A method for controlling the cooling of a test chamber and a test chamber

Abstract

The embodiment of the present application discloses a kind of test chamber cooling control method and test chamber, cooling control method includes: the set parameter of test chamber is divided into set quantity of segment by average;The reference increment of each set parameter in each segment is calculated;The target control value of each set parameter in different segment is determined based on each reference increment and the control gain coefficient of each set parameter;Based on the target control value of each set parameter in different segment, each set parameter in corresponding segment is regulated and controlled, to control test chamber to carry out cooling.This application solves the technical problem that the existing environment test chamber only relies on the maximum refrigeration capacity to select the fixed frequency compressor, the fixed frequency compressor has higher energy consumption, and the capacity is wasted in the initial stage of operation, realizes the technical effect of regulating and controlling each set parameter including variable frequency compressor speed in different time periods and high precision, improves the reliability of test chamber operation, and reduces the operation energy consumption of test chamber.

Description

Technical Field

[0001] This invention relates to the field of temperature control technology, and in particular to a cooling control method for a test chamber and a 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 of products or components during the process of cooling from high temperature to low temperature over a certain period of time, as well as the changes in material stress and material properties.

[0003] During linear cooling, the cooling capacity demand increases as the temperature decreases, while 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 start to the end of linear cooling.

[0004] Currently, linear cooling mostly uses fixed-frequency compressors, and the compressor is usually selected based on the maximum cooling capacity required during the linear cooling process. However, this results in higher overall compressor energy consumption during the linear cooling process, leading to higher system operating energy consumption. Summary of the Invention

[0005] This invention provides a cooling control method and test chamber for an environmental test chamber, which solves the technical problems of high energy consumption and wasted capacity in the early stage of operation of the fixed-frequency compressor in the prior art, which relies solely on the maximum cooling capacity for selecting the fixed-frequency compressor.

[0006] This invention provides a cooling control method for a test chamber, the cooling control method comprising:

[0007] The test chamber's set parameters are divided into a set number of segments, wherein the set parameters include at least the variable frequency compressor speed, electronic expansion valve opening, evaporator fan speed, and condenser fan speed.

[0008] Calculate the baseline increment of each set parameter within each segment;

[0009] The target control value of each set parameter in different segments is determined based on each of the benchmark increments and the control gain coefficients of each set parameter. The control gain coefficients of each set parameter are obtained by querying a preset database, which stores the control gain coefficients corresponding to each set parameter determined based on the influence factors of each set parameter in the test chamber.

[0010] Based on the target control values ​​of each set parameter in different segments, the set parameters in the corresponding segments are adjusted to control the cooling of the test chamber.

[0011] Furthermore, the method for establishing the preset database includes:

[0012] The linear cooling rate of the test chamber is determined based on preset temperature parameters, wherein the preset temperature parameters include at least the set starting temperature, the set target temperature, and the target cooling time of the test chamber;

[0013] The cooling section is divided into a set number of segments, and the starting temperature of each segment is calculated.

[0014] Obtain the equipment operating parameters of the test chamber, wherein the equipment operating parameters include at least the variable frequency compressor suction pressure, variable frequency compressor discharge pressure, condensing temperature, condenser liquid supply temperature, evaporation temperature, and evaporator outlet temperature;

[0015] The state parameters of the test chamber are calculated based on the equipment operating parameters, wherein the state parameters include at least the compression ratio of the variable frequency compressor, the subcooling degree of the condenser, and the superheating degree of the evaporator;

[0016] The preset database is established by using the linear cooling rate, the segmented starting temperature, the equipment operating parameters, and the state parameters as influencing factors of the set parameters.

[0017] Furthermore, establishing the preset database by using the linear cooling rate, the segmented starting temperature, the equipment operating parameters, and the state parameters as influencing factors of the set parameters includes:

[0018] A first preset database is established between the first gain coefficient and the linear cooling rate and the segmented starting temperature, and a second preset database is established between the second gain coefficient and the compression ratio of the variable frequency compressor and the subcooling degree of the condenser, wherein the first gain coefficient and the second gain coefficient are both control gain coefficients of the variable frequency compressor speed;

[0019] A third preset database is established between the third gain coefficient and the linear cooling rate and the segmented starting temperature; a fourth preset database is established between the fourth gain coefficient and the variable frequency compressor speed and the condenser subcooling degree; and a fifth preset database is established between the fifth gain coefficient and the variable frequency compressor suction pressure and the evaporator superheat degree. The third gain coefficient, the fourth gain coefficient and the fifth gain coefficient are all control gain coefficients of the electronic expansion valve opening degree.

[0020] A sixth preset database is established between the sixth gain coefficient and the opening degree of the electronic expansion valve and the segmented starting temperature. A seventh preset database is established between the seventh gain coefficient and the suction pressure of the variable frequency compressor and the superheat of the evaporator. The sixth gain coefficient and the seventh gain coefficient are both control gain coefficients of the evaporator fan speed.

[0021] An eighth preset database is established between the eighth gain coefficient and the discharge pressure of the variable frequency compressor and the subcooling degree of the condenser, and a ninth preset database is established between the ninth gain coefficient and the speed of the variable frequency compressor and the segmented starting temperature. The eighth gain coefficient and the ninth gain coefficient are both control gain coefficients of the condenser fan speed.

