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

Abstract

The application discloses a linear cooling control method of an environmental test chamber and the environmental test chamber. The method comprises the following steps: obtaining the temperature in the chamber, the suction pressure of a variable frequency compressor and the exhaust pressure of the variable frequency compressor of the environmental test chamber to be controlled; calculating the linear cooling rate of the environmental test chamber to be controlled based on preset temperature parameters; obtaining a database according to the temperature in the chamber, the suction pressure of the variable frequency compressor, the exhaust pressure of the variable frequency compressor and the linear cooling rate, and calculating the target rotating speed of the variable frequency 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 environmental test chamber to be controlled based on the database; and controlling the variable frequency compressor, the electronic expansion valve, the evaporator fan and the condenser fan of the environmental test chamber to be controlled based on the calculated target rotating speed of the variable frequency 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, so as to realize the linear cooling control of the environmental test chamber to be controlled.

Description

Technical Field

[0001] This invention relates to the field of environmental testing equipment control technology, and in particular to a linear cooling control method for an environmental test chamber and an environmental test chamber. Background Technology

[0002] With the continuous advancement of life and technology, the requirements for product reliability are becoming increasingly stringent. In many fields, it is necessary to test the reliability, material stress changes, and changes in material properties of products or components as they are cooled from high temperatures to low temperatures over a specific period. During linear cooling, the cooling capacity demand increases as the temperature decreases. Furthermore, as the temperature drops, the evaporation temperature also needs to decrease. When the condensation temperature is constant, the compressor's cooling capacity decreases as the evaporation temperature decreases. Therefore, the compressor's capacity varies significantly from the beginning to the end of a linear cooling process.

[0003] Currently, most linear cooling systems use fixed-frequency compressors. Compressors are selected based on the maximum cooling capacity required during the linear cooling process, which results in higher overall compressor energy consumption. Furthermore, the cooling capacity varies significantly during linear cooling, making the control of the evaporator and condenser fans crucial. Insufficient airflow from these fans affects system reliability and cooling capacity utilization, while excessive airflow leads to poor energy efficiency.

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

[0005] This invention provides a linear cooling control method for an environmental test chamber and an environmental test chamber, in order to solve the problem of poor energy efficiency of existing linear cooling control methods for environmental test chambers.

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

[0007] The internal temperature, suction pressure of the variable frequency compressor, and discharge pressure of the variable frequency compressor of the controlled environment test chamber are obtained.

[0008] The linear cooling rate of the controlled environment test chamber is calculated based on preset temperature parameters;

[0009] A database is obtained based on the chamber temperature, the variable frequency compressor suction pressure, the variable frequency compressor discharge pressure, and the linear cooling rate. 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 environment test chamber are calculated respectively.

[0010] Based on the calculated target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan, the variable frequency compressor, the electronic expansion valve, the evaporator fan, and the condenser fan of the test chamber under control are respectively controlled to achieve linear cooling control of the test chamber under control.

[0011] Optionally, the step of obtaining a database based on the chamber temperature, the variable frequency compressor suction pressure, the variable frequency compressor discharge pressure, and the linear cooling rate, and calculating the target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan for the controlled environment test chamber based on the database includes:

[0012] Based on the temperature inside the chamber and the linear cooling rate, a first database is obtained;

[0013] The initial speed of the variable frequency compressor is determined based on the first database;

[0014] A second database is obtained based on the intake pressure and discharge pressure of the variable frequency compressor.

[0015] The corrected speed of the variable frequency compressor is determined based on the second database;

[0016] The target speed of the variable frequency compressor in the controlled environment test chamber is calculated based on the initial speed and the corrected speed of the variable frequency compressor.

[0017] Optionally, the step of obtaining a database based on the chamber temperature, the variable frequency compressor suction pressure, the variable frequency compressor discharge pressure, and the linear cooling rate, and calculating the target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan for the controlled environment test chamber based on the database, further includes:

[0018] A third database is obtained based on the target speed of the variable frequency compressor and the linear cooling rate;

[0019] The initial opening degree of the electronic expansion valve is determined based on the third database;

[0020] A fourth database is obtained based on the temperature inside the chamber and the compression ratio of the variable frequency compressor calculated from the suction pressure and discharge pressure of the variable frequency compressor.

