Controllable temperature and pressure experimental method and device for dynamic dissolution and precipitation characteristics of wide-temperature-range multi-fluid mixtures

Abstract

The present application relates to a kind of wide temperature range multiple fluid mixture dynamic dissolution precipitation characteristic controllable temperature pressure experimental method and device, belong to multiphase flow and fluid mixture dynamic dissolution precipitation characteristic research field.Solve the existing dissolution precipitation experimental method difficult to be applicable to multiple fluid mixture system, experimental condition coverage range is limited, and in dynamic condition, it is difficult to accurately control the problem that temperature and pressure are mutually independent.The device includes fluid motion loop, temperature control loop and cooling liquid circulation loop, the accurate control of experimental system pressure is realized by the pressure regulating tank of adjustable volume, the stable regulation of experimental system in wide temperature range is realized by temperature control loop, and the dissolution, precipitation and phase change process of multiple fluid mixtures under dynamic conditions are monitored and characterized in real time by a variety of sensors.The present application can simulate the running process of actual engineering system under dynamic conditions, and realize the controllable reproduction of fluid mixture dissolution precipitation behavior.

Description

Technical Field

[0001] This invention belongs to the field of research on the dynamic dissolution and precipitation characteristics of multiphase flow and fluid mixtures, and specifically relates to an experimental method and apparatus for characterizing the dynamic dissolution and precipitation behavior of various fluid mixtures under controllable temperature and pressure conditions. Background Technology

[0002] Dissolution and precipitation phenomena are prevalent in engineering systems involving the synergistic effects of multiphase working fluids. The solubility and phase evolution of various fluids are typically highly sensitive to temperature and pressure conditions. When the system's operating state changes, the dynamic dissolution and precipitation behavior of solutes in the fluid mixture significantly affects the mass transfer process and overall operational stability. Therefore, experimental research on the dynamic dissolution and precipitation characteristics of fluid mixtures under variable temperature and pressure conditions is of great significance for revealing the relevant physical mechanisms. This phenomenon is particularly typical in refrigeration and air conditioning systems. Refrigerant and lubricating oil, as two working fluids that coexist and interact for a long time in the system, are always in contact inside the compressor. The refrigerant achieves its refrigeration function through circulation within the system, while the lubricating oil is mainly used to lubricate and cool the moving parts inside the compressor to reduce friction loss, mechanical wear, and ensure the normal operation of the equipment. However, in actual operation, dissolution and precipitation inevitably occur between the refrigerant and lubricating oil. Their solubility changes significantly with temperature and pressure conditions, resulting in a complex multiphase mass transfer process inside the compressor, which has a significant impact on the stability and reliability of the system operation.

[0003] Under normal operating temperatures, the solubility of refrigerant in lubricating oil is relatively low, and the changes in the physical properties of lubricating oil are limited, allowing the compressor to maintain a relatively stable lubrication state. However, under low-temperature shutdown or low-temperature start-up conditions, the solubility of refrigerant in lubricating oil increases significantly, and a large amount of refrigerant may dissolve in the lubricating oil, forming a mixed solution with a high refrigerant content. When the system starts up or operating conditions change abruptly, with rapid changes in temperature and pressure, the refrigerant dissolved in the lubricating oil will quickly precipitate and undergo phase changes, causing a large amount of lubricating oil to be carried into the system circulation. This can lead to insufficient lubricating oil supply inside the compressor, or even oil-free operation. This process easily causes moving parts to be in a dry film or semi-dry film lubrication state, exacerbating mechanical wear and significantly reducing the compressor's service life and operational reliability. Therefore, to accurately reveal the dynamic dissolution and precipitation behavior of refrigerant in lubricating oil under different temperature and pressure conditions, it is necessary to conduct dynamic dissolution experiments that can simulate the actual operation of the refrigeration system and achieve independent and precise control of temperature and pressure. However, existing dissolution experiments are mostly based on natural equilibrium processes, and the experimental subjects are usually limited to single or specific working fluid systems, making them difficult to apply to dynamic dissolution studies of various fluid mixtures. At the same time, their experimental operating conditions have limited coverage, making it difficult to achieve stable operation under wide temperature range conditions. Furthermore, under dissolution equilibrium conditions, it is usually impossible to independently and precisely control the system temperature and pressure, thus making it difficult to realistically simulate the actual operating state of refrigeration systems under low-temperature start-up and sudden changes in operating conditions. Therefore, a new experimental method and device are urgently needed to solve this problem. Summary of the Invention

