Linear cooling control method of environmental test box and environmental test box

Abstract

The invention discloses a linear cooling control method of an environmental test box and the environmental test box. The method comprises the following steps: acquiring the temperature in a to-be-controlled environment test box, the suction pressure of a variable-frequency compressor and the exhaust pressure of the variable-frequency compressor; calculating the linear cooling rate of the to-be-controlled environment test box based on the preset temperature parameter; according to the temperature in the box, the suction pressure of the inverter compressor, the exhaust pressure of the inverter compressor and the linear cooling rate, a database is obtained, and the target rotating speed of the inverter compressor, the target opening degree of an electronic expansion valve, the target rotating speed of an evaporator fan and the target rotating speed of a condenser fan of the to-be-controlled environment test box are calculated based on the database; and based on the calculated target rotating speed of the inverter compressor, the target opening degree of the electronic expansion valve, the target rotating speed of the evaporator fan and the target rotating speed of the condenser fan, the inverter compressor, the electronic expansion valve, the evaporator fan and the condenser fan of the to-be-controlled environment test box are controlled to act, so that linear cooling control over the to-be-controlled environment test box is achieved.

Description

Technical Field

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

[0002] With the continuous improvement of life and technology, the requirements for product reliability are getting higher and higher. In many fields, it is necessary to test the reliability, material stress changes, and material property changes of products or components in the process of cooling from high temperature to low temperature in a certain period of time. In the linear cooling process, as the temperature drops, the demand for cooling capacity will increase. In addition, as the temperature decreases, the evaporation temperature also needs to be lowered. When the condensing temperature is constant, the cooling capacity of the compressor will decrease as the evaporation temperature decreases. Therefore, the compressor capacity exerted from the beginning to the end of linear cooling varies greatly.

[0003] At present, fixed-frequency compressors are mostly used for linear cooling. The compressor is selected according to the maximum cooling capacity requirement of the linear cooling process, which 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 very important. If 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.

[0004] Therefore, optimizing system control and operation during the linear cooling process is crucial to improving system operation reliability and reducing system operation energy consumption. Summary of the invention

[0005] The invention provides a linear temperature reduction control method of an environmental test box and the environmental test box, so as to solve the problem that the existing linear temperature reduction control method of the environmental test box has poor energy saving performance.

[0006] According to one aspect of the present invention, a linear temperature reduction control method for an environmental test chamber is provided, comprising:

[0007] Obtain the temperature inside the controlled environment test chamber, the suction pressure of the variable frequency compressor, and the exhaust pressure of the variable frequency compressor;

[0008] Calculating the linear cooling rate of the controlled environment test box based on preset temperature parameters;

[0009] According to the temperature in the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear temperature reduction rate, a database is obtained, and based on the database, a target speed of the variable frequency compressor, a target opening of the electronic expansion valve, a target speed of the evaporator fan and a target speed of the condenser fan of the controlled environmental test box are calculated respectively;

[0010] Based on the calculated target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan, the operations of the variable frequency compressor, the electronic expansion valve, the evaporator fan and the condenser fan of the environmental test box to be controlled respectively, so as to realize linear temperature reduction control of the environmental test box to be controlled.

[0011] Optionally, the database is obtained according to the temperature inside the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate, and the variable frequency compressor target speed, the electronic expansion valve target opening, the evaporator fan target speed and the condenser fan target speed of the controlled environmental test box are calculated based on the database, including:

[0012] Obtaining a first database according to the temperature in the box and the linear cooling rate;

[0013] Determine the initial speed of the variable frequency compressor according to the first database;

[0014] Obtaining a second database according to the variable frequency compressor suction pressure and the variable frequency compressor exhaust pressure;

[0015] determining a modified speed of the variable frequency compressor according to the second database;

[0016] The target speed of the variable frequency compressor of the controlled environment test box is calculated according to the initial speed of the variable frequency compressor and the corrected speed of the variable frequency compressor.

[0017] Optionally, the step of obtaining a database according to the temperature in the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate, and respectively calculating the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan of the controlled environmental test box based on the database further includes:

[0018] Obtaining a third database according to the variable frequency compressor target speed and the linear temperature reduction rate;

[0019] Determining the initial opening of the electronic expansion valve according to the third database;

[0020] Obtaining a fourth database according to the temperature in the box and the compression ratio of the variable frequency compressor calculated by the suction pressure of the variable frequency compressor and the exhaust pressure of the variable frequency compressor;

[0021] determining a corrected opening degree of the electronic expansion valve according to the fourth database;

[0022] The target opening of the electronic expansion valve is calculated according to the initial opening of the electronic expansion valve and the corrected opening of the electronic expansion valve.

