is communicated with the shell inlet of the cold storage heat exchanger 3 through a second connecting pipe, and the first delivery pump 2 is arranged on the first connecting pipe or the second connecting pipe.

[0033] The power generation unit comprises a generator and a prime mover for driving the generator to work, and in the embodiment, the prime mover is a water turbine 9, and the water flowing out of the first water tank 8 and the water flowing out of the second water tank 11 are used for driving the runner of the water turbine 9 to rotate.

[0034] It is worth noting that the refrigerant outlet of the pressure conversion tank 6 is arranged at the bottom, and the gaseous refrigerant inlet is arranged at the top, so that the refrigerant in the pressure conversion tank 6 can quickly flow into the regenerative heat exchange pipe under the pressure of the high-pressure gaseous refrigerant at the top. In the embodiment, the cold source medium can be liquefied natural gas, but is not limited to liquefied natural gas. The cold source medium can also be low-temperature waste gas in industrial production, low-temperature seawater in the seawater desalination process and other media containing cold energy. Similarly, the heat source medium can be boiler waste heat steam, but is not limited to boiler waste heat steam. The heat source medium can also be high-temperature waste gas, high-temperature waste water and other media rich in heat energy in the industrial production process. In actual application, the prime mover is not limited to the water turbine 9. That is, in addition to the water turbine 9, the prime mover can also be a hydraulic turbine (such as a nozzle type, a centrifugal type or other non-traditional structures) according to the system working condition, so as to adapt to the needs of different pressures, flow rates and energy recovery efficiencies.

[0035] In the optional solution of the embodiment, preferably, the condensing heat exchange pipe is in communication with the inlet of the cold storage tank 4, and the outlet of the cold storage tank 4 is in communication with the pressure conversion tank 6 through a third connecting pipe; the cold storage tank 4 is used for temporarily storing the low-temperature refrigerant after condensation.

[0036] In the optional solution of the embodiment, preferably, the third connecting pipe is provided with a first valve 12, and whether the refrigerant in the cold storage tank 4 flows into the pressure conversion tank 6 can be controlled by opening and closing the first valve 12; the communication pipe between the outlet of the evaporator 7 and the gaseous refrigerant inlet of the pressure conversion tank 6 is provided with a seventh valve 13, and whether the high-pressure gaseous refrigerant in the evaporator 7 flows into the pressure conversion tank 6 can be controlled by opening and closing the seventh valve 13.

[0037] In the optional solution of the embodiment, preferably, the wall of the condensing heat exchange pipe is in contact with the wall of the regenerative heat exchange pipe, so that the refrigerant in the regenerative heat exchange pipe can exchange heat not only with the cold carrier in the shell side but also with the refrigerant in the condensing heat exchange pipe, thereby improving the preheating efficiency of the refrigerant in the regenerative heat exchange pipe.

[0038] In the optional solution of the embodiment, preferably, the outlet of the shell side of the cold storage heat exchanger 3 and the inlet of the condensing heat exchange pipe are located at the same end of the cold storage heat exchanger 3, and the inlet of the shell side of the cold storage heat exchanger 3 and the outlet of the condensing heat exchange pipe are located at the same end of the cold storage heat exchanger 3, so that the flow directions of the cold carrier and the refrigerant are opposite, which meets the actual requirement that the condensing temperature of the refrigerant needs to be lower and lower during the process of flowing from the inlet of the condensing heat exchange pipe to the outlet of the condensing heat exchange pipe, while the temperature of the cold carrier gradually increases during the process of flowing from the inlet of the shell side of the cold storage heat exchanger 3 to the outlet of the shell side of the cold storage heat exchanger 3, so that the cold carrier can complete the condensation of the refrigerant during the flow process in the shell side, so as to maximize the recovery of the cold energy of the cold source medium (such as liquefied natural gas), thereby improving the heat exchange efficiency; the flow direction of the refrigerant in the cold storage heat exchanger 3 is opposite to the flow direction of the refrigerant in the regenerative heat exchange pipe, so that the refrigerant in the regenerative heat exchange pipe can be better preheated.

[0039] In the optional solution of the embodiment, preferably, the condensing heat exchange pipe and the regenerative heat exchange pipe both adopt coil pipes; the curved shape of the coil pipe can increase the length of the heat exchange pipe in a limited space, thereby increasing the heat exchange area. More heat exchange area means that heat exchange can be more fully carried out, thereby improving the condensing or regenerative efficiency.

