An enhanced multi-mode multi-effect absorption type energy storage and release device and its operation method

Abstract

The present invention provides an enhanced multi-mode multi-effect absorption energy storage and release device and an operation method thereof. The device comprises: a first solution tank, a second solution tank, a refrigerant tank, a first compressor, and a second compressor. The present invention utilizes two solution tanks, two compressors, and a refrigerant tank and the connecting pipelines involved to realize an enhanced multi-mode multi-effect absorption energy storage and release cycle, which is particularly suitable for medium-temperature heat sources of 120 to 200°C, and can effectively realize the recovery of condensation heat as a concentrated heat source, realize multi-effect operation, and greatly improve the energy storage efficiency; and the present invention, with the assistance of the compressor, reduces the demand for energy storage temperature, is compatible with the use of low-temperature heat sources, and has a higher energy storage density than ordinary absorption energy storage systems. During the energy release process, by connecting the two solution tanks, it is possible to share the cooling water heat exchanger, ensure a longer energy release supply time, and achieve a stable energy release effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage, and relates to an enhanced multi-mode multi-effect absorption type energy storage and release device and an operation method thereof. Background Art

[0002] Energy crisis and environmental pollution are the focus of today's social development. The development of renewable energy has important application prospects. However, the instability and intermittency of solar energy limit its more efficient application, and energy storage technology can play an important bridging role in matching supply and demand. Absorption energy storage technology is considered to be a thermochemical energy storage method with great potential, and can be flexibly used for cooling, heating and dehumidification.

[0003] The energy storage efficiency of existing absorption energy storage devices is relatively low, generally between 0.4 and 0.9. Even if there is a high-temperature heat source, the problem of condensation heat waste has not been solved, and the energy storage efficiency cannot be improved. For example: CN103090582A discloses a supercharged three-phase absorption energy storage device, which strengthens the generation effect of the energy storage process, reduces the generation temperature required by the energy storage unit, strengthens the absorption effect of the energy release process, can increase the heating temperature during heating, can increase the energy storage density during cooling, and can achieve different cooling capacity or heating output through frequency conversion regulation. However, the device is mainly for low-temperature heat sources of 70 to 100°C, without condensation heat recovery, and when using a medium-temperature heat source of 120 to 200°C, its energy storage efficiency cannot be further improved. In addition, for traditional absorption energy storage solutions, low energy storage density and high energy storage temperature are technical obstacles that restrict its promotion and application. Summary of the invention

[0004] Based on the problems existing in the prior art, the purpose of the present invention is to provide an enhanced multi-mode and multi-effect absorption energy storage and release device. The purpose of the present invention is also to provide an enhanced double-effect absorption energy storage and release cycle method, which improves the energy storage efficiency by recovering the condensation heat and reduces the energy storage temperature by pressurization enhancement. The two together improve the energy storage density and ultimately greatly improve the utilization of solar energy.

[0005] The purpose of the present invention is achieved by the following technical means:

[0006] In one aspect, the present invention provides an enhanced multi-mode multi-effect absorption type energy storage and release device, the device comprising:

[0007] A first solution tank, a second solution tank, a refrigerant tank, a first compressor, and a second compressor;

[0008] The first solution tank is provided with a first liquid phase opening at the bottom and a first gas phase opening at the top; a first heat exchanger is provided in the first solution tank, and a first sprayer is provided on the upper part of the first heat exchanger; the first liquid phase opening is connected to the first sprayer through a pipeline;

[0009] The second solution tank is provided with a second liquid phase opening at the bottom and a second gas phase opening at the top; a second heat exchanger is provided in the second solution tank, and a second sprayer is provided on the upper part of the second heat exchanger; the second liquid phase opening is connected to the second sprayer through a pipeline; the first gas phase opening, the first compressor and the second heat exchanger are connected in sequence through pipelines;

[0010] The top of the refrigerant tank is provided with a third gas phase opening, and the side wall is provided with an opening; a third heat exchanger is provided in the refrigerant tank; the second heat exchanger is connected to the opening of the side wall of the refrigerant tank through a pipeline, and a throttle valve is provided on the connected pipeline;

[0011] The second gas phase opening, the second compressor and the third gas phase opening are sequentially connected through a pipeline;

[0012] The side walls of the first solution tank and the side walls of the second solution tank are respectively provided with openings, the two openings are connected by a pipeline, and the first solution and the second solution are interconnected or separated by a control valve on the pipeline; the second liquid phase opening is connected to the first sprayer through a pipeline; the first gas phase opening, the second compressor, and the third gas phase opening are sequentially connected through pipelines.

