Temperature-controlled liquid storage tank and system

Abstract

This invention belongs to the field of aerospace electromechanical technology, specifically relating to a temperature-controlled liquid storage tank and system, including a tank body, a cooling element, and a heating rod. The tank body, cooling element, and heating rod are mounted on the cooling system circuit using a buffered three-way structure, without direct exchange of working fluid with the circuit. The heating rod is inserted at the bottom of the tank body, and the cooling element is located at the top of the tank body. A pressure sensor is installed inside the tank body. This invention realizes temperature control of a pump-driven two-phase flow cooling system, adjusts the working fluid pressure and subcooling at the pump inlet, and improves system stability, integration, and control accuracy. Through a compact structural design, it integrates multiple functions such as buffering, control, and filtration into one unit.

Description

Technical Field

[0001] This invention belongs to the field of aviation electromechanical technology, specifically relating to a temperature-controlled liquid storage tank and system. Background Technology

[0002] Airborne high-performance electronic equipment is sensitive to temperature, and its performance is closely related to the temperature control accuracy and uniformity of the cooling system.

[0003] Pump-driven two-phase flow cooling systems are an effective solution for cooling high-performance airborne electronic equipment. This system utilizes the latent heat of the working fluid during phase change to achieve heat transfer. Its heat load capacity is greater than that of single-phase cooling systems. At the same time, the temperature of the working fluid remains constant during heat absorption, and the evaporator surface has good temperature uniformity.

[0004] The liquid receiver plays a crucial role in a pump-driven two-phase flow cooling system. It is the core of the system, controlling the operating point, regulating the working fluid, and maintaining stable operation. Current technologies suffer from excessively large liquid receiver designs, insufficiently compact structures, high power consumption, and poor temperature control accuracy. Summary of the Invention The purpose of this invention is to propose a temperature-controlled liquid storage tank and system to achieve temperature control of a pump-driven two-phase flow cooling system, adjust the working fluid pressure and subcooling at the pump inlet, and improve system stability, integration and control accuracy. Through a compact structural design, it integrates multiple functions such as buffering, control and filtration.

[0005] The technical solution of this invention: A temperature-controlled liquid storage tank includes a tank body, a cooling element, and a heating rod, which are mounted on a cooling system circuit using a buffered three-way structure and do not directly exchange working fluid with the circuit; the heating rod is inserted at the bottom of the tank body, and the cooling element is located at the top of the tank body; a pressure sensor is installed inside the tank body.

[0006] Furthermore, the electric heating rod is inserted into the tank from the bottom to heat the working medium inside the tank.

[0007] Furthermore, the cooling chip is a semiconductor cooling chip, with the cold end attached to the top of the tank via thermally conductive adhesive, and the hot end cooled by forced air cooling and external air intake.

[0008] Furthermore, it also includes a filtration device, which is a filter element arranged at the outlet tee structure of the tank body, for filtering out impurities in the circuit.

[0009] Furthermore, it also includes a safety valve and a filling connector. The safety valve is a mechanical safety valve, located at the bottom of the tank, for automatic overpressure relief of the system. The filling connector is a quick-connect or quick-tighten high-pressure filling connector, located at the bottom of the tank. The pressure sensor is a high-precision pressure sensor, located at the bottom of the tank, for collecting pressure signals inside the tank.

[0010] Furthermore, a tempered glass sight glass window is provided on the side of the tank.

[0011] Furthermore, the tempered glass sight glass is sealed with a rubber sealing groove and fixed and clamped by a stainless steel cover plate.

[0012] Furthermore, the volume of the storage tank and the amount of working fluid filled satisfy the following conditions: when the circuit is in a fully liquid phase, the tank still retains liquid and maintains a two-phase state of gas and liquid; when the proportion of gas in the two-phase region of the pipeline is at its maximum, the tank can accommodate all the working fluid and retain a certain amount of gas phase space.

[0013] A pump-driven two-phase flow cooling system includes the aforementioned temperature-controlled liquid storage tank, and further includes an evaporator, a condenser, a pump, a filter, and a safety valve connected in sequence to form a cooling system loop. The temperature-controlled liquid storage tank is mounted on the cooling system loop via a buffer-type three-way structure.

[0014] Furthermore, by controlling the temperature of the working fluid inside the temperature-controlled liquid storage tank and the pressure at the corresponding location in the cooling system loop, the operating temperature of the evaporator is controlled. The temperature difference between the temperature-controlled liquid storage tank and the evaporator satisfies the following: ,in: The temperature of the working fluid inside the storage tank. The temperature of the working fluid inside the evaporator. For system loop pressure loss, For working fluid pressure Slope of the temperature saturation curve.

