A device for preventing liquid impact on a heat pump system

Abstract

The present application relates to heat exchange equipment technical field, propose a kind of heat pump system anti-liquid device, including four-way valve, one end of the four-way valve is connected with compressor, one-way valve is provided in the air guide passage between the compressor and the four-way valve, the one-way valve is used to prevent refrigerant migration backflow to the compressor, the other end of the four-way valve is connected with supercooling structure, the supercooling structure is connected with heat exchange structure, when heat pump system is in refrigeration and defrosting mode, the supercooling structure passes through the heat flow path of the heat exchange structure to increase the supercooling degree of the full liquid shell tube heat exchanger, reduce the gas liquid amount of the full liquid shell tube heat exchanger, when heat pump system is switched from heating mode to defrosting mode, the supercooling structure passes through the internal air pressure balance of the heat exchange structure, prevents refrigerant into the compressor, reduces the risk that compressor and four-way valve connected with compressor are hit by liquid.

Description

Technical Field

[0001] This invention relates to the field of heat exchange equipment technology, and in particular to a device for preventing liquid hammer in a heat pump system. Background Technology

[0002] With the advancement of technology and the development of the times, heat pump air conditioners have entered thousands of households. Their basic principle is to use the working principle of heat pump cycle, which absorbs heat from a low-temperature heat source, then raises it and releases it to a high-temperature heat source to realize the transfer and conversion of heat energy. The heat pump air conditioning system is basically composed of four parts: evaporator, compressor, condenser and expansion valve.

[0003] Among them, the flooded shell-and-tube heat exchanger used in heat pump systems has advantages such as simplified internal structure and high heat exchange efficiency, and is widely used. Compared with other types of shell-and-tube heat exchangers, its refrigerant charge is very large. When switching from heating operation to defrost mode, the four-way valve actuates, causing the shell and tube on the high-pressure side to connect with the gas-liquid separator on the low-pressure side. This causes a large amount of liquid refrigerant to rush into the gas-liquid separator, resulting in excessive liquid return. Consequently, some liquid refrigerant enters the compressor. This not only dilutes the compressor lubricating oil and washes away the oil film on the friction surfaces, causing lubrication failure, but also leads to damage to the compression chamber due to excessive pressure.

[0004] In addition, the four-way valve is a component that enables the switching between cooling and heating modes in an air conditioner.

[0005] In heating mode, the four-way valve reversing line is connected. At this time, the indoor heat exchanger becomes the condenser, and the outdoor heat exchanger becomes the evaporator. The low-temperature, low-pressure superheated gas from the outdoor heat exchanger enters the gas-liquid separator through the four-way valve and the silencer. After the liquid is separated, the dry superheated gas is drawn into the compressor and compressed into high-temperature, high-pressure gas, which is then discharged. The gas enters the indoor heat exchanger through the four-way valve to release heat and condense (at this time, the indoor air is heated), becoming subcooled liquid. After the subcooled liquid is depressurized by the capillary tube resistance, it becomes a low-temperature, low-pressure two-phase fluid. It enters the outdoor heat exchanger to evaporate and absorb heat. Then, the superheated gas enters the next cycle through the four-way valve and the gas-liquid separator.

[0006] In cooling mode, the four-way valve reversing line is connected. At this time, the indoor heat exchanger becomes the evaporator, and the outdoor heat exchanger becomes the condenser. Low-temperature, low-pressure superheated gas from the indoor heat exchanger enters the gas-liquid separator via the four-way valve and silencer. After liquid separation, the superheated gas is drawn into the compressor and compressed into high-temperature, high-pressure gas, which is then discharged. This gas enters the outdoor heat exchanger via the four-way valve, releasing heat and condensing to become subcooled liquid. The subcooled liquid, after pressure reduction through the capillary tube, becomes a low-temperature, low-pressure two-phase fluid, entering the indoor heat exchanger for evaporation and heat absorption (at this time, the indoor air is cooled), and then passes through the four-way valve and gas-liquid separator again to enter the next cycle.

[0007] If the four-way valve malfunctions, the system will be unable to switch between cooling and heating modes, and may even cause the air conditioner to leak air and malfunction, resulting in high repair costs.

[0008] According to feedback from after-sales service, liquid slugging accounts for a certain percentage of four-way valve failures.

[0009] The common method to avoid liquid carryover during defrosting of flooded shell-and-tube evaporators is to install a dual gas separator. While this can effectively prevent liquid slugging in the compressor, it still has some shortcomings in actual use.

[0010] 1. When an air conditioning system is restarted after a long period of inactivity, refrigerant in both gas and liquid phases may flow through the four-way valve due to refrigerant migration and liquid carryover during the shutdown state. In this situation, when the four-way valve reverses its direction, liquid slugging in the compressor can easily occur, leading to damage to the four-way valve.

[0011] 2. The dual gas separator increases the difficulty of oil return, which can easily lead to abnormal oil return and reduce system reliability.

[0012] In view of this, the present invention proposes a method and apparatus for preventing liquid slugging in a heat pump system to solve the above-mentioned problems. Summary of the Invention

[0013] This invention provides a device for preventing liquid slugging in a heat pump system, which solves the problems of liquid carryover in the outlet gas of a flooded shell-and-tube heat exchanger and liquid slugging in the four-way valve when the air conditioner is started.

