Refrigeration system based on electromagnetic valve liquid level control

Abstract

The application discloses a kind of low-temperature refrigeration systems based on electromagnetic valve liquid level control, belong to low-temperature refrigeration technical application field, including compressor, condenser, liquid tank, liquid level sensor, controller, solenoid valve, evaporator.The system improves the scheme of expansion valve or capillary throttling expansion, sets up liquid tank to store condensed liquid refrigerant after condenser, measures liquid level by liquid level sensor, when liquid level reaches set position, outputs electric signal by controller, solenoid valve opens, liquid refrigerant is transported to evaporator to vaporize heat absorption, gaseous refrigerant continues to condense in condenser, there is always enough liquid-phase refrigerant phase change vaporization in evaporator.Can avoid the problem of insufficient refrigerant flow caused by too small opening of expansion device in traditional throttling expansion, while liquid refrigerant entering evaporator is directly sucked by compressor inlet, forming low-temperature low-pressure refrigeration state, ensuring sufficient refrigerant flow and refrigeration capacity, controllable while realizing lower refrigeration temperature.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of low-temperature refrigeration technology, and particularly relates to a refrigeration system based on electromagnetic valve liquid level control. BACKGROUND

[0002] Compressed vapor refrigeration is a working process of repeatedly compressing, condensing, expanding and evaporating refrigerant in a closed refrigeration system to realize cooling and refrigeration, and is the most widely used in the current refrigeration industry. Through the consumption of electric energy, heat energy is transferred from low-temperature objects to high-temperature objects. In traditional refrigeration applications, the lowest effective refrigeration temperature that can be achieved by single-stage vapor compression is usually above -40℃ (233K). If a lower refrigeration temperature is to be achieved, such as in low-temperature cold storage and gas liquefaction scenarios, the refrigerant needs to reach a lower evaporation pressure to achieve a lower temperature.

[0003] The expansion process of the traditional refrigeration cycle needs to be realized by throttling expansion valves or capillary tubes to expand and reduce the pressure of the high-pressure refrigerant. The enthalpy value before and after this process remains unchanged, but a large amount of kinetic energy is lost through friction during the pressure reduction process, resulting in a decrease in energy efficiency. At the same time, to achieve lower refrigeration temperature and pressure, the opening degree is usually low to achieve greater refrigerant pressure drop. Considering that the throttling expansion valve and capillary tube need to rapidly contract through the refrigerant pipeline to achieve pressure reduction, the high-pressure liquid refrigerant produced by the condenser will experience significant congestion when passing through the narrow pipe diameter, resulting in a significant decrease in refrigerant flow through the throttling device to the subsequent evaporation link, and insufficient refrigeration capacity.

[0004] To overcome the above problems of the traditional refrigeration cycle, a new type of compressed vapor refrigeration system is proposed. In this system, the liquid refrigerant of the condenser is not passed through a throttling device, but is directly input into the evaporator and undergoes violent expansion and phase change vaporization in the evaporator through the suction of the compressor. In this way, sufficient refrigerant flow can be maintained while ensuring low evaporation pressure and temperature. To achieve control and adjustment of the refrigeration system, the liquid level sensor measures the real-time liquid level in the condenser, and the controller adjusts the amount and interval of refrigerant discharged to the evaporator to achieve the purpose of adjusting the evaporation temperature and refrigeration capacity. SUMMARY

[0005] Therefore, the application provides a refrigeration system based on electromagnetic valve liquid level control, and the specific technical scheme is as follows:

[0006] A refrigeration system based on electromagnetic valve liquid level control is composed of a compressor, a condenser, a liquid storage tank, a liquid level sensor, a controller, an electromagnetic valve, an evaporator and the like.

[0007] Among them, for the flow pipeline of the refrigerant, the outlet of the compressor is connected with the inlet of the condenser, the outlet of the condenser is connected with the inlet of the evaporator, and the outlet of the evaporator is connected with the inlet of the compressor.

[0008] The liquid storage tank inlet is connected, the liquid storage tank outlet is connected with the electromagnetic valve inlet, the electromagnetic valve outlet is connected with the evaporator refrigerant inlet, and the evaporator refrigerant outlet is connected with the compressor inlet;

[0009] The liquid level sensor is fixedly installed on the inner or outer surface of the liquid storage tank according to actual working needs, and the height can be set according to actual needs. The sensor is connected with the controller and the electromagnetic valve through a circuit. When the liquid level in the liquid storage tank does not reach the set height, the sensor is in an open circuit state, the system does not produce action, and the refrigerant pipeline at the electromagnetic valve is in a closed state. When the liquid level reaches the set position of the sensor, the sensor outputs an electric signal to close, the relay in the controller is attracted, and then a signal is output to the electromagnetic valve to open, so that the refrigerant passes through. When the liquid level is lower than the set position, the liquid level sensor is opened again, the control signal is disconnected, the electromagnetic valve returns to the closed state, and then the periodic repeated work is performed.

