Air-cooled multi-split air conditioning system

Abstract

The utility model provides an air-cooled multi-split air conditioner system. The air-cooled multi-split air conditioning system comprises an indoor heat exchanger, a supercooling pipe and a pipeline switching device, and under the condition that the air-cooled multi-split air conditioning system operates in a heating mode, the indoor heat exchanger is configured to condense and liquefy a gaseous refrigerant so as to release heat; the pipeline switching device is configured to be switched to a first state under the condition that the operation parameters of the air-cooled multi-split air-conditioning system meet a first preset condition, so that a refrigerant which flows out of the indoor heat exchanger and is in a gas-liquid mixed state flows into the supercooling pipe; the supercooling pipe is configured to conduct heat exchange on the refrigerant in the gas-liquid mixed state flowing out of the indoor heat exchanger so that the gaseous refrigerant can be further liquefied. According to the air-cooled multi-split air conditioner system, the refrigerant circulation amount of the system can be increased by arranging the supercooling pipe, especially the refrigerant circulation amount under the low-temperature heating condition, and the overall energy efficiency of the system is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of air conditioning, in particular to an air-cooled multi-connected system. Background Art

[0002] With the development of society and the continuous improvement of people's living standards, various air conditioning devices have become one of the indispensable electrical equipment in people's daily lives. Various air conditioning devices can help people reach a temperature and humidity that they can adapt to when the ambient temperature and humidity are too high or too low. Current air conditioning devices mainly include various types of air conditioners and fans.

[0003] Among them, the air-cooled multi-split system consists of an outdoor unit and multiple indoor units in parallel. When the air-cooled multi-split system operates in cooling mode, the outdoor heat exchanger serves as the system's condenser, and the indoor heat exchanger serves as the system's evaporator. Through the indoor unit's supply and return air circulation, it provides cooling to the indoor environment, lowering the indoor environment's temperature and making the user feel cool. When the air-cooled multi-split system operates in heating mode, the outdoor heat exchanger serves as the system's evaporator, and the indoor heat exchanger serves as the system's condenser. Through the indoor unit's supply and return air circulation, it provides heat to the indoor environment, raising the indoor environment's temperature and making the user feel warm.

[0004] The air-cooled multi-split system can meet the needs of controlling multiple rooms separately, and the system can be flexibly interconnected, and its application is becoming more and more extensive. However, the current air-cooled multi-split system has the following problems: insufficient refrigerant during operation will cause the cooling and heating effects to deteriorate. Especially for low-temperature heating, the outdoor evaporation conditions are limited, causing most of the refrigerant to accumulate at the bottom of the gas-liquid separator, resulting in insufficient overall refrigerant circulation and poor heating effect of the whole machine.

[0005] In order to increase the refrigerant circulation volume under low-temperature heating conditions, the current air-cooled multi-split system generally uses a jet reheat compressor or adds a heating belt at the bottom of the gas-liquid separator. However, the use of a jet reheat compressor will greatly increase the operating cost and maintenance costs, consume a lot of energy, and generate relatively loud noise, which will not only affect the health of the operators, but also cause certain noise pollution to the environment. Although adding a heating belt at the bottom of the gas-liquid separator can increase the temperature of the liquid refrigerant and increase the overall refrigerant circulation volume, it will increase the power consumption and cause energy waste. Utility Model Content

[0006] One purpose of the utility model is to increase the circulation amount of refrigerant in low-temperature heating conditions by arranging a supercooling pipe, thereby improving the overall energy efficiency of the system.

[0007] A further purpose of the utility model is to use the heat that should be emitted to preheat the bottom of the gas-liquid separator, effectively saving energy and reducing operating costs.

[0008] In particular, the utility model provides an air-cooled multi-split system, comprising: an indoor heat exchanger, a subcooling pipe and a pipeline switching device, and when the air-cooled multi-split system operates in a heating mode, the indoor heat exchanger is configured to: condense and liquefy the gaseous refrigerant to release heat; the pipeline switching device is configured to: switch to a first state when the operating parameters of the air-cooled multi-split system meet a first preset condition, so that the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger flows into the subcooling pipe; the subcooling pipe is configured to: exchange heat with the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger, so that the gaseous refrigerant is further liquefied.

