An integrated liquid storage buffer and throttling ultra-low temperature water vapor trapping pump device

Abstract

The application relates to the field of vacuum obtaining devices, and discloses an ultra-low-temperature water vapor trapping pump device integrating liquid storage and throttling, which comprises a compressor, an oil separator, a water condenser, a drying filter, a regenerator, multiple heat exchangers and a cold trap. The device further comprises at least one throttling module and a liquid storage module. One end of each throttling module is connected with a gas outlet of one of the heat exchangers, and the other end is connected with a heat exchange interface of the heat exchanger or the rest of the heat exchangers. The throttling module is used for separating and purifying high-pressure liquid refrigerant delivered by a main liquid path, and controllably adjusting flow circulation to match the load demand of the main liquid path in real time. The liquid outlet of the liquid storage module is connected with the main liquid path before or after the regenerator, the liquid inlet is connected with the downstream of the water condenser or the drying filter, and the liquid storage module is used for recoverably supplying liquid refrigerant to the main liquid path.

Description

Technical Field

[0001] This invention relates to the technical field of vacuum acquisition equipment, and in particular to an ultra-low temperature water vapor capture pump device that integrates liquid storage buffer and throttling. Background Technology

[0002] The cryogenic water vapor capture pump is the core equipment in a high vacuum system for capturing water vapor and maintaining the system vacuum. It achieves the physical adsorption of water vapor molecules by using a refrigeration cycle to bring the surface of the cold trap to an ultra-low temperature. The energy efficiency, dynamic response speed, and operational stability of the refrigeration system directly determine the water vapor capture efficiency, temperature control accuracy, and service life of the capture pump.

[0003] Existing cryogenic water vapor capture pump refrigeration systems typically consist of a compressor, oil-water separator, water condenser, dryer filter, gas receiver, throttling unit, and cold trap connected sequentially in pipelines. While existing technologies employ variable frequency compressors and compressor energy regulation to improve energy efficiency, significant technical deficiencies remain regarding the core throttling regulation and liquid refrigerant supply and demand control aspects of the refrigeration cycle. Furthermore, the independent design of each component lacks coordinated control logic, resulting in low overall system energy efficiency, poor load adaptability, and insufficient operational stability. This makes it difficult to meet the stringent requirements of high-end industrial scenarios. Specific technical problems are as follows: 1. The throttling unit is poorly designed, resulting in low throttling efficiency and poor stability: Existing throttling units mostly use a single capillary tube or a series of fixed multi-stage capillary tubes. The throttling characteristics are fixed at the factory and cannot be dynamically adjusted according to the actual system load. Under light load, the throttling flow is too large, resulting in energy waste, while under heavy load, the throttling flow is insufficient, leading to a lack of cooling capacity. At the same time, there is no efficient gas-liquid separation structure before throttling. The gas-liquid two-phase mixture directly enters the capillary tube, which not only reduces the throttling pressure reduction effect but also causes system pressure fluctuations and low cold trap temperature control accuracy. Although some technologies propose the idea of ​​parallel capillary tubes in conjunction with solenoid valves, they have not formed an integrated module, resulting in loose component layout and high maintenance difficulty.

[0004] 2. Lack of dedicated liquid refrigerant storage and buffer structure, resulting in slow load response and severe pressure fluctuations: Existing refrigeration systems only have gas tanks to balance gaseous pressure, lacking a liquid refrigerant storage and buffer structure. Liquid refrigerant supply relies entirely on water condenser cooling and pipeline volume. When the load suddenly increases, refrigerant cannot be replenished quickly, resulting in low cooling efficiency of the cold trap. When the load decreases, excess refrigerant accumulates, causing pipeline pressure buildup. The severe pressure fluctuations caused by supply and demand imbalance can impact core components, leading to frequent compressor start-stop and reduced equipment lifespan.

[0005] 3. Low refrigerant utilization rate and affected capture effect: Relying on the pipeline volume to hold refrigerant can easily lead to refrigerant retention and waste, requiring more refrigerant to meet the demand, increasing the cost of use and posing a risk of compressor liquid slugging; at the same time, the unstable refrigerant circulation volume leads to temperature fluctuations in the cold trap, which can easily cause the captured water vapor to desorb, affecting the stability of the vacuum system.