[0004] In view of this, to address the problems of existing dissolution and precipitation experimental methods being difficult to apply to various fluid mixture systems, having limited experimental condition coverage, and being unable to independently and precisely control temperature and pressure under dynamic conditions, thus making it difficult to realistically simulate the dissolution and precipitation behavior of fluid mixtures under low-temperature start-up and sudden change conditions, a new experimental method and apparatus are proposed for studying the dynamic dissolution and precipitation characteristics of various fluid mixtures over a wide temperature range and achieving controllable temperature and pressure. This method and apparatus can simulate the operation of actual engineering systems under dynamic conditions, achieving independent and precise control of the temperature and pressure of the experimental system, thereby stably and controllably reproducing the dissolution and precipitation process of various fluid mixtures under different operating conditions.

[0005] To achieve the above objectives, the present invention employs the following technical solution: a controllable temperature and pressure experimental method for the dynamic dissolution and precipitation characteristics of a multi-fluid mixture over a wide temperature range. This method involves introducing at least two mutually soluble or precipitable fluids into a closed experimental system to form a fluid mixture. Through an independent temperature control loop, the temperature of the experimental system is continuously or progressively controlled over a wide temperature range covering the entire dissolution and precipitation process of the fluid mixture. The pressure of the experimental system is independently, continuously, or stepwise controlled through a pressure control unit based on an adjustable system volume. Under non-thermodynamic equilibrium conditions, the fluid mixture undergoes a dynamic dissolution and precipitation process. During this dynamic process, the temperature, pressure, and at least one physical property parameter of the experimental system are monitored in real time, thereby obtaining the dynamic dissolution and precipitation characteristics of the fluid mixture under wide temperature range and controllable temperature and pressure conditions.

[0006] Preferably, the wide temperature range covers the temperature range in which the fluid mixture transitions from a low-temperature, high-solubility state to a high-temperature, low-solubility state, or from a high-solubility state to a precipitation state, and the temperature range is adaptively set according to the type of fluid being measured.

[0007] Preferably, the pressure regulation is achieved by changing the effective volume of the closed experimental system, so that the pressure of the experimental system remains stable, changes slowly or changes rapidly during the dissolution or precipitation process.

[0008] Preferably, the dynamic dissolution process is carried out under conditions of continuous or sudden changes in temperature and pressure to simulate the start-up, shutdown, or sudden changes in operating conditions of an actual engineering system.

[0009] Preferably, the physical property parameters include at least one or more of the following: viscosity of the fluid mixture, phase change characteristics, or optical response signal.

[0010] Preferably, the fluid mixture is a refrigerant and lubricating oil system.

[0011] An apparatus for an experimental method of dynamically dissolving and releasing multi-fluid mixtures over a wide temperature range with controllable temperature and pressure includes three flow loops: a fluid motion loop for introducing, transporting, and mixing the experimental fluids; a temperature control loop for independently regulating the temperature of the experimental system over a wide temperature range; and a coolant circulation loop for recycling the coolant during system installation and cleaning.

[0012] Preferably, the fluid motion circuit includes a vacuum pumping unit, a pressure control unit, a fluid storage unit, a buffer unit, and a balance chamber unit, used to construct a controllable closed experimental environment; the temperature control circuit includes a first water tank, a chiller unit, a chilled water outlet pipe, and a chilled water return pipe, with the first water tank connected to the chiller unit via the chilled water outlet pipe and the chilled water return pipe; the coolant circulation circuit includes a second water tank, a drain pipe, an inlet pipe, an inlet water pump, and an overflow pipe, with the first water tank connected to the second water tank via the drain pipe and the overflow pipe; the inlet water pump is connected to the first water tank via the inlet pipe.

