A device and method for controlling extreme heat and humidity parameters of a climate wind tunnel

Abstract

The present invention discloses a device and method for controlling extreme heat and humidity parameters of a climate wind tunnel. The device includes a fan, a first cooler, a second cooler, a first heater, a second heater, a rotary dehumidifier and a steam humidifier; the second cooler is connected in series with the rotary dehumidifier to form a dehumidification circuit, the first heater is connected in series with the steam humidifier to form a heating circuit, and the dehumidification circuit is connected in parallel with the heating circuit, and then connected in series with the second heater, the fan and the first cooler in turn; the first cooler and the second cooler are connected to the water supply and return pipelines respectively. The control method includes a three-level regulation and fine-tuning method for the extreme heat and humidity parameters of the wind tunnel, which solves the problem that the temperature and humidity are difficult to accurately control under extremely high temperature and high humidity conditions in the existing climate wind tunnel, and ensures the control accuracy under extremely high temperature and high humidity conditions; and overcomes the defect of hysteresis in the heating and dehumidification processes during temperature and humidity adjustment, improves the response speed of temperature and humidity, and saves operating energy consumption and equipment investment costs.

Description

Technical Field

[0001] The invention relates to the technical field of multi-parameter environmental control, and in particular to a device and method for controlling extreme heat and humidity parameters of a climate wind tunnel. Background Art

[0002] Wind tunnel tests have been widely used in aerospace, construction, meteorology and other fields due to their high control accuracy, good repeatability and no influence from outdoor climate conditions. In recent years, wind tunnels of various sizes and application types have been established, providing experimental platforms for scientific research in different fields. The control parameters of wind tunnels have also gradually increased from single wind speed to multiple parameters such as wind speed, temperature, humidity, etc., and have developed into periodic multi-parameter coupling control.

[0003] However, the control of temperature and humidity in a wind tunnel is a dynamic process, and its high-precision control is relatively complex and difficult, especially under extremely high temperature and high humidity conditions. In addition, there is a lag in the heating and dehumidification of the air in the wind tunnel, which brings greater challenges to the precise control of temperature and humidity in the wind tunnel. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects and shortcomings of the prior art and to provide a device for controlling extreme heat and humidity parameters of a climatic wind tunnel, which can accurately control the temperature and humidity under extremely high temperature and high humidity conditions in a climatic wind tunnel, thereby improving the response speed and operating stability.

[0005] Another object of the present invention is to provide a method for controlling extreme heat and humidity parameters of a climate wind tunnel, which can achieve three-level regulation of temperature and humidity in a climate wind tunnel and improve control accuracy.

[0006] The objective of the present invention can be achieved through the following technical scheme: a device for controlling extreme heat and humidity parameters of a climate wind tunnel, comprising a fan, a first cooler, a second cooler, a first heater, a second heater, a rotary dehumidifier and a steam humidifier; the second cooler is connected in series with the rotary dehumidifier to form a dehumidification circuit, the first heater is connected in series with the steam humidifier to form a heating circuit, after the dehumidification circuit is connected in parallel with the heating circuit, it is connected in series with the second heater, the fan and the first cooler in sequence; the first cooler and the second cooler are respectively connected to the supply and return water pipelines.

[0007] As a preferred technical solution, the fan is a variable frequency axial flow fan. With this structure, the fan can generate the periodic velocity field required for the specimen test and make the temperature and humidity of the air in the wind tunnel evenly distributed.

[0008] As a preferred technical solution, the first cooler is a primary air conditioning dehumidification cooler, and the second cooler is a dew point dehumidification cooler. With this structure, the first cooler is mainly used to cool the air in the climate wind tunnel, and the second cooler is mainly used to perform secondary dehumidification on the air that has been initially cooled and dehumidified by the first cooler.

[0009] As a preferred technical solution, the second heater is arranged before the wind tunnel test section. With this structure, the second heater can speed up the temperature rise of the air in the test section to meet the test requirements.