[0040] In the alternative of the embodiment, preferably, the refrigerant circulating unit further comprises a second delivery pump 5 and a second valve 14 arranged on the fifth connecting pipe respectively, the second delivery pump 5 is arranged for the reason that the refrigerant in the evaporator 7 has high pressure after being vaporized, so the refrigerant in the regenerative heat exchange pipe needs to be pumped into the evaporator 7 by the operation of the second delivery pump 5 to ensure the stable operation of the refrigerant circulating unit.

[0041] In the alternative of the embodiment, preferably, the low-pressure water tank 10 is further included, the water outlet of the first water tank 8 and the water outlet of the second water tank 11 are in sealed communication with the water inlet of the water turbine 9 respectively, the water outlet of the water turbine 9 is in sealed communication with the water inlet of the low-pressure water tank 10, and the low-pressure water tank 10 is in sealed communication with the water inlet of the first water tank 8 and the water inlet of the second water tank 11 respectively; it is to be noted that the above-mentioned sealed communication is arranged for the reason that the water in the first water tank 8 or the water in the second water tank 11 can flow into the low-pressure water tank 10 with sufficient pressure under the premise of no pressure relief when the water flows out under high pressure.

[0042] In the embodiment, the top end of the first water tank 8 and the top end of the second water tank 11 are lower than the bottom end of the low-pressure water tank 10, and such arrangement can facilitate the water in the low-pressure water tank 10 to flow to the first water tank 8 and the second water tank 11 under the action of gravity, so as to reduce energy consumption.

[0043] In the embodiment, the gaseous refrigerant inlet of the first water tank 8 is provided with a third valve, the gaseous refrigerant outlet of the first water tank 8 is provided with a fourth valve, the gaseous refrigerant inlet of the second water tank 11 is provided with a fifth valve, and the gaseous refrigerant outlet of the second water tank 11 is provided with a sixth valve. The third valve, the fourth valve, the fifth valve and the sixth valve are arranged to facilitate the control of switching the processes of air intake and water discharge and water intake and air discharge of the first water tank 8 and the second water tank 11, so as to facilitate the use; specifically:

[0044] When the air intake and water discharge of the first water tank 8 is needed, the third valve is opened and the fourth valve is closed, after the high-pressure gaseous refrigerant enters the first water tank 8, the water in the first water tank 8 is driven to flow to the water turbine 9, thereby driving the water turbine 9 to work, and the water turbine 9 drives the generator to generate electricity, while when the water intake and air discharge of the first water tank 8 is needed, the third valve is closed and the fourth valve is opened, the high-pressure gaseous refrigerant in the first water tank 8 slowly flows to the condensing heat exchange pipe, and at the same time, the water in the low-pressure water tank 10 flows into the first water tank 8 under the action of gravity to supplement the water in the first water tank 8;

[0045] Similarly, when the second water tank 11 needs to be filled with air and drained, the fifth valve is opened and the sixth valve is closed, and after the high-pressure gaseous refrigerant enters the second water tank 11, the water in the second water tank 11 is driven to flow to the water turbine 9, thereby driving the water turbine 9 to work, and the water turbine 9 drives the generator to generate electricity. When the second water tank 11 needs to be filled with water and drained, the fifth valve is closed and the sixth valve is opened, and the high-pressure gaseous refrigerant in the second water tank 11 slowly flows to the condensing heat exchange pipe, and at the same time, the water in the low-pressure water tank 10 flows into the second water tank 11 under the action of gravity, thereby supplementing the water in the second water tank 11.

[0046] The specific use method of the power generation system utilizing temperature difference conversion pressure energy in the embodiment is as follows:

[0047] The cold source medium exchanges heat with the cold carrier (such as methanol) in the gasification heat exchanger 1, releases cold energy to cool the cold carrier, and the cooled cold carrier flows back to the bottom of the cold storage heat exchanger 3. In the cold storage heat exchanger 3, the cold carrier in the shell side exchanges heat with the refrigerant (such as ethylene) in the condensing heat exchange pipe to transfer cold energy, so that the refrigerant in the condensing heat exchange pipe is condensed into liquid state.

[0048] After the refrigerant in the condensing heat exchange pipe is condensed into liquid state low-pressure liquid refrigerant, the low-pressure liquid refrigerant flows into the cold storage tank 4, the first valve 12 is opened and the seventh valve 13 and the second valve 14 are closed, and the low-pressure liquid refrigerant in the cold storage tank 4 can flow into the pressure conversion tank 6. The cold storage tank 4 is used for temporarily storing low-temperature liquid refrigerant, and after the pressure conversion tank 6 has sufficient low-temperature liquid refrigerant, the second valve 14 and the seventh valve 13 are opened and the first valve 12 is closed, so as to increase the pressure of the refrigerant in the pressure conversion tank 6 and ensure that it has sufficient pressure to enter the regenerative heat exchange pipe and the evaporator 7. The high-pressure low-temperature refrigerant in the pressure conversion tank 6 is first preheated by absorbing part of the heat in the regenerative heat exchange pipe, and then enters the evaporator 7 under the action of the second delivery pump 5 after increasing its enthalpy. The high-pressure low-temperature refrigerant absorbs the heat of the heat source medium in the evaporator 7 and is gasified to form high-pressure gaseous refrigerant.

