A variable temperature gas supply system and method based on liquid working medium

Abstract

The present invention discloses a variable temperature gas supply system and method based on liquid working medium. The system comprises a mobile storage tank (1), the outlet of which is respectively connected to a normal temperature gasifier (2) and a low temperature gasifier (3), and is used to input the liquid working medium in the mobile storage tank (1) into the normal temperature gasifier (2) and the low temperature gasifier (3); the outlet of the normal temperature gasifier (2) is connected to the inlet of a buffer gas reservoir (6) through a normal temperature valve (4), the outlet of the low temperature gasifier (3) is connected to the inlet of the buffer gas reservoir (6) through a low temperature valve (5), the outlet of the buffer gas reservoir (6) is connected to a flow meter (8) through a flow control valve (7), and the outlet of the flow meter (8) is connected to the output port of the variable temperature gas supply system through a gas heater (9). The system can ensure the supply of any combination of gas flow and temperature, and can adapt to diversified gas supply.

Description

Technical Field

[0001] The present invention relates to the field of refrigeration and cryogenic technology, and in particular to a variable-temperature gas supply system and method based on a liquid working medium. Background Art

[0002] In many scientific research and industrial fields, research objects and engineering objects need to be cooled and cryogenically treated, which puts forward many requirements for the required refrigeration and cryogenic environment, such as low vibration and good temperature uniformity. Traditional refrigerators are often large in size, inconvenient to move, and have large vibrations, resulting in poor experimental engineering effects. Direct immersion in saturated cryogenic liquids often has problems such as fixed temperature and mismatched temperature zones.

[0003] In the process of precision equipment integration in large scientific projects, it is often necessary to heat and bake the equipment partially or as a whole. Some of the equipment is intended to restore temperature, while others are intended to remove moisture. These devices often cannot be heated directly, and even cannot be heated by heaters.

[0004] Whether it is to provide a low-temperature environment or to heat and bake the equipment, it is generally not convenient to provide gas working fluids on site, and it is often necessary to constantly replace gas cylinders, which takes up a lot of manpower and financial resources. Summary of the invention

[0005] In view of this, the present invention proposes a specially designed variable temperature gas supply system and supply method based on liquid working fluid, which are used to solve the problems introduced in the above background technology.

[0006] The specific technical solutions are as follows:

[0007] A variable temperature gas supply system based on liquid working fluid, characterized in that it includes a mobile storage tank 1, the outlet of the mobile storage tank 1 is respectively connected to a normal temperature vaporizer 2 and a low temperature vaporizer 3, and is used to input the liquid working fluid in the mobile storage tank 1 into the normal temperature vaporizer 2 and the low temperature vaporizer 3; the outlet of the normal temperature vaporizer 2 is connected to the inlet of a buffer gas reservoir 6 through a normal temperature valve 4, the outlet of the low temperature vaporizer 3 is connected to the inlet of the buffer gas reservoir 6 through a low temperature valve 5, the outlet of the buffer gas reservoir 6 is connected to a flow meter 8 through a flow control valve 7, and the outlet of the flow meter 8 is connected to the output port of the variable temperature gas supply system through a gas heater 9.

[0008] Furthermore, the output port includes a gas quick connector 14, a vacuum quick connector 15 and a knife-edge flange 16; wherein, the outlet of the gas heater 9 is connected to the gas quick connector 14 via a first stop valve 11, the outlet of the gas heater 9 is connected to the vacuum quick connector 15 via a second stop valve 12, and the outlet of the gas heater 9 is connected to the knife-edge flange 16 via a third stop valve 13.

[0009] Furthermore, the outlet of the buffer gas reservoir 6 is connected to the direct gas line interface 18 via the direct gas line valve 17 for directly outputting low-temperature gas or normal-temperature gas.

[0010] Furthermore, the inlet of the buffer gas reservoir 6 is placed at 1 / 4 of the distance from the bottom, and the outlet is arranged at the top.