[0013] Preferably, the vacuum pumping unit includes a vacuum pump, a refrigerant tank, a vacuum pump control valve, a refrigerant tank control valve, and a refrigerant control valve, wherein the vacuum pump is connected to the vacuum pump control valve; and the refrigerant tank is connected to the refrigerant control valve via the refrigerant tank control valve. The buffer unit includes a buffer tank control valve, a buffer tank pressure sensor, a buffer tank balance vessel connecting valve, and a buffer tank. The buffer tank is connected to the buffer tank control valve, the buffer tank pressure sensor, and the buffer tank balance vessel connecting valve. The balancing chamber unit includes a balancing vessel control valve, a slow-release tank balancing vessel connecting valve, a balancing vessel pressure sensor, a balancing vessel pressure regulating tank connecting valve, and a balancing vessel. The balancing vessel is connected to the balancing chamber unit, which includes the balancing vessel control valve, the slow-release tank balancing vessel connecting valve, the balancing vessel pressure sensor, and the balancing vessel pressure regulating tank connecting valve. The balancing vessel is placed inside the No. 1 water tank. The pressure control unit achieves precise pressure control by adjusting the effective volume of the experimental system.

[0014] Preferably, the equilibrium vessel is equipped with a pressure sensor, a temperature sensor, a property sensor, and a visualization observation window for multi-parameter characterization of the dynamic dissolution and release process of the fluid mixture.

[0015] Preferably, the pressure control unit includes an adjustable-volume pressure regulating tank, and the pressure of the experimental system can be continuously and controllably adjusted by adjusting the position of the piston inside the pressure regulating tank. The pressure regulating tank is connected to the pressure regulating tank control valve and the pressure regulating tank pressure sensor. The vacuum pump control valve, refrigerant control valve, pressure regulating tank control valve, balance vessel control valve, and slow-release tank control valve converge at the same position.

[0016] Preferably, the device further includes a sensing and data acquisition unit for acquiring experimental parameters in real time.

[0017] Compared with existing technologies, the beneficial effects of the experimental method and apparatus for controlling the temperature and pressure of dynamic dissolution and release characteristics of a wide-temperature-range multi-fluid mixture described in this invention are: 1. This invention achieves controllable adjustment and stable reproduction of the dissolution and precipitation process of various fluid mixtures under dynamic conditions by introducing an independently adjustable temperature control loop and a pressure control structure based on volume adjustment.

[0018] 2. Compared with traditional dissolution and precipitation experimental methods that usually rely on natural equilibrium processes, are difficult to apply to various fluid systems, and are difficult to independently and precisely control temperature and pressure simultaneously under equilibrium or non-equilibrium conditions, this invention can actively regulate the dissolution and precipitation behavior of fluid mixtures under non-equilibrium conditions, thereby improving the repeatability of the experimental process and the simulability of the operating conditions.

[0019] 3. Through the method and apparatus of this invention, the dissolution process of various fluid mixtures under wide temperature range conditions, as well as the rapid precipitation process occurring during startup or sudden changes in operating conditions, can be stably captured and quantitatively characterized. The fluid transport characteristics, changes in physical properties, and phase evolution behavior during the dissolution and precipitation process can be monitored in real time, effectively overcoming the problems of uncontrollable dissolution and precipitation processes and difficulty in observing transient characteristics in traditional experiments. This provides a reliable experimental basis for studying the mass transfer and phase transition mechanisms of multiphase systems under varying operating conditions.

