Air conditioner

Abstract

The utility model relates to an air conditioner, it includes indoor unit and outdoor unit, and the indoor unit includes indoor heat exchanger, and the outdoor unit includes compressor, four -way valve and outdoor heat exchanger, wherein, still be provided with defrosting heat exchanger in the outdoor unit, and the defrosting heat exchanger includes first channel and second channel, the both ends of first channel are connected with the exhaust end of compressor and the first end of outdoor heat exchanger through first branch, and the first switch valve is set up between compressor and first channel, the both ends of second channel are connected with the second end of indoor heat exchanger and the first end of outdoor heat exchanger through second branch, and the second switch valve is set up between second channel and indoor heat exchanger, this kind of defrosting mode can make indoor heat exchanger maintain heating function, and the heating continuity is high, and the comfort is good, and need not to change direction to four -way valve, be favorable to preventing compressor liquid knock, reduce system impact, significantly improve energy efficiency and prolong equipment life.

Description

Technical Field

[0001] This utility model belongs to the field of air conditioning equipment technology, and in particular relates to an air conditioner. Background Technology

[0002] Frosting of the outdoor unit during air conditioning heating is a common problem in the industry, especially in low outdoor temperatures. When the outdoor coil is at a low temperature, moisture in the air condenses on the surface of the outdoor heat exchanger, causing frost. Frost on the outdoor heat exchanger can clog the channels between the fins, affecting heat exchange and reducing heating capacity.

[0003] One traditional defrosting method involves reversing the four-way valve to defrost. During defrosting, the air conditioner stops heating and switches to cooling mode. This defrosting method causes interruption of indoor heating and temperature fluctuations, affecting comfort. Frequent switching of operating modes increases the number of compressor start-stop cycles, leading to increased system energy consumption. Starting the compressor after defrosting poses a risk of liquid slugging, and long-term operation may affect the compressor's lifespan.

[0004] In addition, some air conditioners use a portion of the high-temperature refrigerant for bypass defrosting. This bypass defrosting method has several drawbacks: insufficient defrosting heat leads to prolonged defrosting time, affecting the continuity of heating; in addition, the bypassed hot air may concentrate in a local area of ​​the evaporator, causing that area to overheat while other areas still have residual frost, reducing the defrosting effect; and the bypassed refrigerant does not fully participate in the system heat exchange, affecting the overall heating efficiency of the system. Utility Model Content

[0005] The purpose of this utility model is to provide an air conditioner that solves the problems of outdoor unit frost formation during low-temperature heating, which affects heating efficiency, poor indoor heating effect due to existing four-way valve reversing defrosting methods, and reduced equipment lifespan due to frequent switching of the four-way valve.

[0006] To achieve the above-mentioned objectives, the present invention employs the following technical solution: In one aspect, this utility model proposes an air conditioner, which includes: Indoor unit, which includes indoor heat exchanger, The outdoor unit includes a compressor, a four-way valve, and an outdoor heat exchanger. The four-way valve includes a first valve port, a second valve port, a third valve port, and a fourth valve port. The first valve port is connected to the discharge end of the compressor, the second valve port is connected to at least one first end of the indoor heat exchanger, the third valve port is connected to the suction end of the compressor, and the fourth valve port is connected to the second end of the outdoor heat exchanger. The first end of the outdoor heat exchanger is connected to the second end of the indoor heat exchanger. The outdoor unit is also equipped with a defrost heat exchanger, which includes a first channel and a second channel. The two ends of the first channel are connected to the exhaust end of the compressor and the first end of the outdoor heat exchanger via a first branch, and a first switching valve is provided between the compressor and the first channel; the two ends of the second channel are connected to the second end of the indoor heat exchanger and the first end of the outdoor heat exchanger via a second branch, and a second switching valve is provided between the second channel and the indoor heat exchanger.

[0007] In some embodiments of this application, the indoor heat exchanger includes at least one air-side heat exchanger; The air-side heat exchanger is connected to the exhaust end of the compressor via a first main line; the first end of the air-side heat exchanger is connected to the second valve port of the four-way valve; the second end of the air-side heat exchanger is connected to the first end of the outdoor heat exchanger via a second main line; a third switching valve is provided on the second main line. The outdoor unit also includes a water-side heat exchanger, which includes a refrigeration channel and a cooling channel. The two ends of the refrigeration channel are respectively connected to the exhaust end of the compressor and the end of the second channel away from the outdoor heat exchanger via a third main channel.

[0008] The air-side heat exchanger and the water-side heat exchanger are used to regulate the indoor temperature. The water-side heat exchanger can also be used to provide domestic hot water to users. During the defrosting process of the outdoor heat exchanger, when users only need the heating function, at least one of the air-side heat exchanger and the water-side heat exchanger will always remain in heating mode. When users need both heating and domestic hot water functions at the same time, the air-side heat exchanger and the water-side heat exchanger will always remain in heating mode to ensure user comfort and water demand.

[0009] In some embodiments of this application, the first channel and the exhaust end of the compressor are connected by an upstream section of a first branch, and the first channel and the outdoor heat exchanger are connected by a downstream section of the first branch; The first switching valve is installed on the upstream section of the first branch, and the first expansion valve is installed on the downstream end of the first branch.

[0010] The first switching valve is used to control the switching of the first channel. The opening of the first expansion valve is adjustable and can be adjusted according to the defrosting status of the outdoor heat exchanger, enabling precise defrosting control, improving defrosting efficiency, reducing energy consumption, and controlling suction superheat to prevent compressor liquid slugging.

[0011] In some embodiments of this application, the second channel is connected to the second main road via the upstream section of the second branch road, and the connection point between the upstream section of the second branch road and the second main road is located between the wind-side heat exchanger and the third switching valve; the second channel is connected to the outdoor heat exchanger via the downstream section of the second branch road. The second switching valve is installed on the upstream section of the second branch, and the second expansion valve is installed on the downstream section of the second branch.

[0012] The second switching valve is used to control the opening and closing of the second channel. The second expansion valve works in conjunction with the first expansion valve to regulate the amount of refrigerant passing through the first and second channels, thereby regulating the heat exchange capacity of the defrost heat exchanger, making it more controllable.

[0013] In some embodiments of this application, there are multiple air-side heat exchangers, and each air-side heat exchanger is connected in parallel between the first valve port and the defrost heat exchanger via a refrigerant auxiliary line. Each refrigerant auxiliary line is provided with a third expansion valve.

[0014] Air-side heat exchangers can be installed in the same space or different spaces according to actual design requirements.

