Control method and device for electronic expansion valve in electric engineering machine and electric engineering machine

Abstract

The invention provides a control method and device for an electronic expansion valve in an electric engineering machine and the electric engineering machine. The method comprises the steps that the first refrigerating capacity and the second refrigerating capacity of a battery in the electric engineering machine are obtained; wherein the first refrigerating capacity represents the refrigerating capacity required by the battery, and the second refrigerating capacity is a correction parameter of the refrigerating capacity of the battery; the first refrigerating capacity is related to the current heating capacity of the battery, and the current heating capacity represents the heating capacity of the battery at the current moment; the second refrigerating capacity is related to a first temperature parameter and a second temperature parameter of the battery, the first temperature parameter represents an average temperature value of a battery cell of the battery, and the second temperature parameter represents a temperature difference between a water inlet and a water outlet corresponding to the battery; according to the first refrigerating capacity and the second refrigerating capacity, the initial adjusting opening degree of the electronic expansion valve is corrected, and the target adjusting opening degree of the electronic expansion valve is obtained; and adjusting the opening degree of the electronic expansion valve according to the target adjustment opening degree so as to dissipate heat of the battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric engineering machinery, and in particular to a control method and device of an electronic expansion valve in electric engineering machinery and electric engineering machinery. BACKGROUND

[0002] During the operation of the electric engineering machinery, a large amount of heat is generated by the power battery, which needs to be effectively dissipated by the cooling system. Generally, the cooling system adopts a refrigeration cycle structure and is configured with an electronic expansion valve to regulate the refrigerant flow. By controlling the opening degree of the electronic expansion valve, the refrigerant can absorb the heat of the battery after throttling, thereby achieving the cooling of the battery.

[0003] In the prior art, the opening degree of the electronic expansion valve can be controlled according to the heat of the refrigerant.

[0004] However, in the above-mentioned manner, the opening degree of the electronic expansion valve is controlled only according to the heat of the refrigerant, which cannot make the refrigeration system effectively dissipate heat for the battery. SUMMARY

[0005] The embodiments of the present application provide a control method and device of an electronic expansion valve in electric engineering machinery and electric engineering machinery, so as to achieve the effect of better dissipating heat for the battery by the refrigeration system.

[0006] In a first aspect, the embodiments of the present application provide a control method of an electronic expansion valve in electric engineering machinery, comprising: obtaining a first refrigeration amount and a second refrigeration amount of a battery in the electric engineering machinery; wherein the first refrigeration amount represents the required refrigeration amount of the battery, and the second refrigeration amount is a correction parameter of the refrigeration amount of the battery; the first refrigeration amount is related to a current heat generation amount of the battery, and the current heat generation amount represents the heat generation amount of the battery at the current time; the second refrigeration amount is related to a first temperature parameter and a second temperature parameter of the battery, the first temperature parameter represents the average temperature value of the battery cell, and the second temperature parameter represents the temperature difference between the inlet and outlet of the battery; correcting an initial adjustment opening degree of the electronic expansion valve according to the first refrigeration amount and the second refrigeration amount, to obtain a target adjustment opening degree of the electronic expansion valve; wherein the initial adjustment opening degree is determined based on the superheat of the refrigerant in the refrigeration system for the battery; and adjusting the opening degree of the electronic expansion valve according to the target adjustment opening degree to dissipate heat for the battery.

[0007] In a possible implementation, the current heat generation amount of the battery in the electric engineering machinery and the heat exchange amount of the battery are obtained; wherein the heat exchange amount represents the heat exchange amount between the battery and the current environment; and the first refrigeration amount is determined according to the current heat generation amount and the heat exchange amount.

[0008] In a possible implementation, a first heat of the battery and current state information of the battery are detected; the first heat is a heat generated by an internal resistance of the battery under a current; a second heat corresponding to the current state information is determined according to the current state information and a first mapping relationship; the second heat is a chemical reaction heat of the battery; the first mapping relationship represents a corresponding relationship between state information of the battery and the second heat of the battery; and the current heat generation is determined according to the first heat and the second heat.

[0009] In a possible implementation, a flow of a heat sink for heat dissipation of the battery is obtained, and the second temperature parameter is obtained; the current heat generation is determined according to a preset correction coefficient, a specific heat capacity of the heat sink, the flow, and the second temperature parameter.

[0010] In a possible implementation, the first temperature parameter and the second temperature parameter are obtained; a second refrigeration capacity corresponding to the first temperature parameter and the second temperature parameter is determined according to the first temperature parameter, the second temperature parameter, and a second mapping relationship; the second mapping relationship represents a corresponding relationship among the first temperature parameter, the second temperature parameter, and the second refrigeration capacity.

[0011] In a possible implementation, an ambient temperature of a current environment in which the battery is located and a rotating speed of a compressor of the refrigeration system are obtained; a calibration parameter is determined according to a ratio of the ambient temperature to the rotating speed; and the initial adjustment opening of the electronic expansion valve is corrected according to the first refrigeration capacity, the second refrigeration capacity, and the calibration parameter, to obtain the target adjustment opening of the electronic expansion valve.

[0012] In a possible implementation, the target adjustment opening is n=(Qn+Qk)*k2+Nd; wherein Qn is the first refrigeration capacity, Qk is the second refrigeration capacity, k2 is the calibration parameter, and Nd is the initial adjustment opening.