[0020] 4. In summary, this invention constructs a dynamic dissolution and precipitation experimental method and device that integrates wide-range temperature control, controllable pressure regulation, and real-time monitoring of multiple parameters. It realizes the controllable reproduction and systematic characterization of the dissolution and precipitation behavior of various fluid mixtures under complex working conditions, and can provide a stable and scalable experimental research means for the structural design optimization, operation control strategy formulation, and key component reliability research of related engineering systems. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the integrated temperature and pressure experimental device for controlling the dynamic dissolution and release characteristics of a wide-temperature-range mixture of multiple fluids as described in this invention. Figure 2 This is a schematic diagram of the structure of the gas-releasing tank described in this invention; Figure 3 This is a schematic diagram of the structure of the balance vessel described in this invention; Figure 4 This is a schematic diagram of the pressure regulating tank described in this invention; Figure 5 This is a diagram showing the executable experimental process and key operation steps of the integrated experimental device described in this invention; In the diagram: 1-Vacuum pump, 2-Refrigerant tank, 3-Vacuum pump control valve, 4-Refrigerant tank control valve, 5-Refrigerant control valve, 6-Pressure regulator tank control valve, 7-Balancing vessel control valve, 8-Residual gas tank control valve, 9-Residual gas tank pressure sensor, 10-Residual gas tank / Balancing vessel connecting valve, 11-Balancing vessel pressure sensor, 12-Balancing vessel / Pressure regulator tank connecting valve, 13-Residual gas tank, 14-Balancing vessel, 15-Pressure regulator tank, 16-Water tank No. 1, 17-Water tank No. 2, 18-Drain connecting pipe, 19-Water supply connecting pipe. 20-Water pump for water supply, 21-Magnetic stirrer, 22-Chiller unit, 23-Cold water outlet pipe, 24-Cold water return pipe, 25-Overflow pipe, 26-Pressure sensor for pressure regulating tank, 131-Temperature sensor for venting tank, 141-Temperature sensor on top of balance vessel, 142-Viscosity / fiber optic sensor No. 1, 143-Viscosity / fiber optic sensor No. 2, 144-Temperature sensor on bottom of balance vessel, 145-Glass window, 151-Threaded piston, 152-Graduation line, 153-Pressure regulating tank cavity. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the drawings, and not all of them. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the invention.

[0023] For a detailed implementation method one, please refer to... Figure 1 This embodiment describes a comprehensive temperature and pressure-controlled experimental apparatus for studying the dynamic dissolution and precipitation characteristics of multi-fluid mixtures over a wide temperature range. The apparatus comprises three independent but collaborative flow loops: a fluid motion loop, a temperature control loop, and a coolant circulation loop. It is used to study the dynamic dissolution and precipitation behavior of multi-fluid mixtures under controlled temperature and pressure conditions. The fluid motion loop is used for the introduction, transport, and mixing of the experimental fluids; the temperature control loop is used for independent temperature regulation of the experimental system over a wide temperature range; and the coolant circulation loop is used for the recycling of the cooling medium during system installation and cleaning. The apparatus also includes a sensing and data acquisition unit for real-time acquisition of experimental parameters.

[0024] The fluid motion circuit includes a vacuum pumping unit, a fluid storage unit, a pressure control unit, a buffer unit, and a balance chamber unit, which are used to construct a controllable closed experimental environment. The vacuum pumping unit includes a vacuum pump 1, a refrigerant tank 2, a vacuum pump control valve 3, a refrigerant tank control valve 4, and a refrigerant control valve 5. The vacuum pump 1 is connected to the vacuum pump control valve 3; the refrigerant tank 2 is connected to the refrigerant control valve 5 through the refrigerant tank control valve 4. The buffer unit includes a gas retarder control valve 8, a gas retarder pressure sensor 9, a gas retarder balance vessel connecting valve 10, and a gas retarder 13. The gas retarder 13 is connected to the gas retarder control valve 8, the gas retarder pressure sensor 9, and the gas retarder balance vessel connecting valve 10. The balance chamber unit includes a balance vessel control valve 7, a slow-release tank balance vessel connecting valve 10, a balance vessel pressure sensor 11, a balance vessel pressure regulating tank connecting valve 12, and a balance vessel 14. The balance vessel 14 is connected to the balance chamber unit, which includes the balance vessel control valve 7, the slow-release tank balance vessel connecting valve 10, the balance vessel pressure sensor 11, and the balance vessel pressure regulating tank connecting valve 12. Vacuum pump control valve 3, refrigerant control valve 5, pressure regulating tank control valve 6 in the pressure control unit, balance tank control valve 7, and slow-release tank control valve 8 converge at the same location.