[0015] In some embodiments of this application, the outdoor unit is further provided with components and a temperature control device. The temperature control device is connected to the outside of the components and is used to control the temperature of the components. The temperature control device is connected to the second main line and is located between the third switch valve and the outdoor heat exchanger. The downstream section of the first branch line is connected to the outdoor heat exchanger through the temperature control device.

[0016] The refrigerant flowing through the temperature control component is at a low temperature, which can be used to absorb the heat generated during the operation of the components, thereby cooling the components and improving their service life.

[0017] In some embodiments of this application, a fourth expansion valve is further provided between the temperature control element and the outdoor heat exchanger, and filters are respectively provided on both sides of the fourth expansion valve.

[0018] In some embodiments of this application, a first pressure switch is provided at the discharge end of the compressor, a second pressure switch is provided at the suction end of the compressor, and a first pressure detection element is provided between the water-side heat exchanger and the discharge end of the compressor.

[0019] In some embodiments of this application, the cooling channel is connected to the exhaust end of the compressor via the upstream section of the third main channel and to the second main channel via the downstream section of the third main channel. The connection point between the downstream section of the third main channel and the second main channel is located between the air-side heat exchanger and the third switching valve. A fifth expansion valve and a filter are also provided on the downstream section of the third main channel.

[0020] A gas-side shut-off valve is provided between the second valve port and the air-side heat exchanger, and a liquid-side shut-off valve is provided between the air-side heat exchanger and the third switching valve.

[0021] On the other hand, this application also proposes an air conditioner comprising: Indoor unit, which includes at least one indoor heat exchanger, The outdoor unit includes a compressor, a four-way valve, and an outdoor heat exchanger. Each port of the four-way valve is connected to the discharge end of the compressor, the indoor heat exchanger, the suction end of the compressor, and the outdoor heat exchanger, respectively. The compressor's exhaust end is connected to the outdoor heat exchanger via a first branch, and the indoor heat exchanger is connected to the outdoor heat exchanger via a second branch. The first and second branches exchange heat through a defrost heat exchanger to increase the refrigerant temperature in the second branch and defrost the outdoor heat exchanger.

[0022] Compared with the prior art, the advantages and positive effects of this utility model are: The air conditioner involved in this application is equipped with a defrost heat exchanger. The defrost heat exchanger has a first channel and a second channel. The first channel is connected between the discharge end of the compressor and the outdoor heat exchanger, and the second channel is located between the indoor heat exchanger and the outdoor heat exchanger. When defrosting is required, the first switch valve and the second switch valve are opened. Part of the refrigerant output by the compressor is input into the outdoor heat exchanger through the first channel, and part of the refrigerant output by the indoor heat exchanger is input into the outdoor heat exchanger through the second channel. The refrigerant in the first channel and the second channel exchanges heat in the defrost heat exchanger, raising the temperature of the refrigerant in the second channel for defrosting the outdoor heat exchanger. This defrosting method allows the indoor heat exchanger to maintain its heating function, ensuring high heating continuity and good comfort. It also eliminates the need to switch the four-way valve, which helps prevent compressor liquid slugging, reduces system shock, significantly improves energy efficiency, and extends equipment life.

[0023] Other features and advantages of this utility model will become clearer after reading the detailed embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a system diagram of one embodiment of an air conditioner according to an embodiment; Figure 2 This is a schematic diagram of the four-way valve port. Figure 3 According to Figure 1 The system diagram of the air conditioner in heating mode only; Figure 4 According to Figure 1 System diagram of the air conditioner in defrost mode; Figure 5 This is a system diagram of yet another embodiment of the air conditioner according to the embodiments; Figure 6 According to Figure 5 The system diagram of the air conditioner in heating mode only; Figure 7 According to Figure 5 System diagram of the air conditioner in defrost mode; Figure 8 This is a system diagram of another embodiment of the air conditioner according to the embodiment; Figure 9 According to Figure 8 The system diagram of the air conditioner in heating mode only; Figure 10 According to Figure 8 System diagram of the air conditioner in defrost mode; Figure 11 For the opening control table of the first and second expansion valves; Figure label: 100. Compressor; 110. First pressure switch; 120. Second pressure switch; 130. Gas-liquid separator; 140. Pressure detection element; 150. Gas-side shut-off valve; 160. Liquid-side shut-off valve; 200, Four-way valve; 210, First valve port; 220, Second valve port; 230, Third valve port; 240, Fourth valve port; 300. Indoor heat exchanger; 310. Air-side heat exchanger; 400. Outdoor heat exchanger; 410. Water-side heat exchanger; 411. Refrigeration aisle; 412. Cooling aisle; 500, Defrosting heat exchanger; 510, First channel; 520, Second channel; 610, First Main Road; 620, Second Main Road; 630, Fourth Main Road; 640. First branch road; 641. Upstream section of the first branch road; 642. Downstream section of the first branch road; 650. Second branch road; 651. Upstream section of the second branch road; 652. Downstream section of the second branch road; 661. Upstream section of the Third Main Road; 662. Downstream section of the Third Main Road; 710. First switching valve; 720. Second switching valve; 730. Third switching valve; 810. First expansion valve; 820. Second expansion valve; 830. Third expansion valve; 840. Fourth expansion valve; 850. Fifth expansion valve; 860. Filter; 900. Temperature control components. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0032] In this application, the air conditioner performs a refrigeration cycle by using a compressor, condenser, expansion valve, and evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation to cool or heat an indoor space.

[0033] Low-temperature, low-pressure refrigerant enters the compressor, which compresses it into a high-temperature, high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

[0034] The expansion valve expands the high-temperature, high-pressure liquid refrigerant that condenses in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the expanded refrigerant in the expansion valve and returns the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves its cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled. Throughout the cycle, the air conditioner regulates the temperature of the indoor space.

[0035] The outdoor unit of an air conditioner refers to the part of the refrigeration cycle that includes the compressor and the outdoor heat exchanger, while the indoor unit of an air conditioner includes the indoor heat exchanger.

[0036] The indoor and outdoor heat exchangers function as either condensers or evaporators. When the indoor heat exchanger is used as a condenser, the air conditioner functions as a heater in heating mode; when the indoor heat exchanger is used as an evaporator, the air conditioner functions as a cooler in cooling mode.

[0037] refer to Figures 1-4 In one aspect, this utility model proposes an air conditioner, which includes an indoor unit and an outdoor unit. The indoor unit includes at least one indoor heat exchanger 300, and the outdoor unit includes a compressor 100, a four-way valve 200, and an outdoor heat exchanger 400, etc.

