阅读说明：本技术 一种低温来流工质高精度供应系统及方法 (High-precision supply system and method for low-temperature incoming flow working medium ) 是由 董冬 王栋 沈继彬 史雪梅 乔江晖 张洪春 于 2021-07-28 设计创作，主要内容包括：本发明涉及一种低温来流工质高精度供应系统及方法,以解决现有发动机试验中,为发动机燃烧室供应低温空气的供应管路因结冰堵塞不能正常供应,且难以将供应的空气维持在要求的温度和流量范围内的问题。该系统包括空气源单元、空气干燥单元、空气调节阀单元、第一三通、空气辅路供应单元、低温换热单元、第二三通及掺混单元。空气源单元输出常温高压空气并送入空气干燥单元,空气干燥单元对常温高压空气进行干燥,并通过空气调节阀单元进行流量调节,所输出的空气通过第一三通分别进入空气辅路供应单元和低温换热单元,空气辅路供应单元输出的常温空气和低温换热单元输出的低温空气通过第二三通汇合后进入混掺单元进行混掺,并送入发动机燃烧室。(The invention relates to a high-precision supply system and method for low-temperature incoming flow working media, which aim to solve the problems that a supply pipeline for supplying low-temperature air to an engine combustion chamber cannot be normally supplied due to icing and blockage in the existing engine test, and the supplied air is difficult to maintain in a required temperature and flow range. The system comprises an air source unit, an air drying unit, an air regulating valve unit, a first tee joint, an air auxiliary path supply unit, a low-temperature heat exchange unit, a second tee joint and a mixing unit. The air source unit outputs normal-temperature high-pressure air and sends the air to the air drying unit, the air drying unit dries the normal-temperature high-pressure air and carries out flow regulation through the air regulating valve unit, the output air respectively enters the air auxiliary path supply unit and the low-temperature heat exchange unit through a first tee joint, the normal-temperature air output by the air auxiliary path supply unit and the low-temperature air output by the low-temperature heat exchange unit are converged through a second tee joint and then enter the blending unit for blending, and the blended air is sent to the engine combustion chamber.)

1. A high-precision supply system for low-temperature incoming flow working medium is characterized in that:

comprises an air source unit (1), an air drying unit (2), an air regulating valve unit (3), a first tee joint, an air auxiliary path supply unit (4), a low-temperature heat exchange unit (5), a second tee joint and a mixing unit (6);

the air source unit (1) is used for outputting normal-temperature high-pressure air and sending the air into the air drying unit (2);

the air drying unit (2) comprises an inlet pipeline, a dryer (21) and an outlet pipeline which are connected in sequence;

the air regulating valve unit (3) comprises an air reducing valve (31), a first manual stop valve (32), a first electric control pressure regulating valve (33) and a first throttling orifice plate (34) which are connected in sequence; the inlet of the air reducing valve (31) is connected with an outlet pipeline of the air drying unit (2); a mass flowmeter, a pressure sensor and a temperature sensor are arranged between the first electric control pressure regulating valve (33) and the first throttling orifice plate (34); the outlet of the first throttling orifice plate (34) is connected with the inlet end of the first tee joint;

the air auxiliary supply unit (4) comprises a second electrically controlled pressure regulating valve (41); the inlet of the second electric control pressure regulating valve (41) is connected with one outlet end of the first tee joint, and the outlet of the second electric control pressure regulating valve is connected with one inlet end of the second tee joint;

the low-temperature heat exchange unit (5) comprises a second manual stop valve (51), a heat exchanger (52) and a second orifice plate (53) which are connected in sequence; the inlet of the second manual stop valve (51) is connected with the other outlet end of the first tee joint; a pressure sensor and a temperature sensor are arranged between the heat exchanger (52) and the second throttling orifice plate (53); the outlet of the second throttling orifice plate (53) is connected with the other inlet end of the second tee joint;

and the inlet of the blending unit (6) is connected with the outlet end of the second tee joint and is used for blending the normal-temperature air output by the air auxiliary path supply unit (4) and the low-temperature air output by the low-temperature heat exchange unit (5) and sending the blended air into a combustion chamber of the engine.

2. The high-precision supply system for low-temperature incoming flow working medium according to claim 1, characterized in that:

the air source unit (1) comprises an air compressor (11) and a high-pressure air bottle (12); the air compressor (11) compresses air and sends the air to the high-pressure air bottle (12) for storage; the high-pressure air bottle (12) outputs normal-temperature high-pressure air with the pressure not greater than 30MPa and sends the air into an inlet pipeline of the air drying unit (2).

