Natural cold energy storage and conversion utilization system and method

Abstract

The invention relates to the technical field of renewable energy and cold energy utilization, and discloses a natural cold energy storage and conversion utilization system and method.The natural cold energy storage and conversion utilization system comprises a freeze concentration module, a solution storage module, a solution energy release module, a reverse electrodialysis energy release module and a reverse osmosis energy storage and release module; a dilute solution is frozen and concentrated through the freeze concentration module and then separated to obtain ice and a concentrated solution, the ice and the concentrated solution are stored in the solution storage module, and when low-price electric energy exists, the dilute solution is subjected to concentration energy storage through the reverse osmosis energy storage and release module; when electric power is needed, energy release operation is carried out through the solution energy release module, the reverse electrodialysis energy release module or the reverse osmosis energy storage and release module, and energy stored in ice and concentrated solution is converted into electric power to be output. In order to overcome the defects of the current energy storage technology, the natural cold energy cross-seasonal storage system based on the solution is designed, natural cold energy can be converted into electric energy to be output, and a novel renewable energy source utilization system is provided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of renewable energy and cold energy utilization, and particularly relates to a natural cold energy storage and conversion utilization system and method. BACKGROUND

[0002] To solve the problems of atmospheric pollution and greenhouse effect caused by the development and utilization of traditional fossil energy, clean and renewable energy technologies such as solar energy and wind energy have developed rapidly. However, solar energy and wind energy are free and renewable, but they have the disadvantages of instability and low energy density, and need to be combined with energy storage systems to obtain better economic and technical effects. The currently widely used electric energy storage technologies include pumped storage, compressed (liquefied) air energy storage, electrochemical energy storage, gravity energy storage, and flywheel energy storage, which mainly convert electric power into potential energy, chemical energy, etc. for storage, and convert them into electric power for output when needed, and cannot be directly used to store thermal energy or convert thermal energy (or cold energy) into electric energy for storage. However, the volume of air and other media in nature is huge, and its temperature changes regularly, which contains considerable thermal energy or cold energy that can be utilized. However, due to the constraints of time and space, air is currently mainly used as a low-temperature heat source for heat pumps to provide low-grade heat energy for house heating and material heating, or as a high-temperature heat source for heat pumps to provide a heat sink for house cooling and material cooling. There is still a lack of technical means to generate electricity using the thermal energy (cold energy) of air itself rather than kinetic energy or potential energy. On the other hand, the temperature of solar photovoltaic cells increases during power generation, and the photoelectric conversion efficiency decreases with the increase of temperature. Therefore, providing effective cooling measures for photovoltaic cells can improve the photoelectric conversion efficiency and the efficiency of solar photovoltaic power generation. However, the current electric energy storage technologies cannot play a synergistic role for this purpose.

[0003] In the prior art, natural cold sources are often used directly and simply. For example, the natural cold source cold storage system with the invention number CN109442799A utilizes the low outdoor temperature in winter night to cool the cooling water and store the cold energy in the water storage unit, so as to provide a cold source for chilled water during the daytime when the temperature is relatively high.

[0004] In recent years, an energy conversion and utilization technology using the concentration difference of solution has appeared. The electric energy can be stored in the form of chemical energy by concentrating the solution, and the stored chemical energy can be converted into electric power output through processes such as pressure retarded osmosis (PRO) or reverse electrodialysis when needed. By utilizing the physical and chemical properties of the solution, it is possible to convert and store energy using natural cold energy, and to provide cooling for solar cells, thereby developing a new type of renewable energy power generation system and technology. SUMMARY

[0005] The technical problem solved by the present application is to provide a natural cold energy storage and conversion system and method, which converts natural cold energy into concentrated solution and ice for cross-seasonal storage, provides cooling for photovoltaic cells when electricity is needed, and further converts the chemical energy stored in the concentrated solution into electrical energy output through PRO or reverse electrodialysis process, while also storing electricity through solution concentration at night or when electricity is abundant, and releasing the stored electrical energy in the concentrated solution during peak electricity consumption.

[0006] To solve the above technical problems, the present application provides a natural cold energy storage and conversion system, comprising a freezing and concentration module and a solution storage module.

[0007] The freezing and concentration module comprises a solution separator, a spray tower and a fan connected in sequence from bottom to top; a spray liquid distributor is arranged at the top of the spray tower.

[0008] The solution storage module comprises a dilute solution storage tank, an ice slurry storage tank and a concentrated solution storage tank; the dilute solution outlet of the dilute solution storage tank is connected to the ice slurry outlet of the solution separator through a pipeline after a solution filter, a first solution pump, an ice slurry pump, an ice slurry separator and a second solution pump, and then connected to the spray liquid distributor; the inlet of the ice slurry storage tank is connected to the ice slurry outlet of the ice slurry separator; the concentrated solution inlet of the concentrated solution storage tank is connected to the solution outlet of the solution separator through a concentrated solution pump.

[0009] The solution storage module is connected to a solution energy release module; the solution energy release module comprises a hydraulic turbine generator and a permeation membrane; the concentrated solution outlet of the concentrated solution storage tank is divided into two paths after passing through a concentrated solution feed pump, a first concentrated solution filter, a low-pressure side passage of a pressure exchanger, a concentrated solution booster pump, a second concentrated solution filter and a concentrated side passage of the permeation membrane, one path is connected to the dilute solution inlet of the dilute solution storage tank through the hydraulic turbine generator, and the other path is connected to the dilute solution inlet of the dilute solution storage tank through a high-pressure side passage of the pressure exchanger; the dilute side passage of the permeation membrane is connected to the outlet of the ice slurry storage tank through a dilute water filter and a dilute water pump.

[0010] The solution storage module is connected to a reverse electrodialysis energy release module; the reverse electrodialysis energy release module comprises a concentrated chamber and a dilute chamber arranged at intervals; the concentrated solution outlet of the concentrated solution storage tank is connected to the inlet of the concentrated chamber through a concentrated solution feed pump and a first concentrated solution filter; the outlet of the ice slurry storage tank is connected to the inlet of the dilute chamber through a dilute water pump and a dilute water filter; the outlets of the concentrated chamber and the dilute chamber are both connected to the inlet of the dilute solution storage tank.

[0011] The present application also provides a second natural cold energy storage and conversion system, comprising a freezing and concentration module, a solution storage module and a reverse osmosis energy storage and release module.

[0012] The freezing concentration module comprises, from bottom to top, a solution separator, a spray tower and a fan; a spray liquid distributor is arranged at the top of the spray tower;

[0013] The solution storage module comprises a dilute solution storage tank, an ice slurry storage tank and a concentrated solution storage tank; the dilute solution outlet of the dilute solution storage tank is connected to the ice slurry outlet of the solution separator through a pipeline after a solution filter, a first solution pump and a second solution pump, and then connected to the spray liquid distributor; the ice slurry storage tank is connected to the ice slurry outlet of the ice slurry separator; the concentrated solution storage tank is connected to the solution outlet of the solution separator through a concentrated solution pump;

[0014] The reverse osmosis energy storage and release module comprises a photovoltaic power generation panel, a hydraulic turbine generator and an osmosis membrane; the dilute solution outlet of the dilute solution storage tank is divided into two parallel pipelines after passing through a seventh switch valve, a concentrated solution feed pump, a first concentrated solution filter and a low-pressure side passage of a pressure exchanger; one pipeline passes through a fifteenth switch valve and a first concentrated solution booster pump, and the other pipeline passes through a sixteenth switch valve and a second concentrated solution booster pump; then, the two pipelines are combined into one pipeline, which is connected to the concentrated side passage inlet of the osmosis membrane through a second concentrated solution filter; the outlet of the concentrated side passage of the osmosis membrane is divided into two pipelines; one pipeline is connected to the inlet of the dilute solution storage tank after passing through a fourteenth switch valve and a hydraulic turbine generator, and the other pipeline is divided into two pipelines after passing through an eleventh switch valve and a high-pressure side passage of a pressure exchanger; one pipeline is connected to the inlet of the dilute solution storage tank after passing through a thirteenth switch valve, and the other pipeline is connected to the inlet of the concentrated solution storage tank through an eighth switch valve;

[0015] The outlet of the concentrated solution storage tank is connected to the inlet of the concentrated solution feed pump through a sixth switch valve, and the outlet of the ice slurry storage tank is connected to the inlet of the ice slurry storage tank through a third switch valve after passing through a cold water pump, a cooling passage of a photovoltaic power generation panel and a cold water filter.