[0025] The equilibrium vessel 14 is equipped with pressure sensors, temperature sensors, property sensors, and a visualization observation window for multi-parameter characterization of the dynamic dissolution and release process of the fluid mixture. The fluid motion loop is used to construct a closed and controllable experimental system, enabling the introduction, transport, mixing, and dynamic dissolution and release of the experimental fluid. Through valve combination control, the flow and connection of fluid between the simmering tank, equilibrium vessel, and pressure regulating tank can be selectively achieved, thereby meeting the requirements of different experimental conditions.

[0026] Specifically, the balance vessel 14 is equipped with multiple functional measurement interfaces, including a balance vessel pressure sensor 11 for measuring the pressure of the gaseous fluid inside the balance vessel, a balance vessel upper temperature sensor 141 for measuring the temperature of the gaseous refrigerant, a first viscosity / fiber optic sensor 142 and a second viscosity / fiber optic sensor 143 for measuring the viscosity of the fluid mixture, a balance vessel lower temperature sensor 144 for measuring the temperature of the fluid mixture, and a glass window 145 for observing the dynamic dissolution and desorption process of the fluid mixture. The viscosity parameters can be obtained either directly by measuring with a viscometer or by inversion calculation based on the optical response signal of the fluid mixture. These two methods are cross-checked to improve the reliability of the measurement results.

[0027] At the position corresponding to the balance vessel 14, a magnetic stirring device 21 is installed on the outside of the first water tank 16 to drive the movement of the magnetic stir bar inside the balance vessel, so as to regulate the dissolution and precipitation rate of the refrigerant and lubricating oil.

[0028] The refrigerant tank 13 is equipped with a refrigerant tank temperature sensor 131 and a refrigerant tank pressure sensor 9, which are used to measure the temperature and pressure of the refrigerant entering the refrigerant tank, thereby characterizing the state of the refrigerant tank.

[0029] Precise pressure control of the experimental system is achieved through volume adjustment of the pressure regulating tank 15 in the pressure control unit, thereby realizing independent and controllable regulation of temperature and pressure. The pressure regulation unit includes a pressure regulating tank control valve 6, a pressure regulating tank 15, and a pressure regulating tank pressure sensor 26. The pressure regulating tank 15 includes a threaded piston 151, scale lines 152, and a pressure regulating tank cavity 153. The threaded piston 151 is fitted inside the pressure regulating tank cavity 153, and the scale lines 152 are provided on the threaded piston 151. The pressure regulating tank pressure sensor 26 is installed on the pressure regulating tank cavity 153. By driving the threaded piston 151 axially through a reducer, the effective volume of the pressure regulating tank cavity 153 can be precisely adjusted, thereby achieving active and continuous pressure regulation of the experimental system without relying on natural equilibrium. During the experiment, by opening the balance vessel pressure regulating tank connecting valve 12, the balance vessel and the pressure regulating tank are connected, and the volume of the pressure regulating tank can be adjusted to achieve precise control of the dissolution and desorption pressure conditions of the fluid mixture in the balance vessel.

[0030] The temperature control loop enables precise temperature control of the experimental system. The loop includes a primary water tank 16, a chiller unit 22, a chilled water outlet pipe 23, and a chilled water return pipe 24. The primary water tank 16 is connected to the chiller unit 22 via the chilled water outlet pipe 23 and the chilled water return pipe 24. Coolant is contained within the primary water tank 16, and the coolant forms a closed-loop circulation under the action of the chiller unit, providing stable and uniform thermal boundary conditions for the experimental apparatus placed within the primary water tank 16. By adjusting the operating parameters of the chiller unit, continuous or staged precise temperature control of the experimental system can be achieved over a wide temperature range covering the entire process of dissolution and precipitation of the fluid mixture, thereby meeting the experimental requirements of different fluid systems under different thermodynamic states.

