A wind tunnel heat exchange system

Abstract

The present invention provides a wind tunnel heat exchange system, including a heating system, a cooling system, a water supply pump and a wind tunnel heat exchanger. The hot liquid supply pipe and the hot liquid return pipe of the heating system are respectively provided with a first electric valve and a second electric valve. The cold liquid supply pipe and the cold liquid return pipe of the cooling system are respectively provided with a third electric valve and a fourth electric valve. The hot liquid supply pipe and the cold liquid supply pipe are intersected to form a liquid supply pipe and connected to the liquid inlet of the wind tunnel heat exchanger. The hot liquid return pipe and the cold liquid return pipe are intersected to form a liquid return pipe connected to the water outlet of the wind tunnel heat exchanger. The liquid supply pipe and the liquid return pipe are connected through an electric three-way valve. The water supply pump is arranged on the liquid return pipe. A water-water heat exchanger is arranged between the cold liquid supply pipe and the liquid return pipe. A normal pressure storage tank is arranged on the liquid return pipe. The beneficial effects of the present invention are: PID adjustment can be performed on it according to the temperature detected by the sensor, and the liquid supply temperature and accuracy of the heat exchanger in the test hall meet the target requirements.

Description

Technical Field

[0001] The invention relates to the field of wind tunnel heat exchange systems, and more particularly to a wind tunnel heat exchange system. Background Art

[0002] The connected transonic wind tunnel needs to be cooled or heated to maintain the total temperature of the test airflow stable. The external cooling water flows through the heat exchanger installed in the heat exchange section of the wind tunnel to exchange heat with the wind tunnel airflow. Traditionally, changing the cooling water flow rate through a variable frequency water pump has little effect on the total heat transfer coefficient and the change in the heat transfer temperature difference is also limited. As a result, the total temperature adjustment range of the wind tunnel test airflow is narrow and the control accuracy is poor. Summary of the invention

[0003] The present invention overcomes the deficiencies in the prior art and provides a wind tunnel heat exchange system.

[0004] The purpose of the present invention is achieved through the following technical solutions.

[0005] A wind tunnel heat exchange system comprises a heating system, a refrigeration system, a water supply pump and a wind tunnel heat exchanger, wherein the hot liquid supply pipe and the hot liquid return pipe of the heating system are respectively provided with a first electric valve and a second electric valve, and the cold liquid supply pipe and the cold liquid return pipe of the refrigeration system are respectively provided with a third electric valve and a fourth electric valve, the hot liquid supply pipe and the cold liquid supply pipe are intersected to form a liquid supply pipe and connected to the liquid inlet of the wind tunnel heat exchanger, the hot liquid return pipe and the cold liquid return pipe are intersected to form a liquid return pipe and connected to the water outlet of the wind tunnel heat exchanger, the liquid supply pipe and the liquid return pipe are connected through an electric three-way valve, the water supply pump is arranged on the liquid return pipe, a water-water heat exchanger is arranged between the cold liquid supply pipe and the liquid return pipe, and a normal pressure storage tank is arranged on the liquid return pipe.

[0006] Furthermore, the heating system includes a main heater, a water outlet of the main heater is connected to the hot liquid supply pipe, a water inlet of the main heater is connected to the hot liquid return pipe, and a pressure storage tank is provided on the road between the second electric valve and the main heater.

[0007] Furthermore, the refrigeration system includes a refrigeration unit, a chilled water pump and a system constant pressure device, and the refrigeration unit, the chilled water pump and the system constant pressure device are connected in sequence.

[0008] Furthermore, the chilled water pumps are provided in three groups.

[0009] Furthermore, there are two electric three-way valves, a first electric three-way valve is arranged between the atmospheric pressure storage tank and the water pump, and a second electric three-way valve is arranged between the water-water heat exchanger and the chilled water pump.

[0010] Furthermore, there are four groups of water supply pumps.

[0011] Furthermore, the system also includes a PID controller, which accurately controls the reflux volume of the first electric valve, the second electric valve, the third electric valve, the fourth electric valve, the first electric three-way valve and the second electric three-way valve.

