Energy-saving operation method of automobile environmental wind tunnel

Abstract

The present invention relates to the technical field of wind tunnel energy-saving operation, and discloses an energy-saving operation method for a wind tunnel in an automobile environment, comprising: judging whether the wind tunnel is in a preparation mode; when the wind tunnel is in the preparation mode, determining the difference between a set temperature of the wind tunnel and an actual temperature of the wind tunnel; if the difference between the set temperature and the actual temperature exceeds a first threshold range, judging whether the set temperature is greater than the actual temperature; if so, shutting down a fresh air humidity control system, a cryogenic system, and an exhaust system, and starting a heating system; if less than, shutting down the heating system, and starting the fresh air humidity control system, the cryogenic system, and the exhaust system; judging whether the set temperature is greater than a second threshold; if so, controlling some cryogenic units in the cryogenic system to operate, and starting the fresh air humidity control system, the heating system, and the exhaust system; if less than or equal to, starting the fresh air humidity control system, the heating system, the exhaust system, and the entire cryogenic system; so as to solve the problem that the existing wind tunnel operation mode is not energy-efficient.

Description

Technical Field

[0001] The present invention relates to the technical field of wind tunnel energy-saving operation, and in particular to an energy-saving operation method of a wind tunnel in an automobile environment. Background Art

[0002] The automotive environmental wind tunnel is a crucial testing laboratory in automotive R&D, simulating real-world climates to test vehicle performance. The tunnel is equipped with an automated control system, including a fresh air humidity control system, a heating system, a cryogenic cooling system, and an exhaust system. The cryogenic cooling system includes multiple cryogenic units, while the fresh air humidity control system includes a dehumidification section, a high-flow section, and a low-flow section. These systems simulate temperatures within the tunnel from -40°C to 60°C, humidity from 5% to 95% relative humidity, and wind speeds from 0 to 200 km / h. Rain, snow, and sunlight can also be simulated simultaneously. Furthermore, a rotating drum is installed on the tunnel's floor. Its operation enables dynamic testing of vehicles in the tunnel and road simulations, ensuring that the resistance experienced by the vehicle on the drum is consistent with that encountered on a real road.

[0003] While providing excellent temperature, humidity, light, rain and snow simulation, automotive environmental wind tunnels also consume a large amount of energy. A month's operation costs approximately 600,000 yuan in electricity, 200,000 yuan in gas, and 10,000 yuan in water. The high cost of operation makes reducing energy consumption and lowering costs a common challenge faced by all automotive environmental wind tunnels.

[0004] At present, there is no effective energy-saving operation method for various automotive environmental wind tunnels. This is mainly due to the complex simulation environment of wind tunnel tests. In order to ensure the accuracy of test results, as long as the automotive environmental wind tunnel is started, all subsystems will automatically start and run. For example, the temperature control system will deviate from time to time during the test due to variable test conditions and other reasons. This deviation will fluctuate between positive and negative deviations. Heating is required when the deviation is positive, and cooling is required when the deviation is negative. Therefore, the cryogenic system, fresh air humidity control system, and tail exhaust system need to be turned on at the same time, and all cryogenic units in the cryogenic system will be started at the same time. In the fresh air humidity control system, the dehumidifier and heat exchanger in the dehumidification section, and the steam heater and heat exchanger in the large flow section will all be turned on together. Although this operation method can meet the test needs of automotive environmental wind tunnels, the operating costs will also increase, resulting in non-energy-saving operation of the wind tunnel. Summary of the Invention

[0005] The present invention aims to provide an energy-saving operation method for an automobile environmental wind tunnel, so as to solve the problem that the existing wind tunnel operation mode is not energy-efficient.

[0006] To achieve the above-mentioned object, the present invention adopts the following technical solution: a method for energy-saving operation of an automobile environmental wind tunnel, applied to an automobile environmental wind tunnel automatic control system, comprising the following steps:

[0007] S1, determine whether the wind tunnel is in preparation mode;

[0008] S2, when the wind tunnel is in a preparation mode, determining a difference between a set temperature of the wind tunnel and an actual temperature of the wind tunnel;

[0009] S3: If the difference between the set temperature and the actual temperature exceeds the first threshold range, determine whether the set temperature is greater than the actual temperature; if so, shut down the fresh air humidity control system, the cryogenic system, and the exhaust system, and start the heating system; if less than, shut down the heating system, and start the fresh air humidity control system, the cryogenic system, and the exhaust system;

[0010] S4, determining whether the current set temperature inside the wind tunnel is equal to the actual temperature;

[0011] S5, determine whether the set temperature is greater than the second threshold value. If it is greater, control some cryogenic units in the cryogenic system to work, and start the fresh air humidity control system, heating system and tail exhaust system; if it is less than or equal to, start the fresh air humidity control system, heating system, tail exhaust system and the entire cryogenic system.

[0012] The beneficial effect of this solution is that by reasonably controlling the start and stop of each subsystem in the automatic control system, while ensuring that the automotive environmental wind tunnel meets the various environmental simulation requirements required for automotive testing, the goal of reducing the wind tunnel operating costs is achieved and energy-saving operation of the wind tunnel is realized.

