Helicopter air circulation system and control method thereof

Abstract

The present application belongs to the technical field of helicopter environmental control, and particularly relates to a helicopter air circulation system and a control method thereof. The system comprises an engine, an absolute pressure regulator, a shut-off valve, a flow limiting device, a refrigeration bleed air control valve, a combined radiator, a fan, a turbine cooler, a condenser, a high-pressure water separator, an anti-icing bleed air control valve, a warming bleed air control valve, an air distribution valve, and a condensate water injection pipe. The system and method can ensure that the engine bleed air amount is reduced from 720 kg / h to 450 kg / h, saving 37.5% of the bleed air amount, while the refrigeration capacity is increased by nearly 25%. The system water removal efficiency is increased from 65% to 95%, so that the air entering the cabin does not contain liquid condensate water. The warming control responds quickly, and the maximum temperature entering the cabin can reach above 80℃.

Description

Technical Field

[0001] This invention belongs to the field of helicopter environmental control technology, specifically relating to a helicopter air circulation system and its control method. Background Technology

[0002] The current helicopter environmental control system is a simple air circulation system configuration. This configuration uses high-temperature, high-pressure air from the engine's P3 stage, cools and depressurizes it, and delivers suitable air into the cabin to provide a good working microenvironment for the helicopter pilot and crew. Its principle is described as follows: High-temperature, high-pressure air is introduced from the engine, and the pressure is stabilized at a certain value by an absolute pressure regulator. Flow is limited by a venturi tube, and the flow rate is controlled at 720 kg / h. The high-temperature, high-pressure gas is processed in three paths. The first path is cooled by the hot side of the combined radiator and then enters the turbine for expansion and cooling to 4°C. The second path enters the cold side outlet of the combined radiator, drawing in ambient air to cool the air at the hot side of the radiator. The third path connects to a hot-circuit control valve, which regulates the flow rate and mixes it with the cold air at the turbine outlet of the first path. The temperature of the mixture is controlled between 10°C and 80°C. The mixed air then enters a low-pressure water separator and is sent into the cabin to regulate the cabin's ambient temperature.

[0003] Existing shortcomings:

[0004] a) This configuration draws 720 kg / h of bleed air from the engine, of which 360 kg / h enters the cabin and the remaining bleed air is used to bleed ambient air to cool the bleed air in the combined radiator; the engine bleed air efficiency is only about 50%, and the maximum cooling and heating capacity is limited.

[0005] b) During cooling operation, this configuration achieves a maximum water removal efficiency of only 65%, resulting in poor water removal and impacting cooling performance. Furthermore, in extreme high-temperature and high-humidity environments, liquid condensate is prone to entering the cabin from the system outlet during cooling operation.

[0006] c) When this configuration is heating, the temperature control response is slow. In the high-altitude low-temperature environment, the maximum temperature of the air entering the cabin is only 60°C, which fails to achieve the effect of rapid heating. Summary of the Invention

[0007] The purpose of this invention is to propose a helicopter air circulation system and its control method to solve the problems existing in the background technology.

[0008] The technical solution of the present invention:

[0009] A helicopter air circulation system includes an engine 1, and also includes an absolute pressure regulator, a shut-off valve 2, a flow limiting device 3, a cooling bleed air control valve 4, a combined radiator 5, a fan 6, a turbine cooler 7, a condenser 8, a high-pressure water separator 9, an anti-icing bleed air control valve 10, a heating bleed air control valve 11, an air distribution valve 12, and a condensate spray pipe 18.

[0010] Engine 1 is connected to the inlet end of the absolute pressure regulator. The outlet end of the absolute pressure regulator is connected in sequence to the shut-off valve 2 and the flow limiting device 3. The outlet end of the flow limiting device 3 is connected to the inlet ends of the refrigeration bleed air control valve 4, the anti-icing bleed air control valve 10, and the heating bleed air control valve 11, respectively.

[0011] The outlet end of the cooling vent control valve 4 is connected to the inlet end of the combined radiator 5, and the outlet end of the combined radiator 5 is connected to the inlet end of the condenser 8; the hot gas outlet end of the condenser 8 is connected to the inlet end of the high-pressure water separator 9, the gas outlet end of the high-pressure water separator 9 is connected to the turbine cooler 7, and the drain end of the high-pressure water separator 9 is connected to the condensate spray pipe 18, which is directly opposite the combined radiator 5.