[0013] In a second aspect, the embodiments of the present application provide a control device of an electronic expansion valve in an electric engineering machinery, comprising: an obtaining module, configured to obtain a first refrigerating capacity and a second refrigerating capacity of a battery in the electric engineering machinery; wherein the first refrigerating capacity represents a refrigerating capacity required by the battery, and the second refrigerating capacity is a correction parameter of the refrigerating capacity of the battery; the first refrigerating capacity is related to a current heat generation of the battery, and the current heat generation represents a heat generation of the battery at a current time; the second refrigerating capacity is related to a first temperature parameter and a second temperature parameter of the battery, the first temperature parameter represents an average temperature value of a battery cell of the battery, and the second temperature parameter represents a temperature difference between an inlet and an outlet of the battery; an adjusting module, configured to correct an initial adjusting opening degree of the electronic expansion valve according to the first refrigerating capacity and the second refrigerating capacity, to obtain a target adjusting opening degree of the electronic expansion valve; wherein the initial adjusting opening degree is determined based on a superheat degree of a refrigerant in a refrigerating system for refrigerating the battery; and a heat dissipation module, configured to adjust the opening degree of the electronic expansion valve according to the target adjusting opening degree, to dissipate heat for the battery.

[0014] In a third aspect, the embodiments of the present application provide a control device of an electronic expansion valve in an electric engineering machinery, comprising: a memory, and a processor;

[0015] The memory stores computer execution instructions;

[0016] The processor executes the computer execution instructions stored in the memory, so that the processor executes the first aspect and / or various possible implementation manners of the first aspect.

[0017] In a fourth aspect, the embodiments of the present application provide a computer readable storage medium, which stores computer execution instructions, and the computer execution instructions are executed by a processor to implement the first aspect and / or various possible implementation manners of the first aspect.

[0018] In a fifth aspect, the embodiments of the present application provide a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the first aspect and / or various possible implementation manners of the first aspect.

[0019] The control method of the electronic expansion valve in the electric engineering machinery provided by the embodiment of the application, the electronic device, the storage medium and the electric engineering machinery are as follows: firstly, a first refrigerating capacity required by a battery is acquired, which is related to the current heat generation of the battery and reflects the instant cooling demand of the battery. Meanwhile, a second refrigerating capacity is considered as a correction parameter, which is based on a first temperature parameter (average temperature of the battery cell) and a second temperature parameter (temperature difference between the inlet and outlet), and provides fine adjustment to the initial refrigerating demand. Then, the initial adjustment opening of the electronic expansion valve is corrected in combination with the two refrigerating capacities. The initial opening is determined according to the superheat of the refrigerant in the refrigerating system, and the corrected opening is closer to the actual heat dissipation demand of the battery. Finally, the electronic expansion valve is dynamically adjusted according to the target adjustment opening, so as to accurately control the refrigerant flow and realize effective heat dissipation of the battery. The process ensures that the refrigerating system can meet the instant cooling demand of the battery and flexibly adjust according to the state of the battery to achieve the target heat dissipation effect. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings incorporated by reference in the specification and forming a part thereof, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

[0021] Figure 1 The flowchart of the control method of the electronic expansion valve in the electric engineering machinery provided by the application Figure 1

[0022] Figure 2 The flowchart of the control method of the electronic expansion valve in the electric engineering machinery provided by the application Figure 2

[0023] Figure 3 The logic diagram of the calculation method of the control method of the electronic expansion valve in the electric engineering machinery provided by the application

[0024] Figure 4 The schematic diagram of the constituent parts of the control method of the electronic expansion valve in the electric engineering machinery provided by the application

[0025] Figure 5 The structural schematic diagram of the control device of the electronic expansion valve in the electric engineering machinery provided by the application

[0026] Figure 6 The structural schematic diagram of the control device of the electronic expansion valve in the electric engineering machinery provided by the application

[0027] Through the above drawings, the specific embodiments of the application have been shown, and more detailed descriptions will be given hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of the application by any means, but to illustrate the concept of the application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION​​

[0028] The exemplary embodiments will be described in detail herein with reference to the attached drawings. The description herein relates to the drawings, wherein the same numbers in different drawings represent the same or similar elements. The following exemplary embodiments are described in detail with reference to the accompanying drawings. The embodiments described in the following exemplary embodiments do not represent all the implementations in accordance with this application. Instead, they only describe example devices and methods in accordance with some aspects of this application, as detailed in the appended claims.

[0029] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0030] Figure 1 The flowchart of the control method of the electronic expansion valve in the electric engineering machinery provided by the present application is shown in FIG. 1, which comprises the following steps. Figure 1

[0031] S101, obtaining a first refrigeration amount and a second refrigeration amount of a battery in an electric engineering machinery.

[0032] The first refrigeration amount represents the refrigeration amount required by the battery, and the second refrigeration amount is a correction parameter of the refrigeration amount of the battery; the first refrigeration amount is related to the current heat generation amount of the battery, which represents the heat generation amount of the battery at the current time; the second refrigeration amount is related to a first temperature parameter and a second temperature parameter of the battery, the first temperature parameter representing the average temperature value of the battery cell, and the second temperature parameter representing the temperature difference between the inlet and the outlet of the battery.