3. The high-precision supply system for low-temperature incoming flow working medium according to claim 2, characterized in that:

the dryer (21) is internally provided with an alumina gel adsorption drying agent.

4. The high-precision supply system for low-temperature incoming flow working medium according to claim 3, characterized in that:

the heat exchanger (52) is a stainless steel cylindrical shell-and-tube heat exchanger.

5. The high-precision supply system for low-temperature incoming fluid working medium according to any one of claims 1 to 4, characterized in that:

and the heat exchange working medium supply unit is used for supplying liquid nitrogen to the heat exchanger (52).

6. The high-precision supply system for low-temperature incoming flow working medium according to claim 5, characterized in that:

the flow range of the air reducing valve (31) is 0-1 kg/s.

7. The high-precision supply system for low-temperature incoming flow working medium according to claim 6, characterized in that:

the orifice size of the first orifice plate (34) is 4 mm;

the orifice size of the second orifice plate (53) is 8 mm.

8. A high-precision supply method for low-temperature incoming flow working medium, which adopts the high-precision supply system for low-temperature incoming flow working medium of any one of claims 1 to 7, and is characterized by comprising the following steps:

1) opening a first manual stop valve (32) and a second manual stop valve (51), outputting normal-temperature high-pressure air with the pressure not more than 30MPa by the air source unit (1) and sending the air into the air drying unit (2);

2) drying the normal-temperature high-pressure air by a dryer (21) to generate normal-temperature high-pressure dry air with the dew point not higher than-64 ℃;

3) the normal-temperature high-pressure dry air is subjected to pressure stabilization through an air reducing valve (31), and then is subjected to flow regulation through a first electronic control pressure regulating valve (33) and a first throttling orifice plate (34) in sequence; the flow regulating range is 0.041-0.220 kg/s;

4) dividing the normal-temperature high-pressure dry air subjected to flow regulation into two paths; one path of the air flow rate is regulated at normal temperature through a second electric control pressure regulating valve (41); the other path of the air is subjected to heat exchange through a heat exchanger (52) to generate low-temperature air with the temperature lower than the temperature required by a combustion chamber of the engine, and then the low-temperature air flow is regulated through a second throttling orifice plate (53);

5) the normal temperature air output by the air auxiliary path supply unit (4) and the low temperature air output by the low temperature heat exchange unit (5) are mixed and sent to the engine combustion chamber.

Technical Field

The invention relates to the field of engine tests, in particular to a low-temperature incoming flow working medium high-precision supply system and method.

Background

In an engine test, according to the test technical requirements, low-temperature air needs to be supplied to an engine combustion chamber, the supply flow rate is controlled within the range of 0.041-0.220 kg/s, and the temperature is controlled at 217K (-56 ℃). The low-temperature air supply has not much technical accumulation in the current engineering application and literature data, and the low-temperature incoming air supply also has certain technical difficulty: on one hand, air is easy to freeze at low temperature (-30 ℃), and the air cannot be normally supplied after the supply pipeline is blocked due to freezing; on the other hand, maintaining the supplied air within the required temperature and flow range is also a technical difficulty. Therefore, it is necessary to develop a high-precision supply system for low-temperature incoming fluid.

Disclosure of Invention

The invention aims to solve the problems that a supply pipeline for supplying low-temperature air to an engine combustion chamber cannot normally supply the low-temperature air due to icing and blockage in the existing engine test and the supplied air is difficult to maintain in a required temperature and flow range, and provides a high-precision supply system and method for low-temperature incoming flow working medium.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a high-precision supply system for low-temperature incoming flow working media is characterized in that:

the system comprises an air source unit, an air drying unit, an air regulating valve unit, a first tee joint, an air auxiliary path supply unit, a low-temperature heat exchange unit, a second tee joint and a mixing unit;

the air source unit is used for outputting normal-temperature high-pressure air and sending the air into the air drying unit;

the air drying unit comprises an inlet pipeline, a dryer and an outlet pipeline which are connected in sequence;

the air regulating valve unit comprises an air reducing valve, a first manual stop valve, a first electric control pressure regulating valve and a first orifice plate which are connected in sequence; the inlet of the air pressure reducing valve is connected with an outlet pipeline of the air drying unit; a mass flowmeter, a pressure sensor and a temperature sensor are arranged between the first electric control pressure regulating valve and the first throttling orifice plate; the outlet of the first orifice plate is connected with the inlet end of the first tee joint;

