Central air conditioning

Abstract

The central air conditioner comprises a compressor, an outdoor heat exchanger, a throttling element and two indoor terminals each provided with two indoor heat exchangers, which can work in evaporation or condensation state; the controller has: a reheating dehumidification control part configured to make one indoor heat exchanger work in evaporation state and the other work in condensation state when receiving a reheating dehumidification instruction; a self-cleaning control part configured to make the two indoor heat exchangers work in evaporation state first and then in condensation state when receiving a self-cleaning instruction; an intervention control part configured to execute intervention control and start an auxiliary control element to execute the function compensation of the former when one of the reheating dehumidification control part and the self-cleaning control part is in working state, the corresponding control instruction of the other is received, and the corresponding target indoor terminal is different from the indoor terminal currently in working state. The application can overcome the contradiction between the reheating dehumidification and self-cleaning functions, and avoid the reduction of user experience caused by linear waiting time-sharing operation.

Description

[0001] This application is a divisional application of domestic application No. 202210575536.0, application date 2022-05-25, invention title: Central Air Conditioning. Technical Field

[0002] This invention relates to the field of air conditioning technology, and more particularly to a central air conditioning system. Background Technology

[0003] During cold, rainy weather, indoor humidity is high, further reducing the perceived temperature and causing poor human comfort. While air conditioning can reduce indoor humidity, the indoor heat exchanger operates in an evaporative state during dehumidification, further lowering the indoor temperature and exacerbating discomfort. To address this issue, existing technology designs and proposes air conditioners that dehumidify without lowering the temperature, incorporating a main heat exchanger and a secondary heat exchanger in the indoor air conditioning terminal. During low-temperature dehumidification, the main heat exchanger operates in an evaporative state, regulating indoor humidity; the secondary heat exchanger operates in a condensative state, compensating for indoor temperature fluctuations, resulting in a constant and dry outlet air temperature.

[0004] However, there is a inherent contradiction between dehumidification and self-cleaning functions, meaning they cannot operate simultaneously. Current technology addresses this by allowing one function to complete before the other can begin, which prolongs the user's waiting time and negatively impacts the user experience.

[0005] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0006] To address the contradiction between the lack of cooling and dehumidification functions and the self-cleaning function in existing technologies, which result in linear waiting and time-sharing operation, a central air conditioning system is designed and provided.

[0007] To achieve the above-mentioned objectives, the present invention employs the following technical solution:

[0008] In some embodiments of the present invention, a central air conditioning system includes: a compressor; an outdoor heat exchanger; a throttling element; and at least two indoor terminals, each indoor terminal having two indoor heat exchangers; the two indoor heat exchangers can operate in an evaporation state or a condensation state, respectively; and further includes: a controller having: a reheat dehumidification control unit configured to operate one indoor heat exchanger in one indoor terminal in an evaporation state and the other in a condensation state when receiving a reheat dehumidification command; a self-cleaning control unit configured to operate both indoor heat exchangers in one indoor terminal first in an evaporation state and then in a condensation state when receiving a self-cleaning command; and an intervention control unit configured to, when one of the reheat dehumidification control unit and the self-cleaning control unit is in operation and receives a control command corresponding to the other, and the target indoor terminal corresponding to the control command is different from the indoor terminal currently in operation, perform intervention control and activate an auxiliary control element in the indoor terminal currently in operation to perform functional compensation for the former.

[0009] In some embodiments of the present invention, the auxiliary control element is an auxiliary heating element disposed in the indoor terminal; the intervention control unit is configured to keep the reheat dehumidification control unit waiting and start the auxiliary heating element in the indoor terminal controlled by the reheat dehumidification control unit when the reheat dehumidification control unit is working, receives a self-cleaning command, and the target indoor terminal corresponding to the self-cleaning command is different from the indoor terminal controlled by the reheat dehumidification control unit.

[0010] In some embodiments of the present invention, the intervention control unit is configured to perform the following control based on the difference between the supply air temperature of the indoor terminal controlled by the reheat dehumidification control unit and the real-time indoor temperature corresponding to the indoor terminal controlled by the reheat dehumidification control unit: when the reheat dehumidification control unit is working, receives a self-cleaning command, and the target indoor terminal corresponding to the self-cleaning command is different from the indoor terminal controlled by the reheat dehumidification control unit, and simultaneously satisfies the condition that the difference between the supply air temperature of the indoor terminal controlled by the reheat dehumidification control unit and the corresponding real-time indoor temperature is below a set value, the auxiliary heating element in the indoor terminal controlled by the reheat dehumidification control unit is activated.