[0023] Optionally, the step of obtaining a database according to the temperature in the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate, and respectively calculating the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan of the controlled environmental test box based on the database further includes:

[0024] obtaining a fifth database according to the target opening of the electronic expansion valve and the target speed of the variable frequency compressor;

[0025] determining an initial speed of the evaporator fan according to the fifth database;

[0026] A sixth database is obtained according to the temperature in the box and the suction pressure of the variable frequency compressor;

[0027] determining a corrected speed of the evaporator fan according to the sixth database;

[0028] The evaporator fan target speed is calculated according to the evaporator fan initial speed and the evaporator fan corrected speed.

[0029] Optionally, the step of obtaining a database according to the temperature in the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate, and respectively calculating the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan of the controlled environmental test box based on the database further includes:

[0030] Obtaining a seventh database according to the target speed of the variable frequency compressor and the exhaust pressure of the variable frequency compressor;

[0031] The target speed of the condenser fan is determined according to the seventh database.

[0032] Optionally, the calculating the target speed of the variable frequency compressor of the controlled environment test box according to the initial speed of the variable frequency compressor and the corrected speed of the variable frequency compressor includes:

[0033] The sum of the initial speed of the variable frequency compressor and the corrected speed of the variable frequency compressor is determined as the target speed of the variable frequency compressor of the controlled environment test box.

[0034] Optionally, the calculating the target opening of the electronic expansion valve according to the initial opening of the electronic expansion valve and the corrected opening of the electronic expansion valve includes:

[0035] The sum of the initial opening of the electronic expansion valve and the corrected opening of the electronic expansion valve is determined as the target opening of the electronic expansion valve.

[0036] Optionally, the calculating the target speed of the evaporator fan according to the initial speed of the evaporator fan and the corrected speed of the evaporator fan includes:

[0037] The sum of the initial speed of the evaporator fan and the corrected speed of the evaporator fan is determined as the target speed of the evaporator fan.

[0038] According to another aspect of the present invention, an environmental test chamber is provided, the environmental test chamber comprising a chamber body, a control system and a refrigeration system, the control system executing the linear temperature reduction control method of the environmental test chamber according to any one of claims 1 to 8 above;

[0039] The control system comprises a display unit, a sensor unit and a control unit, wherein the sensor unit is arranged in the box, the display unit is arranged on the surface of the box, the control unit is arranged in the box or outside the box, and the display unit and the sensor unit are electrically connected to the control unit respectively;

[0040] The refrigeration system is arranged in the box, and includes a variable frequency compressor, a condenser, a condenser fan, an evaporator, an evaporator fan, and an electronic expansion valve; the evaporator, the electronic expansion valve, the condenser and the variable frequency compressor are connected in series to form a loop.

[0041] Optionally, the sensor unit includes an in-box temperature sensor, a variable frequency compressor suction pressure sensor, and a variable frequency compressor exhaust pressure sensor; the variable frequency compressor suction pressure sensor and the variable frequency compressor exhaust pressure sensor are respectively arranged at the inlet and outlet of the variable frequency compressor;

[0042] The control unit includes an evaporator fan speed control module, a variable frequency compressor speed control module, an electronic expansion valve opening control module, a condenser fan speed control module, and a collection and calculation control module;

[0043] The acquisition and calculation control module is electrically connected to the temperature sensor in the box; the electronic expansion valve opening control module is electrically connected to the electronic expansion valve; the variable frequency compressor speed control module is electrically connected to the variable frequency compressor; the condenser fan speed control module is electrically connected to the condenser fan; the evaporator fan speed control module is electrically connected to the evaporator fan.

[0044] The technical solution provided by the embodiment of the present invention can effectively reduce the energy consumption of the system and improve energy saving by accurately calculating the target speed of the variable frequency compressor, so that the compressor cooling capacity is matched with the required cooling capacity; by accurately calculating the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan, the system operation reliability is effectively improved while reducing the energy consumption of the fan, and the problem of poor energy saving of the existing linear cooling control method of the environmental test chamber is solved.

[0045] 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

[0046] 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.

