Multi-connected air conditioning unit

Abstract

This application relates to a multi-split air conditioning unit, which includes: a compressor, a subcooler, a first phase change module, a second phase change module, an indoor heat exchange branch, a first make-up gas circuit, a control unit, and multiple switching units. The indoor heat exchange branch is located between the compressor's exhaust port and a first port of the subcooler, and the first make-up gas circuit is located between a second port of the subcooler and a make-up gas port of the compressor. The first phase change module is coupled to the indoor heat exchange branch and the first make-up gas circuit, and the second phase change module is embedded in the first make-up gas circuit. Multiple switching units are located in the indoor heat exchange branch and the first make-up gas circuit, and are electrically connected to the control unit. This design can cover complex operating conditions over a wide temperature range, thus improving the overall performance of the multi-split air conditioning unit.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and in particular to a multi-split air conditioning unit. Background Technology

[0002] Multi-split air conditioning units are widely used in both commercial and residential sectors due to their advantages such as flexible installation and energy efficiency. However, existing multi-split air conditioning units typically use single-stage phase change materials for heat or cold storage, which makes them unable to cover complex operating conditions across a wide temperature range and prone to issues with relatively low overall performance. Therefore, improving the overall performance of multi-split air conditioning units has become an urgent technical problem to be solved. Utility Model Content

[0003] This application provides a multi-split air conditioning unit to solve the problem that existing multi-split air conditioning units typically use single-stage phase change materials for heat or cold storage, which can easily result in low overall performance.

[0004] In a first aspect, embodiments of this application provide a multi-split air conditioning unit, which includes: a compressor, a subcooler, a first phase change module, a second phase change module, an indoor heat exchange branch, a first gas supply circuit, a control unit, and multiple switching units;

[0005] The indoor heat exchange branch is located between the exhaust port of the compressor and the first port of the subcooler, and the first gas supply circuit is located between the second port of the subcooler and the gas supply port of the compressor.

[0006] The first phase change module is coupled to the indoor heat exchange branch and the first gas supply circuit, and the second phase change module is embedded in the first gas supply circuit;

[0007] The plurality of switching units are disposed on the indoor heat exchange branch and the first gas supply circuit, and the plurality of switching units are electrically connected to the control unit.

[0008] Optionally, the indoor heat exchange branch includes a first pipeline, the first air supply circuit includes a second pipeline, and the plurality of switching units include a first switching unit, a second switching unit, and a third switching unit;

[0009] Wherein, the first end of the first pipeline is connected to the first connection point on the indoor heat exchange branch, and the second end of the first pipeline is connected to the second connection point on the indoor heat exchange branch. Both the first connection point and the second connection point are located downstream of the compressor's exhaust port.

[0010] The first end of the second pipeline is connected to the second port of the subcooler, and the second end of the second pipeline is connected to the gas supply port of the compressor.

[0011] The first phase change module is coupled to the first pipeline and the second pipeline, the first switch unit is disposed on the first pipeline, and the second switch unit and the third switch unit are disposed on the second pipeline, with the second switch unit and the third switch unit located upstream and downstream of the first phase change module, respectively.

[0012] Optionally, the first gas replenishment circuit further includes a third pipeline, and the plurality of switching units further includes a fourth switching unit;

[0013] Wherein, the first end of the third pipeline is connected to the third connection point on the second pipeline, and the second end of the third pipeline is connected to the fourth connection point on the second pipeline. The third connection point and the fourth connection point are located upstream and downstream of the third switch unit, respectively.

[0014] Both the second phase change module and the fourth switching unit are disposed on the third pipeline.

[0015] Optionally, the first gas replenishment circuit further includes a fourth pipeline, and the plurality of switching units further includes a fifth switching unit;

[0016] Wherein, the first end of the fourth pipeline is connected to the second port of the subcooler, and the second end of the fourth pipeline is connected to the fifth connection point on the third pipeline. The fifth connection point is located between the second phase change module and the fourth switching unit.

[0017] The fifth switch unit is disposed on the third pipeline.

[0018] Optionally, the multi-split air conditioning unit further includes a third phase change module and an outdoor heat exchange branch; wherein, the outdoor heat exchange branch is disposed between the third port of the subcooler and the suction port of the compressor, and the third phase change module is embedded in the outdoor heat exchange branch.

[0019] Optionally, the multi-split air conditioning unit further includes an outdoor heat exchanger and a gas-liquid separator, and the outdoor heat exchange branch includes a fifth pipe, a sixth pipe, and a seventh pipe;

[0020] Wherein, the first end of the fifth pipe is connected to the third port of the subcooler, and the second end of the fifth pipe is connected to the first port of the outdoor heat exchanger;

[0021] The first end of the sixth pipeline is connected to the second port of the outdoor heat exchanger, and the second end of the sixth pipeline is connected to the air intake of the gas-liquid separator.