[0021] The corrected opening degree of the electronic expansion valve is determined based on the fourth database;

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

[0023] Optionally, the step of obtaining a database based on the chamber temperature, the variable frequency compressor suction pressure, the variable frequency compressor discharge pressure, and the linear cooling rate, and calculating the target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan for the controlled environment test chamber based on the database, further includes:

[0024] The fifth database is obtained based on the target opening degree of the electronic expansion valve and the target speed of the variable frequency compressor;

[0025] The initial speed of the evaporator fan is determined based on the fifth database;

[0026] The sixth database is obtained based on the temperature inside the chamber and the suction pressure of the variable frequency compressor;

[0027] The corrected speed of the evaporator fan is determined based on the sixth database.

[0028] The target speed of the evaporator fan is calculated based on the initial speed of the evaporator fan and the corrected speed of the evaporator fan.

[0029] Optionally, the step of obtaining a database based on the chamber temperature, the variable frequency compressor suction pressure, the variable frequency compressor discharge pressure, and the linear cooling rate, and calculating the target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan for the controlled environment test chamber based on the database, further includes:

[0030] The seventh database is obtained based on the target speed of the variable frequency compressor and the discharge pressure of the variable frequency compressor;

[0031] The target speed of the condenser fan is determined based on the seventh database.

[0032] Optionally, calculating the target speed of the variable frequency compressor in the controlled environment test chamber based on the initial speed 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 in the controlled environment test chamber.

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

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

[0036] Optionally, calculating the target speed of the evaporator fan based on 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, wherein the control system executes the linear cooling control method of the environmental test chamber according to any one of claims 1-8;

[0039] The control system includes a display unit, a sensor unit, and a control unit. The sensor unit is disposed inside the housing, the display unit is disposed on the surface of the housing, and the control unit is disposed inside or outside the housing. The display unit and the sensor unit are electrically connected to the control unit.

[0040] The refrigeration system is installed inside the housing 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 circuit.

[0041] Optionally, the sensor unit includes an internal temperature sensor, a variable frequency compressor suction pressure sensor, and a variable frequency compressor discharge pressure sensor; the variable frequency compressor suction pressure sensor and the variable frequency compressor discharge pressure sensor are respectively located 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 data acquisition and calculation control module.

[0043] The data acquisition and calculation control module is electrically connected to the internal temperature sensor; 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; and the evaporator fan speed control module is electrically connected to the evaporator fan.

[0044] The technical solution provided by this invention, by accurately calculating the target speed of the variable frequency compressor, matches the compressor's cooling capacity with the required cooling capacity, effectively reducing system energy consumption and improving energy efficiency; by accurately calculating the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan, it effectively improves the system's operational reliability while reducing fan energy consumption, thus solving the problem of poor energy efficiency in existing linear cooling control methods for environmental test chambers.

[0045] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 A flowchart illustrating a linear cooling control method for an environmental test chamber provided in an embodiment of the present invention;

[0048] Figure 2 This is a structural schematic diagram of an environmental test chamber provided in an embodiment of the present invention. Detailed Implementation

[0049] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort 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, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0051] Figure 1 A flowchart of a linear cooling control method for an environmental test chamber provided in an embodiment of the present invention is shown below. Figure 1 The linear cooling control method includes:

[0052] S110: Obtain the internal temperature of the controlled environment test chamber, the suction pressure of the variable frequency compressor, and the discharge pressure of the variable frequency compressor.

[0053] An environmental test chamber is a device used to simulate various environmental conditions to test the performance and reliability of products or materials under different environments. Environmental test chambers can simulate various environmental factors, such as temperature, humidity, air pressure, light, and vibration. By placing products or materials inside the test chamber and testing them under set environmental conditions for a period of time, it is possible to understand the conditions the product might face in actual use environments, allowing for product improvement and optimization.

[0054] Specifically, the controlled environment test chamber is equipped with an internal temperature sensor, a variable frequency compressor suction pressure sensor, and a variable frequency compressor discharge pressure sensor. The internal temperature, suction pressure, and discharge pressure of the variable frequency compressor can be obtained from the internal temperature sensor, the suction pressure of the variable frequency compressor, and the discharge pressure of the variable frequency compressor, respectively.

[0055] S120. Calculate the linear cooling rate of the controlled environment test chamber based on preset temperature parameters.

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

[0057] Specifically, the difference between the initial temperature and the final temperature is calculated, and the ratio of this difference to the total cooling time is determined as the linear cooling rate of the controlled environment test chamber.

[0058] S130. Based on the chamber temperature, variable frequency compressor suction pressure, variable frequency compressor discharge pressure, and linear cooling rate, a database is obtained, and based on the database, the target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan of the test chamber under control are calculated respectively.