[0011] Furthermore, the inlet of the gas heater 9 is placed at the bottom, and a temperature sensor 10 is provided at the outlet.

[0012] Furthermore, the inlet of the normal temperature gasifier 2 is located at the bottom, the outlet is located at the top, and a strong flow wind device is arranged outside; the inlet of the low temperature gasifier 3 is located at the bottom, the outlet is located at the top, and a strong flow wind device is arranged outside.

[0013] A variable temperature gas supply method based on liquid working medium, the steps comprising:

[0014] 1) When high-temperature gas is needed, the liquid working medium in the mobile storage tank 1 is input into the normal temperature vaporizer 2; the normal temperature vaporizer 2 automatically heats the input liquid working medium into normal temperature gas and inputs it into the buffer gas reservoir 6, and the buffer gas reservoir 6 inputs the gas into the gas heater 9 to heat it to the set high temperature and then outputs it to the output port;

[0015] 2) When low-temperature gas is needed, the liquid working medium in the mobile storage tank 1 is input into the low-temperature vaporizer 3; the low-temperature vaporizer 3 automatically processes the liquid working medium input from the mobile storage tank 1 into low-temperature gas and inputs it into the buffer gas reservoir 6, and the buffer gas reservoir 6 inputs the gas into the gas heater 9 to heat it to the set low-temperature temperature and then outputs it to the output port.

[0016] Furthermore, the buffer gas reservoir 6 inputs the gas into the gas heater 9 through the flow control valve 7 and the flow meter 8.

[0017] Furthermore, the opening of the flow control valve 7 is automatically adjusted according to the feedback of the flow meter 8. When the flow monitored by the flow meter 8 is less than the set value Q, the opening of the flow control valve 7 is automatically opened wider. When the flow monitored by the flow meter 8 is greater than the set value Q, the opening of the flow control valve 7 is automatically closed.

[0018] Furthermore, the inlet of the gas heater 9 is placed at the bottom, and a temperature sensor 10 is provided at the outlet; when the temperature measured by the temperature sensor 10 is lower than the set value T, the power of the gas heater 9 automatically increases, and when the temperature measured by the temperature sensor 10 is higher than the set value T, the power of the gas heater 9 automatically decreases.

[0019] The variable temperature gas supply system of the present invention comprises a mobile storage tank 1, a normal temperature vaporizer 2, a low temperature vaporizer 3, a normal temperature valve 4, a low temperature valve 5, a buffer gas reservoir 6, a flow control valve 7, a flow meter 8, a gas heater 9, a temperature sensor 10, a first stop valve 11, a second stop valve 12, a third stop valve 13, a gas quick connector 14, a vacuum quick connector 15, a knife-edge flange 16, a direct gas circuit valve 17, a direct gas circuit interface 18, etc. The normal temperature vaporizer 2 can automatically heat the input liquid working medium into normal temperature gas; the low temperature vaporizer 3 can automatically process the input liquid working medium into low temperature gas. The outlet of the mobile storage tank 1 is connected to the normal temperature vaporizer 2 and the low temperature vaporizer 3 at the same time. The outlet of the normal temperature vaporizer 2 is connected to the buffer gas reservoir 6 through the normal temperature valve 4. The outlet of the low temperature vaporizer 3 is connected to the buffer gas reservoir 6 through the low temperature valve 5. The outlet of the buffer gas reservoir 6 is connected to the flow meter 8 through the flow control valve 7. The outlet of the flow meter 8 is connected to the gas heater 9. When high temperature gas is needed, the normal temperature valve 4 is opened, and the liquid working medium in the mobile storage tank 1 enters the normal temperature vaporizer 2, becomes room temperature gas and finally flows through the gas heater 9 and is heated to the set high temperature. When low temperature gas is needed, the low temperature valve 5 is opened, and the liquid working medium enters the low temperature vaporizer 5, becomes low temperature saturated gas, and finally flows through the gas heater 9 and is heated to the set low temperature. The outlet of the gas heater 9 is simultaneously connected to the inlets of the first stop valve 11, the second stop valve 12, and the third stop valve 13, and the inlet of the direct gas path valve 17 is connected to the outlet of the buffer gas reservoir 6.