[0038] The four-way valve 200 includes a first valve port 210, a second valve port 220, a third valve port 230, and a fourth valve port 240. The first valve port 210 is connected to the discharge end of the compressor 100, the second valve port 220 is connected to the first end of at least one indoor heat exchanger 300, the third valve port 230 is connected to the suction end of the compressor 100, and the fourth valve port 240 is connected to the second end of the outdoor heat exchanger 400. The first end of the outdoor heat exchanger 400 is connected to the second end of the indoor heat exchanger 300.

[0039] The outdoor unit is also equipped with a defrost heat exchanger 500, which is a plate heat exchanger.

[0040] The defrosting heat exchanger 500 includes a first channel 510 and a second channel 520; the first channel 510 and the second channel 520 can exchange heat with each other.

[0041] The first channel 510 is connected between the exhaust end of the compressor 100 and the first end of the outdoor heat exchanger 400.

[0042] Specifically, the two ends of the first channel 510 are connected to the exhaust end of the compressor 100 and the first end of the outdoor heat exchanger 400 through the first branch 640.

[0043] For ease of understanding and description, the first channel 510 and the exhaust end of the compressor 100 are connected by the upstream section 641 of the first branch, and the first channel 510 is connected to the first end of the outdoor heat exchanger 400 by the downstream section 642 of the first branch.

[0044] A first switching valve 710 is provided between the compressor 100 and the first channel 510 to control the connection and disconnection between the first channel 510 and the discharge end of the compressor 100.

[0045] Specifically, the first switching valve 710 is installed on the upstream section 641 of the first branch.

[0046] The second channel 520 is connected between the second end of the indoor heat exchanger 300 and the first end of the outdoor heat exchanger 400.

[0047] Specifically, the two ends of the second channel 520 are connected to the second end of the indoor heat exchanger 300 and the first end of the outdoor heat exchanger 400 through the second branch 650.

[0048] For ease of understanding and description, the first channel 510 and the second end of the indoor heat exchanger 300 are connected by the upstream section 651 of the second branch, and the second channel 520 is connected to the first end of the outdoor heat exchanger 400 by the downstream section 652 of the second branch.

[0049] A second switching valve 720 is provided between the second channel 520 and the indoor heat exchanger 300 to control the on / off connection between the indoor heat exchanger 300 and the second channel 520.

[0050] Specifically, the second switching valve 720 is installed on the upstream section 651 of the second branch.

[0051] In some embodiments of this application, the indoor heat exchanger 300 specifically includes a plurality of wind-side heat exchangers 310 connected in parallel.

[0052] Specifically, the second valve port 220 and the indoor heat exchanger 300 are connected through the first main line 610, the second end of the indoor heat exchanger 300 is connected to the first end of the outdoor heat exchanger 400 through the second main line 620, and the second end of the outdoor heat exchanger 400 is connected to the fourth valve port 240 of the four-way valve 200 through the fourth main line 630.

[0053] In some embodiments of this application, a gas-liquid separator 130 is also provided between the third valve port 230 of the four-way valve 200 and the suction end of the compressor 100.

[0054] In some other embodiments, a first expansion valve 810 is provided on the downstream section 642 of the first branch, and a second expansion valve 820 is provided on the downstream section 652 of the second branch.

[0055] A third expansion valve 830 and a fourth expansion valve 840 are provided between the indoor heat exchanger 300 and the outdoor heat exchanger 400.

[0056] The fourth expansion valve 840 is located at the first end of the outdoor heat exchanger 400.

[0057] The refrigerant output after heat exchange in the indoor heat exchanger 300, as well as the refrigerant output after heat exchange in the downstream section 642 of the first branch, are both transported to the outdoor heat exchanger 400 through the fourth expansion valve 840.

[0058] When in heating mode and defrosting conditions are not met, the controller controls the first switching valve 710 and the second switching valve 720 to open, the third switching valve 730 to close, and the first branch 640 and the second branch 650 to be in the open state.

[0059] The high-temperature and high-pressure refrigerant output by the compressor 100 is delivered to the indoor heat exchanger 300 for heat exchange after passing through the first valve port 210 and the second valve port 220. After heat exchange, the refrigerant passes through the third expansion valve 830 and then through the fourth expansion valve 840 on the second main circuit 620 to the outdoor heat exchanger 400. After heat exchange in the outdoor heat exchanger 400, it is delivered back to the suction end of the compressor 100 after passing through the fourth valve port 240 and the third valve port 230 of the four-way valve 200.

[0060] When the defrosting conditions are met, the controller controls the first switching valve 710 and the second switching valve 720 to be closed, and the third switching valve 730 to be open.

[0061] The first branch 640 and the second branch 650 are connected.

[0062] The high-temperature and high-pressure refrigerant output by the compressor 100 is partly transported to the indoor heat exchanger 300 for heat exchange after passing through the first valve port 210 and the second valve port 220, and the other part is transported to the first channel 510 through the upstream section 641 of the first branch to exchange heat with the refrigerant in the second channel 520.

[0063] The refrigerant output from the indoor heat exchanger 300 after heat exchange is transported to the second channel 520 via the upstream section 651 of the second branch. After heat exchange with the high-temperature refrigerant in the first channel 510, the temperature rises.

[0064] After heat exchange, the refrigerant in the first channel 510 passes through the first expansion valve 810 and the fourth expansion valve 840, and the refrigerant in the second channel 520 passes through the second expansion valve 820. Both are then transported to the outdoor heat exchanger 400 for heat exchange. Finally, after passing through the fourth main channel 630, they are returned to the suction end of the compressor 100.

[0065] In other words, when defrosting is required, the first switching valve 710 and the second switching valve 720 are opened. Part of the refrigerant output from the compressor 100 is input into the outdoor heat exchanger 400 through the first channel 510, and part of the refrigerant output from the indoor heat exchanger 300 is input into the outdoor heat exchanger 400 through the second channel 520. The refrigerant in the first channel 510 and the second channel 520 exchange heat in the defrosting heat exchanger 500, raising the temperature of the refrigerant in the second channel 520 for defrosting the outdoor heat exchanger 400.

[0066] Specifically, the low-temperature, low-pressure liquid refrigerant output from the indoor heat exchanger 300 is input into the second channel 520 through the upstream section 651 of the second branch, where it exchanges heat with the high-temperature, high-pressure gaseous refrigerant input into the first channel 510 through the upstream section 641 of the first branch. Then, the refrigerant heated in the second channel 520 flows to the outdoor heat exchanger 400 through the second expansion valve 820 for defrosting.

