An energy storage system and method for integrating absorption refrigeration with R134a as a circulating medium

Abstract

The present invention discloses an energy storage system and method for integrated absorption refrigeration using R134a as a circulating medium. The system includes an energy storage power generation module, an absorption refrigeration module, a solar heating module, an oil tank module, and a thermochemical energy storage module. The R134a vapor outlet of the reaction absorber is connected to the R134a storage tank. The R134a vapor discharged from the R134a storage tank flows to the energy storage power generation module and the absorption refrigeration module to provide cooling and electricity. Heating and cooling in the reaction absorber are achieved through heat exchange with hot and cold oil, which is provided by the solar heating module, the oil tank module, and the thermochemical energy storage module. Using R134a refrigerant as the circulating medium for the energy storage power generation module and the absorption refrigeration module increases energy storage density. Combining the absorption refrigeration device with the compressor unit and gas storage unit of the compressed air energy storage device to form a reaction absorber allows for miniaturization of the device. The multiple energy supply meets the uninterrupted cooling and power supply needs of small residential and commercial buildings.

Description

Technical Field

[0001] The present invention belongs to the field of energy storage technology, and in particular relates to an energy storage system and method integrating absorption refrigeration with R134a as a circulating medium. Background Art

[0002] With the continuous advancement of science and technology worldwide, more and more energy is available for human use, and efforts are underway to explore new energy sources. Today, the world's energy supply is still dominated by traditional fossil fuels. Coal, oil, and natural gas account for over 80% of global energy consumption, while new energy sources such as solar energy, hydropower, wind power, and geothermal energy still account for a small proportion of global energy consumption. Furthermore, the use of traditional energy sources such as coal, oil, and natural gas is the primary source of carbon dioxide emissions. Many sectors of human life, including electricity, chemical engineering, biomedicine, and aerospace, all rely on coal, oil, and natural gas, generate carbon dioxide emissions. Energy storage technology is increasingly becoming a key player in high-tech development. Energy storage technologies can be categorized by their principles, including compressed air energy storage, pumped hydro storage, and thermochemical energy storage. However, many challenges remain in the current energy storage field. For example, while transcritical carbon dioxide energy storage in compressed air energy storage addresses the low energy storage density of air and the large gas storage caverns required for air storage, its energy storage density remains insufficient, and the equipment required for compressed air energy storage is bulky. Currently, there are limited energy storage technologies that can be miniaturized, and integrating miniaturization with cooling and heating technologies is also technically challenging. Furthermore, utilizing solar energy for power generation and cooling presents challenges with insufficient power generation and cooling capacity during periods of insufficient sunlight. Furthermore, energy storage technology is still immature in areas rich in solar and geothermal energy. Summary of the Invention

[0003] In order to solve the problems of insufficient power generation and cooling capacity when using solar energy for power generation and cooling when there is insufficient sunshine, and the large space required for compressed air energy storage, the purpose of the present invention is to provide an energy storage system and method for integrated absorption refrigeration using R134a as a circulating medium. By using refrigerant R134a simultaneously in the absorption refrigeration device and in place of air in the compressed air energy storage, the energy storage density is improved, and the absorber and generator of the absorption refrigeration device are combined with the compressor unit and gas storage unit of the compressed air energy storage device. At the same time, solar energy and thermochemical energy storage are utilized to reduce the scale of the device, thereby realizing a small-scale modular system that can be used for cooling and powering commercial and household buildings.

[0004] The present invention is achieved through the following technical solutions: an energy storage system with R134a as the circulating medium and integrated absorption refrigeration, comprising an energy storage power generation module, an absorption refrigeration module, a solar heating module, an oil tank module, and a thermochemical energy storage module; the energy storage power generation module comprises a reaction absorber, an R134a storage tank, an expansion unit, and a cooler connected in sequence, the expansion unit comprising at least two expanders, a heat exchanger being provided before each expander stage, the outlet of the cooler being connected to the absorber inlet of the reaction absorber, and the R134a vapor outlet of the reaction absorber being connected to the inlet of the R134a storage tank;

[0005] In the absorption refrigeration module, the R134a storage tank, condenser, throttle valve and evaporator are connected in sequence, the outlet of the evaporator is connected to the R134a vapor inlet of the reaction absorber, the energy storage power generation module and the absorption refrigeration module use R134a as the circulating medium, the reaction absorber uses R134a-DMETG as the working fluid pair, and R134a refrigerant and DMETG as the absorbent; an oil tank inlet heat exchanger is set at the inlet of the oil tank module, and the cold side inlet of the oil tank inlet heat exchanger is connected to the heat exchanger and the oil pipe outlet of the reaction absorber; the outlet of the oil tank module is connected to the hot oil inlet of the reaction absorber, and the cold oil inlet of the reaction absorber is connected to the cold oil pipeline; the cold side outlet of the solar heating module is connected to the hot oil inlet of the oil tank module, heat transfer oil is provided in the thermochemical energy storage module, and a plate heat exchanger is provided in the oil tank module, and the inlet and outlet of the heat transfer oil are connected to the inlet and outlet of the plate heat exchanger.