[0010] As a preferred technical solution, the supply and return water pipelines are connected in sequence to a chilled water system and a cooling water system. The chilled water system includes a chiller, a chilled water pump and a cold water tank, and the three are connected in sequence through a chilled water pipe to form a loop; the cooling water system includes a cooling tower, a cooling water filter, a cooling water pump and a chiller, and the four are connected in sequence through a cooling water pipe to form a loop.

[0011] As a preferred technical solution, the water supply and return pipeline includes a water supply pipeline and a water return pipeline, and a dry-condition water pump is arranged between the water supply pipeline and the water return pipeline. After adopting this structure, the dry-condition water pump adjusts the water supply temperature of the surface cooler by mixing high and low temperature cold water, thereby ensuring the cooling speed of the surface cooler and reducing the influence of condensation of the surface cooler on the fluctuation of humidity.

[0012] As a preferred technical solution, a butterfly valve is provided between the dry-condition water pump and the water supply pipeline, and a check valve is provided between the dry-condition water pump and the return pipeline.

[0013] Another object of the present invention can be achieved through the following technical scheme: a method for controlling extreme heat and humidity parameters of a climate wind tunnel, comprising the following steps: when cooling, cooling is performed by a first surface cooler; when heating, the first surface cooler performs coarse adjustment on the circulating air in the wind tunnel to raise the air temperature to below the required temperature; then the first heater and the second heater perform fine adjustment on the air temperature in turn to adjust the air temperature to near the required temperature and stabilize it; when humidifying, steam humidification is performed by a steam humidifier; when dehumidifying, the first surface cooler performs preliminary cooling and dehumidification on the circulating air in the wind tunnel; then the second surface cooler performs cooling and dehumidification on the air to form low-temperature, high-humidity wet air; finally, the rotary dehumidifier dehumidifies the air to make the air humidity meet the control requirements.

[0014] As a preferred technical solution, when the relative humidity of the air is greater than 95% and the air temperature in the wind tunnel is greater than 15°C, the dry working condition water pump is turned on to mix the low-temperature supply water in the water supply pipeline with the high-temperature return water in the return pipeline. The mixed water inlet temperature is controlled in sections according to the following formula:

[0015] When the air temperature is less than 40℃ and greater than 25℃, t c =t a -15;

[0016] When the air temperature is less than 25℃ and greater than 15℃, t c =t a -10;

[0017] where t c is the inlet water temperature, t a is the air temperature.

[0018] As a preferred technical solution, when the relative humidity of the air is less than 95%, or when the relative humidity of the air is greater than 95% and the air temperature in the wind tunnel is less than 15°C, the dry condition water pump is not turned on.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects: the control device of the present invention can realize three-level regulation and fine-tuning of heat and humidity parameters. It solves the problem that the temperature and humidity are difficult to accurately control under the extremely high temperature and high humidity conditions in the existing climate wind tunnel, and ensures the control accuracy under the extremely high temperature and high humidity conditions; and overcomes the defect of hysteresis in the heating and dehumidification process during temperature and humidity adjustment, improves the response speed of temperature and humidity, and saves operating energy consumption and equipment investment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of the extreme heat and humidity parameter control device of the climate wind tunnel in an embodiment of the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of the water supply and return pipeline in an embodiment of the present invention;

[0022] Figure 3 This is a diagram showing the change of air temperature and humidity at low wind speed without using the fine-tuning method in the embodiment of the present invention;

[0023] Figure 4 This is a diagram showing the change of air temperature and humidity at high wind speed without using the fine-tuning method in the embodiment of the present invention;

[0024] Figure 5 This is a diagram showing the change of air temperature and humidity at low wind speed using a micro-adjustment method in an embodiment of the present invention;

[0025] Figure 6 This is a diagram showing changes in air temperature and humidity at high wind speed using a micro-adjustment method in an embodiment of the present invention.