[0012] The outlet end of the anti-icing air bleed control valve 10 is connected to the anti-icing chamber of the turbine cooler 7, and the anti-icing chamber of the turbine cooler 7 is connected to the inlet end of the condenser 8; the turbine cooler 7 is connected to the fan 6, and the turbine cooler 7 performs work on the fan 6.

[0013] The outlet end of the heating and induced draft control valve 11 is connected to the cold air outlet end of the condenser 8, and the cold air outlet end of the condenser 8 is connected to the air distribution valve 12.

[0014] Furthermore, a medium-temperature sensor 15 is provided on the connecting pipe between the combined radiator 5 and the condenser 8.

[0015] Furthermore, a pressure sensor 13 and a bleed air temperature sensor 14 are installed on the connecting pipeline between the shut-off valve 2 and the flow limiting device 3.

[0016] Furthermore, a pressure sensor 13 and a medium-temperature sensor 15 are installed on the connecting pipe between the outlet of the high-pressure water separator 9 and the turbine cooler 7.

[0017] Furthermore, a speed sensor 16 is installed on the connecting pipe between the turbine cooler 7 and the fan 6.

[0018] Furthermore, a medium-temperature sensor 15 and a temperature relay 17 are installed on the connecting pipe between the cold air outlet end of the condenser 8 and the air distribution valve 12.

[0019] Control methods for helicopter air circulation systems include cabin cooling control methods, cabin heating control methods, and anti-icing control methods.

[0020] Furthermore, the cabin cooling control method is as follows: The cooling bleed air control valve 4 is fully opened, and one stream of gas enters the combined radiator 5 after passing through the cooling bleed air control valve 4. The combined radiator 5 is cooled at its hot side. The anti-icing bleed air control valve 10 is opened, and another stream of gas enters the condenser 8 through the anti-icing chamber of the cooler 7. By controlling the opening of the anti-icing bleed air control valve 10, the temperature of the anti-icing chamber is controlled at 4°C. The heating bleed air control valve 11 is closed, and the gas from the outlet of the combined radiator 5 mixes with the gas from the outlet of the anti-icing chamber of the cooler 7 and enters the condenser 8 for further cooling. The mixed air is then distributed to the cabin by the air distribution valve 12, achieving maximum system cooling control.

[0021] When the system set temperature is higher than the actual temperature, open the heating induced draft control valve 11, and fine-tune the opening of the heating induced draft control valve 11 to control the air supply temperature.

[0022] Furthermore, the cabin heating control method is as follows: The cooling bleed air control valve 4 is opened, and one stream of gas enters the combined radiator 5 after passing through the cooling bleed air control valve 4, where it is cooled at the hot side. The anti-icing bleed air control valve 10 is opened, and another stream of gas enters the condenser 8 through the anti-icing chamber of the cooler 7. By controlling the opening of the anti-icing bleed air control valve 10, the temperature of the anti-icing chamber is controlled at 4°C. The heating bleed air control valve 11 is continuously opened, and the cabin temperature gradually increases. When the heating bleed air control valve 11 is fully open, and the actual cabin temperature is still lower than the set temperature, the opening of the cooling bleed air control valve 4 is gradually closed to control the air supply temperature.

[0023] Furthermore, the anti-icing control method is as follows:

[0024] Open the anti-icing bleed air control valve 10, and the gas enters the anti-icing chamber at the outlet of the turbine cooler 7 through the anti-icing bleed air control valve 10. By collecting the temperature of the anti-icing chamber of the turbine cooler 7, the opening of the anti-icing bleed air control valve 10 is finely adjusted to control the temperature of the mixed gas at 4°C to prevent ice blockage caused by icing at the cold side inlet of the condenser 8.

[0025] Beneficial effects of the present invention: The present invention provides a helicopter air circulation system and its control method, which has the following advantages:

[0026] a) Cabin cooling function: Fully open cooling bleed air control valve 4, adjust the opening of anti-icing bleed air control valve 10 to control the anti-icing cavity temperature to 4℃, close heating bleed air control valve 11 to achieve the maximum cooling capacity of the system. When the system set temperature is higher than the actual temperature, open heating bleed air control valve 11 and fine-tune the opening of heating bleed air control valve 11 to control the air supply temperature.

[0027] b) Cabin heating function: Fully open the cooling bleed air control valve 4, adjust the opening of the anti-icing bleed air control valve 10 to control the anti-icing cavity temperature to 4°C, and continuously open the heating bleed air control valve 11 to gradually increase the cabin temperature. When the heating bleed air control valve 11 is fully open and the actual cabin temperature is still lower than the set temperature, gradually close the opening of the cooling bleed air control valve 4 to control the air supply temperature.