[0006] The solar heating module includes a solar heat exchanger and a first solar collector. The oil side inlet end of the solar heat exchanger is connected to the cold oil source. A solar heat exchanger inlet valve is provided at the oil side inlet of the solar heat exchanger. The oil side outlet end of the solar heat exchanger is connected to the hot oil inlet of the oil tank module. The solar heat exchanger is a shell and tube heat exchanger, and the cold and hot fluids are countercurrently exchanged.

[0007] The oil tank module includes a first oil tank and a second oil tank. The second oil tank is connected to the first oil tank through a transmission pipeline. An oil tank connecting pipeline valve is provided on the transmission pipeline. The inlet of the second oil tank is connected to the outlet of the oil tank inlet heat exchanger, and the outlet of the first oil tank serves as the outlet of the oil tank module; the heat exchanger in front of the expander uses hot oil as the heating medium, and the cold oil side of the oil tank inlet heat exchanger is connected to the oil side outlet end of the heat exchanger and the oil pipe outlet of the generator of the reaction absorber; the hot oil side of the oil tank inlet heat exchanger is connected to the absorber oil pipe outlet of the reaction absorber; the oil side inlet of the heat exchanger is connected to the first oil tank; the first oil tank and the second oil tank are coated with anti-corrosion paint.

[0008] The reaction absorber includes a generator, an absorber, a first connecting pipe heat exchanger and a second connecting pipe heat exchanger. An oil pipe is arranged between the first connecting pipe heat exchanger and the second connecting pipe heat exchanger, and a throttle valve and a pump are respectively provided below each; an annular pipe is arranged in the generator and the absorber, and the cold and hot oils flow through the annular pipe to exchange heat with the R134a-DMETG solution; the first connecting pipe heat exchanger and the second connecting pipe heat exchanger have the same structure, the oil pipe passes through the heat exchanger and exchanges heat in the heat exchanger, annular fins are provided on the outer surface of the oil pipe, and the heat exchanger shell is connected to the connecting pipe.

[0009] The thermochemical energy storage module includes a second solar collector, a solar calcination reactor, a storage tank and a thermochemical reactor connected in sequence. The solar calcination reactor stores CaCO3 solid, and the storage tank stores CaCO3, CO2 and CaO. A heat transfer oil pipe is provided in the thermochemical energy storage module, and the oil tank module is heated by circulating high-temperature heat transfer oil.

[0010] A geothermal energy storage device is also provided, the inlet of the geothermal energy storage device is connected to the cold side outlet of the condenser, and the cold side inlet of the condenser is connected to the cold oil pipe; the outlet of the geothermal energy storage device is connected to the hot oil inlet of the reaction absorber, and an outlet valve is provided at the outlet of the geothermal energy storage device.

[0011] The heat exchanger before the expander and the heat exchanger at the oil tank inlet are both shell and tube heat exchangers, and the cold and hot fluids exchange heat in countercurrent.

[0012] Based on the energy storage method of the energy storage system integrated with absorption refrigeration using R134a as the circulating medium of the present invention,

[0013] When there is sufficient sunshine, the cold oil flows from the cold oil source through the reversing valve to the solar heating module for heating and then stored in the oil tank module. The hot oil in the oil tank module flows to the absorption refrigeration module and the energy storage and discharge module.

[0014] Hot oil flows to the generator of the reaction absorber to heat the R134a-DMETG solution in the generator, so that R134a is discharged in the form of high-pressure steam and stored in the R134a storage tank; the R134a vapor is divided into two paths from the R134a storage tank and flows to the condenser and the heat exchanger before the first-stage expander respectively. One path of R134a vapor releases heat to the environment in the condenser and condenses into liquid. After the pressure and temperature are reduced by the throttle valve, it absorbs heat from the environment in the evaporator to produce a refrigeration effect. The generated R134a dry saturated vapor flows into the absorber of the reaction absorber. The other path of R134a vapor is heated by hot oil in the heat exchanger and then enters the expansion unit to generate power. After doing work, the R134a vapor enters the cooler to be cooled and then enters the absorber of the reaction absorber;

[0015] The cold oil flowing out of the generator of the reaction absorber and the cold oil flowing out of the heat exchanger before the expander enter the oil tank inlet heat exchanger together, and after heat exchange with the hot oil flowing out of the absorber of the reaction absorber, they enter the oil tank module for storage together; when there is insufficient sunlight, the R134a vapor in the R134a storage tank can continue to flow to the absorption refrigeration module and the energy storage power generation module for cooling and power supply, and the thermochemical energy storage module uses the reaction heat to heat the oil tank module.