[0013] During the entire automotive wind tunnel operation, preparation mode occupies a significant portion of the operating time. This is especially true when the wind tunnel test switches from ultra-low temperature to ultra-high temperature, or vice versa. Adjusting the actual temperature in the wind tunnel to the set temperature required for the wind tunnel test requires a relatively long period of system operation. During this period, formal automotive testing has not yet begun, making it an opportune time for energy-saving operation. By setting a first threshold to determine when the actual temperature in the wind tunnel reaches the set temperature, a series of energy-saving operation methods in preparation mode are initiated, saving energy while maintaining normal wind tunnel testing.

[0014] 2. When the difference exceeds the first threshold and the set temperature is greater than the actual temperature, the wind tunnel needs to be heated. Therefore, the cryogenic system, the fresh air humidity control system, and the exhaust system are shut down, and the heating system is activated, thereby reducing system operation and achieving energy conservation. Furthermore, shutting down the fresh air humidity control system and exhaust system during this process not only avoids the problem of activating the fresh air humidity control system and exhaust system for humidity control from the outset, which would consume a large amount of electricity and steam and increase operating costs, but also prevents the glass temperature of the solar simulation system from falling below the ambient temperature inside the wind tunnel during the wind tunnel heating process. This could cause steam to enter the humidity control wind tunnel, resulting in condensation on the glass surface and a high risk of cracking after the solar simulation system is activated.

[0015] 3. When the difference exceeds the first threshold range and the set temperature is less than the actual temperature, it indicates that the wind tunnel needs to be cooled. Therefore, there is no need to start the heating system, but the fresh air humidity control system and the tail exhaust system need to be turned on for humidity control, and the entire cryogenic system needs to be turned on for rapid cooling. Turning off the heating system will save energy. In addition, since the wind tunnel needs to be dehumidified during the cooling process, this prevents condensation when the air temperature inside the wind tunnel drops below the air dew point temperature during the cooling process. Condensed water will adhere to the surfaces of various equipment inside the wind tunnel, causing equipment shutdown or damage.

[0016] 4. When the actual temperature equals the set temperature, the wind tunnel enters test mode. To further improve energy conservation, the test set temperature is then determined to be greater than a second threshold. If it is, the set temperature is relatively high, and the cooling capacity provided by some cryogenic units in the cryogenic system is sufficient to stabilize the set temperature during the test, thus achieving energy conservation. If it is less than or equal to the set temperature, the set temperature is relatively low, and a large amount of cooling capacity is required to stabilize the set temperature inside the wind tunnel. Therefore, the new air humidity control system, heating system, exhaust system, and the entire cryogenic system need to be activated to ensure the accuracy of the wind tunnel test under energy conservation.

[0017] Preferably, in S3, if the difference between the set temperature and the actual temperature is within the first threshold range, it is determined whether the set temperature is greater than the second threshold. If it is greater, some cryogenic units in the cryogenic system are controlled to operate, and the fresh air humidity control system, heating system and tail exhaust system are started; if it is less than or equal to, the fresh air humidity control system, heating system, tail exhaust system and the entire cryogenic system are started.

[0018] The beneficial effect of this solution is that if the difference is within the first threshold range, it indicates that the gap between the actual temperature and the set temperature is not large, and it will not take too long for the actual temperature inside the wind tunnel to reach the set temperature. Therefore, there is no need to start and stop different subsystems in the preparation mode, and operation can be directly carried out by judging whether the set temperature is greater than the second threshold.

[0019] Preferably, in S2, the wind tunnel is not in the preparation mode, indicating that the wind tunnel is in the test mode; it is determined whether the set temperature is greater than the second threshold value. If it is greater than, some cryogenic units in the cryogenic system are controlled to work, and the fresh air humidity control system, heating system and tail exhaust system are started; if it is less than or equal to, the fresh air humidity control system, heating system, tail exhaust system and the entire cryogenic system are started.

[0020] The beneficial effects of this solution are: in the test mode, if the set temperature is greater than the second threshold value, it indicates that the set temperature is relatively high, and the cooling capacity provided by the operation of some cryogenic units in the cryogenic system is sufficient to meet the amount required to stabilize the set temperature during the test. At the same time, the fresh air humidity control system, heating system and tail exhaust system are used to ensure that the system can heat up, cool down or dehumidify and humidify in time according to the detected deviation to ensure the accuracy of the vehicle test results; if it is less than or equal to, it indicates that the set temperature is relatively low at this time. In order to stabilize the set temperature inside the wind tunnel, the cooling capacity generated by some cryogenic units is insufficient, and all cryogenic units need to be turned on. Therefore, all subsystems need to be started to ensure the accuracy of the test.

[0021] Preferably, the first threshold range is between -20°C and 20°C.

[0022] The beneficial effect of this solution is: based on the experience of operating wind tunnels, when the difference between the set temperature and the actual temperature is less than 20°C, it indicates that the time required to adjust the actual temperature to the set temperature is relatively short, and the energy-saving effect of controlling the start and stop of the heating system and the deep cooling system during this period is not obvious.

[0023] Preferably, the second threshold is 5°C.

[0024] The beneficial effects of this solution are as follows: based on actual wind tunnel operation experience, when the test set temperature inside the wind tunnel is greater than 5°C, some cryogenic units in the cryogenic system are started, and the cooling capacity provided by them can meet the effect of stabilizing the set temperature during the test. When the set temperature is below 5°C, all cryogenic units in the cryogenic system need to be started to achieve the effect of stabilizing the set temperature.