[0010] Another object of the present application is to provide a use method of the above-mentioned system, and the main working process includes:

[0011] In the refrigeration process, the high-temperature and high-pressure refrigerant output by the compressor is input into the condenser for cooling and liquefaction, and then the refrigerant is input into the liquid storage tank. At the beginning, the liquid level does not reach the height of the liquid level sensor, the electromagnetic valve is in a closed state, and the liquid is stored in the liquid storage tank. When the liquid level reaches the position of the liquid level sensor, the sensor outputs an electric signal to close, the electromagnetic valve is opened through the controller, the liquid refrigerant in the liquid storage tank is discharged to the evaporator in time, and the electromagnetic valve is closed again after the liquid level decreases. Under the strong suction of the compressor, the liquid refrigerant is forced to expand, the pressure and temperature are reduced, the input air is heat-exchanged and cooled, the refrigerant after heat absorption and vaporization is input into the compressor again, and one refrigeration cycle is completed.

[0012] Further, the height position of the liquid level sensor can be adjusted according to the actual system power and the refrigerant filling amount, and the liquid discharge time length of the electromagnetic valve after each power-on conduction can also be set according to the needs.

[0013] Further, the liquid level sensor can adopt and is not limited to a plurality of working types such as a floating ball type, a floating cylinder type, a static pressure type, a capacitive type and an optical type.

[0014] Further, the present application can be applied to the refrigeration needs of various gas and liquid working substances including air.

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] The liquid level measurement is combined with the electromagnetic valve control in the refrigeration cycle innovatively, the traditional throttling expansion valve and capillary tube are replaced, the gas-liquid component relationship of the refrigerant between the condenser and the evaporator is regulated, the liquid refrigerant in the condenser is directly delivered to the evaporator without throttling, and the evaporator always keeps enough liquid phase refrigerant for phase change vaporization. The scheme can avoid the problem of insufficient refrigerant flow caused by too small opening degree of the expansion device in the traditional throttling expansion, the liquid refrigerant entering the evaporator is directly sucked through the compressor inlet to form a significant low-temperature and low-pressure state, the sufficient and controllable refrigerant flow and refrigeration capacity are ensured, and lower refrigeration temperature is realized, so that the scheme has good application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on the provided drawings.

[0018] Fig. 1 is a schematic diagram of a refrigeration system based on electromagnetic valve liquid level control according to the present application;

[0019] Reference signs:

[0020] 1-compressor, 2-condenser, 3-liquid storage tank, 4-liquid level sensor, 5-controller, 6-electromagnetic valve, 7-evaporator, 8-input air. DETAILED DESCRIPTION

[0021] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0022] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0023] In addition, the terms "first", "second", etc. are used only for descriptive purposes and do not connote or imply relative importance or an ordering between or among the indicated technical features. Thus, a feature defined with "first" or "second" can include one or more of the features explicitly or implicitly. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise expressly and specifically defined.

[0024] Embodiment 1, as shown in Figure 1, a refrigeration system based on solenoid valve liquid level control includes compressor 1, condenser 2, liquid tank 3, liquid level sensor 4, controller 5, solenoid valve 6, evaporator 7. Among them, for the flow of refrigerant circuit, compressor 1 outlet and condenser 2 inlet connected, condenser 2 outlet and liquid tank 3 inlet connected, liquid tank 3 outlet and solenoid valve 6 inlet connected, solenoid valve 6 outlet and evaporator 7 refrigerant inlet connected, evaporator 7 refrigerant outlet and compressor 1 inlet connected.

[0025] The liquid level sensor 4 in the system is fixedly installed inside or outside the liquid tank 3 according to actual work needs

[0026] The height can be set according to actual needs. The liquid level sensor 4 is connected to the controller 5 and the solenoid valve 6 through an electric circuit. When the liquid level in the liquid tank 3 does not reach the set height, the liquid level sensor 4 is in an open circuit state, the system does not produce action, and the refrigerant pipeline at the solenoid valve 6 is in a closed state. When the liquid level reaches the sensor set position, the refrigerant liquid pushes the float, lever and other mechanical structures of the liquid level sensor 4, making the liquid level sensor 4 close and output an electric signal, making the relay in the controller 5 attract, and then outputting a signal to the solenoid valve 6 to open it, so that the refrigerant passes through. When the liquid level is lower than the set position, the liquid level sensor 4 is open again, the control signal is disconnected, and the solenoid valve 6 returns to the closed state, and then the periodic repetition work is carried out.