[0006] Therefore, based on the above-mentioned technical problems, this application proposes an ultra-low temperature water vapor capture pump device that integrates liquid storage buffer and throttling to improve system dynamic response and achieve efficient distributed throttling and flow control. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide an ultra-low temperature water vapor capture pump device that integrates liquid storage buffer and throttling.

[0008] To achieve the above objectives, the present invention provides an ultra-low temperature water vapor capture pump device integrating liquid storage buffer and throttling, comprising a compressor, an oil separator, a water condenser, a dryer filter, a regenerator, multiple heat exchangers connected in series and a cold trap, wherein the compressor, oil separator, water condenser, dryer filter and regenerator are connected in series through a pre-set pipeline to form a circulating main liquid circuit. The device also includes at least one throttling module and a liquid storage module. One end of each throttling module is connected to the outlet of one of the heat exchangers, and the other end is connected to the heat exchange interface of the heat exchanger or other heat exchangers. The throttling module is used to perform gas-liquid separation and purification of the high-pressure liquid refrigerant transported in the main liquid circuit, and to controllably adjust the flow rate to match the load requirements of the main liquid circuit in real time. The liquid storage module has its outlet connected to the main liquid path before or after the regenerator, and its inlet connected to the downstream of the water condenser or dryer filter. The liquid storage module is used to recyclably supply liquid refrigerant to the main liquid path.

[0009] Furthermore, each of the throttling modules includes a gas-liquid separator and a capillary tube assembly. The outlet of the heat exchanger is connected to the inlet of the gas-liquid separator through a corresponding pipeline. The inlet of each capillary tube assembly is connected to the output of the corresponding gas-liquid separator, and the output of each capillary tube assembly is connected to the heat exchange interface of the plate heat exchanger or the input port of the downstream heat exchanger.

[0010] Furthermore, each of the capillary groups includes at least two capillary tubes arranged in parallel and at least two first solenoid valves respectively disposed on the corresponding capillary tubes for controlling the on-off state.

[0011] Furthermore, the heat exchanger is a plate heat exchanger.

[0012] Furthermore, the liquid storage module includes a liquid storage tank for storing liquid refrigerant, a delivery pipe, an inlet pipe, and a second solenoid valve. The liquid storage tank is connected to a connecting pipe before or after the regenerator via the delivery pipe. The second solenoid valve is installed on the delivery pipe and is used to control the on / off connection between the liquid storage tank and the main liquid circuit to input the liquid refrigerant in the liquid storage tank into the main liquid circuit. The liquid storage tank is connected to the downstream of the water condenser or dryer filter via the inlet pipe to draw liquid refrigerant from the downstream of the water condenser or dryer filter into the liquid storage tank.

[0013] Furthermore, the liquid storage tank is also equipped with a liquid level observation port for indicating the amount of liquid refrigerant in the tank.

[0014] Furthermore, the storage tank is equipped with a first pressure sensor for detecting the pressure inside the pipe.

[0015] Furthermore, the device also includes a gas storage tank, a gas delivery pipe, and a third solenoid valve for controlling the on / off state. The gas storage tank is connected to the connecting pipe between the regenerator and the compressor via the gas delivery pipe. The third solenoid valve is installed on the gas delivery pipe. The gas storage tank is used to regulate the pressure value of the main liquid circuit.

[0016] Furthermore, the device also includes an exhaust pipe and a fourth solenoid valve for controlling the on / off state. The two ends of the exhaust pipe are connected to a gas storage tank and a liquid storage tank, respectively, and the fourth solenoid valve is mounted on the exhaust pipe.

[0017] Furthermore, the device also includes a controller electrically connected to each solenoid valve, and the controller is used to control the opening and closing combinations of each solenoid valve.

[0018] The present invention adopts the above-described solution, and its beneficial effects are as follows: By setting up a liquid storage tank, which acts as a liquid refrigerant reservoir, the refrigerant can be quickly released when the system demand surges and excess refrigerant can be absorbed when the demand decreases. This effectively buffers the drastic fluctuations in system pressure, making the compressor's operating point more stable and improving the cooling speed and control accuracy.

