Low-temperature humidity control method for automobile environment test chamber

Abstract

The invention discloses a low-temperature humidity control method for an automobile environment test chamber, which relates to the technical field of low-temperature humidity control, and comprises the following steps: calculating an initial temperature difference value and an initial humidity difference value, and determining an initial adjustment strategy of the automobile environment test chamber; after the automobile environment test chamber begins to be adjusted, the adjusted real-time relative humidity is converted into adjusted real-time absolute humidity, a standard reaching prediction model is built, the absolute humidity standard reaching time and the temperature 0 DEG C time are predicted, and a first control strategy of the automobile environment test chamber is set; determining refrigeration maintaining power and refrigeration maintaining time; the humidification maintaining power and the humidification maintaining time are determined; and the refrigerating machine and the humidifier operate alternately and periodically. The operation time and power of the refrigerating machine and the humidifier can be accurately controlled, unnecessary energy consumption is avoided, cross operation can be achieved through an automatic control system, and manual intervention and operation difficulty are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of low-temperature humidity control, and in particular to a low-temperature humidity control method for an automobile environmental test chamber. Background Art

[0002] In the context of the rapid development of the automobile industry, the performance and reliability of automobiles have become the focus of common concern for manufacturers and consumers. In order to ensure the normal operation of automobiles under various extreme climatic conditions, especially the stability and durability under low temperature environments, the low temperature humidity control technology of automobile environmental test chambers is particularly important. In the prior art, the humidity control of automobile environmental test chambers under low temperature conditions often faces many challenges. The traditional method is usually to reduce the temperature through the refrigeration system and adjust the humidity by humidification or dehumidification equipment. However, this method has obvious limitations in low temperature environments. First, when the refrigeration system is running at low temperature, it is difficult to accurately control the temperature in the cabin due to the limitation of refrigeration capacity and the influence of cold transfer efficiency, resulting in large temperature fluctuations and affecting the accuracy of the test results. Secondly, humidity regulation and temperature control are often not synchronized, and humidification or dehumidification operations lag behind temperature changes, making it difficult for the humidity in the cabin to quickly reach and stabilize within the target range. In addition, the environmental test chambers in the prior art also have the problem of high energy consumption in low temperature humidity control. The refrigeration system needs to consume a lot of energy to maintain a low temperature environment, and the humidification or dehumidification equipment will also increase additional energy consumption during operation. This not only increases the cost of the test, but also imposes an unnecessary burden on the environment.

[0003] In a Chinese invention application with application publication number CN116973066A, a low-temperature humidity control method for an automotive environmental wind tunnel is disclosed, comprising a wind tunnel and a low-temperature humidity control section, wherein a cryogenic coil is provided in the low-temperature humidity control section; the low-temperature humidity control method comprises feedforward control and closed-loop control, and the opening of a steam regulating valve is determined by obtaining the final value of the wind tunnel humidity and the final value of the low-temperature humidity control section humidity, thereby achieving control of the humidity of the wind tunnel; at the same time, the cryogenic coil is used to control the temperature of fresh air to be consistent with the set temperature of the wind tunnel test, and then the fresh air cooled by the cryogenic coil and humidified with steam is sent into the wind tunnel.

[0004] In the above invention application, rapid coarse adjustment can be performed through the secondary loop to speed up the response speed of the entire control system, while the main loop is fine-tuned to make slight corrections to the humidity control after the coarse adjustment of the secondary loop, thereby achieving precise control of the humidity in the wind tunnel under low temperature environment. However, the control of temperature and humidity still relies on real-time detection and judgment of temperature and humidity, which often leads to lag in adjustment, because it takes a certain amount of time from detection to adjustment to reaching a new stable state. During this period, the temperature and humidity may have deviated from the target range, thereby affecting the accuracy and reliability of the test.

[0005] To this end, the present invention provides a low-temperature humidity control method for an automobile environmental test chamber. Summary of the invention

[0006] 1. Technical issues to be resolved In view of the deficiencies of the prior art, the present invention provides a method for low-temperature humidity control of an automobile environmental test chamber. The present invention determines the initial adjustment strategy of the automobile environmental test chamber by absolute humidity, which can avoid condensation caused by the increase in relative humidity due to the decrease in temperature. The method of adjusting the humidity first and then cooling down has the advantages of avoiding large fluctuations in humidity, optimizing energy consumption, and protecting equipment. During the maintenance stage, the refrigerator and humidifier are operated in a cross-cycle manner. Through the cross-operation, the operating time and power of the refrigerator and humidifier can be accurately controlled to avoid unnecessary energy consumption. In addition, the cross-operation can be achieved through an automated control system, reducing manual intervention and operating difficulty, thereby solving the technical problems recorded in the background technology.