[0022] The first end of the seventh pipeline is connected to the exhaust port of the gas-liquid separator, and the second end of the seventh pipeline is connected to the suction port of the compressor.

[0023] The third phase change module is embedded in the fifth pipeline.

[0024] Optionally, the multi-split air conditioning unit further includes a second gas supply circuit, and the plurality of switching units further includes a sixth switching unit;

[0025] The second gas replenishment circuit is located between the second port of the subcooler and the gas replenishment port of the gas-liquid separator.

[0026] The sixth switch unit is located on the second gas supply circuit.

[0027] Optionally, the phase change material selected for the first phase change module is erythritol, the phase change material selected for the second phase change module is modified paraffin, and the phase change material selected for the third phase change module is calcium chloride hexahydrate solution.

[0028] Optionally, the phase change temperature of the first phase change module is 50°C to 70°C, the phase change temperature of the second phase change module is 20°C to 50°C, and the phase change temperature of the third phase change module is -20°C to 20°C.

[0029] Compared with the prior art, the technical solution provided in this application has the following advantages: The multi-split air conditioning unit provided in this application includes: a compressor, a subcooler, a first phase change module, a second phase change module, an indoor heat exchange branch, a first gas replenishment circuit, a control unit, and multiple switching units; wherein, the indoor heat exchange branch is disposed between the exhaust port of the compressor and the first port of the subcooler, and the first gas replenishment circuit is disposed between the second port of the subcooler and the gas replenishment port of the compressor; the first phase change module is coupled to the indoor heat exchange branch and the first gas replenishment circuit, and the second phase change module is embedded in the first gas replenishment circuit; the multiple switching units are disposed on the indoor heat exchange branch and the first gas replenishment circuit, and the multiple switching units are electrically connected to the control unit. In this way, the first and second phase change modules with different phase change temperatures can be used to absorb or release heat from the refrigerant in the indoor heat exchange branch and the first gas replenishment circuit, thereby covering complex operating conditions over a wide temperature range and improving the overall performance of the multi-split air conditioning unit. Attached Figure Description

[0030] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0033] Figure 1 This is a schematic diagram of the structure of a multi-split air conditioning unit provided in an embodiment of this application;

[0034] Figure 2 This is a schematic diagram of the structure of another multi-split air conditioning unit provided in the embodiments of this application;

[0035] Figure 3 This is a flowchart illustrating a control method for a multi-split air conditioning unit provided in an embodiment of this application. Attached image description:

[0037] 100. Compressor; 110. Subcooler; 120. First phase change module; 130. Second phase change module; 140. Third phase change module; 150. Indoor heat exchange branch; 160. Outdoor heat exchange branch; 170. First gas supply circuit; 1501. First pipeline; 1701. Second pipeline; 1801. First switching unit; 1802. Second switching unit; 1803. Third switching unit; 1702. Third pipeline; 1804. Fourth... Switching unit; 1703, fourth pipeline; 1805, fifth switching unit; 190, outdoor heat exchanger; 200, gas-liquid separator; 1601, fifth pipeline; 1602, sixth pipeline; 1603, seventh pipeline; 220, four-way reversing valve; 230, oil separator; 240, indoor heat exchanger; 250, first electronic expansion valve; 260, second electronic expansion valve; 210, second gas replenishment circuit; 1806, sixth switching unit. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, 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, 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.

[0039] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. 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 this application. 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.

[0040] To address the issue that existing multi-split air conditioning units typically use single-stage phase change materials for heat or cold storage, which often results in relatively low overall performance, this application provides a multi-split air conditioning unit that can improve the overall performance of multi-split air conditioning units.

[0041] See Figure 1 and Figure 2 , Figure 1 and Figure 2 This is a schematic diagram of the structure of a multi-split air conditioning unit provided in an embodiment of this application. Figure 1 and Figure 2 As shown, the multi-split air conditioning unit may include: compressor 100, subcooler 110, first phase change module 120, second phase change module 130, indoor heat exchange branch 150, first gas supply circuit 170, control unit (not shown in the figure) and multiple switching units (not shown in the figure);

[0042] The indoor heat exchange branch 150 is located between the exhaust port of the compressor 100 and the first port of the subcooler 110, and the first gas supply circuit 170 is located between the second port of the subcooler 110 and the gas supply port of the compressor 100.

[0043] The first phase change module 120 is coupled to the indoor heat exchange branch 150 and the first gas supply circuit 170, and the second phase change module 130 is embedded in the first gas supply circuit 170.

[0044] Multiple switching units are installed on the indoor heat exchange branch 150, the outdoor heat exchange branch 160, and the first air supply circuit 170, and the multiple switching units are electrically connected to the control unit.