[0009] Optionally, the air-cooled multi-split system also includes: an outdoor heat exchanger, configured to vaporize liquid refrigerant to absorb heat from the outdoor environment; and a gas-liquid separator, connected to the outdoor heat exchanger and configured to separate the refrigerant flowing out of the outdoor heat exchanger into gas and liquid, and a supercooling pipe is arranged at the bottom of the gas-liquid separator.

[0010] Optionally, the air-cooled multi-split system also includes: an indoor throttling device, connected to the indoor heat exchanger, configured to adjust the flow of the refrigerant and fully open. When the pipeline switching device is switched to the first state, the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger flows through the indoor throttling device and then flows into the subcooling pipe.

[0011] Optionally, the air-cooled multi-split system also includes: an outdoor throttling device, connected to the outdoor heat exchanger, configured to adjust the flow of the refrigerant and partially open. When the pipeline switching device is switched to the first state, the refrigerant that has undergone heat exchange in the subcooling pipe flows through the outdoor throttling device and then flows into the outdoor heat exchanger.

[0012] Optionally, the pipeline switching device is also configured to switch to a second state when the operating parameters of the air-cooled multi-split system do not meet the first preset conditions, so that the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger flows through the indoor throttling device and then flows into the outdoor throttling device.

[0013] Optionally, the pipeline switching device includes: a first solenoid valve and a second solenoid valve, and the first solenoid valve is arranged between the supercooling pipe and the outdoor throttling device, and the second solenoid valve is arranged between the indoor throttling device and the outdoor throttling device.

[0014] Optionally, the pipeline switching device is further configured to: when switching to the first state, the first solenoid valve is opened and the second solenoid valve is closed; when switching to the second state, the first solenoid valve is closed and the second solenoid valve is opened.

[0015] Optionally, the air-cooled multi-split system also includes: a compressor configured to pressurize the gas refrigerant to make it a high-temperature and high-pressure gas; and an oil separator configured to separate the lubricating oil in the high-temperature and high-pressure gas refrigerant discharged from the compressor.

[0016] Optionally, the air-cooled multi-split system also includes: an air pipe stop valve connected to the indoor heat exchanger; a liquid pipe stop valve connected to the indoor throttling device; and a four-way valve configured to controllably connect the oil separator and the air pipe stop valve, or to connect the outdoor heat exchanger and the gas-liquid separator.

[0017] Optionally, when the pipeline switching device is switched to the first state, the refrigerant flows in sequence through the compressor, oil separator, four-way valve, gas pipe stop valve, indoor heat exchanger, indoor throttling device, liquid pipe stop valve, subcooling pipe, first solenoid valve, outdoor throttling device, outdoor heat exchanger, four-way valve, gas-liquid separator, and compressor.

[0018] Optionally, when the pipeline switching device is switched to the second state, the refrigerant flows in sequence through the compressor, oil separator, four-way valve, gas pipe stop valve, indoor heat exchanger, indoor throttling device, liquid pipe stop valve, second solenoid valve, outdoor throttling device, outdoor heat exchanger, four-way valve, gas-liquid separator, and compressor.

[0019] Optionally, the first preset condition is: the outdoor ambient temperature of the air-cooled multi-split system is less than or equal to a first preset temperature, the low pressure at the suction port of the compressor is continuously lower than the first preset pressure for more than a first preset time, the exhaust temperature is greater than or equal to a second preset temperature, and the difference between the air inlet pipe temperature and the liquid inlet pipe temperature of the indoor unit is greater than or equal to a third preset temperature.

[0020] Optionally, the second preset condition for the pipeline switching device to switch from the first state to the second state is: the outdoor ambient temperature is greater than or equal to a fourth preset temperature, the low pressure is continuously higher than the second preset pressure for more than a second preset time, and the difference between the intake pipe temperature and the liquid inlet pipe temperature is less than or equal to the fifth preset temperature.

[0021] Optionally, both the indoor throttling device and the outdoor throttling device are electronic expansion valves.

[0022] The utility model discloses an air-cooled multi-split system, comprising: an indoor heat exchanger, a subcooling pipe and a pipe switching device, and when the air-cooled multi-split system operates in a heating mode, the indoor heat exchanger is configured to: condense and liquefy the gaseous refrigerant to release heat; the pipe switching device is configured to: switch to a first state when the operating parameters of the air-cooled multi-split system meet a first preset condition, so that the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger flows into the subcooling pipe; the subcooling pipe is configured to: perform heat exchange on the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger, so that the gaseous refrigerant is further liquefied. By arranging the subcooling pipe, the refrigerant circulation volume of the system can be increased, especially the refrigerant circulation volume in the low-temperature heating condition can be increased, and the overall energy efficiency of the system can be effectively improved.

