Ultra-low voltage ratio operation energy-saving control method for energy storage battery liquid cooling unit

Abstract

The invention provides an ultra-low-pressure-ratio operation energy-saving control method for an energy storage battery liquid cooling unit, which comprises the following steps of: calculating a return air pressure saturation temperature target value based on a working parameter, determining a control parameter of an electronic expansion valve based on a relationship between the return air pressure saturation temperature value and the return air pressure saturation temperature value, and controlling the electronic expansion valve based on the working parameter. Calculating to obtain an exhaust pressure saturation temperature target value, and determining a control parameter of the fan based on the relation between the exhaust pressure saturation temperature value and the exhaust pressure saturation temperature value, so that the return air pressure is always operated at a reasonable high value; the exhaust pressure is controlled through the rotating speed of the draught fan, the target value of the exhaust pressure is obtained through real-time calculation of the environment temperature, the compressor pressure ratio and the air return pressure, the exhaust pressure always runs within the reasonable range, and in the low-temperature season, ultra-low-pressure-ratio running of the system can be achieved, the power consumption of the compressor is greatly reduced, the energy efficiency is improved, and energy conservation and emission reduction are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of unit energy saving, and in particular to an ultra-low pressure ratio operation energy saving control method for an energy storage battery liquid cooling unit. Background Art

[0002] At present, the energy structure is undergoing rapid changes. As a form of new energy, energy storage batteries are currently in a period of rapid development in applications, such as household storage, industrial and commercial storage, energy storage power stations, etc. Liquid cooling units, as a common equipment for thermal management of energy storage batteries, are also in a period of rapid development. Figure 2 It is shown that the structure distribution of the energy storage battery liquid cooling unit system is mainly composed of a compressor, a low-pressure sensor, a return air temperature sensor, a return liquid temperature sensor, a liquid supply temperature sensor, a medium heat exchanger, an electronic expansion valve, an ambient temperature sensor, an outer heat exchanger, a fan, a high-pressure sensor, and an exhaust temperature sensor. It uses vapor compression refrigeration to generate coolant, which is supplied to the energy storage battery cooling system to take away heat and maintain a reasonable temperature environment required for the battery to work.

[0003] Due to the heat dissipation requirements of energy storage batteries, liquid cooling units generally operate for cooling throughout the year; in low temperature seasons, there are natural cold sources outdoors, but in order to ensure the reliability of the compressor, current liquid cooling units still control the compressor exhaust pressure to be maintained at a higher value during low temperature seasons, which makes the compressor have a large pressure ratio, high power consumption, low energy efficiency, and increased operating costs; the traditional solution controls the fan speed according to the exhaust pressure. In order to ensure the reliability of the compressor operation, the exhaust pressure is always maintained at a high value. In low temperature environments, the exhaust pressure is increased by reducing the fan speed or turning it off, which makes the compressor have a large pressure ratio, high power consumption, and low energy efficiency. Summary of the invention

[0004] The present invention provides an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit, which is used to solve the problems raised in the background technology.

[0005] An ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit, comprising:

[0006] S1: Obtain the structural distribution of the energy storage battery liquid cooling unit system, and collect the working parameters of the battery liquid cooling unit system from the structural distribution;

[0007] S2: Based on the working parameters, a return air pressure saturation temperature target value is calculated, and based on the relationship between the return air pressure saturation temperature value and the return air pressure saturation temperature value, a control parameter for the electronic expansion valve is determined;

[0008] S3: Based on the working parameters, the exhaust pressure saturation temperature target value is calculated, and based on the relationship between the exhaust pressure saturation temperature value and the exhaust pressure saturation temperature value, the control parameters for the fan are determined.

[0009] Preferably, in S1, the structural distribution of the energy storage battery liquid cooling unit system is obtained, including a compressor, a liquid supply pipe is connected through the compressor, the other end of the liquid supply pipe is connected through the outer heat exchanger, an exhaust temperature sensor and a high-pressure sensor are also provided on the liquid supply pipe, a fan and an ambient temperature sensor are provided on the outer heat exchanger, a connecting pipe is also connected through the outer heat exchanger, the other end of the connecting pipe is connected through the medium heat exchanger, an electronic expansion valve is provided on the connecting pipe, a liquid return pipe is connected through the medium heat exchanger, the other end of the liquid return pipe is connected through the compressor, a low-pressure sensor and a return air temperature sensor are provided on the liquid return pipe, and a liquid return temperature sensor and a liquid supply temperature sensor are also provided on the medium heat exchanger.

[0010] Preferably, in S1, the operating parameters of the battery liquid cooling system are collected from the structural distribution, including:

[0011] The return air pressure of the energy storage battery liquid cooling unit system is collected from the low pressure sensor, the exhaust pressure of the energy storage battery liquid cooling unit system is collected from the high pressure sensor, the return liquid temperature is collected from the return liquid temperature sensor, the supply liquid temperature is collected from the supply liquid temperature sensor, the return air pressure temperature value is collected from the return air temperature sensor, the exhaust temperature value is collected from the exhaust temperature sensor, and the ambient temperature value is collected from the ambient temperature sensor.

