Air conditioning system and control method thereof

Abstract

The invention relates to the technical field of air conditioning systems, particularly provides an air conditioning system and a control method thereof, and aims to solve the problem that an existing air conditioning system cannot dehumidify while heating. The air conditioning system comprises a refrigerant circulation loop, and a compressor, an indoor heat exchanger and an outdoor heat exchanger which are arranged on the refrigerant circulation loop; wherein the indoor heat exchanger comprises a first heat exchange part and a second heat exchange part which are provided with independent passages, the first heat exchange part is connected with the refrigerant circulation loop through a first shunting pipeline, and the second heat exchange part is connected with the refrigerant circulation loop through a second shunting pipeline; the air conditioning system further comprises a shunting branch, the two ends of the shunting branch are connected with the second shunting pipeline, a branch expansion valve and a three-way valve are arranged on the shunting branch, and the three-way valve is connected with the shunting branch, the second shunting pipeline and the refrigerant circulation loop. According to the heat exchanger capable of achieving reheating dehumidification through variable shunting of the air conditioning system, reheating dehumidification can be achieved under the condition that normal refrigerating and heating are not affected.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning systems, and specifically provides an air conditioning system and a control method thereof. Background Art

[0002] With the development of smart homes, the design of air conditioners is more energy-saving and environmentally friendly, and user needs are also developing in a diversified direction. In winter, the room temperature is low, and air conditioning is generally used to heat the room. However, in real life, especially in southern regions, the humidity is high in winter. In order to ensure comfort, an additional dehumidifier is needed to dehumidify the room while the air conditioner is heating, which makes the cost higher.

[0003] Accordingly, the art needs a new air conditioning system to solve the problem that the existing air conditioning system cannot dehumidify while heating. Summary of the invention

[0004] The present invention aims to solve the above technical problem, that is, to solve the problem that the existing air-conditioning system cannot dehumidify while heating.

[0005] The present invention provides an air conditioning system, comprising a refrigerant circulation loop, and a compressor, an indoor heat exchanger, and an outdoor heat exchanger arranged on the refrigerant circulation loop; wherein the indoor heat exchanger comprises a first heat exchange part and a second heat exchange part having independent passages, the first heat exchange part is connected to the refrigerant circulation loop through a first shunt pipeline, and the second heat exchange part is connected to the refrigerant circulation loop through a second shunt pipeline;

[0006] The air conditioning system also includes a shunt branch, both ends of which are connected to the second shunt pipeline. A branch expansion valve and a three-way valve are provided on the shunt branch, and the three-way valve is respectively connected to the shunt branch, the second shunt pipeline and the refrigerant circulation loop.

[0007] In the case of adopting the above technical solution, the heat exchanger of the present invention that realizes reheat dehumidification with variable shunt can realize reheat dehumidification without affecting normal cooling and heating. When realizing the reheat dehumidification function, in order to keep the indoor temperature from decreasing and dehumidify the indoor temperature at the same time, the three-way valve is switched to connect the shunt branch with the refrigerant circulation loop. A part of the refrigerant at the compressor outlet enters the first heat exchange part from the first shunt pipeline for normal heat exchange, and the other part of the refrigerant enters the second heat exchange part from the shunt branch. After throttling at the branch expansion valve, a certain saturated refrigerant is formed, and then enters the second heat exchange part. The refrigerant evaporates and absorbs heat in the second heat exchange part, and the high-humidity air generates condensed water when it encounters cold, and is finally discharged from the indoor unit to achieve the dehumidification effect.

[0008] In an optional technical solution of the above-mentioned air-conditioning system, the refrigerant inlet ends of the first branch pipeline and the second branch pipeline are merged into a refrigerant main inlet pipe, and the refrigerant outlet ends of the first branch pipeline and the second branch pipeline are merged into a refrigerant main outlet pipe, and the refrigerant main inlet pipe and the refrigerant main outlet pipe are respectively connected to the refrigerant circulation loop.

[0009] When the above technical solution is adopted, the two ends of the first shunt pipeline and the second shunt pipeline are combined into one inlet pipe and one outlet pipe, thereby simplifying the pipeline.

