Energy storage cabinet

Abstract

The present invention discloses an energy storage cabinet, comprising: a direct cooling system comprising: a direct cooling refrigerant pipeline, both ends of which are respectively connected to a heat regenerator; a direct cooling component connected to the direct cooling refrigerant pipeline; a second throttling component located on the liquid outlet side of the direct cooling component; a pressure detection element located on the liquid outlet side of the direct cooling component; a temperature detection element located on the liquid outlet side of the direct cooling component; and a controller configured to: obtain temperature values ​​and pressure values ​​corresponding to the temperature detection element and the pressure detection element; obtain the refrigerant saturation temperature corresponding to the pressure value; and control the opening of the second throttling component through a PID control algorithm according to the refrigerant saturation temperature and the temperature value. The energy storage cabinet proposed by the present invention controls the opening of the second throttling component on the liquid outlet side of the direct cooling component to ensure that the refrigerant at the liquid outlet of the direct cooling component is in a gas-liquid two-phase state, thereby ensuring the temperature uniformity of the direct cooling component and ensuring the uniformity of heat dissipation of the battery cell.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage, and in particular to an improvement of an energy storage cabinet. Background Art

[0002] Energy storage cabinets generate a significant amount of heat during use. If this heat isn't dissipated promptly, the temperature inside the cabinet will gradually rise. When the temperature reaches a certain level, it will affect the cabinet's functionality (such as charging and discharging performance), and even pose a risk of explosion. Furthermore, in extremely low ambient temperatures, such as in winter, the batteries can suffer from severe power loss, improper charging and discharging, and a shortened lifespan. Therefore, commercial energy storage cabinets are typically equipped with refrigeration units to cool the batteries and keep them within a suitable temperature range.

[0003] The main heat dissipation method of existing energy storage cabinets is to control the temperature of the battery through a liquid cooling unit, which mainly cools the battery cells. After the refrigeration system converts heat into cold, it undergoes secondary heat exchange in the water system, with the outlet water temperature of 18°C ​​as the control target to cool or heat the battery liquid cooling plate. The temperature of the battery liquid cooling plate is unstable, and the temperature uniformity of the battery cell cooling is poor.

[0004] The above information disclosed in this background technology is only used to increase the understanding of the background technology of this application. Therefore, it may contain information that does not constitute the prior art known to ordinary technicians in this field. Summary of the Invention

[0005] In response to the problems pointed out in the background technology, the energy storage cabinet proposed in the present invention is equipped with a direct cooling system. By controlling the opening of the second throttling component on the liquid outlet side of the direct cooling component, the refrigerant at the liquid outlet of the direct cooling component is ensured to be in a gas-liquid two-phase state, thereby ensuring the temperature uniformity of the direct cooling component and the uniformity of the heat dissipation of the battery cell.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0007] In some embodiments of the present application, an energy storage cabinet is provided, comprising:

[0008] A cabinet body is formed with a battery compartment formed therein, wherein an energy storage battery is arranged in the battery compartment, and the energy storage battery includes a battery cell;

[0009] Direct cooling system: It is formed by connecting the compressor, condenser, regenerator and direct cooling components through refrigerant pipelines, including:

[0010] Direct cooling refrigerant pipeline, both ends of which are connected to the regenerator;

[0011] A direct cooling component, connected to the direct cooling refrigerant pipeline, arranged in the battery compartment, and used to cool the battery cells;

[0012] a second throttling component connected to the direct cooling refrigerant pipeline and located on the liquid outlet side of the direct cooling component;

[0013] a pressure detection element connected to the direct cooling refrigerant pipeline and located on the liquid outlet side of the direct cooling component;

[0014] a temperature detection element connected to the direct cooling refrigerant pipeline and located on the liquid outlet side of the direct cooling component;

[0015] The controller communicates with at least the second throttling component, the temperature detection element, and the pressure detection element, and is configured as follows:

[0016] Obtain the temperature and pressure values ​​corresponding to the temperature detection element and the pressure detection element;

[0017] The refrigerant saturation temperature corresponding to the pressure value is obtained through the refrigerant saturation temperature table pre-stored in it;

[0018] The opening of the second throttling component is controlled by the PID control algorithm according to the pre-existing internal target temperature difference, the refrigerant saturation temperature and the temperature value, so that the refrigerant at the liquid outlet of the direct cooling component remains in a gas-liquid two-phase state.