[0023] Furthermore, in the air-cooled multi-split system of the utility model, when the pipeline switching device is switched to the first state, the refrigerant flows through the compressor, oil separator, four-way valve, gas pipe stop valve, indoor heat exchanger, indoor throttling device, liquid pipe stop valve, subcooling pipe, first solenoid valve, outdoor throttling device, outdoor heat exchanger, four-way valve, gas-liquid separator, and compressor in sequence, and can use the heat that should have been dissipated to preheat the bottom of the gas-liquid separator, effectively saving energy, avoiding additional replacement, addition of equipment or consumption of electricity, and greatly reducing operating costs.

[0024] Based on the detailed description of the specific embodiments of the present invention in combination with the accompanying drawings below, those skilled in the art will become more aware of the above and other purposes, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0026] Figure 1 It is a connection diagram of an air-cooled multi-split system according to an embodiment of the utility model. DETAILED DESCRIPTION

[0027] This embodiment provides an air-cooled multi-split system. By setting a supercooling pipe, the refrigerant circulation volume of the system can be increased, especially the refrigerant circulation volume under low-temperature heating conditions, thereby effectively improving the overall energy efficiency of the system. Figure 1 FIG. 1 is a connection diagram of an air-cooled multi-split system 100 according to an embodiment of the present invention. Figure 1 As shown, the air-cooled multi-split system 100 of this embodiment may generally include: an indoor heat exchanger 106, a subcooling pipe 113 and a pipe switching device.

[0028] Wherein, when the air-cooled multi-split system 100 operates in the heating mode, the indoor heat exchanger 106 can be configured to condense and liquefy the gaseous refrigerant to release heat. The pipeline switching device can be configured to switch to the first state when the operating parameters of the air-cooled multi-split system 100 meet the first preset condition, so that the refrigerant in the gas-liquid mixed state flowing out of the indoor heat exchanger 106 flows into the supercooling pipe 113. The supercooling pipe 113 can be configured to perform heat exchange on the refrigerant in the gas-liquid mixed state flowing out of the indoor heat exchanger 106, so that the gaseous refrigerant is further liquefied.

[0029] That is, when the air-cooled multi-split system is running in heating mode, the indoor heat exchanger 106, as the condenser of the system, can condense and liquefy the gaseous refrigerant to release heat, increase the temperature of the indoor environment, and make the user feel warm. However, the indoor heat exchanger 106 may not fully condense and liquefy the refrigerant, and the refrigerant flowing out of the indoor heat exchanger 106 may be a gas-liquid mixed state.

[0030] If the operating parameters of the air-cooled multi-split system 100 meet the first preset condition, it can be switched to the first state through the pipeline switching device, so that the refrigerant in the gas-liquid mixed state flowing out of the indoor heat exchanger 106 flows into the subcooling pipe 113, and the refrigerant in the gas-liquid mixed state flowing out of the indoor heat exchanger 106 is heat exchanged by the subcooling pipe 113, so that the gas refrigerant can be further liquefied, and the refrigerant can flow to the next component in a liquid form as much as possible. In this way, the refrigerant circulation volume of the system can be increased, and the overall energy efficiency of the system can be effectively improved. Among them, the first preset condition can be a situation that meets the low-temperature heating situation, that is, the air-cooled multi-split system 100 of this embodiment can especially increase the refrigerant circulation volume under the low-temperature heating situation.

[0031] In a specific embodiment, Figure 1 As shown, the air-cooled multi-split system 100 may also include: an outdoor heat exchanger 112 and a gas-liquid separator 117. Among them, the outdoor heat exchanger 112 can be configured to vaporize the liquid refrigerant to absorb the heat of the outdoor environment. The gas-liquid separator 117 can be connected to the outdoor heat exchanger 112 and configured to separate the refrigerant flowing out of the outdoor heat exchanger 112 into gas and liquid. In addition, the subcooling pipe 113 is arranged at the bottom of the gas-liquid separator 117. The subcooling pipe 113 is arranged at the bottom of the gas-liquid separator 117, so that the refrigerant further liquefied by the subcooling pipe 113 can flow into the outdoor heat exchanger 112 as soon as possible, avoiding premature evaporation and affecting the refrigerant circulation volume of the whole machine.