[0014] A device for preventing liquid slugging in a heat pump system includes a four-way valve.

[0015] A compressor is connected to one end of the four-way valve. A one-way valve is provided in the air guide passage between the compressor and the four-way valve. The one-way valve is used to prevent refrigerant from migrating back to the compressor.

[0016] The other end of the four-way valve is connected to a subcooling structure, which is connected to a heat exchange structure. When the heat pump system is in cooling and defrosting mode, the subcooling structure increases the subcooling degree of the flooded shell and tube heat exchanger and reduces the amount of liquid carried by the gas at the outlet of the flooded shell and tube heat exchanger by adjusting the heat flow path of the heat exchange structure.

[0017] When the heat pump system switches from heating mode to defrosting mode, the subcooling structure prevents refrigerant from entering the compressor by adjusting the internal pressure balance of the heat exchange structure.

[0018] Due to the function of the one-way valve, the refrigerant can only flow from the compressor outward through the four-way valve, and cannot flow from the four-way valve back to the compressor.

[0019] Preferably, an air guide passage is connected between the compressor and the D-connector of the four-way valve.

[0020] Preferably, when the four-way valve is in a de-energized state, the internal structure of the four-way valve changes, and the S-connector and E-connector are connected, and the D-connector and C-connector are connected.

[0021] When the four-way valve is powered on, the internal structure of the four-way valve changes, and the S-connector and C-connector are connected, and the D-connector and E-connector are connected.

[0022] Preferably, the end of the compressor furthest from the four-way valve is connected to a vapor-liquid separator, which is connected to two gas guide channels. One gas guide channel of the vapor-liquid separator is connected to the compressor via a compressor solenoid valve, and the other gas guide channel of the vapor-liquid separator is connected to the S-connector of the four-way valve.

[0023] Preferably, the heat exchange structure includes a flooded shell-and-tube heat exchanger and a storage tank. The flooded shell-and-tube heat exchanger includes a regenerating tube and a heat exchange tube disposed inside the tube. An inlet pipe is connected to one side of the heat exchange tube, and an outlet pipe is connected to one side of the regenerating tube. The regenerating tube is connected to two gas guiding channels. One gas guiding channel of the regenerating tube is connected to the storage tank, and the other gas guiding channel of the regenerating tube is connected to the inlet pipe. An electronic expansion valve is provided on the gas guiding channel connecting the regenerating tube and the inlet pipe.

[0024] In a flooded shell-and-tube heat exchanger, refrigerant flows inside the shell and tubes, refrigerant flows inside the heat recovery tubes, and water flows inside the remaining heat exchange tubes.

[0025] Preferably, the air guide channel connected to the fourth valve of the four-way valve is divided into two branches. One branch is connected to the liquid storage tank and is equipped with a liquid storage tank solenoid valve. The other branch is connected to the air outlet pipe and is equipped with a shell and tube pressure sensor.

[0026] Preferably, the subcooling structure includes a finned heat exchanger, which is connected to two air guide channels. One of the air guide channels of the finned heat exchanger is connected to the E-connector of the four-way valve, and the other air guide channel of the finned heat exchanger is connected to the liquid storage tank. A tank pressure sensor is installed on the air guide channel connecting the finned sensor and the liquid storage tank.

[0027] Preferably, the finned heat exchanger, the shell and tube pressure sensor, and the tank pressure sensor together form a subcooling structure.

[0028] A control method for a device for preventing liquid slugging in a heat pump system, the method comprising:

[0029] The four-way valve has two working states: "0" and "non-zero". The "0" state is the power-off state, and the "non-zero" state is the power-on state.

[0030] The pressure inside the liquid storage tank is monitored using the tank pressure sensor, and the pressure inside the vent pipe is monitored using the shell and tube pressure sensor.

[0031] When the compressor is turned on, the compressor solenoid valve opens accordingly. The state of the four-way valve is then determined based on whether the four-way valve is energized. The working state of the four-way valve is divided into a de-energized state and an energized state.

[0032] When the four-way valve is de-energized, compare the values ​​of the tank pressure sensor and the shell and tube pressure sensor.

[0033] If the value of the shell-and-tube pressure sensor is greater than the value of the tank pressure sensor, then the storage tank solenoid valve is opened.

[0034] If the value of the shell-and-tube pressure sensor is less than the value of the tank pressure sensor, then the storage tank solenoid valve is closed.

[0035] When the four-way valve is energized, the liquid storage tank solenoid valve is closed; or, when the compressor is turned off, the compressor solenoid valve closes, and the liquid storage tank solenoid valve closes as well.

[0036] When the unit is running, the compressor solenoid valve opens, and the refrigerant is diverted from the vapor-liquid separator to the compressor. When the unit stops running, the compressor solenoid valve closes, and the refrigerant cannot enter the compressor.