[0067] The high-temperature, high-pressure gaseous refrigerant in the first channel 510 exchanges heat with the refrigerant in the second channel 520 and becomes a low-temperature, low-pressure liquid refrigerant, which is also transported to the outdoor heat exchanger 400.

[0068] This defrosting method allows the indoor heat exchanger 300 to maintain its heating function, ensuring high heating continuity and good comfort. It also eliminates the need to switch the four-way valve 200, which helps prevent liquid slugging in the compressor 100, reduces system impact, significantly improves energy efficiency, and extends equipment life.

[0069] refer to Figures 5-7 In some other embodiments of this application, the indoor heat exchanger 300 includes at least one air-side heat exchanger 310.

[0070] The air-side heat exchanger 310 is connected to the exhaust end of the compressor 100 via the first main line 610.

[0071] The first end of the air-side heat exchanger 310 is connected to the second valve port 220 of the four-way valve 200, and the second end of the air-side heat exchanger 310 is connected to the first end of the outdoor heat exchanger 400 through the second main line 620; a third switch valve 730 is provided on the second main line 620.

[0072] The water-side heat exchanger 410 in the outdoor unit is a plate heat exchanger, which includes a refrigeration channel 411 and a cooling channel 412. The two ends of the refrigeration channel 411 are respectively connected to the exhaust end of the compressor 100 and the end of the second channel 520 away from the outdoor heat exchanger 400 through the third main channel.

[0073] The two ends of the cooling channel 412 are connected to the inlet water pipe and the outlet water pipe, respectively. The inlet water pipe delivers low-temperature water into the cooling channel 412, and the high-temperature water that has been heated by heat exchange with the cooling channel 411 is output to the water terminal through the outlet water pipe.

[0074] In some embodiments of this application, the cooling channel 412 is connected to the exhaust end of the compressor 100 via the upstream section 661 of the third main channel and to the second main channel 620 via the downstream section 662 of the third main channel. The connection point between the downstream section 662 of the third main channel and the second main channel 620 is located between the air-side heat exchanger 310 and the third switching valve 730. A fifth expansion valve 850 and a filter 860 are also provided on the downstream section 662 of the third main channel.

[0075] In other words, the refrigeration passage 411 is connected between the exhaust end of the compressor 100 and the second end of the indoor heat exchanger 300 via a third main passage.

[0076] For ease of understanding, the refrigeration aisle 411 is defined to be connected to the compressor 100 via the upstream section 661 of the third main road and to the indoor heat exchanger 300 via the downstream section 662 of the third main road.

[0077] The upstream section 641 of the first branch road and the upstream section 661 of the third main road are both connected to the fifth main road between the exhaust end of the compressor 100 and the first valve port 210.

[0078] The air-side heat exchanger 310 and the water-side heat exchanger 410 are used to regulate the indoor temperature. The water-side heat exchanger 410 can also be used to provide domestic hot water to users. During the defrosting process of the outdoor heat exchanger, when users only need the heating function, at least one of the air-side heat exchanger 310 and the water-side heat exchanger 410 will always remain in heating mode. When users need both heating and domestic hot water functions at the same time, the air-side heat exchanger 310 and the water-side heat exchanger 410 will always remain in heating mode to ensure user comfort and water demand.

[0079] In some embodiments of this application, a first switching valve 710 is disposed on the upstream section 641 of the first branch, and a first expansion valve 810 is disposed on the downstream end of the first branch 640.

[0080] The first switching valve 710 is used to control the opening and closing of the first channel 510. The opening of the first expansion valve 810 is adjustable and can be adjusted according to the defrosting status of the outdoor heat exchanger 400. This allows for precise defrosting control, improved defrosting efficiency, reduced energy consumption, and control of suction superheat to prevent liquid slugging in the compressor 100.

[0081] Similar to the previous embodiment, the second valve port 220 and the indoor heat exchanger 300 are connected by the first main line 610, the second end of the indoor heat exchanger 300 is connected to the first end of the outdoor heat exchanger 400 through the second main line 620, and the second end of the outdoor heat exchanger 400 is connected to the fourth valve port 240 of the four-way valve 200 through the fourth main line 630.

[0082] In some other embodiments, a first expansion valve 810 is provided on the downstream section 642 of the first branch, and a second expansion valve 820 is provided on the downstream section 652 of the second branch.

[0083] A third expansion valve 830 is installed between the indoor heat exchanger 300 and the outdoor heat exchanger 400, and a fifth expansion valve 850 and a filter 860 are installed on the downstream section 662 of the third main road.

[0084] The first end of the outdoor heat exchanger 400 is also equipped with a fourth expansion valve 840. The refrigerant output from the indoor heat exchanger 300 through the second main circuit 620, the refrigerant output from the first channel 510 through the downstream section of the first branch circuit 642, and the refrigerant output from the refrigeration channel 411 through the downstream section of the third main circuit 662 are all transported to the outdoor heat exchanger 400 through the fourth expansion valve 840.

[0085] When in heating mode and defrosting conditions are not met, the controller controls the first switching valve 710 and the second switching valve 720 to open, the third switching valve 730 to close, and the first branch 640 and the second branch 650 to be in the open state.

[0086] The high-temperature and high-pressure refrigerant output by the compressor 100 is transported to the indoor heat exchanger 300 for heat exchange after passing through the first valve port 210 and the second valve port 220. After heat exchange, the refrigerant passes through the third expansion valve 830, and then through the second main circuit 620 and the fourth expansion valve 840 to the outdoor heat exchanger 400. Another part of the refrigerant is input into the refrigeration passage 411 through the upstream section 661 of the third main circuit. After exchanging heat with the water flow in the cooling passage 412, it is also transported to the outdoor heat exchanger 400 through the downstream section 662 of the third main circuit.

[0087] After the two refrigerants enter the outdoor heat exchanger 400 for heat exchange, they are returned to the suction end of the compressor 100 after passing through the fourth valve port 240 and the third valve port 230 of the four-way valve 200.

[0088] When the defrosting conditions are met, the controller controls the first switching valve 710 and the second switching valve 720 to be closed, and the third switching valve 730 to be open.

[0089] The first branch 640 and the second branch 650 are connected.

[0090] When the air-side heat exchanger 310 and the water-side heat exchanger 410 are heating simultaneously, the high-temperature and high-pressure refrigerant output by the compressor 100 is divided into three paths and delivered to the air-side heat exchanger 310, the water-side heat exchanger 410 and the defrost heat exchanger 500 for heat exchange.