[0022] Furthermore, calculating the baseline increment of each set parameter within each segment includes:

[0023] Based on formula Calculate the reference increment of the compressor speed, where Δf is the reference increment of the compressor speed, and F max F is the maximum speed of the variable frequency compressor. min M represents the minimum speed of the variable frequency compressor, and M represents the number of speed segments of the variable frequency compressor.

[0024] Based on formula Calculate the reference increment of the compressor speed, where Δe is the reference increment of the electronic expansion valve opening, and E max E represents the maximum opening of the electronic expansion valve. min A represents the minimum opening degree of the electronic expansion valve, and A represents the number of segments in the opening degree of the electronic expansion valve.

[0025] Based on formula Calculate the base increment of the evaporator fan speed, where Δh is the base increment of the evaporator fan speed, and H... max H is the maximum speed of the evaporator fan. min B represents the minimum speed of the evaporator fan, and B represents the number of speed segments of the evaporator fan.

[0026] Based on formula Calculate the base increment of the condenser fan speed, where Δd is the base increment of the condenser fan speed, and D... max D is the maximum speed of the condenser fan. min C represents the minimum speed of the condenser fan, and C represents the number of speed segments of the condenser fan.

[0027] Furthermore, determining the target control value of each set parameter in different segments based on each of the aforementioned reference increments and the control gain coefficient of each of the aforementioned set parameters includes:

[0028] Based on the formula F=F min +Δf(w1+w2) determines the speed of the variable frequency compressor in different segments, where 0≤w1+w2≤M, F is the speed of the variable frequency compressor, Δf is the reference increment of the compressor speed, w1 is the first gain coefficient, w2 is the second gain coefficient, and M is the number of segments of the variable frequency compressor speed.

[0029] Based on the formula E = E min +Δe(k1+k2+k3) determines the opening degree of the electronic expansion valve in different segments, where 0≤k1+k2+k3≤A, E is the opening degree of the electronic expansion valve, Δe is the reference increment of the opening degree of the electronic expansion valve, k1 is the third gain coefficient, k2 is the fourth gain coefficient, k3 is the fifth gain coefficient, and A is the number of segments of the opening degree of the electronic expansion valve.

[0030] Based on the formula H = H min +Δh(r1+r2) determines the evaporator fan speed in different segments, where 0≤r1+r2≤B, H is the evaporator fan speed, Δh is the base increment of the evaporator fan speed, r1 is the sixth gain coefficient, r2 is the seventh gain coefficient, and B is the number of segments of the evaporator fan speed.

[0031] Based on the formula D = D min +Δd(p1+p2) determines the condenser fan speed in different segments, where 0≤p1+p2≤C, D is the condenser fan speed, Δd is the base increment of the condenser fan speed, p1 is the eighth gain coefficient, p2 is the ninth gain coefficient, and C is the number of segments of the condenser fan speed.

[0032] Furthermore, the cooling section is divided into a set number of segments, and the starting temperature of each segment is calculated, including:

[0033] Divide the cooling section into n equal segments and use the formula Calculate the initial temperature of each segment;

[0034] Where i = 1, 2, ..., n, n is the number of segments in the cooling section, i represents the i-th segment among the n segments, T0 is the starting temperature of the segment, V is the linear cooling rate, and t is the target cooling time.

[0035] Furthermore, calculating the state parameters of the test chamber based on the state parameters includes:

[0036] The compression ratio of the variable frequency compressor is obtained by comparing the discharge pressure of the variable frequency compressor with the intake pressure of the variable frequency compressor.

[0037] The condenser subcooling is obtained by subtracting the condensation temperature from the condenser supply temperature.

[0038] The evaporator superheat is obtained by subtracting the evaporator outlet temperature from the evaporation temperature.

[0039] This invention also provides a test chamber, which includes a chamber body, a control system, and a refrigeration system. The control system executes the cooling control method of the test chamber described in any of the above embodiments.

[0040] 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.

[0041] The refrigeration system is installed inside the enclosure and includes a variable frequency compressor, a condenser, a condenser fan, an evaporator, an evaporator fan, and an electronic expansion valve;

[0042] The evaporator, the electronic expansion valve, the condenser, and the variable frequency compressor are connected in series to form a circuit. The condenser fan is located at the condenser, and the evaporator fan is located at the evaporator.

[0043] Furthermore, the sensor unit includes an internal temperature sensor, an evaporator outlet temperature sensor, a variable frequency compressor suction pressure sensor, a variable frequency compressor discharge pressure sensor, and a condenser liquid supply temperature sensor.

[0044] The temperature sensor inside the box is installed inside the box.

[0045] The evaporator outlet temperature sensor is located at the outlet of the evaporator.

[0046] The variable frequency compressor suction pressure sensor is located at the intake port of the variable frequency compressor, and the variable frequency compressor discharge pressure sensor is located at the discharge port of the variable frequency compressor.

[0047] The condenser liquid supply temperature sensor is located at the liquid supply port of the condenser.

[0048] Furthermore, 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;

[0049] The data acquisition, calculation, and control module is electrically connected to the sensors in the sensor unit, the evaporator fan speed control module, the variable frequency compressor speed control module, the electronic expansion valve opening control module, and the condenser fan speed control module, respectively.

[0050] The evaporator fan speed control module is electrically connected to the evaporator fan.