[0025] Preferably, the fresh air humidity control system is provided with an energy-saving control mode, which includes the following steps:

[0026] S1-1, determine whether the set temperature is greater than 0℃;

[0027] S2-1, if the set temperature is greater than 0°C, determine the wind tunnel set dew point temperature at the wind tunnel set humidity and set temperature;

[0028] S3-1, if the wind tunnel set dew point temperature is greater than 0℃, enter the humidity control mode and determine whether the fresh air dew point temperature is greater than the wind tunnel set dew point temperature;

[0029] S4-1, if the fresh air dew point temperature is greater than the wind tunnel set dew point temperature, control the dehumidifier dehumidification dew point temperature to be equal to the wind tunnel set dew point temperature minus 10℃;

[0030] S5-1, control the fresh air temperature in the dehumidification section and the large flow section to be equal to the set temperature plus 10℃.

[0031] The beneficial effects of this solution are as follows: In the existing fresh air humidity control system, the temperature of the fresh air needs to be lowered before the dehumidification operation is performed. However, 60% of the wind tunnel tests are conducted at high temperatures and high humidity. In this case, the temperature set in the wind tunnel test is higher than the fresh air temperature. Therefore, the cooling operation will waste a lot of electricity and steam, resulting in excessively high wind tunnel operation costs. The energy-saving control mode first determines whether the set temperature is greater than 0°C for classification. If it is greater than 0°C, the energy-saving control mode can be used, thereby further avoiding condensation in the wind tunnel while achieving the goal of energy-saving operation of the entire wind tunnel.

[0032] 1. In humidity control mode, if the fresh air dew point temperature is greater than the wind tunnel set dew point temperature, the dehumidifier dehumidification dew point temperature in the dehumidification section is controlled to be equal to the wind tunnel set dew point temperature minus 10°C. Considering that the dehumidifier is prone to damage when it is in a high humidity state in the dehumidification section, from the perspective of protecting the dehumidifier while taking into account the energy-saving operation of the system, the dehumidifier is kept running, but the dehumidification dew point temperature of the dehumidifier is controlled to be only 10°C lower than the wind tunnel set dew point temperature. While ensuring the humidity control effect, it also greatly saves the amount of steam required for dehumidification by the dehumidifier, thus achieving the purpose of energy-saving operation of the fresh air humidity control section. The setting of 10°C lower provides a margin for humidity control, which not only ensures that the dehumidification section effectively controls the humidity of the fresh air, but also prevents condensation when the fresh air with excessive humidity enters the wind tunnel, which may affect the smooth progress of the test.

[0033] 2. Under high-temperature test conditions, the first heat exchanger in the dehumidification section, the second heat exchanger in the high-flow section, and the steam heater are all set to control the fresh air temperature to the set temperature plus 10°C. Compared with the existing fresh air humidity control system, setting the first heat exchanger and the second heat exchanger to 10°C can greatly reduce the amount of steam consumed in the dehumidification section and the high-flow section.

[0034] Preferably, in S4, if the fresh air dew point temperature is less than or equal to the wind tunnel set dew point temperature, the dehumidifier dehumidification dew point temperature is controlled to be equal to the fresh air dew point temperature minus 10°C.

[0035] The beneficial effect of this solution is: if the fresh air dew point temperature is ≤ the wind tunnel set dew point temperature, the dehumidifier set dew point is equal to the fresh air dew point temperature minus 10°C; while also ensuring energy-saving operation, the dehumidification effect of the dehumidification section is ensured to avoid condensation after the fresh air enters the wind tunnel with too high humidity, which affects the smooth progress of the test.

[0036] Preferably, in S3, if the wind tunnel set dew point temperature is less than or equal to 0°C, the dehumidification mode is entered, and the dehumidification dew point temperature of the dehumidifier is first controlled to be -45°C; then the fresh air temperature in the dehumidification section is controlled to be 10°C, and the fresh air temperature in the large flow section is controlled to be equal to the set temperature.

[0037] The beneficial effects of this solution are as follows: In dehumidification mode, to improve dehumidification efficiency, the dehumidifier's dehumidification dew point temperature is set to a minimum set temperature of -45°C, ensuring faster dehumidification. Furthermore, since the dehumidifier is required to ultimately achieve dehumidification at an extremely low dew point temperature of -45°C in dehumidification mode, the fresh air is cooled to 10°C in the dehumidification section to ensure effective dehumidification. The fresh air temperature in the high-flow section is controlled to the set temperature for wind tunnel testing. Compared to existing fresh air humidity control systems that control the fresh air temperature at 10°C, this reduces the operating efficiency of the high-flow section, thereby achieving energy savings.

[0038] Preferably, in S2, if the set temperature is less than or equal to 0°C, it indicates that the wind tunnel is in a low-temperature test condition, and the fresh air is sent into the wind tunnel after being cooled and humidified by the small flow section.

[0039] The beneficial effect of this scheme is: if the temperature is less than or equal to 0℃, it indicates that the wind tunnel is in a low-temperature test condition. At this time, the fresh air in the fresh air humidity control system is cooled and humidified in a small flow section and then sent into the wind tunnel. Its control method is the same as the existing control method to ensure the accuracy of the wind tunnel test. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow chart of a wind tunnel energy-saving operation method according to an embodiment of the present invention;

[0041] Figure 2 Schematic diagram of the structure of a wind tunnel in an embodiment of the present invention;

[0042] Figure 3 This is a flow chart of the energy-saving control mode of the new air and humidity control system in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The following is further described in detail through specific implementation methods:

[0044] The figure marks in the drawings of the specification include: fresh air humidity control system 1, heating system 2, cryogenic system 3, first cryogenic unit 31, second cryogenic unit 32, tail exhaust system 4, first corner 101, second corner 102, third corner 103, fourth corner 104, nozzle 105, stationary chamber 106, insulation bin plate 107, collection port 108, crawler drum pit cover 109, drum 110, drum pit 111, main fan 112, main heat exchanger 113, sunlight simulation system 114, main circulation pump 115, cold side large flow three-way regulating valve 116, cold side small flow three-way regulating valve 117, hot side large flow three-way regulating valve 118, hot side small flow three-way regulating valve 119, first auxiliary circulation inlet 120, first auxiliary circulation outlet 121, second auxiliary circulation inlet 122, second auxiliary circulation outlet 123.