[0026] Among them: 1-1: fan, 1-2: first surface cooler, 1-3: second surface cooler, 1-4: first heater, 1-5: second heater, 1-6: rotary dehumidifier, 1-7: steam humidifier, 2-1: cooling tower, 2-2: cooling water filter, 2-3: cooling water pump, 2-4: chiller, 2-5: refrigerated water pump, 2-6: cold water tank, 2-7: supply and return water filter, 2-8: surface cooling water pump, 2-9: check valve, 2-10: butterfly valve, 2-11: dry condition water pump, 2-12: check valve, 2-13: return water pipeline, 2-14: supply water pipeline. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0028] like Figure 1 As shown, a device for controlling extreme heat and humidity parameters of a climate wind tunnel includes a fan, a first cooler, a second cooler, a first heater, a second heater, a rotary dehumidifier, and a steam humidifier. The second cooler is connected in series with the rotary dehumidifier to form a dehumidification circuit, the first heater is connected in series with the steam humidifier to form a heating circuit, and the dehumidification circuit and the heating circuit are connected in parallel and then connected in series with the second heater, the fan, and the first cooler.

[0029] The fan is a variable frequency axial flow fan, which is used to generate the periodic velocity field required for the specimen test and to make the temperature and humidity of the air in the wind tunnel evenly distributed. The first cooler is a primary air conditioning dehumidification cooler. The first cooler is mainly used for cooling the air in the climate wind tunnel. The second cooler is a dew point dehumidification cooler, which is used for secondary dehumidification of the air after the first cooler has been initially cooled and dehumidified. The second heater is set before the wind tunnel test section to speed up the heating of the air in the test section and meet the test requirements.

[0030] The first surface cooler and the second surface cooler are connected to the supply and return water pipelines respectively. Figure 2 As shown, the supply and return water pipelines are connected to the chilled water system and the cooling water system in sequence. The cooling water system includes a cooling tower, a cooling water filter, a cooling water pump and a chiller, and the four are connected in sequence through cooling water pipes to form a loop. The chiller is the core component of refrigeration, and its refrigeration process requires heat dissipation. The cooling water system first transports the heat dissipated by the chiller to the cooling tower through cooling water, and then discharges the heat into the atmosphere through the cooling tower. The chilled water system includes a chiller, a chilled water pump and a cold water tank, and the three are connected in sequence through chilled water pipes to form a loop. The chilled water system transports the cold energy generated by the chiller to the cold equipment through water as a medium. After adding the cold water tank, the chilled water is easy to distribute and transport, and the chiller can operate efficiently and stably.

[0031] The water supply and return pipelines include a water supply pipeline and a water return pipeline. The water supply pipeline transports chilled water to the first surface cooler and the second surface cooler, and the water return pipeline transports high-temperature return water back to the chilled water system and the cooling water system. Figure 2 The pipe indicated by the dotted line is the return pipe, and the pipe indicated by the solid line is the water supply pipe. The return pipe and the cold water tank connecting pipe are provided with a check valve, a surface cold water pump and a supply and return water filter in sequence.

[0032] The key to regulating high humidity conditions is to strictly control the water inlet temperature of the first and second surface coolers. Therefore, a dry working condition water pump is set between the water supply pipeline and the return water pipeline. The dry working condition water pump can mix high-temperature return water and low-temperature supply water, so as to facilitate the adjustment of the water inlet temperature of the surface cooler. A butterfly valve is set between the dry working condition water pump and the water supply pipeline, and a check valve is set between the dry working condition water pump and the return water pipeline to avoid backflow.

[0033] The method for three-level control of extreme heat and humidity parameters in the climate wind tunnel is as follows:

[0034] Temperature control process:

[0035] When cooling, the first surface cooler is mainly used for cooling.

[0036] When heating up, the circulating air in the wind tunnel passes through the first cooler for the first stage of heating, and then passes through two sets of heaters to achieve the second and third stage of rapid heating. The first cooler, the first heater and the second heater are sequentially arranged in the wind tunnel, and the second heater is arranged before the wind tunnel test section. The overall temperature control process adopts a combination of coarse adjustment and fine adjustment. First, the first cooler makes a coarse adjustment to the air temperature to raise the air temperature below the required temperature, and then the first heater and the second heater make a fine adjustment, and the PID controller controls the output of the heating amount to adjust the air temperature to near the required temperature and stabilize it.

[0037] Humidity control process:

[0038] During humidification, steam is sprayed through a steam humidifier.