[0015] The beneficial effects of this invention are: The temperature-controlled liquid storage tank proposed in this invention, through integrated structural design and bidirectional temperature control strategy, has the following advantages compared to existing technologies: Achieving high-precision temperature and pressure coordinated control of a pump-driven two-phase flow cooling system indirectly regulates system pressure and evaporator operating temperature by controlling the temperature of the gas-liquid two-phase working fluid in the storage tank. This results in precise temperature control, fast response, and significantly improves the temperature uniformity and control stability of the airborne electronic equipment cooling system.

[0016] It has excellent system buffering and anti-fluctuation capabilities. It adopts a three-way buffer mounting structure, with the liquid storage tank and the main circuit pressure connected and the working fluid basically isolated. It can effectively suppress the pressure shock caused by airborne environment and load fluctuation, avoid violent system oscillation, and ensure the subcooling of the pump inlet and operational safety.

[0017] By rationally designing the working fluid charge and tank volume, the system maintains a stable two-phase state of gas and liquid within the tank under all operating conditions. This ensures that the system retains liquid working fluid even under extreme conditions of full liquid phase, and can accommodate all working fluid and retain gas phase space under maximum gas content conditions, thus maintaining a saturated state and ensuring the continuous effectiveness of temperature control and buffering functions.

[0018] With bidirectional heating and cooling adjustment, it adapts to a wide temperature range of airborne environments. It adopts a bottom-inserted heating rod to achieve rapid heating, and a top semiconductor cooling chip to achieve active cooling. The two work together in a time-sharing manner, which can stably control the temperature under all operating conditions such as low temperature start-up and high temperature and heavy load, solving the problem of insufficient adjustment range of single temperature control methods.

[0019] With its compact structure and high integration, it meets the stringent requirements of airborne aviation by integrating functions such as temperature control, buffering, filtration, safety protection, pressure monitoring, working fluid filling, and liquid level observation into one unit, significantly reducing size and weight, lowering system power consumption, and meeting the design requirements of high integration, high reliability, and lightweight for aviation electromechanical systems.

[0020] The system's safety and reliability are significantly improved. An outlet filter is installed to prevent impurities from clogging and causing wear. A mechanical safety valve is equipped at the bottom to automatically release overpressure. A high-precision pressure sensor monitors the status in real time, and a tempered glass sight glass facilitates liquid level observation and maintenance. Multiple safeguards enhance the system's lifespan and safety. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the pump-driven two-phase flow cooling system of the present invention; Figure 2 This is a schematic diagram of the temperature-controlled liquid storage tank structure of the present invention. Detailed Implementation

[0022] The following description of the embodiments further illustrates the specific implementation of the present invention in detail, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention: One embodiment of the present invention is as follows: Figure 2 As shown, a temperature-controlled liquid storage tank is provided for use in a pump-driven two-phase flow cooling system. It includes a tank body 1, a cooling element 2, a heating rod 3, a filter device, a safety valve 4, a pressure sensor 5, a filling connector 6, and a tempered glass sight glass 7. The tank body adopts a buffer-type three-way structure 8 and is mounted on the cooling system loop, without direct exchange of working fluid with the loop. The heating rod 3 is inserted into the tank body 1 from the bottom, and the cooling element 2 is installed on the top of the tank body 1. The filter device is located at the outlet of the tank body 1, the safety valve 4, pressure sensor 5, and filling connector 6 are located at the bottom of the tank body 1, and the tempered glass sight glass 7 is located on the side of the tank body 1.

[0023] When the airborne environment or load fluctuates, the system may experience drastic changes in state. The liquid receiver adopts a buffer structure that is mounted on the circuit using a three-way structure 8. There is no direct exchange of working fluid between the liquid receiver and the circuit. The two-phase state inside the liquid receiver does not affect the subcooling state of the refrigerant in the circuit, which can effectively maintain the stable operating state of the system and provide a buffer function for the system.

[0024] The working fluid inside the storage tank is always in a two-phase state. "Two-phase state" means that the cooling working fluid inside the storage tank exists in both "liquid" and "gas" states simultaneously, that is, a state in which liquid and gas coexist. The working fluid in the tank is neither a pure liquid nor a pure gas, but a mixture of liquid and gas, which are in a state of saturated equilibrium.