[0047] Figure 1 A flow chart of a linear temperature reduction control method for an environmental test chamber provided by an embodiment of the present invention;

[0048] Figure 2 A schematic structural diagram of an environmental test chamber provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] 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.

[0050] 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.

[0051] Figure 1 A flow chart of a linear temperature reduction control method for an environmental test chamber provided in an embodiment of the present invention, see Figure 1 , the linear temperature reduction control method comprises:

[0052] S110, obtaining the temperature inside the controlled environment test box, the suction pressure of the variable frequency compressor, and the exhaust pressure of the variable frequency compressor.

[0053] Among them, the 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 environmental test chamber can simulate a variety of environmental factors, such as temperature, humidity, air pressure, light, vibration, etc. By placing the product or material in the test chamber and testing it under set environmental conditions for a period of time, we can understand the situation that the product may face in the actual use environment, so as to improve and optimize the product.

[0054] Specifically, an internal temperature sensor, a variable frequency compressor suction pressure sensor and a variable frequency compressor exhaust pressure sensor are provided in the controlled environmental test box. The internal temperature sensor, the variable frequency compressor suction pressure sensor and the variable frequency compressor exhaust pressure sensor in the controlled environmental test box can be used to obtain the internal temperature of the controlled environmental test box, the variable frequency compressor suction pressure and the variable frequency compressor exhaust pressure respectively.

[0055] S120, calculating the linear cooling rate of the controlled environment test box based on the preset temperature parameters.

[0056] The preset temperature parameters may be preset according to the test requirements, and the preset temperature parameters include at least one of the following: a starting temperature, an ending temperature, and a total cooling time.

[0057] Specifically, the difference between the starting temperature and the ending temperature is calculated, and the ratio of the difference to the total cooling time is determined as the linear cooling rate of the controlled environment test box.

[0058] S130. Obtain a database according to the temperature inside the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor, and the linear cooling rate, and calculate the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan of the controlled environmental test box based on the database.

[0059] Specifically, a database is obtained according to the temperature inside the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate. The initial speed and the corrected speed of the variable frequency compressor, the initial opening and the corrected opening of the electronic expansion valve, the initial speed and the corrected speed of the evaporator fan, and the target speed of the condenser fan are determined based on the database. According to the initial speed and the corrected speed of the variable frequency compressor, the initial opening and the corrected opening of the electronic expansion valve, and the initial speed and the corrected speed of the evaporator fan, the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, and the target speed of the evaporator fan of the controlled environmental test box are calculated respectively.

[0060] S140, based on the calculated target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan, respectively control the actions of the variable frequency compressor, the electronic expansion valve, the evaporator fan and the condenser fan of the controlled environmental test box to achieve linear temperature reduction control of the controlled environmental test box.

[0061] Specifically, the calculated target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan are used to control the variable frequency compressor, the electronic expansion valve, the evaporator fan and the condenser fan of the controlled environmental test box to achieve linear cooling control of the controlled environmental test box. Since the linear cooling rate is involved in the process of calculating the target speed of the variable frequency compressor, and the linear cooling rate can characterize the cooling capacity, the target speed of the variable frequency compressor is further calculated based on the linear cooling rate, and the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan are all based on the target speed of the variable frequency compressor. Therefore, based on the calculated target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan, the actions of the variable frequency compressor, the electronic expansion valve, the evaporator fan and the condenser fan of the controlled environmental test box are respectively controlled, thereby realizing stable linear cooling control of the controlled environmental test box. At the same time, the target speed of the variable frequency compressor, the target speed of the evaporator fan and the target speed of the condenser fan all change according to the change of the cooling capacity demand, effectively reducing the energy consumption of the compressor and the fan on the basis of ensuring the reliability of the system.

[0062] The technical solution provided by the embodiment of the present invention can effectively reduce the energy consumption of the system and improve energy saving by accurately calculating the target speed of the variable frequency compressor, so that the compressor cooling capacity is matched with the required cooling capacity; by accurately calculating the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan, the system operation reliability is effectively improved while reducing the energy consumption of the fan, and the problem of poor energy saving of the existing linear cooling control method of the environmental test chamber is solved.

[0063] Optionally, a database is obtained according to the temperature inside the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor, and the linear cooling rate, and the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan of the controlled environmental test box are calculated based on the database, including:

[0064] A first database is obtained according to the temperature inside the box and the linear cooling rate; and an initial rotation speed of the variable frequency compressor is determined according to the first database.