[0039] During dehumidification, the fan drives the circulating air to pass through the first cooler, the second cooler, and the rotary dehumidifier to achieve three-stage rapid dehumidification. Since the air with the same relative humidity has a lower moisture content as the air temperature decreases. First, the high-temperature and high-humidity air passes through the first cooler for preliminary cooling and dehumidification, but the dehumidification amount is small, and the air still maintains a high temperature and high humidity state. Then the high-temperature and high-humidity air passes through the second cooler, and the air temperature is greatly reduced. When it is reduced to below the dew point temperature, a large amount of water vapor in the air condenses and precipitates, thereby effectively reducing the moisture content of the air and becoming low-temperature and high-humidity wet air. Finally, the low-temperature and high-humidity wet air enters the rotary dehumidifier, and is further adsorbed and strongly dehumidified through the adsorption material therein, so that the air humidity reaches the low humidity control requirements.

[0040] The entire dehumidification system fully combines the advantages of cooling dehumidification and rotary dehumidification methods. It is not only easy to adjust and run smoothly, but also saves energy consumption and equipment investment costs.

[0041] The method for fine-tuning the extreme heat and humidity parameters of the climate wind tunnel is as follows:

[0042] Temperature and humidity control is dynamic, and high-precision control is relatively complex and difficult, especially under extremely high temperature and high humidity conditions. When the air temperature in the wind tunnel is set to 40°C and the humidity is set to 98%, Figure 3 , 4 It is shown that at both low and high wind speeds, the air humidity in the wind tunnel reaches 98% first, but the air temperature is always around 37°C and cannot reach 40°C. At the same time, the humidity fluctuates violently at low wind speeds. The reason is that the high air temperature leads to a high dew point temperature, which makes it difficult to achieve an extremely high humidity state, making it difficult to stabilize the temperature and humidity control parameters, and causing the humidifier and dehumidifier to start and stop frequently. The traditional way is generally to solve the above problems by increasing the equipment load of the humidifier or heater.

[0043] Based on the above analysis, it can be found that in order to stably control the extremely high temperature and high humidity conditions of 40°C and 98%, the entire temperature and humidity control system needs to increase the equipment load of the humidifier or the first heater and the second heater, and add an additional cold water tank or heater to the surface cooler water supply pipeline. However, the additional heater heats the cold water from the cold water tank, causing the cold and hot to collide, which will directly cause energy waste. In addition, blindly increasing the load of the equipment will increase the initial investment and operating energy consumption of the entire wind tunnel.

[0044] The key to regulating high humidity conditions is to strictly control the water inlet temperature of the first and second coolers. The present invention regulates the water inlet temperature by means of a dry-condition water pump disposed between the water supply and return pipes of the coolers in the wind tunnel. When the relative humidity of the air is lower than 95%, in order to ensure the cooling rate of the first and second coolers, the water inlet of the first and second coolers comes directly from the cold water tank. When the relative humidity is greater than 95%, the dry-condition water pump is started to mix the high-temperature return water of the first and second coolers with the low-temperature supply water of the cold water tank, wherein the mixed water inlet temperature is precisely controlled in sections according to the following formula:

[0045] When the air temperature is greater than 25℃, t c =t a -15; 25<t a ≤40;

[0046] When the air temperature is less than 25℃ and greater than 15℃, t c =t a -10; 15<ta ≤25;

[0047] Air temperature 10<t a When the temperature is ≤15℃, the dry working water pump will not be started;

[0048] where t c is the inlet water temperature, t a is the air temperature.

[0049] After using the temperature and humidity micro-adjustment method, the test results are shown in Figure 5 , 6 ,and Figure 3 , 4 The results show that after setting the micro-adjustment mode, the temperature and humidity can reach the control state point under the most unfavorable wind speed of 1m / s and the highest wind speed of 10m / s under the extreme high temperature and high humidity conditions, and the fluctuation frequency and amplitude are significantly lower than those under the condition that the adjustment mode is not set. Under the extreme high temperature and high humidity conditions of the wind tunnel with a set temperature of 40℃ and a relative humidity of 98%, the root mean square error of the temperature after the micro-adjustment method is used is reduced from 3.0℃ to 0.1℃ when the wind speed is 1m / s, and from 2.9℃ to 0.1℃ when the wind speed is 10m / ; the root mean square error of the relative humidity is reduced from 0.9% to 0.5% when the wind speed is 1m / s, and from 0.3% to 0.2% when the wind speed is 10m / s; the fluctuation frequency of the relative humidity is reduced from 12 times / h to 4 times / h.