[0010] In an optional technical solution of the above air-conditioning system, the second heat exchange part is arranged above the first heat exchange part.

[0011] When the above technical solution is adopted, the second heat exchange part is arranged above the first heat exchange part, so that when the reheat dehumidification function is running, there is no risk of condensation and water blowing when the cold air above meets the hot air below.

[0012] In an optional technical solution of the control method of the above air-conditioning system, the control method includes:

[0013] The control method comprises:

[0014] Receiving an instruction to operate the reheat dehumidification function;

[0015] Running the reheat dehumidification function;

[0016] The steps of operating the reheat dehumidification function include:

[0017] The three-way valve is controlled to switch to connect the diversion branch with the refrigerant circulation circuit.

[0018] In the case of adopting the above technical solution, the air-conditioning system of the present invention operates the reheat dehumidification function in order to ensure that the indoor temperature does not decrease and the dehumidification is effective. When the air conditioner operates the reheat dehumidification function, the three-way valve switches to the shunt branch and is connected to the refrigerant circulation loop. The refrigerant entering the indoor heat exchanger is divided into two routes. One route enters the first heat exchange part from the first shunt pipeline to condense and dissipate heat to heat the room. The other route enters the second heat exchange part from the shunt branch. Before entering the second heat exchange part, the refrigerant is throttled by the branch expansion valve. After throttling, the refrigerant will form a certain saturated refrigerant. When entering the second heat exchange part, it is no longer condensation heat dissipation but evaporation heat absorption. The saturated high-humidity air in the room will produce condensed water when it encounters cold, and then discharged from the indoor unit, so as to achieve the purpose of not lowering the indoor temperature and realize the effect of constant temperature dehumidification.

[0019] In the optional technical solution of the control method of the air conditioning system, the step of "running the reheat dehumidification function" further includes:

[0020] Obtain the indoor environmental humidity H and the compressor operating frequency Hz;

[0021] Calculate the opening value of the branch expansion valve according to the calculation formula; wherein, the opening value of the branch expansion valve = a*Hz - b(H - H 0) , where a and b are conventional coefficients, and H0 is the set target humidity value;

[0022] Adjust the opening of the branch expansion valve according to the calculated opening value of the branch expansion valve.

[0023] In the case of adopting the above technical solution, according to the opening formula of the branch expansion valve, the greater the humidity, the smaller the opening of the branch expansion valve, so that the humidity can be quickly reduced to make the humidity close to the target humidity value. The control method of the air-conditioning system of the present invention can achieve the reheating and dehumidification effect of the indoor environment by adjusting the opening of the branch expansion valve, achieve the purpose of not reducing the indoor temperature, and achieve the effect of constant-temperature dehumidification in the room.

[0024] In an alternative technical solution of the above control method of the air-conditioning system, after the step of "receiving an instruction to operate the reheating and dehumidification function" and before the step of "operating the reheating and dehumidification function", the control method includes:

[0025] Obtain the indoor environmental temperature T_env and the set temperature T_set;

[0026] If T_env - T_set > the first preset temperature, the compressor operates at an increased first frequency value on the basis of the set frequency;

[0027] If the first preset temperature ≥ T_env - T_set ≥ the second preset temperature, the compressor operates at an increased second frequency value on the basis of the set frequency; the first frequency value > the second frequency value.

[0028] In the case of adopting the above technical solution, when the air conditioner starts to operate, if the difference between T_set and T_env is greater than the first preset temperature, it means that the indoor environmental temperature is very low and the gap with the set temperature is large, then the compressor frequency is greatly increased on the basis of the set frequency to quickly heat up the room. When the difference between T_set and T_env is between the first preset temperature and the second preset temperature, the compressor frequency can be appropriately reduced for high-frequency operation.

[0029] In an alternative technical solution of the above control method of the air-conditioning system, after the step of "receiving an instruction to operate the reheating and dehumidification function" and before the step of "operating the reheating and dehumidification function", the control method includes:

[0030] If T_set - T_env < the second preset temperature, then control the compressor to operate at the set frequency.

[0031] When adopting the above technical solution, if the difference between Tset and Tring is less than the second preset temperature, it means that the difference between the indoor ambient temperature and the set temperature is not large, and the air-conditioning system operates at the set frequency without up-frequency operation.