[0045] Specifically, the first phase change module 120 and the second phase change module 130 can be phase change modules formed by using different phase change materials or the same phase change material. Their main function is to achieve thermal energy management through the energy storage characteristics of the phase change material (i.e., the characteristic of the phase change material to absorb / release latent heat during solid-liquid transition). As an optional implementation, the first phase change module 120 can be a high-temperature phase change module, and the second phase change module 130 can be a medium-temperature phase change module.

[0046] The aforementioned indoor heat exchange branch 150 refers to the branch used to achieve indoor heat exchange. This indoor heat exchange branch 150 may be equipped with structures such as an oil separator 230, a four-way reversing valve 220, an indoor heat exchanger 240, and a first electronic expansion valve 250. The aforementioned first gas replenishment circuit 170 refers to the branch used to achieve gas replenishment and enthalpy increase. This first gas replenishment circuit 170 may include multiple pipelines, each pipeline being equipped with at least one switching unit.

[0047] The aforementioned control unit can be an existing control unit of the multi-split air conditioning unit, or it can be a newly added control unit in this application. The number and location of the aforementioned multiple switching units can be set according to actual needs, and this application embodiment does not impose specific limitations. The switching unit here can be a solenoid valve or similar structure.

[0048] The first phase change module 120 is coupled to the indoor heat exchange branch 150 and the first gas replenishment circuit 170. Therefore, the first phase change module 120 can absorb heat from the refrigerant in the indoor heat exchange branch 150 and release heat from the refrigerant in the first gas replenishment circuit 170, thereby achieving heat exchange between the indoor heat exchange branch 150 and the first gas replenishment circuit 170. The second phase change module 130 is embedded in the first gas replenishment circuit 170, thus allowing the second phase change module 130 to absorb heat from the refrigerant after heat exchange in the first gas replenishment circuit 170.

[0049] In this way, the first phase change module 120 and the second phase change module 130, which have different phase change temperatures, can be used to absorb or release heat from the refrigerant in the indoor heat exchange branch 150 and the first gas replenishment circuit 170, thereby covering complex operating conditions over a wide temperature range and improving the overall performance of the multi-split air conditioning unit.

[0050] In an alternative embodiment, see Figure 2 The indoor heat exchange branch 150 includes a first pipeline 1501, the first air supply circuit 170 includes a second pipeline 1701, and the multiple switching units include a first switching unit 1801, a second switching unit 1802 and a third switching unit 1803.

[0051] The first end of the first pipe 1501 is connected to the first connection point on the indoor heat exchange branch 150, and the second end of the first pipe 1501 is connected to the second connection point on the indoor heat exchange branch 150. Both the first connection point and the second connection point are located downstream of the exhaust port of the compressor 100.

[0052] The first end of the second pipe 1701 is connected to the second port of the subcooler 110, and the second end of the second pipe 1701 is connected to the gas supply port of the compressor 100.

[0053] The first phase change module 120 is coupled to the first pipeline 1501 and the second pipeline 1701. The first switch unit 1801 is disposed on the first pipeline 1501. The second switch unit 1802 and the third switch unit 1803 are disposed on the second pipeline 1701, and the second switch unit 1802 and the third switch unit 1803 are respectively located upstream and downstream of the first phase change module 120.

[0054] Specifically, a portion of the high-temperature, high-pressure refrigerant discharged from the compressor 100's discharge port returns to the compressor 100's discharge pipe via the first pipeline 1501, while the other portion enters the indoor heat exchanger 240 via the oil separator 230 and the four-way reversing valve 220 for condensation and heat release to supply heat to the room. Then, a portion of the refrigerant output from the indoor heat exchanger 240 can enter the outdoor heat exchanger 190 via the third phase change module 140, absorb heat from the outdoor air, evaporate into gas, and then return to the compressor 100's suction port via the four-way reversing valve 220 and the gas-liquid separator 200. The other portion of the refrigerant output from the indoor heat exchanger can enter the second pipeline 1701 via the subcooler 110, and then enter the compressor 100's gas supply port via the second pipeline.

[0055] In this way, when the high-temperature, high-pressure refrigerant flows through the first pipe 1501, it absorbs and stores the heat from the high-temperature, high-pressure refrigerant through the first phase change module 120. When the low-temperature, low-pressure refrigerant after heat exchange flows through the second pipe 1701, it releases the previously stored heat through the first phase change module 120, thereby increasing the temperature of the enthalpy-increasing refrigerant. This reduces the risk of liquid slugging caused by refrigerant carrying liquid in the first gas injection circuit 170 under low-temperature conditions, and also reduces the power consumption fluctuation of the compressor 100 while ensuring the reliability of the multi-split air conditioning unit.

[0056] In an alternative embodiment, see continue to see Figure 2 The first gas replenishment circuit 170 also includes a third pipeline 1702, and the multiple switching units also include a fourth switching unit 1804;

[0057] The first end of the third pipe 1702 is connected to the third connection point on the second pipe 1701, and the second end of the third pipe 1702 is connected to the fourth connection point on the second pipe 1701. The third connection point and the fourth connection point are located upstream and downstream of the third switch unit 1803, respectively.