[0007] (II) Technical solution To achieve the above objectives, the present invention is implemented through the following technical solutions: A low temperature humidity control method for an automobile environmental test chamber comprises the following steps: The target temperature Mw Target relative humidity Ms Convert to target absolute humidity Js , and the initial temperature Cw Initial relative humidity at Cs Convert to initial absolute humidity Cj , calculate the initial temperature difference Zc The difference between the initial humidity Zs , determine the initial adjustment strategy for the automotive environmental test chamber; After the automobile environmental test chamber starts to adjust, detect the real-time temperature of the automobile environmental test chamber. and adjust the real-time relative humidity and will adjust the real-time relative humidity Convert to adjust real-time absolute humidity , build a standard prediction model to predict the time when absolute humidity reaches the standard Dsd and temperature 0 degrees time Dws , set the first control strategy of the automotive environmental test chamber; When adjusting the real-time absolute humidity Reach target absolute humidity Js After that, stop the humidifier or dehumidifier and analyze the humidity maintenance rate of the refrigerator at different cooling powers. and humidity to maintain the temperature change rate , calculate the humidity exceeding time for different cooling powers and temperature reaching time , determine the maintenance cooling power And maintain cooling time ; When maintaining cooling power And maintain cooling time After confirmation, the refrigerator runs at maximum power until the humidity in the automotive environmental test chamber maintains the real-time temperature. Reach target temperature Mw , stop the refrigerator and analyze the temperature and humidity change rate of the humidifier at different powers and temperature maintenance temperature change rate , calculate the temperature exceeding time under different humidification power and humidity reaching standard time , determine the maintenance humidification power and maintain humidification time ; After the absolute humidity reaches the standard, the cooling power is maintained And maintain cooling time Control the operation of the refrigerator, and maintain the humidification power after the refrigerator stops running. And maintain humidification time The humidifier operation is controlled to cycle back and forth so that the refrigerator and humidifier can operate in cross cycles.

[0008] Further, get the target temperature Mw , Target relative humidity Ms , initial relative humidity Cs and initial temperature Cw , the target temperature Mw Target relative humidity Ms Convert to target absolute humidity Js , and the initial temperature Cw Initial relative humidity at Cs Convert to initial absolute humidity Cj :

[0009] in, is the gas constant for water vapor, which is approximately 461.5 J / (kg·K).

[0010] Further, get the target temperature Mw , initial temperature Cw , Target absolute humidity Js and initial absolute humidity Cj , calculate the initial temperature difference Zc The difference between the initial humidity Zs :

[0011] When the initial temperature difference Zc When it is greater than 0, the refrigerator is started to cool down, and the initial temperature differenceZc When the initial humidity difference is not greater than 0, the heating tube is started to increase the temperature; Zs When it is greater than 0, the dehumidifier is started for dehumidification, and the initial humidity difference Zs When it is not greater than 0, the humidifier is started for humidification. And the initial starting power is the maximum power.

[0012] Furthermore, after the automobile environmental test chamber begins to adjust, the temperature and humidity sensors are used to periodically detect the real-time temperature of the automobile environmental test chamber. and adjust the real-time relative humidity and will adjust the real-time relative humidity Convert to adjust real-time absolute humidity :

[0013] in, i Indicates changes in the detection time sequence of the reconciliation data.

[0014] Furthermore, the real-time absolute humidity will be adjusted and adjust the real-time temperature The data set is divided into a training set and a test set. A deep learning model is imported to extract time features, change rate and other features. The absolute humidity target threshold and temperature target threshold (i.e. 0) are set. A compliance prediction model is built to predict the humidity or temperature value at a certain point in the future. If the predicted absolute humidity reaches or exceeds the threshold, the current time is recorded as the absolute humidity compliance time. Dsd If the predicted temperature is less than or equal to 0 degrees, the current time is also recorded as the temperature 0 degree time Dws .

[0015] Furthermore, according to the absolute humidity reaching standard time Dsd and the temperature 0 degree time Dws The relationship between the first control strategy of the automotive environmental test chamber is set as follows: When the absolute humidity reaches the standard time Dsd Time below 0 degree temperature Dws , indicating that the absolute humidity meets the standard first, and the real-time absolute humidity Reach target absolute humidity Js After that, the humidifier or dehumidifier is stopped, and the refrigerator or heating tube continues to work until the real-time temperature Reach target temperature; When the absolute humidity reaches the standard time Dsd Not less than 0 degree time Dws , indicating that the temperature reaches 0 degrees first, the power of the refrigerator or heating tube is gradually reduced, the real-time temperature and humidity data are re-tested, and the absolute humidity is predicted to reach the standard time. Dsd and temperature 0 degrees time Dws, until the absolute humidity reaches the standard time Dsd Time below 0 degree temperature Dws , keep the power of the refrigerator or heating tube to adjust the temperature of the automobile environmental test chamber until the real-time absolute humidity is adjusted Reach target absolute humidity Js .

