Environmental test box and linear cooling control method thereof

Abstract

The invention discloses an environmental test box and a linear cooling control method thereof. The control method comprises the following steps: acquiring a current state parameter of a to-be-controlled environment test box; acquiring a linear cooling parameter of the to-be-controlled environment test box, and determining a linear cooling rate; according to the current state parameter, the linear cooling parameter and the linear cooling rate, the compressor rotating speed, the electronic expansion valve opening degree, the evaporator fan rotating speed and the condenser fan rotating speed of the environment test box to be controlled are calculated; based on the rotating speed of the compressor, the opening degree of the electronic expansion valve, the rotating speed of the evaporator fan and the rotating speed of the condenser fan, the compressor, the electronic expansion valve, the evaporator fan and the condenser fan of the to-be-controlled environment test box are controlled to act, and linear cooling control over the to-be-controlled environment test box is achieved. According to the embodiment of the invention, the problems of poor operation reliability and high energy consumption of the refrigeration system in the linear cooling process can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature control, and in particular to an environmental test box and a linear temperature reduction control method thereof. Background Art

[0002] With the advancement of life and technology, the requirements for product reliability are getting higher and higher. Therefore, it is necessary to test the reliability, material stress changes, and material property changes of products or components when they are cooled from high temperature to low temperature within a certain period of time.

[0003] At present, fixed-frequency compressors are mostly used for linear cooling. Selecting the compressor according to the maximum cooling capacity requirement of the linear cooling process will result in higher overall compressor energy consumption during the linear cooling process. In addition, the cooling capacity changes greatly during the linear cooling process, and the control of the evaporator fan and condenser fan is also crucial. When the air volume of the evaporator fan and condenser fan is too small, it will affect the system operation reliability and cooling capacity. When the air volume is too large, the energy saving is poor. Therefore, optimizing the control and operation of the refrigeration system during the linear cooling process is crucial to improving the reliability of the refrigeration system operation and reducing the energy consumption of the refrigeration system operation. Summary of the invention

[0004] The invention provides an environmental test box and a linear temperature reduction control method thereof, so as to solve the problems of poor operation reliability and high energy consumption of a refrigeration system of the environmental test box during a linear temperature reduction process.

[0005] According to one aspect of the present invention, a linear temperature reduction control method for an environmental test chamber is provided, characterized in that it includes:

[0006] Obtaining current state parameters of the controlled environment test box; wherein the current state parameters include the current temperature in the box, the current suction pressure of the compressor, and the current exhaust pressure of the compressor;

[0007] Obtaining the linear cooling parameters of the controlled environment test box and determining the linear cooling rate;

[0008] According to the current state parameter, the linear temperature drop parameter and the linear temperature drop rate, respectively calculating the compressor speed, the electronic expansion valve opening, the evaporator fan speed and the condenser fan speed of the controlled environment test box;

[0009] Based on the compressor speed, the electronic expansion valve opening, the evaporator fan speed and the condenser fan speed, the compressor, electronic expansion valve, evaporator fan and condenser fan of the controlled environmental test box are controlled respectively to achieve linear temperature reduction control of the controlled environmental test box.

[0010] Optionally, the compressor speed, the electronic expansion valve opening, the evaporator fan speed, and the condenser fan speed of the controlled environment test box are calculated respectively according to the current state parameter, the linear cooling parameter, and the linear cooling rate, including:

[0011] Calculating the compressor speed according to the current temperature in the box, the current exhaust pressure of the compressor, the linear temperature reduction parameter and the linear temperature reduction rate;

[0012] Calculating the opening of the electronic expansion valve according to the current state parameter, the compressor speed, the linear temperature drop parameter and the linear temperature drop rate;

[0013] Calculating the evaporator fan speed according to the electronic expansion valve opening, the compressor speed, the current suction pressure of the compressor and the linear temperature reduction parameter;

[0014] The condenser fan speed is calculated according to the compressor speed and the current exhaust pressure of the compressor.

[0015] Optionally, the linear cooling parameters include a starting temperature, an ending temperature and a total cooling time;

[0016] The calculating the compressor speed according to the current temperature in the box, the current exhaust pressure of the compressor, the linear temperature reduction parameter and the linear temperature reduction rate includes:

[0017] Calculating the compressor speed using a compressor speed formula according to the current temperature in the box, the current exhaust pressure of the compressor, the starting temperature, the ending temperature, the linear cooling rate and the cooling time;

[0018] The compressor speed formula is expressed as:

[0019]

[0020] Among them, F min is the minimum speed of the compressor; F max is the maximum speed of the compressor; V is the linear cooling rate; τ is the cooling time; T0 is the starting temperature; T is the current temperature in the box; T sv is the final temperature; HP is the current exhaust pressure of the compressor; HP F0 The reference exhaust pressure for compressor speed control; a F , b F 、c F Both are equity coefficients.