[0032] As mentioned above, the current air-cooled multi-split system has the following problems: insufficient refrigerant during operation will cause poor cooling and heating effects. Especially for low-temperature heating, the outdoor evaporation conditions are limited, causing most of the refrigerant to accumulate at the bottom of the gas-liquid separator, resulting in insufficient overall refrigerant circulation and poor heating effect of the whole machine.

[0033] In order to increase the refrigerant circulation volume under low-temperature heating conditions, the current air-cooled multi-split system generally uses a jet reheat compressor or adds a heating belt at the bottom of the gas-liquid separator. However, the use of a jet reheat compressor will greatly increase the operating cost and maintenance costs, consume a lot of energy, and generate relatively loud noise, which will not only affect the health of the operators, but also cause certain noise pollution to the environment. Although adding a heating belt at the bottom of the gas-liquid separator can increase the temperature of the liquid refrigerant and increase the overall refrigerant circulation volume, it will increase the power consumption and cause energy waste.

[0034] The air-cooled multi-split system of this embodiment can increase the refrigerant circulation volume of the system, especially the refrigerant circulation volume under low-temperature heating conditions, by providing a subcooling pipe 113 at the bottom of the gas-liquid separator 117. In addition, the heat that should have been emitted can be used to preheat the bottom of the gas-liquid separator 117, effectively saving energy, avoiding additional replacement, adding equipment or consuming electricity, and greatly reducing operating costs.

[0035] like Figure 1 As shown, the air-cooled multi-split system 100 may further include: an indoor throttling device 107, connected to the indoor heat exchanger 106, configured to adjust the flow of the refrigerant and fully open. In addition, when the pipeline switching device is switched to the first state, the refrigerant in the gas-liquid mixed state flowing out of the indoor heat exchanger 106 flows through the indoor throttling device 107 and then flows into the supercooling pipe 113.

[0036] The air-cooled multi-split system 100 may further include: an outdoor throttling device 114, connected to the outdoor heat exchanger 112, configured to adjust the flow of the refrigerant and partially open. In addition, when the pipeline switching device is switched to the first state, the refrigerant that has exchanged heat through the subcooling pipe 113 flows through the outdoor throttling device 114 and then flows into the outdoor heat exchanger 112.

[0037] That is, when the air-cooled multi-split system 100 operates in the heating mode, the indoor throttling device 107 is fully opened, and the outdoor throttling device 114 is partially opened. When the air-cooled multi-split system 100 operates in the cooling mode, the opposite is true, that is, the indoor throttling device 107 is partially opened, and the outdoor throttling device 114 is fully opened. Both the indoor throttling device 107 and the outdoor throttling device 114 can play the role of throttling and reducing pressure.

[0038] In a preferred embodiment, both the indoor throttling device 107 and the outdoor throttling device 114 are electronic expansion valves. As an electronic regulating valve, the electronic expansion valve achieves the effect of throttling and reducing pressure by controlling the flow rate of the refrigerant. The working principle of the electronic expansion valve is to control the switch of the magnetic valve through an electronic signal, thereby changing the aperture size of the expansion valve to achieve flow control of the refrigerant.

[0039] By controlling the flow of the refrigerant through the electronic expansion valve, the air-cooled multi-split system 100 can be operated in a more efficient manner. Compared with the traditional mechanical expansion valve, the electronic expansion valve has higher accuracy in controlling the flow of the refrigerant; faster response speed; and more energy-saving because it can achieve more precise flow control, thereby achieving higher energy consumption efficiency.

[0040] In a specific embodiment, the pipeline switching device can also be configured to: switch to the second state when the operating parameters of the air-cooled multi-split system 100 do not meet the first preset conditions, so that the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger 106 flows through the indoor throttling device 107 and then flows into the outdoor throttling device 114.

[0041] As mentioned above, the first preset condition may be a low-temperature heating condition. If the operating parameters of the air-cooled multi-split system 100 do not meet the first preset condition, it can be considered as a normal heating condition, not a low-temperature heating condition. In the normal heating condition, the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger 106 flows through the indoor throttling device 107 and then flows into the outdoor throttling device 114.

[0042] In the case of low-temperature heating, the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger 106 flows through the indoor throttling device 107 and then flows into the subcooling pipe 113. The refrigerant after heat exchange in the subcooling pipe 113 then flows into the outdoor throttling device 114. Whether the refrigerant flowing out of the indoor throttling device 107 flows directly into the outdoor throttling device 114 or flows through the subcooling pipe 113 for heat exchange before flowing into the outdoor throttling device 114 is the main difference between normal heating and low-temperature heating.