[0016] As an improvement of the natural cold energy storage and conversion system of the application:

[0017] The connection between the solution separator and the spray tower and the connection between the spray tower and the fan are any of the following schemes:

[0018] Scheme one: an air filter is arranged between the solution separator and the spray tower, and a heat exchanger is arranged between the fan and the spray tower; the first solution pump and the second solution pump are connected to the spray liquid distributor after passing through the heat exchanger;

[0019] Scheme two: the solution separator and the spray tower are directly connected, and a heat exchanger is arranged between the fan and the spray tower; the first solution pump and the second solution pump are connected to the spray liquid distributor after passing through the heat exchanger;

[0020] Scheme three: an air filter is arranged between the solution separator and the spray tower, and the fan is directly connected with the spray tower.

[0021] The application provides a use method of a natural cold energy storage and conversion system, and the use method comprises the following steps:

[0022] In cold weather, the dilute solution is frozen and concentrated by a freezing and concentrating module to obtain ice and concentrated solution, the ice is stored in an ice slurry storage tank, and the concentrated solution is stored in a concentrated solution storage tank; when power is needed, energy stored in the ice and the concentrated solution is converted into power output through energy release operation of a solution energy release module or through energy release operation of a reverse electrodialysis energy release module.

[0023] The application further provides a use method of a second natural cold energy storage and conversion system, and the use method is characterized in that:

[0024] In cold weather, the dilute solution is frozen and concentrated by a freezing and concentrating module to obtain ice and concentrated solution, the ice is stored in an ice slurry storage tank, and the concentrated solution is stored in a concentrated solution storage tank; when power is needed, energy stored in the ice and the concentrated solution is converted into power output through energy release operation of a solution energy release module or through energy release operation of a reverse electrodialysis energy release module.

[0025] The application further provides a use method of a second natural cold energy storage and conversion system, and the use method is characterized in that:

[0026] The method for freezing and concentrating the dilute solution is any one of the following methods:

[0027] The first freezing and concentrating method is as follows:

[0028] Under the action of the fan, air flows in from the outside of the air filter, flows upwards through the spray tower, and then flows out after mixing;

[0029] The dilute solution in the dilute solution storage tank flows through a solution filter, a first solution pump and a solution passage of the heat exchanger, and then sprays and falls into the solution separator through a liquid distributor, and the dilute solution is preliminarily cooled to near freezing point in the heat exchanger and is further cooled and frozen into supercooled dilute solution in the spray tower;

[0030] The second freezing and concentrating method is as follows:

[0031] Under the action of the fan, air flows through the air passage of the heat exchanger and then flows out;

[0032] The dilute solution in the dilute solution storage tank flows through a solution filter, a first solution pump and a solution passage of the heat exchanger, and then sprays and falls into the solution separator through a liquid distributor, and the dilute solution is preliminarily cooled to near freezing point in the heat exchanger and is further cooled and frozen into supercooled dilute solution in the spray tower;

[0033] The third freeze concentration method is:

[0034] Under the action of the fan, air flows from the outside of the air filter into the spray tower and flows upward;

[0035] The dilute solution in the dilute solution storage tank is sprayed into the solution separator after passing through the solution filter, the first solution pump and the liquid distributor, and the dilute solution is cooled and frozen into supercooled dilute solution in the spray tower;

[0036] The method for separating ice and concentrated solution is:

[0037] The supercooled dilute solution is gathered into ice slurry at the upper part of the solution separator and is enriched into concentrated solution at the bottom; the concentrated solution is pumped into the concentrated solution storage tank by the concentrated solution pump; the ice slurry is separated into ice and dilute solution after being pumped into the ice slurry separator by the ice slurry pump; the dilute solution in the ice slurry separator is combined with the dilute solution in the dilute solution storage tank and then enters the first solution pump to continue the dilute solution freeze concentration process; and the ice is stored in the ice slurry storage tank.

[0038] As a further improvement of the natural cold energy storage and conversion utilization system:

[0039] The method for the solution energy release module to perform energy release operation is:

[0040] The concentrated solution in the concentrated solution storage tank is pressurized by the concentrated solution feed pump, filtered by the first concentrated solution filter, and then sent to the low-pressure side passage of the pressure exchanger; after being pressurized, the concentrated solution is pressurized by the concentrated solution pressurizing pump, filtered by the second concentrated solution filter, and then enters the concentrated side passage of the permeation membrane;

[0041] The liquid water in the ice slurry storage tank is pressurized by the fresh water pump and filtered by the fresh water filter, and then sent to the fresh side passage of the permeation membrane; the liquid water permeates through the permeation membrane into the concentrated side passage, mixes with the concentrated solution to become dilute solution, and the dilute solution flows out of the permeation membrane and is divided into two streams; one stream drives the hydraulic turbine generator to generate electricity and then enters the dilute solution storage tank for storage, and the other stream flows through the high-pressure side passage of the pressure exchanger and then enters the dilute solution storage tank for storage.

[0042] As a further improvement of the natural cold energy storage and conversion utilization system:

[0043] The method for the reverse osmosis energy storage and release module to perform reverse osmosis operation is any one of the following:

[0044] Reverse osmosis method one: the dilute solution in the dilute solution storage tank is sent into the low pressure side of the pressure exchanger after being filtered by the seventh switch valve, the concentrated solution feed pump pressurization and the first concentrated solution filter, absorbs the pressure of the high pressure side, and then is pressurized by the second concentrated solution pressurization pump and filtered by the second concentrated solution filter before entering the permeation membrane; the fresh water generated by reverse osmosis is stored in the ice slurry storage tank through the second switch valve, the fresh water filter, the check valve and the first switch valve; the concentrated solution generated by reverse osmosis is stored in the concentrated solution storage tank through the eleventh switch valve;

[0045] Reverse osmosis method two: the liquid water in the ice slurry storage tank is sent into the low pressure side of the pressure exchanger after being filtered by the third switch valve, the concentrated solution feed pump pressurization and the first concentrated solution filter, is pressurized, and then is pressurized by the second concentrated solution pressurization pump and filtered by the second concentrated solution filter before entering the concentrated side passage of the permeation membrane; the fresh water generated by reverse osmosis is stored in the ice slurry storage tank through the second switch valve, the fresh water filter, the check valve and the first switch valve; the concentrated solution generated by reverse osmosis is stored in the dilute solution storage tank through the eleventh switch valve.

[0046] As a further improvement of the use method of the natural cold energy storage and conversion system of the application:

[0047] The method for releasing energy by the reverse osmosis energy storage and release module is:

[0048] The concentrated solution in the concentrated solution storage tank is sent into the low pressure side of the pressure exchanger after being filtered by the sixth switch valve, the concentrated solution feed pump pressurization and the first concentrated solution filter, is pressurized, and then is pressurized by the first concentrated solution pressurization pump and filtered by the second concentrated solution filter before entering the concentrated side passage of the permeation membrane;

[0049] The fresh water in the ice slurry storage tank flows into the dilute side passage of the permeation membrane through the first switch valve, the fresh water pump, the fresh water filter and the second switch valve, enters the concentrated side passage to mix with the concentrated solution under the osmotic pressure, and is divided into two paths after flowing out, one of which enters the dilute solution storage tank after generating electricity by the hydraulic turbine generator driven by the fourteenth switch valve to recover energy, and the other of which enters the dilute solution storage tank through the eleventh switch valve, the high pressure side of the pressure exchanger and the thirteenth switch valve;

[0050] Meanwhile, the fresh water in the ice slurry storage tank is pumped into the cooling channel of the photovoltaic power generation panel by the cold water pump to cool the photovoltaic cell.

[0051] As a further improvement of the use method of the natural cold energy storage and conversion system of the application:

[0052] The method for releasing energy by the reverse osmosis energy storage and release module is:

[0053] The concentrated solution in the concentrated solution storage tank is pressurized by a concentrated solution feed pump, filtered by a first concentrated solution filter, and then distributed to each concentration chamber. The fresh water in the ice slurry storage tank is pressurized by a fresh water pump, filtered by a fresh water filter, and then distributed to each dilution chamber, so that an electric current passes through an external load and is output; the concentrated solution in the concentration chamber is reduced in concentration to become a dilute solution, and the fresh water in the dilution chamber is increased in concentration to become a dilute solution, and the two streams of dilute solutions are mixed and then enter the dilute solution storage tank for storage.