[0021] Optionally, the linear cooling parameters include a starting temperature, an ending temperature and a total cooling time;

[0022] The calculating the opening of the electronic expansion valve according to the current state parameter, the compressor speed, the linear temperature drop parameter and the linear temperature drop rate comprises:

[0023] Calculating the electronic expansion valve opening degree using an electronic expansion valve opening degree formula according to the current state parameter, the compressor speed, the starting temperature, the ending temperature, the linear cooling rate and the cooling time;

[0024] The electronic expansion valve opening formula is expressed as:

[0025]

[0026] Among them, E min E is the minimum opening of the electronic expansion valve; max is the maximum opening of the electronic expansion valve; V is the linear cooling rate; τ is the cooling time; T0 is the starting temperature; T is the current temperature in the box; T sv is the final temperature; HP is the current exhaust pressure of the compressor; LP is the current suction pressure of the compressor; F is the compressor speed; F max is the maximum speed of the compressor; a E 、b E 、c E ,d E Both are equity coefficients.

[0027] Optionally, the linear cooling parameters include a starting temperature, an ending temperature and a total cooling time;

[0028] The step of calculating the evaporator fan speed according to the electronic expansion valve opening, the compressor speed, the current suction pressure of the compressor and the linear temperature reduction parameter comprises:

[0029] Calculating the evaporator fan speed using an evaporator fan speed formula according to the electronic expansion valve opening, the compressor speed, the current suction pressure of the compressor, the starting temperature and the ending temperature;

[0030] The evaporator fan speed formula is expressed as:

[0031]

[0032] Among them, A min is the minimum speed of the evaporator; A max is the maximum speed of the evaporator; E is the opening of the electronic expansion valve; E max is the maximum opening of the electronic expansion valve; T0 is the starting temperature; T is the current temperature in the box; T sv is the final temperature; LP is the current suction pressure of the compressor; LP A0 is the reference suction pressure for evaporator fan speed control; F is the compressor speed; Fmax is the maximum speed of the compressor; a A , b A 、c A Both are equity coefficients.

[0033] Optionally, calculating the condenser fan speed according to the compressor speed and the current exhaust pressure of the compressor includes:

[0034] Calculating the condenser fan speed using a condenser fan speed formula according to the compressor speed and the current exhaust pressure of the compressor;

[0035] The condenser fan speed formula is expressed as:

[0036]

[0037] Among them, C min is the minimum speed of the condenser; C max is the maximum speed of the condenser; F is the speed of the compressor; F max is the maximum speed of the compressor; HP is the current exhaust pressure of the compressor; HP C0 The reference exhaust pressure for condenser fan speed control; a C , b C Both are equity coefficients.

[0038] Optionally, the linear cooling parameters include a starting temperature, an ending temperature and a total cooling time;

[0039] Determining the linear cooling rate includes:

[0040] Subtract the final temperature from the initial temperature to determine the temperature change value;

[0041] The linear cooling rate is determined by dividing the temperature change value by the total cooling time.

[0042] According to another aspect of the present invention, an environmental test chamber is provided, comprising: a chamber, a control system and a refrigeration system; the refrigeration system is arranged in the chamber;

[0043] The control system is used to execute the linear temperature reduction control method of the environmental test box as described in any embodiment of the first aspect to control the operation of the refrigeration system.

[0044] Optionally, the refrigeration system includes a compressor, an electronic expansion valve, a condenser, a condenser fan, an evaporator and an evaporator fan;

[0045] The compressor, the condenser, the electronic expansion valve and the evaporator are connected in series in sequence to form a loop, the condenser fan is arranged at the condenser, and the evaporator fan is arranged at the evaporator.