[0013] Since renewable resources such as solar energy have great instability and intermittency, the present invention utilizes two solution tanks, two compressors, a refrigerant tank and the connecting pipelines involved to realize an enhanced multi-mode multi-effect absorption energy storage cycle, realize high-density storage and supply-demand matching of renewable energy, and is particularly suitable for medium-temperature heat sources of 120 to 200°C, and can effectively realize the recovery of condensation heat as a concentrated heat source; during the energy storage process, the energy storage and energy release device of the present invention can recover the condensation heat generated by the first solution tank through the second solution tank, realize multi-effect operation, and thus greatly improve the energy storage efficiency; and the present invention, with the assistance of the compressor, reduces the demand for energy storage temperature, is compatible with the use of low-temperature heat sources, and has a higher energy storage density than ordinary absorption energy storage systems. During the energy release process, by connecting the two solution tanks, it is possible to share the cooling water heat exchanger (first heat exchanger), ensure a longer energy release supply time, save the heat exchanger area, and ensure the compactness and economy of the system.

[0014] In the above device, the first solution tank is loaded with the first solution, and the liquid level of the first solution is not higher than the first heat exchanger, that is, the first heat exchanger is located above the liquid level of the first solution; the second solution tank is loaded with the second solution, and the liquid level of the second solution is not higher than the second heat exchanger, that is, the second heat exchanger is located above the liquid level of the second solution. The first solution and the second solution are solutions that can be heated to generate refrigerant vapor.

[0015] In the above device, preferably, the device also includes a solar thermal collector, and the solar thermal collector is connected in series with the first heat exchanger through a pipeline.

[0016] In the above device, preferably, a heat source pump is provided on the pipeline connecting the solar thermal collector and the first heat exchanger in series.

[0017] In the above device, preferably, a first solution pump is provided on the pipeline connecting the first liquid phase opening and the first sprayer.

[0018] In the above device, preferably, a second solution pump is provided on the pipeline connecting the second liquid phase opening with the first sprayer or the second sprayer.

[0019] In the above device, preferably, at least one control valve is provided on the pipeline connecting the second solution pump and the first sprayer.

[0020] In the above device, preferably, at least one control valve is provided on the pipeline connecting the second solution pump and the second sprayer.

[0021] In the above device, preferably, the refrigerant tank is loaded with refrigerant, a third liquid phase opening is provided at the bottom of the refrigerant tank, a third sprayer is provided above the third heat exchanger, and the third liquid phase opening is connected to the third sprayer through a pipeline. The third sprayer further realizes enhanced heat exchange.

[0022] In the above device, preferably, a refrigerant pump is provided on the pipeline connecting the third liquid phase opening and the third sprayer.

[0023] The piping structures of the first heat exchanger, the second heat exchanger and the third heat exchanger used in the above-mentioned device are all coil structures; this structural arrangement is conducive to increasing the heat exchange area.

[0024] In the above device, preferably, at least one control valve is provided on the pipeline connecting the second heat exchanger and the throttle valve.

[0025] In the above device, preferably, at least one control valve is provided on the pipeline connecting the first gas phase opening and the first compressor.

[0026] In the above device, preferably, at least one control valve is provided on the pipeline connecting the second gas phase opening and the second compressor.

[0027] In the above device, preferably, at least one control valve is provided on the pipeline connecting the second compressor and the third gas phase opening.

[0028] In the above device, preferably, the first gas phase opening is connected to the second heat exchanger through a pipeline, and at least one control valve is provided on the connected pipeline.

[0029] In the above device, preferably, the second gas phase opening is connected to the third gas phase opening through a pipeline, and at least one control valve is provided on the connected pipeline.

[0030] Since the energy quality of renewable resources such as solar energy is relatively low, it is difficult to be fully utilized by ordinary absorption thermal energy storage systems. The device of the present invention includes a variety of energy storage modes and energy release modes, which can utilize weaker solar radiation energy to achieve reasonable and efficient utilization of solar energy of different intensities. According to the intensity of external solar radiation, the change of solution concentration in the solution tank, and the demand on the load side, the switch combination of the valve is adjusted to control the start and stop of the compressor, solution pump, etc., to achieve the operation of multiple energy storage modes such as non-boosting double-effect absorption energy storage mode, low-pressure boosting double-effect absorption energy storage mode, high-pressure boosting double-effect absorption energy storage mode, double-boosting double-effect absorption energy storage mode, non-boosting single-effect absorption energy storage mode, boosting single-effect absorption energy storage mode, non-boosting absorption energy release mode and boosting absorption energy release mode. Through mode switching during operation, it can flexibly adapt to changes in supply and demand side parameters, and ultimately greatly improve the utilization effect of solar energy under all working conditions, thereby achieving full, reasonable and efficient utilization of solar energy; and according to the requirements of energy release rate, a stable energy release effect can be achieved through the control of valves, compressors and solution pumps.