[0012] Preferably, in S2, based on the working parameters, the target value of the return air pressure saturation temperature is calculated, including:

[0013] Based on the working parameters, the return air pressure saturation temperature target value is calculated according to the following formula;

[0014] Tes=To-x*△t1 / b

[0015] K=Pd-Tc

[0016] Among them, Tes represents the return gas pressure saturation temperature target value, To represents the supply liquid temperature value, and K represents the exhaust gas superheat;

[0017] When the compressor is turned off, x returns to the default value. After the compressor is turned on, it is corrected in real time according to the exhaust superheat, specifically:

[0018] When the exhaust superheat is greater than c, x is reduced by 1 from the current real-time value in each adjustment cycle, and the corrected Tes value is generally not higher than the Tes value calculated according to the default value of x plus 4°C;

[0019] When c≥exhaust superheat≥c-△t2, x keeps the current real-time value unchanged;

[0020] When c-△t2>exhaust superheat, x adds 1 to the current real-time value in each adjustment cycle, and the corrected Tes value is generally not lower than the Tes value calculated according to the default value of x minus 4℃.

[0021] Preferably, in S2, based on the relationship between the return air pressure saturation temperature value and the return air pressure saturation temperature value, determining the control parameters of the electronic expansion valve includes:

[0022] When the return gas pressure saturation temperature value is greater than the sum of the return gas pressure saturation temperature value and the return temperature difference, the electronic expansion valve is controlled to be closed;

[0023] When the return air pressure saturation temperature value is equal to the sum of the return air pressure saturation temperature value and the return temperature difference, the current opening of the electronic expansion valve is kept unchanged;

[0024] When the return gas pressure saturation temperature value is less than the sum of the return gas pressure saturation temperature value and the return temperature difference, the electronic expansion valve is controlled to open wider.

[0025] Preferably, in S3, based on the working parameters, the exhaust pressure saturation temperature target value is calculated, including:

[0026] Based on the working parameters, the exhaust pressure saturation temperature target value is calculated according to the following formula;

[0027] Tcs=max(T1+△t3、y*Pes)

[0028] Wherein, Tcs represents the exhaust pressure saturation temperature target value, T1 represents the ambient temperature value, Pes represents the return air pressure saturation temperature target value, and the y value is determined according to the minimum pressure ratio allowed by the compressor specification, which is generally 1.1 to 1.3;

[0029] When compressor 1 is turned off, the y value returns to the default value. After the compressor is turned on, the y value is corrected according to the return air pressure saturation temperature Te:

[0030] When Te<Tes-a, and the opening of the electronic expansion valve exceeds 70% of its maximum opening, the y value is increased by 0.1 on the basis of the current real-time value in each adjustment cycle. The corrected y value should always be limited to the maximum correction value on the basis of the default value. Generally, the corrected y value does not exceed 1.5-1.8;

[0031] When Tes≥Te≥Tes-a, the y value maintains the current real-time value;

[0032] When Te>Tes, the y value is reduced by 0.1 based on the current real-time value in each adjustment cycle. The corrected y value is always not less than the default value. Generally, the corrected y value is ≥1.1.

[0033] Preferably, in S3, based on the exhaust pressure saturation temperature value and the relationship between the exhaust pressure saturation temperature value, determining the control parameters of the fan includes:

[0034] When the exhaust pressure saturation temperature value is greater than the sum of the exhaust pressure saturation temperature value and the return temperature, controlling the fan to increase the speed;

[0035] When the exhaust pressure saturation temperature value is equal to the sum of the exhaust pressure saturation temperature value and the return temperature, the speed of the fan is controlled to remain unchanged;

[0036] When the exhaust pressure saturation temperature value is less than the sum of the exhaust pressure saturation temperature value and the return temperature, the fan is controlled to reduce the rotation speed.

[0037] Preferably, it also includes:

[0038] Obtaining the operating pressure ratio of the compressor under the operation of the control parameters of the electronic expansion valve and the control parameters of the fan;

[0039] Based on the relationship between the operating pressure ratio and the preset operating pressure ratio, the control parameters are fine-tuned.

[0040] Preferably, the fine-tuning of the control parameter based on the relationship between the operating pressure ratio and the preset operating pressure ratio includes:

[0041] When the operating pressure ratio is less than or equal to the preset operating pressure ratio, the control parameter is not adjusted;

[0042] When the operating pressure ratio is greater than the preset operating pressure ratio, the control parameter to be adjusted when the operating pressure ratio is greater than the preset operating pressure ratio is obtained, and the control parameter to be adjusted is fine-tuned based on the operating pressure ratio-parameter curve diagram.