[0059] Specifically, a database is obtained based on the chamber temperature, variable frequency compressor suction pressure, variable frequency compressor discharge pressure, and linear cooling rate. Based on the database, the initial and corrected speeds of the variable frequency compressor, the initial and corrected openings of the electronic expansion valve, the initial and corrected speeds of the evaporator fan, and the target speed of the condenser fan are determined. Based on the initial and corrected speeds of the variable frequency compressor, the initial and corrected openings of the electronic expansion valve, and the initial and corrected speeds of the evaporator fan, the target speeds of the variable frequency compressor, the electronic expansion valve, and the evaporator fan of the controlled environment test chamber are calculated.

[0060] S140: Based on the calculated target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan, the variable frequency compressor, the electronic expansion valve, the evaporator fan, and the condenser fan of the test chamber under control are respectively controlled to achieve linear cooling control of the test chamber under control.

[0061] Specifically, the variable frequency compressor, electronic expansion valve, evaporator fan, and condenser fan of the test chamber are controlled by using the calculated target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan, so as to achieve linear cooling control of the test chamber. Since the calculation of the target speed of the variable frequency compressor involves the linear cooling rate, which can characterize the cooling capacity, the target speed of the variable frequency compressor is further calculated based on the linear cooling rate. The target opening degree 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 degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan, the operation of the variable frequency compressor, the electronic expansion valve, the evaporator fan, and the condenser fan of the test chamber under test is controlled respectively, thereby achieving stable linear cooling control of the test chamber under test. 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 cooling capacity demand, effectively reducing the energy consumption of the compressor and fan while ensuring the reliability of the system.

[0062] The technical solution provided by this invention, by accurately calculating the target speed of the variable frequency compressor, matches the compressor's cooling capacity with the required cooling capacity, effectively reducing system energy consumption and improving energy efficiency; by accurately calculating the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan, it effectively improves the system's operational reliability while reducing fan energy consumption, thus solving the problem of poor energy efficiency in existing linear cooling control methods for environmental test chambers.

[0063] Optionally, a database is obtained based on the chamber temperature, variable frequency compressor suction pressure, variable frequency compressor discharge pressure, and linear cooling rate. Based on this database, the target speeds of the variable frequency compressor, electronic expansion valve opening, evaporator fan, and condenser fan for the controlled environment test chamber are calculated, including:

[0064] The first database is obtained based on the internal temperature and linear cooling rate; the initial speed of the variable frequency compressor is determined based on the first database.

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

[0066] Table 1

[0067]

[0068]

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

[0070] A second database is obtained based on the suction pressure and discharge pressure of the variable frequency compressor; the corrected speed of the variable frequency compressor is determined based on the second database.

[0071] Specifically, based on the suction pressure and discharge pressure of the variable frequency compressor, a second database is obtained through experimental calibration; the corrected speed of the variable frequency compressor is determined based on the second database. See Table 2 for details.

[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 discharge 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] Calculate the target speed of the variable frequency compressor in the controlled environment test chamber based on the initial speed and the corrected speed of the variable frequency compressor.

[0076] Optionally, the target speed of the variable frequency compressor in the controlled environment test chamber is calculated based on the initial speed and the corrected speed of the variable frequency compressor, including:

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

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

[0079] F = F0 + ΔF; where 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, based on the chamber temperature, variable frequency compressor suction pressure, variable frequency compressor discharge pressure, and linear cooling rate, a database is obtained, and the target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan for the controlled environment test chamber are calculated based on the database. This also includes:

[0081] A third database is obtained based on the target speed and linear cooling rate of the variable frequency compressor; the initial opening of the electronic expansion valve is determined based on the third database.

[0082] Specifically, based on the target speed and linear cooling rate of the variable frequency compressor, a third database is obtained through experimental calibration. The initial opening of the electronic expansion valve is then determined based on 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 represents the linear cooling rate, F represents the target speed of the variable frequency compressor, and E0 represents the initial opening of the electronic expansion valve.

[0086] The fourth database is obtained based on the internal temperature of the chamber and the compression ratio of the variable frequency compressor calculated from the suction pressure and discharge pressure of the variable frequency compressor; the corrected opening degree of the electronic expansion valve is determined based on the fourth database.

[0087] Specifically, based on the internal temperature of the chamber and the compression ratio of the variable frequency compressor calculated by the suction pressure and discharge pressure of the variable frequency compressor, a fourth database is obtained after experimental calibration; the corrected opening degree of the electronic expansion valve is determined based on the fourth database, as shown in Table 4 below.

[0088] Table 4

[0089]

[0090]

[0091] In Table 4, T is the internal temperature of the chamber, 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 discharge pressure of the variable frequency compressor, and ΔE is the corrected opening of the electronic expansion valve.