[0032] In the optional technical solution of the control method of the above air-conditioning system, after the step of "receiving an instruction to operate the reheat dehumidification function", the control method includes:

[0033] When T ring - T setting ≤ the first preset temperature and H>the first preset humidity, the air conditioning system is controlled to operate the reheat dehumidification function.

[0034] In the case of adopting the above technical solution, if the indoor relative humidity is greater than the first preset humidity, indicating that the indoor humidity is high, the reheat dehumidification function is operated to ensure the indoor temperature and reduce the indoor humidity. On the contrary, if the indoor humidity is lower than the first preset humidity, the reheat dehumidification function is not operated.

[0035] In the optional technical solution of the control method of the air-conditioning system, after the step of "running the reheat dehumidification function", the control method further includes:

[0036] When the third preset humidity ≥ H ≥ the second preset humidity, the reheat dehumidification function is turned off;

[0037] When H≥the fourth preset humidity, the reheat dehumidification function is turned on;

[0038] When H≤fifth preset humidity, the reheat dehumidification function is turned off; wherein, the fifth preset humidity<second preset humidity<third preset humidity<fourth preset humidity<first preset humidity;

[0039] The steps to turn off the reheat dehumidification function include:

[0040] The three-way valve is controlled to switch to connect the second flow diversion pipeline with the refrigerant circulation circuit.

[0041] In the case of adopting the above technical solution, when the indoor humidity is between the second preset humidity and the third preset humidity, it means that the indoor humidity is relatively suitable, so the reheat dehumidification function is turned off and conventional heating is operated. When the indoor humidity is higher than the fourth preset humidity, it means that the indoor humidity is high, so the reheat dehumidification function is turned on. When the indoor humidity is lower than the fifth preset humidity, it means that the indoor humidity is low, and the reheat dehumidification function is turned off.

[0042] In an optional technical solution of the control method of the air conditioning system, the control method further includes:

[0043] If the fourth preset temperature ≥ Tset-Tring ≥ the third preset temperature, the compressor is controlled to stop;

[0044] After the step of "when the fourth preset temperature ≥ Tset - Troom ≥ the third preset temperature, control the compressor to stop", the control method further includes:

[0045] When Troom - Tset < the third preset temperature, reduce the compressor frequency until the minimum frequency; wherein, the third preset temperature < the second preset temperature;

[0046] When Troom - Tset > the fourth preset temperature, increase the compressor frequency until the set frequency; wherein, the fourth preset temperature < the first preset temperature.

[0047] In the case of adopting the above technical solution, after the air-conditioning system operates at a high frequency for a period of time at the initial stage of operation, as the indoor temperature gradually rises, the operation of the air-conditioning system tends to be stable, and the indoor temperature and the set temperature tend to be consistent. Until Tset - Troom remains within a certain temperature range, the high-frequency operation can be stopped. During the stable operation period, Tset - Troom remains between the third preset temperature and the fourth preset temperature. Once it exceeds this temperature range, the low-frequency operation is adjusted to maintain heating.

[0048] Those skilled in the art can understand that the air-conditioning system of the present invention includes a refrigerant circulation circuit, and a compressor, an indoor heat exchanger, and an outdoor heat exchanger provided on the refrigerant circulation circuit; wherein, the indoor heat exchanger includes a first heat exchange part and a second heat exchange part with independent passages. The first heat exchange part is connected to the refrigerant circulation circuit through a first shunt pipeline, and the second heat exchange part is connected to the refrigerant circulation circuit through a second shunt pipeline; the air-conditioning system further includes a shunt branch. Both ends of the shunt branch are connected to the second shunt pipeline. A branch expansion valve and a three-way valve are provided on the shunt branch. The three-way valve is respectively connected to the shunt branch, the second shunt pipeline, and the refrigerant circulation circuit.

