A method for switching series-parallel working state of liquid cooling system of energy storage power station with dehumidification function

Abstract

A method for switching the series-parallel operating state of a liquid cooling system in an energy storage power station with a dehumidification function considers whether to add one or more parallel branches based on actual operational needs. Because all pipe joints utilize multi-way valves with shutoff functions, the parallel operation can be converted to series, or vice versa, simply by controlling the multi-way valves to adjust the opening and closing of certain branches. For example, in a parallel system, three-way valves with shutoff functions are installed at the front and rear ends of the evaporator 5. This closes the parallel branch from the evaporator 5 to the compressor 6 and S-TXV10, and opens the channel from the evaporator 5 to the chiller 4 and EXV3, thus converting the parallel system into a series system.

Description

Technical Field

[0001] The present invention relates to the technical field of cooling of energy storage power stations, and in particular to a method for switching a series-parallel working state of a liquid cooling system of an energy storage power station with a dehumidification function. Background Art

[0002] With the rapid development of energy storage technology, the energy density of energy storage batteries is increasing. However, they still require a certain temperature environment to operate efficiently. Excessively high or low ambient temperatures can severely reduce the battery's service life and pose serious safety risks. Therefore, highly efficient battery thermal management systems have become a key development direction for energy storage technology. Liquid cooling thermal management technology, with its advantages of high heat dissipation efficiency and precise temperature control, has gradually become a mainstream solution. However, liquid cooling units generally lack active dehumidification capabilities. Long-term exposure to environmental influences in battery cabinets can cause condensation, which can easily cause internal wiring short circuits and accelerate corrosion of the cold plate, affecting the normal operation of the batteries.

[0003] To address the dehumidification problem in liquid-cooled units, existing technologies typically place desiccants or absorbent materials inside the battery cabinet. However, this method loses its effectiveness once the absorbent material becomes saturated. Some manufacturers incorporate an additional dehumidifier within the system to perform dehumidification, but this approach not only increases equipment costs but also produces suboptimal dehumidification results.

[0004] Therefore, there is an urgent need to design a liquid cooling system for energy storage power stations with dehumidification function to meet market demand. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the present invention aims to provide a liquid cooling system for an energy storage power station with a dehumidification function, which can optimize the dehumidification effect, improve the temperature and humidity environment of the battery cabinet, and increase its operating efficiency and service life.

[0006] The present invention is implemented by the following technical solution: a series operation method of a liquid cooling system of an energy storage power station with a dehumidification function, comprising a refrigerant pipeline, which is composed of a condenser, an EXV, an evaporator, a chiller, and a compressor connected in sequence to form a loop, and also includes a fan arranged near the condenser and a fan arranged near the evaporator;

[0007] The coolant pipeline consists of a water pump, chiller, PTC, and battery cabinet that are connected in sequence to form a loop;

[0008] Dehumidification pipeline, consisting of battery cabinet and evaporator;

[0009] The chiller includes a refrigerant pipe connection port, which is connected to the refrigerant pipe connection port of the compressor and the evaporator respectively; the chiller also includes a coolant pipe connection port, which is connected to the coolant pipe connection port of the water pump and the PTC respectively;

[0010] The evaporator includes a refrigerant pipe connection port, which is connected to the refrigerant pipe connection port of the chiller and EXV respectively; the evaporator also includes a dehumidification pipe inlet and outlet, which is connected to the dehumidification pipe inlet and outlet of the battery cabinet;

[0011] The battery cabinet includes a coolant pipe connection port, which is connected to the coolant pipe connection ports of the water pump and PTC respectively;

[0012] When it is working, the refrigerant is compressed by the compressor to the condenser for cooling, and then passes through the EXV to the evaporator and chiller for heat exchange;

[0013] It exchanges heat with the high-temperature coolant flowing out of the battery cabinet in the chiller and with the humid air discharged from the battery cabinet in the evaporator.

[0014] The cooled coolant returns to the battery cabinet again;

[0015] The high-temperature and high-humidity air pumped into the battery cabinet by the fan is cooled and dehumidified by the evaporator, and then dried by the fan and sent into the battery cabinet.