[0028] c) Anti-icing function: By collecting the temperature of the anti-icing chamber of the turbine cooler 7, the opening of the anti-icing bleed air control valve 10 is finely adjusted to control the mixing temperature to 4℃, thereby achieving the anti-icing function.

[0029] In summary, the system and method of the present invention can reduce the engine bleed air volume from 720 kg / h to 450 kg / h, saving 37.5% of the bleed air volume, while increasing the cooling capacity by nearly 25%; the system dewatering efficiency is increased from 65% to 95%, ensuring that the air entering the cabin is free of liquid condensate; the heating control has a rapid response, and the maximum cabin temperature can reach over 80°C. Attached Figure Description

[0030] Figure 1 Schematic diagram of the cooling control principle for the air circulation system compartment;

[0031] Figure 2 Schematic diagram of cabin heating control principle for air circulation system;

[0032] Among them, 1 is the engine, 2 is the shut-off valve, 3 is the flow limiting device, 4 is the refrigeration bleed air control valve, 5 is the combined radiator, 6 is the fan, 7 is the turbine cooler, 8 is the condenser, 9 is the high-pressure water separator, 10 is the anti-icing bleed air control valve, 11 is the heating bleed air control valve, 12 is the air distribution valve, 13 is the bleed air pressure sensor, 14 is the bleed air temperature sensor, 15 is the medium temperature sensor, 16 is the speed sensor, 17 is the temperature relay, and 18 is the condensate spray pipe. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] like Figure 1 , 2As shown, a helicopter air circulation system includes an absolute pressure regulator and shut-off valve 2, a flow limiting device 3, a cooling bleed air control valve 4, a combined radiator 5, a fan 6, a turbine cooler 7, a condenser 8, a high-pressure water separator 9, an anti-icing bleed air control valve 10, a heating bleed air control valve 11, an air distribution valve 12, a pressure sensor 13, a bleed air temperature sensor 14, a medium temperature sensor 15, a speed sensor 16, a temperature relay 17, and a condensate spray nozzle 18.

[0035] In this invention, the inlet end of the absolute pressure regulator and shut-off valve 2 is connected to the bleed air port of the engine 1, and the outlet end is connected to the inlet end of the flow limiting device 3. A bleed air pressure sensor 13 and a bleed air temperature sensor 14 are provided on the connecting pipeline between the absolute pressure regulator, shut-off valve 2, and flow limiting device 3. The absolute pressure regulator and shut-off valve 2 are used to control the opening and closing of the engine bleed air and to regulate the pressure, while the flow limiting device 3 is used to control the engine bleed air volume to not exceed the maximum allowable amount.

[0036] In this invention, the outlet end of the flow limiting device 3 is connected to the inlet ends of the refrigeration bleed air control valve 4, the anti-icing bleed air control valve 10, and the heating bleed air control valve 11, respectively. The refrigeration bleed air control valve 4 is used to control the bleed air volume of the refrigeration circuit, the anti-icing bleed air control valve 10 is used to prevent icing in the turbine anti-icing chamber and the cold side inlet of the condenser 8, and the heating bleed air control valve 11 is used to control the heating bleed air volume.

[0037] In this invention, the outlet end of the refrigeration venting control valve 4 is connected to the inlet end of the combined radiator 5, and the outlet end of the combined radiator 5 is connected to the inlet end of the condenser 8. A medium-temperature sensor 15 is provided on the connecting pipe between the combined radiator 5 and the condenser 8.

[0038] In this invention, the hot gas outlet end of the condenser 8 is connected to the inlet end of the high-pressure water separator 9, the gas outlet end of the high-pressure water separator 9 is connected to the turbine cooler 7, a pressure sensor 13 and a medium temperature sensor 15 are provided on the connecting pipe between the high-pressure water separator 9 and the turbine cooler 7, and the drain end of the high-pressure water separator 9 is connected to the condensate spray pipe 18.

[0039] In this invention, the outlet end of the anti-icing bleed air control valve 10 is connected to the anti-icing cavity of the turbine cooler 7.

[0040] In this invention, the outlet end of the heating and induced draft control valve 11 is connected to the cold air outlet end of the condenser 8.

[0041] In this invention, the cold air outlet of the condenser 8 is connected to the air distribution valve 12. A medium-temperature sensor 15 and a temperature relay 17 are provided on the pipeline connecting the cold air outlet of the condenser 8 to the air distribution valve 12.