[0043] Preferably, based on the operating pressure ratio-parameter curve diagram, fine-tuning the control parameter to be adjusted includes:

[0044] Based on the real-time collected real-time working parameters and real-time control parameters of the energy storage battery liquid cooling unit system, and by monitoring the operating pressure ratio under the real-time working parameters and real-time control parameters, an operating pressure ratio-parameter curve diagram is established;

[0045] Obtaining a maximum operating pressure ratio and a first parameter corresponding thereto, and a minimum operating pressure ratio and a second parameter corresponding thereto from the operating pressure ratio-parameter curve diagram, determining an optimal parameter relationship between a first operating parameter and a first control parameter based on the first parameter, and determining a worst parameter relationship between a second operating parameter and a second control parameter based on the second parameter;

[0046] Determine a first operating pressure ratio difference and a second operating pressure ratio difference between the operating pressure ratio and a maximum operating pressure ratio and a minimum operating pressure ratio, respectively;

[0047] Based on the first operating pressure difference ratio, determining a control parameter adjustment range, based on the worst parameter relationship and in combination with the working parameters of the operating pressure ratio, determining a control parameter adjustment weight, and based on the control parameter adjustment range and the control parameter adjustment weight, determining fine-tuning data of the control parameter to be adjusted;

[0048] Based on the second operating pressure difference ratio and the optimal parameter relationship, the fine-tuning data is verified and corrected to determine whether the parameter relationship between the control parameter adjusted according to the fine-tuning data and the working parameter of the operating pressure ratio is within a preset range from the optimal parameter relationship;

[0049] If yes, fine-tune the control parameter to be adjusted according to the fine-tuning data;

[0050] Otherwise, the fine-tuning data is corrected based on the second operating pressure difference ratio.

[0051] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0052] By acquiring the structural distribution of the energy storage battery liquid cooling unit system, and collecting the working parameters of the battery liquid cooling unit system from the structural distribution, based on the working parameters, the return air pressure saturation temperature target value is calculated, and based on the relationship between the return air pressure saturation temperature value and the return air pressure saturation temperature value, the control parameters of the electronic expansion valve are determined, and based on the working parameters, the exhaust pressure saturation temperature target value is calculated, and based on the relationship between the exhaust pressure saturation temperature value and the exhaust pressure saturation temperature value, the control parameters of the fan are determined, so that the return air pressure always runs at a reasonable high value; the exhaust pressure is controlled by the fan speed, and the exhaust pressure target value is calculated in real time from the ambient temperature, the compressor pressure ratio, and the return air pressure, so that the exhaust pressure always runs within a reasonable range. In the low temperature season, the system can achieve ultra-low pressure ratio operation, which greatly reduces the power consumption of the compressor, improves energy efficiency, and achieves energy conservation and emission reduction.

[0053] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures specifically pointed out in this application document.

[0054] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0056] Figure 1 It is a flow chart of an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit in an embodiment of the present invention;

[0057] Figure 2 This is a structural distribution diagram of the energy storage battery liquid cooling unit system in an embodiment of the present invention;

[0058] Figure 3 The flowchart of fine-tuning control parameters in an embodiment of the present invention. DETAILED DESCRIPTION

[0059] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0060] Embodiment 1:

[0061] Based on Example 1, the present invention provides an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit, such as Figure 1 As shown, including:

[0062] S1: Obtain the structural distribution of the energy storage battery liquid cooling unit system, and collect the working parameters of the battery liquid cooling unit system from the structural distribution;

[0063] S2: Based on the working parameters, the return air pressure saturation temperature target value is calculated, and based on the relationship between the return air pressure saturation temperature value and the return air pressure saturation temperature value, the control parameters of the electronic expansion valve 7 are determined;

[0064] S3: Based on the working parameters, the exhaust pressure saturation temperature target value is calculated, and based on the relationship between the exhaust pressure saturation temperature value and the exhaust pressure saturation temperature value, the control parameters for the fan 10 are determined.

[0065] In this embodiment, the return air pressure saturation temperature value is obtained by converting the return air pressure value.

[0066] In this embodiment, the exhaust pressure saturation temperature value is obtained by converting the exhaust pressure value.

[0067] In this embodiment, the electronic expansion valve controls the return air pressure, the fan speed controls the exhaust pressure, the control parameter of the electronic expansion valve 7 is specifically the control of the opening of the electronic expansion valve, and the control parameter of the fan 10 is specifically the control of the fan speed.

[0068] In this embodiment, the present invention proposes an energy-saving control method for ultra-low pressure ratio operation of an energy storage liquid cooling unit, in which the return air pressure is controlled by an electronic expansion valve, and the return air pressure target value is calculated in real time by the liquid supply temperature and the exhaust superheat, so that the return air pressure is always kept at a reasonable high value; the exhaust pressure is controlled by the fan speed, and the exhaust pressure target value is calculated in real time by the ambient temperature, the compressor pressure ratio, and the return air pressure, so that the exhaust pressure is always kept within a reasonable range. In low temperature seasons, the system can achieve ultra-low pressure ratio operation, greatly reduce the power consumption of the compressor, improve energy efficiency, and achieve energy conservation and emission reduction.