the air auxiliary path supply unit comprises a second electric control pressure regulating valve; the inlet of the second electric control pressure regulating valve is connected with one outlet end of the first tee joint, and the outlet of the second electric control pressure regulating valve is connected with one inlet end of the second tee joint;

the low-temperature heat exchange unit comprises a second manual stop valve, a heat exchanger and a second throttling orifice plate which are connected in sequence; the inlet of the second manual stop valve is connected with the other outlet end of the first tee joint; a pressure sensor and a temperature sensor are arranged between the heat exchanger and the second throttling orifice plate; the outlet of the second orifice plate is connected with the other inlet end of the second tee joint;

and the inlet of the mixing unit is connected with the outlet end of the second tee joint and is used for mixing the normal-temperature air output by the air auxiliary path supply unit and the low-temperature air output by the low-temperature heat exchange unit and sending the mixed air into the engine combustion chamber.

Further, the air source unit comprises an air compressor and a high-pressure air bottle; the air compressor compresses air and sends the air into a high-pressure air bottle for storage; and the high-pressure air bottle outputs normal-temperature high-pressure air of not more than 30MPa and sends the air into an inlet pipeline of the air drying unit.

Furthermore, an aluminum gel adsorption drying agent is arranged in the dryer.

Further, the heat exchanger is a stainless steel cylindrical shell-and-tube heat exchanger.

Further, the heat exchanger also comprises a heat exchange working medium supply unit for supplying liquid nitrogen to the heat exchanger.

Furthermore, the flow range of the air reducing valve is 0-1 kg/s.

Further, the orifice size of the first orifice plate is 4 mm;

the orifice plate size of the second orifice plate is 8 mm.

A low-temperature incoming flow working medium high-precision supply method adopts the low-temperature incoming flow working medium high-precision supply system and is characterized by comprising the following steps:

1) opening the first manual stop valve and the second manual stop valve, and outputting normal-temperature high-pressure air with the pressure not more than 30MPa by the air source unit and sending the air into the air drying unit;

2) drying the normal-temperature high-pressure air by a dryer to generate normal-temperature high-pressure dry air with the dew point not higher than-64 ℃;

3) the normal-temperature high-pressure dry air is subjected to pressure stabilization through an air pressure reducing valve, and then flow regulation is performed through a first electric control pressure regulating valve and a first throttling orifice plate in sequence; the flow regulating range is 0.041-0.220 kg/s;

4) dividing the normal-temperature high-pressure dry air subjected to flow regulation into two paths; one path of the air flow regulating valve is used for regulating the air flow at the normal temperature through a second electric control pressure regulating valve; the other path of the air is subjected to heat exchange through a heat exchanger to generate low-temperature air with the temperature lower than the temperature required by the engine combustion chamber, and then the low-temperature air flow is regulated through a second throttling orifice plate;

5) the normal temperature air output by the air auxiliary path supply unit and the low temperature air output by the low temperature heat exchange unit are mixed and sent to the engine combustion chamber.

The invention has the beneficial effects that:

the invention provides a high-precision supply system and method for low-temperature incoming flow working media, which adjust the total flow of supply air through a first electric control pressure regulating valve and a first throttle orifice plate, control the total flow of the supply air within the range of 0.041-0.220 kg/s, and respectively adjust the flow of normal-temperature air and the flow of low-temperature air through a second electric control pressure regulating valve and a second throttle orifice plate, so as to ensure that the temperature of the mixed air is controlled at 217K (-56 ℃), realize stable low-temperature air supply, and the air is dried and free from icing.

Drawings

FIG. 1 is a schematic structural diagram of a high-precision supply system for low-temperature incoming flow working medium.

In the figure, 1-air source unit, 11-air compressor, 12-high pressure gas cylinder; 2-air drying unit, 21-dryer; 3-an air regulating valve unit, 31-an air reducing valve, 32-a first manual stop valve, 33-a first electric control pressure regulating valve and 34-a first throttling orifice plate; 4-air auxiliary circuit supply unit, 41-second electric control pressure regulating valve; 5-a low-temperature heat exchange unit, 51-a second manual stop valve, 52-a heat exchanger and 53-a second throttling orifice plate; 6-blending unit.