[0045] Example

[0046] The embodiment is basically as shown in the attached Figure 1-3 As shown, Figure 1 The energy-saving operation method for an automotive environmental wind tunnel shown is applied to the automatic control system of an automotive environmental wind tunnel. While ensuring that the automotive environmental wind tunnel meets the various environmental simulation requirements required for automotive testing, the subsystems in the automatic control system are reasonably started and stopped to achieve the purpose of reducing the operating costs of the wind tunnel and realizing energy-saving operation of the wind tunnel.

[0047] The energy-saving operation method includes the following steps: first, starting the automobile environmental wind tunnel operation command, inputting the set temperature and set humidity into the wind tunnel automatic control system according to the test requirements, and the wind tunnel automatic control system enters energy-saving operation:

[0048] S1, determine whether the wind tunnel is in preparation mode.

[0049] After the automotive environmental wind tunnel is started, it includes two modes: preparation mode and test mode. In preparation mode, the wind tunnel only adjusts the temperature and humidity, that is, through the operation of subsystems such as the new air humidity control system, heating system, deep cooling system and tail exhaust system, the temperature and humidity inside the wind tunnel are adjusted to the set temperature and set humidity required for the test, in preparation for subsequent vehicle testing; in preparation mode, the maximum wind speed inside the wind tunnel is 30km / h, and staff can enter and exit the wind tunnel. Test mode is the state where the wind tunnel officially begins to conduct automotive environmental simulation tests. The temperature and humidity inside the wind tunnel must be stabilized at the set values ​​required for the test through the operation of each subsystem, and in test mode, the wind speed inside the wind tunnel can reach up to 200km / h, and personnel cannot enter and exit the wind tunnel. After the preparation mode ends, the wind tunnel enters test mode.

[0050] S2, when it is determined that the wind tunnel is not in the preparation mode, it indicates that the wind tunnel is in the test mode.

[0051] In test mode, the test set temperature is determined to be greater than a second threshold, which represents the wind tunnel test set temperature. If greater than a second threshold, the wind tunnel test set temperature is relatively high. The cooling capacity provided by some cryogenic units in the cryogenic system is sufficient to maintain the set temperature during the test. Therefore, some cryogenic units are controlled to operate, and the fresh air humidity control system, heating system, and exhaust system are activated. This control ensures that the wind tunnel automatic control system can promptly increase the temperature through the heating system, decrease the temperature through the cryogenic system, or utilize the fresh air humidity control system and exhaust system for dehumidification and humidification based on detected deviations during the test, ensuring that the temperature and humidity inside the wind tunnel are maintained at the set test temperature and humidity, thereby ensuring the accuracy of the vehicle test results. If less than or equal to a second threshold, the wind tunnel test set temperature is relatively low. To maintain the set temperature, a large cooling capacity is required. Therefore, the fresh air humidity control system, heating system, exhaust system, and the entire cryogenic system need to be activated.

[0052] In preparation mode, first determine the difference between the set temperature and the actual temperature of the wind tunnel.

[0053] S3: If the difference between the set temperature and the actual temperature exceeds a first threshold value, which is the difference between the wind tunnel test set temperature and the current actual temperature inside the wind tunnel, it indicates that the difference between the set temperature and the actual temperature of the wind tunnel is large, that is, the wind tunnel needs to run for a period of time before the actual temperature inside the wind tunnel is adjusted to the set temperature required for the test. Then, it is determined whether the set temperature is greater than the actual temperature.

[0054] When the set temperature is greater than the actual temperature, and the difference between the two exceeds the first threshold, indicating that the set temperature is significantly higher than the actual temperature and the wind tunnel needs to be heated up, the cryogenic system is not required under these operating conditions. Therefore, the cryogenic system, the fresh air humidity control system, and the exhaust system are shut down, and the heating system is activated. This reduces system operation and achieves energy savings. The reason for shutting down the fresh air humidity control system and the exhaust system during this process is that the temperature rise is a transition from low temperature to high temperature, and humidity control is not necessary. There are two reasons why humidity control is not needed. First, in the actual process of controlling the temperature and humidity of the wind tunnel, the speed of controlling humidity is faster, while the speed of completing heating is slower, especially when the wind tunnel is in preparation mode for switching from low-temperature test to high-temperature test immediately. It usually takes 3 to 4 hours for the wind tunnel to heat up, but once the temperature is reached, humidity control can be completed in 20 minutes. If the new air humidity control system and the tail exhaust system are turned on for humidity control at the beginning, a large amount of electricity and steam (i.e., gas consumption) will be consumed, thereby increasing operating costs. Second, there is a sunlight simulation system in the wind tunnel, which simulates sunlight through lighting. In the process of heating up the wind tunnel, the glass heating rate of the sunlight simulation system will be lower than the heating rate of the air in the wind tunnel, i.e., the glass temperature is lower than the ambient temperature inside the wind tunnel. At this time, if humidity control is performed, steam will enter the wind tunnel, resulting in condensation water adhering to the glass surface. As the sunlight simulation system starts, the lights emit light and a large amount of heat, and the glass is very likely to burst. That is, stopping humidity control can also protect the wind tunnel equipment.