[0054] The beneficial effects of the present application mainly include:

[0055] The present application is designed to solve the problem of the current energy storage technology. The natural cold energy cross-season storage system based on solution can store, convert or transport natural cold energy or other forms of cold energy (such as liquefied natural gas that needs to be vaporized) in the form of aqueous solution of Na2SO4, MgCl2, CaCl2, MgSO4, KNO3, NaCl, or mixed solution of two or three of them, hydrate and ice. When needed, the osmotic pressure principle can be used to convert mechanical energy output through single-stage or multi-stage series pressure retarded osmosis (damping osmosis), or output electric energy through reverse electrodialysis, or a combination of pressure retarded osmosis and reverse electrodialysis to output electric energy. The stored cold energy can also be used to cool photovoltaic cells and improve their power generation efficiency, thereby providing a new renewable energy utilization system. BRIEF DESCRIPTION OF DRAWINGS

[0056] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0057] Figure 1 Figure 1 is a structural schematic diagram of a natural cold energy storage and conversion utilization system according to the present application;

[0058] Figure 2 Figure 2 is a structural schematic diagram of a natural cold energy storage and conversion utilization system according to the present application;

[0059] Figure 3 Figure 3 is a structural schematic diagram of a natural cold energy storage and conversion utilization system according to the present application;

[0060] Figure 4 Figure 4 is a structural schematic diagram of a natural cold energy storage and conversion utilization system according to the present application;

[0061] Figure 5 Figure 5 is a structural schematic diagram of a natural cold energy storage and conversion utilization system according to the present application;

[0062] Figure 6 Figure 6 is a structural schematic diagram of a natural cold energy storage and conversion utilization system according to the present application;

[0063] Figure 7Figure 7 is a connection diagram of the solution storage module and the reverse electrodialysis energy release module in the natural cold energy storage and conversion system scheme 7 of the present application;

[0064] Figure 8 Figure 8 is a diagram of two reverse electrodialysis energy release modules connected in series;

[0065] Figure 9 Figure 9 is an example diagram of an implementation of the dilute solution storage tank of the present application; Figure 9 Figure 10 is a diagram of the internal structure of the dilute solution storage tank, the internal flow direction of the dilute solution storage tank during energy release operation, and the A-A cross-sectional view of (a);

[0066] Figure 10 Figure 11 is a diagram of the use of a natural lake to implement the concentrated solution storage tank, the ice slurry storage tank, and the dilute solution storage tank. DETAILED DESCRIPTION

[0067] The present application will be further described below in conjunction with specific embodiments, but the scope of protection of the present application is not limited to this:

[0068] Example 1, a natural cold energy storage and conversion system scheme 1, as shown in Cooling final temperature (°C) includes a freezing and concentration module, a solution storage module, and a solution energy release module.

[0069] During cold weather, the water solution of salt substances such as Na2SO4, KNO3, MgSO4, NaCl, MgCl2, CaCl2, or a mixed solution of two or three kinds of salt can be frozen by the freezing and concentration module, a portion of the water in the solution is frozen into ice, and the remaining solution is concentrated, thereby realizing the concentration of the solution. The ice and the solution are separated and stored separately, thereby realizing the conversion and storage of natural cold energy. When electricity is needed, the energy stored in the ice and the concentrated solution is converted into electric power output by the solution energy release module, thereby realizing the cyclic utilization of natural cold energy storage and conversion.

[0070] The freezing and concentration module includes, from bottom to top, a solution separator 17, an air filter 18, a spray tower 19, a heat exchanger 20, and a fan 21.

[0071] The heat exchanger 20 is a finned tube (circular tube or elliptical tube) or plate-fin type or micro-channel type heat exchanger. The solution passage (for example, the finned tube or the plate-fin) of the heat exchanger 20 is used to pass the dilute solution, and the ambient air flows through the air passage (the outer surface of the solution passage) of the heat exchanger 20 to exchange heat with the dilute solution in the solution passage, thereby cooling the dilute solution. A spray type liquid distributor 22 is provided at the top of the spray tower 19, and the solution passage outlet of the heat exchanger 20 is connected to the spray type liquid distributor 22 through a pipeline.

[0072] The upper and lower edges of the air filter 18 are respectively connected in an air-tight manner with the bottom of the tower body of the spray tower 19 and the top of the solution separator 17, and the upper and lower edges of the heat exchanger 20 are respectively connected in an air-tight manner with the upper part of the tower body of the spray tower 19 and the lower part of the fan 21.

[0073] When the fan 21 is working, the ambient air is sucked from the outside of the air filter 18, and after the dust in the air is filtered, the clean air enters the bottom of the spray tower 19 and the upper space of the solution separator 17 and flows upward, exchanges heat with the falling dilute solution in the spray tower 19, and the dilute solution is cooled and frozen; at the same time, another part of the ambient air flows through the air passage of the heat exchanger 20 under the action of the fan 21, exchanges heat with the dilute solution in the solution passage of the heat exchanger 20, and after the dilute solution is cooled, the part of the ambient air flowing through the heat exchanger 20 is mixed with the ambient air entering from the filter in the lower part, and is discharged outward under the suction of the fan 21.

[0074] The solution separator 17 is used to separate the solid ice and the concentrated solution (liquid solution and hydrate) generated after the solution is frozen. The separated ice slurry is gathered in the upper part of the inner cavity of the solution separator 17, and the separated liquid and hydrate are located in the lower part of the inner cavity of the solution separator 17. An ice slurry outlet is opened in the upper part of the solution separator 17, and a solution outlet is opened in the bottom. The solution outlet is connected to the solution storage module through the concentrated solution pump 16, and the ice slurry outlet is connected to the inlet of the ice slurry separator 14 through the ice slurry pump 15. The ice slurry outlet of the ice slurry separator 14 is connected to the solution storage module through a pipeline, and the solution outlet of the ice slurry separator 14 is connected to the inlet of the solution passage of the heat exchanger 20 through the second solution pump 141, so as to realize the freezing concentration and separation of the dilute solution.

[0075] The solution storage module includes a concentrated solution storage tank 4, an ice slurry storage tank 2 and a dilute solution storage tank 1. The solution release module includes a concentrated solution feeding pump 5, a first concentrated solution filter 6, a pressure exchanger 7, a first concentrated solution booster pump 8, a second concentrated solution filter 9, a permeable membrane 10, a hydraulic turbine generator 11, a fresh water pump 201 and a fresh water filter 101.

[0076] The dilute solution storage tank 1 is used to store the dilute solution input from the solution release module, and includes a dilute solution inlet at the top and a dilute solution outlet at the bottom. The dilute solution outlet is connected to the inlet of the solution filter 13 through a pipeline, and the outlet of the solution filter 13 is connected to the inlet of the solution passage of the heat exchanger 20 through the first solution pump 12 (i.e. the outlet of the first solution pump 12 and the outlet of the second solution pump 141 are combined into one through a pipeline and then input into the solution passage of the heat exchanger 20), so as to input the dilute solution needing to be frozen and concentrated into the freezing and concentration module.

[0077] The concentrated solution storage tank 4 stores the concentrated solution input from the cryogenic concentration module, including a concentrated solution inlet at the top and a concentrated solution outlet at the bottom. The concentrated solution inlet is connected to the concentrated solution pump 16 via a pipeline. The concentrated solution outlet is connected to the concentrated solution feed pump 5, the first concentrated solution filter 6, the low-pressure side passage of the pressure exchanger 7, the concentrated solution booster pump 8, the second concentrated solution filter 9, and the concentrated side passage of the permeate membrane 10 via a pipeline, before splitting into two paths. One path connects to the dilute solution inlet of the dilute solution storage tank 1 via the hydraulic turbine generator 11, and the other path connects to the dilute solution inlet of the dilute solution storage tank 1 via the high-pressure side passage of the pressure exchanger 7. The hydraulic turbine generator 11 uses the high-pressure solution to drive power generation, realizing energy conversion.

[0078] The inlet of the ice slurry storage tank 2 is connected to the ice slurry outlet of the ice slurry separator 14 via a pipeline, and the outlet of the ice slurry storage tank 2 is connected to the fresh water side passage of the permeate membrane 10 via a pipeline after passing through the fresh water pump 201 and the fresh water filter 101.