[0043] like Figure 1As shown, the pipeline switching device may include: a first solenoid valve 110 and a second solenoid valve 119. In addition, the first solenoid valve 110 is arranged between the subcooling pipe 113 and the outdoor throttling device 114, and the second solenoid valve 119 is arranged between the indoor throttling device 107 and the outdoor throttling device 114. The pipeline switching device can also be configured as follows: when switching to the first state, the first solenoid valve 110 is opened and the second solenoid valve 119 is closed; when switching to the second state, the first solenoid valve 110 is closed and the second solenoid valve 119 is opened. When the solenoid valve is opened, the pipeline where it is located is connected; when the solenoid valve is closed, the pipeline where it is located is disconnected. The opening and closing states of the first solenoid valve 110 and the second solenoid valve 119 cooperate with each other, so that the flow path of the refrigerant is different when the pipeline switching device is in the first state and the second state.

[0044] like Figure 1 As shown, the air-cooled multi-split system 100 may further include: a compressor 101 and an oil separator 103. The compressor 101 may be configured to pressurize the gas refrigerant to make it a high-temperature and high-pressure gas. In a preferred embodiment, the compressor 101 may be a variable frequency compressor. Compared with a compressor with a constant speed, the variable frequency compressor can continuously adjust its speed within a certain range through a specific control method, and can continuously change the output energy.

[0045] Variable frequency compressors have the following advantages: Compared with traditional constant frequency compressors, variable frequency compressors consume less energy because they can automatically adjust the compression ratio according to the actual needs of the air compressor to achieve higher efficiency, thereby reducing the energy consumption of the entire system and ultimately achieving the goal of energy conservation and emission reduction; variable frequency compressors are also more efficient, and their motor drive method can automatically adjust the speed according to actual needs to ensure that optimal efficiency can be maintained under different workloads.

[0046] Moreover, since the variable frequency compressor can automatically adjust the speed, it ensures that the machine can be in the best working condition under different workloads, thus extending the life of the compressor; in addition, since the speed of the variable frequency compressor is generally low, it can also reduce the wear and failure rate of the machine and improve the reliability of the equipment; traditional compressors will produce a lot of noise during operation, and the variable frequency compressor can reduce the noise of the compressor by automatically controlling the speed, improve the working environment and improve work efficiency.

[0047] The oil separator 103 can be configured to separate the lubricating oil in the refrigerant of the high-temperature and high-pressure gas discharged from the compressor 101. Generally, the oil separator 103 can separate the oil particles in the high-pressure steam under the action of gravity according to the oil separation principle of reducing the air flow speed and changing the air flow direction. The oil separator 103 separates the lubricating oil in the refrigerant, which can ensure the safe and efficient operation of the system.

[0048] like Figure 1 As shown, the air-cooled multi-split system 100 may further include: an air pipe stop valve 108, a liquid pipe stop valve 105 and a four-way valve 104. Among them, the air pipe stop valve 108 may be connected to the indoor heat exchanger 106. The liquid pipe stop valve 105 may be connected to the indoor throttling device 107. The four-way valve 104 may be configured to controllably connect the oil separator 103 and the air pipe stop valve 108, or to connect the outdoor heat exchanger 112 and the gas-liquid separator 117. Specifically, when the refrigerant flows out of the compressor 101, the four-way valve 104 may connect the oil separator 103 and the air pipe stop valve 108. When the refrigerant is to flow back to the compressor 101, the four-way valve 104 may connect the outdoor heat exchanger 112 and the gas-liquid separator 117.

[0049] Regardless of whether the pipeline switching device is in the first state or the second state, when the refrigerant finally flows back to the compressor 101, it first passes through the gas-liquid separator 117, and is separated into gas and liquid through the gas-liquid separator 117, and the gaseous refrigerant flows into the compressor 101. The gas-liquid separator 117 can be regarded as a device for protecting the compressor 101 in the suction process, which can separate the gas and liquid of the refrigerant, prevent the low-pressure and low-temperature wet vapor returning to the compressor 101 from carrying too many droplets, and avoid liquid refrigerant from entering the compressor 101 and causing liquid hammer failure.