[0020] In a preferred embodiment of the present invention, the working fluid stored in the mobile storage tank 1 is a liquid working fluid having a boiling point lower than room temperature.

[0021] In a preferred embodiment of the present invention, the inlet of the normal temperature gasifier 2 and the low temperature gasifier 3 are placed at the bottom, the outlet is placed at the top, and a strong air flow is set outside to achieve miniaturization.

[0022] In a preferred embodiment of the present invention, the inlet of the buffer gas reservoir 6 is placed at 1 / 4 of the distance from the bottom, and the outlet is arranged at the top.

[0023] In a preferred embodiment of the present invention, the opening of the flow control valve 7 is not fixed, and is automatically adjusted according to the feedback of the flow meter 8. A closed-loop control is adopted, when the flow meter shows that the flow rate is less than the set value Q, the opening of the flow control valve 7 is automatically opened, and when it is greater than the set value Q, the opening of the flow control valve 7 is automatically closed, and the PID control automatically finds the balance point.

[0024] In a preferred embodiment of the present invention, the inlet of the gas heater 9 is placed at the bottom, and the outlet is provided with a temperature sensor 10. The heating power is not fixed and is automatically adjusted according to temperature feedback. A closed-loop control is adopted. When the temperature measured by the temperature sensor 10 is less than the set value T, the power of the gas heater 9 is automatically increased. When it is greater than the set value T, the power is automatically reduced, and the PID control automatically finds a balance point.

[0025] In a preferred embodiment of the present invention, the structure of the gas heater 9 is a double-stage series connection of heating pipes, which can avoid the uneven distribution of gas flow in parallel and the resulting heating power difference, causing large temperature fluctuations at the rear end.

[0026] In a preferred embodiment of the present invention, the first stop valve 11, the second stop valve 12, and the third stop valve 13 are configured with a variety of interface forms.

[0027] In a preferred embodiment of the present invention, a direct gas circuit valve 17 and a direct gas circuit interface 18 are provided.

[0028] In a preferred embodiment of the present invention, the connecting pipelines starting from the buffer gas reservoir 6, sequentially to the gas quick connector 14, the vacuum quick connector 15, and the knife-edge flange 16, use insulated pipe components.

[0029] Compared with the prior art, the variable temperature gas supply system based on liquid working fluid provided by the present invention has the following advantages:

[0030] First, a low-temperature vaporizer 3 is provided, and a gas heater 9 is used to realize the supply of a specified temperature gas ranging from -200°C to normal temperature (room temperature);

[0031] Second, a normal temperature vaporizer 2 is provided to realize the supply of gas at a specified temperature ranging from normal temperature to high temperature;

[0032] Third, within the design range, ensure the supply of any combination of gas flow and temperature;

[0033] Fourth, the liquid working medium in the mobile storage tank 1 is used as the gas supply source to ensure a large amount of gas supply, compact size and high safety;

[0034] Fifth, the working fluid type is not unique and can be adapted to a variety of gas supplies. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of a variable temperature gas supply system based on liquid working fluid.

[0036] Among them, 1-mobile storage tank, 2-normal temperature vaporizer, 3-low temperature vaporizer, 4-normal temperature valve, 5-low temperature valve, 6-buffer gas reservoir, 7-flow control valve, 8-flow meter, 9-gas heater, 10-temperature sensor, 11-first stop valve, 12-second stop valve, 13-third stop valve, 14-gas quick connector, 15-vacuum quick connector, 16-knife edge flange, 17-direct gas path valve, 18-direct gas path interface.

[0037] Figure 2 Schematic diagram of low-temperature and room-temperature gasifiers.