[0011] In some embodiments of the present invention, the intervention control unit is further configured to perform the following control based on the difference between the supply air temperature of the indoor terminal controlled by the reheat dehumidification control unit and the real-time indoor temperature corresponding to the indoor terminal controlled by the reheat dehumidification control unit: when the auxiliary heating element is activated and the difference between the supply air temperature of the indoor terminal controlled by the reheat dehumidification control unit and the corresponding real-time indoor temperature is greater than or equal to a set value, the auxiliary heating element in the indoor terminal controlled by the reheat dehumidification control unit is turned off.

[0012] In some embodiments of the present invention, the intervention control unit is configured to shut down the auxiliary heating element in the indoor terminal controlled by the reheat dehumidification control unit after the self-cleaning control unit stops working.

[0013] In some embodiments of the present invention, the auxiliary control element is a regulating expansion valve, which is disposed on the liquid inlet pipe of the indoor heat exchanger connected to the compressor when the reheat dehumidification control is performed and the indoor heat exchanger is in a condensing state. The intervention control unit is further configured to, when the self-cleaning control unit is working, receives a reheat dehumidification command, and the target indoor terminal corresponding to the reheat dehumidification command is different from the indoor terminal controlled by the self-cleaning control unit, keep the self-cleaning control unit waiting, and adjust the regulating expansion valve corresponding to the indoor terminal controlled by the self-cleaning control unit from its maximum opening to a target opening so that the surface of the indoor heat exchanger located downstream of the regulating expansion valve in the indoor terminal controlled by the self-cleaning control unit freezes.

[0014] In some embodiments of the present invention, the intervention control unit is configured to perform the following control based on the coil temperature of the indoor heat exchanger operating in a condensing state when reheat dehumidification control is performed in the indoor terminal controlled by the self-cleaning control unit: periodically correcting the target opening degree; when the coil temperature is above a set judgment temperature, performing valve closing control on the regulating expansion valve based on the actual opening degree of the previous correction cycle; when the coil temperature is below the set judgment temperature, performing valve opening control on the regulating expansion valve based on the actual opening degree of the previous correction cycle.

[0015] In some embodiments of the present invention, the intervention control unit has a plurality of valve-closing temperature thresholds lower than the determination temperature and a valve-closing adjustment amount that decreases as the valve-closing temperature thresholds decrease; when the coil temperature is above the set determination temperature, the valve-closing adjustment amount is selected according to the valve-closing temperature thresholds to perform valve-closing control on the regulating expansion valve; the intervention control unit has a plurality of valve-opening temperature thresholds lower than the determination temperature and an valve-opening adjustment amount that increases as the valve-opening temperature thresholds decrease; when the coil temperature is below the set determination temperature, the valve-opening adjustment amount is selected according to the valve-opening temperature thresholds to perform valve-opening control on the regulating expansion valve.

[0016] In some embodiments of the present invention, the intervention control unit is configured to keep the regulating expansion valve in the indoor terminal controlled by the reheat dehumidification control unit at its maximum opening when the reheat dehumidification control unit is operating, receives a self-cleaning command, and the target indoor terminal corresponding to the self-cleaning command is different from the indoor terminal controlled by the reheat dehumidification control unit.

[0017] In some embodiments of the present invention, the intervention control unit is configured to restore the regulating expansion valve to its maximum opening after the reheat dehumidification control unit stops operating.

[0018] Compared with the prior art, the advantages and positive effects of the present invention are:

[0019] This invention can overcome the contradiction between reheat dehumidification and self-cleaning functions, and avoid linear waiting time-sharing operation that reduces user experience.

[0020] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of one embodiment of the central air conditioning system provided by the present invention;

[0023] Figure 2 For example Figure 1 The diagram shows the functional module structure of the controller in a central air conditioning system.

[0024] Figure 3 For example Figure 1 The diagram shows the refrigerant flow path when one indoor terminal of a central air conditioning system is performing reheat dehumidification operation and the other indoor terminal is shut down.