[0016] Furthermore, when adjusting the real-time absolute humidity Reach target absolute humidity Js After that, stop the humidifier or dehumidifier, keep the refrigerator at different cooling powers for the same time T, and use the temperature and humidity sensor to periodically detect the humidity in the automotive environmental test chamber to maintain the real-time temperature. Maintain real-time relative humidity and humidity, and convert the real-time relative humidity to absolute humidity , calculate the humidity maintenance humidity change rate under different cooling power and humidity to maintain the temperature change rate :

[0017] in, j Indicates the detection time sequence number of the humidity maintenance data after humidification is stopped. , k Indicates the number of different cooling powers of the refrigerator, the formula for converting the real-time relative humidity to the absolute humidity and the formula for adjusting the real-time relative humidity Convert to adjust real-time absolute humidity The method is the same.

[0018] Further, obtain the humidity to maintain the humidity change rate , Humidity maintenance temperature change rate , Target temperature Mw and target absolute humidity Js , calculate the humidity exceeding time for different cooling powers and temperature reaching time :

[0019] Get the humidity exceeding the standard time Greater than the temperature reaching time The cooling power with the minimum cooling power is the maintenance cooling power , the corresponding temperature reaching time To maintain cooling time .

[0020] Furthermore, when maintaining cooling power And maintain cooling time After confirmation, the refrigerator runs at maximum power until the humidity in the automotive environmental test chamber maintains the real-time temperature. Reach target temperature Mw , stop the refrigerator, keep the humidifier at different powers for the same time T, and use the temperature and humidity sensor to periodically detect the temperature in the automotive environmental test chamber to maintain the real-time temperature Maintain real-time relative humidity with temperature, and convert the real-time relative humidity maintained with temperature into absolute humidity maintained with temperature , calculate the temperature maintenance humidity change rate under different cooling power and temperature maintenance temperature change rate :

[0021] in, j Indicates the detection time sequence number of the temperature maintenance data after stopping refrigeration. , v Indicates the number of different powers of the humidifier, the formula for converting the temperature-maintained real-time relative humidity into the temperature-maintained absolute humidity and the formula for adjusting the real-time relative humidity Convert to adjust real-time absolute humidity The method is the same as; Get the temperature and humidity change rate , Temperature maintenance temperature change rate , Target temperature Mw and target absolute humidity Js , calculate the temperature exceeding time under different humidification power and humidity reaching standard time :

[0022] Take the temperature exceeding the limit time Greater than humidity reaching standard time The humidification power with the minimum humidification power is the maintenance humidification power. , and its corresponding humidity reaching standard time To maintain humidification time .

[0023] Furthermore, when maintaining the humidification power And maintain humidification time After confirmation, the humidifier runs at maximum power until the temperature in the automotive environmental test chamber maintains the absolute humidity Reach target absolute humidity Js ; After the absolute humidity reaches the standard, the cooling power is maintained And maintain cooling time Control the operation of the refrigerator, and maintain the humidification power after the refrigerator stops running. And maintain humidification time The humidifier operation is controlled to cycle back and forth so that the refrigerator and humidifier can operate in cross cycles.

[0024] (III) Beneficial effects The present invention provides a low temperature humidity control method for an automobile environmental test chamber, which has the following beneficial effects: 1. Set the target temperature Mw Target relative humidity Ms Convert to target absolute humidity Js , and the initial temperature Cw Initial relative humidity at Cs Convert to initial absolute humidity Cj , calculate the initial temperature difference Zc The difference between the initial humidity Zs , determine the initial conditioning strategy for the automotive environmental test chamber. Determining the initial conditioning strategy for the automotive environmental test chamber based on absolute humidity can avoid condensation caused by increased relative humidity due to lower temperature and the need for further dehumidification steps, which helps to shorten test preparation time and improve test efficiency.

[0025] 2. After the automobile environmental test chamber starts to adjust, detect the real-time temperature of the automobile environmental test chamber. and adjust the real-time relative humidity and will adjust the real-time relative humidity Convert to adjust real-time absolute humidity , build a standard prediction model to predict the time when absolute humidity reaches the standard Dsd and temperature 0 degrees time Dws , setting the first control strategy of the automotive environmental test chamber, adjusting the humidity first and then cooling it down has the benefits of avoiding large fluctuations in humidity, optimizing energy consumption, and protecting equipment.