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

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

[0053] The condenser fan speed control module is electrically connected to the condenser fan.

[0054] This invention discloses a cooling control method and a test chamber for a test chamber. The cooling control method includes: dividing the set parameters of the test chamber into a set number of segments; calculating the reference increment of each set parameter in each segment; determining the target control value of each set parameter in different segments based on each reference increment and the control gain coefficient of each set parameter; and adjusting each set parameter in the corresponding segment based on the target control value of each set parameter in different segments to control the cooling of the test chamber. This invention solves the technical problems of high energy consumption and wasted capacity in the initial operation of fixed-frequency compressors in existing environmental test chambers, which rely solely on maximum cooling capacity for compressor selection. It achieves the technical effect of time-segmented, high-precision control of set parameters, including the speed of variable-frequency compressors, improving the reliability of the test chamber operation and reducing its energy consumption. Attached Figure Description

[0055] Figure 1 This is a structural diagram of a cooling control method for a test chamber provided in an embodiment of the present invention;

[0056] Figure 2 This is a structural diagram of a test chamber provided in an embodiment of the present invention. Detailed Implementation

[0057] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0058] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this invention are used to distinguish different objects, not to limit a specific order. The various embodiments of this invention described below can be performed individually or in combination with each other; the embodiments of this invention do not impose specific limitations in this regard.

[0059] Figure 1 This is a structural diagram of a cooling control method for a test chamber provided in an embodiment of the present invention.

[0060] like Figure 1 As shown, the cooling control method of this test chamber specifically includes the following steps:

[0061] S101, the set parameters of the test chamber are divided into a set number of segments, wherein the set parameters include at least the variable frequency compressor speed, the electronic expansion valve opening, the evaporator fan speed and the condenser fan speed.

[0062] Specifically, the traditional fixed-frequency compressor is replaced with a variable-frequency compressor. Through the compressor's variable-frequency technology, the output of cooling capacity is dynamically matched to achieve on-demand cooling, avoiding the high energy consumption problem caused by the continuous full-load operation of the traditional compressor. Since the cooling capacity changes significantly during the linear cooling process, the opening of the electronic expansion valve can change the refrigerant flow into the evaporator to ensure that the cooling capacity output matches the system demand. For the evaporator and condenser, the control of the evaporator fan and condenser fan is also crucial. If the air volume of the evaporator fan and condenser fan is too small, it will affect the reliability of the system operation and the cooling capacity utilization. If the air volume is too large, the energy efficiency will be poor. Therefore, it is also necessary to regulate the evaporator fan and condenser fan to assist in controlling the cooling environment of the test chamber.

[0063] After setting the parameters as the variable frequency compressor speed, electronic expansion valve opening, evaporator fan speed, and condenser fan speed, each parameter is divided into average segments. Subsequent adjustments to each segment improve control accuracy. It should be noted that the number of segments for each parameter can be the same or different; no specific restrictions are imposed here.

[0064] S102, calculate the baseline increment of each set parameter in each segment.

[0065] Specifically, each set parameter has a maximum and minimum limit. When the equipment is operating, its set parameter cannot exceed the maximum value MAX and minimum value MIN that the equipment can achieve. Therefore, within each segment of the set parameter, the difference between the maximum value MAX and the minimum value MIN (MAX-MIN) is then divided equally into each segment, which is the base increment of the set parameter within a segment. For example, if the segment is X, then the base increment is (MAX-MIN) / X.

[0066] Optionally, S102 specifically includes:

[0067] Based on formula Calculate the baseline increment of the compressor speed, where Δf is the baseline increment of the compressor speed, and F... max F is the maximum speed of the variable frequency compressor. min M represents the minimum speed of the variable frequency compressor, and M represents the number of speed segments of the variable frequency compressor.

[0068] Based on formula Calculate the baseline increment of compressor speed, where Δe is the baseline increment of electronic expansion valve opening, and E max E represents the maximum opening of the electronic expansion valve. min A represents the minimum opening degree of the electronic expansion valve, and A represents the number of segments in the opening degree of the electronic expansion valve.

[0069] Based on formula Calculate the baseline increment of the evaporator fan speed, where Δh is the baseline increment of the evaporator fan speed, and H... max H is the maximum speed of the evaporator fan. min B represents the minimum speed of the evaporator fan, and B represents the number of speed segments of the evaporator fan.

[0070] Based on formula Calculate the baseline increment of the condenser fan speed, where Δd is the baseline increment of the condenser fan speed, and D... max D is the maximum speed of the condenser fan. min C represents the minimum speed of the condenser fan, and C represents the number of speed segments of the condenser fan.

[0071] S103, based on each benchmark increment and the control gain coefficient of each set parameter, determine the target control value of each set parameter in different segments. The control gain coefficient of each set parameter is obtained by querying a preset database, which stores the control gain coefficient corresponding to each set parameter determined based on the influence factors of each set parameter in the test chamber.

[0072] Specifically, during the cooling operation of the test chamber, different set parameters have different influencing factors. If one influencing factor changes, the corresponding set parameter will also change. Therefore, by conducting experiments beforehand, the control gain coefficient of the corresponding set parameter can be determined using the influencing factors, and a corresponding database can be established. After obtaining the current operating parameters of each device in the test chamber (i.e., the device operating parameters below), the corresponding database is queried based on the obtained current operating parameters to obtain the control gain coefficient of each device parameter. Finally, the target control value of the device parameter within the segment corresponding to the current operating parameters is determined using the baseline increment and the queried control gain coefficient.