[0031] The coolant circulation loop includes a second water tank 17, a drain pipe 18, an inlet pipe 19, an inlet water pump 20, and an overflow pipe 25. A first water tank 16 is connected to the second water tank 17 via the drain pipe 18 and the overflow pipe 25; the inlet water pump 20 is connected to the first water tank 16 via the inlet pipe 19. This loop is mainly used for the transfer and recovery of coolant during the installation, disassembly, and cleaning of the experimental system, thereby improving the convenience and safety of system maintenance.

[0032] The cooperative connection relationship of the three loops is as follows: (1) Coordinated connection between fluid motion loop and temperature control loop: The balance vessel 14 is placed inside the No. 1 water tank 16, which is filled with coolant. The temperature of the fluid mixture in the balance vessel 14 is regulated by the cooling capacity provided by the chiller unit 22. The No. 1 water tank 16 forms a closed-loop coolant circulation with the chiller unit 22 through the chilled water outlet pipe 23 and the chilled water return pipe 24, thereby transferring the cooling capacity of the temperature control loop to the balance vessel 14 in the fluid motion loop, realizing independent and precise temperature control of the fluid motion process.

[0033] (2) Cooperative connection between the fluid motion loop and the coolant circulation loop: The coolant circulation loop transfers the coolant in the No. 1 water tank 16 to the No. 2 water tank 17 through the drain pipe 18, and pumps the coolant back from the No. 2 water tank 17 to the No. 1 water tank 16 through the water inlet pump 20 and the water inlet pipe 19, realizing the circulation, renewal and recovery of the coolant. The overflow pipe 25 is used to maintain a stable coolant level in the No. 1 water tank 16. This loop is responsible for draining and filling the coolant during system installation, disassembly and cleaning, and shares the No. 1 water tank 16 as the connection interface with the fluid motion loop.

[0034] (3) Cooperative connection between temperature control loop and coolant circulation loop: The No. 1 water tank 16 in the temperature control loop is also the storage container for the coolant circulation loop. The coolant serves as the heat transfer medium in the temperature control loop and as the circulating fluid in the coolant circulation loop. The two loops are physically coupled through the No. 1 water tank 16. The coolant circulation loop is responsible for the replenishment and replacement of coolant, while the temperature control loop is responsible for the cooling and circulation temperature control of coolant. The two work together to ensure the stability and uniformity of the temperature of the experimental system.

[0035] This invention also includes an experimental method for controlling the temperature and pressure of dynamic dissolution and precipitation characteristics of a multi-fluid mixture over a wide temperature range. At least two mutually soluble or precipitable fluids are introduced into a closed experimental system to form a fluid mixture. The temperature of the experimental system is continuously or progressively controlled over a wide temperature range covering the entire dissolution and precipitation process of the fluid mixture using an independent temperature control loop. The pressure of the experimental system is independently, continuously, or progressively controlled using a pressure control unit based on the system volume. Under non-thermodynamic equilibrium conditions, the fluid mixture undergoes a dynamic dissolution and precipitation process. During this dynamic process, the temperature, pressure, and at least one physical property parameter of the experimental system are monitored in real time, thereby obtaining the dynamic dissolution and precipitation characteristics of the fluid mixture under wide temperature range and controllable temperature and pressure conditions.

[0036] The wide temperature range refers to the temperature range in which the fluid mixture transitions from a low-temperature, high-solubility state to a high-temperature, low-solubility state, or from a high-solubility state to a precipitation state. The temperature range is adaptively set according to the type of fluid being measured.

[0037] The pressure regulation is achieved by changing the effective volume of the closed experimental system, so that the pressure of the experimental system remains stable, changes slowly or changes rapidly during the dissolution or precipitation process.