[0037] Compared with the prior art, the advantages of the present invention are as follows:

[0038] 1. In this invention, a check valve is installed between the compressor and the four-way valve. Due to the function of the check valve, the refrigerant can only flow from the compressor outward through the four-way valve and cannot flow from the four-way valve into the compressor. A compressor solenoid valve is installed between the compressor and the vapor-liquid separator. When the device is running, the compressor solenoid valve opens, and the refrigerant flows from the vapor-liquid separator to the compressor. When the device stops running, the compressor solenoid valve closes, and the refrigerant cannot enter the compressor. Through the cooperation between the check valve, the compressor, and the compressor solenoid valve, the risk of compressor liquid slugging is reduced, and the safety of the device is improved.

[0039] 2. In this invention, the pipeline between the finned heat exchanger and the electronic expansion valve is connected to the regenerator pipe. In the cooling and defrosting modes, the regenerator pipe exchanges heat with the outlet gas of the flooded shell and tube heat exchanger. While increasing the subcooling, it can effectively reduce the amount of liquid carried by the outlet gas. Through the cooperation of the finned heat exchanger and the electronic expansion valve, the risk of compressor liquid slugging in the cooling and defrosting modes is reduced.

[0040] 3. In this invention, when the device switches from heating mode to defrosting mode, the high-pressure refrigerant in the shell and tube can enter the liquid receiver tank through the liquid receiver tank solenoid valve, significantly reducing the amount of refrigerant entering the gas-liquid separator and quickly balancing the high and low pressures, effectively preventing a large amount of liquid refrigerant from entering the compressor. Once the high and low pressures are balanced, the liquid receiver tank solenoid valve is closed.

[0041] Simultaneously, after the solenoid valve of the liquid receiver tank is closed, the temperature of the regenerator tube rises rapidly, exchanging heat with the outlet gas of the flooded shell-and-tube heat exchanger, vaporizing the liquid refrigerant in the outlet gas. By balancing the high and low pressures and heating the outlet gas of the shell and tube, the problem of liquid slugging in the compressor caused by liquid in the outlet gas of the flooded shell and tube can be effectively solved, ensuring the practicality of the device.

[0042] 4. In this invention, by reducing the risk of liquid slugging in the compressor when the device is in both cooling and defrosting modes and when it transitions from heating mode to defrosting mode, the risk of liquid slugging in the four-way valve connected to the compressor is indirectly reduced.

[0043] 5. This invention proposes a control method for a device based on a heat pump system to prevent liquid slugging. Each structure is connected to a control unit. By judging the working status of each component, the device can autonomously enter different working states, thus ensuring the practicality of the device. Attached Figure Description

[0044] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0045] Figure 1 This is a system schematic diagram in an embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of a flooded shell-and-tube heat exchanger structure in an embodiment of the present invention;

[0047] Figure 3 This is an internal layout diagram of a flooded shell-and-tube heat exchanger in an embodiment of the present invention;

[0048] Figure 4 This is a working logic diagram in an embodiment of the present invention.

[0049] Figure label:

[0050] 1. Four-way valve;

[0051] 2. Compressor;

[0052] 3. Check valve;

[0053] 4. Subcooling structure; 41. Finned heat exchanger; 42. Shell and tube pressure sensor; 43. Tank pressure sensor;

[0054] 5. Heat exchange structure; 51. Flooded shell and tube heat exchanger; 511. Regenerating tube; 512. Heat exchange tube; 513. Liquid inlet pipe; 514. Gas outlet pipe;

[0055] 52. Liquid storage tank;

[0056] 6. Vapor-liquid separator;

[0057] 7. Solenoid valve for the liquid storage tank;

[0058] 8. Compressor solenoid valve;

[0059] 9. Electronic expansion valve. Detailed Implementation

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indicators will also change accordingly.

[0061] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0062] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0063] Example 1

[0064] Please see Figure 1The present invention is a schematic diagram of the system principle, including components such as a four-way valve 1, a compressor 2, and a vapor-liquid separator 6.

[0065] One type of device for preventing liquid slugging in a heat pump system includes a four-way valve 1.

[0066] One end of the four-way valve 1 is connected to the compressor 2. A one-way valve 3 is provided in the air guide channel between the compressor 2 and the four-way valve 1. The one-way valve 3 is used to prevent refrigerant from migrating back to the compressor 2.

[0067] The other end of the four-way valve 1 is connected to a subcooling structure 4, which is connected to a heat exchange structure 5. When the heat pump system is in cooling and defrosting mode, the subcooling structure 4 adjusts the heat flow path of the heat exchange structure 5 to increase the subcooling degree of the flooded shell and tube heat exchanger 51 and reduce the amount of liquid carried by the gas at the outlet of the flooded shell and tube heat exchanger 51.

[0068] When the heat pump system switches from heating mode to defrosting mode, the subcooling structure 4 prevents refrigerant from entering the compressor 2 by adjusting the internal air pressure balance of the heat exchange structure 5.