[0046] Optionally, the control system includes a display unit, a data acquisition unit and a control unit;

[0047] The display unit is arranged on the surface of the box, the data acquisition unit is arranged inside the box, and the display unit and the data acquisition unit are electrically connected to the control unit respectively;

[0048] The data acquisition unit includes a temperature sensor, a compressor suction pressure sensor and a compressor exhaust pressure sensor; the temperature sensor is arranged inside the box, the compressor suction pressure sensor is arranged at the suction port of the compressor, and the compressor exhaust pressure sensor is arranged at the exhaust port of the compressor;

[0049] The control unit includes an acquisition and calculation control module, a compressor speed control module, an electronic expansion valve opening control module, an evaporator fan speed control module and a condenser fan speed control module;

[0050] The acquisition calculation control module is electrically connected to the sensor in the data acquisition unit, the compressor speed control module, the electronic expansion valve opening control module, the evaporator fan speed control module, and the condenser fan speed control module;

[0051] The compressor speed control module is electrically connected to the compressor;

[0052] The electronic expansion valve opening control module is electrically connected to the electronic expansion valve;

[0053] The evaporator fan speed control module is electrically connected to the evaporator fan;

[0054] The condenser fan speed control module is electrically connected to the condenser fan.

[0055] The linear cooling control method of the environmental test box provided by the embodiment of the present invention obtains the current state parameters of the environmental test box to be controlled, obtains the pre-set linear cooling parameters of the environmental test box to be controlled, and determines the linear cooling rate. According to the obtained current state parameters, linear cooling parameters and linear cooling rate, the compressor speed, electronic expansion valve opening, evaporator fan speed and condenser fan speed of the environmental test box to be controlled are accurately calculated. According to the calculated accurate compressor speed and electronic expansion valve opening, the compressor and electronic expansion valve of the refrigeration system in the environmental test box to be controlled are controlled, so that the refrigeration capacity of the compressor can be matched with the refrigeration capacity required in the linear cooling process, which is beneficial to reducing the energy consumption of the refrigeration system. According to the calculated accurate evaporator fan speed and condenser fan speed, the evaporator fan and condenser fan are controlled. When the evaporator and condenser operate normally during the linear cooling process, their own temperatures can be kept in a reasonable range, thereby helping to reduce the operating energy consumption of the evaporator fan and the condenser fan, and improve the reliability of the operation of the refrigeration system.

[0056] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0058] Figure 1 It is a flow chart of a linear temperature reduction control method of an environmental test chamber provided according to an embodiment of the present invention;

[0059] Figure 2 It is a specific flow chart of step S130 in a linear temperature reduction control method of an environmental test chamber provided according to an embodiment of the present invention;

[0060] Figure 3 It is a specific flow chart of step S120 in a linear temperature reduction control method of an environmental test chamber provided in an embodiment of the present invention;

[0061] Figure 4 It is a schematic diagram of the structure inside an environmental test box provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0062] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0063] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0064] An embodiment of the present invention provides a linear temperature reduction control method for an environmental test chamber. Figure 1 The following is a flow chart of a linear temperature reduction control method for an environmental test chamber provided by an embodiment of the present invention. Figure 1 As shown, the linear temperature reduction control method of the environmental test chamber specifically includes the following steps:

[0065] S110, obtaining current state parameters of the controlled environment test box; wherein the current state parameters include the current temperature in the box, the current suction pressure of the compressor, and the current exhaust pressure of the compressor.

[0066] Specifically, an environmental test chamber is a device used to simulate various environmental conditions to test the performance and reliability of products or materials in different environments. The controlled environmental test chamber is an environmental test chamber that needs to be controlled in the current experiment. The controlled environmental test chamber is equipped with a temperature sensor, a compressor suction pressure sensor, and a compressor exhaust pressure sensor. The current temperature inside the controlled environmental test chamber can be obtained through the monitoring of the temperature sensor; the current suction pressure of the compressor at the current temperature in the chamber can be obtained through the monitoring of the compressor suction pressure sensor; similarly, the current exhaust pressure of the compressor at the current temperature in the chamber can be obtained through the monitoring of the compressor exhaust pressure sensor, thereby determining the current state of the controlled environmental test chamber.

[0067] S120, obtaining linear temperature reduction parameters of the controlled environment test box, and determining a linear temperature reduction rate.

[0068] For example, the linear cooling parameters may include parameters such as the starting temperature, the ending temperature, and the cooling time of the total linear cooling process inside the controlled environment test box. Each linear cooling parameter may be set according to the test needs, and is not limited here. Based on the obtained set linear cooling parameters, the linear cooling rate of the linear cooling process in the controlled environment test box may be calculated.

[0069] S130, respectively calculating the compressor speed, the electronic expansion valve opening, the evaporator fan speed, and the condenser fan speed of the controlled environment test box according to the current state parameters, the linear cooling parameters, and the linear cooling rate.