[0019] In some embodiments of the present application, the controller is further configured to:

[0020] After detecting that the second throttle component is powered on, a signal is sent to the second throttle component to control the second throttle component to maintain an initial opening value for a preset time;

[0021] Obtain the opening degree of the second throttling component, the temperature value of the temperature detection element, and the refrigerant saturation temperature corresponding to the pressure detection element corresponding to the last adjustment, as well as the temperature value of the temperature detection element and the refrigerant saturation temperature corresponding to the pressure detection element corresponding to the current adjustment, and obtain the opening value of the second throttling component that needs to be opened this time through the PID control algorithm;

[0022] The controller controls the opening of the second throttling component to a desired opening value within a preset opening range and with a preset number of valve adjustment steps.

[0023] In some embodiments of the present application, the controller is further configured to:

[0024] The operation mode of the energy storage cabinet is obtained before controlling the opening of the second throttling component. When it is obtained that the energy storage cabinet is in the cooling operation mode and the cooling operation time is greater than the first preset time, the opening of the second throttling component is controlled.

[0025] In some embodiments of the present application, the controller is configured as follows:

[0026] The opening of the second throttling component is adjusted once every time period T.

[0027] In some embodiments of the present application, the present invention further includes: a compressor oil return circuit, wherein the compressor oil return circuit is formed by connecting the compressor, the oil separator, the filter, the oil return capillary tube and the gas-liquid separator through the oil return refrigerant pipe.

[0028] In some embodiments of the present application, further comprising:

[0029] The compressor unloading and relief circuit is formed by connecting the compressor, unloading solenoid valve, unloading capillary tube and gas-liquid separator through the pressure relief refrigerant pipe.

[0030] In some embodiments of the present application, the direct cooling component includes:

[0031] Upper cover;

[0032] A bottom plate, wherein the bottom plate and the upper cover are combined to form a refrigerant flow channel;

[0033] A connector is formed with an inlet channel communicating with the inlet of the refrigerant flow path and an outlet channel communicating with the outlet of the refrigerant flow path.

[0034] In some embodiments of the present application, a refrigerant flow channel with a top opening is formed on the bottom plate, and the upper cover is buckled on the bottom plate to block the top opening and constitute the refrigerant flow channel together with the refrigerant flow channel.

[0035] In some embodiments of the present application, the refrigerant flow channel is symmetrically arranged with the left and right width center lines of the direct cooling component as the symmetry axis;

[0036] The refrigerant flow channel is divided into two groups of refrigerant channels symmetrically along the center line of the direct cooling component;

[0037] Each group of refrigerant channels includes a side refrigerant channel group and an intermediate refrigerant channel group, and the two groups of intermediate refrigerant channels are arranged adjacent to each other;

[0038] When the refrigerant flows in, it flows from the side refrigerant channel groups at both sides, then enters the intermediate refrigerant channel groups of its corresponding group, flows along the intermediate refrigerant channel groups, and finally flows out of the intermediate refrigerant channel groups. The outlets of the two intermediate refrigerant channel groups meet.

[0039] In some embodiments of the present application, an air-conditioning compartment is further formed inside the cabinet, and the compressor, condenser and regenerator are all arranged in the air-conditioning compartment.

[0040] Compared with the prior art, the advantages and positive effects of the present invention are:

[0041] In the energy storage cabinet of this embodiment, the controller obtains the pressure value of the pressure detection element and the matching refrigerant saturation temperature and temperature value of the temperature detection element, and controls the opening of the second throttling component through the PID control algorithm to ensure that the refrigerant flowing out of the direct cooling component is in a gas-liquid two-phase state, thereby ensuring that the temperature difference of the direct cooling component is within the preset temperature difference range, achieving temperature uniformity control of the direct cooling component, and also achieving uniformity in cooling and dissipating the energy storage battery cells, with good heat dissipation effect on the cells. Compared with the liquid cooling heat dissipation method, the heat dissipation effect is obvious.

[0042] Other features and advantages of the present invention will become more apparent after reading the detailed description of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0044] Figure 1 is a schematic diagram of a direct cooling system of an energy storage cabinet according to an embodiment;

[0045] Figure 2 A cycle diagram of a direct cooling system for an energy storage cabinet according to an embodiment;

[0046] Figure 3 This is a temperature difference curve diagram of the corresponding battery cells when the refrigerant at the liquid outlet of the direct cooling component of the energy storage cabinet according to the embodiment is in gas-liquid two-phase and superheated gas;

[0047] Figure 4 This is a cloud diagram of the surface temperature of a direct cooling component of a direct cooling system of an energy storage cabinet according to an embodiment;

[0048] Figure 5 A surface temperature cloud diagram of a region where a direct cooling component of a direct cooling system of an energy storage cabinet is provided with battery cells according to an embodiment;

[0049] Figure 6 A temperature cloud diagram of a battery cell cooled by a direct cooling system of an energy storage cabinet according to an embodiment;

[0050] Figure 7 A cross-sectional temperature cloud diagram of an energy storage cell cooled by a direct cooling system of an energy storage cabinet according to an embodiment;

[0051] Figure 8 is a structural exploded view of a direct cooling component of an energy storage cabinet according to an embodiment;

[0052] Figure 9is a three-dimensional structural diagram of an energy storage cabinet according to an embodiment;

[0053] Figure 10 FIG1 is a structural diagram of battery cells arranged in an energy storage cabinet according to an embodiment.