[0092] Calculate the target opening of the electronic expansion valve based on its initial opening and corrected opening.

[0093] Optionally, the target opening of the electronic expansion valve is calculated based on the initial opening and the corrected opening of the electronic expansion valve, including:

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

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

[0096] E = E0 + ΔE; where 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, based on the chamber temperature, variable frequency compressor suction pressure, variable frequency compressor discharge pressure, and linear cooling rate, a database is obtained, and the target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan for the controlled environment test chamber are calculated based on the database. This also includes:

[0098] The fifth database is obtained based on the target opening degree of the electronic expansion valve and the target speed of the variable frequency compressor; the initial speed of the evaporator fan is determined based on the fifth database.

[0099] Specifically, based on the target opening degree of the electronic expansion valve and the target speed of the variable frequency compressor, the fifth database is obtained through experimental calibration; the initial speed of the evaporator fan is determined based on 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 represents the target opening degree of the electronic expansion valve, F represents the target speed of the variable frequency compressor, and A0 represents the initial speed of the evaporator fan.

[0103] The sixth database is obtained based on the internal temperature and the suction pressure of the variable frequency compressor; the corrected speed of the evaporator fan is determined based on the sixth database.

[0104] Specifically, based on the internal temperature and the suction pressure of the variable frequency compressor, a sixth database was obtained through testing and calibration; the corrected speed of the evaporator fan was determined based on 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 represents the internal temperature of the chamber, LP represents the suction pressure of the variable frequency compressor, and ΔA represents the corrected speed of the evaporator fan.

[0108] Calculate the target speed of the evaporator fan based on the initial speed and the corrected speed of the evaporator fan.

[0109] Optionally, the target speed of the evaporator fan can be calculated based on the initial speed and the corrected speed of the evaporator fan, including:

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

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

[0112] A = A0 + ΔA; where 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, based on the chamber temperature, variable frequency compressor suction pressure, variable frequency compressor discharge pressure, and linear cooling rate, a database is obtained, and the target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan for the controlled environment test chamber are calculated based on the database. This also includes:

[0114] The seventh database is obtained based on the target speed and discharge pressure of the variable frequency compressor; the target speed of the condenser fan is determined based on the seventh database.

[0115] Specifically, based on the target speed and discharge pressure of the variable frequency compressor, the seventh database is obtained through experimental calibration; the target speed of the condenser fan is determined based on 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 represents the target speed of the condenser fan, F represents the target speed of the variable frequency compressor, and HP represents the discharge pressure of the variable frequency compressor.

[0119] The technical solution provided by this invention determines a database based on the chamber temperature, variable frequency compressor suction pressure, variable frequency compressor discharge pressure, and linear cooling rate. Based on the database, it 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, so that the compressor cooling capacity matches the required cooling capacity, effectively reducing system energy consumption, improving system operational reliability, and solving the problem of poor energy efficiency in existing linear cooling control methods for environmental test chambers.

[0120] Figure 2 This is a structural schematic diagram of an environmental test chamber provided in an embodiment of the present invention. See also: Figure 2 The environmental test chamber includes a chamber body, a control system, and a refrigeration system. The control system executes the linear cooling control method for the environmental test chamber 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 located inside the enclosure, the display unit is located on the surface of the enclosure, and the control unit is located inside or outside the enclosure. The display unit and the sensor unit are electrically connected to the control unit.

[0122] The refrigeration system is installed inside the cabinet and includes 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 circuit.

[0123] Optionally, the sensor unit includes an internal temperature sensor 1, a variable frequency compressor suction pressure sensor 8, and a variable frequency compressor discharge pressure sensor 9; the variable frequency compressor suction pressure sensor 8 and the variable frequency compressor discharge pressure sensor 9 are respectively located 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 data acquisition and calculation control module 14.

[0125] The data acquisition and calculation control module 14 is electrically connected to the internal temperature sensor 1; 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 data acquisition and calculation control module 14 is used to acquire the internal temperature, variable frequency compressor suction pressure, and variable frequency compressor discharge pressure of the controlled environment test chamber, and calculate the linear cooling rate of the controlled environment test chamber based on preset temperature parameters. Based on the internal temperature, variable frequency compressor suction pressure, variable frequency compressor discharge pressure, and linear cooling rate, a database is obtained, and based on the database, the target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan are calculated respectively. Then, based on the calculated target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan, the... The target speed of the condenser fan generates a corresponding control command, which is then transmitted 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. This enables 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 to control the electronic expansion valve 5, the evaporator fan 7, the condenser fan 4, and the variable frequency compressor 2 of the environmental test chamber to perform corresponding actions based on the control commands, thereby achieving linear cooling control of the environmental test chamber.