[0019] The solenoid valve of the liquid receiver tank is intelligently controlled by the control unit and can be deeply integrated into the energy-saving operation logic of the whole machine. While the inverter and the energy-adjustable compressor work together to adjust the cooling capacity, by controlling the storage and release of the liquid receiver tank, the instantaneous demand of the system can be matched more precisely, avoiding the compressor from operating in the inefficient zone and achieving system-level energy efficiency optimization.

[0020] By setting up two gas-liquid separators to divide the refrigerant flow path into two, and configuring each with a set of independently controllable parallel capillary tubes, distributed management and fine adjustment of the flow rate are achieved. Furthermore, one or two sets of gas-liquid separator paths can be flexibly selected to be opened according to load requirements, as well as the number of parallel capillary tubes in each path, so that the throttling capacity is precisely matched with the system requirements, significantly reducing throttling losses under partial load.

[0021] After the refrigerant is initially cooled in the plate heat exchanger, it enters two independent gas-liquid separators for thorough gas-liquid separation, ensuring that the main refrigerant entering each capillary tube is liquid. This improves the stability and consistency of the throttling process and avoids the impact of uneven gas-liquid two-phase flow on the throttling effect. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the cryogenic water vapor capture pump device that integrates liquid storage buffer and throttling in this embodiment.

[0023] Among them, 1-throttling module, 11-gas-liquid separator, 12-capillary group, 121-capillary, 122-first solenoid valve, 2-liquid storage module, 21-liquid storage tank, 22-liquid delivery pipe, 23-liquid inlet pipe, 24-second solenoid valve, 3-gas storage tank, 4-gas delivery pipe, 5-third solenoid valve, 6-exhaust pipe, 7-fourth solenoid valve. Detailed Implementation

[0024] To facilitate understanding of the present invention, a more complete description is given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0025] See appendix Figure 1 As shown in this embodiment, an ultra-low temperature water vapor capture pump device integrating liquid storage buffer and throttling includes a compressor, an oil separator, a water condenser, a dryer filter, a regenerator, multiple heat exchangers (preferably plate heat exchangers) connected in series, and a cold trap. The compressor, oil separator, water condenser, dryer filter, and regenerator are connected in series through a pre-set pipeline to form a circulating main liquid circuit.

[0026] In this embodiment, the device further includes at least one throttling module 1 (the specific number of throttling modules 1 can be set according to the actual situation, and no specific limitation is made here) and a liquid storage module 2. One end of each throttling module 1 is connected to the outlet of one of the heat exchangers, and the other end is connected to the heat exchange interface of the heat exchanger or other heat exchangers. The throttling module 1 is used to perform gas-liquid separation and purification of the high-pressure liquid refrigerant transported by the main liquid circuit, and to controllably adjust the flow rate to match the load requirements of the main liquid circuit in real time.

[0027] Furthermore, each throttling module 1 includes a gas-liquid separator 11 and a capillary tube assembly 12. The outlet of the heat exchanger is connected to the inlet of the gas-liquid separator 11 via a corresponding pipeline. The inlet of each capillary tube assembly 12 is connected to the output of the corresponding gas-liquid separator 11, and the output of each capillary tube assembly 12 is connected to the heat exchange interface of the plate heat exchanger or the inlet of the downstream heat exchanger. Additionally, each capillary tube assembly 12 includes at least two parallel capillary tubes 121 and at least two first solenoid valves 122 respectively disposed on the corresponding capillary tubes 121 for controlling their on / off states. Figure 1 It is known that the high-pressure refrigerant liquid from the dryer filter and the gas storage tank 3 is first pre-cooled by the regenerator and then enters the throttling module 1 of this embodiment. After the refrigerant is further cooled by exchanging heat with the low-temperature return gas from the downstream in the plate heat exchanger, the gas-liquid mixture enters two gas-liquid separators 11 respectively. The liquid refrigerant accumulates at the bottom of the separator and is throttled and depressurized through the selected capillary tube 121 according to the control command (for example, only one capillary tube 121 and the solenoid valve on the capillary tube 121 are opened). The throttled low-temperature and low-pressure refrigerant enters the subsequent heat exchanger (or cold trap) to evaporate and absorb heat, and finally provides cooling capacity for the cold trap.