[0012] Furthermore, a temperature sensor is provided at the air inlet and outlet of the wind tunnel heat exchanger, and the temperature sensor is connected to the PID controller.

[0013] The beneficial effects of the present invention are:

[0014] Set up a normal pressure storage tank to store the cooled liquid to ensure the amount of low-temperature water;

[0015] The supply liquid in the cooling or heating state is mixed with the return liquid of the wind tunnel heat exchanger in proportion through the electric three-way valve, so that the supply liquid temperature and accuracy of the heat exchanger meet the target requirements;

[0016] The system can reach a low temperature of -15°C. Temperature sensors are distributed at the inlet and outlet of the heat exchanger. PID adjustment is performed according to the temperature detected by the sensor. The heat exchanger supply temperature and accuracy in the test hall meet the target requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the principle diagram of the system of the present invention;

[0018] In the figure:

[0019] 1. Refrigeration system; 2. Heating system; 3. Water supply pump; 4. Wind tunnel heat exchanger;

[0020] 5. First electric valve; 6. Second electric valve; 7. Third electric valve; 8. Fourth electric valve;

[0021] 9. Hot liquid supply pipeline; 10. Hot liquid return pipeline; 11. Cold liquid supply pipeline; 12. Cold liquid return pipeline;

[0022] 13. Liquid supply pipeline; 14. Liquid return pipeline; 15. Main heater; 16. First electric three-way valve;

[0023] 17. Pressure storage tank; 18. Refrigeration unit; 19. Chilled water pump; 20. System constant pressure device;

[0024] 21. Water-water heat exchanger; 22. Normal pressure storage tank; 23. Temperature sensor; 24. Second electric three-way valve. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below through specific embodiments.

[0026] Example 1

[0027] like Figure 1 The wind tunnel heat exchange system shown includes a heating system 2, a refrigeration system 1, a water supply pump 3 and a wind tunnel heat exchanger 4. The hot liquid supply pipe 9 and the hot liquid return pipe 10 of the heating system 2 are respectively provided with a first electric valve 5 and a second electric valve 6. The cold liquid supply pipe 11 and the cold liquid return pipe 12 of the refrigeration system 1 are respectively provided with a third electric valve 7 and a fourth electric valve 8. The hot liquid supply pipe 9 and the cold liquid supply pipe 11 are joined to form a liquid supply pipe 13 and are connected to the liquid inlet of the wind tunnel heat exchanger 4. The hot liquid return pipe 10 and the cold liquid return pipe 12 are joined to form a liquid return pipe 14 and are connected to the water outlet of the wind tunnel heat exchanger 4. The liquid supply pipe 13 and the liquid return pipe 14 are connected through a first electric three-way valve 16. The water supply pump 3 is arranged on the liquid return pipe 12. A water-water heat exchanger 21 is arranged between the cold liquid supply pipe 11 and the liquid return pipe 14. A normal pressure storage tank 22 is arranged on the liquid return pipe 14.

[0028] Example 2

[0029] like Figure 1 The wind tunnel heat exchange system shown includes a heating system 2, a refrigeration system 1, a water supply pump 3 and a wind tunnel heat exchanger 4. The hot liquid supply pipe 9 and the hot liquid return pipe 10 of the heating system 2 are respectively provided with a first electric valve 5 and a second electric valve 6. The cold liquid supply pipe 11 and the cold liquid return pipe 12 of the refrigeration system 1 are respectively provided with a third electric valve 7 and a fourth electric valve 8. The hot liquid supply pipe 9 and the cold liquid supply pipe 11 are joined to form a liquid supply pipe 13 and are connected to the liquid inlet of the wind tunnel heat exchanger 4. The hot liquid return pipe 10 and the cold liquid return pipe 12 are joined to form a liquid return pipe 14 and are connected to the water outlet of the wind tunnel heat exchanger 4. The liquid supply pipe 13 and the liquid return pipe 14 are connected through a first electric three-way valve 16. The water supply pump 3 is arranged on the liquid return pipe 12. A water-water heat exchanger 21 is arranged between the cold liquid supply pipe 11 and the liquid return pipe 14. A normal pressure storage tank 22 is arranged on the liquid return pipe 14.