[0058] The second phase change module 130 and the fourth switch unit 1804 are both located on the third pipeline 1702.

[0059] Specifically, the second phase change module 130 can be directly coupled to the third pipeline 1702 via a shell-and-tube heat exchanger.

[0060] A third pipeline 1702 is connected in parallel at the third switch unit 1803. This allows the refrigerant, after being heated by the first phase change module 120, to bypass the second pipeline 1701 from flowing directly into the compressor 100's gas supply port when the refrigerant temperature is too high. Instead, the refrigerant flows through the third pipeline 1702, absorbs heat through the second phase change module 130, and then flows into the compressor 100's gas supply port. Conversely, if the refrigerant temperature after being heated by the first phase change module 120 is too low, the refrigerant flows through the third pipeline 1702, releases heat through the second phase change module 130, and then flows into the compressor 100's gas supply port when the refrigerant temperature is too low.

[0061] In this way, heat can be dynamically absorbed or released through the second phase change module 130 to balance the superheat and subcooling of the refrigerant in the first gas replenishment circuit 170, suppress the frequency fluctuation of the compressor 100 caused by sudden load changes, and improve the unit's operational stability and energy efficiency consistency.

[0062] In an alternative embodiment, see continue to see Figure 2 The first gas replenishment circuit 170 also includes a fourth pipeline 1703, and the multiple switching units also include a fifth switching unit 1805;

[0063] Among them, the first end of the fourth pipe 1703 is connected to the second port of the subcooler 110, and the second end of the fourth pipe 1703 is connected to the fifth connection point on the third pipe 1702. The fifth connection point is located between the second phase change module 130 and the fourth switch unit 1804.

[0064] The fifth switch unit 1805 is installed on the third pipeline 1702.

[0065] Specifically, since one end of the fifth switching unit 1805 is connected to the second port of the subcooler 110 and the other end of the fifth switching unit 1805 is connected to the second phase change module 130, when the ambient temperature is high, the refrigerant entering the first gas supply circuit 170 from the subcooler 110 can be heated without passing through the second pipeline 1701. Instead, it can flow through the fifth switching unit 1805 on the fourth pipeline 1703, and then through the second phase change module 130 to absorb or release heat before flowing into the gas supply port of the compressor 100, thereby reducing the fluctuation of the gas supply temperature.

[0066] In an optional embodiment, the multi-split air conditioning unit further includes a third phase change module 140 and an outdoor heat exchange branch 160; wherein, the outdoor heat exchange branch 160 is disposed between the third port of the subcooler 110 and the suction port of the compressor 100, and the third phase change module 140 is embedded in the outdoor heat exchange branch 160.

[0067] Specifically, the third phase change module 140 may use different phase change materials or the same phase change materials as the first phase change module 120 and the second phase change module 130. As an optional implementation, the third phase change module 140 may be a low-temperature phase change module.

[0068] The aforementioned outdoor heat exchange branch 160 refers to a branch used to achieve outdoor heat exchange. The outdoor heat exchange branch 160 may be equipped with structures such as a second electronic expansion valve 260, an outdoor heat exchanger 190, a four-way reversing valve 220, and a gas-liquid separator 200.

[0069] The third phase change module 140 is embedded in the outdoor heat exchange branch 160, so the third phase change module 140 can be used to absorb or release heat from the refrigerant in the outdoor heat exchange branch 160.

[0070] In this way, the third phase change module 140 can be used to absorb or release heat from the refrigerant in the outdoor heat exchange branch 160, thereby covering complex operating conditions over a wide temperature range and improving the overall performance of the multi-split air conditioning unit.

[0071] In an alternative embodiment, see continue to see Figure 2 The multi-split air conditioning unit also includes an outdoor heat exchanger 190 and a gas-liquid separator 200, and the outdoor heat exchange branch 160 includes a fifth pipe 1601, a sixth pipe 1602 and a seventh pipe 1603.

[0072] The first end of the fifth pipe 1601 is connected to the third port of the subcooler 110, and the second end of the fifth pipe 1601 is connected to the first port of the outdoor heat exchanger 190.

[0073] The first end of the sixth pipe 1602 is connected to the second port of the outdoor heat exchanger 190, and the second end of the sixth pipe 1602 is connected to the air intake of the gas-liquid separator 200.

[0074] The first end of the seventh pipe 1603 is connected to the exhaust port of the gas-liquid separator 200, and the second end of the seventh pipe 1603 is connected to the suction port of the compressor 100.

[0075] The third phase change module 140 is embedded in the fifth pipeline 1601.