[0026] 3. When adjusting the real-time absolute humidity Reach target absolute humidity Js After that, stop the humidifier or dehumidifier and analyze the humidity maintenance rate of the refrigerator at different cooling powers. and humidity to maintain the temperature change rate , calculate the humidity exceeding time for different cooling powers and temperature reaching time , determine the maintenance cooling power And maintain cooling time By precisely controlling the cooling power and time, unnecessary energy waste can be avoided and energy utilization efficiency can be improved.

[0027] 4. When maintaining cooling power And maintain cooling time After confirmation, the refrigerator runs at maximum power until the humidity in the automotive environmental test chamber maintains the real-time temperature. Reach target temperature Mw , stop the refrigerator and analyze the temperature and humidity change rate of the humidifier at different powers and temperature maintenance temperature change rate , calculate the temperature exceeding time under different humidification power and humidity reaching standard time , determine the maintenance humidification power And maintain humidification time , by precisely controlling the humidification power and time, it can ensure that the humidity in the cabin is stable within the target range, meet the requirements of automotive environmental testing, avoid excessive operation or frequent start and stop of the humidifier, and thus reduce energy consumption.

[0028] 5. Maintain cooling power after absolute humidity reaches the standard And maintain cooling time Control the operation of the refrigerator, and maintain the humidification power after the refrigerator stops running. And maintain humidification time Control the operation of the humidifier, cycle back and forth, and make the refrigerator and humidifier run in cross cycles. Through cross operation, the operating time and power of the refrigerator and humidifier can be accurately controlled to avoid unnecessary energy consumption. Cross operation can be achieved through an automated control system to reduce manual intervention and operational difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a schematic flow chart of a low-temperature humidity control method for an automobile environmental test chamber. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] See also Figure 1 The present invention provides a low temperature humidity control method for an automobile environmental test chamber, comprising the following steps: Step 1: Set the target temperature Mw Target relative humidity Ms Convert to target absolute humidity Js , and the initial temperature Cw Initial relative humidity at Cs Convert to initial absolute humidity Cj, calculate the initial temperature difference Zc The difference between the initial humidity Zs , determine the initial adjustment strategy for the automotive environmental test chamber.

[0032] The step 1 includes the following contents: Step 101: Determine the required target temperature according to the test requirements of the automobile and its parts. Mw and target relative humidity Ms The humidity and temperature sensors in the automotive environmental test chamber are used to detect the initial relative humidity in the chamber. Cs and initial temperature Cw .

[0033] Humidity sensors detect relative humidity, which refers to the ratio between the water vapor content in the air and the saturated water vapor content. It reflects the degree to which the water vapor in the air is close to saturation. The working principle of humidity sensors is usually based on the hygroscopic properties of materials, such as hygroresistors and hygrocapacitors. When these materials are affected by moisture, their conductivity or capacitance changes, so that the corresponding humidity changes can be measured. This change is proportional to the relative humidity, so the humidity sensor can accurately measure the relative humidity in the environment; absolute humidity refers to the mass of water vapor contained in a unit volume of air, which is not affected by temperature. However, humidity sensors do not directly measure absolute humidity, but indirectly reflect the water vapor content in the air by measuring relative humidity.

[0034] Step 102: Get target temperature Mw , Target relative humidity Ms , initial relative humidity Cs and initial temperature Cw , the target temperature Mw Target relative humidity Ms Convert to target absolute humidity Js , and the initial temperature Cw Initial relative humidity at Cs Convert to initial absolute humidity Cj :

[0035] in, is the gas constant for water vapor, which is approximately 461.5 J / (kg·K).

[0036] Step 103: Get target temperature Mw , initial temperature Cw , Target absolute humidity Js and initial absolute humidity Cj , calculate the initial temperature difference Zc The difference between the initial humidity Zs :

[0037] When the initial temperature difference Zc When it is greater than 0, the refrigerator is started to cool down, and the initial temperature difference Zc When the initial humidity difference is not greater than 0, the heating tube is started to increase the temperature; Zs When it is greater than 0, the dehumidifier is started for dehumidification, and the initial humidity difference Zs When it is not greater than 0, the humidifier is started for humidification. And the initial starting power is the maximum power.