[0091] Specifically, the refrigerant delivered to the air-side heat exchanger 310 passes through the first valve port 210 and the second valve port 220 before being delivered to the indoor heat exchanger 300 for heat exchange. Subsequently, it passes through the second main line 620 and the fourth expansion valve 840 before being delivered to the outdoor heat exchanger 400.

[0092] The refrigerant delivered to the water-side heat exchanger 410 is fed into the refrigeration passage 411 through the upstream section 661 of the third main road. After exchanging heat with the water flow in the cooling passage 412, it is delivered to the outdoor heat exchanger 400 through the downstream section 662 of the third main road, the fifth expansion valve 850, and the fourth expansion valve 840.

[0093] The refrigerant delivered to the defrost heat exchanger 500 is specifically delivered to the first channel 510 via the upstream section 641 of the first branch, where it exchanges heat with the refrigerant in the second channel 520. After that, it is delivered to the outdoor heat exchanger 400 via the downstream section 642 of the first branch and the fourth expansion valve 840.

[0094] After heat exchange in the outdoor heat exchanger 400, the refrigerant is returned to the suction end of the compressor 100 via the fourth main circuit 630.

[0095] This defrosting method allows both the air-side heat exchanger 310 and the water-side heat exchanger 410 to maintain heating function, providing continuous heating for the user's indoor temperature while ensuring the user's hot water needs. It offers high heating continuity, good comfort, and eliminates the need to switch the four-way valve 200, which helps prevent liquid slugging in the compressor 100, reduces system impact, significantly improves energy efficiency, and extends equipment life.

[0096] In some embodiments of this application, there are multiple air-side heat exchangers 310, and each air-side heat exchanger 310 is connected in parallel between the first valve port 210 and the defrost heat exchanger 500 via a refrigerant auxiliary line. Each refrigerant auxiliary line is provided with a third expansion valve 830.

[0097] The air-side heat exchanger 310 can be installed in the same space or different spaces according to actual design requirements.

[0098] refer to Figures 8-10 Based on any of the above embodiments, the outdoor unit is also equipped with components and a temperature control element 900. The temperature control element 900 is connected to the outside of the components and is used to control the temperature of the components.

[0099] The temperature control element 900 is connected to the second main circuit 620 and is located between the third switch valve 730 and the outdoor heat exchanger 400. The downstream section 642 of the first branch is connected to the outdoor heat exchanger 400 through the temperature control element 900.

[0100] The refrigerant flowing through the temperature control element 900 has a low temperature, which can be used to absorb the heat generated during the operation of the components, thereby cooling the components and improving their service life.

[0101] A fourth expansion valve 840 is also provided between the temperature control element 900 and the outdoor heat exchanger 400, and filters 860 are provided on both sides of the fourth expansion valve 840.

[0102] Taking an embodiment of indoor heat exchanger 300 including an air-side heat exchanger and a water-side heat exchanger as an example, the specific working process of temperature control element 900 will be described in detail: When in heating mode and defrosting conditions are not met, the controller controls the first switching valve 710 and the second switching valve 720 to open, the third switching valve 730 to close, and the first branch 640 and the second branch 650 to be in the open state.

[0103] The high-temperature and high-pressure refrigerant output by the compressor 100 is transported to the indoor heat exchanger 300 for heat exchange after passing through the first valve port 210 and the second valve port 220. After heat exchange, the refrigerant passes through the third expansion valve 830, and then through the second main circuit 620 and the fourth expansion valve 840 to the outdoor heat exchanger 400. Another part of the refrigerant is input into the refrigeration passage 411 through the upstream section 661 of the third main circuit. After exchanging heat with the water flow in the cooling passage 412, it is also transported to the outdoor heat exchanger 400 through the downstream section 662 of the third main circuit.

[0104] Before the two refrigerants enter the outdoor heat exchanger 400 for heat exchange, they are first delivered to the temperature control element 900. The temperature control element 900 is also a refrigerant heat exchange element. The refrigerant delivered to the temperature control element 900 has a low temperature and can be used to absorb the heat generated during the operation of the components.

[0105] The refrigerant output from the temperature control unit 900 passes through the filter 860, the fourth expansion valve 840, and the filter 860 again before being delivered to the outdoor heat exchanger 400.

[0106] The refrigerant output from the outdoor heat exchanger 400 passes through the fourth valve port 240 and the third valve port 230 of the four-way valve 200 and is then returned to the suction end of the compressor 100.

[0107] The temperature control element 900 can make full use of the cooling capacity of the refrigerant to remove heat from the surface of the components and cool them down.

[0108] When the defrosting conditions are met, the controller controls the first switching valve 710 and the second switching valve 720 to be closed, and the third switching valve 730 to be open.

[0109] The first branch 640 and the second branch 650 are connected.

[0110] When the air-side heat exchanger 310 and the water-side heat exchanger 410 are heating simultaneously, the high-temperature and high-pressure refrigerant output by the compressor 100 is divided into three paths and delivered to the air-side heat exchanger 310, the water-side heat exchanger 410 and the defrost heat exchanger 500 for heat exchange.

[0111] Specifically, the refrigerant delivered to the air-side heat exchanger 310 passes through the first valve port 210 and the second valve port 220 before being delivered to the indoor heat exchanger 300 for heat exchange, and then through the second main line 620 to the outdoor heat exchanger 400.

[0112] The refrigerant delivered to the water-side heat exchanger 410 is fed into the refrigeration passage 411 through the upstream section 661 of the third main road. After exchanging heat with the water flow in the cooling passage 412, it is delivered to the outdoor heat exchanger 400 through the fifth expansion valve 850 from the downstream section 662 of the third main road.

[0113] The refrigerant delivered to the defrost heat exchanger 500 is specifically delivered to the first channel 510 via the upstream section 641 of the first branch, where it exchanges heat with the refrigerant in the second channel 520, and then delivered to the outdoor heat exchanger 400 via the downstream section 642 of the first branch.

[0114] Before entering the outdoor heat exchanger 400, the three refrigerants mentioned above are first delivered to the temperature control element 900. The refrigerant delivered to the temperature control element 900 has a lower temperature and can be used to absorb the heat generated during the operation of the components.

[0115] The refrigerant output from the temperature control unit 900 passes through the filter 860, the fourth expansion valve 840, and the filter 860 again before being delivered to the outdoor heat exchanger 400.

[0116] The refrigerant output from the outdoor heat exchanger 400 passes through the fourth valve port 240 and the third valve port 230 of the four-way valve 200 and is then returned to the suction end of the compressor 100.

[0117] The temperature control element 900 can make full use of the cooling capacity of the refrigerant to remove heat from the surface of the components and cool them down.