[0028] Furthermore, the device also includes a controller electrically connected to each solenoid valve. The controller controls the opening and closing combinations of each solenoid valve, enabling the control unit to receive temperature and pressure signals from corresponding locations on the device and determine the required cooling capacity accordingly. Its specific control logic can be preset in multiple modes: for example, under low load, only one gas-liquid separator 11 passage and one capillary tube 121 are opened; under medium load, both gas-liquid separator 11 passages are opened, but only one capillary tube 121 of each gas-liquid separator 11 is open; under high load, both gas-liquid separator 11 passages and... All 12 capillary tubes; through this combination, multi-level precise adjustment of cooling capacity from 25% to 100% is achieved, maximizing throttling efficiency under full load conditions, ensuring stable and consistent throttling process, and enhancing the overall energy efficiency of the refrigeration cycle through synergistic effect of heat exchange and throttling. Moreover, each stage operates at its high-efficiency point due to excellent gas-liquid separation and flow matching, completely solving the problems of poor load adaptability, large throttling losses, and unstable operation of traditional fixed throttling. This achieves energy saving and precise cooling control of the device, while improving the overall operational reliability and refrigeration cycle efficiency, and adapting to the high precision, high stability, and high energy efficiency requirements of high-vacuum industrial scenarios.

[0029] In this embodiment, the outlet of the liquid storage module 2 is connected to the main liquid path before or after the regenerator, and its inlet is connected to the downstream of the water condenser or dryer filter. The liquid storage module 2 is used to recyclably supply liquid refrigerant to the main liquid path. The liquid storage module 2 includes a liquid storage tank 21 for storing liquid refrigerant, a delivery pipe 22, an inlet pipe 23, and a second solenoid valve 24. The liquid storage tank 21 is connected to the connecting pipe before or after the regenerator through the delivery pipe 22. The second solenoid valve 24 is disposed on the delivery pipe 22 and is used to control the opening and closing between the liquid storage tank 21 and the main liquid path to input the liquid refrigerant in the liquid storage tank 21 into the main liquid path. The liquid storage tank 21 is connected to the water condenser or dryer filter through the inlet pipe 23. The second solenoid valve 24 is connected downstream of the main liquid circuit to draw liquid refrigerant from the downstream of the water condenser or dryer filter into the liquid storage tank 21. Specifically, when the main liquid circuit is in the first preset operating state, the second solenoid valve 24 is opened, allowing the liquid storage tank 21 to input a first preset amount of liquid refrigerant (the specific amount can be set according to the actual situation, and is not specifically limited here) into the main liquid circuit through the liquid delivery pipe 22. When the main liquid circuit is in the second preset operating state, the second solenoid valve 24 is closed, allowing the liquid storage tank 21 to draw a second preset amount of liquid refrigerant (the specific amount can be set according to the actual situation, and is not specifically limited here, and the amount drawn can be greater than, equal to or less than the input amount) into the tank.

[0030] Combination Figure 1The schematic diagram of the device piping shows that the high-pressure liquid refrigerant from the water condenser can be partially buffered in the storage tank 21 via the inlet pipe 23, while the other part flows directly to the subsequent circuit. When the control unit (such as a PLC) determines that a rapid increase in refrigerant supply is needed based on the corresponding sensor signals (i.e., the first preset operating state, specifically when the cold trap temperature is not up to standard and the load is high), it will issue a command to open the solenoid valve of the storage tank 21. At this time, the liquid refrigerant pre-stored in the storage tank 21 with a certain degree of subcooling will be rapidly injected into the main circuit through the delivery pipe 22, merging with the main liquid flow from the condenser to jointly supply the subsequent throttling evaporation unit, thereby rapidly increasing the refrigerant circulation volume and accelerating cooling. When the system enters stable operation or standby energy-saving mode (the second preset operating state), and the demand decreases, the control unit closes the solenoid valve of the storage tank 21, the storage tank 21 stops supplying liquid, and gradually replenishes itself from the main circuit to prepare for the next demand.