Detailed Description

In order to make the objects, advantages and features of the present invention more apparent, a system and a method for supplying low-temperature incoming fluid with high precision according to the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

The high-precision supply system of the low-temperature incoming flow working medium provided by the embodiment is shown in fig. 1, and comprises an air source unit 1, an air drying unit 2, an air regulating valve unit 3, a first tee joint, an air auxiliary path supply unit 4, a low-temperature heat exchange unit 5, a second tee joint and a mixing unit 6.

The air source unit 1 outputs normal-temperature high-pressure air, and the air is dried by the air drying unit 2, so that the air is not easy to freeze; then the total flow of air is regulated through the air regulating valve unit 3, and the total flow of air supply is ensured to be maintained in the range required by the test; and then the supplied air is divided into two paths, wherein the low-temperature heat exchange unit 5 exchanges heat with the air to generate low-temperature air, and the low-temperature air is mixed with the normal-temperature air output by the air auxiliary path supply unit 4 to obtain the air with the temperature required by the test and is sent into the engine combustion chamber.

Specifically, the air source unit 1 comprises an air compressor 11 and a high-pressure air bottle 12, the air compressor 11 compresses air and sends the compressed air into the high-pressure air bottle 12 for storage, and the high-pressure air bottle 12 outputs normal-temperature high-pressure air with the pressure not greater than 30MPa and sends the normal-temperature high-pressure air into the air drying unit 2.

The air drying unit 2 comprises a stainless steel inlet pipeline, a dryer 21 filled with an alumina gel adsorption drying agent and a stainless steel outlet pipeline which are connected in sequence. The normal-temperature high-pressure air output by the high-pressure air bottle 12 enters the dryer 21 through the inlet pipeline for drying treatment, and the dew point of the output normal-temperature high-pressure dry air reaches-64 ℃.

The air adjustment valve unit 3 includes an air reducing valve 31, a first manual cut-off valve 32, a first electrically controlled pressure regulating valve 33, and a first orifice plate 34, which are connected in this order. The inlet of the air pressure reducing valve 31 is connected with the outlet pipeline of the air drying unit 2 and used for stabilizing air pressure, and the flow range of the air pressure reducing valve is 0-1 kg/s. The first manual stop valve 32 is used to switch on and off the air supply of the section of pipeline. The first electric control pressure regulating valve 33 achieves the opening degree of a valve mechanical actuating mechanism by remotely controlling the value of the current of the valve electric cylinder, so that the air flow regulation is realized. A mass flow meter, a pressure sensor and a temperature sensor are arranged between the first electrically-controlled pressure regulating valve 33 and the first orifice plate 34 and represent the air flow, the pressure and the temperature of the section of pipeline. The outlet of the first orifice plate 34 is connected with the inlet end of the first tee joint, the orifice plate size of the first orifice plate 34 is 4mm, and the orifice plate is used for achieving high-pressure air flow adjustment and covering all flow working points (0.041-0.220 kg/s) through calculation. The connecting pipeline in the unit is made of DN20 stainless steel.

The air auxiliary supply unit 4 includes a second electrically controlled pressure regulating valve 41, an inlet of the second electrically controlled pressure regulating valve 41 being connected to one of outlet ends of the first three-way, and an outlet thereof being connected to one of inlet ends of the second three-way. The second electric control pressure regulating valve 41 achieves the opening degree of the mechanical actuating mechanism of the valve by remotely controlling the value of the current of the electric cylinder of the valve, so as to realize the air flow regulation. The connecting pipeline in the unit is made of DN20 stainless steel.

The low-temperature heat exchange unit 5 comprises a second manual stop valve 51, a heat exchanger 52 and a second orifice plate 53 which are connected in sequence. The inlet of the second manual stop valve 51 is connected with the other outlet end of the first tee joint for realizing the on-off of the air supply of the section of pipeline. The heat exchanger 52 is externally connected with a heat exchange working medium supply unit, and a pressure sensor and a temperature sensor are arranged between the heat exchanger 52 and the second orifice plate 53 and represent the pressure and the temperature of the pipeline at the section. The outlet of the second orifice plate 53 is connected with the other inlet end of the second tee joint, and the orifice plate size of the second orifice plate 53 is 8mm, so that the high-pressure air pressure is stabilized and boosted, and the heat exchange efficiency is improved. The connecting pipeline in the unit is made of DN20 stainless steel. The working principle of the low-temperature heat exchange unit 5 is as follows: liquid nitrogen is supplied through the heat exchange working medium supply unit, the liquid nitrogen flows, vaporizes, volatilizes and exchanges heat inside the heat exchanger 52, then normal-temperature air inside the heat exchanger 52 is cooled and exchanged heat, and low-temperature air with stable flow is output through the second throttling orifice 53 after heat exchange.