[0118] After heat exchange in the outdoor heat exchanger 400, the refrigerant is returned to the suction end of the compressor 100 via the fourth main circuit 630.

[0119] This defrosting method allows both the air-side indoor heat exchanger 300 and the water-side indoor heat exchanger 300 to maintain heating function, providing continuous heating for the user's indoor temperature while ensuring the user's hot water needs. It offers high heating continuity, good comfort, and eliminates the need to switch the four-way valve 200, which helps prevent liquid slugging in the compressor 100, reduces system impact, significantly improves energy efficiency, and extends equipment life.

[0120] In some embodiments of this application, a first pressure switch 110 is provided at the discharge end of the compressor 100, a second pressure switch 120 is provided at the suction end of the compressor 100, and a first pressure detection element 140 is provided between the water-side heat exchanger 410 and the discharge end of the compressor 100.

[0121] The working principle of an air conditioning pressure switch is based on changes in system pressure. When the system pressure is higher or lower than the set safety pressure, the sensor inside the pressure switch moves, pushing the switch connector to open or close via a connecting rod, thereby changing the on / off state of the control element and achieving the purpose of protecting the system.

[0122] Specifically, when the high pressure of the air conditioning system rises abnormally, the high pressure switch will detect this situation and cut off the control circuit of the compressor 100, causing the air conditioning system to stop working immediately to prevent dangerous situations such as explosions that may be caused by excessive system pressure.

[0123] When the air conditioning system leaks or the refrigerant is insufficient, the low-pressure switch will detect the pressure drop and cut off the control circuit of the compressor 100 to protect the compressor 100 from damage and prevent it from wearing or overheating due to lack of lubrication.

[0124] A gas-side shut-off valve 150 is provided between the second valve port 220 and the air-side heat exchanger 310, and a liquid-side shut-off valve 160 is provided between the air-side heat exchanger 310 and the third switching valve 730.

[0125] In a refrigeration or heating cycle, the gas-side shut-off valve 150 and the liquid-side shut-off valve 160 prevent refrigerant from flowing back into the system, ensuring that the refrigerant flows in the correct direction, thereby guaranteeing the normal operation and efficiency of the system.

[0126] Expansion valves are used to reduce the pressure of medium-temperature, high-pressure liquid refrigerant to low-pressure refrigerant that is easier to evaporate, and at the same time, they are used to precisely control the refrigerant flow rate to ensure system stability.

[0127] On the other hand, this application also proposes an air conditioner comprising: Indoor unit, which includes at least one indoor heat exchanger 300, The outdoor unit includes a compressor 100, a four-way valve 200, and an outdoor heat exchanger 400. Each port of the four-way valve 200 is connected to the discharge end of the compressor 100, the indoor heat exchanger 300, the suction end of the compressor 100, and the outdoor heat exchanger 400, respectively.

[0128] Among them, a first branch 640 is provided between the discharge end of the compressor 100 and the outdoor heat exchanger 400, and a second branch 650 is provided between the indoor heat exchanger 300 and the outdoor heat exchanger 400. The first branch 640 and the second branch 650 exchange heat through the defrost heat exchanger 500 to increase the refrigerant temperature in the second branch 650 and defrost the outdoor heat exchanger 400.

[0129] Specifically, the four-way valve 200 includes a first valve port 210, a second valve port 220, a third valve port 230, and a fourth valve port 240. The first valve port 210 is connected to the discharge end of the compressor 100, the second valve port 220 is connected to the first end of at least one indoor heat exchanger 300, the third valve port 230 is connected to the suction end of the compressor 100, and the fourth valve port 240 is connected to the second end of the outdoor heat exchanger 400. The first end of the outdoor heat exchanger 400 is connected to the second end of the indoor heat exchanger 300.

[0130] The outdoor unit is also equipped with a defrost heat exchanger 500, which includes a first channel 510 and a second channel 520; the first channel 510 and the second channel 520 can exchange heat with each other.

[0131] The first channel 510 is connected between the exhaust end of the compressor 100 and the first end of the outdoor heat exchanger 400.

[0132] Specifically, the two ends of the first channel 510 are connected to the exhaust end of the compressor 100 and the first end of the outdoor heat exchanger 400 through the first branch 640.

[0133] For ease of understanding and description, the first channel 510 and the exhaust end of the compressor 100 are connected by the upstream section 641 of the first branch, and the first channel 510 is connected to the first end of the outdoor heat exchanger 400 by the downstream section 642 of the first branch.

[0134] A first switching valve 710 is provided between the compressor 100 and the first channel 510 to control the connection and disconnection between the first channel 510 and the discharge end of the compressor 100.

[0135] Specifically, the first switching valve 710 is installed on the upstream section 641 of the first branch.

[0136] The second channel 520 is connected between the second end of the indoor heat exchanger 300 and the first end of the outdoor heat exchanger 400.

[0137] Specifically, the two ends of the second channel 520 are connected to the second end of the indoor heat exchanger 300 and the first end of the outdoor heat exchanger 400 through the second branch 650.

[0138] For ease of understanding and description, the first channel 510 and the second end of the indoor heat exchanger 300 are connected by the upstream section 651 of the second branch, and the second channel 520 is connected to the first end of the outdoor heat exchanger 400 by the downstream section 652 of the second branch.

[0139] A second switching valve 720 is provided between the second channel 520 and the indoor heat exchanger 300 to control the on / off connection between the indoor heat exchanger 300 and the second channel 520.

[0140] Specifically, the second switching valve 720 is installed on the upstream section 651 of the second branch.

[0141] The second valve port 220 and the indoor heat exchanger 300 are connected by the first main line 610. The second end of the indoor heat exchanger 300 is connected to the first end of the outdoor heat exchanger 400 through the second main line 620. The second end of the outdoor heat exchanger 400 is connected to the fourth valve port 240 of the four-way valve 200 through the fourth main line 630.

[0142] In some other embodiments, a first expansion valve 810 is provided on the downstream section 642 of the first branch, and a second expansion valve 820 is provided on the downstream section 652 of the second branch.

[0143] A third expansion valve 830 is provided between the indoor heat exchanger 300 and the outdoor heat exchanger 400.

[0144] In some embodiments, the indoor heat exchanger 300 includes at least one wind-side heat exchanger 310.

[0145] The air-side heat exchanger 310 is connected to the exhaust end of the compressor 100 via the first main line 610.

[0146] The first end of the air-side heat exchanger 310 is connected to the second valve port 220 of the four-way valve 200, and the second end of the air-side heat exchanger 310 is connected to the first end of the outdoor heat exchanger 400 through the second main line 620; a third switch valve 730 is provided on the second main line 620.