[0073] Optionally, S103 specifically includes:

[0074] Based on the formula F=F min +Δf(w1+w2) determines the variable frequency compressor speed in different segments, where 0≤w1+w2≤M, F is the variable frequency compressor speed, Δf is the base increment of the compressor speed, w1 is the first gain coefficient, w2 is the second gain coefficient, and M is the number of segments of the variable frequency compressor speed.

[0075] Based on the formula E = E min +Δe(k1+k2+k3) determines the opening degree of the electronic expansion valve in different segments, where 0≤k1+k2+k3≤A, E is the opening degree of the electronic expansion valve, Δe is the reference increment of the opening degree of the electronic expansion valve, k1 is the third gain coefficient, k2 is the fourth gain coefficient, k3 is the fifth gain coefficient, and A is the number of segments of the opening degree of the electronic expansion valve.

[0076] Based on the formula H = H min +Δh(r1+r2) determines the evaporator fan speed in different segments, where 0≤r1+r2≤B, H is the evaporator fan speed, Δh is the base increment of the evaporator fan speed, r1 is the sixth gain coefficient, r2 is the seventh gain coefficient, and B is the number of segments of the evaporator fan speed.

[0077] Based on the formula D = D min +Δd(p1+p2) determines the condenser fan speed in different segments, where 0≤p1+p2≤C, D is the condenser fan speed, Δd is the base increment of the condenser fan speed, p1 is the eighth gain coefficient, p2 is the ninth gain coefficient, and C is the number of segments of the condenser fan speed.

[0078] Specifically, M, A, B, and C are all determined by the control precision of the corresponding set parameters and can be set as needed. It should be noted that for the first gain coefficient w1 and the second gain coefficient w2, since the gain coefficient w multiplied by the number of equally divided segments M is the maximum value of the increment, i.e., the maximum value of Δf, it is necessary to limit the maximum value of Δf to not exceed the maximum speed F. max It is necessary to specify that 0 ≤ w1 + w2 ≤ M. Similarly, the constraints for other gain coefficients are similar to those for the gain coefficient w.

[0079] S104 adjusts the set parameters in the corresponding segments based on the target control values ​​of each set parameter in different segments in order to control the cooling of the test chamber.

[0080] Specifically, by adjusting the set parameters based on the target control values ​​obtained in different segments, the control accuracy is improved, and the test chamber can stably and reliably achieve the linear cooling process.

[0081] This invention solves the technical problems of high energy consumption and wasted capacity in the early stages of operation of environmental test chambers, which rely solely on the maximum cooling capacity for selecting a fixed-frequency compressor. It achieves the technical effect of time-segmented and high-precision regulation of various set parameters, including the speed of the variable-frequency compressor, thus improving the reliability of the test chamber operation and reducing its energy consumption. This is achieved by dividing the test chamber's set parameters into average segments and determining the control gain coefficients for each set parameter based on their influence factors within the test chamber. Then, the target control value for each set parameter within each segment is determined using the control gain coefficients in different segments.

[0082] Optionally, the default methods for creating the database include:

[0083] S1, determine the linear cooling rate of the test chamber based on preset temperature parameters, wherein the preset temperature parameters include at least the set starting temperature, the set target temperature and the target cooling time of the test chamber.

[0084] Specifically, the preset temperature parameters of the test chamber include the set initial temperature T0 and the set target temperature T0. SV And the target cooling time t. Based on the preset temperature parameters, use the formula... Determine the linear cooling rate V of the controlled environment test chamber.

[0085] S2, divide the cooling section into a set number of segments and calculate the starting temperature of each segment.

[0086] Optionally, step S2 specifically includes:

[0087] Divide the cooling section into n equal segments and use the formula Calculate the starting temperature of each segment; where i = 1, 2, ..., n, n is the number of cooling segments, i represents the i-th segment among n segments, T0 is the starting temperature of the segment, V is the linear cooling rate, and t is the target cooling time.

[0088] S3, obtain the equipment operating parameters of the test chamber, including at least the variable frequency compressor suction pressure, variable frequency compressor discharge pressure, condensing temperature, condenser liquid supply temperature, evaporation temperature, and evaporator outlet temperature.

[0089] Specifically, the environmental test chamber is equipped with a control system, which includes a display unit, a sensor unit, and a control unit. The sensor unit includes a chamber temperature sensor, an evaporator outlet temperature sensor, a variable frequency compressor suction pressure sensor, a variable frequency compressor discharge pressure sensor, and a condenser liquid supply temperature sensor, which can acquire the current temperature inside the test chamber and the temperature parameters of each device in real time.

[0090] Among them, the variable frequency compressor discharge pressure sensor is used to obtain the discharge pressure of the variable frequency compressor, and then the condensing temperature of the test chamber is calculated based on the discharge pressure; the variable frequency compressor suction pressure sensor is used to obtain the suction pressure of the variable frequency compressor, and then the evaporation temperature of the test chamber is calculated based on the suction pressure; the temperature parameters of other equipment are directly obtained by the corresponding sensors.