[0033] Demand refrigeration amount (Qn) = current heat generation amount of battery (Qb) + environmental heat exchange amount (Qi)

[0034] Qb: current heat generation amount of battery, which refers to the total heat generated by the battery during operation due to internal resistance heat generation, chemical reaction heat generation, etc. (unit: W).

[0035] Qi: environmental heat exchange amount, which refers to the heat exchange amount between the battery pack and the environment (unit: W).

[0036] Qn: demand refrigeration amount, which refers to the total heat removed to maintain the battery temperature stable (unit: W).

[0037] ​It should be noted that the electric power machinery (especially electric excavator) is often in the working environment of high load, frequent start-stop and severe working condition changes, and the battery heat generation has strong transient and non-steady state characteristics. Therefore, it is difficult to accurately reflect the actual heat dissipation demand only by relying on the steady state model. By introducing the comprehensive calculation of Qi and Qb, the internal heat generation of the battery and the external environmental influence can be quantified, and a dynamic and accurate refrigeration target value is formed.

[0038] It should be noted that the current heat generation of the battery is a quantitative evaluation of the heat input generated by the battery itself. This is the basic heat source that needs to be removed first for any attempt to reduce the battery temperature.

[0039] The environmental heat exchange amount is to quantitatively evaluate the external influence net value of the environment on the battery temperature. The environment is a heat source (deteriorating heat dissipation demand) or a heat dissipation aid (reducing heat dissipation demand).

[0040] If Qi>0 (i.e. the environment temperature is higher than the battery pack, and the heat net flows in), it will increase the total amount of heat to be removed. The refrigeration system needs to work extra to resist the heat invasion of the environment.

[0041] If Qi<0 (i.e. the environment temperature is lower than the battery pack, and the heat net flows out), it will offset or reduce a part of the influence of the battery self-heat generation (Qb). At this time, the burden of the refrigeration system can be reduced, and even no full output is needed (depending on the size of negative Qi).

[0042] By calculating the required refrigeration amount, all heat sources that affect the stability of the battery temperature (internal generated Qb+external net input Qi) are integrated.

[0043] By calculating the minimum effective refrigeration capacity that the thermal management system (liquid cooling system, etc.) must theoretically achieve in order for the battery to reach (or maintain) thermal equilibrium state (temperature unchanged), it is the refrigeration "target value" required to maintain thermal equilibrium. Further, the complex battery heat dissipation demand is structured and formulated, which can be used for real-time control.

[0044] The first temperature parameter refers to the average temperature of the battery cell, which directly reflects the thermal equilibrium state of the battery body. The average temperature of the battery cell is the most core and fundamental index for measuring whether the battery is overheated, whether it needs to be cooled, and what level the cooling target needs to reach.

[0045] Through the average temperature of the battery cell, the calculation and regulation of the refrigeration amount are actually bound to the actual heat accumulation state of the main body (battery cell) that needs to be protected.

[0046] The second temperature parameter refers to the temperature difference between the inlet and outlet water, which directly reflects how much heat the cooling liquid carries away after flowing through the battery pack. Combined with the current cooling liquid flow information, this temperature difference can calculate the actual heat that the current refrigeration system can carry away, and compare it with the heat required to maintain temperature stability.

[0047] S102, according to the first refrigeration capacity and the second refrigeration capacity, the initial adjustment opening of the electronic expansion valve is corrected to obtain the target adjustment opening of the electronic expansion valve.

[0048] Wherein, the initial adjustment opening is determined based on the superheat of the refrigerant in the refrigeration system for cooling the battery.

[0049] It should be noted that the electronic expansion valve (EXV) is a key throttling device in the refrigeration system, which finely adjusts the refrigerant flow by changing the opening size (percentage of opening degree, such as 0-100%).

[0050] The initial adjustment opening is the opening of the electronic expansion valve determined based on the superheat of the refrigerant in the refrigeration system for cooling the battery. The superheat refers to the difference between the temperature of the refrigerant at the outlet of the evaporator and the saturation temperature at its corresponding pressure. According to this superheat, the initial adjustment position of the electronic expansion valve is determined to control the flow of refrigerant, thereby affecting the refrigeration effect of the refrigeration system.

[0051] The target adjustment opening is the final opening of the electronic expansion valve obtained by correcting the initial adjustment opening, which takes into account the required refrigeration capacity of the battery (first refrigeration capacity and second refrigeration capacity), so that the opening of the electronic expansion valve can better meet the heat dissipation needs of the battery.

[0052] That is, based on the first refrigeration capacity and the second refrigeration capacity obtained previously, the initial adjustment opening of the electronic expansion valve determined according to the superheat of the refrigerant is corrected. Because the initial opening is simply based on the superheat of the refrigerant, it does not fully consider the actual changes in refrigeration demand of the battery. By introducing the refrigeration capacity parameters related to the battery for correction, a target adjustment opening more suitable for the heat dissipation of the battery can be obtained, ensuring that the opening of the electronic expansion valve can make the refrigeration system output the refrigeration capacity that meets the current needs of the battery.

[0053] S103, according to the target adjustment opening, adjust the opening of the electronic expansion valve to dissipate heat for the battery.