[0147] The water-side heat exchanger 410 is a water-side heat exchanger, which includes a refrigeration channel 411 and a cooling channel 412. The two ends of the refrigeration channel 411 are respectively connected to the exhaust end of the compressor 100 and the end of the second channel 520 away from the outdoor heat exchanger 400 through the third main channel.

[0148] The two ends of the cooling channel 412 are connected to the inlet water pipe and the outlet water pipe, respectively. The inlet water pipe delivers low-temperature water into the cooling channel 412, and the high-temperature water that has been heated by heat exchange with the cooling channel 411 is output to the water terminal through the outlet water pipe.

[0149] In some embodiments of this application, the cooling channel 412 is connected to the exhaust end of the compressor 100 via the upstream section 661 of the third main channel and to the second main channel 620 via the downstream section 662 of the third main channel. The connection point between the downstream section 662 of the third main channel and the second main channel 620 is located between the air-side heat exchanger 310 and the third switching valve 730. A fifth expansion valve 850 and a filter 860 are also provided on the downstream section 662 of the third main channel.

[0150] In other words, the refrigeration passage 411 is connected between the exhaust end of the compressor 100 and the second end of the indoor heat exchanger 300 via a third main passage.

[0151] For ease of understanding, the refrigeration aisle 411 is defined to be connected to the compressor 100 via the upstream section 661 of the third main road and to the indoor heat exchanger 300 via the downstream section 662 of the third main road.

[0152] The upstream section 641 of the first branch road and the upstream section 661 of the third main road are both connected to the fifth main road between the exhaust end of the compressor 100 and the first valve port 210.

[0153] The air-side heat exchanger 310 and the water-side heat exchanger 410 are used to regulate the indoor temperature. The water-side heat exchanger 410 can also be used to provide domestic hot water to users. During the defrosting process of the outdoor heat exchanger, when users only need the heating function, at least one of the air-side heat exchanger 310 and the water-side heat exchanger 410 will always remain in heating mode. When users need both heating and domestic hot water functions at the same time, the air-side heat exchanger 310 and the water-side heat exchanger 410 will always remain in heating mode to ensure user comfort and water demand.

[0154] In some embodiments of this application, a first switching valve 710 is disposed on the upstream section 641 of the first branch, and a first expansion valve 810 is disposed on the downstream end of the first branch 640.

[0155] The first switching valve 710 is used to control the opening and closing of the first channel 510. The opening of the first expansion valve 810 is adjustable and can be adjusted according to the defrosting status of the outdoor heat exchanger 400. This allows for precise defrosting control, improved defrosting efficiency, reduced energy consumption, and control of suction superheat to prevent liquid slugging in the compressor 100.

[0156] Similar to the previous embodiment, the second valve port 220 and the indoor heat exchanger 300 are connected by the first main line 610, the second end of the indoor heat exchanger 300 is connected to the first end of the outdoor heat exchanger 400 through the second main line 620, and the second end of the outdoor heat exchanger 400 is connected to the fourth valve port 240 of the four-way valve 200 through the fourth main line 630.

[0157] In some other embodiments, a first expansion valve 810 is provided on the downstream section 642 of the first branch, and a second expansion valve 820 is provided on the downstream section 652 of the second branch.

[0158] A third expansion valve 830 and a fourth expansion valve 840 are installed between the indoor heat exchanger 300 and the outdoor heat exchanger 400, and a fifth expansion valve 850 and a filter 860 are installed on the downstream section 662 of the third main road.

[0159] When the defrosting conditions are met, the controller controls the first switching valve 710 and the second switching valve 720 to be closed, and the third switching valve 730 to be open.

[0160] The first branch 640 and the second branch 650 are connected.

[0161] When the air-side heat exchanger 310 and the water-side heat exchanger 410 are heating simultaneously, the high-temperature and high-pressure refrigerant output by the compressor 100 is divided into three paths and delivered to the air-side heat exchanger 310, the water-side heat exchanger 410 and the defrost heat exchanger 500 for heat exchange.

[0162] When only the water-side heat exchanger 410 is used for heating, the high-temperature and high-pressure refrigerant output by the compressor 100 is divided into two paths and delivered to the water-side heat exchanger 410 and the defrost heat exchanger 500 respectively for heat exchange.

[0163] Specifically, the refrigerant delivered to the air-side heat exchanger 310 passes through the first valve port 210 and the second valve port 220 before being delivered to the indoor heat exchanger 300 for heat exchange, and then through the second main line 620 to the outdoor heat exchanger 400.

[0164] The refrigerant delivered to the water-side heat exchanger 410 is fed into the refrigeration passage 411 through the upstream section 661 of the third main road. After exchanging heat with the water flow in the cooling passage 412, it is delivered to the outdoor heat exchanger 400 through the fifth expansion valve 850 from the downstream section 662 of the third main road.

[0165] The refrigerant delivered to the defrost heat exchanger 500 is specifically delivered to the first channel 510 via the upstream section 641 of the first branch, where it exchanges heat with the refrigerant in the second channel 520, and then delivered to the outdoor heat exchanger 400 via the downstream section 642 of the first branch.

[0166] After heat exchange in the outdoor heat exchanger 400, the refrigerant is returned to the suction end of the compressor 100 via the fourth main circuit 630.

[0167] When the system determines that the defrosting end conditions are met, the first switching valve 710 and the second switching valve 720 close, the third switching valve 730 opens, and the first expansion valve 810 and the second expansion valve 820 close. Otherwise, the defrosting state continues. After defrosting is completed, the unit enters normal heating operation control. In this state, since the first branch 640 and the second branch 650 are closed, the low-temperature, low-pressure liquid refrigerant from the air-side heat exchanger 310 and the water-side heat exchanger 410 enters the outdoor heat exchanger 400 through the fourth expansion valve 840.

[0168] In order to accurately control the defrosting process, avoid over-defrosting or under-defrosting, improve defrosting efficiency, and reduce energy consumption, this application uses a controller to control the opening degree of the first expansion valve 810 and the second expansion valve 820 in real time.

[0169] The outdoor heat exchanger 400 is equipped with a temperature detection device to detect the temperature of the liquid pipe in the outdoor heat exchanger 400, and a pressure detection device 140 is installed on the exhaust side of the compressor 100 to detect the exhaust pressure of the compressor 100.

[0170] When the preset defrosting ends, the liquid pipe temperature of the outdoor heat exchanger 400 is Temax; when defrosting begins, the liquid pipe temperature of the outdoor heat exchanger 400 is Temin; and the real-time liquid pipe temperature of the outdoor heat exchanger 400 is Te.