[0025] Figure 4 A schematic diagram of the refrigerant flow path in an embodiment of the central air conditioning system provided by the present invention;

[0026] Figure 5 A flowchart illustrating an embodiment of the central air conditioning system provided by the present invention;

[0027] Figure 6 A flowchart illustrating an embodiment of the central air conditioning system provided by the present invention;

[0028] Figure 7 A schematic diagram of the refrigerant flow path in an embodiment of the central air conditioning system provided by the present invention;

[0029] Figure 8 A flowchart illustrating an embodiment of the central air conditioning system provided by the present invention;

[0030] Figure 9 A flowchart illustrating an embodiment of the central air conditioning system provided by the present invention;

[0031] Figure 10 A flowchart illustrating one embodiment of the central air conditioning system provided by the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0034] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0036] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0038] Figure 1 This is a structural diagram of the central air conditioning system according to the first embodiment.

[0039] The central air conditioning system 1 includes an outdoor unit 10 and indoor terminals (A, B).

[0040] The outdoor unit 10 is installed in the outdoor environment. The outdoor unit 10 includes a compressor 100, an outdoor heat exchanger 102, an outdoor fan (not shown in the figure), a throttling element 104, and necessary sensors (such as the discharge pressure sensor of the compressor 100). The compressor 100 can adjust its operating frequency through frequency conversion control, thereby compressing the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant.

[0041] The indoor terminals are installed in air-conditioned rooms. Two or more indoor terminals are installed. As shown in the figure, indoor terminal A and indoor terminal B are installed in different air-conditioned rooms. Each indoor terminal is equipped with two indoor heat exchangers (A-1, A-2, B-1, and B-2). For ease of description, the two indoor heat exchangers in the indoor terminal will be distinguished as main heat exchanger and auxiliary heat exchanger in the following text. In this embodiment, the heat exchange capacity of the main heat exchanger (A-1 and B-1) is superior to that of the auxiliary heat exchanger (A-2 and B-2). Each indoor terminal is also equipped with a first expansion valve (A_EVI and B_EVI), a second expansion valve (A_EVI_1 and B_EVI_1), an indoor fan (not shown in the figure), and necessary sensors, such as temperature sensors configured to detect the supply air temperature, and temperature sensors for detecting the coil temperatures of the main heat exchanger and auxiliary heat exchanger.

[0042] The two indoor heat exchangers can operate in either evaporation or condensation mode: when both the main heat exchanger and the auxiliary heat exchanger are operating in evaporation mode, the indoor terminal operates in cooling mode; when both the main heat exchanger and the auxiliary heat exchanger are operating in condensation mode, the indoor terminal operates in heating mode.

[0043] The central air conditioning system also includes a controller 30 that controls the operation of the outdoor unit 10 and the indoor terminals (A, B). The controller 30 consists of an indoor controller located in the indoor terminal and an outdoor controller located in the outdoor unit 10. The indoor and outdoor controllers each include a processor, a memory, and a communication interface, and each receives detection signals from various sensors. The outdoor and indoor controllers are communicatively connected. The indoor controller receives control commands corresponding to different functions from a remote control, wired controller, or control terminal and transmits them to the communicatively connected outdoor controller. The outdoor controller controls the components in the outdoor unit 10, while simultaneously, the indoor controller controls the components in the indoor terminal.

[0044] The controller 30 has a reheat dehumidification control unit 302, a self-cleaning control unit 304, and an intervention control unit 306. Figure 2 This is a functional structure diagram of controller 30.

[0045] The reheat dehumidification control unit 302 is a functional module of the controller 30. The reheat dehumidification control unit 302 is configured to perform the following function: when receiving a reheat dehumidification command, it causes one indoor heat exchanger in one indoor terminal to operate in the evaporation state and the other to operate in the condensation state.

[0046] Figure 3 The refrigerant flow path is shown when indoor terminal A is in reheat dehumidification operation. (Reference) Figure 3 Taking the setup of two indoor terminals (A and B) as an example, this paper introduces the refrigeration cycle loop of the central air conditioning system when the reheat dehumidification control unit performs its function. Figure 1 As shown, the central air conditioning system includes indoor terminal A and indoor terminal B. Indoor terminal A is equipped with a main heat exchanger A-1 and a secondary heat exchanger A-2, and indoor terminal B is equipped with a main heat exchanger B-1 and a secondary heat exchanger B-2. Assuming a user intends to control indoor terminal A to perform reheat dehumidification, a reheat dehumidification command is generated via remote control. The reheat dehumidification control unit is configured to operate the main heat exchanger A-1 in indoor terminal A in evaporation mode and the secondary heat exchanger A-2 in condensation mode upon receiving the reheat dehumidification command.