[0079] The usage method of Scheme 1 for a natural cold energy storage and conversion utilization system is as follows:

[0080] 1. Freezing concentration and separation of solutions

[0081] 1.1 The dilute solution in the dilute solution storage tank 1 is filtered by the solution filter 13, and then enters the liquid distributor 22 for spraying through the solution passage of the heat exchanger 20 by the first solution pump 12. It falls in the spray tower 19 and at the same time comes into contact with the outside air filtered by the filter 18 to exchange heat and mass before falling into the solution separator 17.

[0082] Ambient air flows in from the outside of air filter 18 and heat exchanger 20 under the action of fan 21. The air flowing in from air filter 18 flows from bottom to top through spray tower 19. During the flow, it exchanges heat and mass with the falling solution in spray tower 19. After flowing out of spray tower 19, it mixes with the outside air passing through heat exchanger 20 and is discharged to the outside.

[0083] 1.2 Inside the heat exchanger 20, air passes over the heat exchange surface of the air passage and exchanges heat with the dilute solution in the solution passage. The dilute solution is initially cooled by the air to near the freezing point before entering the liquid distributor 22.

[0084] 1.3 Inside the spray tower 19, the dilute solution nearing the freezing point, sprayed down from the liquid distributor 22, comes into contact with the air flowing upwards and is further cooled and frozen. The dilute solution that reaches the freezing point falls into the solution separator 17.

[0085] 1.4, In the solution separator 17, the generated ice is lighter in density and gathered in the upper part of the solution separator 17 as ice slurry, which is pumped by the ice slurry pump 15 into the ice slurry separator 14 to separate the ice and the dilute solution, the dilute solution is returned into the solution passage of the heat exchanger 20 to continue the freezing and concentration process under the action of the second solution pump 141, and the ice is stored in the ice slurry storage tank 2 as fresh water containing a small amount of salt.

[0086] In the solution separator 17, due to the precipitation of ice, the concentration and density of the remaining solution increase to become a concentrated solution, and hydrates are generated, the concentrated solution and hydrates with higher density are enriched at the bottom of the solution separator 17, and are sent into the concentrated solution storage tank 4 by the concentrated solution pump 16 for storage.

[0087] 2, Energy release operation

[0088] The concentrated solution in the concentrated solution storage tank 4 is pressurized by the concentrated solution feed pump 5, filtered by the first concentrated solution filter 6, and then sent to the low-pressure side passage of the pressure exchanger 7, and then pressurized by the concentrated solution booster pump 8, filtered by the second concentrated solution filter 9, and then enters the concentrated side passage of the permeation membrane 10;

[0089] The liquid water in the ice slurry storage tank 2 is pressurized by the fresh water pump 201 and then filtered by the fresh water filter 101, and then sent to the dilute side passage of the permeation membrane 10, and under the action of the osmotic pressure, the liquid water permeates through the permeation membrane 10 into the concentrated side passage with higher pressure; in the concentrated side passage, the original concentrated solution with higher pressure is mixed with the liquid water to become a dilute solution, and the mixed dilute solution flows out from the concentrated side passage of the permeation membrane 10 and is divided into two streams, one enters the hydraulic turbine generator 11 to drive the hydraulic turbine generator 11 to generate electricity and then enters the dilute solution storage tank 1; the other enters the high-pressure side passage of the pressure exchanger 7 to pressurize the concentrated solution in the low-pressure side passage, and then flows out from the pressure exchanger 7 and enters the dilute solution storage tank 1.

[0090] In this embodiment, the natural cold energy is used to freeze and concentrate the dilute solution, the natural cold energy is converted into solution chemical energy for storage, and then the solution chemical energy is converted into solution potential energy through pressure damping permeation, and then the solution potential energy is converted into mechanical energy through the hydraulic turbine to drive the generator to generate electricity, thereby further converting into electrical energy. It is a new technology for converting, storing and utilizing natural energy-low temperature air cold energy.

[0091] Embodiment 2, a natural cold energy storage and conversion utilization system scheme 2, as shown in Precipitated ice (kg)As shown, including a freeze concentration module, a solution storage module and a solution release module, wherein the solution storage module and the solution release module are the same as example 1, and the freeze concentration module is slightly different from scheme 1, the specific difference is: the air filter 18 between the solution separator 17 and the spray tower 19 in example 1 is cancelled, the bottom of the tower body of the spray tower 19 is directly connected with the top of the solution separator 17, and the inner cavities of the spray tower 19 and the solution separator 17 are through from top to bottom. In cold weather, the dilute solution is frozen and concentrated by the freeze concentration module, and ice and concentrated solution are separated and obtained, the ice is stored in the ice slurry storage tank 2, and the concentrated solution is stored in the concentrated solution storage tank 4; when power is needed, or through the solution release module for release operation, the energy stored in the ice and the concentrated solution is converted into electric power output.

[0092] The use method of a natural cold energy storage and conversion utilization system scheme 2 is:

[0093] 1. Freeze concentration of solution

[0094] 1.1, the flow path of the dilute solution is the same as step 1.1 of example 1: the dilute solution in the dilute solution storage tank 1 passes through the solution filter 13, the first solution pump 12, the solution passage of the heat exchanger 20, and then enters the liquid distributor 22 for spraying, and falls to the solution separator 17 in the spray tower 19;

[0095] Compared with step 1.1 of example 1, the air filter 18 is cancelled, and in this embodiment, the environmental air flows through the air passage of the heat exchanger 20 under the action of the fan 21, and is discharged into the external environment by the fan 21 after heat exchange with the dilute solution in the solution passage of the heat exchanger 20.

[0096] 1.2, in the heat exchanger 20, the dilute solution in the solution passage of the heat exchanger 20 is cooled and in a supercooled state, and enters the liquid distributor 22;

[0097] Compared with step 1.1 of example 1, the freeze of the dilute solution in this embodiment is only realized by the heat exchanger 20, which can reduce the evaporation loss of water and the carrying loss of the solution in the process of direct contact between the solution and the air, and the dilute solution is supercooled by the cold air in the heat exchanger 20, that is, cooled below the freezing point while keeping liquid state, and then enters the liquid distributor 22.

[0098] 1.3, in the spray tower 19, a part of the dilute solution will be supercooled and frozen in the process of falling to the solution separator 17 under spraying;

[0099] 1.4, the same as step 1.4 of example 1.

[0100] 2. Release operation, the same as step 2 of example 1.

[0101] Example 3, a natural cold energy storage and conversion utilization system scheme 3, as shown inMass concentration of solution (%) As shown, it comprises a freeze concentration module, a solution storage module and a solution energy release module, wherein the solution storage module and the solution energy release module are the same as those in Scheme 1, and the freeze concentration energy storage module is slightly different from that in Scheme 1, specifically as follows: the heat exchanger 20 is cancelled, the fan 21 is arranged at the top of the spray tower 19 to achieve negative pressure forced ventilation at the top of the spray tower 19, and the outlets of the first solution pump 12 and the second solution pump 141 are directly connected with the liquid distributor 22 through pipelines for directly introducing the dilute solution into the spray tower 19. The freeze concentration of the dilute solution is only completed by the direct contact between the solution and the cold air in the spray tower 19. In cold weather, the dilute solution is freeze concentrated by the freeze concentration module to separate ice and concentrated solution, the ice is stored in the ice slurry storage tank 2, and the concentrated solution is stored in the concentrated solution storage tank 4; when power is needed, or the energy stored in the ice and the concentrated solution is converted into electric power output by the solution energy release module.

[0102] The use method of the natural cold energy storage and conversion utilization system scheme 3 is as follows:

[0103] 1. Freeze concentration of the solution

[0104] 1.1, The dilute solution in the dilute solution storage tank 1 is filtered by the filter 13 and then sent into the liquid distributor 22 by the first solution pump 12 to be sprayed and fall in the spray tower 19, and in the falling process, the solution is directly contacted with the ambient air flowing upwards after being filtered by the air filter 18 to exchange heat and mass, and the solution is cooled and then falls into the solution separator 17.

[0105] The ambient air flows into the spray tower 19 from below to above under the action of the fan 21 and is discharged outward from the spray tower 19.

[0106] 1.2, In the spray tower 19, the sprayed and falling dilute solution is cooled and frozen by contacting with the air flowing from below to above.

[0107] 1.3, The process in the solution separator 17 is consistent with step 1.4 of Example 1.

[0108] 2. Energy release operation, which is the same as step 2 of Example 1.

[0109] Example 4, a natural cold energy storage and conversion utilization system scheme 4, as shown in Molar concentration (m / L) It comprises a freeze concentration module, a solution storage module and a reverse osmosis energy storage and release module, wherein the freeze concentration module is consistent with the freeze concentration module in Example 1, and additionally, a reverse osmosis concentration component is added to concentrate the dilute solution and the ice slurry melt water containing salt produced by freeze concentration through reverse osmosis operation.