[0055] When the set temperature is lower than the actual temperature, and the difference between the set temperature and the actual temperature exceeds the first threshold, indicating that the set temperature is much lower than the actual temperature, the wind tunnel needs to be cooled. In this case, the heating system does not need to be activated, but the fresh air humidity control system and tail exhaust system must be activated for humidity control, and the entire cryogenic system must be activated for rapid cooling. At this point, turning off the heating system saves energy; the reason for turning on the fresh air humidity control system and tail exhaust system is that cooling is a process of going from high temperature to low temperature, and the wind tunnel needs to be dehumidified to prevent condensation from occurring when the air temperature inside the wind tunnel drops below the dew point during the cooling process. This condensation can adhere to the surfaces of various equipment inside the wind tunnel, causing equipment shutdown or damage.

[0056] S4, determining that the current set temperature inside the wind tunnel is equal to the actual temperature. At this time, the wind tunnel does not need to be heated up or cooled down; the next control step can be carried out.

[0057] S5 determines whether the set temperature is greater than a second threshold. If so, some cryogenic units in the cryogenic system are controlled to operate, and the fresh air humidity control system, heating system, and exhaust system are activated. If less than or equal to the set temperature, the fresh air humidity control system, heating system, exhaust system, and the entire cryogenic system are activated. This step operates different subsystems by determining the relationship between the set temperature and the second threshold. The control principle in this step is the same as the control principle in the test mode in S2 and will not be repeated here.

[0058] And as Figure 1 As shown, in S3, if the difference between the set temperature and the actual temperature is within the first threshold range, it indicates that the actual temperature inside the wind tunnel is not much different from the set temperature at this time, and it will not take long for the actual temperature inside the wind tunnel to reach the set temperature. Therefore, there is no need to start and stop different subsystems in the standby mode. Operation can be directly carried out by determining whether the set temperature is greater than the second threshold. Similarly, if the set temperature is greater than the second threshold, some cryogenic units in the cryogenic system are controlled to operate, and the fresh air humidity control system, heating system, and exhaust system are started; if it is less than or equal to the second threshold, the fresh air humidity control system, heating system, exhaust system, and the entire cryogenic system are started.

[0059] Next, we will use the specific automotive environmental wind tunnel automatic control system as an example to explain the energy-saving operation method in detail:

[0060] like Figure 2 As shown, the automatic control system of the automobile environmental wind tunnel includes subsystems: a fresh air humidity control system 1, a heating system 2, a deep cooling system 3 and a tail exhaust system 4; the wind tunnel is provided with a first corner 101, a second corner 102, a third corner 103, a fourth corner 104, a nozzle 105, a stationary chamber 106, an insulation compartment plate 107, a collection port 108, a crawler-type drum pit cover 109, a drum 110, a drum pit 111, a main fan 112, a main heat exchanger 113 and a sunlight simulation system 114 to realize various environmental simulations in the wind tunnel.

[0061] The fresh air humidity control system 1 is connected at the second corner 102 and is used to control the humidity of the outside air before sending it into the wind tunnel. The tail exhaust system 4 is located at the bottom of the stationary chamber 106 to discharge the exhaust gas and waste gas in the wind tunnel. The fresh air humidity control system 1 and the tail exhaust system 4 cooperate to control the humidity inside the wind tunnel. The heating system 2 and the cryogenic system 3 are both connected at the third corner 103 to control the temperature inside the wind tunnel. In this embodiment, the cryogenic system 3 is equipped with two cryogenic units, namely a first cryogenic unit 31 and a second cryogenic unit 32. The third corner 103 is equipped with a main circulation pump 115, a cold side high flow three-way regulating valve 116, a cold side low flow three-way regulating valve 117, a hot side high flow three-way regulating valve 118, a hot side low flow three-way regulating valve 119, a first auxiliary circulation inlet 120, a first auxiliary circulation outlet 121, a second auxiliary circulation inlet 122, and a second auxiliary circulation outlet 123. When the wind tunnel needs to be cooled, the refrigerant in the first auxiliary circulation inlet 120 is regulated by the cold-side high-flow three-way regulating valve 116 and the cold-side low-flow three-way regulating valve 117. A portion of the refrigerant enters the main heat exchanger 113 through the main circulation pump 115, absorbs heat from the air, and then returns to the first auxiliary circulation outlet 121. The refrigerant, after absorbing heat, is cooled by the first and second cryogenic units 31 and 32, completing the refrigeration cycle. The first and second cryogenic units 31 and 32 act as cold sources. When the wind tunnel needs to be heated, the hot liquid in the second auxiliary circulation inlet 122 is regulated by the hot-side high-flow three-way regulating valve 118 and the hot-side low-flow three-way regulating valve 119. A portion of the hot liquid enters the main heat exchanger 113 through the main circulation pump 115 to release heat to the air, and then returns to the second auxiliary circulation outlet 123, completing the heating cycle. The heating system 2 is provided with a steam source, which acts as a heat source.