[0031] On the other hand, the present invention also provides a pressurized double-effect absorption energy storage and release cycle method, which is carried out using the above-mentioned device and includes the following steps:

[0032] Energy storage process: the first solution in the first solution tank is sprayed out through the first sprayer, and is heated by the external heat source through the first heat exchanger to generate high-temperature and high-pressure refrigerant vapor;

[0033] The first compressor pressurizes the high-temperature and high-pressure refrigerant vapor and transports it to the second heat exchanger in the second solution tank, while reducing the pressure in the first solution tank; the second solution in the second solution tank is sprayed out through the second sprayer, and the high-temperature and high-pressure refrigerant vapor is condensed. The heat generated heats the second solution to generate low-pressure refrigerant vapor. The condensed high-pressure refrigerant liquid is depressurized through the throttle valve and stored in the refrigerant tank;

[0034] The second compressor pressurizes the low-pressure refrigerant vapor and delivers it to the refrigerant tank, while reducing the pressure in the second solution tank. The refrigerant vapor pressurized by the second compressor exchanges heat with the cooling water in the third heat exchanger and is condensed and stored.

[0035] Energy release process: open the control valve on the connecting pipeline of the side wall opening of the first solution tank and the second solution tank to achieve the interconnection of the first solution and the second solution; at the same time, the second solution in the second solution tank is sprayed onto the first heat exchanger through the first sprayer for spray heat exchange, and the first heat exchanger is externally connected to circulating cooling water to achieve full mixing of the solutions in the first solution tank and the second solution tank; by opening the control valve on the connecting pipeline of the first gas phase opening, the second compressor and the third gas phase opening to maintain a stable energy release effect until the solution concentrations in the first solution tank and the second solution tank return to the initial concentrations before energy storage, and the energy storage and release cycle ends.

[0036] Beneficial effects of the present invention:

[0037] (1) The present invention utilizes two solution tanks, two compressors, a refrigerant tank and the related connecting pipelines to realize an enhanced multi-mode multi-effect absorption energy storage cycle, achieve high-density storage and supply-demand matching of renewable energy, and is particularly suitable for medium-temperature heat sources of 120 to 200°C, and can effectively realize the recovery of condensation heat as a concentrated heat source; during the energy storage process, the energy storage and energy release device of the present invention can recover the condensation heat generated by the first solution tank through the second solution tank, realize multi-effect operation, and thus greatly improve the energy storage efficiency; and the present invention, with the assistance of the compressor, reduces the demand for energy storage temperature, is compatible with the use of low-temperature heat sources, and has a higher energy storage density than ordinary absorption energy storage systems. During the energy release process, by connecting the two solution tanks, it is possible to share the cooling water heat exchanger, ensure a longer energy release supply time, save the heat exchanger area, and ensure the compactness and economy of the system.

[0038] (2) The device of the present invention includes a variety of energy storage modes and energy release modes, which can utilize weaker solar radiation energy to achieve reasonable and efficient utilization of solar energy of different intensities. According to the intensity of external solar radiation, the change of solution concentration in the solution tank, and the demand on the load side, the device controls the start and stop of the compressor, solution pump, etc. by adjusting the switch combination of the valve, so as to realize the operation of a variety of energy storage and energy release modes such as non-boosting double-effect absorption energy storage mode, low-pressure boosting double-effect absorption energy storage mode, high-pressure boosting double-effect absorption energy storage mode, double-boosting double-effect absorption energy storage mode, non-boosting single-effect absorption energy storage mode, boosting single-effect absorption energy storage mode, non-boosting absorption energy release mode and boosting absorption energy release mode. By switching modes during operation, it can flexibly adapt to changes in supply and demand side parameters, and ultimately greatly improve the utilization effect of solar energy under all working conditions, thereby achieving full, reasonable and efficient utilization of solar energy; and according to the requirements of energy release rate, a stable energy release effect can be achieved by controlling the valve, compressor and solution pump.

[0039] (3) The device and operation method of the present invention can reduce the initial investment on the heat source collection side under the same energy storage capacity conditions; or increase the energy storage capacity and energy output under the same heat source conditions. This technology can achieve supply and demand matching economically and efficiently, and is of great significance to the efficient use of renewable energy (especially solar energy) or industrial waste heat in building energy conservation, and can effectively promote the wider promotion and application of absorption energy storage technology and renewable energy technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a device diagram of the enhanced double-effect absorption energy storage process in Example 1 of the present invention;

[0041] Figure 2 It is a device diagram of the enhanced double-effect absorption-type energy release process in Example 1 of the present invention;

[0042] Figure 3 This is a device diagram of the non-pressurized double-effect absorption energy storage process in Example 2 of the present invention;

[0043] Figure 4 It is a device diagram of the low-pressure boosting double-effect absorption energy storage process in Example 2 of the present invention;

[0044] Figure 5 This is a pressure variation diagram of the low-pressure boosting double-effect absorption energy storage process in Example 2 of the present invention;