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

[0128] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0129] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A linear cooling control method for an environmental test chamber, characterized in that, include: The internal temperature, suction pressure of the variable frequency compressor, and discharge pressure of the variable frequency compressor of the controlled environment test chamber are obtained. The linear cooling rate of the controlled environment test chamber is calculated based on preset temperature parameters; A database is obtained based on the chamber temperature, the variable frequency compressor suction pressure, the variable frequency compressor discharge pressure, and the linear cooling rate. 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 environment test chamber 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 variable frequency compressor, the electronic expansion valve, the evaporator fan, and the condenser fan of the test chamber under control are respectively controlled to achieve linear cooling control of the test chamber under control. The process of obtaining a database based on the chamber temperature, the variable frequency compressor suction pressure, the variable frequency compressor discharge pressure, and the linear cooling rate, and then calculating the target speed of the variable frequency compressor, the target opening degree of the electronic expansion valve, the target speed of the evaporator fan, and the target speed of the condenser fan for the controlled environment test chamber based on the database, includes: Based on the temperature inside the chamber and the linear cooling rate, a first database is obtained; The initial speed of the variable frequency compressor is determined based on the first database; A second database is obtained based on the intake pressure and discharge pressure of the variable frequency compressor. The corrected speed of the variable frequency compressor is determined based on the second database; Calculate the target speed of the variable frequency compressor in the controlled environment test chamber based on the initial speed and the corrected speed of the variable frequency compressor. A third database is obtained based on the target speed of the variable frequency compressor and the linear cooling rate; The initial opening degree of the electronic expansion valve is determined based on the third database; A fourth database is obtained based on the temperature inside the chamber and the compression ratio of the variable frequency compressor calculated from the suction pressure and discharge pressure of the variable frequency compressor. The corrected opening degree of the electronic expansion valve is determined based on the fourth database; The target opening of the electronic expansion valve is calculated based on the initial opening and the corrected opening of the electronic expansion valve. The fifth database is obtained based on the target opening degree of the electronic expansion valve and the target speed of the variable frequency compressor; The initial speed of the evaporator fan is determined based on the fifth database; The sixth database is obtained based on the temperature inside the chamber and the suction pressure of the variable frequency compressor; The corrected speed of the evaporator fan is determined based on the sixth database. The target speed of the evaporator fan is calculated based on the initial speed of the evaporator fan and the corrected speed of the evaporator fan. The seventh database is obtained based on the target speed of the variable frequency compressor and the discharge pressure of the variable frequency compressor; The target speed of the condenser fan is determined based on the seventh database.

2. The linear cooling control method according to claim 1, characterized in that, The step of calculating the target speed of the variable frequency compressor in the controlled environment test chamber based on the initial speed and the corrected speed of the variable frequency compressor includes: 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 in the controlled environment test chamber.

3. The linear cooling control method according to claim 1, characterized in that, The step of calculating the target opening of the electronic expansion valve based on the initial opening and the corrected opening of the electronic expansion valve includes: The sum of the initial opening degree and the corrected opening degree of the electronic expansion valve is determined as the target opening degree of the electronic expansion valve.

4. The linear cooling control method according to claim 1, characterized in that, The step of calculating the target speed of the evaporator fan based on the initial speed of the evaporator fan and the corrected speed of the evaporator fan includes: 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.

5. An environmental test chamber, characterized in that, The environmental test chamber includes a chamber body, a control system, and a refrigeration system. The control system executes the linear cooling control method for the environmental test chamber according to any one of claims 1-4. The control system includes a display unit, a sensor unit, and a control unit. The sensor unit is disposed inside the housing, the display unit is disposed on the surface of the housing, and the control unit is disposed inside or outside the housing. The display unit and the sensor unit are electrically connected to the control unit. The refrigeration system is installed inside the housing 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 circuit.

6. The environmental test chamber according to claim 5, characterized in that, The sensor unit includes an internal temperature sensor, a variable frequency compressor suction pressure sensor, and a variable frequency compressor discharge pressure sensor; the variable frequency compressor suction pressure sensor and the variable frequency compressor discharge pressure sensor are respectively located 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 data acquisition and calculation control module. The data acquisition and calculation control module is electrically connected to the internal temperature sensor; 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; and the evaporator fan speed control module is electrically connected to the evaporator fan.

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