[0054] Finally, according to the target adjustment opening calculated, the opening of the electronic expansion valve is actually adjusted. After the opening of the electronic expansion valve is changed, the flow of refrigerant in the refrigeration system will change accordingly, thereby adjusting the refrigeration effect of the refrigeration system, so that enough cold energy is transferred to the battery to carry away the heat generated by the battery, achieving effective heat dissipation for the battery and ensuring that the battery can work stably within the appropriate temperature range.

[0055] In other words, a battery generates heat during operation, and this heat generation determines the required basic cooling capacity, or the first cooling capacity. Simultaneously, the average cell temperature reflects the overall internal temperature of the battery, and the temperature difference between the inlet and outlet reflects the actual heat exchange effect of the cooling system. These two factors serve as correction parameters to derive the second cooling capacity. Combining both allows for a more accurate determination of the actual cooling capacity required by the battery.

[0056] For electronic expansion valves, the initial adjustment opening is based solely on refrigerant superheat, which fails to adequately account for the complex and fluctuating cooling demands of the battery. By adjusting the initial opening in conjunction with relevant battery cooling capacity parameters, the resulting target adjustment opening allows the electronic expansion valve to more precisely control the refrigerant flow. In this way, the refrigeration system can output the appropriate cooling capacity based on the battery's real-time heating and temperature, effectively removing the heat generated by the battery, ensuring the battery remains within its optimal operating temperature range, improving battery performance and lifespan, and achieving efficient and precise thermal management of electric engineering machinery batteries.

[0057] In summary, the control method for the electronic expansion valve in electric construction machinery provided in this application is particularly suitable for high-dynamic operating scenarios such as electric excavators. By integrating multi-dimensional information such as the battery's own heat generation, environmental thermal interference, average cell temperature, and cooling circuit temperature difference, the traditional overheat-based control strategy is refined, overcoming problems such as delayed cooling response and mismatched cooling supply in existing technologies. This significantly improves the accuracy and energy efficiency of battery thermal management, effectively ensuring the battery safety and lifespan of electric construction machinery under complex operating conditions.

[0058] The control method for the electronic expansion valve in electric engineering machinery provided in this application obtains the first cooling capacity (based on the current heat generation) and the second cooling capacity (correction parameter, related to the average temperature of the battery cell and the temperature difference between the inlet and outlet water ports) of the battery, corrects the initial adjustment opening of the electronic expansion valve (determined based on the superheat of the refrigerant), obtains the target adjustment opening, and then adjusts the opening of the electronic expansion valve to achieve a means of heat dissipation for the battery, thereby effectively improving the heat dissipation effect of the refrigeration system on the battery.

[0059] Figure 2 A flowchart illustrating the control method for the electronic expansion valve in electric engineering machinery provided in this application. Figure 2 ,like Figure 2 As shown, in this embodiment... Figure 1 Based on the embodiments, a detailed description of the control method for electronic expansion valves in electric engineering machinery is provided. This method includes:

[0060] S201, acquire a current heat generation of a battery in the electric engineering machinery and a heat exchange of the battery; determine a first refrigeration capacity according to the current heat generation and the heat exchange.

[0061] The heat exchange represents a heat exchange between the battery and a current environment.

[0062] The current heat generation refers to heat generated by the battery in the electric engineering machinery due to internal electrochemical reactions (such as charging and discharging processes), internal resistance and other factors at the current moment, which reflects the amount of heat generated by the battery at the moment and is a key indicator of the battery heat state, which changes with different working conditions of the battery (such as acceleration, deceleration, charging, discharging, etc.) and the ambient temperature.

[0063] The heat exchange represents the amount of heat exchange between the battery and the current environment, that is, the value of heat dissipation or absorption of the battery from the surrounding environment, which is affected by the temperature difference between the battery surface and the environment, the heat dissipation area, the air flow and other factors, and reflects the degree of heat exchange between the battery and the external environment.

[0064] Exemplarily, a first heat of the battery and current state information of the battery are detected; wherein the first heat is the heat generated by the internal resistance of the battery under the current; according to the current state information and the first mapping relationship, a second heat corresponding to the current state information is determined; wherein the second heat is the chemical reaction heat of the battery; the first mapping relationship represents the corresponding relationship between the state information of the battery and the second heat of the battery; and according to the first heat and the second heat, the current heat generation is determined.

[0065] The first heat refers to the heat generated by the internal resistance of the battery when the current passes through, according to the Joule law (Q = I2Rt), which reflects the part of heat energy converted from the current flowing through the internal resistance, and is a component of the heat generated by the battery. Wherein Q is the heat, I is the current, R is the resistance, and t is the time.

[0066] The second heat represents the heat generated by the chemical reaction of the battery, such as the heat released by the chemical reaction of lithium ions embedding and de-embedding between the positive and negative electrodes during charging and discharging of lithium ion battery, which is also an important component of the overall heat generated by the battery.

[0067] The current state information contains a variety of parameter information reflecting the current status of the battery, such as the voltage, temperature, state of charge (SOC, i.e. the proportion of the remaining battery capacity to the full battery capacity) of the battery, etc. These information comprehensively presents the working and health status of the battery at the moment, which can be used for further analysis of the heat generation of the battery.

[0068] The first mapping relationship is a pre-established corresponding association, which clearly defines the matching relationship between different state information of the battery (such as different voltage, temperature, SOC combination, etc.) and the corresponding generated chemical reaction heat (second heat). By looking up the mapping relationship, the corresponding chemical reaction heat can be known according to the real-time state information of the battery.