[0038] Among them, I represents the inlet, O represents the outlet, F represents the fan, H represents the heat exchanger, and T0 represents the outlet thermometer. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the technical solution of the present invention, the embodiments of the present invention will be further described below in conjunction with the accompanying drawings. Obviously, the embodiments in the following drawings are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0040] refer to Figure 1 The present invention provides a variable temperature gas supply system based on liquid working fluid, comprising a mobile storage tank 1, a normal temperature vaporizer 2, a low temperature vaporizer 3, a normal temperature valve 4, a low temperature valve 5, a buffer gas reservoir 6, a flow control valve 7, a flow meter 8, a gas heater 9, a temperature sensor 10, a first stop valve 11, a second stop valve 12, a third stop valve 13, a gas quick connector 14, a vacuum quick connector 15, a knife-edge flange 16, a direct gas path valve 17, a direct gas path interface 18, etc. The outlet of the mobile storage tank 1 is simultaneously connected to the normal temperature vaporizer 2 and the low temperature vaporizer 3, the outlets of the normal temperature vaporizer 2 and the low temperature vaporizer 3 are connected to the buffer gas reservoir 6, the outlet of the buffer gas reservoir 6 is connected to the flow control valve 7, the outlet of the flow meter 8 is connected to the gas heater 9, the outlet of the gas heater 9 is simultaneously connected to the inlets of the first stop valve 11, the second stop valve 12, and the third stop valve 13, and the inlet of the direct gas path valve 17 is connected to the outlet of the buffer gas reservoir 6.

[0041] In this embodiment, the working fluid stored in the mobile storage tank 1 is a liquid working fluid with a boiling point lower than room temperature. The room temperature vaporizer 2 and the low temperature vaporizer 3 are connected in parallel, with the inlets combined at the bottom and the outlets gathered at the top. A suitable strong flow of wind is arranged outside to increase the heat exchange effect and realize the miniaturization of components. The speed of the fan F is controlled by the outlet thermometer T0 (that is, the fan speed is controlled by the outlet temperature monitored by the outlet thermometer as a control signal). When the temperature is close to the saturation temperature of the liquid working fluid, the speed is increased, and when it is higher than a certain value, the speed is reduced.

[0042] In this embodiment, the inlet of the buffer gas reservoir 6 is placed at 1 / 4 of the distance from the bottom, and an outlet is set at the top. The direct gas circuit valve 17 at the outlet of the buffer gas tank 6 has an active pressure relief function to ensure that the pressure of the entire system will not be too high when there is no one on duty. At the same time, a safety valve is set to ensure absolute safety even if the system fails and the power goes out.

[0043] In this embodiment, the opening of the flow control valve 7 is in dynamic change, and is automatically adjusted according to the feedback of the flow meter 8 to ensure the set flow value. The inlet of the gas heater 9 is placed at the bottom, and the temperature sensor 10 is set at the outlet. The heating power is in dynamic change, and is automatically adjusted according to the temperature feedback to ensure the set outlet temperature value. The structure of the gas heater 9 is a two-stage series connection to ensure uniform heating, one for low power and one for standby, and all must be activated when the power increases to a certain value.

[0044] In this embodiment, the first stop valve 11, the second stop valve 12, and the third stop valve 13 are configured with a variety of interface forms, which can meet the various choices of the user. Depending on the specific situation, the connection and sealing method can be selected. The direct gas path valve 17 and the direct gas path interface 18 are set, and low-temperature gas and normal temperature gas can be directly used. Starting from the buffer gas reservoir 6, the subsequent pipelines and components are all insulated to ensure accurate temperature control, while avoiding condensation and frost during low-temperature gas supply and heat loss during high-temperature gas supply.