[0054] Reference numerals:

[0055] Among them, 100, compressor; 200, condenser; 300, regenerator; 400, main refrigerant pipeline; 510, direct cooling component; 511, upper cover; 512, bottom plate; 513, connector; 514, side refrigerant channel group; 515, intermediate refrigerant channel group; 520, direct cooling refrigerant pipeline; 521, liquid inlet side; 522, liquid outlet side; 530, first throttling component; 540, liquid inlet side temperature sensor; 550, second throttling component; 560, temperature detection element; 570, pressure detection element; 580, one-way valve; 600, high-pressure liquid storage tank; 810, oil separator; 820, return oil capillary; 830, gas-liquid separator; 840, unloading capillary; 900, cabinet; 910, battery compartment; 920, energy storage battery; 930, partition; 940, air conditioning compartment. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0057] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0058] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0059] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0060] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0061] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0062] In some embodiments of the present application, an energy storage cabinet is provided, comprising:

[0063] A cabinet 900 is formed with a battery compartment 910 , and an energy storage battery 920 is disposed in the battery compartment 910 ;

[0064] In some embodiments, a partition is provided inside the cabinet 900, which divides the cabinet 900 into a plurality of battery compartments 910 arranged vertically and having an opening on the front side. Energy storage batteries 920 are placed in the battery compartments 910 for battery storage.

[0065] The energy storage battery 920 includes a main part, a battery cell. When the energy storage battery 920 is charged or discharged, the battery cell will generate heat.

[0066] The energy storage cabinet generates a large amount of heat during use. If this heat is not dissipated in time, the temperature inside the cabinet will gradually rise. When the temperature rises to a certain level, it will affect the use function (such as charging and discharging performance) of the battery located inside the cabinet 900, and even worse, there is a risk of explosion.

[0067] At the same time, when the ambient temperature is too low, such as in winter, the low temperature environment will also cause the battery to have serious power loss, cannot be charged and discharged normally, and shortened life.

[0068] In order to cool down and dissipate heat from the energy storage cells, the main heat-generating components in the battery, a direct cooling system for heat dissipation is installed in the energy storage cabinet. The direct cooling system directly introduces refrigerant and dissipates heat from the cells directly through the refrigerant to achieve rapid cooling and heat dissipation effects.

[0069] Direct cooling system: It is formed by the compressor 100, the condenser 200, the regenerator 300 and the direct cooling component 510 connected by a refrigerant pipeline. The direct cooling system is mainly used to cool and dissipate heat to the battery cells.

[0070] When connected, the compressor 100 , the condenser 200 , and the regenerator 300 are connected in series via the main refrigerant pipeline 400 .

[0071] The compressor 100 , the condenser 200 and the regenerator 300 are connected in sequence, the regenerator 300 is connected to the compressor 100 , and the high-pressure liquid storage tank 600 is connected between the condenser 200 and the regenerator 300 .

[0072] In some embodiments of the present application, the direct cooling system also includes a compressor 100 oil return circuit, which is formed by connecting the compressor 100, the oil separator 810, the filter, the return oil capillary 820 and the gas-liquid separator 830 through an oil return refrigerant pipe.

[0073] The refrigerant flowing out of the compressor 100 can be separated by the oil separator 810 and enter the filter, then flow into the return oil capillary 820, flow from the return oil capillary 820 into the gas-liquid separator 830, and finally flow back to the compressor 100 through the gas-liquid separator 830.

[0074] In some embodiments of the present application, the direct cooling system further includes:

[0075] The compressor unloading circuit is formed by connecting the compressor 100, the unloading solenoid valve, the unloading capillary tube 840 and the gas-liquid separator 830 through the unloading refrigerant pipe.