[0025] The purpose of keeping the working fluid in the storage tank in a two-phase state includes: Providing pressure buffering capacity: The gas inside the tank is a compressible "elastic space." When the system pressure suddenly increases, the gas is compressed, absorbing the pressure shock; when the pressure decreases, the gas expands, replenishing the pressure. If the tank is entirely composed of liquid (single-phase), it is almost incompressible and cannot provide a buffering effect.

[0026] Achieving temperature and pressure linkage control: In a two-phase system, the saturation pressure and saturation temperature of the working fluid are in one-to-one correspondence. For example, when heating the working fluid in the tank, the temperature rises, and the saturation pressure rises accordingly; when cooling, the temperature decreases, and the pressure decreases. By controlling the tank temperature in this way, the pressure in the system loop can be indirectly controlled.

[0027] Adapting to changes in system operating conditions: The state of the working fluid in the pipeline will change under different loads and temperatures. Maintaining a two-phase state inside the tank can accommodate excess liquid or gas, maintain the working fluid balance of the entire system, and prevent pump inlet cavitation or system overpressure.

[0028] The volume of the storage tank and the amount of working fluid filled satisfy the following conditions: when the circuit is in a fully liquid phase, the tank still retains liquid and maintains a two-phase state of gas and liquid; when the proportion of gas in the two-phase region of the pipeline is at its maximum, the tank can accommodate all the working fluid and retain a certain amount of gas phase space, and there is a certain amount of gas present.

[0029] like Figure 2 As shown, the tee structure 8 is located on the left side of the tank and is the core interface connecting the liquid storage tank to the main circuit of the cooling system. This structure is a typical bypass tee, with three connecting ports in its internal flow channel: (1) Main loop inlet / outlet: Directly connected to the system cooling pipeline, it is the main flow channel of the working fluid. The working fluid flows in / out from here and does not directly enter the tank or only a small part enters the tank. That is, the working fluid in the main loop flows through the main channel of the tee and does not directly enter the liquid storage tank, so as to avoid the two-phase state in the tank from affecting the subcooling and flow stability of the main loop.

[0030] (2) Storage tank connection port: A bypass branch leading out from the main circuit channel, which is directly connected to the gas-liquid two-phase space inside the storage tank.

[0031] (3) Buffer chamber (tank interior space): that is, the interior of the liquid storage tank body, which is connected to the main circuit pressure through the bypass port, but the working fluid is not directly exchanged. That is, the pressure of the main circuit is transmitted to the interior of the liquid storage tank through the bypass branch, so that the gas-liquid two-phase space inside the tank and the main circuit maintain pressure balance. The working fluid of the main circuit will not flow into the tank in large quantities, and the working fluid inside the tank will not enter the main circuit in large quantities. Pressure balance is achieved only through the small transmission of gas / liquid phase.

[0032] The inside of the storage tank is a two-phase gas-liquid state. When the pressure in the main circuit fluctuates: When the main circuit pressure increases: the main circuit pressure is transmitted to the tank through the bypass port, the gas phase space inside the tank is compressed, the excess pressure is absorbed, and the system is prevented from overpressure.

[0033] When the pressure in the main circuit decreases: the working medium inside the tank is heated by the heating rod, the gas phase inside the tank expands, and the pressure is replenished to the main circuit, suppressing the pressure drop, ensuring the pump inlet pressure is stable, and preventing cavitation.

[0034] Meanwhile, the liquid storage tank controls the temperature of the working fluid inside the tank through the heating rod 3 and the cooling plate 2, thereby changing the saturation pressure inside the tank. Due to the pressure connection characteristics of the three-way structure 8, the pressure change inside the tank is synchronously transmitted to the main circuit, thus achieving indirect control of the main circuit pressure and the evaporator operating temperature.

[0035] This structure achieves the function of "main circuit working fluid flow and connection with tank pressure", which does not interfere with the flow rate and subcooling state of the main circuit, and allows the gas-liquid space inside the tank to play a pressure buffering role.

[0036] In this embodiment, the liquid storage tank is heated by internal heating, with three electric heating rods inserted from the bottom of the tank to directly heat the working fluid inside. Compared with external heating, this can effectively improve the system pressure change rate.