[0050] The temperature and humidity micro-adjustment method not only effectively improves the control accuracy under extreme high temperature and high humidity conditions, but also is conducive to energy-saving operation and can reduce the number of equipment such as water tanks and heaters, thereby reducing the initial investment in equipment.

[0051] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for controlling extreme heat and humidity parameters in a climate wind tunnel, characterized in that: A climate wind tunnel extreme heat and humidity parameter control device is used, the control device includes a fan, a first cooler, a second cooler, a first heater, a second heater, a rotary dehumidifier and a steam humidifier; the second cooler is connected in series with the rotary dehumidifier to form a dehumidification circuit, the first heater is connected in series with the steam humidifier to form a heating circuit, the dehumidification circuit is connected in parallel with the heating circuit, and then connected in series with the second heater, the fan and the first cooler in sequence; the first cooler and the second cooler are connected to the supply and return water pipelines respectively; The water supply and return pipeline includes a water supply pipeline and a water return pipeline, and a dry-condition water pump is arranged between the water supply pipeline and the water return pipeline; The control method comprises the following steps: When cooling, cooling is performed through the first surface cooler; When the temperature is increased, the first surface cooler performs rough adjustment on the circulating air in the wind tunnel to raise the air temperature to below the required temperature; then the first heater and the second heater perform fine adjustment on the air temperature in sequence to adjust the air temperature to near the required temperature and stabilize it; When humidifying, steam is sprayed through a steam humidifier for humidification; During dehumidification, the first surface cooler performs preliminary cooling and dehumidification on the circulating air in the wind tunnel; then the second surface cooler performs cooling and dehumidification on the air to form low-temperature, high-humidity wet air; finally, the rotary dehumidifier dehumidifies the air to make the air humidity meet the control requirements; When the relative humidity of the air is greater than 95% and the air temperature in the wind tunnel is greater than 15°C, the dry condition water pump is turned on to mix the low-temperature supply water in the water supply pipeline with the high-temperature return water in the return pipeline. The mixed water inlet temperature is controlled in sections according to the following formula: When the air temperature is less than or equal to 40°C and greater than 25°C, ; When the air temperature is less than or equal to 25°C and greater than 15°C, ; in is the inlet water temperature, is the air temperature.

2. A method for controlling extreme heat and humidity parameters of a climate wind tunnel according to claim 1, characterized in that: The fan is a variable frequency axial flow fan.

3. A method for controlling extreme heat and humidity parameters of a climate wind tunnel according to claim 1, characterized in that: The first surface cooler is a primary air conditioning dehumidification surface cooler, and the second surface cooler is a dew point dehumidification dedicated surface cooler.

4. A method for controlling extreme heat and humidity parameters of a climatic wind tunnel according to claim 1, characterized in that: The second heater is arranged before the wind tunnel test section.

5. The method for controlling extreme heat and humidity parameters of a climatic wind tunnel according to claim 1, characterized in that: The supply and return water pipelines are connected in sequence to the chilled water system and the cooling water system. The chilled water system includes a chiller, a chilled water pump and a cold water tank, and the three are connected in sequence through a chilled water pipe to form a loop; the cooling water system includes a cooling tower, a cooling water filter, a cooling water pump and a chiller, and the four are connected in sequence through a cooling water pipe to form a loop.

6. A method for controlling extreme heat and humidity parameters of a climatic wind tunnel according to claim 1, characterized in that: A butterfly valve is arranged between the dry-condition water pump and the water supply pipeline, and a check valve is arranged between the dry-condition water pump and the return water pipeline.

7. A method for controlling extreme heat and humidity parameters of a climatic wind tunnel according to claim 1, characterized in that: When the relative humidity of the air is less than 95%, or when the relative humidity of the air is greater than 95% and the air temperature in the wind tunnel is less than or equal to 15°C, the dry condition water pump will not be turned on.

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