[0038] When using, combine the contents in steps 101 to 103: The target temperature Mw Target relative humidity Ms Convert to target absolute humidity Js , and the initial temperature Cw Initial relative humidity at Cs Convert to initial absolute humidity Cj , calculate the initial temperature difference Zc The initial adjustment strategy of the automobile environmental test chamber is determined by the absolute humidity. Condensation caused by the increase in relative humidity due to the decrease in temperature and the need for further dehumidification steps can be avoided, which helps to shorten the test preparation time and improve the test efficiency.

[0039] Step 2: After the car environment test chamber starts to adjust, detect the real-time temperature of the car environment test chamber. and adjust the real-time relative humidity and will adjust the real-time relative humidity Convert to adjust real-time absolute humidity , build a standard prediction model to predict the time when absolute humidity reaches the standard Dsd and temperature 0 degrees time Dws , set the first control strategy for the automotive environmental test chamber.

[0040] The step 2 includes the following contents: Step 201: After the automobile environmental test chamber starts to be adjusted, the temperature and humidity sensors are used to periodically detect the real-time temperature of the automobile environmental test chamber. and adjust the real-time relative humidity and will adjust the real-time relative humidity Convert to adjust real-time absolute humidity :

[0041] in, i Indicates changes in the detection time sequence of the reconciliation data.

[0042] Step 202: Adjust the real-time absolute humidity and adjust the real-time temperature The data set is divided into a training set and a test set. A deep learning model is imported to extract time features, change rate and other features. The absolute humidity target threshold and temperature target threshold (i.e. 0) are set. A compliance prediction model is built to predict the humidity or temperature value at a certain point in the future. If the predicted absolute humidity reaches or exceeds the threshold, the current time is recorded as the absolute humidity compliance time. Dsd If the predicted temperature is less than or equal to 0 degrees, the current time is also recorded as the temperature 0 degree time Dws .

[0043] Step 203: According to the absolute humidity reaching standard time Dsd and temperature 0 degrees time Dws The relationship between the first control strategy of the automotive environmental test chamber is set as follows: When the absolute humidity reaches the standard time Dsd Time below 0 degree temperature Dws , indicating that the absolute humidity meets the standard first, and the real-time absolute humidity Reach target absolute humidity Js After that, the humidifier or dehumidifier is stopped, and the refrigerator or heating tube continues to work until the real-time temperature Reach the target temperature.

[0044] When the absolute humidity reaches the standard time Dsd Not less than 0 degree time Dws , indicating that the temperature reaches 0 degrees first, the power of the refrigerator or heating tube is gradually reduced, the real-time temperature and humidity data are re-tested, and the absolute humidity is predicted to reach the standard time. Dsd and temperature 0 degrees time Dws , until the absolute humidity reaches the standard time Dsd Time below 0 degree temperature Dws , keep the power of the refrigerator or heating tube to adjust the temperature of the automobile environmental test chamber until the real-time absolute humidity is adjusted Reach target absolute humidity Js .

[0045] When using, combine the contents in steps 201 to 203: After the automobile environmental test chamber starts to adjust, detect the real-time temperature of the automobile environmental test chamber. and adjust the real-time relative humidity and will adjust the real-time relative humidity Convert to adjust real-time absolute humidity , build a standard prediction model to predict the time when absolute humidity reaches the standard Dsd and temperature 0 degrees time Dws, setting the first control strategy of the automotive environmental test chamber, adjusting the humidity first and then cooling it down has the benefits of avoiding large fluctuations in humidity, optimizing energy consumption, and protecting equipment.

[0046] Step 3: Adjust the real-time absolute humidity Reach target absolute humidity Js After that, stop the humidifier or dehumidifier and analyze the humidity maintenance rate of the refrigerator at different cooling powers. and humidity to maintain the temperature change rate , calculate the humidity exceeding time for different cooling powers and temperature reaching time , determine the maintenance cooling power And maintain cooling time .

[0047] The step three includes the following contents: Step 301: When adjusting the real-time absolute humidity Reach target absolute humidity Js After that, stop the humidifier or dehumidifier, keep the refrigerator at different cooling powers for the same time T, and use the temperature and humidity sensor to periodically detect the humidity in the automotive environmental test chamber to maintain the real-time temperature. Maintain real-time relative humidity and humidity, and convert the real-time relative humidity to absolute humidity , calculate the humidity maintenance humidity change rate under different cooling power and humidity to maintain the temperature change rate :

[0048] in, j Indicates the detection time sequence number of the humidity maintenance data after humidification is stopped. , k Indicates the number of different cooling powers of the refrigerator, the formula for converting the real-time relative humidity to the absolute humidity and the formula for adjusting the real-time relative humidity Convert to adjust real-time absolute humidity The method is the same.