[0016] Furthermore, a humidity sensor is provided in the battery cabinet. When the humidity sensor of the battery cabinet detects that the air humidity Rha is less than the set humidity Rhalimit, the fan of the dehumidification module stops running, and there is no dehumidification function at this time; when the humidity sensor of the battery cabinet detects that the humidity Rha is not less than the set humidity Rhalimit, the fan of the dehumidification module is turned on; when the difference between the air humidity Rha and the set humidity Rhalimit increases, the speed of the fan is increased (i.e., the dehumidification efficiency is increased); otherwise, the speed of the fan is reduced; and then it is continued to be judged whether the humidity meets the preset conditions until the humidity meets the preset conditions and the dehumidification module stops working.

[0017] Furthermore, a parallel operation method of a liquid cooling system of an energy storage power station with a dehumidification function is provided.

[0018] The refrigerant pipeline is divided into two branches: the first refrigerant branch consists of a condenser, EXV, chiller, and compressor connected in sequence to form a loop, and also includes a fan installed near the condenser;

[0019] The second refrigerant branch is connected in sequence to form a condenser, S-TXV (thermal expansion valve with solenoid valve, the same below), evaporator, compressor, and also includes a fan installed near the evaporator;

[0020] The coolant pipeline consists of a water pump, chiller, PTC, and battery cabinet that are connected in sequence to form a loop;

[0021] The dehumidification pipeline consists of a battery cabinet and an evaporator. The fan is set in the dehumidification pipeline and blows air towards the surface of the evaporator;

[0022] The chiller includes a refrigerant pipe connection port, which is connected to the refrigerant pipe connection port of the compressor and EXV respectively; the chiller also includes a coolant pipe connection port, which is connected to the coolant pipe connection port of the water pump and battery cabinet respectively;

[0023] The evaporator includes a refrigerant pipeline connection port, which is connected to the refrigerant pipeline connection port of the compressor and S-TXV respectively; the evaporator also includes a dehumidification pipeline inlet and outlet, which is connected to the dehumidification pipeline inlet and outlet of the battery cabinet;

[0024] The battery cabinet includes a coolant pipe connection port, which is connected to the coolant pipe connection ports of the water pump and PTC respectively;

[0025] When it is working, the refrigerant is compressed by the compressor to the condenser and then connected in two parallel routes. One route passes through the EXV to the chiller to exchange heat with the coolant flowing out of the battery cabinet; the other route passes through the S-TXV to the evaporator to exchange heat with the humid air coming in from the battery cabinet.

[0026] The high-temperature coolant flowing out of the battery cabinet goes to the chiller to exchange heat with the refrigerant;

[0027] The cooled coolant returns to the battery cabinet again;

[0028] The high-temperature and high-humidity air coming out of the battery cabinet is cooled and dehumidified by the evaporator, and then dried by the fan and sent back to the battery cabinet.

[0029] Furthermore, a humidity sensor is provided in the battery cabinet. When the humidity sensor of the battery cabinet detects that the humidity Rha is less than the set humidity Rhalimit, the solenoid valve (S-TXV) of the thermal expansion valve does not open, and at this time there is no dehumidification function; when the humidity sensor of the battery cabinet detects that the humidity Rha is not less than the set humidity Rhalimit, the solenoid valve (S-TXV) of the thermal expansion valve opens. When the difference between the air humidity Rha and the set humidity Rhalimit increases, the speed of the fan is increased (i.e., the dehumidification efficiency is increased); otherwise, the speed of the fan is reduced; and then the humidity continues to be judged whether it meets the preset conditions (detecting whether the air humidity Rha is less than the set humidity Rhalimit) until the humidity meets the preset conditions and the dehumidification module stops working.

[0030] Compared with the existing technology, the beneficial effects of the present invention are: providing a working method of a liquid cooling system of an energy storage power station with a dehumidification function, wherein the liquid cooling system box and the battery cabinet box form an air duct isolated from the outside world; an air inlet and an air outlet for wet air are provided on the liquid cooling system, and through logical judgment, when the dehumidification mode needs to be turned on, the fan sucks the wet air in the battery cabinet, dries it through the evaporator, and then sends the dry air back to the battery cabinet.