[0091] S4. Calculate the state parameters of the test chamber based on the equipment operating parameters. The state parameters include at least the compression ratio of the variable frequency compressor, the subcooling of the condenser, and the superheat of the evaporator.

[0092] Optionally, step S4 specifically includes:

[0093] The compression ratio of the variable frequency compressor is obtained by comparing its discharge pressure with its suction pressure; the condenser subcooling is obtained by subtracting its condensing temperature from its liquid supply temperature; and the evaporator superheat is obtained by subtracting its outlet temperature from its evaporation temperature.

[0094] Specifically, after obtaining the discharge pressure HP and suction pressure LP of the variable frequency compressor, HP is compared with LP to obtain the compression ratio PR of the variable frequency compressor = HP / LP; after obtaining the condensing temperature T... con With condenser supply liquid temperature T 11 After that, T con With T 11 Subtracting the two, we get the condenser subcooling SC = T. con -T 11 ; after obtaining the evaporator outlet temperature T8 and the evaporation temperature T eva Next, T8 and T eva Subtracting the two, we get the evaporator superheat SH = T8 - Teva .

[0095] S5 establishes a preset database by using linear cooling rate, segmented starting temperature, equipment operating parameters, and state parameters as influencing factors of the set parameters.

[0096] Optionally, step S5 specifically includes:

[0097] S51, establish a first preset database between the first gain coefficient and the linear cooling rate and the segmented starting temperature, and establish a second preset database between the second gain coefficient and the compression ratio of the variable frequency compressor and the subcooling degree of the condenser, wherein the first gain coefficient and the second gain coefficient are both control gain coefficients of the variable frequency compressor speed.

[0098] For example, see Tables 1 and 2, Table 1 shows the relationship between the first gain coefficient w1 and the linear cooling rate V, and the segmented starting temperature (T0). i The first preset database between the second gain coefficient w2 and the compression ratio PR of the variable frequency compressor and the subcooling degree SC of the condenser, where i represents the i-th segment and j represents the number of the linear cooling rate V or the compression ratio PR of the variable frequency compressor.

[0099] Table 1. First Preset Database

[0100]

[0101]

[0102] Table 2. Second Preset Database

[0103] <![CDATA[SC1]]> <![CDATA[SC2]]> … <![CDATA[SC i ]]> <![CDATA[PR1]]> <![CDATA[w 2_11 ]]> <![CDATA[w 2_12 ]]> … <![CDATA[w 2_1j ]]> <![CDATA[PR2]]> <![CDATA[w 2_21 ]]> <![CDATA[w 2_22 ]]> … <![CDATA[w 2_2j ]]> … … … … … <![CDATA[PR j ]]> <![CDATA[w 2_i1 ]]> <![CDATA[w 2_i2 ]]> … <![CDATA[w 2_ij ]]>

[0104] S52, establish a third preset database between the third gain coefficient and the linear cooling rate and the segmented starting temperature, establish a fourth preset database between the fourth gain coefficient and the variable frequency compressor speed and the condenser subcooling, and establish a fifth preset database between the fifth gain coefficient and the variable frequency compressor suction pressure and the evaporator superheat. Among them, the third gain coefficient, the fourth gain coefficient and the fifth gain coefficient are all control gain coefficients of the electronic expansion valve opening.

[0105] For example, see Tables 3, 4 and 5. Table 3 shows the relationship between the third gain coefficient k1 and the linear cooling rate V, and the segmented starting temperature (T0). iThe third preset database is between the fourth gain coefficient k2 and the variable frequency compressor speed F and the condenser subcooling degree SC; Table 5 is the fifth preset database between the fifth gain coefficient k3 and the variable frequency compressor suction pressure LP and the evaporator superheat degree SH, where i represents the i-th segment and j represents the number of the linear cooling rate V or the variable frequency compressor speed F or the variable frequency compressor suction pressure LP.

[0106] Table 3. Third Preset Database

[0107]

[0108]

[0109] Table 4. Fourth Preset Database

[0110] <![CDATA[SC1]]> <![CDATA[SC2]]> … <![CDATA[SC i ]]> <![CDATA[F1]]> <![CDATA[k 2_11 ]]> <![CDATA[k 2_12 ]]> … <![CDATA[k 2_1j ]]> <![CDATA[F2]]> <![CDATA[k 2_21 ]]> <![CDATA[k 2_22 ]]> … <![CDATA[k 2_2j ]]> … … … … … <![CDATA[F j ]]> <![CDATA[k 2_i1 ]]> <![CDATA[k 2_i2 ]]> … <![CDATA[k 2_ij ]]>

[0111] Table 5. Fifth Preset Database

[0112] SH1 SH2 … SHi <![CDATA[LP1]]> <![CDATA[k 3_11 ]]> <![CDATA[k 3_12 ]]> … <![CDATA[k 3_1j ]]> <![CDATA[LP2]]> <![CDATA[k 3_21 ]]> <![CDATA[k 3_22 ]]> … <![CDATA[k 3_2j ]]> … … … … … <![CDATA[LP j ]]> <![CDATA[k 3_i1 ]]> <![CDATA[k 3_i2 ]]> … <![CDATA[k 3_ij ]]>

[0113] S53, establish a sixth preset database between the sixth gain coefficient and the opening degree of the electronic expansion valve and the segmented starting temperature, and establish a seventh preset database between the seventh gain coefficient and the suction pressure of the variable frequency compressor and the superheat of the evaporator. The sixth gain coefficient and the seventh gain coefficient are both control gain coefficients of the evaporator fan speed.