[0070] Specifically, according to the acquired current state parameters, linear cooling parameters and linear cooling rate, the corresponding compressor speed formula, electronic expansion valve opening formula, evaporator fan speed formula and condenser fan speed formula can be used to accurately calculate the corresponding compressor speed, electronic expansion valve opening, evaporator fan speed and condenser fan speed when the controlled environmental test chamber is at the corresponding box temperature.

[0071] S140, based on the compressor speed, the electronic expansion valve opening, the evaporator fan speed and the condenser fan speed, respectively control the actions of the compressor, the electronic expansion valve, the evaporator fan and the condenser fan of the controlled environmental test chamber to achieve linear temperature reduction control of the controlled environmental test chamber.

[0072] Specifically, according to the obtained accurate compressor speed and electronic expansion valve opening, the compressor and the electronic expansion valve of the refrigeration system in the controlled environment test box are controlled, so that the refrigeration capacity of the compressor can be matched with the refrigeration capacity required during the linear cooling process, which is beneficial to reducing the energy consumption of the refrigeration system in the controlled environment test box. And according to the accurately calculated evaporator fan speed and condenser fan speed, the speed of the evaporator fan and the condenser fan at the corresponding box temperature is controlled, so that when the evaporator and the condenser operate normally during the linear cooling process, the evaporator fan and the condenser fan can respectively ensure that the temperature of the evaporator and the condenser is kept within a reasonable range, thereby reducing the operating energy consumption of the evaporator fan and the condenser fan to a certain extent, and is beneficial to improving the reliability of the refrigeration system operation.

[0073] The linear cooling control method of the environmental test box provided by the embodiment of the present invention obtains the current state parameters of the environmental test box to be controlled, obtains the pre-set linear cooling parameters of the environmental test box to be controlled, and determines the linear cooling rate. According to the obtained current state parameters, linear cooling parameters and linear cooling rate, the compressor speed, electronic expansion valve opening, evaporator fan speed and condenser fan speed of the environmental test box to be controlled are accurately calculated. According to the calculated accurate compressor speed and electronic expansion valve opening, the compressor and electronic expansion valve of the refrigeration system in the environmental test box to be controlled are controlled, so that the refrigeration capacity of the compressor can be matched with the refrigeration capacity required in the linear cooling process, which is beneficial to reducing the energy consumption of the refrigeration system. According to the calculated accurate evaporator fan speed and condenser fan speed, the evaporator fan and condenser fan are controlled. When the evaporator and condenser operate normally during the linear cooling process, their own temperatures can be kept in a reasonable range, thereby helping to reduce the operating energy consumption of the evaporator fan and the condenser fan, and improve the reliability of the operation of the refrigeration system.

[0074] Optionally, Figure 2 The following is a schematic diagram of a specific flow chart of step S130 in a linear temperature reduction control method for an environmental test chamber provided in an embodiment of the present invention. Figure 2 As shown, step S130 calculates the compressor speed, electronic expansion valve opening, evaporator fan speed and condenser fan speed of the controlled environment test box according to the current state parameters, linear cooling parameters and linear cooling rate, and specifically includes the following steps:

[0075] S131. Calculate the compressor speed according to the current temperature in the box, the current exhaust pressure of the compressor, the linear cooling parameter and the linear cooling rate.

[0076] Among them, based on the current temperature in the box, the current exhaust pressure of the compressor, the starting temperature, the ending temperature, the linear cooling rate and the cooling time, the compressor speed can be calculated according to the compressor speed formula.

[0077] Specifically, the compressor speed formula is expressed as:

[0078]

[0079] Among them, F min is the minimum speed of the compressor; F max is the maximum speed of the compressor; V is the linear cooling rate; τ is the cooling time; T0 is the starting temperature; T is the current temperature in the box; T sv is the final temperature; HP is the current exhaust pressure of the compressor; HP F0 The reference exhaust pressure for compressor speed control; a F , b F 、cF Both are equity coefficients.

[0080] It should be noted that the compressor speed formula expresses the relationship between the compressor speed and the current temperature in the box. In the process of linear cooling at the calculated linear cooling rate, the current temperature in the box gradually decreases from the starting temperature, and after the current temperature in the box is determined, the cooling time of the current linear cooling process can be obtained. Among them, the minimum compressor speed and the maximum compressor speed can be determined according to the model of the compressor used; the compressor speed control reference exhaust pressure is a pre-set known quantity; various equity coefficients can be set according to the needs of the actual test, and there is no restriction here. When the current temperature in the box drops to a certain temperature value, a corresponding compressor speed will be calculated, and the compressor action in the refrigeration system will be controlled according to the compressor speed, so that the compressor cooling capacity matches the cooling capacity required by the linear cooling process, which is beneficial to reduce the energy consumption of the refrigeration system.