[0016] In the reaction absorber, the reaction absorber includes a generator, an absorber, a first connecting pipe heat exchanger and a second connecting pipe heat exchanger. An oil pipe is arranged between the first connecting pipe heat exchanger and the second connecting pipe heat exchanger, and a throttle valve and a pump are respectively provided under each of them; an annular pipe is arranged in the generator and the absorber, and the hot and cold oils flow through the annular pipe to exchange heat with the R134a-DMETG solution; the first connecting pipe heat exchanger and the second connecting pipe heat exchanger have the same structure, the oil pipe passes through the heat exchanger and exchanges heat in the heat exchanger, annular fins are provided on the outer surface of the oil pipe, and the heat exchanger shell is connected to the connecting pipe; hot oil enters from the generator inlet, flows through the annular pipe in the generator to heat the R134a-DMETG solution in the generator, and the R134a vapor is discharged from the upper outlet of the generator, and the R134a-DMETG dilute solution after R134a evaporates is discharged from one side The connecting pipe is cooled and throttled and depressurized in the first heat exchanger of the connecting pipe and then flows into the absorber to absorb R134a vapor. The R134a-DMETG solution in the absorber absorbs the input R134a vapor and releases heat to the outside. The heat generated in the absorption process is taken away by the cold oil entering from the generator inlet through the annular pipe, keeping the R134a-DMETG solution in the absorber at a lower temperature so that more R134a vapor can be absorbed. The R134a-DMETG concentrated solution enters the generator through the connecting pipe on the other side after being pressurized by the pump and heated by the second heat exchanger of the connecting pipe. The cold oil cools the dilute R134a-DMETG solution flowing from the generator to the absorber in the first heat exchanger of the connecting pipe and reduces its temperature. Then, the R134a-DMETG concentrated solution flowing from the absorber to the generator is preheated in the second heat exchanger of the connecting pipe and is then discharged.

[0017] If the area where the system is located is rich in geothermal energy, a geothermal energy storage device is installed. The inlet of the geothermal energy storage device is connected to the cold side outlet of the condenser, and the cold side inlet of the condenser is connected to the cold oil pipe; the outlet of the geothermal energy storage device is connected to the hot oil inlet of the reaction absorber, and an outlet valve is set at the outlet of the geothermal energy storage device; part of the cold oil flows into the condenser from the reversing valve, absorbs the condensation heat of R134a, and is stored in the geothermal energy storage device. When there is insufficient sunlight or insufficient hot oil in the oil tank module, it directly enters the generator of the reaction absorber for heating.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] The present invention replaces air with R134a refrigerant as the circulating medium of the absorption refrigeration module and the energy storage power generation module, combines compressed air energy storage with absorption refrigeration, can provide electricity while refrigerating, reduces the overall scale of the unit, can realize the miniaturization of energy storage equipment, and combines solar energy collection and thermochemical energy storage to supply hot oil, can realize uninterrupted refrigeration and power supply, and is suitable for small household and commercial buildings; the replaced R134a refrigerant can meet the refrigeration needs of the absorption refrigeration unit on the one hand, and on the other hand, the density of R134a refrigerant is 4.25kg / m 3 , the density of air is 1.29kg / m 3 The density of R134a refrigerant is about 3.3 times that of air, so using R134a in energy storage devices has a larger energy storage density.

[0020] Furthermore, the absorber and generator of the absorption refrigeration device are combined with the compressor unit and gas storage unit in the compressed air energy storage device to form a reaction generating absorber, so that it has the functions of absorbing and evaporating R134a vapor in the absorber and generator, and increasing the pressure and storing the circulating working fluid in the compressed air energy storage.

[0021] Furthermore, geothermal energy can be used to provide hot oil when necessary, which can simultaneously meet the needs of cooling and power generation without the need for external artificial energy input, and can also meet the needs of cooling and power generation under low sunlight conditions.