[0065] Specifically, according to the temperature in the box and the linear cooling rate, a first database is obtained through experimental calibration, and the initial speed of the variable frequency compressor is determined according to the first database, as shown in Table 1 below.

[0066] Table 1

[0067]

[0068]

[0069] In Table 1, V is the linear cooling rate, T is the temperature inside the box, F0 is the initial speed of the variable frequency compressor, and i and j are both integers greater than 0.

[0070] A second database is obtained according to the suction pressure of the variable frequency compressor and the exhaust pressure of the variable frequency compressor; and a modified rotation speed of the variable frequency compressor is determined according to the second database.

[0071] Specifically, according to the suction pressure of the variable frequency compressor and the exhaust pressure of the variable frequency compressor, a second database is obtained through test calibration; and the modified speed of the variable frequency compressor is determined according to the second database.

[0072] Table 2

[0073] HP1 HP2 … HPj LP1 ΔF_11 ΔF_12 … ΔF_1j LP2 ΔF_21 ΔF_22 … ΔF_2j … … … … … LPi ΔF_i1 ΔF_i2 … ΔF_ij

[0074] In Table 2, HP is the exhaust pressure of the variable frequency compressor, LP is the suction pressure of the variable frequency compressor, and ΔF is the corrected speed of the variable frequency compressor.

[0075] According to the initial speed of the variable frequency compressor and the corrected speed of the variable frequency compressor, the target speed of the variable frequency compressor of the controlled environment test box is calculated.

[0076] Optionally, according to the initial speed of the variable frequency compressor and the corrected speed of the variable frequency compressor, calculating the target speed of the variable frequency compressor of the controlled environment test chamber includes:

[0077] The sum of the initial speed of the variable frequency compressor and the corrected speed of the variable frequency compressor is determined as the target speed of the variable frequency compressor of the controlled environment test box.

[0078] Specifically, the target speed of the variable frequency compressor of the controlled environment test box is calculated using the following formula:

[0079] F=F0+ΔF; wherein, F is the target speed of the variable frequency compressor, F0 is the initial speed of the variable frequency compressor, and ΔF is the corrected speed of the variable frequency compressor.

[0080] Optionally, a database is obtained according to the temperature inside the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor, and the linear cooling rate, and the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan of the controlled environmental test box are calculated based on the database, and the following is also included:

[0081] A third database is obtained according to the target speed of the variable frequency compressor and the linear temperature reduction rate; and an initial opening degree of the electronic expansion valve is determined according to the third database.

[0082] Specifically, according to the target speed of the variable frequency compressor and the linear cooling rate, a third database is obtained through experimental calibration, and the initial opening of the electronic expansion valve is determined according to the third database, as shown in Table 3 below.

[0083] Table 3

[0084] F1 F2 … Fj V1 E0_11 E0_12 … E0_1j V2 E0_21 E0_22 … E0_2j … … … … … Vi E0_i1 E0_i2 … E0_ij

[0085] In Table 3, V is the linear cooling rate, F is the target speed of the variable frequency compressor, and E0 is the initial opening of the electronic expansion valve.

[0086] The fourth database is obtained according to the temperature in the box and the compression ratio of the variable frequency compressor calculated by the suction pressure of the variable frequency compressor and the exhaust pressure of the variable frequency compressor; and the correction opening of the electronic expansion valve is determined according to the fourth database.

[0087] Specifically, according to the temperature inside the box and the compression ratio of the variable frequency compressor calculated by the suction pressure of the variable frequency compressor and the exhaust pressure of the variable frequency compressor, the fourth database is obtained through experimental calibration; the corrected opening of the electronic expansion valve is determined according to the fourth database, as shown in Table 4 below.

[0088] Table 4

[0089]

[0090]

[0091] In Table 4, T is the temperature inside the box, K is the compression ratio of the variable frequency compressor, K=HP / LP, LP is the suction pressure of the variable frequency compressor, HP is the exhaust pressure of the variable frequency compressor, and ΔE is the corrected opening of the electronic expansion valve.

[0092] The target opening of the electronic expansion valve is calculated according to the initial opening of the electronic expansion valve and the corrected opening of the electronic expansion valve.

[0093] Optionally, calculating the target opening of the electronic expansion valve according to the initial opening of the electronic expansion valve and the corrected opening of the electronic expansion valve includes:

[0094] The sum of the initial opening of the electronic expansion valve and the corrected opening of the electronic expansion valve is determined as the target opening of the electronic expansion valve.