[0031] The aforementioned liquid storage module 2 significantly improves the system's dynamic response speed to sudden load changes and accelerates the cooling efficiency of the cold trap; it effectively smooths out fluctuations in refrigerant pressure and flow on the high-pressure side, ensuring the overall operational stability of the device; at the same time, it works in conjunction with the throttling module 1 to reduce ineffective work by the compressor and throttling losses, improving the overall energy efficiency of the device; secondly, it can improve the temperature control accuracy of the cold trap, ensuring the stability and consistency of water vapor capture effect; in addition, the liquid storage tank 21 and the throttling module 1 form an upstream and downstream synergy, further optimizing the adjustment accuracy and operating efficiency of the refrigeration cycle, and the integrated buffer design improves refrigerant utilization, avoids refrigerant waste and device failure risks, and is suitable for the long-term continuous, high-precision, and high-efficiency operation requirements of high-vacuum industrial scenarios.

[0032] Furthermore, the liquid storage tank 21 is also provided with a liquid level observation port for indicating the amount of liquid refrigerant in the tank, and the liquid storage tank 21 is provided with a first pressure sensor for detecting the pressure inside the pipe.

[0033] In this embodiment, the device also includes a gas storage tank 3, a gas transmission pipe 4, and a third solenoid valve 5 for controlling the on / off state, all located downstream of the water condenser. The gas storage tank 3 is connected to the connecting pipe between the regenerator and the compressor via the gas transmission pipe 4. The third solenoid valve 5 is located on the gas transmission pipe 4. The gas storage tank 3 is used to adjust the pressure value of the main liquid circuit. Furthermore, the gas storage tank 3 is equipped with a second pressure sensor for detecting the pressure inside the pipe (the pressure sensors are all configured to monitor the pressure inside each tank in real time to ensure that the liquid storage tank 21 / gas storage tank 3 is operating under normal conditions).

[0034] Furthermore, the device also includes an exhaust pipe 6 and a fourth solenoid valve 7 for controlling the on / off state. The two ends of the exhaust pipe 6 are connected to the gas storage tank 3 and the liquid storage tank 21, respectively. The fourth solenoid valve 7 is installed on the exhaust pipe 6. That is, when the main liquid circuit is running stably, the second solenoid valve 24 is closed. The liquid storage tank 21 needs to continuously draw in excess liquid refrigerant from the high-pressure main liquid circuit downstream of the condenser to complete the filling. If the liquid storage tank 21 is a closed structure without a gas balance port, the continuous entry of liquid refrigerant into the tank will compress the original gas in the tank, causing the gas phase pressure in the tank to rise rapidly, forming a pressure backflow with the main liquid circuit, ultimately preventing the liquid refrigerant from continuing to enter the tank and failing to complete the buffering. By setting the above-mentioned gas balance port, the upper gas phase space in the tank is connected to the low-pressure side of the main liquid circuit / gas storage tank 3, so that the compressed gas in the tank can be smoothly discharged through the gas balance port, so that the pressure in the tank is always slightly lower than the pressure of the high-pressure main liquid circuit, ensuring that the liquid refrigerant can continuously and smoothly enter the liquid storage tank 21 by relying on the pressure difference to complete the buffering and filling.

[0035] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any modifications or variations made by those skilled in the art, without departing from the scope of the present invention, using the disclosed technical content, are equivalent embodiments of the present invention. Therefore, all equivalent changes made based on the concept of the present invention without departing from the scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A cryogenic water vapor capture pump device integrating liquid storage buffer and throttling, comprising a compressor, an oil separator, a water condenser, a dryer filter, a regenerator, multiple heat exchangers connected in series, and a cold trap, wherein, The compressor, oil separator, water condenser, dryer filter, and regenerator are sequentially connected through pre-set pipelines to form a circulating main liquid circuit. The device is characterized in that: it further includes at least one throttling module (1) and a liquid storage module (2). One end of each throttling module (1) is connected to the outlet of one of the heat exchangers, and the other end is connected to the heat exchange interface of the heat exchanger or other heat exchangers. The throttling module (1) is used to perform gas-liquid separation and purification of the high-pressure liquid refrigerant transported by the main liquid circuit, and to controllably adjust the flow rate to match the load requirements of the main liquid circuit in real time. The outlet of the liquid storage module (2) is connected to the main liquid path before or after the regenerator, and its inlet is connected to the downstream of the water condenser or dryer filter. The liquid storage module (2) is used to recycle liquid refrigerant to the main liquid path.