[0069] In this embodiment, the operating parameters of the battery liquid cooling system include detection parameters of various sensors.

[0070] The beneficial effects of the above design scheme are as follows: by obtaining the structural distribution of the energy storage battery liquid cooling unit system, and collecting the working parameters of the battery liquid cooling unit system from the structural distribution, based on the working parameters, the return air pressure saturation temperature target value is calculated, and based on the relationship between the return air pressure saturation temperature value and the return air pressure saturation temperature value, the control parameters of the electronic expansion valve 7 are determined, based on the working parameters, the exhaust pressure saturation temperature target value is calculated, and based on the relationship between the exhaust pressure saturation temperature value and the exhaust pressure saturation temperature value, the control parameters of the fan 10 are determined, so that the return air pressure always runs at a reasonable high value; the exhaust pressure is controlled by the fan speed, and the exhaust pressure target value is calculated in real time from the ambient temperature, the compressor pressure ratio, and the return air pressure, so that the exhaust pressure always runs within a reasonable range. In the low temperature season, the system can achieve ultra-low pressure ratio operation, which greatly reduces the power consumption of the compressor, improves energy efficiency, and achieves energy conservation and emission reduction.

[0071] Embodiment 2:

[0072] Based on Example 1, the present invention provides an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit, such as Figure 2As shown, in S1, the structural distribution of the energy storage battery liquid cooling unit system is obtained, including a compressor 1, a liquid supply pipe is connected to the compressor 1, and the other end of the liquid supply pipe is connected to the outer heat exchanger 9, and an exhaust temperature sensor 12 and a high-pressure sensor 11 are also provided on the liquid supply pipe, and a fan 10 and an ambient temperature sensor 8 are provided on the outer heat exchanger 9. A connecting pipe is also connected to the outer heat exchanger 9, and the other end of the connecting pipe is connected to the medium heat exchanger 6. An electronic expansion valve 7 is provided on the connecting pipe, and a liquid return pipe is connected to the medium heat exchanger 6, and the other end of the liquid return pipe is connected to the compressor 1, and a low-pressure sensor 2 and a return air temperature sensor 3 are provided on the liquid return pipe. A liquid return temperature sensor 4 and a liquid supply temperature sensor 5 are also provided on the medium heat exchanger 6.

[0073] The beneficial effects of the above design scheme are: providing a structural distribution of the energy storage battery liquid cooling unit system, and providing a structural basis for ultra-low pressure ratio operation energy-saving control.

[0074] Embodiment 3:

[0075] Based on Example 2, the embodiment of the present invention provides an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit. In S1, the operating parameters of the battery liquid cooling unit system are collected from the structural distribution, including:

[0076] The return air pressure of the energy storage battery liquid cooling unit system is collected from the low pressure sensor 2, the exhaust pressure of the energy storage battery liquid cooling unit system is collected from the high pressure sensor 11, the return liquid temperature is collected from the return liquid temperature sensor 4, the supply liquid temperature is collected from the supply liquid temperature sensor 5, the return air pressure temperature value is collected from the return air temperature sensor 3, the exhaust temperature value is collected from the exhaust temperature sensor 12, and the ambient temperature value is collected from the ambient temperature sensor 8.

[0077] The beneficial effect of the above design scheme is: the working parameters are obtained by collecting the parameters of each sensor, thereby providing a parameter basis for energy-saving control of ultra-low pressure ratio operation.

[0078] Embodiment 4:

[0079] Based on Example 1, the embodiment of the present invention provides an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit. In S2, based on the working parameters, the return air pressure saturation temperature target value is calculated, including:

[0080] Based on the working parameters, the return air pressure saturation temperature target value is calculated according to the following formula;

[0081] Tes=To-x*△t1 / b

[0082] K=Pd-Tc

[0083] Among them, Tes represents the return gas pressure saturation temperature target value, To represents the supply liquid temperature value, and K represents the exhaust gas superheat;

[0084] When compressor 1 is turned off, x returns to the default value. After compressor 1 is turned on, it is corrected in real time according to the exhaust superheat, specifically:

[0085] When the exhaust superheat is greater than c, x is reduced by 1 from the current real-time value in each adjustment cycle, and the corrected Tes value is generally not higher than the Tes value calculated according to the default value of x plus 4°C;

[0086] When c≥exhaust superheat≥c-△t2, x keeps the current real-time value unchanged;

[0087] When c-△t2>exhaust superheat, x adds 1 to the current real-time value in each adjustment cycle, and the corrected Tes value is generally not lower than the Tes value calculated according to the default value of x minus 4℃.

[0088] In this embodiment, △t1 is generally 2 to 5, b is generally 10, and the default value of x is generally equal to b; the values ​​of c and △t2 must meet the reliability requirements in the compressor specification, and at the same time, it is not advisable to leave too large a margin, so as to maintain the return air pressure saturation temperature at a high value as much as possible.