[0095] Specifically, the target opening of the electronic expansion valve is calculated using the following formula:

[0096] E=E0+ΔE; wherein E is the target opening of the electronic expansion valve, E0 is the initial opening of the electronic expansion valve, and ΔE is the corrected opening of the electronic expansion valve.

[0097] Optionally, a database is obtained according to the temperature inside the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor, and the linear cooling rate, and the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan of the controlled environmental test box are calculated based on the database, and the following is also included:

[0098] A fifth database is obtained according to the target opening of the electronic expansion valve and the target speed of the variable frequency compressor; and an initial speed of the evaporator fan is determined according to the fifth database.

[0099] Specifically, according to the target opening of the electronic expansion valve and the target speed of the variable frequency compressor, a fifth database is obtained through experimental calibration; the initial speed of the evaporator fan is determined according to the fifth database, as shown in Table 5 below.

[0100] Table 5

[0101] F1 F2 … Fj E1 A0_11 A0_12 … A0_1j E2 A0_21 A0_22 … A0_2j … … … … … Ei A0_i1 A0_i2 … A0_ij

[0102] In Table 5, E is the target opening of the electronic expansion valve, F is the target speed of the variable frequency compressor, and A0 is the initial speed of the evaporator fan.

[0103] A sixth database is obtained according to the temperature inside the box and the suction pressure of the variable frequency compressor; and a corrected rotation speed of the evaporator fan is determined according to the sixth database.

[0104] Specifically, according to the temperature inside the box and the suction pressure of the variable frequency compressor, the sixth database is obtained through experimental calibration; the corrected speed of the evaporator fan is determined according to the sixth database, as shown in Table 6 below.

[0105] Table 6

[0106] LP1 LP2 … LPj T1 ΔA_11 ΔA_12 … ΔA_1j T2 ΔA_21 ΔA_22 … ΔA_2j … … … … … Ti ΔA_i1 ΔA_i2 … ΔA_ij

[0107] In Table 6, T is the temperature inside the box, LP is the suction pressure of the variable frequency compressor, and ΔA is the corrected speed of the evaporator fan.

[0108] The target speed of the evaporator fan is calculated according to the initial speed of the evaporator fan and the corrected speed of the evaporator fan.

[0109] Optionally, according to the evaporator fan initial speed and the evaporator fan correction speed, calculating the evaporator fan target speed includes:

[0110] The sum of the initial speed of the evaporator fan and the corrected speed of the evaporator fan is determined as the target speed of the evaporator fan.

[0111] Specifically, the evaporator fan target speed is calculated using the following formula:

[0112] A=A0+ΔA; wherein A is the target speed of the evaporator fan, A0 is the initial speed of the evaporator fan, and ΔA is the corrected speed of the evaporator fan.

[0113] Optionally, a database is obtained according to the temperature inside the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor, and the linear cooling rate, and the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan of the controlled environmental test box are calculated based on the database, and the following is also included:

[0114] A seventh database is obtained according to the target speed of the variable frequency compressor and the exhaust pressure of the variable frequency compressor; and a target speed of the condenser fan is determined according to the seventh database.

[0115] Specifically, according to the target speed of the variable frequency compressor and the exhaust pressure of the variable frequency compressor, the seventh database is obtained through experimental calibration; the target speed of the condenser fan is determined according to the seventh database, as shown in Table 7 below.

[0116] Table 7

[0117] F1 F2 … Fj HP1 C_11 C_12 … C_1j HP2 C_21 C_22 … C_2j … … … … … HPi C_i1 C_i2 … C_ij

[0118] In Table 7, C is the target speed of the condenser fan, F is the target speed of the variable frequency compressor, and HP is the exhaust pressure of the variable frequency compressor.

[0119] The technical solution provided by the embodiment of the present invention determines the database through the temperature inside the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate, and accurately calculates the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan based on the database, so that the compressor cooling capacity is matched with the required cooling capacity, effectively reducing the system energy consumption, improving the system operation reliability, and solving the problem of poor energy saving of the existing linear cooling control method of the environmental test box.

[0120] Figure 2 A schematic diagram of the structure of an environmental test chamber provided by an embodiment of the present invention, see Figure 2 The environmental test box includes a box body, a control system and a refrigeration system. The control system executes the linear temperature reduction control method of the environmental test box provided in any embodiment of the present invention.