2. The cryogenic water vapor capture pump device integrating liquid storage, buffering, and throttling according to claim 1, characterized in that: Each of the throttling modules (1) includes a gas-liquid separator (11) and a capillary tube assembly (12). The outlet of the heat exchanger is connected to the inlet of the gas-liquid separator (11) through a corresponding pipeline. The inlet of each capillary tube assembly (12) is connected to the output of the corresponding gas-liquid separator (11), and the output of each capillary tube assembly (12) is connected to the heat exchange interface of the plate heat exchanger or the input port of the downstream heat exchanger.

3. The cryogenic water vapor capture pump device integrating liquid storage buffer and throttling according to claim 2, characterized in that: Each of the capillary groups (12) includes at least two capillary tubes (121) arranged in parallel and at least two first solenoid valves (122) respectively arranged on the corresponding capillary tubes (121) for controlling the on and off.

4. The cryogenic water vapor capture pump device integrating liquid storage, buffering, and throttling according to claim 1, characterized in that: The heat exchanger is a plate heat exchanger.

5. The cryogenic water vapor capture pump device integrating liquid storage buffer and throttling according to claim 1, characterized in that: The liquid storage module (2) includes a liquid storage tank (21) for storing liquid refrigerant, a delivery pipe (22), an inlet pipe (23), and a second solenoid valve (24). The liquid storage tank (21) is connected to the connecting pipe before or after the regenerator through the delivery pipe (22). The second solenoid valve (24) is installed on the delivery pipe (22) and is used to control the opening and closing between the liquid storage tank (21) and the main liquid circuit, so as to input the liquid refrigerant in the liquid storage tank (21) into the main liquid circuit. The liquid storage tank (21) is connected to the downstream of the water condenser or dryer filter through the inlet pipe (23) so as to draw liquid refrigerant from the downstream of the water condenser or dryer filter into the liquid storage tank (21).

6. The cryogenic water vapor capture pump device integrating liquid storage buffer and throttling according to claim 5, characterized in that: The storage tank (21) is also provided with a liquid level observation port for indicating the amount of liquid refrigerant in the tank.

7. The cryogenic water vapor capture pump device integrating liquid storage buffer and throttling according to claim 5, characterized in that: The storage tank (21) is equipped with a first pressure sensor for detecting the pressure inside the pipe.

8. The cryogenic water vapor capture pump device integrating liquid storage buffer and throttling according to claim 5, characterized in that: The device also includes a gas storage tank (3), a gas transmission pipe (4), and a third solenoid valve (5) for controlling the on / off state. The gas storage tank (3) is connected to the connecting pipeline between the regenerator and the compressor through the gas transmission pipe (4). The third solenoid valve (5) is installed on the gas transmission pipe (4). The gas storage tank (3) is used to adjust the pressure value of the main liquid circuit.

9. The cryogenic water vapor capture pump device integrating liquid storage buffer and throttling according to claim 8, characterized in that: The device also includes an exhaust pipe (6) and a fourth solenoid valve (7) for controlling the on / off state. The two ends of the exhaust pipe (6) are connected to the gas storage tank (3) and the liquid storage tank (21) respectively, and the fourth solenoid valve (7) is installed on the exhaust pipe (6).

10. The cryogenic water vapor capture pump device integrating liquid storage buffer and throttling according to claim 1, characterized in that: The device also includes a controller electrically connected to each solenoid valve, and the controller is used to control the opening and closing combinations of each solenoid valve.

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