[0062] In this embodiment, the first threshold range is -20°C to 20°C. This means that in standby mode, the difference between the set temperature and the actual temperature is determined to be greater than 20°C. If the difference is less than 20°C, the time required to adjust the actual temperature to the set temperature is relatively short, and the energy-saving effect of controlling the start and stop of heating system 2 and cryogenic system 3 during this period is not significant. The second threshold is 5°C. Based on actual wind tunnel operation, when the set temperature in the wind tunnel is greater than 5°C, one cryogenic unit in cryogenic system 3 is activated, and the cooling capacity it provides is sufficient to stabilize the set temperature during testing. When the set temperature is below 5°C, both cryogenic units in cryogenic system 3 need to be activated to achieve the desired set temperature.

[0063] The specific implementation process is as follows Figure 1 As shown, start the automobile environment wind tunnel operation command, enter the set temperature and set humidity required for the test, and the wind tunnel automatic control system enters energy-saving operation.

[0064] If the wind tunnel is determined to be in non-standby mode, it indicates that the wind tunnel is in test mode. The system then checks whether the set temperature is greater than 5°C. If so, the wind tunnel is at room or high temperature. At this point, one cryogenic unit in cryogenic system 3 is activated, and the cooling capacity provided by its operation can meet the required stabilization of the wind tunnel set temperature. If two cryogenic units were activated, their power would need to be reduced through frequency conversion, sliding valves, and hot gas bypass. However, the required cooling capacity of the wind tunnel is small, and the unit efficiency is low. Furthermore, each cryogenic unit is equipped with a cooling water pump, chilled water pump, oil cooling pump, and frequency converter, all of which consume significant energy, making it far less energy-efficient than a single cryogenic unit. Simultaneously, the fresh air humidity control system 1, heating system 2, and exhaust system 4 are controlled to ensure that the test environment is consistent with the set temperature. If the test set temperature is less than 5°C, the wind tunnel is at low temperature. To accurately control the wind tunnel test temperature, both cryogenic units must be activated for cooling, which means all subsystems must be activated.

[0065] When the wind tunnel is in preparation mode and the set temperature is greater than the actual temperature by +20°C, it means that the set temperature is much higher than the actual temperature and the wind tunnel needs to be heated up. Then, the cryogenic system 3 is shut down, the pumps and devices attached to the two cryogenic units are stopped, and at the same time, the cold side high-flow three-way regulating valve 116 and the cold side low-flow three-way regulating valve 117 are closed, the fresh air humidity control system 1 and the tail exhaust system 4 are shut down, and only the heating system 2 is turned on to heat the wind tunnel. As the temperature inside the wind tunnel rises, the actual temperature reaches the set temperature, and the wind tunnel is about to enter the test mode, so as to judge again whether the set temperature is greater than 5°C. If it is greater than 5°C, it means that the wind tunnel is at room temperature or high temperature. At this time, one of the cryogenic units in the cryogenic system 3 is controlled to start working to achieve energy-saving operation. In this state, since humidity control is not required for temperature increase, the fresh air humidity control system 1 and the tail exhaust system 4 will not be turned on until the actual temperature reaches the set temperature. This can avoid the situation in which condensation water adheres to the internal equipment of the wind tunnel during the temperature increase process, such as the glass temperature in the sunlight simulation system 114 being lower than the wind tunnel air temperature, causing the glass to burst due to heat after the lighting is started. In addition, the operation of the fresh air humidity control system 1 and the tail exhaust system 4 can greatly reduce the operating cost of the temperature increase stage and achieve the purpose of energy-saving operation.

[0066] When the wind tunnel is in preparation mode and the set temperature is less than the actual temperature by -20°C, it means that the set temperature is much lower than the actual temperature and the wind tunnel needs to be cooled. Therefore, the heating system 2 is controlled to be shut down, and the hot side high-flow three-way regulating valve 118 and the hot side low-flow three-way regulating valve 119 are closed at the same time, and the fresh air humidity control system 1 and the tail exhaust system 4 are turned on, as well as the two cryogenic units in the entire cryogenic system 3. As the temperature in the wind tunnel decreases, the actual temperature reaches the test set temperature, and the wind tunnel is about to enter the test mode, so as to judge again whether the set temperature is greater than 5°C. If it is greater than 5°C, it means that the wind tunnel is at room temperature or high temperature. At this time, one of the cryogenic units in the cryogenic system 3 is controlled to start working to achieve energy-saving operation.

[0067] When the wind tunnel is in preparation mode and the difference between the set temperature and the actual temperature is less than 20°C, it means that the difference between the set temperature and the actual temperature is small, and the temperature control in the wind tunnel will soon end. The wind tunnel will enter test mode. At this time, the system can directly determine whether the set temperature is greater than 5°C.

[0068] At the same time, in order to further improve the energy-saving operation effect of the wind tunnel, the present invention provides an energy-saving control mode in the fresh air humidity control system. The wind tunnel automatic control system controls the fresh air humidity control system to operate in an energy-saving manner according to different wind tunnel set temperatures.

[0069] like Figure 3 The energy-saving control mode of the fresh air humidity control system shown is applied to the existing fresh air humidity control system. And the fresh air humidity control system in this example has been disclosed in the patent "Environmental Wind Tunnel Humidity Rapid Adjustment System and Adjustment Method" (Publication No.: CN108344554B). The fresh air humidity control system includes a dehumidification section, a large flow section and a small flow section. The dehumidification section cools and dehumidifies the fresh air, including a dehumidifier and a first heat exchanger; the large flow section heats and humidifies or dehumidifies or heats the fresh air, including a second heat exchanger and a steam heater; the small flow section cools the fresh air. The outside fresh air passes through the first heat exchanger of the dehumidification section to reduce the air temperature to 10°C, and then enters the large flow section or the small flow section after dehumidification by the dehumidifier, and is finally sent into the wind tunnel by the small flow section or the large flow section.