[0045] Figure 6 This is a pressure variation diagram of the low-pressure boosting double-effect absorption energy storage process in Example 2 of the present invention;

[0046] Figure 7 It is a device diagram of the high-pressure boosting double-effect absorption energy storage process in Example 2 of the present invention;

[0047] Figure 8 This is a device diagram of a non-pressurized single-effect absorption energy storage process in Example 2 of the present invention;

[0048] Fig. 9 This is a device diagram of the pressurized single-effect absorption energy storage process in Example 2 of the present invention;

[0049] Fig.10 It is a device diagram of the non-pressurized absorption-type energy release process in Example 2 of the present invention;

[0050] Fig.11 This is a graph showing comparative experimental results of the low-pressure boosting dual-effect absorption energy storage scheme, the traditional energy storage scheme, and the energy storage scheme of CN103090582A in Example 2 of the present invention.

[0051] Description of the accompanying symbols:

[0052] 1. Solar collector; 21. First solution tank; 22. Second solution tank; 23. Refrigerant tank; 31. First solution; 32. Second solution; 33. Refrigerant; 41. First sprayer; 42. Second sprayer; 43. Third sprayer; 51. First heat exchanger; 52. Second heat exchanger; 53. Third heat exchanger; 61. First compressor; 62. Second compressor; 701-712. Control valve; 81. Heat source pump; 82. First solution pump; 83. Second solution pump; 84. Refrigerant pump; 9. Throttle valve. DETAILED DESCRIPTION

[0053] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0054] Embodiment 1:

[0055] This embodiment provides an enhanced dual-effect absorption energy storage and release device, such as Figure 1 and Figure 2 As shown, the device comprises:

[0056] A first solution tank 21, a second solution tank 22, a refrigerant tank 23, a first compressor 61, and a second compressor 62; the first solution tank 21 is loaded with a first solution 31, a first liquid phase opening is provided at the bottom of the first solution tank 21, and a first gas phase opening is provided at the top; a first heat exchanger 51 is provided above the liquid surface of the first solution 31, and a first sprayer 41 is provided at the upper part of the first heat exchanger 51; the first liquid phase opening, the first solution pump 82 and the first sprayer 41 are sequentially connected through pipelines. The second solution tank 22 is loaded with the second solution 32, and a second liquid phase opening is provided at the bottom of the second solution tank 22, and a second gas phase opening is provided at the top; a second heat exchanger 52 is provided above the liquid surface of the second solution 32, and a second sprayer 42 is provided on the upper part of the second heat exchanger 52; the second liquid phase opening, the second solution pump 83, the control valve 711 and the second sprayer 42 are sequentially connected through pipelines; the first gas phase opening, the first control valve 701, the first compressor 61 and the second heat exchanger 52 are sequentially connected through pipelines. The refrigerant tank 23 is loaded with refrigerant 33, and a third liquid phase opening is provided at the bottom of the refrigerant tank 23, a third gas phase opening is provided at the top, and an opening is provided on the side wall; a third heat exchanger 53 is provided in the refrigerant tank 23, a third sprayer 43 is provided above the third heat exchanger 53, and the third liquid phase opening is connected to the third sprayer 43 through a pipeline; a refrigerant pump 84 is provided on the pipeline connecting the third liquid phase opening and the third sprayer 43; the second heat exchanger 52 is connected to the control valve 709, the throttle valve 9 and the opening of the side wall of the refrigerant tank 23 in sequence through a pipeline. The second gas phase opening, the control valve 704, the control valve 705, the second compressor 62, the control valve 708 and the third gas phase opening are connected in sequence through a pipeline. The pipeline structures of the first heat exchanger 51, the second heat exchanger 52 and the third heat exchanger 53 are all bent structures.

[0057] The side walls of the first solution tank 21 and the side walls of the second solution tank 22 are respectively provided with openings, the two openings are connected by a pipeline, and the first solution 31 and the second solution 32 are interconnected or separated by a control valve 712 on the pipeline; the second liquid phase opening, the second solution pump 83, the control valve 710 and the first sprayer 41 are connected in sequence through the pipeline; the first gas phase opening, the control valve 703, the control valve 707, the second compressor 62, the control valve 706 and the third gas phase opening are connected in sequence through the pipeline.

[0058] When the device performs enhanced multi-mode multi-effect absorption energy storage, the first heat exchanger 51 is connected in series with the solar collector 1 through a pipeline, and a heat source pump 81 is provided on the series pipeline; when the device performs enhanced multi-mode multi-effect absorption energy release, circulating cooling water is introduced into the first heat exchanger 51.