[0121] The control system includes a display unit, a sensor unit and a control unit. The sensor unit is arranged in a box body, the display unit is arranged on a surface of the box body, the control unit is arranged in or outside the box body, and the display unit and the sensor unit are electrically connected to the control unit respectively.

[0122] The refrigeration system is arranged in the box, including a variable frequency compressor 2, a condenser 3, a condenser fan 4, an evaporator 6, an evaporator fan 7, and an electronic expansion valve 5; the evaporator 6, the electronic expansion valve 5, the condenser 3 and the variable frequency compressor 2 are connected in series to form a loop.

[0123] Optionally, the sensor unit includes an in-box temperature sensor 1, a variable frequency compressor suction pressure sensor 8, and a variable frequency compressor exhaust pressure sensor 9; the variable frequency compressor suction pressure sensor 8 and the variable frequency compressor exhaust pressure sensor 9 are respectively arranged at the inlet and outlet of the variable frequency compressor 2.

[0124] The control unit includes an evaporator fan speed control module 10 , a variable frequency compressor speed control module 11 , an electronic expansion valve opening control module 12 , a condenser fan speed control module 13 , and a collection and calculation control module 14 .

[0125] The acquisition and calculation control module 14 is electrically connected to the temperature sensor 1 in the box; the electronic expansion valve opening control module 12 is electrically connected to the electronic expansion valve 5; the variable frequency compressor speed control module 11 is electrically connected to the variable frequency compressor 2; the condenser fan speed control module 13 is electrically connected to the condenser fan 4; and the evaporator fan speed control module 10 is electrically connected to the evaporator fan 7.

[0126] Specifically, the acquisition calculation control module 14 is used to collect the temperature inside the controlled environmental test box, the suction pressure of the variable frequency compressor and the exhaust pressure of the variable frequency compressor, and calculate the linear cooling rate of the controlled environmental test box based on the preset temperature parameters. According to the temperature inside the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate, a database is obtained, and based on the database, the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan of the controlled environmental test box are calculated respectively; then, based on the calculated target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan The target speed of the condenser fan generates corresponding control instructions, and transmits the corresponding control instructions to the electronic expansion valve opening control module 12, the evaporator fan speed control module 10, the variable frequency compressor speed control module 11 and the condenser fan speed control module 13 respectively, so that the electronic expansion valve opening control module 12, the evaporator fan speed control module 10, the variable frequency compressor speed control module 11 and the condenser fan speed control module 13 respectively control the electronic expansion valve 5, the evaporator fan 7, the condenser fan 4 and the variable frequency compressor 2 of the environmental test box based on the control instructions to perform corresponding actions, thereby realizing linear temperature reduction control of the environmental test box.

[0127] The environmental test chamber provided in the embodiment of the present invention uses the linear temperature reduction control method of the environmental test chamber in the above embodiment. Therefore, the environmental test chamber provided in the embodiment of the present invention also has the beneficial effects described in the above embodiment, which will not be described in detail here.

[0128] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0129] 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: Obtain the temperature inside the controlled environment test chamber, the suction pressure of the variable frequency compressor, and the exhaust pressure of the variable frequency compressor; Calculating the linear cooling rate of the controlled environment test box based on preset temperature parameters; According to the temperature in the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear temperature reduction rate, a database is obtained, and based on the database, a target speed of the variable frequency compressor, a target opening of the electronic expansion valve, a target speed of the evaporator fan and a target speed of the condenser fan of the controlled environmental test box are calculated respectively; Based on the calculated target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan, the operations of the variable frequency compressor, the electronic expansion valve, the evaporator fan and the condenser fan of the environmental test box to be controlled respectively, so as to realize linear temperature reduction control of the environmental test box to be controlled.

2. The linear temperature reduction control method according to claim 1, characterized in that: The step of obtaining a database according to the temperature in the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate, and respectively calculating the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan of the controlled environmental test box based on the database includes: Obtaining a first database according to the temperature in the box and the linear cooling rate; Determine the initial speed of the variable frequency compressor according to the first database; Obtaining a second database according to the variable frequency compressor suction pressure and the variable frequency compressor exhaust pressure; determining a modified speed of the variable frequency compressor according to the second database; The target speed of the variable frequency compressor of the controlled environment test box is calculated according to the initial speed of the variable frequency compressor and the corrected speed of the variable frequency compressor.