[0076] Specifically, the third phase change module 140 is embedded in the fifth pipeline 1601, meaning it is installed near the inlet of the outdoor heat exchanger 190. In winter heating, the third phase change module 140 can absorb waste heat from the pipeline during heating. During defrosting, the four-way reversing valve 220 reverses the flow, allowing the high-temperature, high-pressure refrigerant from the compressor 100 to enter the outdoor heat exchanger 190 via the four-way reversing valve 220, where it condenses and releases heat for defrosting. The refrigerant then passes through the second electronic expansion valve 260, becoming a low-temperature, low-pressure liquid, before entering the third phase change module 140 to absorb heat from the phase change material and evaporate into a gas. Finally, it passes through the first electronic expansion valve 250, the indoor heat exchanger 240, and the gas-liquid separator 200 back to the compressor 100's suction port. During defrosting, the third phase change module 140 acts as a low-grade heat source, providing sufficient heat for the defrosting process and increasing the defrosting speed. During summer cooling, it absorbs the heat from the refrigerant flowing out of the outdoor heat exchanger 190 and pre-cools it before the subcooler 110, achieving bipolar subcooling and greatly improving the degree of subcooling during cooling.

[0077] In an optional embodiment, the multi-split air conditioning unit further includes a second gas supply circuit 210, and the plurality of switching units further include a sixth switching unit 1806;

[0078] The second gas supply circuit 210 is located between the second port of the subcooler 110 and the gas supply port of the gas-liquid separator 200.

[0079] The sixth switch unit 1806 is located on the second gas supply circuit 210.

[0080] Specifically, part of the refrigerant flowing out of the subcooler 110 can return to the gas inlet of the compressor 100 via the first gas supply circuit 170, and the other part can return to the gas-liquid separator 200 via the second gas supply circuit 210, and then flow from the gas-liquid separator 200 into the gas inlet of the compressor 100.

[0081] In this way, the second gas replenishment circuit 210 can be used to achieve gas-liquid two-phase separation, ensuring that only saturated gas (or superheated gaseous refrigerant) enters the gas replenishment port of the compressor 100, thereby preventing the risk of liquid slugging and optimizing the gas replenishment efficiency.

[0082] In one optional embodiment, the phase change material selected for the first phase change module 120 is erythritol, the phase change material selected for the second phase change module 130 is modified paraffin, and the phase change material selected for the third phase change module 140 is calcium chloride hexahydrate solution.

[0083] Specifically, the first phase change module 120 can be made of erythritol as the phase change material. 10Erythritol (O4) is a tetracarbon sugar alcohol belonging to the polyol family. It is naturally found in certain fruits (such as grapes and pears) and fermented foods (such as soy sauce and wine). Industrially, it is usually produced from glucose through microbial fermentation (such as using yeast or mold). Erythritol has a phase transition enthalpy (latent heat) as high as about 340 kJ / kg, which is much higher than that of paraffin and inorganic hydrated salts. This means that it can store or release more heat energy, thus increasing its energy storage density.

[0084] The second phase change module 130 mentioned above can use modified paraffin as the phase change material. This modified paraffin is a phase change material that optimizes traditional paraffin through physical or chemical methods, aiming to improve its thermal conductivity, stability, phase change temperature, and other properties to meet the needs of different application scenarios. The latent heat of modified paraffin can reach 150–250 kJ / kg, which is slightly lower than erythritol but much higher than inorganic hydrated salts (such as sodium sulfate) and some fatty acid-based phase change materials, exhibiting strong heat storage capacity per unit volume.

[0085] The aforementioned third phase change module 140 can use calcium chloride hexahydrate solution as the phase change material. This calcium chloride hexahydrate (CaCl2·6H2O) solution is a crystalline hydrate formed from calcium chloride (CaCl2) and water (H2O). It is an important inorganic phase change material widely used in energy storage, temperature control, and other fields. The latent heat of calcium chloride hexahydrate can reach 190 kJ / kg, comparable to that of paraffin wax, but at a lower cost.

[0086] In this embodiment, by selecting different phase change materials as high, medium and low temperature three-stage phase change modules, we can synergistically cover extreme cooling and heating scenarios, accurately adjust the gas replenishment state, break the limitations of single-stage phase change materials, and thus better achieve the energy efficiency stability and comprehensive performance leap of multi-split air conditioning units.

[0087] In an optional embodiment, the phase change temperature of the first phase change module 120 is 50°C to 70°C, the phase change temperature of the second phase change module 130 is 20°C to 50°C, and the phase change temperature of the third phase change module 140 is -20°C to 20°C.

[0088] Specifically, the phase change temperature of the first phase change module 120 can be from 50°C to 70°C, the phase change temperature of the second phase change module 130 can be from 20°C to 50°C, and the phase change temperature of the third phase change module 140 can be from -20°C to 20°C. In this way, the high, medium, and low temperature three-stage phase change modules can cover complex operating conditions across a wide temperature range of -20°C to 70°C, breaking the limitations of single-stage phase change materials and thus better achieving a leap in energy efficiency stability and overall performance of multi-split air conditioning units.