[0022] In the present invention, the R134a vapor output from the generator of the reaction-generating absorber is stored in an R134a storage tank. On the one hand, this facilitates the storage of the R134a vapor, and on the other hand, it has the effect of energy storage. The R134a vapor discharged therefrom can be directly used by the refrigeration module and the energy storage power generation module. Hot oil and cold oil are used to heat the generator and take away the heat in the absorber. The oil is made to flow through an annular pipe in the generator and the absorber to increase the heat exchange rate. The cold oil passes through the connecting pipe heat exchanger between the generator and the absorber to first cool the R134a-DMETG dilute solution and then preheat the R134a-DMETG concentrated solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of an energy storage system of the present invention that uses R134a as a circulating medium and integrates absorption refrigeration.

[0024] Figure 2 Schematic diagram of an energy storage system with R134a as the circulating medium and integrated absorption refrigeration when geothermal energy is unavailable.

[0025] Figure 3 Schematic diagram of the absorber where the reaction occurs in the present invention.

[0026] Figure 4This is a schematic diagram of the connecting pipe heat exchanger of the reaction absorber in the present invention.

[0027] In the figure: 1. Reaction absorber; 2. First heat exchanger; 3. First expander; 4. Second heat exchanger; 5. Second expander; 6. Cooler; 7. Second heat exchanger oil outlet valve; 8. Generator outlet valve; 9. Absorber outlet valve; 10. First heat exchanger oil outlet valve; 11. Oil tank inlet heat exchanger; 12. Condenser; 13. Throttle valve; 14. Evaporator; 15. Inlet reversing valve; 16. Solar heat exchanger inlet valve; 17. Solar heat exchanger; 18. First solar collector; 19. First oil tank; 20. Second oil tank; 21. Oil tank connecting pipeline valve; 22. First oil tank outlet valve; 23. Thermochemical reactor; 24. Storage tank; 25. Thermochemical calcination reactor; 26. Second solar collector; 27. R134a storage tank; 28. Absorber inlet valve; 29. ​​Condenser oil side inlet valve; 30. Geothermal energy storage device; 31. Generator; 32. Absorber; 33. Connecting pipe first heat exchanger; 34. Connecting pipe throttle valve; 35. Connecting pipe second heat exchanger; 36. Connecting pipe pump. DETAILED DESCRIPTION

[0028] The invention will be described in detail below with reference to specific embodiments and the accompanying drawings.

[0029] This invention combines compressed air energy storage with absorption refrigeration, replacing air with R134a. This achieves both refrigeration and electricity generation through the expansion machine. The use of R134a refrigerant increases energy storage density. Combining the absorber and generator of the absorption refrigeration unit with the compressor unit and air storage unit of the compressed air energy storage device to form a reaction-generating absorber allows for miniaturization of the device. Furthermore, the solar thermal collection, thermochemical energy storage, and geothermal energy storage devices in the system provide hot oil for the refrigeration unit and energy storage power supply unit, meeting the uninterrupted cooling and power supply needs of small residential and commercial buildings.

[0030] like Figure 1As shown, an energy storage system with R134a as the circulating medium and integrated absorption refrigeration includes an energy storage power generation module, an absorption refrigeration module, a solar heating module, an oil tank module, a thermochemical energy storage module and a geothermal energy storage device; specifically, it includes a reaction absorber 1, a first heat exchanger 2, a first expander 3, a second heat exchanger 4, a second expander 5, a cooler 6, a second heat exchanger oil side outlet valve 7, a generator outlet valve 8, an absorber outlet valve 9, a first heat exchanger oil side outlet valve 10, an oil tank inlet heat exchanger 11, condenser 12, throttle valve 13, evaporator 14, reversing valve 15, solar heat exchanger inlet valve 16, solar heat exchanger 17, first solar thermal collector 18, first oil tank 19, second oil tank 20, oil tank connecting pipe valve 21, first oil tank outlet valve 22, thermochemical reactor 23, storage tank 24, thermochemical calcination reactor 25, second solar thermal collector 26, R134a storage tank 27, absorber inlet valve 28, condenser oil side inlet valve 29, geothermal energy storage device 30;

[0031] The energy storage and power generation module includes a reaction generating absorber 1, an R134a storage tank 27, a first heat exchanger 2, a first expander 3, a second heat exchanger 4, a second expander 5 and a cooler 6 connected in sequence; the generator outlet end of the reaction generating absorber 1 is connected to the R134a storage tank 27, and then connected to the first heat exchanger 2, the first expander 3, the second heat exchanger 4, the second expander 5 and the cooler 6 in sequence, and the outlet of the cooler 6 is connected to the absorber inlet end of the reaction generating absorber 1.