[0089] The beneficial effects of the above design scheme are: through the above control method, the return air pressure saturation temperature value is always maintained at a reasonable high value, which can reduce the output speed of the compressor and reduce power consumption. The return air pressure saturation temperature target value is calculated according to the working parameters of the energy storage battery liquid cooling unit system, providing a numerical basis for energy-saving control of ultra-low pressure ratio operation.

[0090] Embodiment 5:

[0091] Based on Example 1, the embodiment of the present invention provides an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit. In S2, based on the relationship between the return air pressure saturation temperature value and the return air pressure saturation temperature value, the control parameters of the electronic expansion valve 7 are determined, including:

[0092] When the return air pressure saturation temperature value is greater than the sum of the return air pressure saturation temperature value and the return temperature difference, the electronic expansion valve 7 is controlled to be closed;

[0093] When the return air pressure saturation temperature value is equal to the sum of the return air pressure saturation temperature value and the return temperature difference, the current opening of the electronic expansion valve 7 is kept unchanged;

[0094] When the return air pressure saturation temperature value is less than the sum of the return air pressure saturation temperature value and the return temperature difference, the electronic expansion valve 7 is controlled to be opened wide.

[0095] The beneficial effect of the above design scheme is: through the above control method, the return air pressure saturation temperature value is always maintained at a reasonable high value, which can reduce the output speed of the compressor, reduce power consumption, and ensure ultra-low pressure ratio operation from the return air pressure aspect.

[0096] Embodiment 6:

[0097] Based on Example 1, the embodiment of the present invention provides an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit. In S3, based on the working parameters, the exhaust pressure saturation temperature target value is calculated, including:

[0098] Based on the working parameters, the exhaust pressure saturation temperature target value is calculated according to the following formula;

[0099] Tcs=max(T1+△t3、y*Pes)

[0100] Wherein, Tcs represents the exhaust pressure saturation temperature target value, T1 represents the ambient temperature value, Pes represents the return air pressure saturation temperature target value, and the y value is determined according to the minimum pressure ratio allowed by the compressor specification, which is generally 1.1 to 1.3;

[0101] When compressor 1 is turned off, the y value returns to the default value. After compressor 1 is turned on, the y value is corrected according to the return air pressure saturation temperature Te:

[0102] When Te<Tes-a, and the opening of the electronic expansion valve exceeds 70% of its maximum opening, the y value is increased by 0.1 on the basis of the current real-time value in each adjustment cycle. The corrected y value should always be limited to the maximum correction value on the basis of the default value. Generally, the corrected y value does not exceed 1.5-1.8;

[0103] When Tes≥Te≥Tes-a, the y value maintains the current real-time value;

[0104] When Te>Tes, the y value is reduced by 0.1 based on the current real-time value in each adjustment cycle. The corrected y value is always not less than the default value. Generally, the corrected y value is ≥1.1.

[0105] In this embodiment, Δt3 is generally 5 to 10, and a is generally 0 to 2.

[0106] The beneficial effect of the above design scheme is: by calculating the exhaust pressure saturation temperature target value according to the working parameters of the energy storage battery liquid cooling unit system, a numerical basis is provided for energy-saving control of ultra-low pressure ratio operation.

[0107] Embodiment 7:

[0108] Based on Example 1, the embodiment of the present invention provides an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit. In S3, based on the relationship between the exhaust pressure saturation temperature value and the exhaust pressure saturation temperature value, the control parameters of the fan 10 are determined, including:

[0109] When the exhaust pressure saturation temperature value is greater than the sum of the exhaust pressure saturation temperature value and the return temperature, the fan 10 is controlled to increase the rotation speed;

[0110] When the exhaust pressure saturation temperature value is equal to the sum of the exhaust pressure saturation temperature value and the return temperature, the speed of the fan 10 is controlled to remain unchanged;

[0111] When the exhaust pressure saturation temperature value is less than the sum of the exhaust pressure saturation temperature value and the return temperature, the fan 10 is controlled to reduce the rotation speed.

[0112] The beneficial effect of the above design scheme is: through the above control method, the exhaust pressure is always operated within a reasonable range, especially in low temperature seasons, ultra-low pressure ratio operation can be achieved, the compressor power consumption is greatly reduced, the operating energy efficiency is improved, and the ultra-low pressure ratio operation is guaranteed from the exhaust pressure aspect.

[0113] Embodiment 8:

[0114] Based on Example 1, the present invention provides an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit, such as Figure 3 As shown, it also includes:

[0115] Obtaining the operating pressure ratio of the compressor 1 under the operation of the control parameters of the electronic expansion valve 7 and the control parameters of the fan 10;

[0116] Based on the relationship between the operating pressure ratio and the preset operating pressure ratio, the control parameters are fine-tuned.