[0049] Step 302: Obtain humidity and maintain humidity change rate , Humidity maintenance temperature change rate , Target temperature Mw and target absolute humidity Js , calculate the humidity exceeding time for different cooling powers and temperature reaching time :

[0050] Get the humidity exceeding the standard time Greater than the temperature reaching time The cooling power with the minimum cooling power is the maintenance cooling power , the corresponding temperature reaching time To maintain cooling time .

[0051] When used, combine the contents in steps 301 and 302: When adjusting the real-time absolute humidity Reach target absolute humidity Js After that, stop the humidifier or dehumidifier and analyze the humidity maintenance rate of the refrigerator at different cooling powers. and humidity to maintain the temperature change rate , calculate the humidity exceeding time for different cooling powers and temperature reaching time , determine the maintenance cooling power And maintain cooling time By precisely controlling the cooling power and time, unnecessary energy waste can be avoided and energy utilization efficiency can be improved.

[0052] Step 4: Maintain cooling power And maintain cooling time After confirmation, the refrigerator runs at maximum power until the humidity in the automotive environmental test chamber maintains the real-time temperature. Reach target temperature Mw , stop the refrigerator and analyze the temperature and humidity change rate of the humidifier at different powers and temperature maintenance temperature change rate , calculate the temperature exceeding time under different humidification power and humidity reaching standard time , determine the maintenance humidification power And maintain humidification time .

[0053] The step 4 includes the following contents: Step 401: When maintaining cooling power And maintain cooling time After confirmation, the refrigerator runs at maximum power until the humidity in the automotive environmental test chamber maintains the real-time temperature. Reach target temperature Mw , stop the refrigerator, keep the humidifier at different powers for the same time T, and use the temperature and humidity sensor to periodically detect the temperature in the automotive environmental test chamber to maintain the real-time temperature Maintain real-time relative humidity with temperature, and convert the real-time relative humidity maintained with temperature into absolute humidity maintained with temperature , calculate the temperature maintenance humidity change rate under different cooling power and temperature maintenance temperature change rate :

[0054] in, j Indicates the detection time sequence number of the temperature maintenance data after stopping refrigeration. , v Indicates the number of different powers of the humidifier, the formula for converting the temperature-maintained real-time relative humidity into the temperature-maintained absolute humidity and the formula for adjusting the real-time relative humidity Convert to adjust real-time absolute humidity The method is the same.

[0055] Step 402: Obtain temperature and humidity change rate , Temperature maintenance temperature change rate , Target temperature Mw and target absolute humidity Js , calculate the temperature exceeding time under different humidification power and humidity reaching standard time :

[0056] Take the temperature exceeding the limit time Greater than humidity reaching standard time The humidification power with the minimum humidification power is the maintenance humidification power. , and its corresponding humidity reaching standard time To maintain humidification time .

[0057] When using, combine the contents in steps 401 and 402: When maintaining cooling power And maintain cooling time After confirmation, the refrigerator runs at maximum power until the humidity in the automotive environmental test chamber maintains the real-time temperature. Reach target temperature Mw , stop the refrigerator and analyze the temperature and humidity change rate of the humidifier at different powers and temperature maintenance temperature change rate , calculate the temperature exceeding time under different humidification power and humidity reaching standard time , determine the maintenance humidification power And maintain humidification time , by precisely controlling the humidification power and time, it can ensure that the humidity in the cabin is stable within the target range, meet the requirements of automotive environmental testing, avoid excessive operation or frequent start and stop of the humidifier, and thus reduce energy consumption.

[0058] Step 5: Maintain cooling power after absolute humidity reaches the standard And maintain cooling time Control the operation of the refrigerator, and maintain the humidification power after the refrigerator stops running. And maintain humidification time The humidifier operation is controlled to cycle back and forth so that the refrigerator and humidifier can operate in cross cycles.

[0059] The step five includes the following contents: Step 501: When maintaining humidification power And maintain humidification time After confirmation, the humidifier runs at maximum power until the temperature in the automotive environmental test chamber maintains the absolute humidity Reach target absolute humidity Js.

[0060] Step 502: After the absolute humidity reaches the standard, the cooling power is maintained. And maintain cooling time Control the operation of the refrigerator, and maintain the humidification power after the refrigerator stops running. And maintain humidification time The humidifier operation is controlled to cycle back and forth so that the refrigerator and humidifier can operate in cross cycles.

[0061] It should be noted that during the low-temperature humidity control process of the automobile environmental test chamber, the temperature will tend to rise if no temperature adjustment is performed. Therefore, refrigeration is a conventional temperature adjustment method. Refrigeration will lower the humidity in the cabin, so it is only necessary to humidify the cabin.