[0032] The absorption refrigeration module consists of a sequentially connected reaction absorber 1, an R134a storage tank 27, a condenser 12, a throttle valve 13, and an evaporator 14. The outlet of the evaporator 14 is connected to the inlet of the reaction absorber 1. Both the absorption refrigeration module and the energy storage power generation module include a reaction absorber and an R134a storage tank. The R134a storage tank has two outlets and an outlet valve, each connected to the R134a inlet of the condenser and the R134a inlet of the first heat exchanger. The reaction absorber 1 utilizes an R134a (1,1,1,2-tetrafluoroethane)-DMETG (dimethyl ether tetraglycol) refrigerant, with R134a as the refrigerant and DMETG as the absorbent. R134a has a boiling point of -26.5°C, far lower than DMETG's boiling point of 275.3°C. When the R134a-DMETG solution is heated, the R134a vaporizes.

[0033] The solar heating module includes a solar heat exchanger inlet valve 16, a solar heat exchanger 17 and a first solar collector 18. The cold side inlet and outlet of the first solar collector 18 are connected to the hot side inlet and outlet of the solar heat exchanger 17. The solar heat exchanger inlet valve 16 is set at the cold side inlet of the solar heat exchanger 17.

[0034] The oil tank module includes a first oil tank 19, a second oil tank 20, an oil tank inlet heat exchanger 11, an oil tank connecting pipe valve 21, and a first oil tank outlet valve 22. The first oil tank 19 and the second oil tank 20 are connected via the oil tank connecting pipe valve 21. The outlet of the first oil tank 19 is connected to the oil pipe inlet of the generator of the reaction absorber 1 via the first oil tank outlet valve 22. The cold oil side of the oil tank inlet heat exchanger 11 is respectively connected to the oil side outlet end of the first heat exchanger 2, the oil side outlet end of the second heat exchanger 4, and the oil pipe outlet of the generator of the reaction absorber 1. The hot oil side of the oil tank inlet heat exchanger 11 is connected to the absorber oil pipe outlet of the reaction absorber 1. A plate heat exchanger is installed at the bottom of the second oil tank 20.

[0035] The thermochemical energy storage module includes a thermochemical reactor 23, a storage tank 24, a thermochemical calcination reactor 25 and a second solar thermal collector 26; the second solar thermal collector 26, the thermochemical calcination reactor 25, the storage tank 24 and the thermochemical reactor 23 are connected in sequence.

[0036] The thermal energy storage device consists of an inner tube and an outer tube. The oil side outlet of the condenser is connected to the inlet of the geothermal energy storage device and is provided with an inlet valve. The oil pipe inlet end of the generator 31 of the reaction absorber 1 is connected to the outlet of the geothermal energy storage device, and the outlet of the geothermal energy storage device is provided with an outlet valve.

[0037] The first expander 3 and the second expander 5 are twin-screw expanders; the first oil tank 19 and the second oil tank 20 are coated with anti-corrosion paint; the first heat exchanger 2, the second heat exchanger 4, the oil tank inlet heat exchanger 11 and the solar heat exchanger 17 are all shell and tube heat exchangers, and the cold and hot fluids are countercurrently exchanged.

[0038] The operating method of the energy storage system integrated with absorption refrigeration using R134a as a circulating medium described in the present invention is as follows:

[0039] When there is sufficient sunshine, the cold oil flows from the cold oil source through the reversing valve 15 to the solar heat exchanger 17. After being heated by the heat storage medium heated by the first solar collector 18, it is stored in the first oil tank 19. The second solar collector 26 uses solar energy to heat and calcine the CaCO3 solid in the thermochemical calcination reactor 25, decomposing it into CaCO3, CO2 and CaO and storing it in the storage tank 24. The CO2 and CaO in this storage tank 24 can undergo carbonation reaction in the thermochemical reactor 23 to produce CaCO3. A heating pipe is provided in the thermochemical reactor 23, and a high-temperature heat-conducting oil pipeline is provided at the inlet and outlet of the heating pipe, which is connected to the bottom plate heat exchanger of the second oil tank. High-temperature heat-conducting oil at room temperature is pre-flowed into the pipeline. The large amount of heat released by the carbonation reaction can raise the temperature of the high-temperature heat-conducting oil to 500°C. The heated high-temperature heat-conducting oil flows into the bottom plate heat exchanger of the second oil tank 20 to heat the second oil tank. The high-temperature heat-conducting oil after releasing heat flows back to the thermochemical reactor 23 to absorb heat, forming a high-temperature heat-conducting oil circulation. The hot oil in the first oil tank 19 flows to the absorption refrigeration module and the energy storage and discharge module for cooling and power supply.