[0042] In this invention, the turbine cooler 7 is connected to the fan 6, the turbine cooler 7 performs work on the fan 6, and a speed sensor 16 is provided on the connecting shaft between the turbine cooler 7 and the fan 6.

[0043] Its principle is as follows Figure 1 , 2 As shown, during system operation: high-temperature, high-pressure air is introduced from engine 1, and the pressure is stabilized within a certain range by the absolute pressure regulator and shut-off valve 2. The flow is limited by the flow limiting device 3, and the flow rate is controlled at around 450 kg / h. The engine bleed air is processed in three paths:

[0044] The first gas stream enters the combined radiator 5 after passing through the refrigeration bleed control valve 4. The gas is cooled at the hot side of the combined radiator 5 and then enters the condenser 8 for further cooling. During this process, water is condensed from the gaseous state and the condensate is sprayed onto the combined radiator 5 through the condensate spray pipe 18, further enhancing the heat dissipation capacity of the combined radiator 5. The air enters the high-pressure water separator 9 for gas-liquid separation and then expands and cools to -40°C in the turbine cooler 7, thus achieving cabin cooling control.

[0045] The second airflow enters the anti-icing chamber at the outlet of the turbine cooler 7 through the anti-icing bleed air control valve 10. This airflow is used to mix the cold air at the outlet of the turbine cooler 7, preventing ice blockage at the cold side inlet of the condenser 8 and thus achieving anti-icing control.

[0046] The third connection is to the heating bleed air control valve 11. After the flow rate is adjusted by the heating bleed air control valve 11, it is mixed with the cold air at the cold side outlet of the condenser 8. The temperature of the mixed air is controlled between 10℃ and 80℃. The mixed air is distributed to the cabin by the air distribution valve 12 to achieve cabin heating control.

[0047] This type of air circulation system specifically achieves the following functions:

[0048] a) Cabin cooling function: Fully open cooling bleed air control valve 4, adjust the opening of anti-icing bleed air control valve 10 to control the anti-icing cavity temperature to 4℃, close heating bleed air control valve 11 to achieve the maximum cooling capacity of the system. When the system set temperature is higher than the actual temperature, open heating bleed air control valve 11 and fine-tune the opening of heating bleed air control valve 11 to control the air supply temperature.

[0049] b) Cabin heating function: Fully open the cooling bleed air control valve 4, adjust the opening of the anti-icing bleed air control valve 10 to control the anti-icing cavity temperature to 4°C, and continuously open the heating bleed air control valve 11 to gradually increase the cabin temperature. When the heating bleed air control valve 11 is fully open and the actual cabin temperature is still lower than the set temperature, gradually close the opening of the cooling bleed air control valve 4 to control the air supply temperature.

[0050] c) Anti-icing function: By collecting the temperature of the anti-icing chamber of the turbine cooler 7, the opening of the anti-icing bleed air control valve 10 is finely adjusted to control the mixing temperature to 4℃, thereby achieving the anti-icing function.

[0051] The system and method of the present invention can reduce the engine bleed air volume from 720 kg / h to 450 kg / h, saving 37.5% of the bleed air volume, while increasing the cooling capacity by nearly 25%; the system dewatering efficiency is increased from 65% to 95%, ensuring that the air entering the cabin does not contain liquid condensate; the heating control has a fast response, and the maximum cabin temperature can reach over 80°C.

[0052] The above description is merely a specific embodiment of the present invention, providing a detailed description of the invention. Parts not covered herein are conventional techniques. However, the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A helicopter air circulation system, comprising an engine (1), characterized in that: It also includes an absolute pressure regulator, a shut-off valve (2), a flow limiting device (3), a refrigeration bleed air control valve (4), a combined radiator (5), a fan (6), a turbine cooler (7), a condenser (8), a high-pressure water separator (9), an anti-icing bleed air control valve (10), a heating bleed air control valve (11), an air distribution valve (12), and a condensate spray pipe (18). The engine (1) is connected to the inlet end of the absolute pressure regulator, and the outlet end of the absolute pressure regulator is connected to the shut-off valve (2) and the flow limiting device (3) in sequence. The outlet end of the flow limiting device (3) is connected to the inlet ends of the refrigeration bleed air control valve (4), the anti-icing bleed air control valve (10), and the heating bleed air control valve (11), respectively. The outlet end of the cooling vent control valve (4) is connected to the inlet end of the combined radiator (5), and the outlet end of the combined radiator (5) is connected to the inlet end of the condenser (8); the hot gas outlet end of the condenser (8) is connected to the inlet end of the high-pressure water separator (9), the gas outlet end of the high-pressure water separator (9) is connected to the turbine cooler (7), and the drain end of the high-pressure water separator (9) is connected to the condensate spray pipe (18), which is directly opposite the combined radiator (5). The outlet end of the anti-icing air bleed control valve (10) is connected to the anti-icing chamber of the turbine cooler (7), and the anti-icing chamber of the turbine cooler (7) is connected to the inlet end of the condenser (8); the turbine cooler (7) is connected to the fan (6), and the turbine cooler (7) performs work on the fan (6). The outlet end of the heating and induced draft control valve (11) is connected to the cold air outlet end of the condenser (8), and the cold air outlet end of the condenser (8) is connected to the air distribution valve (12).