[0062] When using, combine the contents in steps 501 and 502: After the absolute humidity reaches the standard, the cooling power is maintained And maintain cooling time Control the operation of the refrigerator, and maintain the humidification power after the refrigerator stops running. And maintain humidification time Control the operation of the humidifier, cycle back and forth, and make the refrigerator and humidifier run in cross cycles. Through cross operation, the operating time and power of the refrigerator and humidifier can be accurately controlled to avoid unnecessary energy consumption. Cross operation can be achieved through an automated control system to reduce manual intervention and operational difficulty.

[0063] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product. A person of ordinary skill in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution.

[0064] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0065] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A low temperature humidity control method for an automobile environmental test chamber, characterized in that: The steps include: The target temperature M Target relative humidity Ms Convert to target absolute humidity Js , and the initial temperature C Initial relative humidity at Cs Convert to initial absolute humidity Cj , calculate the initial temperature difference Zc The difference between the initial humidity Z , determine the initial adjustment strategy for the automotive environmental test chamber; After the automobile environmental test chamber starts to adjust, detect the real-time temperature of the automobile environmental test chamber. and adjust the real-time relative humidity and will adjust the real-time relative humidity Convert to adjust real-time absolute humidity , build a standard prediction model to predict the time when absolute humidity reaches the standard Dsd and temperature 0 degrees time Dw , set the first control strategy of the automotive environmental test chamber; When adjusting the real-time absolute humidity Reach target absolute humidity Js After that, stop the humidifier or dehumidifier and analyze the humidity maintenance rate of the refrigerator at different cooling powers. and humidity to maintain the temperature change rate , calculate the humidity exceeding time for different cooling powers and temperature reaching time , determine the maintenance cooling power And maintain cooling time ; When maintaining cooling power And maintain cooling time After confirmation, the refrigerator runs at maximum power until the humidity in the automotive environmental test chamber maintains the real-time temperature. Reach target temperature M , stop the refrigerator and analyze the temperature and humidity change rate of the humidifier at different powers and temperature maintenance temperature change rate , calculate the temperature exceeding time under different humidification power and humidity reaching standard time , determine the maintenance humidification power and maintain humidification time ; After the absolute humidity reaches the standard, the cooling power is maintained And maintain cooling time Control the operation of the refrigerator, and maintain the humidification power after the refrigerator stops running. And maintain humidification time The humidifier operation is controlled to cycle back and forth so that the refrigerator and humidifier can operate in cross cycles.

2. A low temperature humidity control method for an automobile environmental test chamber according to claim 1, characterized in that: Get target temperature M , Target relative humidity Ms , initial relative humidity Cs and initial temperature C , the target temperature M Target relative humidity Ms Convert to target absolute humidity Js , and the initial temperature C Initial relative humidity at Cs Convert to initial absolute humidity Cj : in, is the gas constant for water vapor, which is approximately 461.5 J / (kg·K).

3. A low temperature humidity control method for an automobile environmental test chamber according to claim 1, characterized in that: Get target temperature M , initial temperature C , Target absolute humidity Js and initial absolute humidity Cj , calculate the initial temperature difference Zc The difference between the initial humidity Z : When the initial temperature difference Zc When it is greater than 0, the refrigerator is started to cool down, and the initial temperature difference Zc When it is not greater than 0, the heating tube is started to increase the temperature; When the initial humidity difference Z When it is greater than 0, the dehumidifier is started for dehumidification, and the initial humidity difference Z When it is not greater than 0, start the humidifier to humidify; And the initial starting power is the maximum power.

4. A low temperature humidity control method for an automobile environmental test chamber according to claim 1, characterized in that: After the automotive environmental test chamber begins to adjust, the temperature and humidity sensors are used to periodically detect the real-time temperature of the automotive environmental test chamber. and adjust the real-time relative humidity and will adjust the real-time relative humidity Convert to adjust real-time absolute humidity : in, i Indicates changes in the detection time sequence of the reconciliation data.

5. The low temperature humidity control method for an automobile environmental test chamber according to claim 1, characterized in that: Will adjust the real-time absolute humidity and adjust the real-time temperature The data set is divided into a training set and a test set. A deep learning model is imported to extract time features, change rate and other features. The absolute humidity target threshold and temperature target threshold (i.e. 0) are set. A compliance prediction model is built to predict the humidity or temperature value at a certain point in the future. If the predicted absolute humidity reaches or exceeds the threshold, the current time is recorded as the absolute humidity compliance time. Dsd If the predicted temperature is less than or equal to 0 degrees, the current time is also recorded as the temperature 0 degree time Dw .