[0040] Hot oil from the first oil tank 19 flows to the reactive absorber 1, heating the R134a-DMETG solution in the generator 31. The R134a is discharged as high-pressure vapor and stored in the R134a storage tank 27. From the R134a storage tank 27, the R134a vapor is split into two paths, flowing to the condenser 12 and the first heat exchanger 2. One path of R134a vapor releases heat to the environment in the condenser 12, condensing into liquid. After being reduced in pressure and temperature by the throttle valve 13, it absorbs heat from the environment in the evaporator 14, generating a cooling effect. The resulting R134a dry saturated vapor flows into the absorber 32 of the reactive absorber 1. The other path of R134a vapor is further heated by the hot oil in the first heat exchanger 2, then enters the first expander 3 to generate power. After being heated again by the second heat exchanger 4, it enters the second expander 5 to generate power. The discharged R134a vapor is cooled in the cooler 6 before being discharged into the absorber 32 of the reactive absorber 1.

[0041] The cold oil flowing out of the generator 31 of the reaction absorber 1 and the cold oil flowing out of the first heat exchanger 2 and the second heat exchanger 4 are heat exchanged with the hot oil flowing out of the absorber 32 of the reaction absorber 1 in the oil tank inlet heat exchanger 11, and then enter the second oil tank 20 for storage.

[0042] When sunlight is insufficient, the R134a vapor in R134a storage tank 27 can continue to flow to the absorption refrigeration module and energy storage power generation module to provide cooling and power. Furthermore, the CO2 in storage tank 24 reacts with CaO in the thermochemical reactor to form CO2 + CaO = CaCO3. This reaction releases a large amount of heat, which is then used to heat the second oil tank 20. The heated oil can then flow into the first oil tank 19 for further storage or flow from the first oil tank 19 into the reaction absorber 1 to continue the aforementioned steps.

[0043] Preferably, if the area where the device is located is rich in geothermal energy, part of the cold oil can flow into the condenser 12 through the reversing valve 15, absorb the condensation heat of R134a, and be stored in the geothermal energy storage device 30 for insulation or heating. When there is insufficient sunlight or insufficient hot oil in the first oil tank 19, the hot oil flows directly from the geothermal energy storage device 30 into the generator 31 of the reaction absorber 1 for heating.

[0044] like Figure 2 As shown, it is an energy storage system integrating absorption refrigeration with R134a as the circulating medium when there is no geothermal energy. There is no geothermal energy storage device and condenser oil side inlet valve 29 in the system.

[0045] like Figure 3 Figure 1 shows a schematic diagram of the reaction-generating absorber according to the present invention. Hot oil enters the generator 31 inlet and flows through the generator's annular tube, heating the R134a-DMETG solution therein. R134a vapor is discharged from the upper outlet of the generator 31. After evaporation of R134a, the dilute R134a-DMETG solution flows through the left connecting pipe, is cooled by the first connecting pipe heat exchanger 33, and throttled and reduced in pressure by the connecting pipe throttle valve 34 before flowing into the absorber 32 to absorb the R134a vapor. The R134a-DMETG solution in absorber 32 absorbs the incoming R134a vapor and needs to release heat to the environment. The heat generated during the absorption process is removed by the cold oil entering the generator 31 inlet and flowing through the annular tube, maintaining a lower temperature for the R134a-DMETG solution in the absorber 31, allowing it to absorb more R134a vapor. The concentrated R134a-DMETG solution flows through the right connecting pipe, is pressurized by the connecting pipe pump 36, and heated by the second connecting pipe heat exchanger 35 before entering the generator 31. The cold oil cools the R134a-DMETG dilute solution flowing from the generator 31 to the absorber 32 in the first heat exchanger 33 of the connecting pipe to reduce its temperature, and then preheats the R134a-DMETG concentrated solution flowing from the absorber 32 to the generator 31 in the second heat exchanger 35 of the connecting pipe and is then discharged.

[0046] like Figure 4As shown, this is a schematic diagram of the connecting pipe heat exchanger of the reaction absorber in the present invention. The oil pipe passes through the heat exchanger and exchanges heat in the heat exchanger. Annular fins are provided on the outer surface of the oil pipe to enhance the heat exchange effect. The upper and lower surfaces of the heat exchanger are connected to the connecting pipe.