[0069] First, the battery is detected, on the one hand, to obtain the first heat of the battery, which requires measuring the current size of the battery at the current working time and knowing the internal resistance parameter of the battery, and then using the above-mentioned Joule law related principle to calculate the heat generated by the internal resistance; on the other hand, the current state information of the battery is collected, and various corresponding sensors (such as voltage sensor to measure voltage, temperature sensor to measure temperature, and power monitoring device to obtain SOC) are used to collect comprehensive battery state data.

[0070] Next, according to the current state information of the battery that has been obtained, the mapping relationship that has been constructed in advance is checked, so as to determine the corresponding second heat, that is, to clearly determine the heat value generated by the chemical reaction of the battery under the state.

[0071] Finally, the first heat (internal resistance heat) calculated and the second heat (chemical reaction heat) determined through the mapping relationship are added, and the sum of the two is the current heat of the battery, so as to accurately know the total heat generated by the battery at the moment, and to provide a key data basis for subsequent battery thermal management and related control.

[0072] Exemplarily, the flow of the heat dissipation agent for dissipating heat for the battery is obtained, and a second temperature parameter is obtained; according to a preset correction coefficient, a specific heat capacity of the heat dissipation agent, the flow, and the second temperature parameter, a current heat is determined.

[0073] The flow of the heat dissipation agent refers to the volume of the heat dissipation agent (such as cooling liquid, etc.) flowing through a specific pipeline or area per unit time for dissipating heat for the battery, for example: measured in units of liters / minute, cubic meters / hour, etc., which reflects the speed of the circulation of the heat dissipation agent, and has an important influence on the ability to take away the heat of the battery.

[0074] The second temperature parameter refers to the temperature difference between the inlet and the outlet of the battery, which is obtained by measuring the temperature of the heat dissipation agent flowing into the inlet of the battery and the temperature of the heat dissipation agent flowing out of the outlet, and the temperature difference is obtained by subtracting the two, which can reflect the actual heat taking away effect of the heat dissipation agent in the heat exchange process with the battery.

[0075] The preset correction coefficient is a coefficient determined in advance according to a large amount of experimental data, theoretical calculation and actual experience, and is used to appropriately correct the formula result of calculating the current heat generation based on other parameters under different working conditions, so that the finally calculated current heat generation is more consistent with the real heat generation of the battery.

[0076] The specific heat capacity of the heat sink represents the amount of heat absorbed by unit mass of the heat sink when the temperature is raised by unit temperature. Different types of heat sinks have different specific heat capacity characteristics, which is a key physical quantity for measuring the heat absorption capacity of the heat sink and plays an important role in calculating how much heat the heat sink carries away.

[0077] The current heat generation is the total heat generated by the battery at the current moment due to various factors such as internal resistance and chemical reaction, which is a key indicator that needs to be accurately obtained to provide a basis for subsequent reasonable control of battery cooling and other operations.

[0078] Firstly, two key parameters need to be obtained. One is the flow rate of the heat sink for battery cooling, which can be measured by a flow meter installed on the heat sink conveying pipeline, so as to know how much heat sink is circulating in the battery cooling process per unit time. The second is to obtain the second temperature parameter, that is, to measure the inlet temperature and outlet temperature of the heat sink entering and flowing out of the battery cooling part respectively by using a temperature sensor, and then calculate the temperature difference.

[0079] Then, combined with the known specific heat capacity of the heat sink as an inherent attribute parameter, and considering the pre-set correction coefficient, the corresponding heat calculation is carried out:

[0080] Q = c x m x ΔT

[0081] c is the specific heat capacity, m can be converted from the flow rate to the mass in the corresponding time period, ΔT is the second temperature parameter, and the result is multiplied by the correction coefficient for adjustment. By substituting these parameters into the operation, the current heat generation of the battery is finally determined to accurately grasp the heat generation of the battery at the moment, and to provide accurate data support for further optimizing the battery cooling control strategy.

[0082] S202, obtain a first temperature parameter and a second temperature parameter; determine a second refrigerating capacity corresponding to the first temperature parameter and the second temperature parameter according to the first temperature parameter, the second temperature parameter, and a second mapping relationship.

[0083] The second mapping relationship represents the corresponding relationship among the first temperature parameter, the second temperature parameter, and the second refrigerating capacity.

[0084] The second mapping relationship is a pre-established corresponding association rule, which clearly defines the matching relationship between the first temperature parameter, the second temperature parameter of the battery and the corresponding second refrigerating capacity. By looking up the mapping relationship, the appropriate second refrigerating capacity can be determined according to the two temperature parameters obtained in real time.

[0085] The second refrigerating capacity, as a correction parameter of the battery refrigerating capacity, is determined based on considering the battery cell temperature and the refrigerating system inlet and outlet temperature difference, and is used to more accurately adjust the refrigerating capacity required by the battery as a whole, so as to ensure that the battery can work at an appropriate temperature.

[0086] In S203, the ambient temperature of the current environment where the battery is located and the rotating speed of the compressor of the refrigerating system are obtained; a calibration parameter is determined according to the ratio of the ambient temperature to the rotating speed; and the initial adjustment opening degree of the electronic expansion valve is corrected according to the first refrigerating capacity, the second refrigerating capacity and the calibration parameter, so as to obtain the target adjustment opening degree of the electronic expansion valve.