[0047] like Figure 1 and Figure 3As shown, when the main heat exchanger A-1 in indoor terminal A is operating in the evaporation state and the auxiliary heat exchanger A-2 is operating in the condensation state, on the one hand, the refrigerant circuit between compressor 100, check valve 112, first solenoid valve 118, high and low pressure solenoid valves 110, high and low pressure piping 204, auxiliary heat exchanger A-2, and second expansion valve A_EVI_1 is connected; on the other hand, the refrigerant circuit between compressor 100, check valve 112, four-way valve 114, outdoor heat exchanger 102, throttling element 104, high pressure solenoid valve 106, and high pressure piping 200 is connected; the two piping circuits form a parallel refrigerant circuit. The refrigerant flowing out from auxiliary heat exchanger A-2 and outdoor heat exchanger 102 flows into the main heat exchanger A-1 through the first expansion valve A_EVI, and returns to compressor 100 through low pressure piping 202, low pressure solenoid valve 108, four-way valve 114, and gas-liquid separator 120. Meanwhile, the second solenoid valve 116 between the high and low pressure solenoid valve 110 and the four-way valve 114 remains closed.

[0048] The self-cleaning control unit 304 is another functional module of the controller 300, which is configured to perform the following function: when receiving a self-cleaning command, it causes the two indoor heat exchangers in an indoor terminal to first operate in the evaporation state and then in the condensation state.

[0049] refer to Figure 1 Assuming the user intends to control indoor terminal B to perform a self-cleaning operation, a self-cleaning command is generated via remote control. The self-cleaning control unit is configured to, upon receiving the self-cleaning command, first operate the main heat exchanger B-1 and the auxiliary heat exchanger B-2 in indoor terminal B in an evaporation state, and then in a condensation state. When the main heat exchanger B-1 and the auxiliary heat exchanger B-2 operate in the evaporation state, a large amount of condensate is generated, softening the dirt. Then, the main heat exchanger B-1 and the auxiliary heat exchanger B-2 are rapidly frozen, encapsulating the dirt. Finally, the main heat exchanger B-1 and the auxiliary heat exchanger B-2 are operated in the condensation state, and the de-icing generates a large amount of condensate, flushing away the dirt.

[0050] When the main heat exchanger B-1 in indoor terminal B is operating in the evaporation state, and the auxiliary heat exchanger B-2 is also operating in the evaporation state, on the one hand, the refrigerant circuit between compressor 100, check valve 112, four-way valve 114, outdoor heat exchanger 102, throttling element 104, high-pressure solenoid valve 106, high-pressure piping 200, first expansion valve B_EVI, main heat exchanger B-1, low-pressure piping 202, and low-pressure solenoid valve 108 is connected; on the other hand, the refrigerant circuit between compressor 100, check valve 112, four-way valve 114, outdoor heat exchanger 102, throttling element 104, high-pressure solenoid valve 106, high-pressure piping 200, second expansion valve B_EVI_1, auxiliary heat exchanger B-2, high and low pressure piping 204, high and low pressure solenoid valve 110, and second solenoid valve 116, and the downstream of the two refrigerant four-way valves 114 converge and return to compressor 100 through gas-liquid separator 120. Meanwhile, the first solenoid valve 118 between the one-way valve 112 and the high and low pressure solenoid valves 110 remains closed.

[0051] Since all indoor terminals use the same piping connection structure, when two indoor terminals are simultaneously performing reheat dehumidification and self-cleaning processes to remove ice and dirt, it is impossible for the refrigerant in the high and low pressure piping 204 to exist in both states at the same time. Therefore, a specially designed intervention control unit is configured to perform the following function: when one of the reheat dehumidification control unit and the self-cleaning control unit is in operation, and receives a control command from the other unit, and the target indoor terminal corresponding to the control command is different from the currently operating indoor terminal, intervention control is executed, and an auxiliary control element in the currently operating indoor terminal is activated to perform functional compensation for the former. In this way, during central air conditioning operation, there is no need to wait for one to complete before allowing the other to operate, ensuring that the user experience is not affected.

[0052] As described above, the central air conditioning system performs intervention control and achieves functional compensation through the reheat and dehumidification control unit 302, the self-cleaning control unit 304, and the intervention control unit 306. In some alternative embodiments, such as Figure 4 As shown, the auxiliary control elements are auxiliary heating elements (A-3 and B-3) installed in the indoor terminal.