[0114] For example, see Tables 6 and 7, Table 6 shows the relationship between the sixth gain coefficient r1 and the electronic expansion valve opening E, and the segment start temperature (T0). i The sixth preset database between; Table 7 is the seventh preset database between the seventh gain coefficient r2 and the variable frequency compressor suction pressure LP and the evaporator superheat SH, where i represents the i-th segment and j represents the electronic expansion valve opening E or the variable frequency compressor suction pressure LP number.

[0115] Table 6. Sixth Preset Database

[0116] <![CDATA[(T0)1]]> <![CDATA[(T0)2]]> … <![CDATA[(T0) i ]]> <![CDATA[E1]]> <![CDATA[r 1_11 ]]> <![CDATA[r 1_12 ]]> … <![CDATA[r 1_1j ]]> <![CDATA[E2]]> <![CDATA[r 1_21 ]]> <![CDATA[r 1_22 ]]> … <![CDATA[r 1_2j ]]> … … … … … <![CDATA[E j ]]> <![CDATA[r 1_i1 ]]> <![CDATA[r 1_i2 ]]> … <![CDATA[r 1_ij ]]>

[0117] Table 7. Seventh Preset Database

[0118] <![CDATA[SH1]]> <![CDATA[SH2]]> … <![CDATA[SH i ]]> <![CDATA[LP1]]> <![CDATA[r 2_11 ]]> <![CDATA[r 2_12 ]]> … <![CDATA[r 2_1j ]]> <![CDATA[LP2]]> <![CDATA[r 2_21 ]]> <![CDATA[r 2_22 ]]> … <![CDATA[r 2_2j ]]> … … … … … <![CDATA[LP i ]]> <![CDATA[r 2_i1 ]]> <![CDATA[r 2_i2 ]]> … <![CDATA[r 2_ij ]]>

[0119] S54, establish an eighth preset database between the eighth gain coefficient and the discharge pressure of the variable frequency compressor and the subcooling degree of the condenser, and establish a ninth preset database between the ninth gain coefficient and the speed of the variable frequency compressor and the segment start temperature. The eighth gain coefficient and the ninth gain coefficient are both control gain coefficients of the condenser fan speed.

[0120] For example, see Tables 8 and 9. Table 8 is the eighth preset database relating the eighth gain coefficient p1 to the compressor discharge pressure HP and the condenser subcooling degree SC; Table 9 is the database relating the ninth gain coefficient p2 to the compressor speed F and the segment start temperature (T0). i The ninth preset database between, where i represents the i-th segment and j represents the number of the compressor discharge pressure HP or compressor speed F.

[0121] Table 8. Eighth Preset Database

[0122]

[0123]

[0124] Table 9. Ninth Preset Database

[0125] <![CDATA[(T0)1]]> <![CDATA[(T0)2]]> … <![CDATA[(T0) i ]]> <![CDATA[F1]]> <![CDATA[p 2_11 ]]> <![CDATA[p 2_12 ]]> … <![CDATA[p 2_1j <!-- 9 -->]]> <![CDATA[F2]]> <![CDATA[p 2_21 ]]> <![CDATA[p 2_22 ]]> … <![CDATA[p 2_2j ]]> … … … … … <![CDATA[F j ]]> <![CDATA[p 2_i1 ]]> <![CDATA[p 2_i2 ]]> … <![CDATA[p 2_ij ]]>

[0126] In this embodiment of the invention, by using the cooling control method of the test chamber provided in this embodiment of the invention, the speed of the variable frequency compressor and the opening of the electronic expansion valve can be accurately calculated, so that the cooling capacity of the variable frequency compressor matches the required cooling capacity and reduces the energy consumption of the system; at the same time, the speed of the evaporator fan and the speed of the condenser fan can also be accurately calculated, which can reduce the energy consumption of the fans and improve the operational reliability of the system.

[0127] Figure 2 This is a structural diagram of a test chamber provided in an embodiment of the present invention.

[0128] This invention also provides a test chamber, which includes a chamber body, a control system, and a refrigeration system. The control system executes the cooling control method of the test chamber in any of the above embodiments.

[0129] 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.

[0130] The refrigeration system is located inside the cabinet and includes a variable frequency compressor 1, a condenser 2, a condenser fan 3, an evaporator 4, an evaporator fan 5, and an electronic expansion valve 6.

[0131] like Figure 2 As shown, the evaporator 4, electronic expansion valve 6, condenser 2 and variable frequency compressor 1 are connected in series to form a circuit. The condenser fan 3 is located at the condenser 2 and the evaporator fan 5 is located at the evaporator 4.

[0132] Optionally, the sensor unit includes an internal temperature sensor 7, an evaporator outlet temperature sensor 8, a variable frequency compressor suction pressure sensor 9, a variable frequency compressor discharge pressure sensor 10, and a condenser liquid supply temperature sensor 11.

[0133] like Figure 2 As shown, the internal temperature sensor 7 is installed inside the chamber;

[0134] Evaporator outlet temperature sensor 8 is located at the outlet of evaporator 4;

[0135] The variable frequency compressor suction pressure sensor 9 is located at the intake port of the variable frequency compressor 1, and the variable frequency compressor discharge pressure sensor 10 is located at the discharge port of the variable frequency compressor 1.