[0171] When the temperature of the liquid pipe detected by the temperature sensor is Temin, the controller starts defrosting. That is, the first switch valve 710 and the second switch valve 720 are closed, the third switch valve 730 is opened, and the controller controls the opening degree of the first expansion valve 810 to C1 and the opening degree of the second expansion valve 820 to C2.

[0172] The controller controls the opening C1 of the first expansion valve 810 and the opening C2 of the second expansion valve 820 based on the temperature difference ΔTe between the liquid pipe temperature Temax at the end of defrosting and the real-time liquid pipe temperature Te.

[0173] As defrosting proceeds, the real-time liquid pipe temperature Te of the outdoor heat exchanger 400 increases, and the temperature difference ΔTe gradually decreases from the initial ΔTe = Temax - Temin. Correspondingly, the opening degree C1 of the first expansion valve 810 and the opening degree C2 of the second expansion valve 820 also decrease.

[0174] For example, but not limited to: refer to Figure 11 The opening degrees of the first expansion valve 810 and the second expansion valve 820 are controlled in a trapezoidal manner according to the temperature difference ΔTe.

[0175] For ease of understanding, Temax-Temin=△T1 is defined, with a℃ as a gradient, and the first expansion valve 810 and the second expansion valve 820 are gradually reduced based on the initial opening degrees C1 and C2.

[0176] Controlling the opening of the first expansion valve 810 and the second expansion valve 820 helps improve defrosting accuracy, avoids over-defrosting or under-defrosting, improves defrosting efficiency, and reduces energy consumption. In addition, it can maintain stable system pressure, reduce thermal stress shock, extend component life, and control suction superheat to prevent compressor liquid slugging.

[0177] Whenever possible, the various aspects and features described and shown in the specification can be applied individually, and these individual aspects can serve as the subject of a divisional application.

[0178] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0179] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. An air conditioner, characterized in that, include: Indoor unit, which includes indoor heat exchanger, The outdoor unit includes a compressor, a four-way valve, and an outdoor heat exchanger. The four-way valve includes a first valve port, a second valve port, a third valve port, and a fourth valve port. The first valve port is connected to the discharge end of the compressor, the second valve port is connected to the first end of at least one of the indoor heat exchangers, the third valve port is connected to the suction end of the compressor, and the fourth valve port is connected to the second end of the outdoor heat exchanger. The first end of the outdoor heat exchanger is connected to the second end of the indoor heat exchanger. The outdoor unit is also equipped with a defrost heat exchanger, which includes a first channel and a second channel. The two ends of the first channel are connected to the exhaust end of the compressor and the first end of the outdoor heat exchanger via a first branch, and a first switching valve is provided between the compressor and the first channel; the two ends of the second channel are connected to the second end of the indoor heat exchanger and the first end of the outdoor heat exchanger via a second branch, and a second switching valve is provided between the second channel and the indoor heat exchanger.

2. The air conditioner according to claim 1, characterized in that, The indoor heat exchanger includes at least one air-side heat exchanger; The air-side heat exchanger is connected to the exhaust end of the compressor via a first main line; the first end of the air-side heat exchanger is connected to the second valve port of the four-way valve; the second end of the air-side heat exchanger is connected to the first end of the outdoor heat exchanger via a second main line; a third switching valve is provided on the second main line. The outdoor unit also includes a water-side heat exchanger, which includes a refrigeration channel and a cooling channel. The two ends of the refrigeration channel are respectively connected to the exhaust end of the compressor and the end of the second channel away from the outdoor heat exchanger via a third main channel.

3. The air conditioner according to claim 2, characterized in that, The first channel and the exhaust end of the compressor are connected by the upstream section of the first branch, and the first channel and the outdoor heat exchanger are connected by the downstream section of the first branch; The first switching valve is installed on the upstream section of the first branch, and the first expansion valve is installed on the downstream end of the first branch.

4. The air conditioner according to claim 2, characterized in that, The second channel is connected to the second main road via the upstream section of the second branch road, and the connection point between the upstream section of the second branch road and the second main road is located between the air-side heat exchanger and the third switching valve; the second channel is connected to the outdoor heat exchanger via the downstream section of the second branch road. The second switching valve is installed on the upstream section of the second branch, and the second expansion valve is installed on the downstream section of the second branch.

5. The air conditioner according to claim 2, characterized in that, There are multiple air-side heat exchangers, and each air-side heat exchanger is connected in parallel between the first valve port and the defrost heat exchanger via a refrigerant auxiliary line. Each refrigerant auxiliary line is equipped with a third expansion valve.

6. The air conditioner according to claim 3, characterized in that, The outdoor unit is also equipped with components and a temperature control device. The temperature control device is connected to the outside of the components and is used to control the temperature of the components. The temperature control device is connected to the second main line and is located between the third switch valve and the outdoor heat exchanger. The downstream section of the first branch is connected to the outdoor heat exchanger through the temperature control device.

7. The air conditioner according to claim 6, characterized in that, A fourth expansion valve is also provided between the temperature control element and the outdoor heat exchanger, and filters are provided on both sides of the fourth expansion valve.

8. The air conditioner according to claim 2, characterized in that, The compressor has a first pressure switch at the exhaust end and a second pressure switch at the intake end. A first pressure detection element is provided between the water-side heat exchanger and the compressor's exhaust end.

9. The air conditioner according to claim 2, characterized in that, The cooling channel is connected to the exhaust end of the compressor via the upstream section of the third main road and to the second main road via the downstream section of the third main road. The connection point between the downstream section of the third main road and the second main road is located between the air-side heat exchanger and the third switching valve. A fifth expansion valve and a filter are also provided on the downstream section of the third main road. A gas-side shut-off valve is provided between the second valve port and the air-side heat exchanger, and a liquid-side shut-off valve is provided between the air-side heat exchanger and the third switching valve.

10. An air conditioner, characterized in that, include: Indoor unit, which includes at least one indoor heat exchanger, The outdoor unit includes a compressor, a four-way valve, and an outdoor heat exchanger. Each port of the four-way valve is connected to the discharge end of the compressor, the indoor heat exchanger, the suction end of the compressor, and the outdoor heat exchanger, respectively. The compressor's exhaust end is connected to the outdoor heat exchanger via a first branch, and the indoor heat exchanger is connected to the outdoor heat exchanger via a second branch. The first and second branches exchange heat through a defrost heat exchanger to increase the refrigerant temperature in the second branch and defrost the outdoor heat exchanger.

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