[0069] It is worth noting that a check valve 3 is installed between compressor 2 and four-way valve 1. Due to the function of check valve 3, refrigerant can only flow from compressor 2 outward through four-way valve 1 and cannot flow from four-way valve 1 to compressor 2. A compressor solenoid valve 8 is installed between compressor 2 and vapor-liquid separator 6. When the device is running, compressor solenoid valve 8 opens, and refrigerant flows from vapor-liquid separator 6 to compressor 2. When the device stops running, compressor solenoid valve 8 closes, and refrigerant cannot enter compressor 2. Through the cooperation between check valve 3, compressor 2 and compressor solenoid valve 8, the risk of liquid slugging in compressor 2 is reduced, and the safety of the device is improved.

[0070] Preferably, an air guide channel is connected between the compressor 2 and the D-connector of the four-way valve 1.

[0071] It is worth noting that the four-way valve 1 has four connecting pipes, which are connected to the external air guide channel. The specific names of the four connecting pipes are S connecting pipe, E connecting pipe, D connecting pipe and C connecting pipe.

[0072] When the four-way valve 1 is in a de-energized state, the internal structure of the four-way valve 1 changes, and the S-connector and E-connector are connected, and the D-connector and C-connector are connected.

[0073] When the four-way valve 1 is powered on, the internal structure of the four-way valve 1 changes, and the S-connector and C-connector are connected, and the D-connector and E-connector are connected.

[0074] Preferably, the end of the compressor 2 away from the four-way valve 1 is connected to a vapor-liquid separator 6. The vapor-liquid separator 6 is connected to two gas guide channels. One gas guide channel of the vapor-liquid separator 6 is connected to the compressor 2 via a compressor solenoid valve 8, and the other gas guide channel of the vapor-liquid separator 6 is connected to the S-connector of the four-way valve 1.

[0075] Preferably, the heat exchange structure 5 includes a flooded shell-and-tube heat exchanger 51 and a storage tank 52. The flooded shell-and-tube heat exchanger 51 includes a regenerating tube 511 and a heat exchange tube 512 disposed inside the tube. A liquid inlet pipe 513 is connected to one side of the heat exchange tube 512, and a gas outlet pipe 514 is connected to one side of the regenerating tube 511. The regenerating tube 511 is connected to two gas guide channels. One gas guide channel of the regenerating tube 511 is connected to the storage tank 52, and the other gas guide channel of the regenerating tube 511 is connected to the liquid inlet pipe 513. An electronic expansion valve 9 is provided on the gas guide channel connecting the regenerating tube 511 and the liquid inlet pipe 513.

[0076] Preferably, the air guide channel connected to the C-connector of the four-way valve 1 is divided into two branches. One branch is connected to the liquid storage tank 52 and is equipped with a liquid storage tank solenoid valve 7. The other branch is connected to the air outlet pipe 514 and is equipped with a shell and tube pressure sensor 42.

[0077] Preferably, the subcooling structure 4 includes a finned heat exchanger 41, which is connected to two air guide channels. One air guide channel of the finned heat exchanger 41 is connected to the E-connector of the four-way valve 1, and the other air guide channel of the finned heat exchanger 41 is connected to the liquid storage tank 52. A tank pressure sensor 43 is provided on the air guide channel connecting the finned sensor and the liquid storage tank 52.

[0078] When the unit switches from heating mode to defrosting mode, the high-pressure refrigerant in the shell and tube can enter the liquid receiver 52 through the liquid receiver solenoid valve 7, greatly reducing the amount of refrigerant entering the gas-liquid separator and quickly balancing the high and low pressures. This effectively prevents a large amount of liquid refrigerant from entering the compressor 2. Once the high and low pressures are balanced, the liquid receiver solenoid valve 7 is closed.

[0079] The opening time of the solenoid valve 7 in the liquid storage tank is short and does not affect the normal defrosting of the device.

[0080] Simultaneously, after the solenoid valve 7 of the liquid storage tank is closed, the temperature of the regenerator tube 511 rises rapidly, exchanging heat with the outlet gas of the flooded shell and tube heat exchanger 51, vaporizing the liquid refrigerant in the outlet gas. By balancing the high and low pressures and heating the outlet gas of the shell and tube, the problem of liquid slugging in the compressor 2 caused by liquid in the outlet gas of the flooded shell and tube can be effectively solved, ensuring the practicality of the device.

[0081] Preferably, the finned heat exchanger 41, the shell and tube pressure sensor 42, and the tank pressure sensor 43 together form the subcooling structure 4.

[0082] The pipe between the finned heat exchanger 41 and the electronic expansion valve 9 is connected to the heat return pipe 511. In the cooling and defrosting modes, the heat return pipe 511 exchanges heat with the outlet gas of the flooded shell and tube heat exchanger 51, which increases the subcooling and effectively reduces the amount of liquid carried by the outlet gas. Through the cooperation of the finned heat exchanger 41 and the electronic expansion valve 9, the risk of liquid slugging in the compressor 2 is reduced in the cooling and defrosting modes.

[0083] Please see Figure 2 and Figure 3 As shown, it includes a flooded shell and tube heat exchanger 51, a regenerating tube 511, a heat exchange tube 512, a liquid inlet pipe 513, and an exhaust pipe 514.