[0049] The high-pressure gaseous refrigerant formed in the evaporator 7 enters the first water tank 8 or the second water tank 11. When the first water tank 8 is filled with air and drained, the second water tank 11 is filled with water and drained. When the first water tank 8 is filled with water and drained, the second water tank 11 is filled with air and drained.

[0050] Taking the first water tank 8 as an example, the first water tank 8 is filled with air and drained, and the second water tank 11 is filled with water and drained.

[0051] The high-pressure gaseous refrigerant formed in the evaporator 7 enters the first water tank 8 to apply pressure to the water in the first water tank 8, and the water in the first water tank 8 flows into the water turbine 9 to drive the runner of the water turbine 9 to rotate, and the water turbine 9 drives the generator to rotate, so that the generator generates electricity, and the water after work is discharged into the low-pressure water tank 10 through the pipeline; at the same time, the fifth valve is closed and the sixth valve is opened, and the high-pressure gaseous refrigerant in the second water tank 11 slowly flows into the condensing heat exchange pipe, and the water in the low-pressure water tank 10 flows into the second water tank 11 under the action of gravity to supplement the water in the second water tank 11, and the water in the low-pressure water tank 10 entering the second water tank 11 can also push the high-pressure refrigerant gas in the second water tank 11 to be discharged into the cold storage heat exchanger 3 to be condensed into low-pressure liquid, so that the pressure of the gaseous refrigerant in the second water tank 11 gradually decreases, and when the water level in the second water tank 11 reaches the highest, switching is performed, so that the first water tank 8 performs water intake and exhaust, and the second water tank 11 performs gas intake and water discharge;

[0052] The process of the first water tank 8 performing water intake and exhaust and the second water tank 11 performing gas intake and water discharge is as follows:

[0053] The high-pressure gaseous refrigerant formed in the evaporator 7 enters the second water tank 11 to apply pressure to the water in the second water tank 11, and the water in the second water tank 11 flows into the water turbine 9 to drive the runner of the water turbine 9 to rotate, and the water turbine 9 drives the generator to rotate, so that the generator generates electricity, and the water after work is discharged into the low-pressure water tank 10 through the pipeline; at the same time, the third valve is closed and the fourth valve is opened, and the high-pressure gaseous refrigerant in the first water tank 8 slowly flows into the condensing heat exchange pipe, and the water in the low-pressure water tank 10 flows into the first water tank 8 under the action of gravity to supplement the water in the first water tank 8, and the water in the low-pressure water tank 10 entering the first water tank 8 can also push the high-pressure refrigerant gas in the first water tank 8 to be discharged into the cold storage heat exchanger 3 to be condensed into low-pressure liquid, so that the pressure of the gaseous refrigerant in the first water tank 8 gradually decreases, and when the water level in the first water tank 8 reaches the highest, switching is performed, so that the first water tank 8 performs gas intake and water discharge, and the second water tank 11 performs water intake and exhaust;

[0054] In this way, the system is continuously switched between the first state (the first water tank 8 performs gas intake and water discharge and the second water tank 11 performs water intake and exhaust) and the second state (the first water tank 8 performs water intake and exhaust and the second water tank 11 performs gas intake and water discharge), so that the first state and the second state are alternately performed, the water turbine 9 is continuously driven to rotate to drive the generator to generate electricity, the utilization efficiency of the cold energy of the cold source medium and the heat energy of the heat source medium and the power generation efficiency are improved, and the power output is more stable, the problem of impact load that may occur in a single expander system is avoided, and the stability and service life of the water turbine 9 are improved. The system optimizes the entire refrigerant circulation, makes the switching of heat exchange, pressure conversion and water turbine 9 working fluid more efficient, and ensures long-term stable operation of the system.

[0055] The power generation system of the embodiment utilizes temperature difference conversion pressure energy, and the utilization rate of LNG cold energy is improved by innovatively designing a cold energy recovery path and a power conversion structure, and energy waste is reduced.

[0056] The principle and implementation mode of the utility model are described by applying specific examples in the utility model, and the above embodiment is only used for helping to understand the method and core idea of the utility model; meanwhile, for the general technical personnel in the field, the specific implementation mode and application range will be changed according to the idea of the utility model. In conclusion, the content of the specification should not be understood as the limitation of the utility model.