[0037] The cooling requirement of the liquid storage tank mainly depends on the rate of temperature change of the cold source. The subcooling at the inlet of the system's working fluid pump must remain constant only if the rate of temperature change of the liquid storage tank is greater than or equal to the rate of temperature change of the cold source. The liquid storage tank is cooled by a semiconductor cooling chip 2, installed on the top of the tank. The cold end of the semiconductor chip is directly bonded to the smooth top of the tank body 1 using thermally conductive adhesive. The hot end is cooled by forced air cooling and external air intake to ensure the normal operation of the cooling chip.

[0038] The cooling element 2 and the electric heating rod 3 enable bidirectional temperature regulation of the liquid storage tank, allowing for both active heating and cooling. When the system working fluid temperature is low (e.g., during cold starts or in low-temperature environments), or when it is necessary to actively increase the pressure inside the tank or raise the operating temperature of the evaporator, rapid heating of the working fluid is required. The heating rod 3 is a direct contact heating method that inserts directly into the working fluid, offering fast response and high efficiency, enabling a rapid increase in both the temperature and pressure inside the tank.

[0039] When the system working fluid temperature is too high (such as high load heat generation, high temperature environment), or when it is necessary to actively reduce the pressure inside the tank and reduce the operating temperature of the evaporator, active cooling is required. The semiconductor cooling chip 2 is attached to the top of the tank 1 and achieves cooling by contacting the tank 1 with the cold end and dissipating heat with the hot end, which can control the temperature inside the tank to a level lower than the ambient temperature.

[0040] The external controller controls the operation of the heating rod 3 and the cooling element 2 in a time-sharing and on-demand manner based on the target temperature and the actual temperature inside the tank: when the temperature inside the tank is lower than the target temperature, the heating rod 3 is turned on and the cooling element 3 is turned off to rapidly raise the temperature; when the temperature inside the tank is higher than the target temperature, the cooling element 2 is turned on and the heating rod 3 is turned off to actively lower the temperature; when the temperature inside the tank is close to the target temperature, both can be turned off, and the temperature can be maintained by natural heat dissipation / insulation, or low-power fine-tuning can be used, such as the cooling element operating with a micro-current and the heating rod pulse heating.

[0041] If only heating element 3 is used, it can only raise the temperature, not lower it. When the system load is high and the ambient temperature is high, the temperature inside the tank will continue to rise, making it impossible to lower the temperature, which will lead to excessive system pressure and uncontrolled evaporator temperature. If only refrigerant element 2 is used, it can only lower the temperature, not raise it rapidly. In cold start or low-temperature environments, the temperature and pressure inside the tank will not rise, resulting in insufficient pump inlet pressure, the system being unable to establish a normal operating point, and the evaporator temperature being unable to be increased by raising the temperature.

[0042] Only by combining the two can bidirectional temperature control be achieved across all operating conditions, from low to high temperatures, ensuring that the system can work stably under different loads and environments.

[0043] In this embodiment, the filtration device is a filter element, arranged at the outlet tee structure 8 of the tank 1, used to filter out impurities in the circuit. This ensures the cleanliness of the fluid, filters out mechanical impurities mixed in the working fluid, and thus prevents system blockage, wear, and other malfunctions.

[0044] In this embodiment, a mechanical safety valve 4 is arranged at the bottom of the liquid storage tank to automatically release the internal high pressure before the abnormal high pressure of the system is generated, thereby improving the safety of the entire pump-driven two-phase flow cooling system.

[0045] In this embodiment, a high-precision pressure sensor 5 is arranged at the bottom of the liquid storage tank to collect, process, amplify, and upload the pressure signal inside the tank. The working fluid inside the tank is in a two-phase state, with a saturation pressure corresponding to a saturation temperature. The higher precision of the pressure sensor 5 allows for better control accuracy.

[0046] In this embodiment, a high-pressure filling connector 6 is arranged at the bottom of the liquid storage tank. It adopts a quick-connect / quick-tight design to achieve quick connection and disconnection with the high-pressure filling equipment.

[0047] In this embodiment, a tempered glass sight glass 7 is arranged on the side of the storage tank, which can effectively observe the liquid level of the working fluid in the storage tank, providing a reference for confirming the filling volume and the remaining working fluid during system operation. The tempered glass is sealed to the tank body using a sealing groove rubber sealing structure, and then fixed and clamped with a stainless steel cover plate.

[0048] A second embodiment of the present invention provides a pump-driven two-phase flow cooling system, including the aforementioned temperature-controlled liquid storage tank, and further including an evaporator, a condenser, a pump, a filter, and a safety valve connected in sequence to form a cooling system loop. The temperature-controlled liquid storage tank is mounted on the cooling system loop via a buffer three-way structure.