[0030] The heating system 2 includes a main heater 15, the water outlet of the main heater 15 is connected to the hot liquid supply pipe 9, the water inlet of the main heater 15 is connected to the hot liquid return pipe 10, and a pressure storage tank 17 is provided on the road between the second electric valve 6 and the main heater 15. The power of the main heater 15 is 0-1200kW;

[0031] The refrigeration system 1 includes a refrigeration unit 18, a chilled water pump 19 and a system constant pressure device 20, which are connected in sequence;

[0032] There are three groups of chilled water pumps 19. In daily use, two chilled water pumps 19 are in operation, and an additional chilled water pump 19 is used as a backup.

[0033] There are four groups of water supply pumps 3. In daily use, three groups of water supply pumps 3 are in operation, and an additional water supply pump 3 is reserved for backup.

[0034] There are two electric three-way valves. The first electric three-way valve 16 is arranged between the atmospheric pressure storage tank 22 and the water supply pump 3 , and the second electric three-way valve 24 is arranged between the water-water heat exchanger 21 and the chilled water pump 19 .

[0035] Example 3

[0036] like Figure 1 The wind tunnel heat exchange system shown includes a heating system 2, a refrigeration system 1, a water supply pump 3 and a wind tunnel heat exchanger 4. The hot liquid supply pipe 9 and the hot liquid return pipe 10 of the heating system 2 are respectively provided with a first electric valve 5 and a second electric valve 6. The cold liquid supply pipe 11 and the cold liquid return pipe 12 of the refrigeration system 1 are respectively provided with a third electric valve 7 and a fourth electric valve 8. The hot liquid supply pipe 9 and the cold liquid supply pipe 11 are joined to form a liquid supply pipe 13 and are connected to the liquid inlet of the wind tunnel heat exchanger 4. The hot liquid return pipe 10 and the cold liquid return pipe 12 are joined to form a liquid return pipe 14 and are connected to the water outlet of the wind tunnel heat exchanger 4. The liquid supply pipe 13 and the liquid return pipe 14 are connected through a first electric three-way valve 16. The water supply pump 3 is arranged on the liquid return pipe 12. A water-water heat exchanger 21 is arranged between the cold liquid supply pipe 11 and the liquid return pipe 14. A normal pressure storage tank 22 is arranged on the liquid return pipe 14.

[0037] The heating system 2 includes a main heater 15, the water outlet of the main heater 15 is connected to the hot liquid supply pipe 9, the water inlet of the main heater 15 is connected to the hot liquid return pipe 10, and a pressure storage tank 17 is provided on the road between the second electric valve 6 and the main heater 15. The power of the main heater 15 is 0-1200kW;

[0038] The refrigeration system 1 includes a refrigeration unit 18, a chilled water pump 19 and a system constant pressure device 20, which are connected in sequence;

[0039] There are three groups of chilled water pumps 19. In daily use, two chilled water pumps 19 are in operation, and an additional chilled water pump 19 is used as a backup.

[0040] There are four groups of water supply pumps 3. In daily use, three groups of water supply pumps 3 are in operation, and an additional water supply pump 3 is reserved for backup.

[0041] There are two electric three-way valves 16 . The first electric three-way valve 16 is arranged between the atmospheric pressure storage tank 22 and the water supply pump 3 , and the second electric three-way valve 24 is arranged between the water-water heat exchanger 21 and the chilled water pump 19 .

[0042] The system also includes a PID controller, which accurately controls the reflux volume of the first electric valve 5, the second electric valve 6, the third electric valve 7, the fourth electric valve 8, the first electric three-way valve 16, and the second electric three-way valve 24. A temperature sensor 23 is provided at the air inlet and outlet of the wind tunnel heat exchanger 4, and the temperature sensor 23 is connected to the PID controller.