[0053] In this embodiment, the intervention control unit 306 is specifically configured to perform the following functions: when the reheat dehumidification control unit 302 is working, receives a self-cleaning command, and the target indoor terminal corresponding to the self-cleaning command is different from the indoor terminal controlled by the reheat dehumidification control unit 302, the reheat dehumidification control unit 302 is kept suspended and waits, and the auxiliary heating element in the indoor terminal controlled by the reheat dehumidification control unit 302 is started.

[0054] refer to Figure 4 and Figure 5The controller 300 receives a self-cleaning command from the indoor terminal B to perform self-cleaning. At this time, the indoor terminal B is the target control terminal.

[0055] The controller 300 determines whether the reheat dehumidification control unit 302 is performing the reheat dehumidification function.

[0056] If the reheat dehumidification control unit 302 does not perform the reheat dehumidification function, the self-cleaning control unit 304 controls the indoor terminal B to enter the self-cleaning working state.

[0057] If the reheat dehumidification control unit 302 is performing the reheat dehumidification function, it further determines whether the indoor terminal currently in the reheat dehumidification working state is indoor terminal B.

[0058] If the indoor terminal currently in reheat dehumidification mode is indoor terminal B, then the self-cleaning control unit 304 controls indoor terminal B to switch from reheat dehumidification mode to self-cleaning mode; the main heat exchanger B-1 in indoor terminal B remains in evaporation mode, and the auxiliary heat exchanger B-2 in indoor terminal B switches from evaporation mode to condensation mode.

[0059] If the indoor terminal currently in reheat dehumidification mode is different from indoor terminal B (the target control terminal), for example, indoor terminal A is performing reheat dehumidification, then in response to the user command, the self-cleaning control unit 304 controls indoor terminal B to enter the self-cleaning mode. The main heat exchanger B-1 and auxiliary heat exchanger B-2 in indoor terminal B operate in the evaporation state. Simultaneously, the intervention control unit 306 performs intervention control, keeping the reheat dehumidification control unit 302 suspended and waiting, while simultaneously activating the auxiliary heating element in the indoor terminal controlled by the reheat dehumidification control unit 302, namely, the auxiliary heating element A-3 in indoor terminal A. Since indoor terminals A and B use the same piping connection structure, although the refrigerant in the high and low pressure piping cannot be maintained at a high temperature and high pressure, and the auxiliary heat exchanger A-2 in indoor terminal A cannot provide thermal compensation, the auxiliary heating element can perform the functional compensation of the reheat dehumidification control unit 302, and the reheat dehumidification operation of indoor terminal A will not stop and will be maintained.

[0060] In some embodiments of the present invention, the intervention control unit 306 is configured to perform actions based on the difference between the supply air temperature of the indoor terminal controlled by the reheat dehumidification control unit 302 and the real-time indoor temperature corresponding to the indoor terminal controlled by the reheat dehumidification control unit 302. Figure 6 The controls shown.

[0061] When the reheat dehumidification control unit 302 is operating, it receives a self-cleaning command. If the target indoor terminal corresponding to the self-cleaning command is different from the indoor terminal controlled by the reheat dehumidification control unit 302, and the difference between the supply air temperature and the corresponding real-time temperature of the indoor terminal controlled by the reheat dehumidification control unit 302 is below a set value, the auxiliary heating element in the indoor terminal controlled by the reheat dehumidification control unit 302 is activated. For example, when the difference between the supply air temperature and the real-time temperature is less than 2 degrees Celsius, temperature compensation is achieved through the auxiliary heating element.

[0062] In some embodiments of the present invention, the intervention control unit 306 is configured to perform the control shown in FIG6 based on the difference between the supply air temperature of the indoor terminal controlled by the reheat dehumidification control unit 302 and the real-time indoor temperature corresponding to the indoor terminal controlled by the reheat dehumidification control unit 302.