[0050] It should be emphasized that when the pipeline switching device is switched to the first state, the refrigerant flows sequentially through the compressor 101, the oil separator 103, the four-way valve 104, the gas pipe stop valve 108, the indoor heat exchanger 106, the indoor throttling device 107, the liquid pipe stop valve 105, the subcooling pipe 113, the first solenoid valve 110, the outdoor throttling device 114, the outdoor heat exchanger 112, the four-way valve 104, the gas-liquid separator 117, and the compressor 101. That is, in the case of low-temperature heating, the refrigerant flows according to the above path.

[0051] When the pipeline switching device is switched to the second state, the refrigerant flows sequentially through the compressor 101, the oil separator 103, the four-way valve 104, the gas pipe stop valve 108, the indoor heat exchanger 106, the indoor throttling device 107, the liquid pipe stop valve 105, the second solenoid valve 119, the outdoor throttling device 114, the outdoor heat exchanger 112, the four-way valve 104, the gas-liquid separator 117, and the compressor 101. That is, in the case of normal heating, the refrigerant flows according to the above path.

[0052] As for whether it is normal heating or low-temperature heating, the key to judgment lies in whether the operating parameters of the air-cooled multi-split system 100 meet the first preset condition. In a specific embodiment, the first preset condition can be: the outdoor ambient temperature of the air-cooled multi-split system 100 is less than or equal to the first preset temperature, the low pressure at the suction port of the compressor 101 is continuously lower than the first preset pressure for more than the first preset time, the exhaust temperature is greater than or equal to the second preset temperature, and the difference between the air inlet pipe temperature and the liquid inlet pipe temperature of the indoor unit is greater than or equal to the third preset temperature. In other words, when all of the above conditions are met, it can be considered that the first preset condition is met. As long as one of them is not met, it can be considered that the first preset condition is not met.

[0053] In a specific embodiment, the first preset temperature may be -5°C, the first preset pressure may be 3 Bar, the first preset time may be 30 minutes, the second preset temperature may be 80°C, and the third preset temperature may be 40°C. It should be noted that the specific values ​​of the above preset parameters are only for example, and are not intended to limit the present invention. In some other embodiments, other values ​​may be set according to actual conditions, but they need to generally reflect the current low-temperature heating situation.

[0054] In a preferred embodiment, Figure 1 As shown, a low pressure sensor 118 may be provided at the air inlet of the compressor 101, configured to detect the low pressure at the air inlet of the compressor 101, and may record the duration for which the low pressure is continuously lower than the first preset pressure. In addition, an external temperature sensor may be provided at the outdoor unit of the air-cooled multi-split system 100 to detect the outdoor ambient temperature. An exhaust temperature sensor may be provided at the top of the compressor 101 to detect the exhaust temperature. An intake air temperature sensor and an intake liquid temperature sensor may be provided at the intake pipe and the liquid inlet pipe of the indoor unit, respectively, to detect the intake pipe temperature and the liquid inlet pipe temperature, respectively.

[0055] In a preferred embodiment, after receiving a trigger signal for starting the heating mode, the air-cooled multi-split system 100 can first control the pipeline switching device to switch to the second state, so that the refrigerant in the gas-liquid mixed state flowing out of the indoor heat exchanger 106 flows through the indoor throttling device 107 and then flows into the outdoor throttling device 114. That is, the air-cooled multi-split system 100 can be controlled to work according to the normal heating situation. In addition, a defrosting process can be completed when the air-cooled multi-split system 100 meets the defrosting conditions, and then the operating parameters of the air-cooled multi-split system 100 are detected to determine whether the operating parameters of the air-cooled multi-split system 100 meet the first preset conditions, that is, to determine whether the current situation belongs to the low-temperature heating situation.

[0056] If the operating parameters meet the first preset condition, the current situation is low-temperature heating, and the pipeline switching device can be controlled to switch from the second state to the first state, so that the refrigerant in the gas-liquid mixed state flowing out of the indoor heat exchanger 106 flows into the supercooling pipe 113, and the refrigerant is heat-exchanged by the supercooling pipe 113, so that the gas refrigerant is further liquefied. If the operating parameters do not meet the first preset condition, the pipeline switching device is controlled to remain in the second state.

[0057] However, once the pipeline switching device is switched to the first state, in order to exit the state, that is, to switch to the second state, the operating parameters need to meet the second preset condition. Specifically, the second preset condition for the pipeline switching device to switch from the first state to the second state is: the outdoor ambient temperature is greater than or equal to the fourth preset temperature, the low pressure is continuously higher than the second preset pressure for more than the second preset time, and the difference between the air inlet pipe temperature and the liquid inlet pipe temperature is less than or equal to the fifth preset temperature.