[0027] In the system refrigeration process, the high-temperature and high-pressure refrigerant output by the compressor 1 is input into the condenser 2 to be cooled and liquefied, and then the refrigerant is input into the liquid storage tank 3. Initially, the liquid level does not reach the height of the liquid level sensor, and the electromagnetic valve 6 is in a closed state. The liquid is stored in the liquid storage tank 3, and the liquid level gradually rises. When the liquid level reaches the position of the liquid level sensor 4, the float enters the detection range of the measuring head, the sensor closes the output electrical signal, and the electromagnetic valve 6 is opened through the controller 5. The liquid refrigerant in the liquid storage tank 3 is discharged into the evaporator 7 in time, and the electromagnetic valve 6 is closed again after the liquid level drops. Under the strong suction of the compressor 1, the liquid refrigerant is forced to expand and reduce pressure in the evaporator 7, the temperature is lowered, the input air 8 on the hot side is heat-exchanged and cooled, and the heat-absorbed and vaporized refrigerant is input into the compressor 1 again to complete a refrigeration cycle.

[0028] In the embodiment of the application, the height position of the liquid level sensor 4 can be adjusted according to the actual system power and the refrigerant charging amount, and the liquid discharge time of the electromagnetic valve after each power-on conduction can also be set according to the demand. Under the cooperation of the electromagnetic valve and the liquid level meter, intermittent liquid supplement to the evaporator 7 is realized. When the evaporation amount required in the evaporator 7 is large, the height of the liquid level meter can be appropriately lowered to shorten the interval of the on-off switching of the electromagnetic valve 6 and improve the frequency of liquid supplement to the evaporator 7. Although the refrigerant flow in the evaporator 7 increases during the conduction period, the evaporation pressure rises and the evaporation temperature rises, and the refrigeration effect decreases, so the liquid discharge time of the electromagnetic valve 6 after each power-on should not be too long and needs to be flexibly set.

[0029] In the embodiment of the application, the liquid level sensor 4 can adopt but is not limited to multiple working types such as float ball type, float cylinder type, static pressure type, capacitance type and optical type, and the actual selection can be flexibly selected according to the working conditions and the working medium type. When the liquid surface in the liquid storage tank 3 changes, the liquid level sensor 4 forms a closed or open state due to the action of the liquid surface, outputs a high-level or low-level control signal to the controller end, and controls the on-off of the electromagnetic valve 6 through a logic circuit. In addition to automatic control through the liquid level sensor, the controller 5 can also realize level output regulation and control through active control, improving the controllability of the system.

[0030] In the embodiment of the application, the application can be applied to the refrigeration demand of various gas and liquid working media including air and water.

[0031] In the embodiment of the application, the type of refrigerant can be flexibly selected according to the actual refrigeration temperature demand range.

[0032] In the embodiment of the application, the pipes involved have good pressure resistance and heat preservation performance, and can withstand high pressure and low temperature, high temperature conditions for a long time.

[0033] Embodiment 2, as shown in FIG. 1, a refrigeration system based on electromagnetic valve liquid level control, comprising a condenser 2, a compressor 1 and an evaporator 7, the system is also provided with:

[0034] A liquid storage tank 3, the liquid storage tank inlet is connected with the condenser outlet, and the liquid storage tank outlet is connected with the electromagnetic valve 6 inlet; an electromagnetic valve 6, the electromagnetic valve outlet is connected with the evaporator refrigerant inlet;

[0035] A liquid level sensor 4 for monitoring the liquid level in the liquid storage tank;

[0036] A controller 5, the controller is electrically connected with the liquid level sensor 4 and the electromagnetic valve 6.

[0037] The high-temperature and high-pressure refrigerant output by the compressor 1 is liquefied by the condenser 2 and then enters the liquid storage tank 3, when the liquid level sensor 4 detects that the liquid level reaches the set height, the controller 5 controls the electromagnetic valve 6 to open, so that the liquid refrigerant flows into the evaporator 7 for evaporation cooling, and the evaporated refrigerant enters the compressor 1 again to complete the refrigeration cycle.

[0038] In some embodiments, the liquid level sensor 4 is fixedly installed inside or on the outer surface of the liquid storage tank 3.

[0039] In some embodiments, the controller 5 controls the on-off state of the electromagnetic valve 6 according to the signal of the liquid level sensor 4.

[0040] In some embodiments, the liquid level sensor 4 is connected with the controller 5 through a circuit to transmit the liquid level information.

[0041] In some embodiments, the liquid level sensor 4 can be one of a float ball type, a float cylinder type, a static pressure type, a capacitive type or an optical type.

[0042] In some embodiments, according to the system power and the refrigerant charge, the installation position of the liquid level sensor 4 can be adjusted.

[0043] In some embodiments, the signal output by the liquid level sensor 4 controls the on-off state of the electromagnetic valve 6.