[0117] The beneficial effect of the above design scheme is: by obtaining the operating pressure ratio of the compressor 1 under the operation of the control parameters of the electronic expansion valve 7 and the control parameters of the fan 10, based on the relationship between the operating pressure ratio and the preset operating pressure ratio, the control parameters are fine-tuned to achieve ultra-low pressure ratio operation of the energy storage battery liquid cooling unit.

[0118] Embodiment 9:

[0119] Based on Example 8, an embodiment of the present invention provides an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit, wherein the control parameters are fine-tuned based on the relationship between the operating pressure ratio and the preset operating pressure ratio, including:

[0120] When the operating pressure ratio is less than or equal to the preset operating pressure ratio, the control parameter is not adjusted;

[0121] When the operating pressure ratio is greater than the preset operating pressure ratio, the control parameter to be adjusted when the operating pressure ratio is greater than the preset operating pressure ratio is obtained, and the control parameter to be adjusted is fine-tuned based on the operating pressure ratio-parameter curve diagram.

[0122] In this embodiment, the operating pressure ratio-parameter curve diagram is obtained according to the operating conditions of the energy storage battery liquid cooling unit.

[0123] The beneficial effect of the above design scheme is: when the operating pressure ratio is greater than the preset operating pressure ratio, the control parameter to be adjusted is obtained, and based on the operating pressure ratio-parameter curve diagram, the control parameter to be adjusted is fine-tuned to ensure that the energy storage battery liquid cooling unit system always maintains ultra-low pressure ratio operation and reduces energy consumption.

[0124] Embodiment 10:

[0125] Based on Example 9, the embodiment of the present invention provides an ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit, and fine-tuning the control parameter to be adjusted based on the operating pressure ratio-parameter curve diagram, including:

[0126] Based on the real-time collected real-time working parameters and real-time control parameters of the energy storage battery liquid cooling unit system, and by monitoring the operating pressure ratio under the real-time working parameters and real-time control parameters, an operating pressure ratio-parameter curve diagram is established;

[0127] Obtaining a maximum operating pressure ratio and a first parameter corresponding thereto, and a minimum operating pressure ratio and a second parameter corresponding thereto from the operating pressure ratio-parameter curve diagram, determining an optimal parameter relationship between a first operating parameter and a first control parameter based on the first parameter, and determining a worst parameter relationship between a second operating parameter and a second control parameter based on the second parameter;

[0128] Determine a first operating pressure ratio difference and a second operating pressure ratio difference between the operating pressure ratio and a maximum operating pressure ratio and a minimum operating pressure ratio, respectively;

[0129] Based on the first operating pressure difference ratio, determining a control parameter adjustment range, based on the worst parameter relationship and in combination with the working parameters of the operating pressure ratio, determining a control parameter adjustment weight, and based on the control parameter adjustment range and the control parameter adjustment weight, determining fine-tuning data of the control parameter to be adjusted;

[0130] Based on the second operating pressure difference ratio and the optimal parameter relationship, the fine-tuning data is verified and corrected to determine whether the parameter relationship between the control parameter adjusted according to the fine-tuning data and the working parameter of the operating pressure ratio is within a preset range from the optimal parameter relationship;

[0131] If yes, fine-tune the control parameter to be adjusted according to the fine-tuning data;

[0132] Otherwise, the fine-tuning data is corrected based on the second operating pressure difference ratio.

[0133] In this embodiment, the operating pressure ratio-parameter curve diagram is a relationship diagram among the operating pressure ratio, the working parameters and the control parameters.

[0134] In this embodiment, the larger the first operating pressure difference ratio is, the smaller the corresponding parameter adjustment range is.

[0135] In this embodiment, the greater the difference between the operating parameter of the operating pressure ratio and the operating parameter in the worst parameter relationship, the greater the corresponding parameter adjustment weight.

[0136] In this embodiment, the fine-tuning data of the control parameters to be adjusted are the adjustment of the opening of the electronic expansion valve 7 and the adjustment of the rotation speed of the fan 10 .

[0137] In this embodiment, the way of correcting the fine-tuning data based on the second operating pressure difference ratio is opposite to the way of adjusting based on the first operating pressure difference ratio.

[0138] The beneficial effect of the above design scheme is: by obtaining the highest operating pressure ratio and its corresponding first parameter, as well as the lowest operating pressure ratio and its corresponding second parameter from the operating pressure ratio-parameter curve diagram, determining the optimal parameter relationship between the first working parameter and the first control parameter based on the first parameter, and determining the worst parameter relationship between the second working parameter and the second control parameter based on the second parameter, determining the first operating pressure ratio difference and the second operating pressure ratio difference between the operating pressure ratio and the highest operating pressure and the lowest operating pressure ratio respectively, analyzing the operating pressure ratio to be adjusted according to the first operating pressure ratio difference and the second operating pressure ratio difference, the optimal parameter relationship and the worst parameter relationship, determining the adjustment parameters, ensuring that the real-time operating pressure ratio is always guaranteed to be within the preset range, greatly reducing the power consumption of the compressor, and improving the operating energy efficiency.