[0045] In this embodiment, during the use of the variable temperature gas supply system based on liquid working fluid, first, sufficient liquid working fluid is injected into the mobile storage tank, and the entire system is purged or replaced to ensure that pure working medium is sealed from the inlet to the outlet of the entire system. Then, the mobile storage tank is self-pressurized and maintained after reaching a certain equilibrium pressure. According to the target situation, the corresponding vaporizer is selected and the corresponding valve is opened. The target flow value and target temperature are set. After the outlet stop valve is opened, the system can work automatically to ensure stable gas supply.

[0046] In this embodiment, the design of the gas heater 9, the flow control valve 7, the normal temperature gasifier 2, the low temperature gasifier 3, etc. should comprehensively refer to many factors such as pressure, gas supply capacity, temperature, heat exchange, system stability, etc. Specifically, the resistance adjustment coefficient of the flow control valve 7 can be designed according to the pressure and the maximum gas supply capacity. Where δ represents the resistance adjustment coefficient, ΔP represents the pressure difference, ρ represents the density, and u represents the flow rate. The minimum structural parameters of the low-temperature gasifier 3 and the normal-temperature gasifier 2 are designed based on the minimum gas supply capacity. Where Q h Indicates the heat exchange rate, represents mass flow, ΔH represents enthalpy difference, k represents comprehensive heat transfer coefficient, A represents heat exchange area, and ΔT represents temperature difference. According to the maximum air supply capacity, the maximum air supply parameters of low-temperature gasifier 3 and normal temperature gasifier 2 can be designed, h = f (u), where h represents convection heat transfer coefficient, u represents wind speed, and f represents functional relationship. According to the air supply temperature and maximum air supply capacity, the electric power and other parameters of gas heater 9 can be designed and determined. Q d represents electric power, Cp represents specific heat capacity, To represents outlet temperature, and Ti represents inlet temperature.

[0047] The present invention is provided with a low-temperature gasifier 3, which cooperates with a gas heater 9 to realize the supply of a specified temperature gas from about -200°C to room temperature; a normal temperature gasifier 2 is provided to realize the supply of a specified temperature gas from room temperature to high temperature; therefore, the present invention ensures the supply of any combination of gas flow and temperature within the design range.

[0048] The present invention uses the liquid working fluid in the mobile storage tank 1 as the gas supply source, thereby ensuring a relatively large supply of gas, and having a compact volume and a high degree of safety; moreover, the working fluid types are not unique, and the invention can be adapted to a variety of gas supplies.

[0049] The above is only used to illustrate the technical solution of the present invention, and is not intended to limit the invention. Although the above embodiments are described in detail, those skilled in the art can replace, modify and simply change them without departing from the scope of the present technical solution, and these replacements, modifications and simple changes cannot cause the essence of the corresponding technical solution to deviate from the scope of the present use of new embodiments.

Claims

1. A variable temperature gas supply system based on liquid working fluid, characterized in that: The invention comprises a mobile storage tank (1), wherein the outlet of the mobile storage tank (1) is respectively connected to a normal temperature vaporizer (2) and a low temperature vaporizer (3), and is used to input the liquid working medium in the mobile storage tank (1) into the normal temperature vaporizer (2) and the low temperature vaporizer (3); the outlet of the normal temperature vaporizer (2) is connected to the inlet of a buffer gas reservoir (6) through a normal temperature valve (4), the outlet of the low temperature vaporizer (3) is connected to the inlet of the buffer gas reservoir (6) through a low temperature valve (5), the outlet of the buffer gas reservoir (6) is connected to a flow meter (8) through a flow control valve (7), and the outlet of the flow meter (8) is connected to the output port of a variable temperature gas supply system through a gas heater (9); wherein: The resistance adjustment coefficient of the flow control valve (7) ΔP represents the pressure difference, ρ represents the density, and u represents the flow rate; Based on heat exchange Determining the minimum structural parameters of the low-temperature gasifier (3) and the normal-temperature gasifier (2), represents mass flow rate, ΔH represents enthalpy difference, k represents comprehensive heat transfer coefficient, A represents heat exchange area, and ΔT represents temperature difference; The electric power of the gas heater (9) Cp represents specific heat capacity, To represents outlet temperature, and Ti represents inlet temperature.