[0110] The reverse osmosis energy storage and release module comprises a circulating passage in which the osmosis membrane 10 and the hydraulic turbine generator 11 are located and a circulating passage in which the cooling passage of the photovoltaic power generation panel 142 is located, specifically: the dilute solution outlet of the dilute solution storage tank 1 is sequentially connected to the seventh switch valve 402, the concentrated solution feed pump 5, the first concentrated solution filter 6, the low-pressure side passage of the pressure exchanger 7, and then divided into two parallel paths, one path is connected to the fifteenth switch valve 601 and the first concentrated solution booster pump 8, and the other path is connected to the sixteenth switch valve 602 and the second concentrated solution booster pump 81, then the outlets of the first concentrated solution booster pump 8 and the second concentrated solution booster pump 81 are combined into one path, and then connected to the concentrated side passage inlet of the osmosis membrane 10 through the second concentrated solution filter 9. The second concentrated solution booster pump 81 and the first concentrated solution booster pump 8 are arranged in parallel to provide different pressure boosting effects, wherein the first concentrated solution booster pump 8 is used for the energy release process, and the second concentrated solution booster pump 81 is used for the concentration energy storage process of the reverse osmosis operation.

[0111] The outlet of the concentrated side passage of the osmosis membrane 10 is divided into two paths, one path is connected to the fourteenth switch valve 606, the hydraulic turbine generator 11, and then connected to the inlet of the dilute solution storage tank 1, and the other path is connected to the eleventh switch valve 603, the high-pressure side passage of the pressure exchanger 7, and then divided into two paths, one path is connected to the thirteenth switch valve 605 and then connected to the inlet of the dilute solution storage tank 1, and the other path is connected to the eighth switch valve 403 and then connected to the inlet of the concentrated solution storage tank 4.

[0112] The dilute side passage of the osmosis membrane 10 is connected to the second switch valve 204, the fresh water filter 101, then connected to the parallel fresh water pump 201 and the check valve 205 (the flow direction of the passage where the check valve 205 is located is from the osmosis membrane 10 to the ice slurry storage tank 2, and the flow direction of the passage where the fresh water pump 201 is located is from the ice slurry storage tank 2 to the osmosis membrane 10), and then connected to the first switch valve 202 and the inlet of the ice slurry storage tank 2.

[0113] The outlet of the concentrated solution storage tank 4 is connected to the sixth switch valve 401, and the outlet of the ice slurry storage tank 2 is connected to the third switch valve 203, both of which are connected to the inlet of the concentrated solution feed pump 5.

[0114] The outlet of the ice slurry storage tank 2 is connected to the cold water pump 3, the cooling passage of the photovoltaic power generation panel 142, the cold water filter 31, and then connected to the inlet of the ice slurry storage tank 2.

[0115] The remaining devices and connection modes are the same as those in Example 1. In cold weather, the dilute solution is frozen and concentrated by the freezing and concentrating module to separate ice and concentrated solution, the ice is stored in the ice slurry storage tank 2, and the concentrated solution is stored in the concentrated solution storage tank 4; at night or when there is low-price electricity on the power grid, the reverse osmosis operation is performed by the reverse osmosis energy storage and release module to concentrate the dilute solution for energy storage; when electricity is needed, the energy stored in the ice and the concentrated solution is converted into electric power output by performing the energy release operation by the reverse osmosis energy storage and release module.

[0116] The use method of the natural cold energy storage and conversion utilization system scheme 4 is as follows:

[0117] In cold weather, ice and concentrated solution are obtained by freezing and concentrating the dilute solution in the freezing and concentrating module, and are stored in the ice slurry storage tank 2 and the concentrated solution storage tank 4 respectively, so as to realize the conversion and storage of natural cold energy. When there is surplus low-price electric energy at night or on the power grid, the reverse osmosis energy storage and release module can be used to store energy by concentrating the dilute solution through the principle of reverse osmosis. When electric power is needed, the energy stored in the ice and concentrated solution can be converted into electric power output through the reverse osmosis energy storage and release module, so as to realize the cyclic utilization of natural cold energy storage and conversion.

[0118] 1. Freezing and concentrating of the solution

[0119] During the operation of the freezing and concentrating process of the solution, the sixth switch valve 401, the seventh switch valve 402, the eighth switch valve 403, the first switch valve 202 and the third switch valve 203 are closed.

[0120] The step 1 of the embodiment 1 is consistent with that of the embodiment 1: the dilute solution in the dilute solution storage tank 1 is preliminarily cooled to near the freezing point by the air through the heat exchanger 20, and then is further cooled to reach the freezing point in the process of falling and spraying in the spray tower 19, and then the separated ice enters the ice slurry storage tank 2 for storage, and the concentrated solution is sent to the concentrated solution storage tank 4 for storage by the concentrated solution pump 16.

[0121] 2. Reverse osmosis operation

[0122] 2.1. Reverse osmosis mode one

[0123] 2.1.1. Concentration and energy storage operation

[0124] (1) The second switch valve 204, the first switch valve 202, the seventh switch valve 402, the sixteenth switch valve 602, the eleventh switch valve 603 and the eighth switch valve 403 are opened.

[0125] The third switch valve 203, the sixth switch valve 401, the fifteenth switch valve 601, the thirteenth switch valve 605 and the fourteenth switch valve 606 are closed.

[0126] (2) The dilute solution in the dilute solution storage tank 1 is sent to the low pressure side of the pressure exchanger 7 after being pressurized by the seventh switch valve 402, the concentrated solution feed pump 5, the first concentrated solution filter 6, and the pressure is increased after absorbing the pressure of the high pressure side, and then is sent to the concentrated side passage of the permeation membrane 10 after being pressurized by the second concentrated solution pressurizing pump 81 and filtered by the second concentrated solution filter 9; under the action of the permeation membrane and the higher pressure, the ions in the dilute solution are intercepted by the permeation membrane 10 to become concentrated solution, and the water molecules pass through the permeation membrane 10 to enter the dilute side; the dilute water generated by reverse osmosis is stored in the ice slurry storage tank 2 after passing through the second switch valve 204, the dilute water filter 101, the one-way valve 205 (the dilute water pump 201 is not working), and the first switch valve 202; the concentrated solution generated by reverse osmosis is sent to the high pressure side of the pressure exchanger 7 through the eleventh switch valve 603, the pressure of the dilute solution in the low pressure side is reduced after being pressurized, and then is sent to the concentrated solution storage tank 4 through the eighth switch valve 403.

[0127] 2.1.2, energy release operation

[0128] (1) The third switch valve 203, the eighth switch valve 403, the seventh switch valve 402, and the sixteenth switch valve 602 are closed.

[0129] The sixth switch valve 401, the fifteenth switch valve 601, the first switch valve 202, the second switch valve 204, the fourteenth switch valve 606, the eleventh switch valve 603, and the thirteenth switch valve 605 are opened.

[0130] (2) The concentrated solution stored in the concentrated solution storage tank 4 is sent to the low pressure side of the pressure exchanger 7 after being pressurized by the sixth switch valve 401, the concentrated solution feed pump 5, and the first concentrated solution filter 6, and the pressure is increased after being pressurized by the high pressure side, and then is sent to the concentrated side passage of the permeation membrane 10 after being pressurized by the first concentrated solution pressurizing pump 8 and filtered by the second concentrated solution filter 9.

[0131] The dilute water in the ice slurry storage tank 2 is sent to the dilute side passage of the permeation membrane 10 after passing through the first switch valve 202, the dilute water pump 201 (the one-way valve 205 is in the closed state), the dilute water filter 101, and the second switch valve 204; under the action of the osmotic pressure, the dilute water enters the concentrated side passage and mixes with the concentrated solution in the concentrated side passage with higher pressure, and then flows out from the concentrated side passage of the permeation membrane 10 and is divided into two paths; one path is sent to the hydraulic turbine generator 11 through the fourteenth switch valve 606 to drive the hydraulic turbine generator 11 to generate electricity and recover energy, and then is stored in the dilute solution storage tank 1; the other path is sent to the high pressure side of the pressure exchanger 7 through the eleventh switch valve 603 to pressurize the concentrated solution in the low pressure side, and then is sent to the dilute solution storage tank 1 through the thirteenth switch valve 605.