[0139] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention belong to the scope of this application document and its equivalent technology, the present invention is also intended to include these changes and variations.

Claims

1. An ultra-low pressure ratio operation energy-saving control method for an energy storage battery liquid cooling unit, characterized in that: include: S1: Obtain the structural distribution of the energy storage battery liquid cooling unit system, and collect the working parameters of the battery liquid cooling unit system from the structural distribution; S2: Based on the working parameters, a return air pressure saturation temperature target value is calculated, and based on the relationship between the return air pressure saturation temperature value and the return air pressure saturation temperature value, a control parameter for the electronic expansion valve (7) is determined; S3: Based on the working parameters, the exhaust pressure saturation temperature target value is calculated, and based on the exhaust pressure saturation temperature value and the relationship between the exhaust pressure saturation temperature value, the control parameters for the fan (10) are determined.

2. The ultra-low pressure ratio operation energy-saving control method of the energy storage battery liquid cooling unit according to claim 1 is characterized in that: In the above S1, the structural distribution of the energy storage battery liquid cooling unit system is obtained, including a compressor (1), a liquid supply pipe is connected to the compressor (1), the other end of the liquid supply pipe is connected to the outer heat exchanger (9), an exhaust temperature sensor (12) and a high pressure sensor (11) are also provided on the liquid supply pipe, a fan (10) and an ambient temperature sensor (8) are provided on the outer heat exchanger (9), a connecting pipe is connected to the outer heat exchanger (9), the other end of the connecting pipe is connected to the medium heat exchanger (6), an electronic expansion valve (7) is provided on the connecting pipe, a liquid return pipe is connected to the medium heat exchanger (6), the other end of the liquid return pipe is connected to the compressor (1), a low pressure sensor (2) and a return air temperature sensor (3) are provided on the liquid return pipe, and a liquid return temperature sensor (4) and a liquid supply temperature sensor (5) are also provided on the medium heat exchanger (6).

3. The ultra-low pressure ratio operation energy-saving control method of the energy storage battery liquid cooling unit according to claim 2 is characterized in that: In S1, the operating parameters of the battery liquid cooling system are collected from the structural distribution, including: The return air pressure of the energy storage battery liquid cooling system is acquired from the low pressure sensor (2), the exhaust pressure of the energy storage battery liquid cooling system is acquired from the high pressure sensor (11), the return liquid temperature is acquired from the return liquid temperature sensor (4), the supply liquid temperature is acquired from the supply liquid temperature sensor (5), the return air pressure temperature value is acquired from the return air temperature sensor (3), the exhaust temperature value is acquired from the exhaust temperature sensor (12), and the ambient temperature value is acquired from the ambient temperature sensor (8).

4. The ultra-low pressure ratio operation energy-saving control method of the energy storage battery liquid cooling unit according to claim 1 is characterized in that: In S2, based on the working parameters, the target value of the return air pressure saturation temperature is calculated, including: Based on the working parameters, the return air pressure saturation temperature target value is calculated according to the following formula; Tes=To-x*△t1 / b K=Pd-Tc Among them, Tes represents the target value of the return gas pressure saturation temperature, To represents the supply liquid temperature value, K represents the exhaust superheat, △t1 is generally 2 to 5, b is generally 10, Pd represents the exhaust temperature, and Tc represents the exhaust pressure corresponding to the saturation temperature; When the compressor (1) is turned off, x returns to the default value. After the compressor (1) is turned on, it is corrected in real time according to the exhaust superheat, specifically: When the exhaust superheat is greater than c, x is reduced by 1 from the current real-time value in each adjustment cycle, and the corrected Tes value is generally not higher than the Tes value calculated according to the default value of x plus 4°C; When c≥exhaust superheat≥c-△t2, x keeps the current real-time value unchanged; When c-△t2>exhaust superheat, x adds 1 to the current real-time value in each adjustment cycle, and the corrected Tes value is generally not lower than the Tes value calculated according to the default value of x minus 4℃; The value of △t2 must meet the reliability requirements in the compressor specification. At the same time, it is not advisable to leave too much margin, so that Te can be maintained at a high value as much as possible.

5. The ultra-low pressure ratio operation energy-saving control method of the energy storage battery liquid cooling unit according to claim 1 is characterized in that: In S2, based on the relationship between the return air pressure saturation temperature value and the return air pressure saturation temperature value, the control parameters of the electronic expansion valve (7) are determined, including: When the return air pressure saturation temperature value is greater than the sum of the return air pressure saturation temperature value and the return temperature difference, the electronic expansion valve (7) is controlled to be closed; When the return air pressure saturation temperature value is equal to the sum of the return air pressure saturation temperature value and the return temperature difference, the current opening of the electronic expansion valve (7) is kept unchanged; When the return air pressure saturation temperature value is less than the sum of the return air pressure saturation temperature value and the return temperature difference, the electronic expansion valve (7) is controlled to open wider.