[0038] The dynamic dissolution process is carried out under conditions of continuous or sudden changes in temperature and pressure to simulate the startup, shutdown, or sudden changes in operating conditions of actual engineering systems.

[0039] The physical properties include at least one or more of the following: viscosity of the fluid mixture, phase change characteristics, or optical response signal.

[0040] The fluid mixture is a refrigerant and lubricating oil system.

[0041] Example 1 (using R410A-lubricating oil system as an example) The following embodiments are only used to illustrate the technical solutions of the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0042] In this embodiment, R410A refrigerant and a certain type of compressor lubricating oil are selected as the research objects to study their gas-liquid dissolution process (e.g., Figure 5 (Gas-Liquid Dissolution Steps). First, add coolant to water tank 1 and transfer it to water tank 2 through the drain pipe. After adding a predetermined amount of lubricating oil to the balance vessel, install the balance vessel into water tank 1 and seal it. Then, start the water pump to return the coolant to water tank 1. Set the chiller temperature to allow the experimental system temperature to be adjusted within the range of -40℃ to 40℃, and start the circulation to stabilize the experimental environment temperature. Sequentially open the vacuum pump control valve, pressure regulating tank control valve, balance vessel control valve, and venting tank control valve to evacuate the system until the pressure sensors show a pressure close to -0.1MPa. Then, close the relevant valves. Open the refrigerant tank control valve and refrigerant control valve to charge R410A refrigerant into the venting tank. After the temperature and pressure stabilize, open the venting tank balance vessel connection valve and the balance vessel pressure regulating tank connection valve to allow the refrigerant to enter the balance vessel. By adjusting the position of the threaded piston in the pressure regulating tank, the pressure of the experimental system was varied within the range of -0.1 MPa to 3 MPa, thereby controlling the dissolution and precipitation process of the refrigerant in the lubricating oil. During the experiment, temperature, pressure, and property sensors on the equilibrium vessel were used to collect parameter changes in real time to characterize the dynamic dissolution and precipitation characteristics of the R410A-lubricating oil system under wide temperature range and controllable pressure conditions.

[0043] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. An experimental method for dynamically dissolving and releasing multi-fluid mixtures over a wide temperature range with controllable temperature and pressure, characterized in that: At least two mutually soluble or precipitable fluids are introduced into a closed experimental system to form a fluid mixture. The temperature of the experimental system is continuously or in stages controlled within a wide temperature range covering the entire process of dissolution and precipitation of the fluid mixture through an independent temperature control loop. The pressure of the experimental system is independently, continuously, or stepwise controlled through a pressure control unit based on the adjustable system volume. Under non-thermodynamic equilibrium conditions, the fluid mixture undergoes a dynamic dissolution and precipitation process. During the dynamic process, the temperature, pressure, and at least one physical property parameter of the experimental system are monitored in real time to obtain the dynamic dissolution and precipitation characteristics of the fluid mixture under wide temperature range and controllable temperature and pressure conditions.

2. The experimental method for controlling the temperature and pressure of dynamic dissolution and release characteristics of a wide-temperature-range mixture of multiple fluids according to claim 1, characterized in that: The wide temperature range refers to the temperature range in which the fluid mixture transitions from a low-temperature, high-solubility state to a high-temperature, low-solubility state, or from a high-solubility state to a precipitation state. The temperature range is adaptively set according to the type of fluid being measured.

3. The experimental method for controlling the temperature and pressure of dynamic dissolution and release characteristics of a wide-temperature-range mixture of multiple fluids according to claim 1, characterized in that: The pressure regulation is achieved by changing the effective volume of the closed experimental system, so that the pressure of the experimental system remains stable, changes slowly or changes rapidly during the dissolution or precipitation process.