[0076] When high-pressure unloading is required, the unloading solenoid valve can be opened to connect the compressor unloading circuit. In this way, the high-temperature and high-pressure refrigerant flowing out of the compressor 100 can pass through the unloading solenoid valve into the unloading capillary 840 for high-pressure unloading, and then enter the gas-liquid separator 830, and finally flow back to the compressor 100 through the gas-liquid separator 830 to protect the compressor 100.

[0077] In some embodiments of the present application, the direct cooling system includes:

[0078] The direct cooling refrigerant pipeline 520 is connected to the regenerator 300 at both ends;

[0079] The direct cooling refrigerant pipeline 520 is connected to the liquid outlet and liquid return ends of the regenerator 300 to achieve connection with the main refrigerant pipeline 400 to ensure that the refrigerant in the main refrigerant pipeline 400 can be transported to the direct cooling refrigerant pipeline 520 for heat exchange.

[0080] The direct cooling component 510 is connected to the direct cooling refrigerant pipeline 520 and is arranged in the battery compartment 910 .

[0081] The refrigerant input into the direct cooling component 510 can evaporate and absorb heat when passing through the direct cooling component 510. The evaporation and heat absorption of the refrigerant in the direct cooling component 510 can cool the battery cells of the energy storage battery 920, thereby achieving the effect of changing and regulating the battery cell temperature.

[0082] In some embodiments of the present application, a first throttling component 530 is provided on the direct cooling refrigerant pipeline 520, located on the liquid inlet side 521 of the direct cooling component 510, for throttling and reducing the pressure of the refrigerant entering the direct cooling component 510.

[0083] The first throttling component 530 is a first electronic expansion valve, which can throttle and reduce the pressure of the refrigerant that is about to enter the direct cooling component 510.

[0084] The liquid inlet temperature sensor 540 is disposed on the liquid inlet side of the direct cooling refrigerant pipeline 520 .

[0085] The second throttling component 550 is connected to the direct cooling refrigerant pipeline 520 and is located at the liquid outlet side 522 of the direct cooling component 510 .

[0086] The second throttling component 550 is a second electronic expansion valve. When in use, the state of the refrigerant at the liquid outlet of the direct cooling component 510 can be controlled by controlling the opening value of the second throttling component 550.

[0087] When the refrigerant state at the liquid outlet of the direct cooling component 510 is a gas-liquid two-phase state, the temperature difference of the direct cooling component 510 can be guaranteed to be within the preset temperature difference range, so that the surface temperature fluctuation of the direct cooling component 510 is small, and the temperature uniformity of the direct cooling component 510 is achieved, thereby ensuring the uniformity of its cooling of the battery cells of the energy storage battery 920, so as to ensure uniform cooling of the battery cells and the cooling effect of the battery cells.

[0088] In addition, a direct cooling component 510 is provided so that the supercooled refrigerant flowing out of the regenerator 300 can evaporate and absorb heat when entering the direct cooling component 510, so as to directly contact with the battery cell through the direct cooling component 510 for cooling and heat exchange, directly absorbing the heat from the battery cell, with a fast cooling speed and a good cooling effect.

[0089] In some embodiments of the present application, the preset temperature difference range of the direct cooling component 510 is between 0-2°C.

[0090] By controlling the opening of the second throttling component 550, the refrigerant at the liquid outlet of the direct cooling component 510 can be in a gas-liquid two-phase state.

[0091] When the refrigerant at the liquid outlet of the direct cooling component 510 is in an overheated gaseous state, the surface temperature difference of the direct cooling component 510 will vary greatly, and the surface temperature of the direct cooling component 510 will be unstable, which cannot meet the effect of uniformly cooling the battery cells of the energy storage battery 920.

[0092] Reference Figure 3 As shown, Figure 3 The refrigerant at the liquid outlet of the direct cooling component 510 indicated in medium red is superheated gas.

[0093] As time goes by, the maximum temperature difference of the battery cells of the corresponding energy storage battery 920 fluctuates linearly and continues to rise. Therefore, when the discharged refrigerant at the liquid outlet of the direct cooling component 510 is superheated gas, its cooling and heat dissipation effect on the battery cells is poor and the cooling uniformity and stability are poor.

[0094] When the refrigerant at the liquid outlet of the direct cooling component 510 is gas-liquid two-phase, it can be seen that as the heat dissipation time increases, the temperature difference fluctuation range of the battery cell of the energy storage battery 920 is very small, and the temperature difference is almost maintained within a relatively stable temperature difference range.

[0095] This means that when the refrigerant dryness at the liquid outlet of the direct cooling component 510 is in a gas-liquid two-phase state, the surface temperature of the direct cooling component 510 is uniform and stable, and its heat dissipation effect on the energy storage battery cell is also uniform. It can also be seen from the figure that the temperature difference fluctuation of the energy storage battery cell is very small and remains within a smaller temperature difference fluctuation range, ensuring the uniformity of the heat dissipation of the energy storage battery 920.