[0081] S132. Calculate the opening of the electronic expansion valve according to the current state parameters, the compressor speed, the linear cooling parameters and the linear cooling rate.

[0082] Among them, based on the acquired current state parameters, starting temperature, ending temperature, linear cooling rate and cooling time, and the calculated compressor speed, the electronic expansion valve opening can be calculated using the electronic expansion valve opening formula.

[0083] Specifically, the electronic expansion valve opening formula is expressed as:

[0084]

[0085] Among them, E min E is the minimum opening of the electronic expansion valve; max is the maximum opening of the electronic expansion valve; V is the linear cooling rate; τ is the cooling time; T0 is the starting temperature; T is the current temperature in the box; T sv is the final temperature; HP is the current exhaust pressure of the compressor; LP is the current suction pressure of the compressor; F is the compressor speed; F max is the maximum speed of the compressor; a E 、b E 、c E ,d E Both are equity coefficients.

[0086] The electronic expansion valve opening formula shows the relationship between the electronic expansion valve opening and the current temperature in the box. Among them, the minimum opening of the electronic expansion valve and the maximum opening of the electronic expansion valve in the electronic expansion valve opening formula can be determined according to the electronic expansion valve model used; each equity coefficient can be set according to the needs of the actual test, and there is no restriction here. In the process of linear cooling at a linear cooling rate, when the current temperature in the box drops to a certain temperature value, a corresponding electronic expansion valve opening will be calculated.

[0087] S133. Calculate the evaporator fan speed according to the electronic expansion valve opening, the compressor speed, the current compressor suction pressure and the linear temperature reduction parameter.

[0088] Among them, based on the obtained current suction pressure, starting temperature, and ending temperature of the compressor, as well as the calculated electronic expansion valve opening and compressor speed, the evaporator fan speed formula can be used to calculate the evaporator fan speed.

[0089] Specifically, the evaporator fan speed formula is expressed as:

[0090]

[0091] Among them, A min is the minimum speed of the evaporator; A max is the maximum speed of the evaporator; E is the opening of the electronic expansion valve; E max is the maximum opening of the electronic expansion valve; T0 is the starting temperature; T is the current temperature in the box; T sv is the final temperature; LP is the current suction pressure of the compressor; LP A0 is the reference suction pressure for evaporator fan speed control; F is the compressor speed; F max is the maximum speed of the compressor; a A 、b A 、c A Both are equity coefficients.

[0092] It should be noted that the evaporator fan speed formula expresses the relationship between the evaporator fan speed and the current temperature in the box. Among them, the evaporator minimum speed and the evaporator maximum speed in the evaporator fan speed formula can be determined according to the model of the evaporator used; the evaporator fan speed control reference suction pressure is a pre-set known quantity; various equity coefficients can be set according to the needs of the actual test, and there is no restriction here. In the process of linear cooling at the calculated linear cooling rate, when the current temperature in the box drops to a certain temperature value, a corresponding evaporator fan speed will be calculated.

[0093] S134. Calculate the condenser fan speed according to the compressor speed and the current exhaust pressure of the compressor.

[0094] Among them, based on the acquired current exhaust pressure of the compressor and the calculated compressor speed, the condenser fan speed can be calculated according to the condenser fan speed formula.

[0095] Specifically, the condenser fan speed formula is expressed as:

[0096]

[0097] Among them, C min is the minimum speed of the condenser; C max is the maximum speed of the condenser; F is the speed of the compressor; F max is the maximum speed of the compressor; HP is the current exhaust pressure of the compressor; HP C0 The reference exhaust pressure for condenser fan speed control; a C , b C Both are equity coefficients.

[0098] It should be noted that the condenser fan speed represents the relationship between the condenser fan speed and the compressor speed. Among them, the minimum condenser speed and the maximum condenser speed in the condenser fan speed formula can be determined according to the condenser model used; the reference exhaust pressure of the condenser fan speed control is a pre-set known quantity; various equity coefficients can be set according to the needs of the actual test, and there is no restriction here. In the process of linear cooling at a linear cooling rate, when the current temperature in the box drops to a certain temperature value, according to the calculated corresponding compressor speed, a corresponding condenser fan speed can also be calculated accordingly. Based on the accurately calculated evaporator fan speed and condenser fan speed, the temperature of the evaporator and condenser can be kept within a reasonable range while ensuring the normal operation of the evaporator and condenser, thereby reducing the operating energy consumption of the evaporator fan and condenser fan, while improving the reliability of the refrigeration system operation.