3. The linear temperature reduction control method according to claim 2, characterized in that: The step of obtaining a database according to the temperature in the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate, and respectively calculating the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan of the controlled environmental test box based on the database further includes: Obtaining a third database according to the variable frequency compressor target speed and the linear temperature reduction rate; Determining the initial opening of the electronic expansion valve according to the third database; Obtaining a fourth database according to the temperature in the box and the compression ratio of the variable frequency compressor calculated by the suction pressure of the variable frequency compressor and the exhaust pressure of the variable frequency compressor; determining a corrected opening degree of the electronic expansion valve according to the fourth database; The target opening of the electronic expansion valve is calculated according to the initial opening of the electronic expansion valve and the corrected opening of the electronic expansion valve.

4. The linear temperature reduction control method according to claim 3, characterized in that: The step of obtaining a database according to the temperature in the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate, and respectively calculating the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan of the controlled environmental test box based on the database further includes: obtaining a fifth database according to the target opening of the electronic expansion valve and the target speed of the variable frequency compressor; determining an initial speed of the evaporator fan according to the fifth database; A sixth database is obtained according to the temperature in the box and the suction pressure of the variable frequency compressor; determining a corrected speed of the evaporator fan according to the sixth database; The evaporator fan target speed is calculated according to the evaporator fan initial speed and the evaporator fan corrected speed.

5. The linear temperature reduction control method according to claim 2, characterized in that: The step of obtaining a database according to the temperature in the box, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate, and respectively calculating the target speed of the variable frequency compressor, the target opening of the electronic expansion valve, the target speed of the evaporator fan and the target speed of the condenser fan of the controlled environmental test box based on the database further includes: Obtaining a seventh database according to the target speed of the variable frequency compressor and the exhaust pressure of the variable frequency compressor; The target speed of the condenser fan is determined according to the seventh database.

6. The linear temperature reduction control method according to claim 2, characterized in that: The calculating the target speed of the variable frequency compressor of the controlled environment test box according to the initial speed of the variable frequency compressor and the corrected speed of the variable frequency compressor comprises: The sum of the initial speed of the variable frequency compressor and the corrected speed of the variable frequency compressor is determined as the target speed of the variable frequency compressor of the controlled environment test box.

7. The linear temperature reduction control method according to claim 3, characterized in that: Calculating the target opening of the electronic expansion valve according to the initial opening of the electronic expansion valve and the corrected opening of the electronic expansion valve comprises: The sum of the initial opening of the electronic expansion valve and the corrected opening of the electronic expansion valve is determined as the target opening of the electronic expansion valve.

8. The linear temperature reduction control method according to claim 3, characterized in that: The calculating the target speed of the evaporator fan according to the initial speed of the evaporator fan and the corrected speed of the evaporator fan comprises: The sum of the initial speed of the evaporator fan and the corrected speed of the evaporator fan is determined as the target speed of the evaporator fan.

9. An environmental test chamber, characterized in that: The environmental test box includes a box body, a control system and a refrigeration system, and the control system executes the linear temperature reduction control method of the environmental test box according to any one of claims 1 to 8 above; The control system comprises a display unit, a sensor unit and a control unit, wherein the sensor unit is arranged in the box, the display unit is arranged on the surface of the box, the control unit is arranged in the box or outside the box, and the display unit and the sensor unit are electrically connected to the control unit respectively; The refrigeration system is arranged in the box, and includes a variable frequency compressor, a condenser, a condenser fan, an evaporator, an evaporator fan, and an electronic expansion valve; the evaporator, the electronic expansion valve, the condenser and the variable frequency compressor are connected in series in sequence to form a loop.

10. The environmental test chamber according to claim 9, characterized in that: The sensor unit includes an in-box temperature sensor, a variable frequency compressor suction pressure sensor, and a variable frequency compressor exhaust pressure sensor; the variable frequency compressor suction pressure sensor and the variable frequency compressor exhaust pressure sensor are respectively arranged at the inlet and outlet of the variable frequency compressor; The control unit includes an evaporator fan speed control module, a variable frequency compressor speed control module, an electronic expansion valve opening control module, a condenser fan speed control module, and a collection and calculation control module; The acquisition and calculation control module is electrically connected to the temperature sensor in the box; the electronic expansion valve opening control module is electrically connected to the electronic expansion valve; the variable frequency compressor speed control module is electrically connected to the variable frequency compressor; the condenser fan speed control module is electrically connected to the condenser fan; the evaporator fan speed control module is electrically connected to the evaporator fan.

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