[0063] When the auxiliary heating element is activated, and the difference between the supply air temperature and the corresponding real-time indoor temperature of the indoor terminal controlled by the reheat dehumidification control unit 302 is greater than or equal to a set value, the auxiliary heating element in the target indoor terminal is turned off. For example, when the difference between the supply air temperature and the real-time temperature is greater than 2 degrees Celsius, the auxiliary heating element is turned off to prevent the supply air temperature from being too high and causing discomfort to the user, thus maintaining a relatively stable indoor temperature while meeting the initial requirements. After the auxiliary heating element is turned off, if the self-cleaning control unit continues to operate, the auxiliary heating element in the indoor terminal controlled by the reheat dehumidification control unit 302 is restarted when the difference between the supply air temperature and the corresponding real-time temperature of the indoor terminal controlled by the reheat dehumidification control unit 302 is less than or equal to a set value. In other cases, the current state of the auxiliary heating element remains unchanged.

[0064] Intervention control unit 306 is configured to shut down the auxiliary heating element in the indoor terminal controlled by reheat dehumidification control unit 302 after self-cleaning control unit 304 stops working. If no reheat dehumidification stop command is received when self-cleaning control unit 304 stops working, intervention control unit 306 controls reheat dehumidification control unit 302 to resume operation, and the main heat exchanger A-1 in indoor terminal A operates in evaporation state, while the auxiliary heat exchanger A-2 in indoor terminal A operates in condensation state.

[0065] In other alternative implementations, such as Figure 7 As shown, the auxiliary control components are regulating expansion valves (C_EVI_2 and D_EVI_2). The regulating expansion valves are installed on the inlet pipe of the indoor heat exchanger connected to the compressor when it is in the condensing state during reheat dehumidification control, that is, in fluid connection with the auxiliary heat exchangers (C_2 and D_2).

[0066] Reference Figure 8As shown, the intervention control unit 306 is specifically configured to perform the following functions: when the self-cleaning control unit 304 is working, receives a reheat dehumidification command, and the target indoor terminal corresponding to the reheat dehumidification command is different from the indoor terminal controlled by the self-cleaning control unit 304, the self-cleaning control unit 304 is kept stopped and waits, and the regulating expansion valve corresponding to the indoor terminal controlled by the self-cleaning control unit 304 is adjusted from the maximum opening to the target opening so that the surface of the indoor heat exchanger located downstream of the regulating expansion valve in the indoor terminal controlled by the self-cleaning control unit 304 freezes.

[0067] refer to Figure 7 and Figure 8 The controller 300 receives a reheat dehumidification command from the indoor terminal D to perform reheat dehumidification. At this time, the indoor terminal D is the target control terminal.

[0068] The controller 300 determines whether the self-cleaning control unit 304 is performing the self-cleaning function.

[0069] If the self-cleaning control unit 304 is not performing the self-cleaning function, the control room terminal D will perform reheat dehumidification.

[0070] If the self-cleaning control unit 304 is performing the self-cleaning function, it further determines whether the indoor terminal currently in the self-cleaning working state is indoor terminal D.

[0071] If the indoor terminal currently in self-cleaning mode is indoor terminal D, then the reheat dehumidification control unit 302 controls indoor terminal D to switch from self-cleaning mode to reheat dehumidification mode; the main heat exchanger D-1 in indoor terminal D remains in evaporation mode, and the auxiliary heat exchanger D-2 in indoor terminal D switches from evaporation mode to condensation mode.

[0072] If the indoor terminal currently in self-cleaning mode is different from indoor terminal D (the target control terminal), for example, indoor terminal C is performing self-cleaning, then in response to user operation, the reheat dehumidification control unit 302 controls indoor terminal D to enter reheat dehumidification mode. The main heat exchanger B-1 in indoor terminal D operates in evaporation mode, and the auxiliary heat exchanger D-2 in indoor terminal D switches from evaporation mode to condensation mode. Simultaneously, the intervention control unit 306 performs intervention control, keeping the self-cleaning control unit 304 suspended and waiting. It also adjusts the regulating expansion valve C_EVR_2 corresponding to indoor terminal C from its maximum opening to the target opening, allowing low-temperature, low-pressure refrigerant to flow into the auxiliary heat exchanger C-2 of indoor terminal C, downstream of the regulating expansion valve C_EVR_2, causing ice to form on the surface of the auxiliary heat exchanger C-2 to compensate for the self-cleaning function. Since indoor terminal C and indoor terminal D use the same piping connection structure, at this time, since indoor terminal D has entered the reheat dehumidification mode, the refrigerant in the high and low pressure piping cannot be maintained at a low temperature and low pressure state. However, adjusting the expansion valve C_EVR_2 can throttle the refrigerant into a low temperature and low pressure liquid state and enter the auxiliary heat exchanger C-2 of indoor terminal C to continue the self-cleaning process and compensate for the self-cleaning process.