[0070] The normal operation of the fresh air humidity control system is not energy-efficient. For example, if the outside fresh air temperature is 10℃~40℃, and the test requires the set temperature of the wind tunnel to be higher than the outside fresh air temperature, in the normal mode, the dehumidification section will still first reduce the air temperature to 10℃ for pre-dehumidification, but the cooling capacity here needs to exceed 200kw, and a lot of energy can be saved without pre-dehumidification; and although the air temperature will rise after passing through the dehumidifier, it is not necessary to cool the fresh air to 10℃ when passing through the large flow section. Considering the subsequent humidification, it only needs to be cooled to the wind tunnel set temperature or 10℃ higher than the set temperature.

[0071] like Figure 3As shown in FIG. 1 , when the wind tunnel automatic control system controls the fresh air humidity control system to start, the energy-saving control mode begins to operate (the steps of the energy-saving mode are represented by S1-1 and S2-1 to distinguish them from the above S1 and S2):

[0072] S1-1, first determine whether the wind tunnel set temperature is greater than 0℃. If it is less than or equal to 0℃, it indicates that the wind tunnel is in low-temperature test conditions. At this time, the fresh air in the fresh air humidity control system is sent into the wind tunnel after cooling and humidity control in the small flow section. Its control method is the same as the existing control method to ensure the accuracy of the wind tunnel test; if the set temperature is greater than 0℃, it indicates that the fresh air is sent into the wind tunnel from the large flow section and enters the energy-saving control mode.

[0073] S2-1, determining a wind tunnel set dew point temperature corresponding to the wind tunnel set humidity and set temperature.

[0074] S3-1: If the wind tunnel dew point temperature is greater than 0°C, the system enters the humidity control mode; if the wind tunnel dew point temperature is less than or equal to 0°C, the system enters the dehumidification mode.

[0075] In dehumidification mode, the dehumidifier in the dehumidification section dehumidifies the fresh air at varying levels of intensity based on the dew point temperature input by the system. The lower the dehumidifier's dehumidification dew point, the greater the dehumidification intensity. Therefore, to maximize dehumidification efficiency in dehumidification mode, the dehumidifier's dehumidification dew point is set to a minimum set point of -45°C to ensure faster dehumidification. The reason for controlling the fresh air temperature in the dehumidification section to 10°C and the fresh air temperature in the high-flow section to the wind tunnel setpoint is that, in dehumidification mode, the dehumidifier must ultimately achieve dehumidification at an extremely low dew point of -45°C. Therefore, in the dehumidification section, the first heat exchanger is used to cool the fresh air to 10°C to ensure effective dehumidification. In the high-flow section, the second heat exchanger and steam heater are used to control the fresh air temperature to the wind tunnel test setpoint. Compared to existing fresh air humidity control systems that maintain a constant fresh air temperature of 10°C, this reduces the efficiency of the high-flow section, thereby saving energy.

[0076] In humidity control mode, first determine whether the fresh air dew point temperature is greater than the wind tunnel set dew point temperature.

[0077] In step S4-1, if the fresh air dew point temperature is greater than the wind tunnel set dew point temperature, the dehumidifier dehumidification dew point temperature in the dehumidification section is controlled to be equal to the wind tunnel set dew point temperature minus 10°C. This setting is due to the fact that, in humidity control mode, while it is desirable to keep the dehumidifier inactive for energy conservation, the high humidity in the dehumidification section over time can easily damage the dehumidifier. Therefore, to protect the dehumidifier while balancing system energy conservation, the dehumidifier is kept in operation, but the dehumidification dew point temperature is controlled to be only 10°C lower than the wind tunnel set dew point temperature. This ensures effective humidity control while significantly reducing the amount of steam consumed by the dehumidifier, thus achieving energy conservation in the fresh air humidity control section. The 10°C lower setting provides a margin for humidity control, ensuring effective fresh air humidity control in the dehumidification section while preventing condensation when the fresh air enters the wind tunnel due to excessive humidity, which could affect the smooth progress of the test.

[0078] If the fresh air dew point temperature is less than or equal to the wind tunnel set dew point temperature, set the dehumidifier dew point to equal the fresh air dew point temperature minus 10°C. This also ensures energy-saving operation while ensuring the dehumidification effect of the dehumidification section, preventing condensation after the fresh air enters the wind tunnel due to excessive humidity, which could affect the smooth progress of the test.

[0079] S5-1, control the fresh air temperature in the dehumidification section and the large flow section to be equal to the set temperature plus 10℃.