[0059] This embodiment also provides an enhanced dual-effect absorption-type energy storage and release cycle method, which is carried out using the above-mentioned device and includes the following steps:

[0060] (1) Energy storage process (such as Figure 1 As shown): close control valve 702, control valve 703, control valve 707, control valve 706, control valve 710 and control valve 712; open control valve 701, control valve 704, control valve 705, control valve 708, control valve 709 and control valve 711.

[0061] The first solution 31 in the first solution tank 21 is sprayed out through the first sprayer 41, and is heated by the heat source from the solar collector 1 through the first heat exchanger 51 to produce high-temperature and high-pressure refrigerant vapor; the high-temperature and high-pressure refrigerant vapor enters the first compressor 61 through the control valve 701, and the first compressor 61 is started to pressurize the high-temperature and high-pressure refrigerant vapor and transport it to the second heat exchanger 52 in the second solution tank 22, while reducing the pressure in the first solution tank 21 to enhance its generation effect; the second solution 32 in the second solution tank 22 is sprayed out through the second sprayer 42, and the high-temperature and high-pressure refrigerant vapor is condensed. The heat generated heats the second solution 32 to produce low-pressure refrigerant Steam, the condensed high-pressure refrigerant liquid flows through the control valve 709, and is reduced in pressure through the throttle valve 9 and collected and stored in the refrigerant tank 23; the low-pressure refrigerant vapor enters the second compressor 62 through the control valves 704 and 705, and the second compressor 62 is started to pressurize the low-pressure refrigerant vapor and transport it to the refrigerant tank 23 through the control valve 708, while reducing the pressure in the second solution tank 22 to enhance its generation effect, and the refrigerant vapor pressurized by the second compressor 62 exchanges heat with the cooling water in the third heat exchanger 53 and is condensed and stored, and the refrigerant pump 84 is turned on at the same time to transport the refrigerant through the third sprayer 43 for spraying to further achieve enhanced heat exchange.

[0062] During the energy storage process, the condensation heat in the first solution tank 21 is recycled by the second solution tank 22, which is beneficial to the improvement of energy storage efficiency. Moreover, under the strengthening effect of the compressor, the system's requirements for energy storage temperature are greatly reduced, so that solar energy can be fully utilized. This energy storage mode is beneficial to improving the system's energy storage efficiency and energy storage density.

[0063] (2) Energy release process (such as Figure 2 As shown): close control valve 701, control valve 702, control valve 704, control valve 705, control valve 708, control valve 709 and control valve 711; open control valve 703, control valve 707, control valve 706, control valve 710 and control valve 712.

[0064] When the control valve 712 on the connecting pipe of the side wall opening of the first solution tank 21 and the second solution tank 22 is opened, the first solution 31 and the second solution 32 are connected to each other; at the same time, the second solution 32 in the second solution tank 22 is pumped into the first sprayer 41 through the second solution pump 83 via the opened control valve 710, and sprayed onto the first heat exchanger 51 through the first sprayer 41 for spray heat exchange. The first heat exchanger 51 is externally connected to circulating cooling water; the solutions in the first solution tank 21 and the second solution tank 22 are fully mixed; in the dynamic absorption process, the change in solution concentration will cause the absorption rate to decay. In order to maintain the energy release rate, the first gas phase opening, the second compressor and the second compressor 62 on the connecting pipe of the third gas phase opening are opened in time, and at the same time, when the control valve 703, the control valve 707 and the control valve 706 are opened, the absorption process is strengthened to maintain a stable energy release effect until the solution concentrations in the first solution tank 21 and the second solution tank 22 are restored to the initial concentrations before energy storage, and the energy storage and energy release cycle ends. This energy release mode is beneficial to improving the energy release rate, increasing the output (cooling or heating) capacity, and better matching the user-side load.

[0065] Embodiment 2:

[0066] The enhanced dual-effect absorption energy storage and release device of Example 1 is further optimized to realize energy storage and release in multiple operating modes. Specifically:

[0067] A bypass pipeline is provided, the first gas phase opening is connected to the second heat exchanger 52 through the pipeline, and a control valve 702 is provided on the connected pipeline. The second gas phase opening is connected to the third gas phase opening through the pipeline, and a control valve 704 is provided on the connected pipeline and is connected to the control valve 705 and the control valve 706 in sequence.

[0068] After further optimization, the device can further realize multiple energy storage modes, including non-boosting double-effect absorption energy storage mode, low-pressure boosting double-effect absorption energy storage mode, high-pressure boosting double-effect absorption energy storage mode, double-boosting double-effect absorption energy storage mode, non-boosting single-effect absorption energy storage mode, boosting single-effect absorption energy storage mode and non-boosting absorption energy release mode. If there is no pressurization during the energy storage process, the second solution tank and the refrigerant tank are directly connected, and the pressure can be considered to be the same. The first solution tank is directly heated by the high-temperature heat source and has a higher pressure. During the energy release process, if there is no pressurization, the pressures of the three tanks are the same, and if there is pressurization, the pressure of the refrigerant tank decreases.