[0049] In the case of adopting the above technical solution, the variable-shunt heat exchanger for reheating and dehumidifying of the present invention can realize reheating and dehumidifying without affecting normal refrigeration and heating. When realizing the reheating and dehumidifying function, in order to keep the indoor temperature from decreasing and dehumidify the indoor air at the same time, the three-way valve is switched to connect the shunt branch and the refrigerant circulation circuit. The first part of the refrigerant at the compressor outlet enters the first heat exchange part through the first shunt pipeline for normal heat exchange. Before the other part of the refrigerant enters the second heat exchange part from the shunt branch, it is throttled at the branch expansion valve to form a certain saturated state refrigerant, and then enters the second heat exchange part. The refrigerant evaporates and absorbs heat in the second heat exchange part, and the high-humidity air is cooled to generate condensed water, which is finally discharged from the indoor unit to achieve the dehumidifying effect. Description of the Drawings

[0050] The following describes the preferred embodiments of the present invention with reference to the drawings, in which:

[0051] Figure 1 is a schematic diagram of the refrigerant flow direction when the air-conditioning system of the present invention operates in the heating mode;

[0052] Figure 2 It is a schematic diagram of the refrigerant flow direction when the air conditioning system of the present invention operates the reheat dehumidification function;

[0053] Figure 3 is a schematic structural diagram of an indoor heat exchanger of the present invention;

[0054] Figure 4 is a flow chart of the main steps of the control method of the air conditioning system of the present invention;

[0055] Figure 5 is a flowchart of steps of an implementation method of a control method of an air conditioning system of the present invention;

[0056] Figure 6 It is a flowchart of specific steps of an implementation method of the air conditioning system control method of the present invention.

[0057] List of reference numerals:

[0058] 1. Compressor; 2. Four-way valve; 3. Indoor heat exchanger; 31. First heat exchange unit; 311. First bypass pipeline; 32. Second heat exchange unit; 321. Second bypass pipeline; 33. Third heat exchange unit; 331. Third bypass pipeline; 4. Main expansion valve; 5. Outdoor heat exchanger; 6. Branch; 61. Three-way valve; 62. Branch expansion valve; 7. Refrigerant circulation loop. DETAILED DESCRIPTION

[0059] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0060] It should be noted that in the description of the present invention, the terms "upper", "lower", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0061] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] Reference Figure 1 and Figure 3 The air conditioning system of the present invention comprises a refrigerant circulation loop 7, and a compressor 1, a four-way valve 2, an indoor heat exchanger 3, a main expansion valve 4 and an outdoor heat exchanger 5 which are sequentially arranged on the refrigerant circulation loop 7. Figure 1 and Figure 3 , wherein the indoor heat exchanger 3 includes a first heat exchange part 31, a second heat exchange part 32 and a third heat exchange part 33 with independent passages. The first heat exchange part 31 is connected to the refrigerant circulation loop 7 through a first shunt pipe 311. The second heat exchange part 32 is connected to the refrigerant circulation loop 7 through a second shunt pipe 321. The third heat exchange part 33 is connected to the refrigerant circulation loop 7 through a third shunt pipe 331.

[0063] The air conditioning system further includes a shunt branch 6, both ends of which are respectively connected to the second shunt pipeline 321. The shunt branch 6 is provided with a branch expansion valve 62 and a three-way valve 61. The three-way valve 61 is respectively connected to the shunt branch 6, the second shunt pipeline 321 and the refrigerant circulation loop 7.

[0064] Furthermore, the refrigerant inlet ends of the first shunt pipeline 311, the second shunt pipeline 321 and the third shunt pipeline 331 are combined into a refrigerant main inlet pipe, and the refrigerant outlet ends of the first shunt pipeline 311, the second shunt pipeline 321 and the third shunt pipeline 331 are combined into a refrigerant main outlet pipe. The refrigerant main inlet pipe and the refrigerant main outlet pipe are respectively connected to the refrigerant circulation loop 7. The second heat exchange part 32 is arranged above the first heat exchange part 31, so that when the reheat dehumidification function is running, the cold air above meets the hot air below without the risk of condensation and water blowing.

[0065] The heat exchanger of the present invention that realizes reheat dehumidification by variable shunt can realize reheat dehumidification without affecting normal cooling and heating. Specifically, during conventional cooling, the three-way valve 61 is switched to the AB end connection, that is, the second shunt pipeline 321 is connected to the refrigerant circulation loop 7. The refrigerant at the outlet of the compressor 1 enters the first heat exchange part 31, the second heat exchange part 32 and the third heat exchange part 33 on the indoor side after throttling from the outdoor heat exchanger 5, and after evaporation and heat absorption, the refrigerant returns to the compressor 1, and the cycle repeats.