[0136] The condenser liquid supply temperature sensor 11 is installed at the liquid supply port of the condenser 2.

[0137] Optionally, the control unit includes an evaporator fan speed control module 12, a variable frequency compressor speed control module 13, an electronic expansion valve opening control module 14, a condenser fan speed control module 15, and a data acquisition and calculation control module 16.

[0138] The data acquisition and calculation control module 16 is electrically connected to the sensors in the sensor unit, the evaporator fan speed control module 12, the variable frequency compressor speed control module 13, the electronic expansion valve opening control module 14, and the condenser fan speed control module 15, respectively.

[0139] The evaporator fan speed control module 12 is electrically connected to the evaporator fan 5;

[0140] The variable frequency compressor speed control module 13 is electrically connected to the variable frequency compressor 1;

[0141] The electronic expansion valve opening control module 14 is electrically connected to the electronic expansion valve 6;

[0142] The condenser fan speed control module 15 is electrically connected to the condenser fan 3.

[0143] Specifically, the data acquisition and calculation control module 16 is used to divide the set parameters of the test chamber into a set number of segments, calculate the reference increment of each set parameter in each segment, determine the target control value of each set parameter in different segments based on each reference increment and the control gain coefficient of each set parameter, generate corresponding control commands based on the target control values ​​of each set parameter in different segments, and transmit the corresponding control commands to the evaporator fan speed control module 12, the variable frequency compressor speed control module 13, the electronic expansion valve opening control module 14, and the condenser fan speed control module 15, so that the evaporator fan speed control module 12, the variable frequency compressor speed control module 13, the electronic expansion valve opening control module 14, and the condenser fan speed control module 15 control the evaporator fan 5, the variable frequency compressor 1, the electronic expansion valve 6, and the condenser stage 3 of the test chamber to perform corresponding actions, thereby realizing the linear cooling control of the test chamber with high reliability and low operating energy consumption.

[0144] The test chamber provided in this embodiment of the invention uses the cooling control method of the test chamber in the above embodiment. Therefore, the 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.

[0145] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0146] Finally, it should be noted that the above are merely preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for controlling the cooling of a test chamber, characterized in that, The cooling control method includes: The test chamber's set parameters are divided into a set number of segments, wherein the set parameters include at least the variable frequency compressor speed, electronic expansion valve opening, evaporator fan speed, and condenser fan speed. Calculate the baseline increment of each set parameter within each segment; The target control value of each set parameter in different segments is determined based on each of the benchmark increments and the control gain coefficients of each set parameter. The control gain coefficients of each set parameter are obtained by querying a preset database, which stores the control gain coefficients corresponding to each set parameter determined based on the influence factors of each set parameter in the test chamber. Based on the target control values ​​of each set parameter in different segments, the set parameters in the corresponding segments are adjusted to control the cooling of the test chamber; The method for establishing the preset database includes: The linear cooling rate of the test chamber is determined based on preset temperature parameters, wherein the preset temperature parameters include at least the set starting temperature, the set target temperature, and the target cooling time of the test chamber; The cooling section is divided into a set number of segments, and the starting temperature of each segment is calculated. Obtain the equipment operating parameters of the test chamber, wherein the equipment operating parameters include at least the variable frequency compressor suction pressure, variable frequency compressor discharge pressure, condensing temperature, condenser liquid supply temperature, evaporation temperature, and evaporator outlet temperature; The state parameters of the test chamber are calculated based on the equipment operating parameters, wherein the state parameters include at least the compression ratio of the variable frequency compressor, the subcooling degree of the condenser, and the superheating degree of the evaporator; The preset database is established by using the linear cooling rate, the segmented starting temperature, the equipment operating parameters, and the state parameters as influencing factors of the set parameters. The establishment of the preset database, using the linear cooling rate, the segmented starting temperature, the equipment operating parameters, and the state parameters as influencing factors of the set parameters, includes: A first preset database is established between the first gain coefficient and the linear cooling rate and the segmented starting temperature, and a second preset database is established between the second gain coefficient and the compression ratio of the variable frequency compressor and the subcooling degree of the condenser, wherein the first gain coefficient and the second gain coefficient are both control gain coefficients of the variable frequency compressor speed; A third preset database is established between the third gain coefficient and the linear cooling rate and the segmented starting temperature; a fourth preset database is established between the fourth gain coefficient and the variable frequency compressor speed and the condenser subcooling degree; and a fifth preset database is established between the fifth gain coefficient and the variable frequency compressor suction pressure and the evaporator superheat degree. The third gain coefficient, the fourth gain coefficient and the fifth gain coefficient are all control gain coefficients of the electronic expansion valve opening degree. A sixth preset database is established between the sixth gain coefficient and the opening degree of the electronic expansion valve and the segmented starting temperature. A seventh preset database is established between the seventh gain coefficient and the suction pressure of the variable frequency compressor and the superheat of the evaporator. The sixth gain coefficient and the seventh gain coefficient are both control gain coefficients of the evaporator fan speed. An eighth preset database is established between the eighth gain coefficient and the discharge pressure of the variable frequency compressor and the subcooling degree of the condenser; a ninth preset database is established between the ninth gain coefficient and the speed of the variable frequency compressor and the segmented starting temperature; wherein the eighth gain coefficient and the ninth gain coefficient are both control gain coefficients of the condenser fan speed. Determining the target control value of each set parameter in different segments based on each of the aforementioned benchmark increments and the control gain coefficient of each of the aforementioned set parameters includes: Based on formula Determine the rotational speed of the variable frequency compressor within different segments, wherein 0 ≤ w 1+ w 2≤ M , F Δ is the rotational speed of the variable frequency compressor. f This is the reference increment for the compressor speed. w 1 represents the first gain coefficient. w 2 represents the second gain coefficient. M The number of speed segments for the variable frequency compressor; Based on formula Determine the opening degree of the electronic expansion valve within different segments, where 0 ≤ k 1+ k 2+ k 3≤ A , E The opening degree of the electronic expansion valve, △ e This is the reference increment for the opening degree of the electronic expansion valve. k 1 represents the third gain coefficient. k 2 represents the fourth gain coefficient. k 2 represents the fifth gain coefficient. A The number of segments for the opening of the electronic expansion valve; Based on formula Determine the evaporator fan speed in different segments, where 0 ≤ r 1+ r 2≤ B , H The evaporator fan speed is Δ. h This is the base increment for the evaporator fan speed. r 1 represents the sixth gain coefficient. r 2 represents the seventh gain coefficient. B The number of speed segments for the evaporator fan; Based on formula Determine the condenser fan speed in different segments, where 0 ≤ p 1+ p 2≤ C , D The condenser fan speed is Δ. d This is the base increment for the condenser fan speed. p 1 represents the eighth gain coefficient. p 2 represents the ninth gain coefficient. C This refers to the number of speed segments for the condenser fan.