[0069] (1) Non-boosting double-effect absorption energy storage operation control mode:

[0070] When the solar energy is strong enough, that is, the driving temperature that can be provided to the energy storage system is high, the double-effect cycle can operate efficiently without pressurization. At this time, there is no need to start the first compressor 61 and the second compressor 62, and only the ordinary double-effect cycle can be operated. Figure 3 As shown, control valve 701, control valve 703, control valve 707, control valve 708, control valve 712 and control valve 710 are closed; control valve 702, control valve 704, control valve 705, control valve 706, control valve 709, control valve 711 and throttle valve 9 are opened.

[0071] This operation control mode fully utilizes solar energy to drive the equipment when solar radiation is strong, saving the extra power consumption of the compressor.

[0072] (2) Low-pressure boost dual-effect absorption energy storage operation control mode:

[0073] When the solar radiation intensity is not enough to drive the ordinary double-effect cycle, or the solution concentration increases and the difficulty of generation increases, the generation process on the low-pressure side (the second solution tank 22) is often difficult to maintain. At this time, the compressor on the low-pressure side (the second compressor 62) can be operated to reduce the pressure of the second solution tank 22, thereby strengthening the generation process and reducing the driving temperature required by the low-pressure side generator (the second solution tank 22). The switch combination of the control valve is as follows Figure 4 As shown, control valve 701, control valve 703, control valve 706, control valve 707, control valve 712 and control valve 710 are closed; control valve 702, control valve 704, control valve 705, control valve 708, control valve 709, control valve 711 and throttle valve 9 are opened; the first compressor 61 is closed, and the second compressor 62 is opened.

[0074] In this operation control mode, when the solar energy intensity is slightly weak, or the concentration increases and the generation rate decays in the later stage of the generation process, the second compressor 62 is used to strengthen the generation process on the low-pressure side (the second solution tank 22) to maintain the normal operation of the double-effect cycle, which not only improves the energy storage efficiency, but also helps to improve the energy storage density.

[0075] The pressure changes during the energy storage process and the energy release process are as follows: Figure 5 and Figure 6 As shown. Figure 5 and Figure 6 It can be seen that: during the energy storage process, the first solution tank is directly heated by an external heat source and has the highest pressure, so it is called a high-pressure tank; due to the pressurization of the compressor, the pressure of the refrigerant tank is higher than that of the second solution tank; during the energy release process, due to the pressurization of the compressor, the pressure of the solution tank is higher than that of the refrigerant tank.

[0076] (3) High-pressure boost dual-effect absorption energy storage operation control mode:

[0077] When the solar radiation intensity is not enough to drive the ordinary double-effect cycle, or the solution concentration increases and the difficulty of generation increases, the generation process on the low-pressure side (the second solution tank 22) is often difficult to maintain at first because the driving heat provided by the high-pressure side is insufficient. In addition to the above-mentioned low-pressure side pressurization enhancement, the high-pressure side (the first solution tank 21) can also be pressurized and enhanced by the first compressor 61, that is, more high-temperature and high-pressure steam is generated at a lower generation pressure to drive the low-pressure side generator, thereby enhancing the concentration operation on the low-pressure side. The switch combination of the control valve is as follows: Figure 7 As shown, control valve 702, control valve 703, control valve 707, control valve 708, control valve 712 and control valve 710 are closed; control valve 701, control valve 704, control valve 705, control valve 706, control valve 709, control valve 711 and throttle valve 9 are opened; the first compressor 61 is opened and the second compressor 62 is closed.

[0078] In this operation control mode, when the solar radiation intensity is slightly weak, or the concentration increases and the generation rate decays in the later stage of the generation process, the generation process on the high-pressure side (first solution tank 21) is intensified by the first compressor 61, and more high-temperature and high-pressure steam is generated to further intensify the operation of the low-pressure side (second solution tank 22), thereby maintaining the normal operation of the double-effect cycle. This mode improves the energy storage efficiency and energy storage density.

[0079] (4) Non-boosting single-effect absorption energy storage operation control mode:

[0080] When the double-effect absorption energy storage is difficult or impossible to drive even if the double boost is turned on due to weaker solar radiation intensity or higher solution concentration, it can be switched to a normal single-effect absorption energy storage cycle. Since the single-effect absorption cycle has lower driving temperature requirements than the double-effect absorption cycle, the single-effect cycle can also operate normally under unfavorable conditions. The switch combination of the control valve is as follows Figure 8 As shown, control valves 701, 702, 704, 707, 708, 709, 710, 711, 712 and throttle valve 9 are closed; control valves 703, 705 and 706 are opened; the first compressor 61 is closed and the second compressor 62 is closed. That is, the high-pressure side generator (the first solution tank 21) is directly connected to the refrigerant tank 23.