[0043] Wind tunnel heat exchanger circuit working principle:

[0044] This system operates under four extreme operating conditions. When operating under each operating condition, the outlet air temperature after the heat exchanger is required to be constant. At this time, the heat generated by the entire system is constant; that is, when operating under this condition, the cooling capacity of the refrigeration unit (or the heating capacity of the main heater) should be roughly fixed, and there is no need to consider the temperature fluctuations caused by changes in operating load.

[0045] In actual test, the system is in cooling or heating condition, and the manual mode selection is made on the operation screen;

[0046] Working principle of heat exchanger circuit cooling condition: See the working principle diagram of cooling condition above Figure 1 The working principle is as follows: turn off the main heater, and close the first electric valve 5 and the second electric valve 6 at the inlet and outlet of the main heater; the refrigeration unit in the freezer room provides a 50% glacial solution at -22 to -15°C (accuracy is ±0.5°C), and the water pump provides energy to exchange heat with the glacier in the wind tunnel system through the plate exchanger between the storage tanks, so that the glacial solution in the wind tunnel system is cooled to -17°C to 60°C (adjusted according to the actual temperature requirements of the test through the first electric three-way valve 16 on the unit side) and stored in 10m 3 The storage tank 22 performs PID adjustment on the first electric three-way valve 16 and the second electric three-way valve 24 according to the signal of the temperature sensor 23 after the heat exchanger 4, so as to achieve accurate adjustment of the supply liquid temperature; at this time, the supply liquid and the return liquid of the wind tunnel heat exchanger are mixed in proportion through the first electric three-way valve 16 and the second electric three-way valve 24 (PID adjustment is performed according to the supply liquid temperature sensor 23 before the heat exchanger 4), so that the supply liquid temperature and accuracy of the heat exchanger in the test hall meet the target requirements;

[0047] The relationship between the liquid supply temperature and the air outlet temperature of this wind tunnel heat exchanger is determined and set during on-site commissioning; when the wind tunnel load remains unchanged during the test, the air outlet temperature can be kept constant if the liquid supply temperature remains constant and the air volume remains unchanged.

[0048] Outlet air temperature control logic: The wind tunnel heat exchange system control adopts the control logic of constant water volume and variable liquid supply temperature. During system debugging, the relationship between the liquid supply temperature and the outlet air temperature of the heat exchanger is found out for linear adjustment. In order to accurately adjust the actual liquid supply temperature, in addition to providing the liquid supply temperature accuracy of the refrigeration unit, the first electric three-way valve 16 and the second electric three-way valve 24 configured in the system mix the liquid supply of the refrigeration unit with the return liquid of the heat exchanger to achieve the accuracy of the total liquid supply temperature of the heat exchanger.

[0049] Working principle of heat exchanger circuit heating condition:

[0050] See above for the working principle diagram of heating condition Figure 1 Its working principle is as follows: the refrigeration unit is not turned on, the third electric valve 7 and the fourth electric valve 8 behind the refrigeration system storage tank are closed, the system liquid circuit is switched to the heating system operation, and the heating unit can be adjusted steplessly according to the target liquid outlet temperature. The unit can automatically control the liquid outlet temperature and safety protection control to adapt to flow changes.

[0051] At this time, the supply liquid and the return liquid of the wind tunnel heat exchanger are mixed in proportion through the first electric three-way valve 16 (PID adjustment is performed according to the supply liquid temperature sensor 23 before the heat exchanger), so that the supply liquid temperature and accuracy of the heat exchanger 4 meet the target requirements;

[0052] Outlet air temperature control logic: The wind tunnel heat exchange system control adopts the control logic of constant water volume and variable supply liquid temperature. When debugging the system, the relationship between the supply liquid temperature and the outlet air temperature of the heat exchanger is found out for linear adjustment. In order to accurately adjust the actual supply liquid temperature, in addition to the supply liquid temperature accuracy of the main heater provided by the heating system, the first electric three-way valve 16 and the second electric three-way valve 24 configured in the system mix the supply liquid of the main heater with the return liquid of the heat exchanger to achieve the accuracy of the total supply liquid temperature of the heat exchanger.