2. The helicopter air circulation system according to claim 1, characterized in that, A medium-temperature sensor (15) is installed on the connecting pipe between the combined radiator (5) and the condenser (8).

3. The helicopter air circulation system according to claim 1, characterized in that, A pressure sensor (13) and a bleed air temperature sensor (14) are installed on the connecting pipeline between the shut-off valve (2) and the flow limiting device (3).

4. A helicopter air circulation system according to claim 1, characterized in that, A pressure sensor (13) and a medium-temperature sensor (15) are installed on the connecting pipe between the outlet of the high-pressure water separator (9) and the turbine cooler (7).

5. A helicopter air circulation system according to claim 1, characterized in that, A speed sensor (16) is installed on the connecting pipe between the turbine cooler (7) and the fan (6).

6. A helicopter air circulation system according to claim 1, characterized in that, A medium-temperature sensor (15) and a temperature relay (17) are installed on the connecting pipe between the cold air outlet end of the condenser (8) and the air distribution valve (12).

7. The control method for the helicopter air circulation system according to any one of claims 1-6, characterized in that, This includes cabin cooling control methods, cabin heating control methods, and anti-icing control methods.

8. The control method for a helicopter air circulation system according to claim 7, characterized in that, The cabin cooling control method is as follows: the cooling bleed air control valve (4) is fully opened, one gas enters the combined radiator (5) after passing through the cooling bleed air control valve (4), and is cooled at the hot side of the combined radiator (5). The anti-icing bleed air control valve (10) is opened, and another gas enters the condenser (8) through the anti-icing cavity of the cooler (7). The temperature of the anti-icing cavity is controlled to 4°C by controlling the opening of the anti-icing bleed air control valve (10). The heating bleed air control valve (11) is closed. The gas at the outlet of the combined radiator (5) and the gas at the outlet of the anti-icing cavity of the cooler (7) are mixed and enter the condenser (8) for further cooling. The mixed air is distributed to the cabin by the air distribution valve (12). To achieve maximum cooling control of the system, the mixed air is distributed to the cabin by the air distribution valve (12); When the system set temperature is higher than the actual temperature, open the heating induced draft control valve (11), fine-tune the opening of the heating induced draft control valve (11), and control the air supply temperature.

9. The control method for a helicopter air circulation system according to claim 7, characterized in that, The cabin heating control method is as follows: Open the cooling bleed air control valve (4), one gas enters the combined radiator (5) after passing through the cooling bleed air control valve (4), and is cooled at the hot side of the combined radiator (5). Open the anti-icing bleed air control valve (10), and another gas enters the condenser (8) through the anti-icing cavity of the cooler (7). By controlling the opening of the anti-icing bleed air control valve (10), the temperature of the anti-icing cavity is controlled to 4°C. The heating bleed air control valve (11) is continuously opened, and the cabin temperature gradually increases. When the heating bleed air control valve (11) is fully open, and the actual cabin temperature is still lower than the set temperature, the opening of the cooling bleed air control valve (4) is gradually closed to control the air supply temperature.

10. The control method for a helicopter air circulation system according to claim 7, characterized in that, The aforementioned anti-icing control method is as follows: Open the anti-icing bleed air control valve (10), and the gas enters the anti-icing chamber at the outlet of the turbine cooler (7) through the anti-icing bleed air control valve (10). By collecting the temperature of the anti-icing chamber of the turbine cooler (7), the opening of the anti-icing bleed air control valve (10) is finely adjusted to control the temperature of the mixed gas to 4°C to prevent ice blockage caused by icing at the cold side inlet of the condenser (8).

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