[0099] Optionally, Figure 3 The specific flow chart of step S120 in the linear cooling control method of an environmental test chamber provided by an embodiment of the present invention is as follows. Based on the above embodiments, the linear cooling parameters include the starting temperature, the ending temperature and the total cooling time; Figure 3 As shown, determining the linear cooling rate in step S120 specifically includes the following steps:

[0100] S121. Subtract the final temperature from the initial temperature to determine the temperature change value.

[0101] Specifically, before performing linear cooling control, the starting temperature, ending temperature and total cooling time of the linear cooling process inside the controlled environmental test chamber are preset. The temperature change value of the complete linear cooling process can be obtained by subtracting the ending temperature from the starting temperature. It should be noted that since the temperature inside the controlled environmental test chamber is gradually reduced during the linear cooling process, the ending temperature is less than the starting temperature. Using the method of subtracting the starting temperature from the ending temperature, the calculated change value is a negative value, and the absolute value of the negative value can be taken to determine the temperature change value; or, using the method of subtracting the ending temperature from the starting temperature, the calculated change value is a positive value, which can be directly determined as the temperature change value.

[0102] S122. Divide the temperature change value by the total cooling time to determine the linear cooling rate.

[0103] Specifically, the calculated temperature change value is divided by the total cooling time to obtain the linear cooling rate that remains unchanged during the complete linear cooling process. For example, the linear cooling rate can be obtained by the formula V=(T0-T sv ) / t. Where V is the linear cooling rate; t is the total cooling time; T0 is the starting temperature; T sv The final temperature.

[0104] An embodiment of the present invention further provides an environmental test box. The environmental test box includes: a box body, a control system and a refrigeration system; the refrigeration system is arranged in the box body. The control system is used to execute the linear temperature reduction control method of the environmental test box provided in any of the above embodiments to control the action of the refrigeration system, and has similar beneficial effects as the linear temperature reduction control method of the environmental test box provided in any of the above embodiments of the present invention, which will not be described in detail here.

[0105] Optionally, Figure 4 The following is a schematic diagram of the structure of an environmental test chamber provided by an embodiment of the present invention. Figure 4 As shown, the refrigeration system includes a compressor 10 , an electronic expansion valve 11 , a condenser 12 , a condenser fan 13 , an evaporator 14 and an evaporator fan 15 .

[0106] The compressor 10 , the condenser 12 , the electronic expansion valve 11 and the evaporator 14 are connected in series in sequence to form a loop. The condenser fan 13 is arranged at the condenser 12 , and the evaporator fan 15 is arranged at the evaporator 14 .

[0107] The control system includes a display unit, a data acquisition unit 21 and a control unit 22 .

[0108] The display unit is arranged on the surface of the box, the data acquisition unit 21 is arranged inside the box, and the display unit and the data acquisition unit 21 are electrically connected to the control unit 22 respectively; the data acquisition unit 21 includes a temperature sensor 211, a compressor suction pressure sensor 212 and a compressor exhaust pressure sensor 213; the temperature sensor 211 is arranged inside the box, the compressor suction pressure sensor 212 is arranged at the suction port of the compressor 10, and the compressor exhaust pressure sensor 213 is arranged at the exhaust port of the compressor 10.

[0109] The control unit 22 includes an acquisition and calculation control module 221, a compressor speed control module 222, an electronic expansion valve opening control module 223, an evaporator fan speed control module 224 and a condenser fan speed control module 225; the acquisition and calculation control module 221 is electrically connected to the sensor in the data acquisition unit 21, as well as the compressor speed control module 222, the electronic expansion valve opening control module 223, the evaporator fan speed control module 224, and the condenser fan speed control module 225; the compressor speed control module 222 is electrically connected to the compressor 10; the electronic expansion valve opening control module 223 is electrically connected to the electronic expansion valve 11; the evaporator fan speed control module 224 is electrically connected to the evaporator fan 15; and the condenser fan speed control module 225 is electrically connected to the condenser fan 13.