[0132] The low-temperature cold water after the ice slurry stored in the ice slurry storage tank 2 is melted can be sent to the cooling channel of the photovoltaic power generation panel 142 by the cold water pump 3 to cool the photovoltaic cell and improve the power generation efficiency. After the cold water flows through the cooling channel of the photovoltaic power generation panel 142, the temperature is increased, and after being filtered by the cold water filter 31, the cold water is stored in the ice slurry storage tank 2.

[0133] 2.2, reverse osmosis mode two

[0134] 2.2.1, concentrated energy storage operation

[0135] When the salt content in the ice slurry generated in the freezing and concentration process of the solution in step 1 is too high, the concentrated energy storage operation in reverse osmosis mode two is performed.

[0136] The third switch valve 203, the second switch valve 204, the sixteenth switch valve 602, the eleventh switch valve 603, and the thirteenth switch valve 605 are opened.

[0137] The sixth switch valve 401, the seventh switch valve 402, the eighth switch valve 403, the fifteenth switch valve 601, and the fourteenth switch valve 606 are closed.

[0138] The liquid water containing salt in the ice slurry storage tank 2 is sent to the low-pressure side of the pressure exchanger 7 through the third switch valve 203, and then pressurized by the concentrated solution feed pump 5, filtered by the first concentrated solution filter 6, and then pressurized by the second concentrated solution pressurizing pump 81, filtered by the second concentrated solution filter 9, and then enters the concentrated side passage of the osmotic membrane 10. Under the action of pressure and osmotic membrane, the ions in the liquid water containing salt are retained by the osmotic membrane to become concentrated solution, and the water molecules penetrate the osmotic membrane to produce fresh water. The produced fresh water is stored in the ice slurry storage tank 2 through the second switch valve 204, the fresh water filter 101, the one-way valve 205, and the first switch valve 202. The produced concentrated solution enters the high-pressure side of the pressure exchanger 7 through the eleventh switch valve 603, and the pressure of the low-pressure side of the liquid water containing salt is reduced after being pressurized by the concentrated solution, and then enters the dilute solution storage tank 1 through the thirteenth switch valve 605.

[0139] 2.2.2, energy release operation, same as step 2.1.2.

[0140] Embodiment 5, a natural cold energy storage and conversion utilization system scheme 5, as shown in Osmotic pressure (atm)As shown, including freeze concentration module, solution storage module and reverse osmosis energy storage and release module, wherein the freeze concentration module is consistent with the freeze concentration module of embodiment 2, the solution storage module and the reverse osmosis energy storage and release module are consistent with the solution storage module and the reverse osmosis energy storage and release module of embodiment 4. In cold weather, the dilute solution is frozen and concentrated by the freeze concentration module, and ice and concentrated solution are obtained after separation, the ice is stored in the ice slurry storage tank 2, and the concentrated solution is stored in the concentrated solution storage tank 4, and when there is low-priced electricity at night or on the power grid, the dilute solution is concentrated by reverse osmosis operation through the reverse osmosis energy storage and release module; when power is needed, the energy stored in the ice and the concentrated solution is converted into electric power output by the reverse osmosis energy storage and release module.

[0141] Embodiment 6, a natural cold energy storage and conversion utilization system scheme 6, as shown, Equivalent water head (m) As shown, including freeze concentration module, solution storage module and reverse osmosis energy storage and release module, wherein the freeze concentration module is consistent with the freeze concentration module of embodiment 3, the solution storage module and the reverse osmosis energy storage and release module are consistent with the solution storage module and the reverse osmosis energy storage and release module of embodiment 4. In cold weather, the dilute solution is frozen and concentrated by the freeze concentration module, and ice and concentrated solution are obtained after separation, the ice is stored in the ice slurry storage tank 2, and the concentrated solution is stored in the concentrated solution storage tank 4, and when there is low-priced electricity at night or on the power grid, the dilute solution is concentrated by reverse osmosis operation through the reverse osmosis energy storage and release module; when power is needed, the energy stored in the ice and the concentrated solution is converted into electric power output by the reverse osmosis energy storage and release module.

[0142] Embodiment 7, a natural cold energy storage and conversion utilization system scheme 7

[0143] The energy release process is carried out by reverse electrodialysis. Including freeze concentration module, solution storage module and reverse electrodialysis energy release module, the freeze concentration module and the solution storage module adopt any one of embodiments 1-3, and after freeze concentration according to the schemes of the foregoing embodiments 1-3, the concentrated solution and the fresh water are generated, the conversion and storage of natural cold energy and electric energy are completed, and the energy release process is carried out by reverse electrodialysis. The connection of the reverse electrodialysis energy release module and the solution storage module is as shown in Corresponding potential energy (kWh) simplified diagram, ​The freezing and concentration module is omitted. In the reverse electrodialysis module, cation exchange membranes and anion exchange membranes are arranged in sequence and are spaced apart. The leftmost side is the anode chamber 52, the rightmost side is the cathode chamber 53, and the middle is a plurality of groups of concentrated chambers 54 and dilute chambers 56 (the left side of the concentrated chamber 54 is a cation exchange membrane, only cations can pass through, and the right side is an anion exchange membrane, only anions can pass through, and the right side of the dilute chamber 56 is a cation exchange membrane, and the left side is an anion exchange membrane). The concentrated solution outlet of the concentrated solution storage tank 4 is connected to the concentrated solution feed pump 5, the first concentrated solution filter 6, and the concentrated chamber 54 inlet, and the outlet of the ice slurry storage tank 2 is connected to the dilute water pump 201, the dilute water filter 101, and the dilute chamber 56 inlet. The outlets of the concentrated chamber 54 and the dilute chamber 56 are connected to the inlet of the dilute solution storage tank 1.

[0144] An anode electrode 522 and a cathode electrode 533 are respectively arranged in the anode chamber 52 and the cathode chamber 53, and a DC power supply with an external load is used as a load.

[0145] The concentrated solution generated by the freezing and concentration module and stored in the concentrated solution storage tank 4 is filtered by the concentrated solution feed pump 5 and the first concentrated solution filter 6 and then distributed to each concentrated chamber 54. The dilute water generated by the freezing and concentration module and stored in the ice slurry storage tank 2 is filtered by the dilute water pump 201 and the dilute water filter 101 and then distributed to each dilute chamber 56. The anions and cations in the concentrated chamber 54 diffuse to the dilute chamber 56 through the ion exchange membranes on both sides, forming an electric current in the loop and outputting through the external load. Due to the continuous penetration and diffusion of anions and cations into the dilute chambers 56 on both sides during the flow process, the concentrated solution in the concentrated chamber 56 flows out and becomes dilute solution due to the decrease in concentration. Due to the continuous penetration of anions and cations from the concentrated chambers 54 on both sides, the dilute water in the dilute chamber 54 flows out and becomes dilute solution due to the increase in concentration. The two streams of dilute solution are mixed and then enter the dilute solution storage tank 1.

[0146] ​ The principle of the operation of two reverse electrodialysis modules in series is given: the dilute solution flowing out of one reverse electrodialysis stack enters the concentrated chamber of the next reverse electrodialysis stack to fully utilize the concentration difference of the solution.

[0147] At night or when there is excess low-price electricity on the power grid, the principle of electrodialysis can be used to concentrate dilute solution for energy storage operation.

[0148] ​ A scheme for improving the volume utilization rate of the dilute solution storage tank 1 is given. As shown in FIG. 6, the concentrated solution storage tank 4 is connected to the concentrated solution feed pump 5, the first concentrated solution filter 6, and the concentrated chamber 54 inlet, and the ice slurry storage tank 2 is connected to the dilute water pump 201, the dilute water filter 101, and the dilute chamber 56 inlet. The outlets of the concentrated chamber 54 and the dilute chamber 56 are connected to the inlet of the dilute solution storage tank 1. ​(a) As shown, the dilute solution storage tank 1 is divided into several small chambers by the alternate arrangement of upper vertical partitions 23 and lower vertical partitions 24. The upper vertical partitions 23 and lower vertical partitions 24 are respectively left with gaps from the bottom and top of the storage tank. Liquid can flow from top to bottom or from bottom to top and transfer between adjacent chambers through the liquid passages between the upper vertical partitions 23 and lower vertical partitions 24. The bottom of the upper vertical partitions 23 and the top of the lower vertical partitions 24 are provided with flow-distributing plates 22 to evenly distribute the liquid flowing into adjacent chambers on the cross section of the small chambers. The flow-distributing plate 22 is a porous plate with appropriate thickness. A flow-distributing plate structure with hexagonal cross section is given in 9(c). Such structure is conducive to the layered storage and utilization of liquids with different concentrations or temperatures.