[0058] In a specific embodiment, the fourth preset temperature may be 0°C, the second preset pressure may be 4 Bar, the second preset time may be 10 minutes, and the fifth preset temperature may be 30°C. It should be noted that the specific values ​​of the above preset parameters are only for example, and are not intended to limit the present invention. In some other embodiments, other values ​​may be set according to actual conditions, but they need to generally reflect that the current situation is no longer low-temperature heating.

[0059] In addition, if Figure 1 As shown, the air-cooled multi-split system 100 may also be provided with other small components, such as a high-pressure pressure sensor 102, a return air temperature sensor 109, and pipe temperature sensors 116, 120, and 121, which may be configured to detect the pressure and temperature at the respective locations. Figure 1 A return gas pipe 111 is also shown in the figure, so that the gaseous refrigerant returns to the compressor 101 after passing through the gas-liquid separator 117 .

[0060] In summary, the air-cooled multi-split system 100 of the present embodiment includes: an indoor heat exchanger 106, a subcooling pipe 113 and a pipeline switching device, and when the air-cooled multi-split system 100 operates in the heating mode, the indoor heat exchanger 106 is configured to condense and liquefy the gaseous refrigerant to release heat; the pipeline switching device is configured to switch to a first state when the operating parameters of the air-cooled multi-split system 100 meet the first preset condition, so that the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger 106 flows into the subcooling pipe 113; the subcooling pipe 113 is configured to perform heat exchange on the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger 106, so that the gaseous refrigerant is further liquefied. By setting the subcooling pipe 113, the refrigerant circulation volume of the system can be increased, especially the refrigerant circulation volume under low-temperature heating conditions, thereby effectively improving the overall energy efficiency of the system.

[0061] Furthermore, in the air-cooled multi-split system 100 of the present embodiment, when the pipeline switching device is switched to the first state, the refrigerant flows through the compressor 101, the oil separator 103, the four-way valve 104, the gas pipe stop valve 108, the indoor heat exchanger 106, the indoor throttling device 107, the liquid pipe stop valve 105, the subcooling pipe 113, the first solenoid valve 110, the outdoor throttling device 114, the outdoor heat exchanger 112, the four-way valve 104, the gas-liquid separator 117, and the compressor 101 in sequence, and can use the heat that should have been dissipated to preheat the bottom of the gas-liquid separator 117, effectively saving energy, avoiding additional replacement, addition of equipment or consumption of electricity, and greatly reducing operating costs.

[0062] In the description of this embodiment, it needs to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the utility model.

[0063] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, it is defined that the features "first", "second", etc. may explicitly or implicitly include at least one of the features, that is, include one or more of the features.

[0064] In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically limited. When a feature "includes or contains" one or some of the features it covers, unless otherwise specifically described, this indicates that other features are not excluded and other features may be further included.

[0065] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", "coupled" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. A person of ordinary skill in the art should be able to understand the specific meanings of the above terms in the present utility model according to the specific circumstances.

[0066] Furthermore, in the description of this embodiment, a first feature being “above” or “below” a second feature may include the first and second features being in direct contact with each other, or the first and second features not being in direct contact with each other but being in contact with each other via another feature therebetween.

[0067] That is, in the description of this embodiment, the first feature being "above", "above", and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below", or "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0068] Unless otherwise defined, all terms (including technical terms and scientific terms) used in the description of the embodiments of the present invention have the same meanings as those commonly understood by ordinary technicians in the technical field to which the present application belongs.

[0069] In the description of the present embodiment, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0070] At this point, those skilled in the art should recognize that, although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived from the contents disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. An air-cooled multi-connection system, characterized in that: include: Indoor heat exchanger, subcooling pipe and pipe switching device, and When the air-cooled multi-split system is running in heating mode, The indoor heat exchanger is configured to: condense and liquefy the gaseous refrigerant to release heat; The pipeline switching device is configured to: switch to a first state when the operating parameters of the air-cooled multi-split system meet a first preset condition, so that the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger flows into the supercooling pipe; The supercooling pipe is configured to perform heat exchange on the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger to further liquefy the gas refrigerant.