[0073] In some embodiments of the present invention, the intervention control unit 306 is configured to perform actions based on the coil temperature of the indoor heat exchanger operating in a condensing state when reheat dehumidification control is performed in the indoor terminal controlled by the self-cleaning control unit 304. Figure 9 The control is shown. For example, the coil temperature of the auxiliary heat exchanger C-2 at indoor terminal C is taken as an example.

[0074] Set the initial opening of the regulating expansion valve C_EVR_2 to the maximum opening;

[0075] The coil temperature of the auxiliary heat exchanger C-2 at terminal C in the sampling room;

[0076] If the coil temperature of the auxiliary heat exchanger C-2 at indoor terminal C is above the judgment temperature, the regulating expansion valve C_EVR_2 is closed based on the actual opening degree of the previous correction cycle.

[0077] If the coil temperature of the auxiliary heat exchanger C-2 at indoor terminal C is below the judgment temperature, the valve opening control of the regulating expansion valve C_EVR_2 is performed based on the actual opening degree of the previous correction cycle.

[0078] The actual opening degree of the first correction cycle is the initial opening degree of the regulating expansion valve C_EVR_2.

[0079] In some embodiments of the present invention, the intervention control unit 306 has a plurality of valve-closing temperature thresholds that are higher than the determination temperature and a plurality of valve-closing adjustment amounts that decrease as the valve-closing temperature thresholds decrease.

[0080] When the coil temperature is above the set judgment temperature, the valve closing adjustment amount is selected according to the valve closing temperature threshold to perform valve closing control on the regulating expansion valve.

[0081] For example, if the temperature is determined to be -10 degrees Celsius, and the coil temperature of the auxiliary heat exchanger C-2 at indoor terminal C is above -10 degrees Celsius, the regulating expansion valve C_EVR_2 is closed based on the actual opening degree of the previous correction cycle. The valve closing temperature threshold can be optionally set to 0 degrees Celsius, and the valve closing adjustment amount can be optionally set to 15pls or 5pls. If the coil temperature of the auxiliary heat exchanger C-2 at indoor terminal C is above -10 degrees Celsius but below 0 degrees Celsius, the valve is closed for 5pls in each correction cycle; if the coil temperature of the auxiliary heat exchanger C-2 at indoor terminal C is above 0 degrees Celsius, the valve is closed for 15pls in each correction cycle.

[0082] In some embodiments of the present invention, the intervention control unit 306 has a plurality of valve opening temperature thresholds lower than the determination temperature and a plurality of valve opening adjustment amounts that increase as the valve opening temperature thresholds decrease.

[0083] When the coil temperature is below the set judgment temperature, the valve opening adjustment amount is selected according to the valve opening temperature threshold to perform valve opening control on the regulating expansion valve.

[0084] For example, if the temperature is determined to be -10 degrees Celsius, and the coil temperature of the auxiliary heat exchanger C-2 at indoor terminal C is below -10 degrees Celsius, the valve opening control of the regulating expansion valve C_EVR_2 is performed based on the actual opening degree of the previous correction cycle. The valve opening temperature threshold can be optionally set to -15 degrees Celsius, and the valve opening adjustment amount can be optionally set to 0pls and 10pls. If the coil temperature of the auxiliary heat exchanger C-2 at indoor terminal C is below -10 degrees Celsius but above -15 degrees Celsius, the valve is opened for 0pls in each correction cycle, i.e., the valve opening degree remains unchanged; if the coil temperature of the auxiliary heat exchanger C-2 at indoor terminal C is above -15 degrees Celsius, the valve is opened for 10pls in each correction cycle.

[0085] In some alternative implementations, such as Figure 7 As shown, the auxiliary control components include both auxiliary heating elements (C-3, D-3) installed in the indoor terminal and regulating expansion valves (C_EVR_2 and D_EVR_2) installed on the liquid inlet pipe of the indoor heat exchanger connected to the compressor when it is in condensation state during reheat dehumidification control.