[0084] The heat exchange structure 5 includes a flooded shell-and-tube heat exchanger 51 and a storage tank 52. The flooded shell-and-tube heat exchanger 51 includes a regenerating tube 511 and a heat exchange tube 512 disposed inside the tube. A liquid inlet pipe 513 is connected to one side of the heat exchange tube 512, and a gas outlet pipe 514 is connected to one side of the regenerating tube 511. The regenerating tube 511 is connected to two gas guide channels. One gas guide channel of the regenerating tube 511 is connected to the storage tank 52, and the other gas guide channel of the regenerating tube 511 is connected to the liquid inlet pipe 513. An electronic expansion valve 9 is provided on the gas guide channel connecting the regenerating tube 511 and the liquid inlet pipe 513.

[0085] It is worth noting that the refrigerant flows inside the shell and tubes of the flooded shell and tube heat exchanger 51, the refrigerant flows inside the heat recovery tube 511, and the water flows inside the remaining heat exchange tubes 512.

[0086] Example 2

[0087] Please see Figure 4 The diagram shown is a working logic diagram of the present invention, which includes a control method for a device for preventing liquid slugging in a heat pump system.

[0088] The method includes:

[0089] The four-way valve 1 has two working states: "0" and "non-0". The "0" state is the de-energized state, and the "non-0" state is the energized state.

[0090] The pressure value inside the liquid storage tank 52 is monitored using the tank pressure sensor 43.

[0091] The pressure value inside the outlet pipe 514 is monitored using the shell-and-tube pressure sensor 42.

[0092] Preferably, when the compressor 2 is turned on, the compressor solenoid valve 8 is turned on accordingly, thereby determining the state of the four-way valve 1;

[0093] When the compressor 2 is turned off, the compressor solenoid valve 8 is also turned off, and the liquid storage tank solenoid valve 7 is also turned off.

[0094] Preferably, when the four-way valve 1 is in the "0" working state, that is, the power is off, the values ​​of the tank pressure sensor 43 and the shell and tube pressure sensor 42 are compared.

[0095] If the value of the shell and tube pressure sensor 42 is greater than the value of the tank pressure sensor 43, then the storage tank solenoid valve 7 is opened.

[0096] If the value of the shell and tube pressure sensor 42 is less than the value of the tank pressure sensor 43, then the storage tank solenoid valve 7 is closed.

[0097] When the four-way valve 1 is in a "non-zero" working state, that is, when it is powered on, the solenoid valve 7 of the liquid storage tank is closed.

[0098] When the device is running, the compressor solenoid valve 8 opens, and the refrigerant flows from the vapor-liquid separator 6 to the compressor 2. When the device stops running, the compressor solenoid valve 8 closes, and the refrigerant cannot enter the compressor 2.

[0099] A control method for a heat pump system-based anti-liquid hammer device requires a compatible device.

[0100] The specific device is a liquid slugging prevention device for a heat pump system, including a four-way valve 1.

[0101] One end of the four-way valve 1 is connected to the compressor 2. A one-way valve 3 is provided in the air guide channel between the compressor 2 and the four-way valve 1. The one-way valve 3 is used to prevent refrigerant from migrating back to the compressor 2.

[0102] The other end of the four-way valve 1 is connected to a subcooling structure 4, which is connected to a heat exchange structure 5. When the heat pump system is in cooling and defrosting mode, the subcooling structure 4 adjusts the heat flow path of the heat exchange structure 5 to increase the subcooling degree of the flooded shell and tube heat exchanger 51 and reduce the amount of liquid carried by the gas at the outlet of the flooded shell and tube heat exchanger 51.

[0103] When the heat pump system switches from heating mode to defrosting mode, the subcooling structure 4 prevents refrigerant from entering the compressor 2 by adjusting the internal air pressure balance of the heat exchange structure 5.

[0104] It is worth noting that a check valve 3 is installed between compressor 2 and four-way valve 1. Due to the function of check valve 3, refrigerant can only flow from compressor 2 outward through four-way valve 1 and cannot flow from four-way valve 1 to compressor 2. A compressor solenoid valve 8 is installed between compressor 2 and vapor-liquid separator 6. When the device is running, compressor solenoid valve 8 opens, and refrigerant flows from vapor-liquid separator 6 to compressor 2. When the device stops running, compressor solenoid valve 8 closes, and refrigerant cannot enter compressor 2. Through the cooperation between check valve 3, compressor 2 and compressor solenoid valve 8, the risk of liquid slugging in compressor 2 is reduced, and the safety of the device is improved.

[0105] Preferably, an air guide channel is connected between the compressor 2 and the D-connector of the four-way valve 1.

[0106] When the four-way valve 1 is in a de-energized state, the internal structure of the four-way valve 1 changes, and the S-connector and E-connector are connected, and the D-connector and C-connector are connected.

[0107] When the four-way valve 1 is powered on, the internal structure of the four-way valve 1 changes, and the S-connector and C-connector are connected, and the D-connector and E-connector are connected.

[0108] Preferably, the end of the compressor 2 away from the four-way valve 1 is connected to a vapor-liquid separator 6. The vapor-liquid separator 6 is connected to two gas guide channels. One gas guide channel of the vapor-liquid separator 6 is connected to the compressor 2 via a compressor solenoid valve 8, and the other gas guide channel of the vapor-liquid separator 6 is connected to the S-connector of the four-way valve 1.