[0089] See Figure 3 , Figure 3 This is a flowchart illustrating a control method for a multi-split air conditioning unit provided in an embodiment of this application. Figure 3 As shown, the control method for this multi-split air conditioning unit can be applied to the multi-split air conditioning unit in any of the foregoing embodiments. The control method for this multi-split air conditioning unit may include the following steps:

[0090] Step S301: Obtain the outdoor ambient temperature and the gas supply temperature.

[0091] Specifically, the aforementioned outdoor ambient temperature refers to the temperature of the outdoor air, which can be obtained through a temperature sensor installed on the outdoor unit. The aforementioned refrigerant charge temperature refers to the temperature of the refrigerant flowing into the compressor's charge port, which can be obtained through a temperature sensor installed on the compressor's charge port.

[0092] Step S302: Control the operating status of the first phase change module and the second phase change module according to the outdoor ambient temperature and the gas supply temperature.

[0093] After obtaining the outdoor ambient temperature and the gas supply temperature, the operating status of the first phase change module and the second phase change module can be controlled based on these temperatures.

[0094] In this way, the operating status of the first and second phase change modules can be controlled according to the outdoor ambient temperature and the gas injection temperature, thereby enabling the refrigerant in the indoor heat exchange branch and the first gas injection circuit to absorb and exchange heat, thus breaking through the application limitations of single-stage phase change materials and significantly improving the overall performance of the unit.

[0095] In an optional embodiment, step S302, controlling the operating states of the first phase change module and the second phase change module based on the outdoor ambient temperature and the gas supply temperature, includes:

[0096] When the outdoor ambient temperature is lower than the first preset temperature and the gas supply temperature is lower than the second preset temperature, the first phase change module is activated to exchange heat between the refrigerant in the indoor heat exchange branch and the refrigerant in the first gas supply circuit; and / or,

[0097] When the outdoor ambient temperature is lower than the first preset temperature and the gas supply temperature is higher than the third preset temperature, the first phase change module is activated to exchange heat between the refrigerant in the indoor heat exchange branch and the refrigerant in the first gas supply circuit, and the second phase change module is activated to absorb heat from the refrigerant in the first gas supply circuit after heat exchange, wherein the third preset temperature is higher than the second preset temperature; and / or,

[0098] When the outdoor ambient temperature is greater than or equal to the first preset temperature, the first phase change module is activated to absorb heat from the refrigerant in the indoor heat exchange branch, and the second phase change module is activated to absorb heat from the refrigerant in the first gas replenishment circuit.

[0099] Specifically, the first preset temperature, the second preset temperature, and the third preset temperature can be set according to actual needs, and this application does not impose any specific limitations.

[0100] For example, assuming the first preset temperature is 10℃, the second preset temperature is 10℃, and the third preset temperature is 25℃, when the outdoor ambient temperature is less than 10℃ and the gas supply temperature is less than 10℃, the first phase change module can be activated to exchange heat between the refrigerant in the indoor heat exchange branch and the refrigerant in the first gas supply circuit. At this time, part of the high-temperature and high-pressure refrigerant discharged from the compressor outlet returns to the compressor outlet pipe through the first pipeline, while the other part enters the indoor heat exchanger through the oil separator and the four-way reversing valve for condensation and heat release to supply heat to the room. Then, part of the refrigerant output from the indoor heat exchanger can enter the outdoor heat exchanger through the third phase change module, absorb heat from the outdoor air, evaporate into gas, and then return to the compressor suction port through the four-way reversing valve and the gas-liquid separator. The other part of the refrigerant output from the indoor heat exchanger can enter the second pipeline through the subcooler, and then enter the compressor's gas supply port through the second pipeline. In this way, when the high-temperature, high-pressure refrigerant flows through the first pipeline, it absorbs and stores the heat from the high-temperature, high-pressure refrigerant through the first phase change module. When the low-temperature, low-pressure refrigerant, after heat exchange in the room, flows through the second pipeline, it releases the previously stored heat through the first phase change module, thereby raising the temperature of the refrigerant that provides enthalpy enhancement. This reduces the risk of liquid slugging caused by refrigerant carrying liquid in the first gas injection circuit under low-temperature conditions, and also reduces compressor power consumption fluctuations while ensuring the reliability of the multi-split air conditioning unit.

[0101] When the outdoor ambient temperature is below 10℃ and the gas injection temperature is above 25℃, the first phase change module can be activated to exchange heat between the refrigerant in the indoor heat exchange branch and the refrigerant in the first gas injection circuit. Simultaneously, the second phase change module can be activated to absorb heat from the refrigerant in the first gas injection circuit after heat exchange. At this time, the refrigerant heated by the first phase change module can bypass the direct flow from the second pipeline into the compressor's gas injection port, instead flowing through the third pipeline, absorbing heat from the second phase change module, and then into the compressor's gas injection port. This allows the second phase change module to dynamically absorb or release heat, balancing the superheat and subcooling of the refrigerant in the first gas injection circuit, suppressing compressor frequency fluctuations caused by sudden load changes, and improving the unit's operational stability and energy efficiency consistency.