[0031] The method arranges the dehumidification module on the liquid cooling system in series or parallel, so that the humid air passes through the dehumidification module of the liquid cooling system unit for drying. The method has a simple structure, saves energy consumption, and effectively improves the degree of air drying. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a system schematic diagram of the present invention when operating in parallel working mode;

[0033] Figure 2 It is a parallel operation control flow chart of the present invention;

[0034] Figure 3 This is a system principle diagram of the present invention when operating in series working mode;

[0035] Figure 4 It is a series operation control flow chart of the present invention. Specific implementation methods

[0036] The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific implementation methods. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other unless they conflict.

[0037] The purpose of the present invention is to address the defects of the prior art and provide a working method of a liquid cooling system of an energy storage power station with a dehumidification function. Example

[0038] Parallel working method:

[0039] This embodiment provides a parallel operation mode of a liquid cooling system of an energy storage power station with a dehumidification function. Figure 1 As shown, when it is working, in the cooling working mode of the energy storage power station battery cabinet 9, the refrigerant is compressed by the compressor 6 to the condenser 1, and then connected in two parallel paths. One path passes through EXV3 and then through chiller 4 to exchange heat with the coolant flowing out of the battery cabinet 9; the other path passes through S-TXV10 to enter the dehumidification module evaporator 5 and exchange heat with the wet air entering the battery cabinet 9; the refrigerant with increased temperature and pressure flows back to the compressor 6, completing the refrigeration cycle.

[0040] The high-temperature coolant flowing out of the battery cabinet 9 flows into the chiller 4 to exchange heat with the refrigerant; the cooled coolant returns to the battery cabinet again to cool the battery cabinet 9;

[0041] The high-temperature and high-humidity air coming out of the battery cabinet 9 is cooled and dehumidified by the evaporator 5 , dried by the fan 7 , and then transported back to the battery cabinet 9 .

[0042] Fan 7 is installed in the dehumidified air duct between the battery cabinet 9 and the evaporator 5, blowing air toward the surface of the evaporator 5. This serves to force air circulation, drawing the hot air from the battery cabinet 9 through the duct to the evaporator 5. Furthermore, because the duct forms a loop, fan 7 creates a driving force for forced air circulation within the duct. This allows for forced drawing of hot air from the battery cabinet 9 to the evaporator 5, while also forcing dry, low-temperature air from the evaporator 5 into the battery cabinet 9. On the other hand, the high-temperature air pumped from the battery cabinet 9 is first cooled down by the refrigerant inside the evaporator 5 at the evaporator 5. After the high-humidity air is cooled down, the water content decreases, and water droplets are formed on the surface of the evaporator 5 in the air. Then, under the external force of the fan 7, the water droplets are blown off from the surface of the evaporator 5 before they are completely evaporated and merged into the air. They are collected by the water collection tray at the bottom of the evaporator 5 (the evaporator generally has a water collection tray, but the water droplets on the surface of the ordinary evaporator fall to the water collection tray by gravity, and the speed is relatively slow. The water droplets are easily merged into the air again, resulting in a poor dehumidification effect). Thirdly, the fan 7 blows toward the evaporator 5, accelerating the heat exchange between the refrigerant in the evaporator 5 and the high-temperature and high-humidity air on the surface of the evaporator 5, and accelerating the heat exchange rate between the wet air and the refrigerant (because the refrigerant is forced to run inside the evaporator 5 through the compressor 6, and the wet air is forced to run in the dehumidification pipe through the fan 7, the contact time between the two is limited, and it is necessary to maximize heat exchange within a limited time, so the fan 7 blows toward the surface of the evaporator 5, accelerating the heat exchange rate between the two, enhancing the heat exchange efficiency of the evaporator 5, and improving the dehumidification effect).