[0066] Reference Figure 1 In normal heating, the three-way valve 61 is switched to the AB end connection, that is, the second flow bypass pipe 321 is connected to the refrigerant circulation loop 7. The high-temperature and high-pressure refrigerant goes directly from the compressor 1 to the first heat exchange part 31, the second heat exchange part 32 and the third heat exchange part 33 on the indoor side, condenses and dissipates heat in the indoor heat exchanger, then enters the outdoor heat exchanger through throttling, and enters the compressor 1 after heat exchange in the outdoor heat exchanger 5, and the cycle repeats.

[0067] Reference Figure 2 When the reheat dehumidification function is realized, in order to keep the indoor temperature from decreasing and dehumidify the indoor temperature at the same time, the three-way valve 61 is switched to the AC end connection, that is, the shunt branch 6 and the refrigerant circulation loop 7 are connected. The first part of the refrigerant at the outlet of the compressor 1 enters the first heat exchange part 331 from the first shunt pipeline 311 for normal heat exchange, and the second part enters the third heat exchange part 33 from the third shunt pipeline 331 for normal heat exchange to condense and dissipate heat indoors. Before the third part of the refrigerant enters the second heat exchange part 32 from the shunt branch 6, it is throttled at the branch expansion valve 62 to form a certain saturated refrigerant, and then enters the second heat exchange part 32. The refrigerant evaporates and absorbs heat in the second heat exchange part 32, and the high-humidity air is cooled to produce condensed water, which is finally discharged from the indoor unit to achieve the dehumidification effect.

[0068] Reference Figure 4 In a possible implementation manner, a control method for an air conditioning system is also provided, and the control method comprises the following main steps:

[0069] Step S10: receiving an instruction to operate the reheat dehumidification function;

[0070] Step S20: running the reheat dehumidification function;

[0071] The steps of operating the reheat dehumidification function include: controlling the three-way valve to switch to connect the diversion branch and the refrigerant circulation circuit.

[0072] When the air conditioning system of the present invention needs to heat and dehumidify the room at the same time, in order to ensure that the indoor temperature does not drop and the dehumidification is effective, the reheat dehumidification function is operated. When the air conditioner operates the reheat dehumidification function, the three-way valve 61 is switched to the AC end to connect, so that the shunt branch 6 and the refrigerant circulation loop 7 are connected. The refrigerant entering the indoor heat exchanger 3 is divided into three paths. The first path enters the first heat exchange part 31 from the first shunt pipe 311 to condense and dissipate heat, the second path enters the second heat exchange part 32 from the shunt branch 6 to evaporate and absorb heat, and the third path enters the third heat exchange part 33 from the third shunt pipe 331 to condense and dissipate heat. Before entering the second heat exchange part 32, the refrigerant is throttled by the electronic branch expansion valve 62. After throttling, the refrigerant will form a certain saturated refrigerant. When entering the second heat exchange part 32, it is no longer condensed and dissipated but evaporated and absorbed heat. The saturated high-humidity air in the room will produce condensed water when it encounters cold, and then discharged from the indoor unit, so as to achieve the purpose of not lowering the indoor temperature and realize the effect of constant temperature dehumidification.

[0073] Reference Figure 5 Further, in a possible implementation manner, the control method of the present invention includes the following specific steps:

[0074] Step S11: the air conditioning system operates in heating mode;

[0075] Step S12: receiving an instruction to operate the reheat dehumidification function;

[0076] Step S13: Detecting the indoor environment temperature Tring, the set temperature Tset and the indoor environment humidity H;

[0077] Step S14: adjusting the operating frequency of the compressor according to the difference between Tset and Tring.

[0078] Specifically, step S14 further includes:

[0079] Steps: When Tset-Tring>first set temperature, the compressor is controlled to increase the first frequency value based on the set frequency.