6. The ultra-low pressure ratio operation energy-saving control method of the energy storage battery liquid cooling unit according to claim 1 is characterized in that: In S3, based on the working parameters, the exhaust pressure saturation temperature target value is calculated, including: Based on the working parameters, the exhaust pressure saturation temperature target value is calculated according to the following formula; Tcs=max(T1+△t3、y*Pes) Wherein, Tcs represents the exhaust pressure saturation temperature target value, T1 represents the ambient temperature value, Pes represents the return air pressure saturation temperature target value, the y value is determined according to the minimum pressure ratio allowed by the compressor specification, generally 1.1 to 1.3, and △t3 is generally 5 to 10; When the compressor (1) is turned off, the y value returns to the default value. After the compressor (1) is turned on, the y value is corrected according to the return air pressure saturation temperature Te: When Te<Tes-a, and the opening of the electronic expansion valve exceeds 70% of its maximum opening, the y value is increased by 0.1 on the basis of the current real-time value in each adjustment cycle. The corrected y value should always be limited to the maximum correction value on the basis of the default value. Generally, the corrected y value does not exceed 1.5-1.8, and a is generally 0-2; When Tes≥Te≥Tes-a, the y value maintains the current real-time value; When Te>Tes, the y value is reduced by 0.1 based on the current real-time value in each adjustment cycle. The corrected y value is always not less than the default value. Generally, the corrected y value is ≥1.

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7. The ultra-low pressure ratio operation energy-saving control method of the energy storage battery liquid cooling unit according to claim 1 is characterized in that: In S3, based on the exhaust pressure saturation temperature value and the relationship between the exhaust pressure saturation temperature value, the control parameters of the fan (10) are determined, including: When the exhaust pressure saturation temperature value is greater than the sum of the exhaust pressure saturation temperature value and the return temperature, controlling the fan (10) to increase the rotation speed; When the exhaust pressure saturation temperature value is equal to the sum of the exhaust pressure saturation temperature value and the return temperature, the rotation speed of the fan (10) is controlled to remain unchanged; When the exhaust pressure saturation temperature value is less than the sum of the exhaust pressure saturation temperature value and the return temperature, the fan (10) is controlled to reduce the rotation speed.

8. The ultra-low pressure ratio operation energy-saving control method of the energy storage battery liquid cooling unit according to claim 1 is characterized in that: Also includes: Obtaining the operating pressure ratio of the compressor (1) under the operation of the control parameters of the electronic expansion valve (7) and the control parameters of the fan (10); Based on the relationship between the operating pressure ratio and the preset operating pressure ratio, the control parameters are fine-tuned.

9. The ultra-low pressure ratio operation energy-saving control method of the energy storage battery liquid cooling unit according to claim 8 is characterized in that: The fine-tuning of the control parameters based on the relationship between the operating pressure ratio and the preset operating pressure ratio includes: When the operating pressure ratio is less than or equal to the preset operating pressure ratio, the control parameter is not adjusted; When the operating pressure ratio is greater than the preset operating pressure ratio, the control parameter to be adjusted when the operating pressure ratio is greater than the preset operating pressure ratio is obtained, and the control parameter to be adjusted is fine-tuned based on the operating pressure ratio-parameter curve diagram.

10. The ultra-low pressure ratio operation energy-saving control method of the energy storage battery liquid cooling unit according to claim 9, characterized in that: Based on the operating pressure ratio-parameter curve diagram, fine-tuning the control parameter to be adjusted includes: Based on the real-time collected real-time working parameters and real-time control parameters of the energy storage battery liquid cooling unit system, and by monitoring the operating pressure ratio under the real-time working parameters and real-time control parameters, an operating pressure ratio-parameter curve diagram is established; Obtaining a maximum operating pressure ratio and a first parameter corresponding thereto, and a minimum operating pressure ratio and a second parameter corresponding thereto from the operating pressure ratio-parameter curve diagram, determining an optimal parameter relationship between a first operating parameter and a first control parameter based on the first parameter, and determining a worst parameter relationship between a second operating parameter and a second control parameter based on the second parameter; Determine a first operating pressure ratio difference and a second operating pressure ratio difference between the operating pressure ratio and a maximum operating pressure ratio and a minimum operating pressure ratio, respectively; Based on the first operating pressure difference ratio, determining a control parameter adjustment range, based on the worst parameter relationship and in combination with the working parameters of the operating pressure ratio, determining a control parameter adjustment weight, and based on the control parameter adjustment range and the control parameter adjustment weight, determining fine-tuning data of the control parameter to be adjusted; Based on the second operating pressure difference ratio and the optimal parameter relationship, the fine-tuning data is verified and corrected to determine whether the parameter relationship between the control parameter adjusted according to the fine-tuning data and the working parameter of the operating pressure ratio is within a preset range from the optimal parameter relationship; If yes, fine-tune the control parameter to be adjusted according to the fine-tuning data; Otherwise, the fine-tuning data is corrected based on the second operating pressure difference ratio.

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