2. The cooling control method for the test chamber according to claim 1, characterized in that, Calculating the baseline increment of each set parameter within each segment includes: Based on formula Calculate the reference increment of the compressor speed, where Δ f This is the reference increment for the compressor speed. F max This is the maximum speed of the variable frequency compressor. F min This is the minimum speed of the variable frequency compressor. M The number of speed segments for the variable frequency compressor; Based on formula Calculate the reference increment of the compressor speed, where Δ e This is the reference increment for the opening degree of the electronic expansion valve. E max This represents the maximum opening degree of the electronic expansion valve. E min This represents the minimum opening degree of the electronic expansion valve. A The number of segments for the opening of the electronic expansion valve; Based on formula Calculate the base increment of the evaporator fan speed, where Δ h This is the base increment for the evaporator fan speed. H max This is the maximum speed of the evaporator fan. H min This is the minimum speed of the evaporator fan. B The number of speed segments for the evaporator fan; Based on formula Calculate the base increment of the condenser fan speed, where Δ d This is the base increment for the condenser fan speed. D max This is the maximum speed of the condenser fan. D min This is the minimum speed of the condenser fan. C This refers to the number of speed segments for the condenser fan.

3. The cooling control method for the test chamber according to claim 1, characterized in that, The cooling section is divided into a set number of segments, and the starting temperature of each segment is calculated, including: Divide the cooling section into equal parts n Each segment is used with a formula. Calculate the initial temperature of each segment; in, i =1, 2, ..., n , n The number of segments in the cooling section. i express n The first segment in the segment i Each segment T 0 represents the initial temperature of the segment. V The linear cooling rate is denoted as t, and the target cooling time is t.

4. The cooling control method for the test chamber according to claim 1, characterized in that, Calculating the state parameters of the test chamber based on the state parameters includes: The compression ratio of the variable frequency compressor is obtained by comparing the discharge pressure of the variable frequency compressor with the intake pressure of the variable frequency compressor. The condenser subcooling is obtained by subtracting the condensation temperature from the condenser supply temperature. The evaporator superheat is obtained by subtracting the evaporator outlet temperature from the evaporation temperature.

5. A test chamber, characterized in that, The test chamber includes a chamber body, a control system, and a refrigeration system, wherein the control system executes the cooling control method of the 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 enclosure 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. The condenser fan is located at the condenser, and the evaporator fan is located at the evaporator.

6. The test chamber according to claim 5, characterized in that, The sensor unit includes an internal temperature sensor, an evaporator outlet temperature sensor, a variable frequency compressor suction pressure sensor, a variable frequency compressor discharge pressure sensor, and a condenser liquid supply temperature sensor. The temperature sensor inside the box is installed inside the box. The evaporator outlet temperature sensor is located at the outlet of the evaporator. The variable frequency compressor suction pressure sensor is located at the intake port of the variable frequency compressor, and the variable frequency compressor discharge pressure sensor is located at the discharge port of the variable frequency compressor. The condenser liquid supply temperature sensor is located at the liquid supply port of the condenser.

7. The test chamber according to claim 5, characterized in that, 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, calculation, and control module is electrically connected to the sensors in the sensor unit, the evaporator fan speed control module, the variable frequency compressor speed control module, the electronic expansion valve opening control module, and the condenser fan speed control module, respectively. The evaporator fan speed control module is electrically connected to the evaporator fan. The variable frequency compressor speed control module is electrically connected to the variable frequency compressor. The electronic expansion valve opening control module is electrically connected to the electronic expansion valve. The condenser fan speed control module is electrically connected to the condenser fan.

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