[0086] like Figure 10As shown, in addition to the embodiments detailed above, in some other embodiments of the present invention, the intervention control unit 306 is further configured to, when the reheat dehumidification control unit 302 is operating, receives a self-cleaning command, and the target indoor terminal corresponding to the self-cleaning command is different from the indoor terminal controlled by the reheat control unit, while keeping the reheat dehumidification control unit 302 stopped operating and waiting, and starting the auxiliary heating element in the indoor terminal controlled by the reheat dehumidification control unit 302, keep the regulating expansion valve in the indoor terminal controlled by the reheat dehumidification control unit 302 at its maximum opening. For example, when the auxiliary heating element C-3 is operating, the regulating expansion valve C_EVR_2 is at its maximum opening.

[0087] Intervention control unit 306 is configured to restore the regulating expansion valve to its maximum opening after the reheat dehumidification control unit 302 stops working; exemplarily, it restores the regulating expansion valve C_EVR_2 to its maximum opening. If no self-cleaning stop command is received when the reheat dehumidification control unit 302 stops working, intervention control unit 306 controls self-cleaning control unit 304 to resume operation, the main heat exchanger A-1 in indoor terminal C operates in evaporation state, the auxiliary heat exchanger A-2 in indoor terminal C operates in evaporation state, and the self-cleaning timer restarts, causing ice to form on the surfaces of the main heat exchanger A-1 and auxiliary heat exchanger A-2 in indoor terminal C.

[0088] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0089] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. Central air conditioning, including: compressor; Outdoor heat exchanger; Throttling element; And at least two indoor terminals, each of which is equipped with two indoor heat exchangers; The two indoor heat exchangers can operate in either evaporation or condensation mode, respectively. Its characteristic is that it further includes: Adjustable expansion valve, which is installed on the liquid inlet line of the compressor connected to the indoor heat exchanger that is in condensation state when performing reheat dehumidification control; The controller has: The reheat dehumidification control unit is configured to operate one indoor heat exchanger in an indoor terminal in an evaporation state and the other in a condensation state when a reheat dehumidification command is received. The self-cleaning control unit is configured to, upon receiving a self-cleaning command, cause two indoor heat exchangers in one indoor terminal to first operate in an evaporation state and then in a condensation state; and the intervention control unit is configured to, while the self-cleaning control unit is performing self-cleaning operation, receive a control command sent by the reheat dehumidification control unit, and when the indoor terminal controlled by the self-cleaning control unit is different from the indoor terminal controlled by the reheat dehumidification control unit, the reheat dehumidification control unit controls the corresponding indoor terminal to enter the reheat dehumidification operation state; keep the self-cleaning control unit suspended and waiting, and adjust the regulating expansion valve corresponding to the indoor terminal controlled by the self-cleaning control unit from the maximum opening to the target opening, so that the surface of the indoor heat exchanger controlled by the self-cleaning control unit freezes.

2. The central air conditioning system according to claim 1, characterized in that: The intervention control unit is configured to perform the following control based on the coil temperature of the indoor heat exchanger operating in a condensing state when reheat dehumidification control is performed in the indoor terminal controlled by the self-cleaning control unit: The target opening degree is periodically adjusted; When the coil temperature is above the set judgment temperature, the regulating expansion valve is closed based on the actual opening degree of the previous correction cycle. When the coil temperature is below the set judgment temperature, the regulating expansion valve is opened based on the actual opening degree of the previous correction cycle.

3. The central air conditioning system according to claim 2, characterized in that: The intervention control unit has several valve-closing temperature thresholds lower than the determination temperature and a valve-closing adjustment amount that decreases as the valve-closing temperature thresholds decrease. When the coil temperature is above the set judgment temperature, the valve closing adjustment amount is selected according to the valve closing temperature threshold to perform valve closing control on the regulating expansion valve. The intervention control unit has several valve opening temperature thresholds lower than the determination temperature and a valve opening adjustment amount that increases as the valve opening temperature threshold decreases. When the coil temperature is below the set judgment temperature, the valve opening adjustment amount is selected according to the valve opening temperature threshold to perform valve opening control on the regulating expansion valve.

4. The central air conditioning system according to claim 1, characterized in that... : The intervention control unit is configured to maintain the regulating expansion valve in the indoor terminal controlled by the reheat dehumidification control unit at its maximum opening when the reheat dehumidification control unit is working, receives a self-cleaning command, and the target indoor terminal corresponding to the self-cleaning command is different from the indoor terminal controlled by the reheat dehumidification control unit.

5. The central air conditioning system according to claim 1, characterized in that: The intervention control unit is configured to restore the regulating expansion valve to its maximum opening after the reheat dehumidification control unit stops working.

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