[0087] The calibration parameter refers to a reference parameter for correcting the opening degree of the electronic expansion valve, which is obtained by ratio operation of the ambient temperature and the rotating speed of the compressor. It comprehensively considers the external environment and the running state of the refrigerating system, and can make the subsequent adjustment of the opening degree of the electronic expansion valve more suitable for the actual complex working conditions.

[0088] Firstly, two key information are obtained, one is the ambient temperature of the current environment where the battery is located, which can be measured by means of an ambient temperature sensor; the other is the rotating speed of the compressor in the refrigerating system, which is obtained by a corresponding rotating speed monitoring device. Then, the ratio of the two data is calculated to determine the calibration parameter. Next, combined with the first refrigerating capacity of the battery (determined according to the battery heat generation and other factors) and the second refrigerating capacity (determined by considering the cell temperature and the inlet and outlet temperature difference and other factors), and the calibration parameter calculated just now, the initial adjustment opening degree of the electronic expansion valve determined based on the refrigerant superheat degree is corrected according to a specific algorithm or rule. After such comprehensive adjustment, the target adjustment opening degree of the electronic expansion valve is finally obtained, so as to accurately control the refrigerant flow, realize efficient and accurate heat dissipation of the battery, and ensure stable work of the battery.

[0089] Exemplarily, the target adjustment opening degree is n=(Qn+Qk)*k2+Nd; wherein Qn is the first refrigerating capacity, Qk is the second refrigerating capacity, k2 is the calibration parameter, and Nd is the initial adjustment opening degree. The logic diagram of the calculation method can be seen from Figure 3 , Figure 3This is a schematic diagram illustrating the calculation method for the control of the electronic expansion valve in the electric engineering machinery provided in this application. This control method calculates the total cooling capacity and dynamically corrects it based on environmental and battery state parameters to ultimately determine the target opening degree of the cooling system, thereby achieving precise control of the battery pack temperature.

[0090] The required cooling capacity Qn consists of two parts:

[0091] Internal resistance heat generation Qb: reflects the Joule heat generated by the battery due to its internal resistance during charging and discharging;

[0092] The heat generated by the chemical reaction, Qi, reflects the heat released by the electrochemical reaction inside the battery. The two are added together to form the initial required cooling capacity, Qn.

[0093] The corrected cooling capacity Qk is a dynamic correction term introduced based on real-time operating conditions, and its input parameters include:

[0094] Average cell temperature Tavg: characterizes the overall thermal state of the battery;

[0095] The temperature difference between the battery inlet and outlet water, δT, reflects the heat exchange efficiency of the cooling circuit.

[0096] The total cooling capacity is the sum of the required cooling capacity Qn and the corrected cooling capacity Qk, and is used to make a preliminary estimate of the cooling capacity required by the system.

[0097] The total cooling capacity is multiplied by a calibration coefficient K (K is a preset constant that can be calibrated according to system characteristics) to obtain the basic opening degree, which serves as the basic control command for the cooling system.

[0098] At the same time, the system detects refrigerant pressure and temperature, calculates superheat, and uses this value as a feedback signal to participate in control.

[0099] The superheat is processed to generate a corrected opening degree, which is then added to the base opening degree to form the final target opening degree, which is used to drive actuators such as electronic expansion valves to regulate the refrigerant flow.

[0100] This control strategy achieves closed-loop matching between cooling demand and actual heat exchange status, improving the response accuracy and energy efficiency of the battery thermal management system.

[0101] Examples of the components and relationships of the entire system are as follows: Figure 4 As shown, Figure 4 A schematic diagram of the components constituting the control method for the electronic expansion valve in electric engineering machinery provided in this application.

[0102] This figure illustrates a liquid cooling cycle system structure for thermal management of power batteries, including a heat exchange path between the cooling circuit and the battery pack, to achieve effective control of battery temperature.

[0103] The system mainly consists of the following components: compressor: drives the refrigerant to circulate in the system and provides cooling power;

[0104] Condenser: Located on the high-pressure side, it is used to cool the high-temperature, high-pressure gaseous refrigerant into a liquid state, while simultaneously dissipating heat to the outside.

[0105] Electronic expansion valve: As a throttling device, it adjusts the refrigerant flow according to the control signal to achieve precise control of the evaporation temperature;

[0106] Plate heat exchanger: a key heat exchange component, with refrigerant (low-temperature, low-pressure liquid) flowing on one side and battery coolant (water or water-glycol mixture) flowing on the other side, achieving efficient heat transfer from battery coolant to refrigerant;

[0107] Water pump: Drives the battery coolant to circulate between the battery pack and the heat exchanger;

[0108] Battery pack: The object to be cooled, with cooling channels inside, through which coolant flows to carry away heat;

[0109] Water bottle: Used to replenish coolant and to contain volume changes caused by thermal expansion and contraction of the system;

[0110] Sensor placement:

[0111] Temperature sensors are installed at the inlet and outlet of the battery pack to monitor the inlet and outlet temperatures of the coolant and assess the battery's thermal load.