[0080] The first frequency value is set to 5Hz, and the first preset temperature is set to 8℃. When the air conditioner starts to run, if the difference between Tset and Tring is greater than 8℃, it means that the indoor ambient temperature is very low and the difference between it and the set temperature is large. In this case, the compressor frequency will be greatly increased based on the set frequency to quickly heat up the room, and the reheat dehumidification function will not be started temporarily.

[0081] Step S14 further includes:

[0082] Step: When the second preset temperature ≤ Tset-Tring ≤ the first preset temperature, the compressor 1 is controlled to increase the second frequency value to operate on the basis of the set frequency.

[0083] The second preset temperature is set to 5°C, and the second frequency value is set to 3Hz. If the difference between Tset and Tring is between 5°C and 8°C, the compressor frequency is slightly increased based on the set frequency to quickly heat up the room.

[0084] Step S14 further includes:

[0085] Steps: When Tset-Tring < the second preset temperature, the compressor is controlled to run at the set frequency.

[0086] If the difference between Tset and Tring is less than 5°C, it means that the gap between the indoor ambient temperature and the set temperature is not large, and the air-conditioning system operates at the set frequency.

[0087] After step S14, the control method further includes:

[0088] Step: If the fourth preset temperature ≥ Tset-Tring ≥ the third preset temperature, the compressor is controlled to stop.

[0089] After the air conditioning system runs at high frequency for a period of time at the beginning of operation, as the indoor temperature gradually rises, the air conditioning system operation tends to be stable, and the indoor temperature and the set temperature tend to be consistent. The high-frequency operation can be stopped until the T-set-T loop remains within a certain temperature range.

[0090] For example, after the air conditioning system runs at high frequency, it enters the stable operation period, and the T setting-T ring is maintained between the third preset temperature and the fourth preset temperature. Once the temperature range is exceeded, the low frequency operation is performed to maintain heating. The third preset temperature is set to -2°C, and the fourth preset temperature is set to 2°C.

[0091] Specifically, the steps are: Tset-Tring<the third preset temperature, then reducing the compressor frequency to the lowest compressor frequency;

[0092] Steps: Tset-Tring>the fourth preset temperature, then increase the compressor frequency to the set frequency.

[0093] During stable operation of the air conditioning system, if the difference between T set and T ring is less than -2°C, the compressor frequency is reduced to the minimum compressor frequency. If the difference between T set and T ring is greater than 2°C, the compressor frequency is increased to the set compressor frequency. Thus, the compressor 1 is kept at a lower frequency, and the difference between the indoor temperature and the set temperature is kept at a comfortable state between -2°C and 2°C.

[0094] The minimum compressor frequency and the set compressor frequency can be set by technical personnel in this field according to actual needs. The present invention does not impose any restrictions on the specific values ​​of the minimum compressor frequency and the set compressor frequency, and they all fall within the protection scope of the present invention.

[0095] After receiving the instruction to operate the reheat dehumidification function from the user, in the initial operation of the air-conditioning system, if the indoor temperature is low, in order to ensure the heating amount, the reheat dehumidification function will be turned on when Tset-Tring≤8 and the indoor humidity is higher than a certain value.

[0096] Reference Figure 5 and Figure 6 Specifically, the control method further includes:

[0097] Step S21: When Tset-Tring≤first preset temperature and H>first preset humidity, the air conditioning system is controlled to operate the reheat dehumidification function.

[0098] The first preset humidity is set to 70%. If the indoor relative humidity is greater than 70%, indicating that both the indoor humidity and temperature are high, the reheat dehumidification function is run to ensure the indoor temperature and reduce the indoor humidity. On the contrary, if the indoor humidity is lower than 70%, the reheat dehumidification function is not run.

[0099] The steps of "operating the reheat dehumidification function" further include:

[0100] Step S211: Control the three-way valve to switch to connect the flow branch and the refrigerant circulation circuit;

[0101] Step S212: Calculate the branch expansion valve opening according to the calculation formula; branch expansion valve opening value = a*Hz-b(H-H0), where a and b are conventional coefficients, Hz is the compressor frequency, and H0 is the target humidity value;

[0102] Step S213: adjusting the branch expansion valve opening according to the calculated branch expansion valve opening value.