[0080] The first heat exchanger in the dehumidification section, the second heat exchanger in the high-flow section, and the steam heater are all set to control the fresh air at the set temperature plus 10°C. Compared to existing fresh air humidity control systems that set the first and second heat exchangers to 10°C, this can significantly reduce the amount of steam consumed by the dehumidification and high-flow sections. In actual use, because the set temperatures of the first and second heat exchangers are typically higher, the first heat exchanger is in the closed cooling state most of the time, and the cooling capacity of the second heat exchanger is very small. The cooling of the second heat exchanger is mainly due to the slight increase in the temperature of the fresh air after dehumidification by the dehumidifier, necessitating cooling control. For example, when conducting automotive tests in a wind tunnel with a set temperature of 40°C and a set humidity of 50%, while the outside air temperature is 25°C and the humidity is 40%, the first and second heat exchangers set the fresh air temperature to 35°C, 25°C higher than the outside air temperature by 10°C. Therefore, no cooling is required during the dehumidification phase, while only a small amount is required during high-flow phases. Compared to existing systems that cool the air to 10°C, this solution can save 300-400kW of cooling capacity. Furthermore, because the second heat exchanger has already adjusted the outside air temperature to the wind tunnel set temperature plus 10°C, the steam heater essentially does not need to operate, further saving significant steam. The 10°C higher temperature setting is based on the same principle as humidity control: it prevents condensation in the wind tunnel and acts as an anti-condensation agent.

[0081] In summary, this energy-saving operation method for an automotive environmental wind tunnel can significantly reduce operating costs when the wind tunnel is operating at room temperature and high temperature simulation tests, while ensuring that the wind tunnel test can accurately control temperature and humidity. It is estimated that the energy-saving operation method can save the wind tunnel operating costs by more than 500,000 yuan per year.

[0082] The above is only an embodiment of the present invention, and the common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A method for energy-saving operation of an automobile environmental wind tunnel, applied to an automobile environmental wind tunnel automatic control system, characterized by: The steps include: S1, determine whether the wind tunnel is in preparation mode; S2, when the wind tunnel is in a preparation mode, determining a difference between a set temperature of the wind tunnel and an actual temperature of the wind tunnel; S3, if the difference between the set temperature and the actual temperature exceeds the first threshold range, then determine whether the set temperature is greater than the actual temperature; If it is greater than, shut down the fresh air humidity control system, cryogenic system and tail exhaust system, and start the heating system; if it is less than, shut down the heating system, and start the fresh air humidity control system, cryogenic system and tail exhaust system; S4, determining whether the current set temperature inside the wind tunnel is equal to the actual temperature; S5, determining whether the set temperature is greater than a second threshold value. If so, controlling some cryogenic units in the cryogenic system to operate, and starting the fresh air humidity control system, the heating system, and the exhaust system; If it is less than or equal to, start the new air humidity control system, heating system, tail exhaust system and the entire deep cooling system.

2. The energy-saving operation method of an automobile environmental wind tunnel according to claim 1, characterized in that: In S3, if the difference between the set temperature and the actual temperature is within the first threshold range, it is determined whether the set temperature is greater than the second threshold. If so, some cryogenic units in the cryogenic system are controlled to operate, and the fresh air humidity control system, heating system, and tail exhaust system are started; If it is less than or equal to, start the new air humidity control system, heating system, tail exhaust system and the entire deep cooling system.

3. The energy-saving operation method of an automobile environmental wind tunnel according to claim 2, characterized in that: In S2, the wind tunnel is not in the preparation mode, indicating that the wind tunnel is in the test mode; it is determined whether the set temperature is greater than the second threshold. If so, some cryogenic units in the cryogenic system are controlled to operate, and the fresh air humidity control system, heating system, and tail exhaust system are started; If it is less than or equal to, start the new air humidity control system, heating system, tail exhaust system and the entire deep cooling system.

4. The energy-saving operation method of an automobile environmental wind tunnel according to claim 3, characterized in that: The first threshold range is between -20°C and 20°C.

5. The energy-saving operation method of an automobile environmental wind tunnel according to claim 3, characterized in that: The second threshold is 5°C.

6. The energy-saving operation method of an automobile environmental wind tunnel according to any one of claims 4-5, characterized in that: The new air and humidity control system is equipped with an energy-saving control mode, which includes the following steps: S1-1, determine whether the set temperature is greater than 0℃; S2-1, if the set temperature is greater than 0°C, determine the wind tunnel set dew point temperature at the wind tunnel set humidity and set temperature; S3-1, if the wind tunnel set dew point temperature is greater than 0℃, enter the humidity control mode and determine whether the fresh air dew point temperature is greater than the wind tunnel set dew point temperature; S4-1, if the fresh air dew point temperature is greater than the wind tunnel set dew point temperature, control the dehumidifier dehumidification dew point temperature to be equal to the wind tunnel set dew point temperature minus 10℃; S5-1, control the fresh air temperature in the dehumidification section and the large flow section to be equal to the set temperature plus 10℃.

7. The energy-saving operation method of an automobile environmental wind tunnel according to claim 6, characterized in that: In S4-1, if the fresh air dew point temperature is less than or equal to the wind tunnel set dew point temperature, the dehumidifier dehumidification dew point temperature is controlled to be equal to the fresh air dew point temperature minus 10°C.

8. The energy-saving operation method of an automobile environmental wind tunnel according to claim 6, characterized in that: In S3-1, if the wind tunnel set dew point temperature is less than or equal to 0℃, it enters the dehumidification mode, first controlling the dehumidification dew point temperature of the dehumidifier to -45℃; then controlling the fresh air temperature in the dehumidification section to 10℃, and controlling the fresh air temperature in the large flow section to be equal to the set temperature.

9. The method for energy-saving operation of an automobile environmental wind tunnel according to claim 6, characterized in that: In S2-1, if the set temperature is less than or equal to 0℃, it indicates that the wind tunnel is in low-temperature test conditions, and the fresh air is sent into the wind tunnel after being cooled and humidified by the small flow section.

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