[0112] Temperature and pressure sensors are installed on the high-pressure side (from the compressor outlet to the condenser inlet) to monitor the high-pressure state of the refrigerant;

[0113] Temperature and pressure sensors are installed on the low-pressure side (from the plate heat exchanger outlet to the compressor inlet) to monitor the low-pressure state of the refrigerant and help determine the system's operating status.

[0114] Coolant circulation path: water pump → heat exchanger → battery pack → coolant reservoir → water pump, forming a closed loop.

[0115] The refrigerant circulation path is: compressor → condenser → electronic expansion valve → plate heat exchanger → compressor, which constitutes a standard refrigeration cycle.

[0116] This system achieves indirect cooling through a dual-circulation structure (refrigerant circulation and coolant circulation), offering advantages such as high safety, excellent temperature control performance, and low maintenance costs. It is suitable for high-power battery applications such as electric engineering machinery.

[0117] The control method for the electronic expansion valve in electric engineering machinery provided in this application first obtains the first cooling capacity required by the battery. This value is related to the current heat generation of the battery and reflects the battery's immediate cooling demand. Simultaneously, a second cooling capacity is considered as a correction parameter. This parameter is based on the battery's first temperature parameter (average cell temperature) and second temperature parameter (temperature difference between the inlet and outlet), providing fine-tuning for the initial cooling demand. Next, the initial adjustment opening of the electronic expansion valve is corrected by combining these two cooling capacities. The initial opening is determined based on the superheat of the refrigerant in the refrigeration system, while the corrected opening more closely matches the battery's actual heat dissipation needs. Finally, the electronic expansion valve is dynamically adjusted according to the target adjustment opening, thereby precisely controlling the refrigerant flow and achieving effective battery heat dissipation. This process ensures that the refrigeration system can both meet the battery's immediate cooling needs and flexibly adjust according to the battery's state to achieve the target heat dissipation effect.

[0118] Figure 5 This is a schematic diagram of the control device for the electronic expansion valve in the electric engineering machinery provided in this application, as shown below. Figure 5 As shown, the control device 40 for the electronic expansion valve in the electric engineering machinery provided in this embodiment includes:

[0119] The acquisition module 401 is used to acquire the first cooling capacity and the second cooling capacity of the battery in the electric engineering machinery; wherein, the first cooling capacity represents the cooling capacity required by the battery, and the second cooling capacity is a correction parameter of the cooling capacity of the battery; the first cooling capacity is related to the current heat generation of the battery, which represents the heat generated by the battery at the current moment; the second cooling capacity is related to the first temperature parameter and the second temperature parameter of the battery, where the first temperature parameter represents the average temperature value of the battery cell, and the second temperature parameter represents the temperature difference between the corresponding inlet and outlet of the battery.

[0120] The adjustment module 402 is used to correct the initial adjustment opening of the electronic expansion valve according to the first cooling capacity and the second cooling capacity to obtain the target adjustment opening of the electronic expansion valve; wherein, the initial adjustment opening is determined based on the superheat of the refrigerant in the refrigeration system for cooling the battery.

[0121] The heat dissipation module 403 is used to adjust the opening degree of the electronic expansion valve according to the target, so as to dissipate heat from the battery.

[0122] In one possible implementation, the acquisition module 401 is used to acquire the current heat generation and heat exchange of the battery in the electric engineering machinery; wherein the heat exchange characterizes the heat exchange between the battery and the current environment; and to determine a first cooling capacity based on the current heat generation and heat exchange.

[0123] In one possible implementation, the acquisition module 401 is used to detect the first heat of the battery and the current state information of the battery; wherein the first heat is the heat generated by the internal resistance of the battery under the current current; and to determine the second heat corresponding to the current state information according to the current state information and a first mapping relationship; wherein the second heat is the heat generated by the chemical reaction of the battery; the first mapping relationship characterizes the correspondence between the state information of the battery and the second heat of the battery; and to determine the current heat generation according to the first heat and the second heat.

[0124] In one possible implementation, the acquisition module 401 is used to acquire the flow rate of the heat transfer fluid used to dissipate heat from the battery and acquire a second temperature parameter; and determine the current heat generation based on a preset correction coefficient, the specific heat capacity of the heat transfer fluid, the flow rate, and the second temperature parameter.

[0125] In one possible implementation, the acquisition module 401 is used to acquire a first temperature parameter and a second temperature parameter; and determine a second cooling capacity corresponding to the first temperature parameter and the second temperature parameter based on the first temperature parameter, the second temperature parameter, and a second mapping relationship; wherein the second mapping relationship represents the correspondence between the first temperature parameter, the second temperature parameter, and the second cooling capacity.

[0126] In one possible implementation, the device further includes: a correction module (not shown) for acquiring the ambient temperature of the current environment where the battery is located and the rotational speed of the compressor of the refrigeration system; determining calibration parameters based on the ratio of ambient temperature to rotational speed; and correcting the initial adjustment opening of the electronic expansion valve based on the first cooling capacity, the second cooling capacity, and the calibration parameters to obtain the target adjustment opening of the electronic expansion valve.

[0127] In one possible implementation, the target adjustment opening is n = (Qn + Qk) * k2 + Nd; where Qn is the first cooling capacity, Qk is the second cooling capacity, k2 is the calibration parameter, and Nd is the initial adjustment opening.