2. The air-cooled multi-split system according to claim 1, characterized in that: Also includes: an outdoor heat exchanger configured to vaporize liquid refrigerant to absorb heat from an outdoor environment; and A gas-liquid separator is connected to the outdoor heat exchanger and is configured to separate the refrigerant flowing out of the outdoor heat exchanger into gas and liquid, and The supercooling pipe is arranged at the bottom of the gas-liquid separator.

3. The air-cooled multi-split system according to claim 2, characterized in that: Also includes: The indoor throttling device is connected to the indoor heat exchanger and is configured to adjust the flow of the refrigerant and is fully opened. When the pipe switching device is switched to the first state, the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger flows through the indoor throttling device and then flows into the supercooling pipe.

4. The air-cooled multi-split system according to claim 3, characterized in that: Also includes: An outdoor throttling device is connected to the outdoor heat exchanger and is configured to adjust the flow of the refrigerant and is partially opened. When the pipeline switching device is switched to the first state, the refrigerant that has undergone heat exchange in the subcooling pipe flows through the outdoor throttling device and then flows into the outdoor heat exchanger.

5. The air-cooled multi-split system according to claim 4, characterized in that: The pipeline switching device is also configured to switch to the second state when the operating parameters of the air-cooled multi-split system do not meet the first preset conditions, so that the refrigerant in a gas-liquid mixed state flowing out of the indoor heat exchanger flows through the indoor throttling device and then flows into the outdoor throttling device.

6. The air-cooled multi-split system according to claim 5, characterized in that: The pipeline switching device includes: a first solenoid valve and a second solenoid valve, and The first solenoid valve is set between the subcooling pipe and the outdoor throttling device. The second solenoid valve is arranged between the indoor throttling device and the outdoor throttling device.

7. The air-cooled multi-split system according to claim 6, characterized in that: The pipeline switching device is also configured such that: when switching to the first state, the first solenoid valve is opened and the second solenoid valve is closed; when switching to the second state, the first solenoid valve is closed and the second solenoid valve is opened.

8. The air-cooled multi-split system according to claim 7, characterized in that: Also includes: A compressor configured to pressurize the gaseous refrigerant to make it a high-temperature and high-pressure gas; as well as The oil separator is configured to separate lubricating oil from the high-temperature and high-pressure gas refrigerant discharged from the compressor.

9. The air-cooled multi-split system according to claim 8, characterized in that: Also includes: Gas pipe stop valve, connected to the indoor heat exchanger; Liquid pipe stop valve, connected to the indoor throttling device; as well as The four-way valve is configured to controllably connect the oil separator and the gas pipe stop valve, or to connect the outdoor heat exchanger and the gas-liquid separator.

10. The air-cooled multi-split system according to claim 9, characterized in that: When the pipeline switching device is switched to the first state, the refrigerant flows through the compressor, oil separator, four-way valve, gas pipe stop valve, indoor heat exchanger, indoor throttling device, liquid pipe stop valve, subcooling pipe, first solenoid valve, outdoor throttling device, outdoor heat exchanger, four-way valve, gas-liquid separator, and compressor in sequence.

11. The air-cooled multi-split system according to claim 9, characterized in that: When the pipeline switching device is switched to the second state, the refrigerant flows through the compressor, oil separator, four-way valve, gas pipe stop valve, indoor heat exchanger, indoor throttling device, liquid pipe stop valve, second solenoid valve, outdoor throttling device, outdoor heat exchanger, four-way valve, gas-liquid separator, and compressor in sequence.

12. The air-cooled multi-split system according to claim 8, characterized in that: The first preset condition is: the outdoor ambient temperature of the air-cooled multi-split system is less than or equal to the first preset temperature, the low pressure at the suction port of the compressor is continuously lower than the first preset pressure for more than a first preset time, the exhaust temperature is greater than or equal to the second preset temperature, and the difference between the air inlet pipe temperature and the liquid inlet pipe temperature of the indoor unit is greater than or equal to the third preset temperature.

13. The air-cooled multi-split system according to claim 12, characterized in that: The second preset condition for the pipeline switching device to switch from the first state to the second state is: the outdoor ambient temperature is greater than or equal to the fourth preset temperature, the low pressure is continuously higher than the second preset pressure for more than the second preset time, and the difference between the intake pipe temperature and the liquid inlet pipe temperature is less than or equal to the fifth preset temperature.

14. The air-cooled multi-split system according to claim 4, characterized in that: Both the indoor throttling device and the outdoor throttling device are electronic expansion valves.

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