[0053] The above three embodiments of the present invention are described in detail, but the above contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of application of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. Wind tunnel heat exchange system, characterized by: It comprises a heating system, a cooling system, a water supply pump and a wind tunnel heat exchanger, wherein the heating system comprises a main heater, a first electric valve and a second electric valve are respectively provided on the hot liquid supply pipe and the hot liquid return pipe of the heating system, a third electric valve and a fourth electric valve are respectively provided on the cold liquid supply pipe and the cold liquid return pipe of the cooling system, the hot liquid supply pipe and the cold liquid supply pipe are intersected to form a liquid supply pipe and connected to the liquid inlet of the wind tunnel heat exchanger, the hot liquid return pipe and the cold liquid return pipe are intersected to form a liquid return pipe and connected to the water outlet of the wind tunnel heat exchanger, the liquid supply pipe and the liquid return pipe are connected through an electric three-way valve, the water supply pump is arranged on the liquid return pipe, a water-water heat exchanger is provided between the cold liquid supply pipe and the liquid return pipe, and the liquid return pipe is provided with a normal pressure storage tank and the water-water heat exchanger in sequence along the liquid return direction; The refrigeration system comprises a refrigeration unit, a chilled water pump and a system constant pressure device, wherein the refrigeration unit, the chilled water pump and the system constant pressure device are connected in sequence; the chilled water pump is divided into three groups; There are two electric three-way valves, the first electric three-way valve is arranged between the atmospheric pressure storage tank and the water supply pump, and the second electric three-way valve is arranged between the water-water heat exchanger and the chilled water pump; The working principle of the cooling condition of the wind tunnel heat exchange system is as follows: the main heater is turned off, and the first electric valve and the second electric valve are turned off; the refrigeration unit provides a glacial solution, and the glacial solution is provided with energy by the chilled water pump and passes through the plate exchanger in the atmospheric pressure storage tank to perform heat exchange with the glacial solution in the atmospheric pressure storage tank. After the glacial solution is cooled, it is stored in the atmospheric pressure storage tank. The first electric three-way valve and the second electric three-way valve are PID-regulated to achieve precise regulation of the supply liquid temperature. At this time, the supply liquid and the return liquid of the wind tunnel heat exchanger are proportionally mixed through the electric three-way valve, so that the supply liquid temperature and accuracy of the heat exchanger meet the target requirements; The working principle of the heating condition of the wind tunnel heat exchange system is as follows: the refrigeration unit is turned off, and the third electric valve and the fourth electric valve are turned off; the main heater can be adjusted steplessly according to the target outlet liquid temperature to adapt to the flow change and automatically control the outlet liquid temperature. At this time, the supply liquid and the return liquid of the wind tunnel heat exchanger are mixed in proportion through the first electric three-way valve, so that the supply liquid temperature and accuracy of the heat exchanger meet the target requirements.

2. The wind tunnel heat exchange system according to claim 1, characterized in that: The water outlet of the main heater is connected to the hot liquid supply pipe, the water inlet of the main heater is connected to the hot liquid return pipe, and a pressure storage tank is provided on the road between the second electric valve and the main heater.

3. The wind tunnel heat exchange system according to claim 1, characterized in that: There are four groups of water supply pumps.

4. The wind tunnel heat exchange system according to any one of claims 1 to 3, characterized in that: The system further includes a PID controller, which accurately controls the reflux volume of the first electric valve, the second electric valve, the third electric valve, the fourth electric valve, the first electric three-way valve, and the second electric three-way valve.

5. The wind tunnel heat exchange system according to claim 4, characterized in that: A temperature sensor is provided at the air inlet and outlet of the wind tunnel heat exchanger, and the temperature sensor is connected to the PID controller.

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