6. A low temperature humidity control method for an automobile environmental test chamber according to claim 1, characterized in that: According to the absolute humidity reaching time Dsd and temperature 0 degrees time Dw The relationship between the first control strategy of the automotive environmental test chamber is set as follows: When the absolute humidity reaches the standard time Dsd Time below 0 degree temperature Dw , indicating that the absolute humidity meets the standard first, and the real-time absolute humidity Reach target absolute humidity Js After that, the humidifier or dehumidifier is stopped, and the refrigerator or heating tube continues to work until the real-time temperature Reach target temperature; When the absolute humidity reaches the standard time Dsd Not less than 0 degree time Dw , indicating that the temperature reaches 0 degrees first, the power of the refrigerator or heating tube is gradually reduced, the real-time temperature and humidity data are re-tested, and the absolute humidity is predicted to reach the standard time. Dsd and temperature 0 degrees time Dw , until the absolute humidity reaches the standard time Dsd Time below 0 degree temperature Dw , keep the power of the refrigerator or heating tube to adjust the temperature of the automobile environmental test chamber until the real-time absolute humidity is adjusted Reach target absolute humidity Js .

7. The low temperature humidity control method for an automobile environmental test chamber according to claim 1, characterized in that: When adjusting the real-time absolute humidity Reach target absolute humidity Js After that, stop the humidifier or dehumidifier, keep the refrigerator at different cooling powers for the same time T, and use the temperature and humidity sensor to periodically detect the humidity in the automotive environmental test chamber to maintain the real-time temperature. Maintain real-time relative humidity and humidity, and convert the real-time relative humidity to absolute humidity , calculate the humidity maintenance humidity change rate under different cooling power and humidity to maintain the temperature change rate : in, j Indicates the detection time sequence number of the humidity maintenance data after humidification is stopped. , k Indicates the number of different cooling powers of the refrigerator, the formula for converting the real-time relative humidity to the absolute humidity and the formula for adjusting the real-time relative humidity Convert to adjust real-time absolute humidity The method is the same.

8. The low temperature humidity control method for an automobile environmental test chamber according to claim 1, characterized in that: Get humidity and maintain humidity change rate , Humidity maintenance temperature change rate , Target temperature M and target absolute humidity Js , calculate the humidity exceeding time for different cooling powers and temperature reaching time : Get the humidity exceeding the standard time Greater than the temperature reaching time The cooling power with the minimum cooling power is the maintenance cooling power , the corresponding temperature reaching time To maintain cooling time .

9. The low temperature humidity control method for an automobile environmental test chamber according to claim 1, characterized in that: When maintaining cooling power And maintain cooling time After confirmation, the refrigerator runs at maximum power until the humidity in the automotive environmental test chamber maintains the real-time temperature. Reach target temperature M , stop the refrigerator, keep the humidifier at different powers for the same time T, and use the temperature and humidity sensor to periodically detect the temperature in the automotive environmental test chamber to maintain the real-time temperature Maintain real-time relative humidity with temperature, and convert the real-time relative humidity maintained with temperature into absolute humidity maintained with temperature , calculate the temperature maintenance humidity change rate under different cooling power and temperature maintenance temperature change rate : in, j Indicates the detection time sequence number of the temperature maintenance data after stopping refrigeration. , v Indicates the number of different powers of the humidifier, the formula for converting the temperature-maintained real-time relative humidity into the temperature-maintained absolute humidity and the formula for adjusting the real-time relative humidity Convert to adjust real-time absolute humidity The method is the same as; Get the temperature and humidity change rate , Temperature maintenance temperature change rate , Target temperature M and target absolute humidity Js , calculate the temperature exceeding time under different humidification power and humidity reaching standard time : Take the temperature exceeding the limit time Greater than humidity reaching standard time The humidification power with the minimum humidification power is the maintenance humidification power. , and its corresponding humidity reaching standard time To maintain humidification time .

10. The low temperature humidity control method for an automobile environmental test chamber according to claim 1, characterized in that: When maintaining humidification power And maintain humidification time After confirmation, the humidifier runs at maximum power until the temperature in the automotive environmental test chamber maintains the absolute humidity Reach target absolute humidity Js ; After the absolute humidity reaches the standard, the cooling power is maintained And maintain cooling time Control the operation of the refrigerator, and maintain the humidification power after the refrigerator stops running. And maintain humidification time The humidifier operation is controlled to cycle back and forth so that the refrigerator and humidifier can operate in cross cycles.

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