[0110] Specifically, the box body material of the environmental test box can be made of heat-insulating materials; the display unit can be set on the surface of the box body, and for example, the display unit can include a touch screen; the compressor uses a variable frequency compressor. The acquisition calculation control module 221 and the sensors in the data acquisition unit 21 can be connected through wireless communication. Therefore, in order to make Figure 4 It is convenient to clearly show the connection structure inside the environmental test chamber. Figure 4 The electrical connection lines between the acquisition calculation control module 221 and each sensor are not shown.

[0111] The acquisition calculation control module 221 is used to calculate the compressor speed, electronic expansion valve opening, evaporator fan speed and condenser fan speed of the environmental test box according to the current temperature in the box, the current suction pressure of the compressor and the current exhaust pressure of the compressor, as well as the linear cooling parameters and the linear cooling rate. According to the calculated compressor speed, electronic expansion valve opening, evaporator fan speed and condenser fan speed, corresponding control signals are generated for the compressor 10, the electronic expansion valve 11, the evaporator fan 15 and the condenser fan 13, and the speed control signal of the compressor 10 is output to the compressor speed control module 222, the opening control signal of the electronic expansion valve 11 is output to the electronic expansion valve opening control module 223, the evaporator fan speed control signal is output to the evaporator fan speed control module 224, and the condenser fan speed control signal is output to the condenser fan speed control module 225, so as to control the compressor 10, the electronic expansion valve 11, the evaporator fan 15 and the condenser fan 13 to perform corresponding actions, realize linear cooling optimization control of the environmental test chamber, reduce the energy consumption of the refrigeration system, reduce the operating energy consumption of the evaporator fan 15 and the condenser fan 13, and improve the reliability of the operation of the refrigeration system.

[0112] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A linear temperature reduction control method for an environmental test chamber, characterized in that: include: Obtaining current state parameters of the controlled environment test box; wherein the current state parameters include the current temperature in the box, the current suction pressure of the compressor, and the current exhaust pressure of the compressor; Obtaining the linear cooling parameters of the controlled environment test box and determining the linear cooling rate; According to the current state parameter, the linear temperature drop parameter and the linear temperature drop rate, respectively calculating the compressor speed, the electronic expansion valve opening, the evaporator fan speed and the condenser fan speed of the controlled environment test box; Based on the compressor speed, the electronic expansion valve opening, the evaporator fan speed and the condenser fan speed, the compressor, electronic expansion valve, evaporator fan and condenser fan of the controlled environmental test box are controlled respectively to achieve linear temperature reduction control of the controlled environmental test box.

2. The linear temperature reduction control method of the environmental test chamber according to claim 1, characterized in that: The method of calculating the compressor speed, the electronic expansion valve opening, the evaporator fan speed and the condenser fan speed of the controlled environment test box according to the current state parameter, the linear cooling parameter and the linear cooling rate includes: Calculating the compressor speed according to the current temperature in the box, the current exhaust pressure of the compressor, the linear temperature reduction parameter and the linear temperature reduction rate; Calculating the opening of the electronic expansion valve according to the current state parameter, the compressor speed, the linear temperature drop parameter and the linear temperature drop rate; Calculating the evaporator fan speed according to the electronic expansion valve opening, the compressor speed, the current suction pressure of the compressor and the linear temperature reduction parameter; The condenser fan speed is calculated according to the compressor speed and the current exhaust pressure of the compressor.

3. The linear temperature reduction control method of the environmental test chamber according to claim 2, characterized in that: The linear cooling parameters include starting temperature, ending temperature and total cooling time; The calculating the compressor speed according to the current temperature in the box, the current exhaust pressure of the compressor, the linear temperature reduction parameter and the linear temperature reduction rate includes: Calculating the compressor speed using a compressor speed formula according to the current temperature in the box, the current exhaust pressure of the compressor, the starting temperature, the ending temperature, the linear cooling rate and the cooling time; The compressor speed formula is expressed as: Among them, F min is the minimum speed of the compressor; F max is the maximum speed of the compressor; V is the linear cooling rate; τ is the cooling time; T0 is the starting temperature; T is the current temperature in the box; T sv is the final temperature; HP is the current exhaust pressure of the compressor; HP F0 The reference exhaust pressure for compressor speed control; a F 、b F 、c F Both are equity coefficients.