Claims

1. A power generation system that converts pressure energy using temperature difference, characterized by, include: A refrigerant circulation unit includes a vaporization heat exchanger, a cold storage heat exchanger, and a first delivery pump. The refrigerant inlet of the vaporization heat exchanger is used to receive a cold source medium. The cold storage heat exchanger includes a shell, a condensation heat exchange tube, and a regeneration heat exchange tube. The condensation heat exchange tube and the regeneration heat exchange tube are respectively disposed in the shell. The heat medium inlet of the vaporization heat exchanger is connected to the shell-side outlet of the cold storage heat exchanger through a first connecting pipe. The heat medium outlet of the vaporization heat exchanger is connected to the shell-side inlet of the cold storage heat exchanger through a second connecting pipe. The first delivery pump is disposed on the first connecting pipe or the second connecting pipe. The refrigerant circulation unit includes a pressure conversion tank, an evaporator, a first water tank, and a second water tank. The outlet of the condenser heat exchanger tube is connected to the inlet of the pressure conversion tank via a third connecting pipe. The outlet of the pressure conversion tank is connected to the inlet of the regenerative heat exchanger tube via a fourth connecting pipe. The outlet of the regenerative heat exchanger tube is connected to the refrigerant inlet of the evaporator via a fifth connecting pipe. The refrigerant outlet of the evaporator is connected to the gaseous refrigerant inlets of the first water tank, the second water tank, and the pressure conversion tank, respectively. The evaporator is used to vaporize the refrigerant entering the evaporator through a heat source medium. The gaseous refrigerant outlets of the first and second water tanks are respectively connected to the inlet of the condenser heat exchanger tube. The power generation unit includes a generator and a prime mover for driving the generator, the prime mover also being used to convert the energy of water flowing from the first water tank and water flowing from the second water tank into mechanical energy.

2. The power generation system utilizing temperature difference conversion pressure energy according to claim 1, characterized by: It also includes a cold storage tank, the outlet of the condenser heat exchange tube is connected to the inlet of the cold storage tank, and the outlet of the cold storage tank is connected to the pressure conversion tank through the third connecting pipe.

3. The power generation system utilizing temperature difference conversion pressure energy according to claim 2, characterized by: A first valve is installed on the third connecting pipe; a seventh valve is installed on the connecting pipe between the refrigerant outlet of the evaporator and the gaseous refrigerant inlet of the pressure conversion tank.

4. The power generation system utilizing temperature difference conversion pressure energy according to claim 1, characterized by: The wall of the condenser heat exchanger tube is in contact with the wall of the regenerative heat exchanger tube.

5. The power generation system utilizing temperature difference conversion pressure energy according to claim 1, characterized by: The shell-side outlet of the cold storage heat exchanger and the inlet of the condenser heat exchange tube are located at the same end of the cold storage heat exchanger, and the shell-side inlet of the cold storage heat exchanger and the outlet of the condenser heat exchange tube are located at the same end of the cold storage heat exchanger; the flow direction of the refrigerant in the cold storage heat exchanger is opposite to the flow direction of the refrigerant in the regenerative heat exchange tube.

6. The power generation system utilizing temperature difference conversion pressure energy according to claim 1, characterized by: Both the condenser heat exchanger tube and the regenerator heat exchanger tube are coiled.

7. The power generation system utilizing temperature difference conversion pressure energy according to claim 1, characterized by: The refrigerant circulation unit also includes a second delivery pump and a second valve respectively installed on the fifth connecting pipe.

8. The power generation system utilizing temperature difference conversion pressure energy according to claim 1, characterized by: It also includes a low-pressure water tank, wherein the outlets of the first water tank and the second water tank are respectively sealed and connected to the inlet of the prime mover, the outlet of the prime mover is sealed and connected to the inlet of the low-pressure water tank, and the low-pressure water tank is sealed and connected to the inlet of the first water tank and the inlet of the second water tank.

9. The power generation system utilizing temperature difference conversion pressure energy according to claim 8, characterized by: The top of the first water tank and the top of the second water tank are both lower than the bottom of the low-pressure water tank.

10. The power generation system utilizing temperature difference conversion pressure energy according to claim 1, characterized by: A third valve is arranged on the gaseous refrigerant inlet of the first water tank, a fourth valve is arranged on the gaseous refrigerant outlet of the first water tank, a fifth valve is arranged on the gaseous refrigerant inlet of the second water tank, and a sixth valve is arranged on the gaseous refrigerant outlet of the second water tank.

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