[0043] Reference Figure 2 As shown, when the humidity sensor in the battery cabinet 9 detects that the humidity Rha is less than the set humidity Rhalimit, the solenoid valve (S-TXV10) of the thermal expansion valve does not open, and the dehumidification function is disabled. When the humidity sensor in the battery cabinet 9 detects that the humidity Rha is not less than the set humidity Rhalimit, the solenoid valve (S-TXV10) of the thermal expansion valve opens. As the difference between the air humidity Rha and the set humidity Rhalimit increases, the speed of the fan 7 is increased (increasing the dehumidification efficiency); otherwise, the speed of the fan 7 is reduced. The system then continues to determine whether the humidity meets the preset conditions (checking whether the air humidity Rha is less than the set humidity Rhalimit). The dehumidification module stops operating until the temperature and humidity meet the preset conditions.

[0044] In this embodiment, the method of connecting the dehumidification module in parallel with the liquid cooling system has the following advantages:

[0045] 1. Adjustability: The parallel design enables independent adjustment of dehumidification and temperature control, facilitating system commissioning and enabling precise temperature and humidity control. Compared to existing technologies, this system can independently adjust humidity (humid air originates from battery cabinet 9 and is dehumidified by evaporator 5) or temperature (liquid discharged from battery cabinet 9, after heat exchange in chiller 4, returns to battery cabinet 9).

[0046] 2. Safety: Since the dehumidification module operates independently, it will not affect the operation of the liquid cooling system, and the overall safety is better.

[0047] 3. Convenience: It is convenient to inspect and repair the internal refrigeration pipeline. Figure 1 It can be seen that dehumidification of the battery cabinet 9 can be achieved only when the second refrigerant branch is in operation. Therefore, when the coolant pipeline needs to be repaired, it can be conveniently repaired in a parallel system (or a series system can be temporarily converted to a parallel system - the modification method is described below). In this case, the dehumidification of the battery cabinet 9 will not be interrupted due to the maintenance work. Example

[0048] Tandem working method:

[0049] like Figure 3 As shown, when it is working, the refrigerant is compressed by the compressor 6 and sent to the condenser 1 for cooling, and then passes through the EXV3 to the evaporator 5 and chiller 4 for heat exchange; among them, the refrigerant exchanges heat with the high-temperature coolant flowing out of the battery cabinet 9 in the chiller 4, and exchanges heat with the humid air discharged from the battery cabinet 9 in the evaporator 5; the cooled coolant returns to the battery cabinet 9 again; the high-temperature and high-humidity air pumped from the battery cabinet 9 by the fan 7 is cooled and dehumidified by the evaporator 5, and then the air is blown dry by the fan 7 and sent to the battery cabinet 9.

[0050] like Figure 4 When the humidity sensor of the battery cabinet 9 detects that the air humidity Rha is less than the set humidity Rhalimit, the fan 7 of the dehumidification module stops running and the dehumidification function is not available at this time; when the humidity sensor of the battery cabinet 9 detects that the humidity Rha is not less than the set humidity Rhalimit, the fan 7 of the dehumidification module starts; when the difference between the air humidity Rha and the set humidity Rhalimit increases, the speed of the fan 7 is increased (i.e., the dehumidification efficiency is increased); otherwise, the speed of the fan 7 is reduced; then, the humidity continues to be judged whether it meets the preset conditions (detecting whether the air humidity Rha is less than the set humidity Rhalimit) until the humidity meets the preset conditions and the dehumidification module stops working.

[0051] In this embodiment, the method of connecting the dehumidification module in series with the liquid cooling system has the following advantages:

[0052] 1. Simplicity: The series design has a simple structure, and the arrangement order of each structural unit is clear and easy to install;

[0053] 2. Reliability: During the operation of the equipment, the series connection method is easy to maintain and troubleshoot.

[0054] Both of the above working methods can control the temperature inside the battery cabinet 9 while controlling the humidity. And according to actual work needs, it is possible to consider whether to add one or more parallel branches. Because the pipe joints are all connected using multi-way valves with a shut-off function, it is only necessary to control the multi-way valves to adjust the switches of certain branches to transform the parallel connection into a series connection or vice versa. For example, in a parallel system, a three-way valve with a shut-off function is set at the front and rear ends of the evaporator 5, the parallel branch from the evaporator 5 to the compressor 6 and S-TXV10 is closed, and the channel between the evaporator 5 and the chiller 4 and EXV3 is opened, then the parallel system becomes a series system.