[0149] During the freezing concentration operation, ​ (a) As shown, the dilute solution in the dilute solution storage tank 1 is drawn out from the right bottom 26 to the freezing concentration module, solution energy release module or reverse electrodialysis energy release module. The fresh water obtained by reverse osmosis (or electrodialysis) or freezing concentration is introduced from the left upper part 25 of the dilute solution storage tank 1 until the dilute solution storage tank 1 is filled with fresh water. During the energy release operation, ​ (b) As shown, the fresh water is drawn out from the left upper part of the dilute solution storage tank 1 and the dilute solution is introduced from the right lower part of the dilute solution storage tank 1 until the dilute solution storage tank 1 is filled with dilute solution.

[0150] ​ A scheme for storing solution in a natural lake is given. As shown, the lake is divided into two isolated parts by a partition wall 3 made of steel piles and concrete or other materials. The middle container is used to store solution. The density difference between the concentrated solution and dilute solution is utilized. The upper part of the middle container for storing dilute solution is equivalent to the dilute solution storage tank 1 and the bottom of the middle container for storing concentrated solution is equivalent to the concentrated solution storage tank 4. The space outside the partition wall 3 is used to store fresh water (ice) which is equivalent to the ice slurry storage tank 2. During the energy release operation, the concentrated solution is drawn out from the bottom of the middle container (concentrated solution storage tank 4) and the fresh water is drawn out from the fresh water area (ice slurry storage tank 2) to enter the membrane group. The dilute solution after energy release is returned to the upper part of the middle container (dilute solution storage tank 1). During the energy storage operation, the dilute solution is drawn out from the upper part of the middle container (dilute solution storage tank 1) to enter the concentration module. The concentrated solution is returned to the bottom of the middle container (concentrated solution storage tank 4) and the fresh water enters the fresh water area (ice slurry storage tank 2).

[0151] Experiment:

[0152] The feasibility of the scheme is demonstrated by taking calcium chloride solution as an example. A ton of calcium chloride solution with a mass concentration of 1.5% is cooled to below freezing point at different temperatures, and different amounts of ice are separated out. The mass concentration and molar concentration of the remaining solution after separation of the ice are different. According to the solubility of calcium chloride in water, the mass of ice that can be separated out and the concentration of the remaining solution when the initial concentration solution is cooled to different temperatures can be calculated. The ice and the solution are stored separately, which realizes the conversion and storage of natural cold energy. In summer, the energy stored in the ice in the solution can be converted into electric power output through pressure-damped osmosis, reverse electrodialysis or their combination. The cold energy stored in the ice and the solution is not taken into account, and only the energy that can be converted in the process of permeating the membrane by the fresh water produced by the melting of the solution and the ice is calculated. According to the thermodynamics of the solution, the osmotic pressure of the solution is calculated as follows:

[0153]

[0154] In the formula, i is the number of dissociable ions, and for calcium chloride, i is 3;

[0155] C is the molar concentration of the solution, mol / m 3 ;

[0156] R is the ideal gas constant, J / kg·K;

[0157] T is the thermodynamic temperature, K.

[0158] When the initial solution is cooled to different temperatures, the corresponding osmotic pressure of the remaining solution is shown in Table 1. As can be seen from Table 1, a very high osmotic pressure can be obtained by freezing and concentrating the solution. The ice and the solution after melting are subjected to pressure-damped osmosis (PRO) at room temperature (300K), and the conversion efficiency is 64%. The operating pressure is 1 / 2 of the osmotic pressure. A ton of calcium chloride solution with a mass concentration of 1.5% can theoretically convert and output the energy as shown in Table 1 after storing energy by freezing and concentrating using natural cold energy.

[0159] Table 1

[0160] ​ ​ ​ ​ ​ ​ ​ -5 834.29 9.05 0.879 64.9 649.1 0.5 -10 909.58 16.58 1.722 127.2 1271.7 1.0 -15 934.73 22.98 2.506 185.1 1850.6 1.5 -20 947.28 28.45 3.248 239.9 2398.6 2.0

[0161] According to the calculation results in the table, 1 ton of calcium chloride solution with a mass concentration of 1.5% can output 1.5 kWh of energy when cooled from 15 degrees to minus 15 degrees, which is equivalent to the energy output of a 540-meter-high dam. Considering that the winter in cold regions is long and the low-temperature weather is long, the scheme proposed by the present application can obtain considerable energy, which belongs to a new type of energy storage and renewable energy utilization technology.

[0162] Finally, it should be noted that the above enumeration is only several specific embodiments of the present application. Obviously, the present application is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or inferred by those of ordinary skill in the art from the disclosure of the present application should be considered within the scope of the present application.

Claims

1. A natural cold energy storage and conversion system, characterized in that: The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10).

2. A natural cold energy storage and conversion utilization system, characterized in that: The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). 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The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release module comprises a hydraulic turbine generator (11) and a permeation membrane (10). The solution storage module is connected with a solution energy release module, and the solution energy release The solution storage module comprises a dilute solution storage tank (1), an ice slurry storage tank (2) and a concentrated solution storage tank (4); the dilute solution outlet of the dilute solution storage tank (1) is connected to the ice slurry outlet of the solution separator (17) through a pipeline after a solution filter (13), a first solution pump (12) and an ice slurry pump (15), an ice slurry separator (14) and a second solution pump (141), and is connected to a spray liquid distributor (22) through a pipeline; the ice slurry outlet of the ice slurry separator (14) is connected to the inlet of the ice slurry storage tank (2); the concentrated solution inlet of the concentrated solution storage tank (4) is connected to the solution outlet of the solution separator (17) through a concentrated solution pump (16); The reverse osmosis energy storage and release module comprises a photovoltaic power generation panel (142), a hydraulic turbine generator (11) and an osmosis membrane (10); the dilute solution outlet of the dilute solution storage tank (1) is divided into two parallel pipelines after passing through a seventh switch valve (402), a concentrated solution feed pump (5), a first concentrated solution filter (6) and a low-pressure side passage of a pressure exchanger (7); one pipeline passes through a fifteenth switch valve (601) and a first concentrated solution booster pump (8), and the other pipeline passes through a sixteenth switch valve (602) and a second concentrated solution booster pump (81); then, the two pipelines are combined into one pipeline, which is connected to the concentrated side passage inlet of the osmosis membrane (10) after passing through a second concentrated solution filter (9); the outlet of the concentrated side passage of the osmosis membrane (10) is divided into two pipelines; one pipeline is connected to the inlet of the dilute solution storage tank (1) after passing through a fourteenth switch valve (606) and the hydraulic turbine generator (11); the other pipeline is divided into two pipelines after passing through an eleventh switch valve (603) and a high-pressure side passage of the pressure exchanger (7); one pipeline is connected to the inlet of the dilute solution storage tank (1) after passing through a thirteenth switch valve (605); the other pipeline is connected to the inlet of the concentrated solution storage tank (4) through an eighth switch valve (403); The outlet of the concentrated solution storage tank (4) is connected to the inlet of the concentrated solution feed pump (5) after passing through a sixth switch valve (401); the outlet of the ice slurry storage tank (2) is connected to the inlet of the ice slurry storage tank (2) after passing through a cold water pump (3), a cooling passage of the photovoltaic power generation panel (142) and a cold water filter (31).

3. The natural cold energy storage and conversion utilization system according to claim 1 or 2, characterized in that: the connection between the solution separator (17) and the spray tower (19) and the connection between the spray tower (19) and the fan (21) are any of the following schemes: Scheme one: an air filter (18) is arranged between the solution separator (17) and the spray tower (19), and a heat exchanger (20) is arranged between the fan (21) and the spray tower (19); the first solution pump (12) and the second solution pump (141) are connected to the spray liquid distributor (22) after passing through the heat exchanger (20); Scheme two: the solution separator (17) and the spray tower (19) are directly connected, and the heat exchanger (20) is arranged between the fan (21) and the spray tower (19), and the first solution pump (12) and the second solution pump (141) pass through the heat exchanger (20) and are connected with the spray liquid distributor (22); Scheme three: the air filter (18) is arranged between the solution separator (17) and the spray tower (19), and the fan (21) and the spray tower (19) are directly connected.