[0102] When the outdoor ambient temperature is greater than or equal to 10℃, the first phase change module can be activated to absorb heat from the refrigerant in the indoor heat exchange branch, and the second phase change module can be activated to absorb heat from the refrigerant in the first gas replenishment circuit. In this way, heat can be dynamically absorbed by the first and second phase change modules to prevent excessive overheating of the refrigerant in the first gas replenishment circuit, and it can also be used to release heat at low temperatures, thereby improving the overall energy efficiency of the unit.

[0103] In this way, the operating status of the first phase change module and the second phase change module can be flexibly controlled according to the outdoor ambient temperature and the gas supply temperature, thereby improving the unit's adaptability to all scenarios.

[0104] In an optional embodiment, the method further includes:

[0105] Obtain the operating mode of the multi-split air conditioning unit;

[0106] The operating status of the third phase change module is controlled according to the working mode of the multi-split air conditioning unit.

[0107] Specifically, the operating modes of the aforementioned multi-split air conditioning units may include, but are not limited to, heating mode, cooling mode, and defrosting mode. These modes can be determined by analyzing the operating status of the multi-split air conditioning units or by analyzing the received user instructions. This application does not impose any specific limitations on these modes.

[0108] In this way, the working status of the third phase change module can be controlled according to the working mode of the multi-split air conditioning unit, thereby realizing the absorption and release of heat by the refrigerant in the outdoor heat exchange branch, thus breaking through the application limitations of single-stage phase change materials and significantly improving the overall performance of the unit.

[0109] In an optional embodiment, step S302, controlling the operating state of the third phase change module according to the operating mode of the multi-split air conditioning unit, includes:

[0110] When the multi-split air conditioning unit is operating in heating mode, the third phase change module is activated to absorb heat from the refrigerant after heat exchange in the indoor heat exchange branch; and / or,

[0111] When the multi-split air conditioning unit is operating in defrost mode, the third phase change module is activated to release heat from the refrigerant after heat exchange in the outdoor heat exchange branch; and / or,

[0112] When the multi-split air conditioning unit is in cooling mode, the third phase change module is activated to absorb heat from the refrigerant after heat exchange in the outdoor heat exchange branch.

[0113] In this way, during winter heating, the third phase change module of the multi-split air conditioning unit can absorb the waste heat from the piping during the heating process. During defrosting, the four-way reversing valve reverses, allowing the high-temperature, high-pressure refrigerant gas from the compressor to enter the outdoor heat exchanger via the four-way reversing valve, where it condenses and releases heat. This released heat is used for defrosting. After passing through the electronic expansion valve and becoming a low-temperature, low-pressure liquid, it then enters the third phase change module again to absorb heat from the phase change material and evaporates back into gas. Finally, it returns to the compressor's suction port via the electronic expansion valve, the indoor heat exchanger, and the gas-liquid separator. During defrosting, the third phase change module acts as a low-grade heat source, providing sufficient heat for the defrosting process and increasing the defrosting speed. During summer cooling, the third phase change module can absorb the heat from the refrigerant flowing out of the outdoor heat exchanger, pre-subcooling it before the subcooler to achieve bipolar subcooling, greatly improving the subcooling degree during cooling and thus significantly enhancing the unit's performance.

[0114] The multi-split air conditioning unit and its control method provided in this application can achieve the following technical effects:

[0115] 1. Elimination of risk of liquid refrigerant in the gas-filled refrigerant and improvement of heating reliability: By storing the waste heat of the compressor exhaust through a high-temperature phase change module, the low-temperature gas-filled refrigerant is preheated to a safe superheat level, which completely avoids liquid refrigerant entering the compressor and significantly improves heating efficiency and compressor operation reliability.

[0116] 2. Dynamic and precise adjustment of refrigerant replenishment status under normal operating conditions: The medium-temperature phase change module is embedded in the first refrigerant replenishment circuit. It balances the superheat and subcooling of the refrigerant in real time through phase change heat absorption or release, suppresses compressor frequency fluctuations caused by sudden load changes, and improves the unit's operational stability and energy efficiency consistency.

[0117] 3. Optimized defrosting efficiency and enhanced indoor temperature control stability: The low-temperature phase change module absorbs the waste heat from the pipeline during the heating process and releases the heat during the defrosting process, thereby increasing the refrigerant temperature, shortening the defrosting cycle, and solving the problems of temperature drop fluctuations and duration caused by traditional defrosting.