[0081] This operation control mode can greatly reduce the demand for drive temperature through the ordinary single-effect absorption energy storage cycle, which is conducive to making fuller use of solar energy and improving the energy storage density under all operating conditions.

[0082] (5) Booster single-effect absorption energy storage operation control mode:

[0083] When the solar radiation intensity is further reduced or the solution concentration is further increased, and the rate of occurrence of ordinary single-effect absorption energy storage cannot be guaranteed, the single-effect cycle can be pressurized and strengthened. Fig. 9 As shown, control valves 701, 702, 704, 707, 706, 709, 710, 711, 712 and throttle valve 9 are closed; control valves 703, 705 and 708 are opened; the first compressor 61 is closed and the second compressor 62 is opened. That is, the high-pressure side generator (the first solution tank 21) is directly connected to the refrigerant tank 23.

[0084] This operation control mode can further reduce the demand for drive temperature by boosting the single-effect absorption energy storage cycle. This mode is conducive to making full use of solar energy and improving the energy storage density under all operating conditions.

[0085] (6) Non-pressurized absorption energy release operation control mode:

[0086] During the energy release process, the first solution tank 21 and the second solution tank 22 are connected, and the second solution 32 is extracted from the second solution tank 22 and sprayed into the first heat exchanger 51 of the first solution tank 21 for spray absorption, so that the solutions in the two solution tanks are fully mixed, which not only can ensure the energy release demand for a longer time, but also saves the heat exchanger area by sharing the cooling water heat exchanger, thereby ensuring the compactness and economy of the energy storage device.

[0087] In the absorption energy release process, in the initial stage of absorption, the solution concentration is high and generally has a large absorption rate, so there is no need for the assistance of a compressor. The switch combination of the control valve is as follows: Fig.10 As shown, control valves 701, 702, 704, 707, 708, 709, 711 and throttle valve 9 are closed; control valves 703, 705, 706, 710 and 712 are opened. The first compressor 61 is closed, and the second compressor 62 is closed.

[0088] Simulation comparison experiment:

[0089] This comparative experiment compares the low-pressure boosted double-effect absorption energy storage scheme of Example 2 of the present invention, the traditional single-effect absorption energy storage scheme (scheme (4) in Example 2), and the pressurized single-effect absorption energy storage scheme disclosed in CN103090582A (Comparative Example 1).

[0090] Taking the heat source condition of 160℃ as an example, the simulation calculation results are compared. Fig.11 shown.

[0091] Depend on Fig.11It can be seen that: in terms of energy storage efficiency, compared with the 0.82 of the traditional solution, the energy storage efficiency of Example 1 is lower, which is 0.70, a decrease of 14.6%; but the low-pressure boost double-effect absorption energy storage solution of Example 2 of the present invention shows a significant improvement effect, which increases the energy storage efficiency by 81.7% to 1.49, and realizes the efficient utilization of the heat source. The reason is that there is no heat recovery in Example 1. Under the condition that the temperature of the heat source is high enough, it will be counterproductive to pressurize the system to assist. However, the low-pressure boost double-effect absorption energy storage solution of Example 2 of the present invention recovers the condensation heat. In the face of medium-temperature heat sources, it can design a double-effect or multi-effect system according to the principle of cascade utilization of energy, improve energy storage efficiency, and make full use of the heat source. In terms of energy storage density, both Example 1 and the present invention have been greatly improved compared with the traditional solution, and the improvement of the present invention is as high as 110%.

[0092] The enhanced multi-mode multi-effect absorption energy storage and release device of the present invention is not only compatible with traditional methods and the method of comparative example 1, but also can switch and be compatible with more operating modes. Moreover, the device of the present invention is particularly suitable for medium-temperature heat sources of 120 to 200°C, and can effectively realize the recovery of condensation heat as a concentrated heat source, realize multi-effect operation, and thus greatly improve the energy storage efficiency; and the present invention, with the assistance of a compressor, reduces the demand for energy storage temperature, is compatible with the use of low-temperature heat sources, and has a higher energy storage density than ordinary absorption energy storage systems. During the energy release process, by connecting the two solution tanks, the cooling water heat exchanger (first heat exchanger) is shared during the energy release process, saving the heat exchanger area, ensuring a longer energy release supply time, and ensuring the compactness and economy of the system.