The heat exchanger 52 is a stainless steel cylindrical shell-and-tube heat exchanger, the length of the heat exchanger 52 is 2500mm, the outer diameter of the heat exchanger is 200mm, 10 stainless steel liquid nitrogen heat exchange tubes with the length of 7000mm and DN6 are embedded in the heat exchanger, the heat exchange tubes are spirally connected and arranged, the total length of the heat exchange tubes is 70000mm, the intervals between the wound tubes are 150mm, and the diameter of the wound tube bends is 125 mm. Two openings are respectively arranged at the upper end and the lower end of the outer wall of the shell, a normal-temperature air inlet and a liquid nitrogen emission outlet are arranged at the upper end of the outer wall of the shell, the liquid nitrogen emission outlet is connected with a stainless steel pipeline which is 4000mm long and DN20 long, the pipeline outlet is open, the volatilization emission of low-temperature working media is realized, and the liquid nitrogen emission outlet has deformation compensation capability. The lower end is provided with a liquid nitrogen inlet and a low-temperature air outlet, wherein the liquid nitrogen inlet is connected with the heat exchange working medium supply unit through a 6000mm long and DN20 stainless steel pipeline. The low-temperature air outlet is connected with a 6000mm stainless steel pipeline and a DN20 stainless steel pipeline and is converged with the air auxiliary path supply unit 4 through a second tee joint made of stainless steel. The heat exchanger 52, the low-temperature air outlet pipeline of the low-temperature heat exchange unit 5 and the liquid nitrogen conveying pipeline are coated with rubber-plastic sponge with the thickness of 5mm, and are wrapped and fixed by aluminum foil adhesive tapes to realize low-temperature keeping.

The heat exchange working medium supply unit comprises a low-temperature refrigeration storage tank, a self-circulation pressurization unit, a safety valve bank, an emergency cut-off valve and a manual regulating valve which are sequentially connected. The volume of the low-temperature refrigeration storage tank is 30m³. The manual regulating valve is used for realizing the flow control of liquid nitrogen, and the outlet of the manual regulating valve is connected with the liquid nitrogen inlet of the heat exchanger 52. The specification of a connecting pipeline in the unit is DN50, 16MPa, the stainless steel material is used for supplyingThe maximum liquid nitrogen flow was 1 kg/s.

The inlet of the mixing unit 6 is connected with the outlet end of the second tee joint and used for mixing the normal-temperature air output by the air auxiliary path supply unit 4 and the low-temperature air output by the low-temperature heat exchange unit 5, the outlet pipeline of the mixing unit 6 is connected with the combustion chamber of the engine, and a mass flow meter, a pressure sensor and a temperature sensor are arranged on the mixing unit and used for representing the air flow, the pressure and the temperature of the pipeline at the section. The mixed air is sent into the combustion chamber of the engine.

The high-precision supply method of the low-temperature incoming flow working medium based on the system comprises the following steps:

1) opening the first manual cut-off valve 32 and the second manual cut-off valve 51; the normal temperature and normal pressure air is compressed by an air compressor 11 and is sent into a high pressure air bottle 12 for storage, and the high pressure air bottle 12 outputs normal temperature and high pressure air with the pressure not more than 30MPa and sends the air into an inlet pipeline of an air drying unit 2;

2) drying the normal-temperature high-pressure air by a dryer 21 to generate normal-temperature high-pressure dry air with the dew point not higher than-64 ℃;

3) the normal-temperature high-pressure dry air is subjected to pressure stabilization through an air pressure reducing valve 31, and then flow regulation is performed through a first electronic control pressure regulating valve 33 and a first throttling orifice plate 34 in sequence, wherein the flow regulation range is 0.041-0.220 kg/s;

4) dividing the normal-temperature high-pressure dry air subjected to flow regulation into two paths; one path of the air flow is regulated at normal temperature through a second electric control pressure regulating valve 41; the other path of the air is subjected to heat exchange through a heat exchanger 52 to generate low-temperature air with the temperature lower than the temperature required by the engine combustion chamber, and then the low-temperature air flow is regulated through a second orifice plate 53;

5) and mixing the normal-temperature air output by the air auxiliary path supply unit 4 and the low-temperature air output by the low-temperature heat exchange unit 5 to obtain air with the temperature required by the test, and sending the air into a combustion chamber of the engine.