4. The linear temperature reduction control method of the environmental test chamber according to claim 2, characterized in that: The linear cooling parameters include starting temperature, ending temperature and total cooling time; The calculating the opening of the electronic expansion valve according to the current state parameter, the compressor speed, the linear temperature drop parameter and the linear temperature drop rate comprises: Calculating the electronic expansion valve opening degree using an electronic expansion valve opening degree formula according to the current state parameter, the compressor speed, the starting temperature, the ending temperature, the linear cooling rate and the cooling time; The electronic expansion valve opening formula is expressed as: Among them, E min E is the minimum opening of the electronic expansion valve; max is the maximum opening of the electronic expansion valve; V is the linear cooling rate; τ is the cooling time; T0 is the starting temperature; T is the current temperature in the box; T sv is the final temperature; HP is the current exhaust pressure of the compressor; LP is the current suction pressure of the compressor; F is the compressor speed; F max is the maximum speed of the compressor; a E 、b E 、c E ,d E Both are equity coefficients.

5. The linear temperature reduction control method of the environmental test chamber according to claim 2, characterized in that: The linear cooling parameters include starting temperature, ending temperature and total cooling time; The step of calculating the evaporator fan speed according to the electronic expansion valve opening, the compressor speed, the current suction pressure of the compressor and the linear temperature reduction parameter comprises: Calculating the evaporator fan speed using an evaporator fan speed formula according to the electronic expansion valve opening, the compressor speed, the current suction pressure of the compressor, the starting temperature and the ending temperature; The evaporator fan speed formula is expressed as: Among them, A min is the minimum speed of the evaporator; A max is the maximum speed of the evaporator; E is the opening of the electronic expansion valve; E max is the maximum opening of the electronic expansion valve; T0 is the starting temperature; T is the current temperature in the box; T sv is the final temperature; LP is the current suction pressure of the compressor; LP A0 is the reference suction pressure for evaporator fan speed control; F is the compressor speed; F max is the maximum speed of the compressor; a A 、b A 、c A Both are equity coefficients.

6. The linear temperature reduction control method of the environmental test chamber according to claim 2, characterized in that: The step of calculating the condenser fan speed according to the compressor speed and the current exhaust pressure of the compressor includes: Calculating the condenser fan speed using a condenser fan speed formula according to the compressor speed and the current exhaust pressure of the compressor; The condenser fan speed formula is expressed as: Among them, C min is the minimum speed of the condenser; C max is the maximum speed of the condenser; F is the speed of the compressor; F max is the maximum speed of the compressor; HP is the current exhaust pressure of the compressor; HP C0 The reference exhaust pressure for condenser fan speed control; a C 、b C Both are equity coefficients.

7. The linear temperature reduction control method of the environmental test chamber according to claim 1, characterized in that: The linear cooling parameters include starting temperature, ending temperature and total cooling time; Determining the linear cooling rate includes: Subtract the final temperature from the starting temperature to determine a temperature change value; The linear cooling rate is determined by dividing the temperature change value by the total cooling time.

8. An environmental test chamber, characterized in that: include: A box, a control system and a refrigeration system; the refrigeration system is arranged in the box; The control system is used to execute the linear temperature reduction control method of the environmental test box as described in any one of claims 1 to 7 to control the operation of the refrigeration system.

9. The environmental test chamber according to claim 8, characterized in that: The refrigeration system includes a compressor, an electronic expansion valve, a condenser, a condenser fan, an evaporator and an evaporator fan; The compressor, the condenser, the electronic expansion valve and the evaporator are connected in series in sequence to form a loop, the condenser fan is arranged at the condenser, and the evaporator fan is arranged at the evaporator.

10. The environmental test chamber according to claim 9, characterized in that: The control system includes a display unit, a data acquisition unit and a control unit; The display unit is arranged on the surface of the box, the data acquisition unit is arranged inside the box, and the display unit and the data acquisition unit are electrically connected to the control unit respectively; The data acquisition unit includes a temperature sensor, a compressor suction pressure sensor and a compressor exhaust pressure sensor; the temperature sensor is arranged inside the box, the compressor suction pressure sensor is arranged at the suction port of the compressor, and the compressor exhaust pressure sensor is arranged at the exhaust port of the compressor; The control unit includes an acquisition and calculation control module, a compressor speed control module, an electronic expansion valve opening control module, an evaporator fan speed control module and a condenser fan speed control module; The acquisition calculation control module is electrically connected to the sensor in the data acquisition unit, the compressor speed control module, the electronic expansion valve opening control module, the evaporator fan speed control module, and the condenser fan speed control module; The compressor speed control module is electrically connected to the compressor; The electronic expansion valve opening control module is electrically connected to the electronic expansion valve; The evaporator fan speed control module is electrically connected to the evaporator fan; The condenser fan speed control module is electrically connected to the condenser fan.

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