2. The variable temperature gas supply system based on liquid working medium according to claim 1, characterized in that: The output port comprises a gas quick connector (14), a vacuum quick connector (15) and a knife-edge flange (16); wherein the outlet of the gas heater (9) is connected to the gas quick connector (14) via a first stop valve (11), the outlet of the gas heater (9) is connected to the vacuum quick connector (15) via a second stop valve (12), and the outlet of the gas heater (9) is connected to the knife-edge flange (16) via a third stop valve (13).

3. The variable temperature gas supply system based on liquid working medium according to claim 1 or 2, characterized in that: The outlet of the buffer gas reservoir (6) is connected to the direct gas line interface (18) via a direct gas line valve (17) for directly outputting low-temperature gas or normal-temperature gas.

4. The variable temperature gas supply system based on liquid working medium according to claim 1, characterized in that: The inlet of the buffer gas reservoir (6) is located at 1 / 4 of the distance from the bottom, and the outlet is arranged at the top.

5. The variable temperature gas supply system based on liquid working medium according to claim 1, characterized in that: The inlet of the gas heater (9) is placed at the bottom, and a temperature sensor (10) is provided at the outlet.

6. The variable temperature gas supply system based on liquid working medium according to claim 1, characterized in that: The inlet of the normal temperature gasifier (2) is located at the bottom, the outlet is located at the top, and a strong flow wind device is arranged outside; the inlet of the low temperature gasifier (3) is located at the bottom, the outlet is located at the top, and a strong flow wind device is arranged outside.

7. A variable temperature gas supply method based on liquid working medium, the steps comprising: 1) When high-temperature gas is needed, the liquid working medium in the mobile storage tank (1) is input into the normal-temperature gasifier (2); the normal-temperature gasifier (2) automatically heats the input liquid working medium into normal-temperature gas and inputs it into the buffer gas reservoir (6); the buffer gas reservoir (6) inputs the gas into the gas heater (9) through the flow control valve (7) and the flow meter (8) to heat the gas to a set high-temperature temperature and then outputs it to the output port; 2) When cryogenic gas is needed, the liquid working medium in the mobile storage tank (1) is input into the cryogenic gasifier (3); the cryogenic gasifier (3) automatically processes the liquid working medium input from the mobile storage tank (1) into cryogenic gas and inputs the cryogenic gas into the buffer gas reservoir (6); the buffer gas reservoir (6) inputs the gas into the gas heater (9) through the flow control valve (7) and the flow meter (8) to heat the gas to a set cryogenic temperature and then outputs the gas to the output port; The resistance adjustment coefficient of the flow control valve (7) is ΔP represents the pressure difference, ρ represents the density, and u represents the flow rate; based on the heat transfer Determining the minimum structural parameters of the low-temperature gasifier (3) and the normal-temperature gasifier (2), represents mass flow, ΔH represents enthalpy difference, k represents comprehensive heat transfer coefficient, A represents heat exchange area, ΔT represents temperature difference; the electric power of the gas heater (9) Cp represents specific heat capacity, To represents outlet temperature, and Ti represents inlet temperature.

8. The method according to claim 7, characterized in that The opening of the flow control valve (7) is automatically adjusted according to the feedback of the flow meter (8). When the flow rate monitored by the flow meter (8) is less than the set value Q, the opening of the flow control valve (7) is automatically increased. When the flow rate monitored by the flow meter (8) is greater than the set value Q, the opening of the flow control valve (7) is automatically decreased.

9. The method according to claim 7, characterized in that The inlet of the gas heater (9) is arranged at the bottom, and a temperature sensor (10) is arranged at the outlet; when the temperature measured by the temperature sensor (10) is lower than a set value T, the power of the gas heater (9) is automatically increased, and when the temperature measured by the temperature sensor (10) is higher than the set value T, the power of the gas heater (9) is automatically decreased.

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