[0055] Therefore, this system can easily switch between series and parallel connections by closing or opening multi-way valves, achieving the effect of selecting different systems as needed. For example, in a parallel system, switching to a series system can facilitate the inspection and troubleshooting of certain pipelines.

[0056] When cooling the battery cabinet 9, the evaporator 5 does not perform any cooling function; it merely acts as a pipe in the refrigeration circuit. However, the refrigerant within the evaporator 5 itself does have a cooling effect. Therefore, the high-temperature, high-humidity air within the battery cabinet 9 is introduced into the evaporator 5 to achieve a cooling and dehumidification effect. This solution cleverly places the fan 7 within the dehumidification duct. This not only forces the high-temperature, high-humidity air into the evaporator, but also blows it against the surface of the evaporator 5, accelerating its efficiency (speeding up heat exchange and improving the efficiency of droplet collection on the evaporator 5).

[0057] Since the liquid cooling system has many pipes and the maintenance work is complicated, a series-parallel structure that can be converted to each other is designed to facilitate maintenance by switching pipes. Example

[0058] Compared with Example 1, PT (temperature) sensors are installed at the inlet and outlet of the dehumidification pipeline of the battery cabinet 9 and the inlet and outlet of the coolant pipeline of the battery cabinet 9.

[0059] When the humidity sensor in the battery cabinet 9 detects that the humidity Rha is less than the set humidity Rhalimit, the solenoid valve (S-TXV10) of the thermal expansion valve does not open, and the dehumidification function is disabled. When the humidity sensor in the battery cabinet 9 detects that the humidity Rha is not less than the set humidity Rhalimit, the solenoid valve (S-TXV10) of the thermal expansion valve opens. At this time, the humidity sensor in the battery cabinet 9 detects that the inlet air temperature T of the battery cabinet 9 is less than Ttest_low, and the auxiliary heating device (installed in the return air / inlet air duct of the battery cabinet 9, not shown in the figure) is activated to heat and dry the outlet air. If the humidity sensor detects that the inlet air temperature T of the battery cabinet 9 is greater than Ttest_low and less than Ttest_high, the dehumidification module maintains its original dehumidification state, and the auxiliary heating device does not open until the temperature and humidity meet the preset conditions, at which point the dehumidification module stops operating. Example

[0060] Compared with Example 2, PT (temperature) sensors are installed at the inlet and outlet of the dehumidification pipeline of the battery cabinet 9 and the inlet and outlet of the coolant pipeline of the battery cabinet 9.

[0061] When the humidity sensor of the battery cabinet 9 detects that the air humidity Rha is less than the set humidity Rhalimit, the fan 7 of the dehumidification module stops running, and the dehumidification function is not enabled at this time; when the humidity sensor of the battery cabinet 9 detects that the humidity Rha is not less than the set humidity Rhalimit, the fan 7 of the dehumidification module starts; when the humidity sensor of the battery cabinet 9 detects that the air inlet temperature T of the battery cabinet 9 is less than Ttest_low, the heating device of the auxiliary heating function is turned on to heat and dry the air (not shown in the figure); if the humidity sensor detects that the air inlet temperature T of the battery cabinet 9 is greater than Ttest_low and less than Ttest_high, the dehumidification module maintains the original dehumidification state, and the heating device of the auxiliary heating function is not turned on; until the humidity meets the preset conditions, the dehumidification module stops working.