[0096] Therefore, by controlling the opening of the second throttling component 550, the dryness of the refrigerant at the liquid outlet of the direct cooling component 510 is controlled, thereby ensuring the temperature uniformity of the direct cooling component 510 and ensuring its heat dissipation effect on the energy storage battery cell.

[0097] Reference for refrigerant flow process of direct cooling system Figure 2 As shown: R134a refrigerant is compressed by the compressor 100 into a high-temperature and high-pressure gaseous refrigerant. After passing through the oil return circuit of the oil separator compressor 100 and the high-pressure unloading protection of the unloading circuit of the compressor 100, the refrigerant enters the condenser 200 for cooling and heat dissipation to become a medium-temperature and high-pressure liquid refrigerant. After passing through the high-pressure liquid storage tank 600 and the regenerator 300, it becomes a high-pressure supercooled liquid refrigerant.

[0098] The refrigerant passes through the first throttling component 530 on the liquid inlet side 521 of the direct cooling component 510, is throttled and reduced in pressure, and then enters the direct cooling component 510 to evaporate and absorb heat to cool the battery cells of the energy storage battery 920. The gas-liquid two-phase refrigerant output after cooling flows out from the liquid outlet of the direct cooling component 510, and then the gas-liquid two-phase refrigerant evaporates after passing through the regenerator 300, and then returns to the compressor 100 through the low-pressure gas-liquid separator 830, completing the mechanical compression refrigerant cycle.

[0099] The pressure detection element 570 is connected to the direct cooling refrigerant pipeline 520 and is located on the liquid outlet side 522 of the direct cooling component 510;

[0100] The pressure detection element 570 is a pressure detection sensor, which can be used to detect in real time the pressure value of the refrigerant flowing out of the direct cooling component 510 after heat exchange.

[0101] The temperature detection element 560 is connected to the direct cooling refrigerant pipeline 520 and is located on the liquid outlet side 522 of the direct cooling component 510. The temperature detection element 560 is a temperature detection sensor, which is used to detect the temperature value of the refrigerant after heat exchange flowing out of the direct cooling component 510.

[0102] In some embodiments of the present application, a temperature sensor on the liquid inlet side 521 is further included, which is arranged on the direct cooling refrigerant pipeline 520 and is used to detect the temperature of the refrigerant to enter the direct cooling component 510.

[0103] In some embodiments of the present application, a one-way valve 580 is provided on the direct cooling refrigerant pipeline 520 , which can be used to individually control the direct cooling refrigerant pipeline 520 .

[0104] In some embodiments of the present application, shut-off valves are provided on the direct cooling refrigerant pipelines 520 at both sides of the direct cooling component 510 for implementing shut-off control.

[0105] The controller communicates with at least the second throttling component 550 , the temperature detection element 560 , and the pressure detection element 570 .

[0106] The controller communicates with the second throttle component 550 and can be used to obtain the opening of the second throttle component 550 in real time and control the opening and closing of the second throttle component 550.

[0107] The controller can obtain the pressure value and temperature value of the refrigerant flowing out of the direct cooling component 510 in real time by communicating with the temperature detection element 560 and the pressure detection element 570 .

[0108] The controller configuration is:

[0109] Obtaining the temperature value and pressure value corresponding to the temperature detection element 560 and the pressure detection element 570;

[0110] The refrigerant saturation temperature corresponding to the pressure value is obtained through the refrigerant saturation temperature table pre-stored in it;

[0111] The refrigerant saturation temperature table is an existing known table, and each pressure value can be queried for a corresponding refrigerant saturation temperature.

[0112] The refrigerant saturation temperature corresponding to the detected pressure value can be obtained.

[0113] The controller controls the opening of the second throttling component 550 through the PID control algorithm according to the pre-existing internal target temperature difference, refrigerant saturation temperature and temperature value, so that the refrigerant at the liquid outlet of the direct cooling component 510 remains in a gas-liquid two-phase state, which is to control the refrigerant dryness.

[0114] During setting, the target temperature difference can be set to = refrigerant saturation temperature - temperature value of the liquid outlet side 522 of the direct cooling component 510 = 0. During adjustment, the opening of the second throttling component 550 is adjusted by taking the refrigerant saturation temperature as the adjustment target, so that the refrigerant temperature value of the liquid outlet side 522 of the direct cooling component 510 is infinitely close to the refrigerant saturation temperature, that is, the target temperature difference is close to 0.