[0118] 4. Wide temperature range and multi-condition dynamic adaptation and energy efficiency leap: The three-stage phase change modules of high, medium and low temperature work together to cover extreme cooling and heating scenarios, accurately adjust the gas supply state, break the limitations of single-stage phase change materials, and achieve a leap in unit energy efficiency stability and comprehensive performance.

[0119] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the control method for a multi-split air conditioning unit as provided in any of the foregoing method embodiments.

[0120] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0121] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0122] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0123] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A multi-split air conditioning unit, characterized in that, The multi-split air conditioning unit includes: a compressor, a subcooler, a first phase change module, a second phase change module, an indoor heat exchange branch, a first gas supply circuit, a control unit, and multiple switching units; The indoor heat exchange branch is located between the exhaust port of the compressor and the first port of the subcooler, and the first gas supply circuit is located between the second port of the subcooler and the gas supply port of the compressor. The first phase change module is coupled to the indoor heat exchange branch and the first gas supply circuit, and the second phase change module is embedded in the first gas supply circuit; The plurality of switching units are disposed on the indoor heat exchange branch and the first gas supply circuit, and the plurality of switching units are electrically connected to the control unit.

2. The multi-split air conditioning unit according to claim 1, characterized in that, The indoor heat exchange branch includes a first pipeline, the first air supply circuit includes a second pipeline, and the plurality of switching units include a first switching unit, a second switching unit, and a third switching unit; Wherein, the first end of the first pipeline is connected to the first connection point on the indoor heat exchange branch, and the second end of the first pipeline is connected to the second connection point on the indoor heat exchange branch. Both the first connection point and the second connection point are located downstream of the compressor's exhaust port. The first end of the second pipeline is connected to the second port of the subcooler, and the second end of the second pipeline is connected to the gas supply port of the compressor. The first phase change module is coupled to the first pipeline and the second pipeline, the first switch unit is disposed on the first pipeline, and the second switch unit and the third switch unit are disposed on the second pipeline, with the second switch unit and the third switch unit located upstream and downstream of the first phase change module, respectively.

3. The multi-split air conditioning unit according to claim 2, characterized in that, The first gas replenishment circuit also includes a third pipeline, and the plurality of switching units also include a fourth switching unit; Wherein, the first end of the third pipeline is connected to the third connection point on the second pipeline, and the second end of the third pipeline is connected to the fourth connection point on the second pipeline. The third connection point and the fourth connection point are located upstream and downstream of the third switch unit, respectively. Both the second phase change module and the fourth switching unit are disposed on the third pipeline.

4. The multi-split air conditioning unit according to claim 3, characterized in that, The first gas replenishment circuit also includes a fourth pipeline, and the plurality of switching units also include a fifth switching unit; Wherein, the first end of the fourth pipeline is connected to the second port of the subcooler, and the second end of the fourth pipeline is connected to the fifth connection point on the third pipeline. The fifth connection point is located between the second phase change module and the fourth switching unit. The fifth switch unit is disposed on the third pipeline.

5. The multi-split air conditioning unit according to claim 1, characterized in that, The multi-split air conditioning unit also includes a third phase change module and an outdoor heat exchange branch; wherein, the outdoor heat exchange branch is located between the third port of the subcooler and the suction port of the compressor, and the third phase change module is embedded in the outdoor heat exchange branch.

6. The multi-split air conditioning unit according to claim 5, characterized in that, The multi-split air conditioning unit also includes an outdoor heat exchanger and a gas-liquid separator, and the outdoor heat exchange branch includes a fifth pipe, a sixth pipe and a seventh pipe; Wherein, the first end of the fifth pipe is connected to the third port of the subcooler, and the second end of the fifth pipe is connected to the first port of the outdoor heat exchanger; The first end of the sixth pipeline is connected to the second port of the outdoor heat exchanger, and the second end of the sixth pipeline is connected to the air intake of the gas-liquid separator. The first end of the seventh pipeline is connected to the exhaust port of the gas-liquid separator, and the second end of the seventh pipeline is connected to the suction port of the compressor. The third phase change module is embedded in the fifth pipeline.

7. The multi-split air conditioning unit according to claim 6, characterized in that, The multi-split air conditioning unit also includes a second gas supply circuit, and the plurality of switching units also include a sixth switching unit; The second gas replenishment circuit is located between the second port of the subcooler and the gas replenishment port of the gas-liquid separator. The sixth switch unit is located on the second gas supply circuit.

8. The multi-split air conditioning unit according to claim 5, characterized in that, The phase change material selected for the first phase change module is erythritol, the phase change material selected for the second phase change module is modified paraffin, and the phase change material selected for the third phase change module is calcium chloride hexahydrate solution.

9. The multi-split air conditioning unit according to claim 8, characterized in that, The phase transition temperature of the first phase transition module is 50°C to 70°C, the phase transition temperature of the second phase transition module is 20°C to 50°C, and the phase transition temperature of the third phase transition module is -20°C to 20°C.

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