Claims

1. An energy storage system integrating absorption refrigeration with R134a as the circulating medium, characterized in that: The invention comprises an energy storage power generation module, an absorption refrigeration module, a solar heating module, an oil tank module and a thermochemical energy storage module; the energy storage power generation module comprises a reaction absorber (1), an R134a storage tank (27), an expansion unit and a cooler (6) connected in sequence, the expansion unit comprises at least two stages of expanders, a heat exchanger is arranged before each stage of the expander, the outlet of the cooler (6) is connected to the absorber inlet end of the reaction absorber (1), and the R134a vapor outlet of the reaction absorber (1) is connected to the inlet end of the R134a storage tank (27); In the absorption refrigeration module, the R134a storage tank (27), the condenser (12), the throttle valve (13) and the evaporator (14) are connected in sequence, the outlet of the evaporator (14) is connected to the R134a vapor inlet of the reaction absorber (1), the energy storage power generation module and the absorption refrigeration module use R134a as the circulating medium, the reaction absorber (1) uses R134a-DMETG as the working fluid pair, and uses R134a refrigerant and DMETG as the absorbent; an oil tank inlet heat exchanger is set at the inlet of the oil tank module, and the cold side inlet of the oil tank inlet heat exchanger (11) is connected to the heat exchanger and the oil pipe outlet of the reaction absorber (1); the outlet of the oil tank module is connected to the hot oil inlet of the reaction absorber (1), and the cold oil inlet of the reaction absorber (1) is connected to the cold oil pipeline; the cold side outlet of the solar heating module is connected to the oil The hot oil inlet of the tank module, the thermal oil is provided in the thermochemical energy storage module, the plate heat exchanger is provided in the oil tank module, and the inlet and outlet of the thermal oil are connected to the inlet and outlet of the plate heat exchanger; the reaction generating absorber comprises a generator (31), an absorber (32), a first connecting pipe heat exchanger (33) and a second connecting pipe heat exchanger (35), an oil pipe is arranged between the first connecting pipe heat exchanger (33) and the second connecting pipe heat exchanger (35), and a throttle valve and a pump are respectively provided below each; an annular pipe is arranged in the generator (31) and the absorber (32), and the hot and cold oils flow through the annular pipe to exchange heat with the R134a-DMETG solution; the first connecting pipe heat exchanger (33) and the second connecting pipe heat exchanger (35) have the same structure, the oil pipe passes through the heat exchanger and exchanges heat in the heat exchanger, an annular fin is provided on the outer surface of the oil pipe, and the heat exchanger shell is connected to the connecting pipe.

2. The energy storage system with R134a as the circulating medium integrated absorption refrigeration according to claim 1 is characterized in that: The solar heating module comprises a solar heat exchanger (17) and a first solar heat collector (18); the oil-side inlet end of the solar heat exchanger (17) is connected to a cold oil source; a solar heat exchanger inlet valve is provided at the oil-side inlet of the solar heat exchanger (17); the oil-side outlet end of the solar heat exchanger (17) is connected to a hot oil inlet of an oil tank module; the solar heat exchanger (17) is a shell-and-tube heat exchanger, and cold and hot fluids exchange heat in countercurrent.

3. The energy storage system with R134a as the circulating medium and integrated absorption refrigeration according to claim 1 is characterized in that: The oil tank module comprises a first oil tank (19) and a second oil tank (20), the second oil tank is connected to the first oil tank through a transmission pipeline, an oil tank connecting pipeline valve (21) is provided on the transmission pipeline, the inlet of the second oil tank (20) is connected to the outlet of the oil tank inlet heat exchanger (11), and the outlet of the first oil tank (19) serves as the outlet of the oil tank module; the heat exchanger before the expander uses hot oil as a heating medium, the cold oil side of the oil tank inlet heat exchanger (11) is connected to the oil side outlet end of the heat exchanger and the oil pipe outlet of the generator of the reaction absorber (1); the hot oil side of the oil tank inlet heat exchanger (11) is connected to the absorber oil pipe outlet of the reaction absorber (1); the oil side inlet of the heat exchanger is connected to the first oil tank; the first oil tank and the second oil tank are coated with anti-corrosion paint.

4. The energy storage system with R134a as the circulating medium and integrated absorption refrigeration according to claim 1 is characterized in that: The thermochemical energy storage module includes a second solar collector, a solar calcination reactor, a storage tank and a thermochemical reactor connected in sequence. The solar calcination reactor stores CaCO3 solid, and the storage tank stores CaCO 3、 CO2 and CaO; A heat transfer oil pipe is provided in the thermochemical energy storage module, and the oil tank module is heated by circulating high-temperature heat transfer oil.