[0115] By controlling the opening of the second throttling component 550 so that the difference between the refrigerant saturation temperature and the refrigerant temperature on the liquid outlet side 522 of the direct cooling component 510 is close to the target temperature difference, the refrigerant flowing out of the liquid outlet of the direct cooling component 510 is in a gas-liquid two-phase state, thereby ensuring that the temperature difference of the direct cooling component 510 is within the preset temperature difference range, so as to ensure a uniform cooling and heat dissipation effect on the battery cells of the energy storage battery 920.

[0116] In the energy storage cabinet of this embodiment, the controller obtains the pressure value of the pressure detection element 570 and the matching refrigerant saturation temperature and the temperature value of the temperature detection element 560, and controls the opening of the second throttling component 550 through the PID control algorithm to ensure that the refrigerant flowing out of the direct cooling component 510 is in a gas-liquid two-phase state, thereby ensuring that the temperature difference of the direct cooling component 510 is within a preset temperature difference range, achieving temperature uniformity control of the direct cooling component 510, and also achieving uniform cooling and heat dissipation of the battery cells of the energy storage battery 920, with good heat dissipation effect on the battery cells. Compared with the liquid cooling method, the heat dissipation effect is obvious.

[0117] 4-5 , there are corresponding surface temperature cloud diagrams of the direct cooling component 510 when the refrigerant outlet of the direct cooling component 510 is in gas-liquid two-phase, and surface temperature cloud diagrams of the area of ​​the direct cooling component 510 where the battery cells are arranged.

[0118] The red temperature shows the highest temperature value, and the blue temperature shows the lowest temperature value. It can be seen from Figures 4-5 that the highest surface temperature of the area where the battery cells are arranged in the direct cooling component 510 is 20.09°C, and the lowest surface temperature is 18.38°C. Therefore, the maximum surface temperature difference of the area where the battery cells are arranged in the direct cooling component 510 is 1.72°C, and the temperature difference varies within the range of 1.72°C. The temperature variation range is small, and the temperature is uniform and stable. Therefore, the cooling and heat dissipation of the battery cells is also uniform and stable.

[0119] The cross section of the cell at a distance of 6 mm from the upper surface of the cell of the energy storage battery 920 is taken as the analysis object. As can be seen from Figures 6-7, the highest temperature of the cell is 26.6°C, the lowest temperature is 25.7°C, and the maximum temperature difference of the cell cross section is 0.9°C. The temperature difference is within the range of 0.9°C, the temperature fluctuation range of the cell is small, and the heat dissipation effect is good.

[0120] From the above analysis, it can be seen that by maintaining the refrigerant at the liquid outlet of the direct cooling component 510 in a gas-liquid two-phase state, the temperature difference at each position on the surface of the direct cooling component 510 can be within a range of 1.72°C and will not exceed 1.72°C. The surface temperature variation range is small and the temperature is uniform, thereby ensuring the uniformity of its cooling of the battery cells.

[0121] At the same time, the temperature difference of the battery cells cooled by the direct cooling component 510 is maintained within 0.9° C., so that the temperature difference range of the entire cross section of the battery cells is small, ensuring the uniformity and stability of the heat dissipation of the battery cells.

[0122] In some embodiments of the present application, the controller is further configured to:

[0123] After detecting that the direct cooling system has been running for a first preset time, the opening of the second throttling component 550 is controlled to achieve control of the dryness of the refrigerant at the liquid outlet of the direct cooling component 510 .

[0124] That is, the refrigerant dryness control function is turned on after the direct cooling system starts the cooling operation for the first preset time.

[0125] The first preset time can be 20S or 30S.

[0126] After the refrigerant dryness control function is turned on, the second throttling component 550 is powered on and reset first.

[0127] Power on reset, after power on the electronic expansion valve behind the direct cooling plate is fully opened to 550 steps.

[0128] Then the controller sends a signal to the second throttle component 550 to control the second throttle component 550 to maintain the initial opening value for a preset time;

[0129] After the refrigerant dryness control function is turned on, the second throttling component 550 enters the control state, otherwise the second throttling component 550 remains in the open state after completing the reset.

[0130] The refrigerant dryness control function is turned on, and the controller first controls the second throttling component 550 to enter the initial opening and maintain it for 60 seconds. The initial opening is fixed at 250 steps.

[0131] The initial opening is maintained for 60 seconds before entering process control.