[0128] The control device for the electronic expansion valve in the electric engineering machinery provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0129] Figure 6 This is a structural schematic diagram of the control device for the electronic expansion valve in the electric engineering machinery provided in this application. Figure 6 As shown, the electronic device 50 provided in this embodiment includes at least one processor 501 and a memory 502. Optionally, the device 50 further includes a communication component 503. The processor 501, memory 502, and communication component 503 are connected via a bus 504.

[0130] In a specific implementation, at least one processor 501 executes computer execution instructions stored in memory 502, causing at least one processor 501 to perform the above-described method.

[0131] The specific implementation process of processor 501 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It will not be repeated here.

[0132] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0133] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0134] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0135] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0136] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0137] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0138] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0139] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0140] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0141] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0142] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0143] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0144] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A control method for an electronic expansion valve in electric engineering machinery, characterized in that, The method includes: The first cooling capacity and the second cooling capacity of the battery in the electric engineering machinery are obtained; wherein, the first cooling capacity represents the cooling capacity required by the battery, and the second cooling capacity is a correction parameter of the cooling capacity of the battery; the first cooling capacity is related to the current heat generation of the battery, which represents the heat generated by the battery at the current moment; the second cooling capacity is related to the first temperature parameter and the second temperature parameter of the battery, where the first temperature parameter represents the average temperature value of the battery cell, and the second temperature parameter represents the temperature difference between the corresponding inlet and outlet of the battery. Based on the first cooling capacity and the second cooling capacity, the initial adjustment opening of the electronic expansion valve is corrected to obtain the target adjustment opening of the electronic expansion valve; wherein, the initial adjustment opening is determined based on the superheat of the refrigerant in the refrigeration system cooling the battery; Adjust the opening degree of the electronic expansion valve according to the target to dissipate heat from the battery.

2. The method according to claim 1, characterized in that, The acquisition of the first cooling capacity of the battery in the electric construction machinery includes: The current heat generation and heat exchange of the battery in the electric construction machinery are obtained; wherein the heat exchange represents the heat exchange between the battery and the current environment. The first cooling capacity is determined based on the current heat generation and the heat exchange.

3. The method according to claim 2, characterized in that, The acquisition of the current heat generation of the battery in the electric construction machinery includes: The first heat of the battery and the current state information of the battery are detected; wherein, the first heat is the heat generated by the internal resistance of the battery under the current current; Based on the current state information and the first mapping relationship, a second heat corresponding to the current state information is determined; wherein, the second heat is the chemical reaction heat of the battery; the first mapping relationship characterizes the correspondence between the battery's state information and the battery's second heat. The current heat output is determined based on the first heat output and the second heat output.

4. The method according to claim 2, characterized in that, The acquisition of the current heat generation of the battery in the electric construction machinery includes: The flow rate of the heat transfer fluid used to dissipate heat from the battery is obtained, and the second temperature parameter is obtained; The current heat output is determined based on a preset correction factor, the specific heat capacity of the heat exchanger, the flow rate, and the second temperature parameter.

5. The method according to claim 1, characterized in that, The acquisition of the second cooling capacity of the battery in the electric construction machinery includes: Obtain the first temperature parameter and the second temperature parameter; Based on the first temperature parameter, the second temperature parameter, and the second mapping relationship, determine the second cooling capacity corresponding to the first temperature parameter and the second temperature parameter; The second mapping relationship represents the correspondence between the first temperature parameter, the second temperature parameter, and the second cooling capacity.

6. The method according to any one of claims 1-5, characterized in that, Based on the first cooling capacity and the second cooling capacity, the initial adjustment opening of the electronic expansion valve is corrected to obtain the target adjustment opening of the electronic expansion valve, including: The ambient temperature of the current environment where the battery is located and the speed of the compressor of the refrigeration system are obtained; The calibration parameters are determined based on the ratio of the ambient temperature to the rotational speed. Based on the first cooling capacity, the second cooling capacity, and the calibration parameters, the initial adjustment opening of the electronic expansion valve is corrected to obtain the target adjustment opening of the electronic expansion valve.

7. A control device for an electronic expansion valve in electric engineering machinery, characterized in that, include: The acquisition module is used to acquire the first cooling capacity and the second cooling capacity of the battery in the electric engineering machinery; wherein, the first cooling capacity represents the cooling capacity required by the battery, and the second cooling capacity is a correction parameter of the cooling capacity of the battery; the first cooling capacity is related to the current heat generation of the battery, which represents the heat generated by the battery at the current moment; the second cooling capacity is related to the first temperature parameter and the second temperature parameter of the battery, where the first temperature parameter represents the average temperature value of the battery cell, and the second temperature parameter represents the temperature difference between the corresponding inlet and outlet of the battery. An adjustment module is used to correct the initial adjustment opening of the electronic expansion valve based on the first cooling capacity and the second cooling capacity to obtain the target adjustment opening of the electronic expansion valve; wherein the initial adjustment opening is determined based on the superheat of the refrigerant in the refrigeration system for cooling the battery. A heat dissipation module is used to adjust the opening degree of the electronic expansion valve according to the target, so as to dissipate heat from the battery.

8. A control device for an electronic expansion valve in electric engineering machinery, characterized in that, include: Memory, processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1-6.

10. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method described in any one of claims 1-6.

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