4. The experimental method for controlling the temperature and pressure of dynamic dissolution and release characteristics of a wide-temperature-range mixture of multiple fluids according to claim 1, characterized in that: The dynamic dissolution process is carried out under conditions of continuous or sudden changes in temperature and pressure to simulate the startup, shutdown, or sudden changes in operating conditions of actual engineering systems.

5. The experimental method for controlling the temperature and pressure of dynamic dissolution and release characteristics of a wide-temperature-range mixture of multiple fluids according to claim 1, characterized in that: The physical properties include at least one or more of the following: viscosity of the fluid mixture, phase change characteristics, or optical response signal.

6. An apparatus for an experimental method of dynamically dissolving and releasing multi-fluid mixtures over a wide temperature range with controllable temperature and pressure, as described in any one of claims 1-5, characterized in that: It includes three flow loops: a fluid motion loop for introducing, transporting, and mixing experimental fluids; and a temperature control loop for independently regulating the temperature of the experimental system over a wide temperature range. The coolant circulation loop is used for the recycling of the cooling medium during system installation and cleaning.

7. The apparatus according to claim 6, characterized in that: The fluid motion circuit includes a vacuum pumping unit, a pressure control unit, a fluid storage unit, a buffer unit, and a balance chamber unit, which are used to construct a controllable closed experimental environment; the temperature control circuit includes a No. 1 water tank (16), a chiller unit (22), a chilled water outlet pipe (23), and a chilled water return pipe (24). The No. 1 water tank (16) is connected to the chiller unit (22) through the chilled water outlet pipe (23) and the chilled water return pipe (24); the coolant circulation circuit includes a No. 2 water tank (17), a drain pipe (18), an inlet pipe (19), an inlet water pump (20), and an overflow pipe (25). The No. 1 water tank (16) is connected to the No. 2 water tank (17) through the drain pipe (18) and the overflow pipe (25). The inlet water pump (20) is connected to the No. 1 water tank (16) through the inlet water outlet pipe (19).

8. The apparatus according to claim 7, characterized in that: The vacuum pumping unit includes a vacuum pump (1), a refrigerant tank (2), a vacuum pump control valve (3), a refrigerant tank control valve (4), and a refrigerant control valve (5). The vacuum pump (1) is connected to the vacuum pump control valve (3); the refrigerant tank (2) is connected to the refrigerant control valve (5) through the refrigerant tank control valve (4). The buffer unit includes a gas simmer control valve (8), a gas simmer pressure sensor (9), a gas simmer balance vessel connecting valve (10), and a gas simmer (13). The gas simmer (13) is connected to the gas simmer control valve (8), the gas simmer pressure sensor (9), and the gas simmer balance vessel connecting valve (10). The balance chamber unit includes a balance vessel control valve (7), a slow-release tank balance vessel connecting valve (10), a balance vessel pressure sensor (11), a balance vessel pressure regulating tank connecting valve (12), and a balance vessel (14). The balance vessel (14) is connected to the balance chamber unit, including the balance vessel control valve (7), the slow-release tank balance vessel connecting valve (10), the balance vessel pressure sensor (11), and the balance vessel pressure regulating tank connecting valve (12). The balance vessel (14) is placed inside the No. 1 water tank (16). The pressure control unit achieves precise pressure control by adjusting the effective volume of the experimental system.

9. The apparatus according to claim 8, characterized in that: The balance vessel (14) is equipped with a pressure sensor, a temperature sensor, a physical property sensor and a visualization observation window, which are used to characterize the dynamic dissolution and leaching process of the fluid mixture using multiple parameters.

10. The apparatus according to claim 8, characterized in that: The pressure control unit includes an adjustable pressure regulating tank (15). The pressure of the experimental system can be continuously and controllably adjusted by adjusting the position of the piston inside the pressure regulating tank (15). The pressure regulating tank (15) is connected to the pressure regulating tank control valve (6) and the pressure regulating tank pressure sensor (26). The vacuum pump control valve (3), the refrigerant control valve (5), the pressure regulating tank control valve (6), the balance vessel control valve (7), and the slow gas tank control valve (8) converge at the same position.

Images