[0132] Obtain the opening degree of the second throttle component 550, the temperature value of the temperature detection element 560, and the refrigerant saturation temperature of the pressure detection element 570 corresponding to the last adjustment, as well as the temperature value of the temperature detection element 560 and the refrigerant saturation temperature of the pressure detection element 570 corresponding to the current adjustment, and obtain the opening degree value of the second throttle component 550 required for this time through the PID control algorithm;

[0133] The specific control process is as follows:

[0134] Assume: EVB(n)=EVB(n-1)+⊿EVB

[0135] EVB(n): The opening value of the second throttle component 550 that needs to be opened

[0136] EVB(n-1): The second throttle component 550 opened last time

[0137] ⊿EVB=Kp×{⊿Td (n)-⊿Td (n-1)}+Ki×⊿Td (n)

[0138] ⊿Td(n):Tout-Tc

[0139] ⊿Td(n-1): ⊿Td(n) adjusted last time. During the first calculation, ⊿Td(n-1) = ⊿Td(n).

[0140] Tout: The temperature value of the liquid outlet side 522 of the direct cooling component 510 , which is detected and obtained by the temperature detection element 560 .

[0141] Tc: refrigerant saturation temperature corresponding to the pressure value of the direct cooling component 510;

[0142] Kp, Ki: PID control constants

[0143] ⊿ PID control constant of EVB. The constant value is determined according to the debugging results.

[0144] In some embodiments, Kp=0.4, Ki=0.25.

[0145] Through the above process, the opening value required for the second throttling component 550 to be opened can be directly calculated. When the opening value required for the second throttling component 550 to be opened is obtained, the second throttling component 550 can be controlled by the controller to open to the required opening value to ensure that the refrigerant flowing out of the liquid outlet of the direct cooling component 510 is in a gas-liquid two-phase state.

[0146] When specifically controlling the opening of the second throttle component 550 , the controller may control the opening of the second throttle component 550 to a desired opening value within a preset opening range and with a preset number of valve adjustment steps.

[0147] Specifically, the preset opening range of the second throttle component 550 is 110 to 250 steps.

[0148] The preset valve adjustment steps should be within the valve adjustment step range, and the valve adjustment step range is: -30~20 steps.

[0149] In some embodiments of the present application, the controller is configured as follows:

[0150] The opening of the second throttle component 550 is adjusted once every time period T. The time period T can be set according to actual conditions and can be 60S or 70S.

[0151] In some embodiments of the present application, as shown in FIG8 , the direct cooling component 510 includes:

[0152] Upper cover 511;

[0153] A bottom plate 512, wherein the bottom plate 512 and the upper cover 511 are combined to form a refrigerant flow channel;

[0154] The connector 513 is formed with an inlet channel communicating with the inlet of the refrigerant flow path and an outlet channel communicating with the outlet of the refrigerant flow path.

[0155] The refrigerant flowing in from the direct cooling refrigerant pipeline 520 can enter the refrigerant flow path through the inlet channel on the connector 513 to circulate, then evaporate and absorb heat to cool the battery cell, and finally flow out through the outlet channel, flow back into the direct cooling refrigerant pipeline, and flow back into the regenerator 300.

[0156] In some embodiments of the present application, a refrigerant flow channel with a top opening is formed on the bottom plate 512 , and the upper cover 511 is buckled on the bottom plate 512 to block the top opening and form the refrigerant flow channel together with the refrigerant flow channel.

[0157] In some embodiments of the present application, as shown in Figures 9-10 , an air-conditioning compartment 940 is further formed inside the cabinet 900 , and the compressor 100 , the condenser 200 and the regenerator 300 are all arranged in the air-conditioning compartment 940 .

[0158] The cabinet is also provided with a plurality of battery compartments, which are separated by partitions 930 .

[0159] In some embodiments of the present application, the refrigerant flow channel is symmetrically arranged with the left and right width center lines of the direct cooling component 510 as the symmetry axis.

[0160] The refrigerant flow channel is symmetrically divided into two groups of refrigerant channels along the center line of the direct cooling component 510;

[0161] Each group of refrigerant channels includes a side refrigerant channel group 514 and an intermediate refrigerant channel group 515 , and the two groups of intermediate refrigerant channel groups 515 are arranged adjacent to each other.

[0162] When the refrigerant flows in, it flows from the side refrigerant channel groups 514 at both sides, then enters the intermediate refrigerant channel groups 515 of their corresponding groups, flows along the intermediate refrigerant channel groups 515, and finally flows out of the intermediate refrigerant channel groups 515. The two groups of intermediate refrigerant channel groups 515 intersect.