4. The use method of the natural cold energy storage and conversion utilization system according to any one of claims 1 or 3, characterized in that: when the weather is cold, the dilute solution is frozen and concentrated by the freezing and concentrating module to obtain ice and concentrated solution, the ice is stored in the ice slurry storage tank (2), and the concentrated solution is stored in the concentrated solution storage tank (4); when power is needed, the energy stored in the ice and the concentrated solution is converted into power output through energy release operation of the solution energy release module or the reverse electrodialysis energy release module.

5. The use method of the natural cold energy storage and conversion utilization system according to any one of claims 2 or 3, characterized in that: when the weather is cold, the dilute solution is frozen and concentrated by the freezing and concentrating module to obtain ice and concentrated solution, the ice is stored in the ice slurry storage tank (2), and the concentrated solution is stored in the concentrated solution storage tank (4); when there is low-price electricity at night or on the power grid, the dilute solution is concentrated for energy storage through reverse osmosis operation of the reverse osmosis energy storage and release module; when power is needed, the energy stored in the ice and the concentrated solution is converted into power output through energy release operation of the reverse osmosis energy storage and release module.

6. The use method of the natural cold energy storage and conversion utilization system according to any one of claims 4 or 5, characterized in that: the method for freezing and concentrating the dilute solution is any one of the following: Freezing and concentrating method one is as follows: Under the action of the fan (21), air flows in from the outside of the air filter (18), flows upwards through the spray tower (19), and then flows out after mixing; The dilute solution in the dilute solution storage tank (1) passes through the solution filter (13), the first solution pump (12), the solution passage of the heat exchanger (20), and then is sprayed downwards to the solution separator (17) through the liquid distributor (22), and the dilute solution is preliminarily cooled to near freezing point in the heat exchanger (20) and is further cooled and frozen into supercooled dilute solution in the spray tower (19); Freezing and concentrating method two is as follows: Under the action of the fan (21), air flows out after flowing through the air passage of the heat exchanger (20); The dilute solution in the dilute solution storage tank (1) passes through the solution filter (13), the first solution pump (12), the solution passage of the heat exchanger (20), and then is sprayed downwards to the solution separator (17) through the liquid distributor (22), and the dilute solution is cooled and frozen into supercooled dilute solution in the heat exchanger (20); Freezing and concentrating method three is as follows: Under the action of the fan (21), air flows in from the outside of the air filter (18) and flows upwards through the spray tower (19); ​ ​ ​ The dilute solution in the dilute solution storage tank (1) is sprayed and falls into the solution separator (17) through the solution filter (13), the first solution pump (12) and the liquid distributor (22), and is cooled and frozen into supercooled dilute solution in the spray tower (19); The method for separating the ice and the concentrated solution is: The supercooled dilute solution is gathered as ice slurry at the upper part of the solution separator (17) and is enriched as concentrated solution at the bottom part; the concentrated solution is sent into the concentrated solution storage tank (4) by the concentrated solution pump (16) for storage; the ice slurry is sent into the ice slurry separator (14) by the ice slurry pump (15) and is separated into ice and dilute solution; the dilute solution in the ice slurry separator (14) is combined with the dilute solution in the dilute solution storage tank (1) and is sent into the first solution pump (12) for continuing the dilute solution freezing and concentration process; and the ice is stored in the ice slurry storage tank (2).

7. The use method of the natural cold energy storage and conversion system according to claim 6, characterized in that: The method for the solution energy release module to perform the energy release operation is: The concentrated solution in the concentrated solution storage tank (4) is pressurized by the concentrated solution feed pump (5), filtered by the first concentrated solution filter (6), sent into the low-pressure side passage of the pressure exchanger (7), pressurized by the concentrated solution pressurizing pump (8) again, filtered by the second concentrated solution filter (9), and then enters the concentrated side passage of the permeation membrane (10); The liquid water in the ice slurry storage tank (2) is pressurized by the fresh water pump (201), filtered by the fresh water filter (101), sent into the fresh side passage of the permeation membrane (10), and then permeates the permeation membrane (10) to enter the concentrated side passage, mixes with the concentrated solution to become dilute solution, and flows out of the permeation membrane (10) and is divided into two streams, one of which drives the water turbine generator (11) to generate electricity and then enters the dilute solution storage tank (1) for storage, and the other of which flows through the high-pressure side passage of the pressure exchanger (7) and then enters the dilute solution storage tank (1) for storage.

8. The use method of the natural cold energy storage and conversion system according to claim 7, characterized in that: The method for the reverse osmosis energy storage and release module to perform the reverse osmosis operation is any one of the following: The reverse osmosis method one: the dilute solution in the dilute solution storage tank (1) is sent into the low-pressure side of the pressure exchanger (7) through the seventh switch valve (402), pressurized by the concentrated solution feed pump (5), filtered by the first concentrated solution filter (6), pressurized by the second concentrated solution pressurizing pump (81) again after absorbing the pressure of the high-pressure side, filtered by the second concentrated solution filter (9), and then enters the permeation membrane (10); the fresh water generated by the reverse osmosis is stored in the ice slurry storage tank (2) through the second switch valve (204), the fresh water filter (101), the one-way valve (205) and the first switch valve (202); the concentrated solution generated by the reverse osmosis enters the high-pressure side of the pressure exchanger (7) through the eleventh switch valve (603), pressurizes the dilute solution in the low-pressure side, and then is stored in the concentrated solution storage tank (4) through the eighth switch valve (403); The method for releasing energy by the reverse osmosis energy storage and release module is as follows: the liquid water in the ice slurry storage tank (2) is sent to the low-pressure side of the pressure exchanger (7) through the third switch valve (203), a concentrated solution feed pump (5), and a first concentrated solution filter (6), is pressurized, is filtered again through the first concentrated solution booster pump (8) and the second concentrated solution filter (9), and then enters the concentrated side passage of the permeation membrane (10); the fresh water generated by the reverse osmosis is stored in the ice slurry storage tank (2) through the second switch valve (204), the fresh water filter (101), the one-way valve (205), and the first switch valve (202); the concentrated solution generated by the reverse osmosis enters the high-pressure side of the pressure exchanger (7) through the eleventh switch valve (603), is pressurized after pressurizing the liquid water in the low-pressure side, and then enters the dilute solution storage tank (1) through the thirteenth switch valve (605) for storage.

9. The use method of the natural cold energy storage and conversion system according to claim 8, wherein the method for releasing energy by the reverse osmosis energy storage and release module is as follows: the concentrated solution in the concentrated solution storage tank (4) is pressurized through the sixth switch valve (401) and the concentrated solution feed pump (5), is filtered through the first concentrated solution filter (6), and then is sent to the low-pressure side of the pressure exchanger (7); after being pressurized, the concentrated solution is pressurized again through the first concentrated solution booster pump (8) and the second concentrated solution filter (9), and then enters the concentrated side passage of the permeation membrane (10); the fresh water in the ice slurry storage tank (2) flows into the fresh side passage of the permeation membrane (10) through the first switch valve (202), the fresh water pump (201), the fresh water filter (101), and the second switch valve (204), enters the concentrated side passage under the osmotic pressure, mixes with the concentrated solution, and flows out to be divided into two paths; one path enters the dilute solution storage tank (1) after driving the hydraulic turbine generator (11) to generate electricity and recover energy through the fourteenth switch valve (606); the other path flows through the high-pressure side of the pressure exchanger (7) through the eleventh switch valve (603), and then enters the dilute solution storage tank (1) for storage; meanwhile, the fresh water in the ice slurry storage tank (2) is sent to the cooling channel of the photovoltaic panel (142) by the cold water pump (3) to cool the photovoltaic cell.

10. The use method of the natural cold energy storage and conversion system according to claim 9, wherein the method for releasing energy by the reverse osmosis energy storage and release module is as follows: the concentrated solution in the concentrated solution storage tank (4) is pressurized through the concentrated solution feed pump (5) and the first concentrated solution filter (6), and is then distributed to each concentrated chamber (54); the fresh water in the ice slurry storage tank (2) is pressurized through the fresh water pump (201) and the fresh water filter (101), and is then distributed to each fresh chamber (56) to form an electric current output through an external load; the concentrated solution in the concentrated chamber (56) is reduced in concentration to become a dilute solution, the fresh water in the fresh chamber (54) is increased in concentration to become a dilute solution, and the two streams of dilute solutions are mixed and then stored in the dilute solution storage tank (1). ​ ​ ​ ​ ​ ​

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