[0109] Preferably, the heat exchange structure 5 includes a flooded shell-and-tube heat exchanger 51 and a storage tank 52. The flooded shell-and-tube heat exchanger 51 includes a regenerating tube 511 and a heat exchange tube 512 disposed inside the tube. A liquid inlet pipe 513 is connected to one side of the heat exchange tube 512, and a gas outlet pipe 514 is connected to one side of the regenerating tube 511. The regenerating tube 511 is connected to two gas guide channels. One gas guide channel of the regenerating tube 511 is connected to the storage tank 52, and the other gas guide channel of the regenerating tube 511 is connected to the liquid inlet pipe 513. An electronic expansion valve 9 is provided on the gas guide channel connecting the regenerating tube 511 and the liquid inlet pipe 513.

[0110] Preferably, the air guide channel connected to the C-connector of the four-way valve 1 is divided into two branches. One branch is connected to the liquid storage tank 52 and is equipped with a liquid storage tank solenoid valve 7. The other branch is connected to the air outlet pipe 514 and is equipped with a shell and tube pressure sensor 42.

[0111] Preferably, the subcooling structure 4 includes a finned heat exchanger 41, which is connected to two air guide channels. One air guide channel of the finned heat exchanger 41 is connected to the E-connector of the four-way valve 1, and the other air guide channel of the finned heat exchanger 41 is connected to the liquid storage tank 52. A tank pressure sensor 43 is provided on the air guide channel connecting the finned sensor and the liquid storage tank 52.

[0112] When the unit switches from heating mode to defrosting mode, the high-pressure refrigerant in the shell and tube can enter the liquid receiver 52 through the liquid receiver solenoid valve 7, greatly reducing the amount of refrigerant entering the gas-liquid separator and quickly balancing the high and low pressures. This effectively prevents a large amount of liquid refrigerant from entering the compressor 2. Once the high and low pressures are balanced, the liquid receiver solenoid valve 7 is closed.

[0113] The opening time of the solenoid valve 7 in the liquid storage tank is short and does not affect the normal defrosting of the device.

[0114] Simultaneously, after the solenoid valve 7 of the liquid storage tank is closed, the temperature of the regenerator tube 511 rises rapidly, exchanging heat with the outlet gas of the flooded shell and tube heat exchanger 51, vaporizing the liquid refrigerant in the outlet gas. By balancing the high and low pressures and heating the outlet gas of the shell and tube, the problem of liquid slugging in the compressor 2 caused by liquid in the outlet gas of the flooded shell and tube can be effectively solved, ensuring the practicality of the device.

[0115] Preferably, the finned heat exchanger 41, the shell and tube pressure sensor 42, and the tank pressure sensor 43 together form the subcooling structure 4.

[0116] The pipe between the finned heat exchanger 41 and the electronic expansion valve 9 is connected to the heat return pipe 511. In the cooling and defrosting modes, the heat return pipe 511 exchanges heat with the outlet gas of the flooded shell and tube heat exchanger 51, which increases the subcooling and effectively reduces the amount of liquid carried by the outlet gas. Through the cooperation of the finned heat exchanger 41 and the electronic expansion valve 9, the risk of liquid slugging in the compressor 2 is reduced in the cooling and defrosting modes.

[0117] Example 3

[0118] An air conditioner is provided, including a device for preventing liquid slugging based on a heat pump system.

[0119] Specifically, it includes a four-way valve 1.

[0120] One end of the four-way valve 1 is connected to the compressor 2. A one-way valve 3 is provided in the air guide channel between the compressor 2 and the four-way valve 1. The one-way valve 3 is used to prevent refrigerant from migrating back to the compressor 2.

[0121] The other end of the four-way valve 1 is connected to a subcooling structure 4, which is connected to a heat exchange structure 5. When the heat pump system is in cooling and defrosting mode, the subcooling structure 4 adjusts the heat flow path of the heat exchange structure 5 to increase the subcooling degree of the flooded shell and tube heat exchanger 51 and reduce the amount of liquid carried by the gas at the outlet of the flooded shell and tube heat exchanger 51.

[0122] When the heat pump system switches from heating mode to defrosting mode, the subcooling structure 4 prevents refrigerant from entering the compressor 2 by adjusting the internal air pressure balance of the heat exchange structure 5.

[0123] It is worth noting that a check valve 3 is installed between compressor 2 and four-way valve 1. Due to the function of check valve 3, refrigerant can only flow from compressor 2 outward through four-way valve 1 and cannot flow from four-way valve 1 to compressor 2. A compressor solenoid valve 8 is installed between compressor 2 and vapor-liquid separator 6. When the device is running, compressor solenoid valve 8 opens, and refrigerant flows from vapor-liquid separator 6 to compressor 2. When the device stops running, compressor solenoid valve 8 closes, and refrigerant cannot enter compressor 2. Through the cooperation between check valve 3, compressor 2 and compressor solenoid valve 8, the risk of liquid slugging in compressor 2 is reduced, and the safety of the device is improved.

[0124] Preferably, an air guide channel is connected between the compressor 2 and the D-connector of the four-way valve 1.