[0044] In some embodiments, the single liquid discharge time of the electromagnetic valve 6 can be set through the controller 5.

[0045] Furthermore, in this embodiment, R22 is used as the refrigerant, the volume of the liquid storage tank 3 is 2 L, and the liquid level sensor 6 is installed on the upper and lower end faces of the liquid storage tank 3. The liquid level sensor 6 is a capacitive type, and its output signal is a high potential, corresponding to a liquid level range of 0-10 cm. The set value of the controller 8 is equal to the output signal being a high potential, corresponding to a liquid level of 5 cm. When the signal of the liquid level sensor 6 is higher or lower than the set value, the controller 8 controls the solenoid valve 6 to close or open, respectively. The single drainage time of the solenoid valve 6 is 1 s.

[0046] The working process of this embodiment is as follows:

[0047] The compressor 1 is started, compressing the low-temperature, low-pressure refrigerant vapor output from the evaporator 7 into a high-temperature, high-pressure refrigerant.

[0048] The vapor is sent to condenser 1 for cooling;

[0049] In condenser 1, high-temperature and high-pressure refrigerant vapor exchanges heat with air, releasing heat into the environment, while condensing into liquid refrigerant, which flows into liquid storage tank 3 for storage.

[0050] When the liquid level in the liquid storage tank 3 is lower than 5 cm, the signal output by the liquid level sensor 6 is at a high potential, which is equal to the set value of the controller 8. At this time, the solenoid valve 6 is in the closed state and does not deliver liquid refrigerant to the evaporator 7.

[0051] When the liquid level in the liquid storage tank 3 reaches 5 cm, the signal output by the liquid level sensor 6 is less than 2.5 V. The controller 8 detects the signal change and controls the solenoid valve 6 to open, supplying liquid refrigerant to the evaporator 7. The solenoid valve 6 is open for 1 second each time.

[0052] In evaporator 7, liquid refrigerant exchanges heat with the input air, transferring the heat absorbed by the refrigerant to the input air, while evaporating into low-temperature, low-pressure refrigerant vapor, which flows back to compressor 1 for recompression, completing the refrigeration cycle;

[0053] When the liquid level in the liquid storage tank 3 is lower than 5 cm, the signal output by the liquid level sensor 6 is at a low potential. The controller 8 detects the signal change and controls the solenoid valve 6 to close, stopping the supply of liquid refrigerant to the evaporator 7. The above steps are repeated until the liquid level is lower than 5 cm again.

[0054] The various embodiments described in this specification are implemented in a progressive manner, each embodiment focusing on the differences from other embodiments, and the same or similar parts between embodiments can be mutually referred to. For the apparatus disclosed by the embodiments, since it corresponds to the method disclosed by the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0055] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those of ordinary skill in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A refrigeration system based on solenoid valve liquid level control comprising a condenser, a compressor and an evaporator, characterized in that, The system is also provided with; A liquid storage tank, the inlet of which is connected with the outlet of the condenser, and the outlet of which is connected with the inlet of the electromagnetic valve; An electromagnetic valve, the outlet of which is connected with the inlet of the evaporator; A liquid level sensor for monitoring the liquid level in the liquid storage tank; A controller, which is electrically connected with the liquid level sensor and the electromagnetic valve; The controller controls the on-off state of the electromagnetic valve according to the signal of the liquid level sensor; The single discharging time of the electromagnetic valve is set by the controller.

2. A refrigeration system based on solenoid valve liquid level control as claimed in claim 1 wherein, The liquid level sensor is fixedly installed on the inner or outer surface of the liquid storage tank.

3. A refrigeration system based on solenoid valve liquid level control as claimed in claim 1 wherein, The liquid level sensor is connected with the controller through an electric circuit to transmit the liquid level information.

4. A refrigeration system based on solenoid valve liquid level control as claimed in claim 1 wherein, The liquid level sensor is one of the following types: floating ball type, floating cylinder type, static pressure type, capacitance type and optical type.

5. A refrigeration system based on solenoid valve liquid level control as claimed in claim 1 wherein, The installation position of the liquid level sensor is adjusted according to the system power and the refrigerant charging amount.

6. A refrigeration system based on solenoid valve liquid level control as claimed in claim 1 wherein, The on-off state of the electromagnetic valve is controlled by the signal output by the liquid level sensor.

7. A refrigeration system based on solenoid valve liquid level control as claimed in claim 1 wherein, The high-temperature and high-pressure refrigerant output by the compressor is liquefied by the condenser and then enters the liquid storage tank. When the liquid level sensor detects that the liquid level reaches the set height, the controller controls the electromagnetic valve to open, so that the liquid refrigerant flows into the evaporator to be evaporated and cooled. The evaporated refrigerant enters the compressor again to complete the refrigeration cycle.

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