5. The energy storage system with R134a as the circulating medium and integrated absorption refrigeration according to claim 1 is characterized in that: A geothermal energy storage device is also provided, the inlet of the geothermal energy storage device is connected to the cold side outlet of the condenser (12), and the cold side inlet of the condenser (12) is connected to the cold oil pipe; the outlet of the geothermal energy storage device is connected to the hot oil inlet of the reaction absorber (1), and an outlet valve is provided at the outlet of the geothermal energy storage device.

6. The energy storage system with R134a as the circulating medium and integrated absorption refrigeration according to claim 1 is characterized in that: The heat exchanger before the expander and the heat exchanger at the oil tank inlet are both shell and tube heat exchangers, and the cold and hot fluids exchange heat in countercurrent.

7. An energy storage method for an energy storage system integrated with absorption refrigeration using R134a as a circulating medium according to any one of claims 1 to 6, characterized in that: When there is sufficient sunshine, the cold oil flows from the cold oil source through the reversing valve to the solar heating module for heating and then stored in the oil tank module. The hot oil in the oil tank module flows to the absorption refrigeration module and the energy storage and discharge module. Hot oil flows to the generator of the reaction absorber to heat the R134a-DMETG solution in the generator, so that R134a is discharged in the state of high-pressure steam and stored in the R134a storage tank; the R134a vapor is divided into two paths from the R134a storage tank and flows to the condenser and the heat exchanger before the first-stage expander respectively. One path of R134a vapor releases heat to the environment in the condenser and condenses into liquid. After passing through the throttle valve (13) to reduce pressure and temperature, it absorbs heat from the environment in the evaporator (14) to produce a cooling effect. The generated R134a dry saturated vapor flows into the absorber of the reaction absorber (1). The other path of R134a vapor is heated by hot oil in the heat exchanger and then enters the expansion unit to generate power. After the power is generated, the R134a vapor enters the cooler (6) to be cooled and then enters the absorber of the reaction absorber (1); The cold oil flowing out of the generator of the reaction absorber (1) and the cold oil flowing out of the heat exchanger in front of the second-stage expander enter the oil tank inlet heat exchanger together, and after heat exchange with the hot oil flowing out of the absorber of the reaction absorber, enter the oil tank module for storage together; when the sunshine is insufficient, the R134a vapor in the R134a storage tank can continue to flow to the absorption refrigeration module and the energy storage power generation module for cooling and power supply, and the thermochemical energy storage module uses the reaction heat to heat the oil tank module.

8. The energy storage method according to claim 7, characterized in that: In the reaction absorber, hot oil enters from the generator inlet, flows through the annular tube in the generator to heat the R134a-DMETG solution in the generator, and the R134a vapor is discharged from the upper outlet of the generator. After R134a evaporates, the R134a-DMETG dilute solution flows from the connecting pipe on one side and is cooled and throttled and depressurized in the first heat exchanger of the connecting pipe, and then flows into the absorber to absorb the R134a vapor. The R134a-DMETG solution in the absorber absorbs the input R134a vapor and releases heat to the outside. The heat generated in the absorption process is absorbed by the R134a vapor from the generator inlet. The cold oil entering the inlet flows through the annular pipe and is taken away to keep the R134a-DMETG solution in the absorber at a lower temperature so as to absorb more R134a vapor. The R134a-DMETG concentrated solution enters the generator through the connecting pipe on the other side after being pressurized by the pump and heated by the second heat exchanger of the connecting pipe; the cold oil cools the R134a-DMETG dilute solution flowing from the generator to the absorber in the first heat exchanger of the connecting pipe, and then preheats the R134a-DMETG concentrated solution flowing from the absorber to the generator in the second heat exchanger of the connecting pipe and is then discharged.

9. The energy storage method according to claim 7, characterized in that: When the area where the system is located is rich in geothermal energy, a geothermal energy storage device is installed. The inlet of the geothermal energy storage device is connected to the cold side outlet of the condenser (12), and the cold side inlet of the condenser (12) is connected to the cold oil pipe; the outlet of the geothermal energy storage device is connected to the hot oil inlet of the reaction absorber (1), and an outlet valve is installed at the outlet of the geothermal energy storage device; part of the cold oil flows into the condenser from the reversing valve, absorbs the condensation heat of R134a, and is stored in the geothermal energy storage device. When there is insufficient sunlight or insufficient hot oil in the oil tank module, the cold oil directly enters the generator of the reaction absorber for heating.

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