[0125] When the four-way valve 1 is in a de-energized state, the internal structure of the four-way valve 1 changes, and the S-connector and E-connector are connected, and the D-connector and C-connector are connected.

[0126] When the four-way valve 1 is powered on, the internal structure of the four-way valve 1 changes, and the S-connector and C-connector are connected, and the D-connector and E-connector are connected.

[0127] Preferably, the end of the compressor 2 away from the four-way valve 1 is connected to a vapor-liquid separator 6. The vapor-liquid separator 6 is connected to two gas guide channels. One gas guide channel of the vapor-liquid separator 6 is connected to the compressor 2 via a compressor solenoid valve 8, and the other gas guide channel of the vapor-liquid separator 6 is connected to the S-connector of the four-way valve 1.

[0128] Preferably, the heat exchange structure 5 includes a flooded shell-and-tube heat exchanger 51 and a storage tank 52. The flooded shell-and-tube heat exchanger 51 includes a regenerating tube 511 and a heat exchange tube 512 disposed inside the tube. A liquid inlet pipe 513 is connected to one side of the heat exchange tube 512, and a gas outlet pipe 514 is connected to one side of the regenerating tube 511. The regenerating tube 511 is connected to two gas guide channels. One gas guide channel of the regenerating tube 511 is connected to the storage tank 52, and the other gas guide channel of the regenerating tube 511 is connected to the liquid inlet pipe 513. An electronic expansion valve 9 is provided on the gas guide channel connecting the regenerating tube 511 and the liquid inlet pipe 513.

[0129] Preferably, the air guide channel connected to the C-connector of the four-way valve 1 is divided into two branches. One branch is connected to the liquid storage tank 52 and is equipped with a liquid storage tank solenoid valve 7. The other branch is connected to the air outlet pipe 514 and is equipped with a shell and tube pressure sensor 42.

[0130] Preferably, the subcooling structure 4 includes a finned heat exchanger 41, which is connected to two air guide channels. One air guide channel of the finned heat exchanger 41 is connected to the E-connector of the four-way valve 1, and the other air guide channel of the finned heat exchanger 41 is connected to the liquid storage tank 52. A tank pressure sensor 43 is provided on the air guide channel connecting the finned sensor and the liquid storage tank 52.

[0131] When the unit switches from heating mode to defrosting mode, the high-pressure refrigerant in the shell and tube can enter the liquid receiver 52 through the liquid receiver solenoid valve 7, greatly reducing the amount of refrigerant entering the gas-liquid separator and quickly balancing the high and low pressures. This effectively prevents a large amount of liquid refrigerant from entering the compressor 2. Once the high and low pressures are balanced, the liquid receiver solenoid valve 7 is closed.

[0132] The opening time of the solenoid valve 7 in the liquid storage tank is short and does not affect the normal defrosting of the device.

[0133] Simultaneously, after the solenoid valve 7 of the liquid storage tank is closed, the temperature of the regenerator tube 511 rises rapidly, exchanging heat with the outlet gas of the flooded shell and tube heat exchanger 51, vaporizing the liquid refrigerant in the outlet gas. By balancing the high and low pressures and heating the outlet gas of the shell and tube, the problem of liquid slugging in the compressor 2 caused by liquid in the outlet gas of the flooded shell and tube can be effectively solved, ensuring the practicality of the device.

[0134] Preferably, the finned heat exchanger 41, the shell and tube pressure sensor 42, and the tank pressure sensor 43 together form the subcooling structure 4.

[0135] The pipe between the finned heat exchanger 41 and the electronic expansion valve 9 is connected to the heat return pipe 511. In the cooling and defrosting modes, the heat return pipe 511 exchanges heat with the outlet gas of the flooded shell and tube heat exchanger 51, which increases the subcooling and effectively reduces the amount of liquid carried by the outlet gas. Through the cooperation of the finned heat exchanger 41 and the electronic expansion valve 9, the risk of liquid slugging in the compressor 2 is reduced in the cooling and defrosting modes.

[0136] Each of these components is housed within the indoor and outdoor units of the air conditioner, and the compressor 2 is electrically connected to the air conditioner control panel.

[0137] An air conditioning logic control method is proposed based on an air conditioning system including a liquid slugging prevention device for the heat pump system.

[0138] Specifically, the method includes:

[0139] The four-way valve 1 has two working states: "0" and "non-0". The "0" state is the de-energized state, and the "non-0" state is the energized state.

[0140] The pressure value inside the liquid storage tank 52 is monitored using the tank pressure sensor 43.

[0141] The pressure value inside the outlet pipe 514 is monitored using the shell-and-tube pressure sensor 42.

[0142] Preferably, when the compressor 2 is turned on, the compressor solenoid valve 8 is turned on accordingly, thereby determining the state of the four-way valve 1;

[0143] When the compressor 2 is turned off, the compressor solenoid valve 8 is also turned off, and the liquid storage tank solenoid valve 7 is also turned off.

[0144] Preferably, when the four-way valve 1 is in the "0" working state, that is, the power is off, the values ​​of the tank pressure sensor 43 and the shell and tube pressure sensor 42 are compared.