[0103] Among them, the conventional coefficient a and the conventional coefficient b are calculated based on multiple groups of experimental data. According to the branch expansion valve opening formula, the greater the humidity, the smaller the opening of the branch expansion valve 62, so that the humidity can be quickly reduced to make the humidity close to the target humidity value. Optionally, the optimal humidity value H0 in this embodiment is set to 45%. The branch expansion valve opening value varies between 0% and 100%. The control method of the air-conditioning system of the present invention can achieve the reheating and dehumidification effect of the indoor environment by adjusting the opening of the branch expansion valve 62, so as to achieve the purpose of not lowering the indoor temperature and achieving the effect of indoor constant temperature dehumidification. However, it should be noted that the specific numerical value of the target humidity value H0 can be set by those skilled in the art, and all fall within the protection scope of the present invention.

[0104] Reference Figure 5 After the step of “operating the reheat dehumidification function”, the control method further includes:

[0105] Step S15: When the third preset humidity ≥ indoor humidity ≥ second preset humidity, the reheat dehumidification function is turned off.

[0106] The second preset humidity is set to 40%, and the third preset humidity is set to 50%.

[0107] When the indoor humidity is between the second preset humidity and the third preset humidity, it indicates that the indoor humidity is relatively suitable, so the reheat dehumidification function is turned off and conventional heating is operated.

[0108] Step S16: when the indoor humidity is ≥ the fourth preset humidity, the reheat dehumidification function is turned on;

[0109] Step S17: When the indoor humidity is less than or equal to the fifth preset humidity, the reheat dehumidification function is turned off.

[0110] The fourth preset humidity is set to 55%, and the fifth preset humidity is set to 35%.

[0111] The fifth preset humidity is less than the second preset humidity and less than the third preset humidity and less than the fourth preset humidity and less than the first preset humidity. When the indoor humidity is higher than the fourth preset humidity, it indicates that the indoor humidity is high, and the reheat dehumidification function is turned on. When the indoor humidity is lower than the fifth preset humidity, it indicates that the indoor humidity is low, and the reheat dehumidification function is turned off.

[0112] The steps to turn off the reheat dehumidification function include:

[0113] Steps: Control the three-way valve to switch the second diversion pipeline to connect with the refrigerant circulation circuit.

[0114] After turning off the hot dehumidification function, the heating mode is operated, and the three-way valve is switched to connect the AB ends, and the refrigerant enters the second heat exchange part 32 from the second bypass pipeline 321 to condense and dissipate heat.

[0115] It should be noted that although the specific values ​​of the preset temperature and preset humidity, etc. are exemplified in the above embodiment, it is not intended to impose any limitation on the above values. Those skilled in the art can set the above values ​​according to actual needs, and they all fall within the scope of protection of the present invention.

[0116] As stated in the first paragraph of this section, the above implementation mode is only used to illustrate the principles of the present invention and is not intended to limit the scope of protection of the present invention. Without departing from the principles of the present invention, those skilled in the art can adjust the above structure so that the present invention can be applied to more specific application scenarios.

[0117] Those skilled in the art can understand that the above-mentioned air conditioning system also includes some other well-known structures, the controller, the memory includes but is not limited to random access memory, flash memory, read-only memory, programmable read-only memory, volatile memory, non-volatile memory, serial memory, parallel memory or register, etc., and the processor includes but is not limited to CPLD / FPGA, DSP, ARM processor, MIPS processor, etc. In order to unnecessarily obscure the embodiments of the present disclosure, these well-known structures are not shown in the drawings.

[0118] Although the various steps in the above embodiment are described in the above order, those skilled in the art can understand that in order to achieve the effect of the present embodiment, different steps do not have to be executed in such an order, and they can be executed simultaneously (in parallel) or in a reverse order. For example, those skilled in the art can set the order of the steps as needed, and all of them fall within the protection scope of the present invention.

[0119] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. An air conditioning system, characterized in that: The air-conditioning system includes a refrigerant circulation circuit, a compressor, an indoor heat exchanger, and an outdoor heat exchanger provided on the refrigerant circulation circuit; wherein, the indoor heat exchanger includes a first heat exchange part and a second heat exchange part having independent passages, the first heat exchange part is connected to the refrigerant circulation circuit through a first shunt pipeline, and the second heat exchange part is connected to the refrigerant circulation circuit through a second shunt pipeline; The air-conditioning system further includes a shunt branch, both ends of the shunt branch are connected to the second shunt pipeline, a branch expansion valve and a three-way valve are provided on the shunt branch, and the three-way valve is respectively connected to the shunt branch, the second shunt pipeline and the refrigerant circulation circuit.