Claims

1. An enhanced multi-mode multi-effect absorption type energy storage and release device, the device comprising: A first solution tank, a second solution tank, a refrigerant tank, a first compressor, and a second compressor; The first solution tank is provided with a first liquid phase opening at the bottom and a first gas phase opening at the top; a first heat exchanger is provided in the first solution tank, and a first sprayer is provided on the upper part of the first heat exchanger; the first liquid phase opening is connected to the first sprayer through a pipeline; The second solution tank is provided with a second liquid phase opening at the bottom and a second gas phase opening at the top; a second heat exchanger is provided in the second solution tank, and a second sprayer is provided on the upper part of the second heat exchanger; the second liquid phase opening is connected to the second sprayer through a pipeline; The first gas phase opening, the first compressor and the second heat exchanger are sequentially connected through pipelines; The top of the refrigerant tank is provided with a third gas phase opening, and the side wall is provided with an opening; a third heat exchanger is provided in the refrigerant tank; the second heat exchanger is connected to the opening of the side wall of the refrigerant tank through a pipeline, and a throttle valve is provided on the connected pipeline; The second gas phase opening, the second compressor and the third gas phase opening are sequentially connected through a pipeline; The side walls of the first solution tank and the side walls of the second solution tank are respectively provided with openings, the two openings are connected by a pipeline, and the first solution and the second solution are interconnected or separated by a control valve on the pipeline; the second liquid phase opening is connected to the first sprayer through a pipeline; the first gas phase opening, the second compressor, and the third gas phase opening are sequentially connected through pipelines.

2. The device according to claim 1, wherein: The device also includes a solar thermal collector, which is connected in series with the first heat exchanger through a pipeline.

3. The device according to claim 2, wherein: A heat source pump is arranged on the pipeline connecting the solar thermal collector and the first heat exchanger in series.

4. The device according to claim 1, wherein: A first solution pump is arranged on a pipeline connecting the first liquid phase opening and the first sprayer.

5. The device according to claim 1, wherein: A second solution pump is arranged on the pipeline connecting the second liquid phase opening with the first sprayer or the second sprayer.

6. The device according to claim 5, wherein: At least one control valve is arranged on the pipeline connecting the second solution pump and the first sprayer.

7. The device according to claim 5, wherein: At least one control valve is arranged on the pipeline connecting the second solution pump and the second sprayer.

8. The device according to claim 1, wherein: The refrigerant tank is loaded with refrigerant, a third liquid phase opening is arranged at the bottom of the refrigerant tank, and a third sprayer is arranged above the third heat exchanger; the third liquid phase opening is connected to the third sprayer through a pipeline.

9. The device according to claim 8, wherein: A refrigerant pump is arranged on the pipeline connecting the third liquid phase opening and the third sprayer.

10. The device according to claim 1, wherein: At least one control valve is arranged on the pipeline connecting the second heat exchanger and the throttle valve.

11. The device according to claim 1, wherein: At least one control valve is arranged on the pipeline connecting the first gas phase opening and the first compressor.

12. The device according to claim 1, wherein: At least one control valve is arranged on the pipeline connecting the second gas phase opening and the second compressor.

13. The device according to claim 1, wherein: At least one control valve is provided on the pipeline connecting the second compressor and the third gas phase opening.

14. The device according to claim 1, wherein: The first gas phase opening is connected to the second heat exchanger through a pipeline, and at least one control valve is arranged on the connected pipeline.

15. The device according to claim 1, wherein: The second gas phase opening is connected to the third gas phase opening through a pipeline, and at least one control valve is arranged on the connected pipeline.

16. An enhanced double-effect absorption-type energy storage and release cycle method, which is carried out using the device according to any one of claims 1 to 15, comprising the following steps: Energy storage process: the first solution in the first solution tank is sprayed out through the first sprayer, and is heated by the external heat source through the first heat exchanger to generate high-temperature and high-pressure refrigerant vapor; The first compressor pressurizes the high-temperature and high-pressure refrigerant vapor and transports it to the second heat exchanger in the second solution tank, while reducing the pressure in the first solution tank; the second solution in the second solution tank is sprayed out through the second sprayer, and the high-temperature and high-pressure refrigerant vapor is condensed. The heat generated heats the second solution to generate low-pressure refrigerant vapor. The condensed high-pressure refrigerant liquid is depressurized through the throttle valve and stored in the refrigerant tank; The second compressor pressurizes the low-pressure refrigerant vapor and delivers it to the refrigerant tank, while reducing the pressure in the second solution tank. The refrigerant vapor pressurized by the second compressor exchanges heat with the cooling water in the third heat exchanger and is condensed and stored. Energy release process: open the control valve on the connecting pipeline of the side wall opening of the first solution tank and the second solution tank to achieve the interconnection of the first solution and the second solution; at the same time, the second solution in the second solution tank is sprayed onto the first heat exchanger through the first sprayer for spray heat exchange, and the first heat exchanger is externally connected to circulating cooling water to achieve full mixing of the solutions in the first solution tank and the second solution tank; by opening the control valve on the connecting pipeline of the first gas phase opening, the second compressor and the third gas phase opening to maintain a stable energy release effect until the solution concentrations in the first solution tank and the second solution tank return to the initial concentrations before energy storage, and the energy storage and release cycle ends.

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