[0145] If the value of the shell and tube pressure sensor 42 is greater than the value of the tank pressure sensor 43, then the storage tank solenoid valve 7 is opened.

[0146] If the value of the shell and tube pressure sensor 42 is less than the value of the tank pressure sensor 43, then the storage tank solenoid valve 7 is closed.

[0147] When the four-way valve 1 is in a "non-zero" working state, that is, when it is powered on, the solenoid valve 7 of the liquid storage tank is closed.

[0148] This method is written into the logic circuit of the air conditioner control panel. The air conditioner operates autonomously according to this method, thereby protecting the compressor 2 in the air conditioner from liquid slugging.

[0149] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A device for preventing liquid slugging in a heat pump system, comprising a four-way valve, characterized in that: A compressor is connected to one end of the four-way valve. A one-way valve is provided in the air guide passage between the compressor and the four-way valve. The one-way valve is used to prevent refrigerant from migrating back to the compressor. The other end of the four-way valve is connected to a subcooling structure, which is connected to a heat exchange structure. The heat exchange structure includes a flooded shell-and-tube heat exchanger and a liquid storage tank. The flooded shell-and-tube heat exchanger includes a regenerating tube and a heat exchange tube installed inside the tube. An inlet pipe is connected to one side of the heat exchange tube, and an outlet pipe is connected to one side of the regenerating tube. The regenerating tube is connected to two air guide channels. One air guide channel of the regenerating tube is connected to the liquid storage tank, and the other air guide channel of the regenerating tube is connected to the inlet pipe. An electronic expansion valve is installed on the air guide channel connecting the regenerating tube and the inlet pipe. The air passage connected to the four-way valve is divided into two branches. One branch is connected to the liquid storage tank and is equipped with a liquid storage tank solenoid valve. The other branch is connected to the air outlet pipe and is equipped with a shell and tube pressure sensor. When the heat pump system is in cooling and defrosting mode, the subcooling structure increases the subcooling degree of the flooded shell and tube heat exchanger and reduces the amount of liquid carried over the gas at the outlet of the flooded shell and tube heat exchanger by adjusting the heat flow path of the heat exchange structure. When the heat pump system switches from heating mode to defrosting mode, the subcooling structure prevents refrigerant from entering the compressor by adjusting the internal pressure balance of the heat exchange structure.

2. The device for preventing liquid slugging in a heat pump system according to claim 1, characterized in that, An air guide passage connects the compressor and the D-connector of the four-way valve.

3. The device for preventing liquid slugging in a heat pump system according to claim 2, characterized in that, When the four-way valve is in a de-energized state, the internal structure of the four-way valve changes, and the S-connector and E-connector are connected, and the D-connector and C-connector are connected. When the four-way valve is powered on, the internal structure of the four-way valve changes, and the S-connector and C-connector are connected, and the D-connector and E-connector are connected.

4. The device for preventing liquid hammer in a heat pump system according to claim 2, characterized in that, The compressor is connected to a vapor-liquid separator at the end furthest from the four-way valve. The vapor-liquid separator is connected to two gas guide channels. A compressor solenoid valve is installed between one of the gas guide channels of the vapor-liquid separator and the compressor. The other gas guide channel of the vapor-liquid separator is connected to the S-connector of the four-way valve.

5. The device for preventing liquid hammer in a heat pump system according to claim 4, characterized in that, The subcooling structure includes a finned heat exchanger, which is connected to two air guide channels. One of the air guide channels of the finned heat exchanger is connected to the E-connector of the four-way valve, and the other air guide channel of the finned heat exchanger is connected to the liquid storage tank. A tank pressure sensor is installed on the air guide channel connecting the finned sensor and the liquid storage tank.

6. The device for preventing liquid hammer in a heat pump system according to claim 5, characterized in that, The finned heat exchanger, the shell and tube pressure sensor, and the tank pressure sensor together form a subcooling structure.

7. A control method for a heat pump system anti-liquid slugging device, used to control the heat pump system anti-liquid slugging device as described in claim 6, characterized in that, The method includes: The pressure inside the liquid storage tank is monitored using the tank pressure sensor, and the pressure inside the vent pipe is monitored using the shell and tube pressure sensor. When the compressor is turned on, the compressor solenoid valve opens accordingly. The state of the four-way valve is then determined based on whether the four-way valve is energized. The working state of the four-way valve is divided into a de-energized state and an energized state. When the four-way valve is de-energized, compare the values ​​of the tank pressure sensor and the shell and tube pressure sensor. If the value of the shell-and-tube pressure sensor is greater than the value of the tank pressure sensor, then the storage tank solenoid valve is opened. If the value of the shell-and-tube pressure sensor is less than the value of the tank pressure sensor, then the storage tank solenoid valve is closed. When the four-way valve is energized, the liquid storage tank solenoid valve is closed; or, when the compressor is turned off, the compressor solenoid valve closes, and the liquid storage tank solenoid valve closes as well.

8. An air conditioner comprising a device for preventing liquid slugging in a heat pump system according to claim 1, characterized in that, The air conditioner is equipped with a device for preventing liquid slugging in the heat pump system as described in claim 1.

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