2. The air conditioning system according to claim 1, characterized in that: The refrigerant inlet ends of the first shunt pipeline and the second shunt pipeline are combined into a refrigerant total inlet pipe, the refrigerant outlet ends of the first shunt pipeline and the second shunt pipeline are combined into a refrigerant total outlet pipe, and the refrigerant total inlet pipe and the refrigerant total outlet pipe are respectively connected to the refrigerant circulation circuit.

3. The air conditioning system according to claim 1, characterized in that: The second heat exchange part is arranged above the first heat exchange part.

4. A control method for an air conditioning system, characterized in that: The control method includes: The control method includes: Receiving an instruction to operate the reheating and dehumidifying function; Operating the reheating and dehumidifying function; The steps of operating the reheating and dehumidifying function include: Controlling the three-way valve to switch to connect the shunt branch and the refrigerant circulation circuit.

5. The control method of the air conditioning system according to claim 4, characterized in that: The steps of "operating the reheating and dehumidifying function" further include: Obtaining the indoor environmental humidity H and the compressor operating frequency Hz; Calculating the opening value of the branch expansion valve according to a calculation formula; wherein, the opening value of the branch expansion valve = a*Hz - b(H - H0), where a and b are conventional coefficients, and H0 is the set target humidity value; Adjusting the opening of the branch expansion valve according to the calculated opening value of the branch expansion valve.

6. The control method of the air conditioning system according to claim 5, characterized in that: After the step of "receiving an instruction to operate the reheating and dehumidifying function" and before the step of "operating the reheating and dehumidifying function", the control method includes: Obtaining the indoor environmental temperature T_env and the set temperature T_set; If T_env - T_set > the first preset temperature, the compressor operates at an increased first frequency value on the basis of the set frequency; If the first preset temperature ≥ T_env - T_set ≥ the second preset temperature, the compressor operates at an increased second frequency value on the basis of the set frequency; the first frequency value > the second frequency value.

7. The control method of the air conditioning system according to claim 6, characterized in that: After the step of "receiving an instruction to operate the reheating and dehumidifying function" and before the step of "operating the reheating and dehumidifying function", the control method includes: When T_set - T_env < the second preset temperature, control the compressor to operate at the set frequency.

8. The control method of the air conditioning system according to claim 6, characterized in that: After the step of "receiving an instruction to operate the reheating and dehumidifying function", the control method includes: If T_env - T_set ≤ the first preset temperature and H > the first preset humidity, control the air-conditioning system to operate the reheating and dehumidifying function.

9. The control method of the air conditioning system according to claim 5, characterized in that: After the step of "operating the reheating and dehumidifying function", the control method further includes: When the third preset humidity ≥ H ≥ the second preset humidity, turn off the reheating and dehumidifying function; When H ≥ the fourth preset humidity, turn on the reheating and dehumidifying function; When H ≤ the fifth preset humidity, turn off the reheating and dehumidifying function; wherein, the fifth preset humidity < the second preset humidity < the third preset humidity < the fourth preset humidity < the first preset humidity; The steps of turning off the reheating and dehumidifying function include: Control the three-way valve to switch to communicate with the second shunt pipeline and the refrigerant circulation circuit.

10. The control method of the air conditioning system according to claim 6, characterized in that: The control method further includes: If the fourth preset temperature ≥ Tset - Tenv ≥ the third preset temperature, control the compressor to stop; After the step of "if the fourth preset temperature ≥ Tset - Tenv ≥ the third preset temperature, control the compressor to stop", the control method further includes: When Tenv - Tset < the third preset temperature, reduce the compressor frequency until the minimum frequency; wherein, the third preset temperature < the second preset temperature; When Tenv - Tset > the fourth preset temperature, increase the compressor frequency until the set frequency; wherein, the fourth preset temperature < the first preset temperature.

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