[0062] The above are only preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for switching a series-parallel operating state of a liquid cooling system of an energy storage power station with a dehumidification function, comprising: The refrigerant pipeline is divided into two branches: the first refrigerant branch is composed of a condenser (1), an EXV (3), a chiller (4), and a compressor (6) which are connected in sequence to form a loop, and also includes a fan arranged near the condenser (1); The second refrigerant branch is composed of a condenser (1), an S-TXV (10), an evaporator (5), and a compressor (6) which are connected in sequence to form a loop, and also includes a fan (7) arranged near the evaporator (5); The coolant line is composed of a water pump, chiller (4), PTC (8), and battery cabinet (9) which are connected in sequence to form a loop; A dehumidification pipeline is composed of a battery cabinet (9) and an evaporator (5), and a fan (7) is arranged in the dehumidification pipeline and blows air toward the surface of the evaporator (5); The chiller (4) includes a refrigerant pipe connection port, which is connected to the refrigerant pipe connection port of the compressor (6) and the EXV (3) respectively; the chiller (4) also includes a coolant pipe connection port, which is connected to the coolant pipe connection port of the water pump and the battery cabinet (9) respectively; The evaporator (5) includes a refrigerant pipeline connection port, which is respectively connected to the refrigerant pipeline connection ports of the compressor (6) and the S-TXV (10); the evaporator (5) also includes a dehumidification pipeline inlet and outlet, which is connected to the dehumidification pipeline inlet and outlet of the battery cabinet (9); The battery cabinet (9) includes a coolant pipe connection port, which is connected to the coolant pipe connection ports of the water pump and the PTC (8) respectively; In the parallel working state, after the refrigerant is compressed by the compressor (6) to the condenser (1), it is connected in two parallel paths. One path passes through the EXV (3) and then goes to the chiller (4) to exchange heat with the coolant flowing out of the battery cabinet (9); the other path passes through the S-TXV (10) and enters the evaporator (5) to exchange heat with the wet air coming in from the battery cabinet. The high-temperature coolant flowing out of the battery cabinet (9) is sent to the chiller (4) to exchange heat with the refrigerant; The cooled coolant returns to the battery cabinet (9); The high-temperature and high-humidity air coming out of the battery cabinet (9) is cooled and dehumidified by the evaporator (5), and then dried by the fan (7) and sent back to the battery cabinet (9); The invention is characterized in that: three-way valves with shut-off functions are provided at the front and rear ends of the evaporator (5), the parallel branch from the evaporator (5) to the compressor (6) and the S-TXV (10) is closed, and the channel from the evaporator (5) to the chiller (4) and the EXV (3) is opened, so that the parallel working state is changed to the series working state; in the series working state, the refrigerant is compressed by the compressor (6) and then flows to the condenser (1) for cooling, and then flows through the EXV (3) to the evaporator (5) and the chiller (4) for heat exchange; wherein, In the chiller (4), heat is exchanged with the high-temperature coolant flowing out of the battery cabinet (9), and in the evaporator (5), heat is exchanged with the moist air discharged from the battery cabinet (9); The cooled coolant returns to the battery cabinet (9); The high-temperature and high-humidity air pumped from the battery cabinet (9) by the fan (7) is cooled and dehumidified by the evaporator (5) and then dried by the fan (7) and sent back to the battery cabinet (9).

2. The method for switching the series-parallel working state of the liquid cooling system of an energy storage power station with a dehumidification function according to claim 1, characterized in that: In the series working state, a humidity sensor is provided in the battery cabinet (9). When the humidity sensor of the battery cabinet (9) detects that the air humidity Rha is less than the set humidity Rhalimit, the fan (7) of the dehumidification module stops running, and the dehumidification function is not provided at this time. When the humidity sensor of the battery cabinet (9) detects that the humidity Rha is not less than the set humidity Rhalimit, the fan (7) of the dehumidification module is turned on. When the difference between the air humidity Rha and the set humidity Rhalimit increases, the rotation speed of the fan (7) is increased; otherwise, the rotation speed of the fan (7) is reduced. Then, it is continuously judged whether the humidity meets the preset condition, until the humidity meets the preset condition, and the dehumidification module stops working.

3. The method for switching the series-parallel working state of the liquid cooling system of the energy storage power station with dehumidification function according to claim 1, characterized in that: In the parallel working state, a humidity sensor is provided in the battery cabinet (9). When the humidity sensor of the battery cabinet (9) detects that the humidity Rha is less than the set humidity Rhalimit, the S-TXV (10) is not turned on, and the dehumidification function is not provided at this time. When the humidity sensor of the battery cabinet (9) detects that the humidity Rha is not less than the set humidity Rhalimit, the S-TXV (10) is turned on. When the difference between the air humidity Rha and the set humidity Rhalimit increases, the rotation speed of the fan (7) is increased; otherwise, the rotation speed of the fan (7) is reduced. Then, it is continuously judged whether the humidity meets the preset condition until the humidity meets the preset condition and the dehumidification module stops working.

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