[0163] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0164] The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An energy storage cabinet, characterized in that: Includes: A cabinet body is formed with a battery compartment formed therein, wherein an energy storage battery is arranged in the battery compartment, and the energy storage battery includes a battery cell; Direct cooling system: It is formed by connecting the compressor, condenser, regenerator and direct cooling components through refrigerant pipelines, including: Direct cooling refrigerant pipeline, both ends of which are connected to the regenerator; A direct cooling component, connected to the direct cooling refrigerant pipeline, arranged in the battery compartment, and used to cool the battery cells; a second throttling component connected to the direct cooling refrigerant pipeline and located on the liquid outlet side of the direct cooling component; a pressure detection element connected to the direct cooling refrigerant pipeline and located on the liquid outlet side of the direct cooling component; a temperature detection element connected to the direct cooling refrigerant pipeline and located on the liquid outlet side of the direct cooling component; The controller communicates with at least the second throttling component, the temperature detection element, and the pressure detection element, and is configured as follows: Obtain the temperature and pressure values ​​corresponding to the temperature detection element and the pressure detection element; The refrigerant saturation temperature corresponding to the pressure value is obtained through the refrigerant saturation temperature table pre-stored in it; The opening of the second throttling component is controlled by the PID control algorithm according to the pre-existing internal target temperature difference, the refrigerant saturation temperature and the temperature value, so that the refrigerant at the liquid outlet of the direct cooling component remains in a gas-liquid two-phase state.

2. The energy storage cabinet according to claim 1, characterized in that: The controller is also configured to: After detecting that the second throttle component is powered on, a signal is sent to the second throttle component to control the second throttle component to maintain an initial opening value for a preset time; Obtain the opening degree of the second throttling component, the temperature value of the temperature detection element, and the refrigerant saturation temperature corresponding to the pressure detection element corresponding to the last adjustment, as well as the temperature value of the temperature detection element and the refrigerant saturation temperature corresponding to the pressure detection element corresponding to the current adjustment, and obtain the opening value of the second throttling component that needs to be opened this time through the PID control algorithm; The controller controls the opening of the second throttling component to a desired opening value within a preset opening range and with a preset number of valve adjustment steps.

3. The energy storage cabinet according to claim 1, characterized in that: The controller is further configured to: The operation mode of the energy storage cabinet is obtained before controlling the opening of the second throttling component. When it is obtained that the energy storage cabinet is in the cooling operation mode and the cooling operation time is greater than the first preset time, the opening of the second throttling component is controlled.

4. The energy storage cabinet according to claim 1, characterized in that: The controller is configured as follows: The opening of the second throttling component is adjusted once every time period T.

5. The energy storage cabinet according to claim 1, characterized in that: It also includes: a compressor oil return circuit, which is formed by connecting the compressor, the oil separator, the filter, the oil return capillary tube and the gas-liquid separator through the oil return refrigerant pipe.

6. The energy storage cabinet according to claim 1, characterized in that: Also included are: The compressor unloading and relief circuit is formed by connecting the compressor, unloading solenoid valve, unloading capillary tube and gas-liquid separator through the pressure relief refrigerant pipe.

7. The energy storage cabinet according to claim 1, characterized in that: The direct cooling component comprises: Upper cover; A bottom plate, wherein the bottom plate and the upper cover are combined to form a refrigerant flow channel; A connector is formed with an inlet channel communicating with the inlet of the refrigerant flow channel and an outlet channel communicating with the outlet of the refrigerant flow channel.

8. The energy storage cabinet according to claim 7, characterized in that: A refrigerant flow channel with a top opening is formed on the bottom plate, and the upper cover is buckled on the bottom plate to block the top opening and form the refrigerant flow channel together with the refrigerant flow channel.

9. The energy storage cabinet according to claim 8, characterized in that: The refrigerant flow channel is symmetrically arranged with the left and right width center lines of the direct cooling component as the symmetry axis; The refrigerant flow channel is divided into two groups of refrigerant channels symmetrically along the center line of the direct cooling component; Each group of refrigerant channels includes a side refrigerant channel group and an intermediate refrigerant channel group, and the two groups of intermediate refrigerant channels are arranged adjacent to each other; When the refrigerant flows in, it flows from the side refrigerant channel groups at both sides, then enters the intermediate refrigerant channel groups of its corresponding group, flows along the intermediate refrigerant channel groups, and finally flows out of the intermediate refrigerant channel groups. The outlets of the two intermediate refrigerant channel groups meet.

10. The energy storage cabinet according to claim 1, characterized in that: An air-conditioning compartment is also formed inside the cabinet, and the compressor, condenser and regenerator are all arranged in the air-conditioning compartment.

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