[0049] In this embodiment, the pressure at the location of the liquid storage tank in the loop is controlled by controlling the temperature of the liquid storage tank. Since the working fluid in both the evaporator and the liquid storage tank is in a two-phase state, the pressure difference between them represents the temperature difference. Therefore, controlling the temperature of the liquid storage tank controls the operating temperature of the evaporator, thereby achieving system control. The temperature difference between the evaporator and the liquid storage tank can be calculated using the following formula: By controlling the temperature of the working fluid inside the temperature-controlled liquid storage tank, the pressure at the corresponding location in the cooling system loop is controlled, thus achieving evaporator operating temperature control. The temperature difference between the temperature-controlled liquid storage tank and the evaporator satisfies: ,in: The temperature of the working fluid inside the storage tank. The temperature of the working fluid inside the evaporator. For system loop pressure loss, For working fluid pressure Slope of the temperature saturation curve.

[0050] In summary, this method enables temperature control of a pump-driven two-phase flow cooling system, adjusts the pump inlet working fluid pressure and subcooling, and improves system stability, integration, and control accuracy.

[0051] It should be noted that the above embodiments are merely illustrative examples of the present invention, intended to help understand the technical solution and core ideas of the present invention. Those skilled in the art should understand that any modifications, equivalent substitutions, or improvements made based on the concept of the present invention without departing from its principles should be considered within the scope of protection of the present invention, and the specific scope of protection is determined by the claims.

Claims

1. A temperature-controlled liquid storage tank, characterized in that, The device includes a tank, a cooling element, and a heating rod, which are mounted on the cooling system circuit using a buffered three-way structure and do not directly exchange working fluid with the circuit. The heating rod is inserted at the bottom of the tank, and the cooling element is located at the top of the tank. A pressure sensor is installed inside the tank.

2. The temperature-controlled liquid storage tank according to claim 1, characterized in that, The electric heating rod is inserted into the tank from the bottom to heat the working medium inside the tank.

3. The temperature-controlled liquid storage tank according to claim 1, characterized in that, The cooling chip is a semiconductor cooling chip, with the cold end attached to the top of the tank via thermally conductive adhesive, and the hot end cooled by forced air cooling and external air intake.

4. The temperature-controlled liquid storage tank according to claim 1, characterized in that, It also includes a filtration device, which is a filter element arranged at the outlet tee of the tank body to filter out impurities in the circuit.

5. The temperature-controlled liquid storage tank according to claim 1, characterized in that, It also includes a safety valve and a filling connector. The safety valve is a mechanical safety valve, located at the bottom of the tank, for automatic overpressure relief of the system. The filling connector is a quick-connect or quick-tighten high-pressure filling connector, located at the bottom of the tank. The pressure sensor is a high-precision pressure sensor, located at the bottom of the tank, for collecting pressure signals inside the tank.

6. The temperature-controlled liquid storage tank according to claim 1, characterized in that, The tempered glass sight glass is provided on the side of the tank.

7. The temperature-controlled liquid storage tank according to claim 1, characterized in that, The tempered glass sight glass is sealed with a rubber sealing groove and fixed and clamped by a stainless steel cover plate.

8. The temperature-controlled liquid storage tank according to claim 1, characterized in that, The volume of the storage tank and the amount of working fluid filled satisfy the following conditions: when the circuit is in a fully liquid phase, the tank still retains liquid and maintains a two-phase state of gas and liquid; when the proportion of gas in the two-phase region of the pipeline is at its maximum, the tank can accommodate all the working fluid and retain a certain amount of gas phase space.

9. A pump-driven two-phase flow cooling system, comprising a temperature-controlled liquid storage tank as described in any one of claims 1-8, characterized in that, It also includes an evaporator, a condenser, a pump, a filter, and a safety valve that are connected sequentially to form a cooling system loop. The temperature-controlled liquid storage tank is mounted on the cooling system loop via a buffer three-way structure.

10. The system according to claim 9, characterized in that, By controlling the temperature of the working fluid inside the temperature-controlled liquid storage tank and the pressure at the corresponding location in the cooling system loop, the operating temperature of the evaporator is controlled. The temperature difference between the temperature-controlled liquid storage tank and the evaporator satisfies the following requirements: ,in: The temperature of the working fluid inside the storage tank. The temperature of the working fluid inside the evaporator. For system loop pressure loss, For working fluid pressure Slope of the temperature saturation curve.

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