Defrosting control method and device of multi-split air conditioning system and storage medium thereof

Abstract

The embodiment of the invention discloses a defrosting control method and device for a multi-split air conditioning system and a storage medium, and the method comprises the steps that when at least one outdoor unit meets the defrosting condition, it is determined that the outdoor unit needing to be defrosted is a first outdoor unit, and other outdoor units are second outdoor units; one first outdoor unit is selected as a target outdoor unit to enter a defrosting mode; and when the energy demand sum value of the multiple indoor devices is smaller than or equal to the energy consumption threshold value, the output power of the second outdoor unit is increased, so that the sum of the output power of the outdoor units is equal to the energy demand sum value of the indoor devices. According to the energy demand sum value of the indoor equipment and the maximum output power sum value of the outdoor units, the target outdoor unit is controlled to enter the defrosting mode, the output power of the second outdoor unit and the energy demand sum value of the indoor equipment are adjusted, and the situation that the indoor equipment is unstable in heating due to the fact that the outdoor units cannot meet the energy demand value of the indoor equipment in the defrosting process is avoided; and the comfort of the user is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of defrosting, and particularly to a defrosting control method, device and storage medium for a multi-connected air conditioner system. Background Art

[0002] When an air conditioner system heats in a cold condition, there is a problem of frosting on the evaporator of the outdoor unit. To ensure the heating effect, the outdoor unit needs to perform a defrosting operation. At this time, due to the working principle of the defrosting operation, the heating capacity of the outdoor unit decreases during the defrosting process, resulting in cold air being generated indoors, which will make the indoor environment very cold and greatly affect the user experience during heating. Especially in an air conditioner system with multiple outdoor units, the defrosting operations of multiple outdoor units have a more obvious impact on the heating effect of the air conditioner system. Summary of the Invention

[0003] An object of the present invention is to at least solve one of the technical problems existing in the prior art, and provide a defrosting control method, device and storage medium for a multi-connected air conditioner system, which can effectively control the outdoor unit to perform a defrosting operation and avoid the defrosting operations of multiple outdoor units from affecting the heating effect of indoor equipment.

[0004] In a first aspect, an embodiment of the present invention provides a defrosting control method for a multi-connected air conditioner system. The multi-connected air conditioner system includes a plurality of indoor devices and a plurality of cascaded outdoor units. The outdoor unit includes a main unit and a slave unit. The defrosting control method is applied to the main unit and includes:

[0005] When at least one of the outdoor units meets the defrosting condition, determine the outdoor unit that needs to be defrosted as the first outdoor unit, and the other outdoor units as the second outdoor units. Select one of the first outdoor units as the target outdoor unit to enter the defrosting mode;

[0006] When the total energy demand value of the plurality of indoor devices is less than or equal to the energy consumption threshold, increase the output power of the second outdoor units so that the total output power of the outdoor units is equal to the total energy demand value of the indoor devices, where the energy consumption threshold is determined by the total maximum power of all the second outdoor units or the total maximum power of all the outdoor units except the target outdoor unit;

[0007] When the total energy demand value of the plurality of indoor devices is greater than the energy consumption threshold, adjust the operating parameters of the indoor devices to reduce the energy demand value of the indoor devices so that the total output power of the outdoor units is equal to the total energy demand value of the indoor devices.

[0008] The defrost control method of the multi-connected air conditioner system provided by the embodiment of the present invention has at least the following beneficial effects: according to the total energy demand value of the indoor devices and the total maximum output power of the outdoor units, control the target outdoor unit to enter the defrost mode, and adjust the output power of the second outdoor unit and the total energy demand value of the indoor devices, so as to avoid the situation that the outdoor unit cannot meet the energy demand value of the indoor devices during the defrost process, resulting in unstable heating of the indoor devices and ensuring the comfort of users.

[0009] In the above defrost control method of the multi-connected air conditioner system, the defrost control method further includes:

[0010] When the local unit meets the defrost condition, or when receiving the defrost request signal sent by the target outdoor unit, count the total energy demand value of the multiple indoor devices, where the defrost request signal indicates that the outdoor unit meets the defrost condition.

[0011] In the above defrost control method of the multi-connected air conditioner system, the outdoor unit includes a hydraulic module, a refrigerant circulation module, and a plate heat exchanger. The water outlet and water inlet of the plate heat exchanger are connected to the hydraulic module, and the refrigerant outlet and refrigerant inlet of the plate heat exchanger are connected to the refrigerant circulation module;

[0012] When at least one of the outdoor units meets the defrost condition, determining the outdoor unit that needs to defrost as the first outdoor unit and the other outdoor units as the second outdoor units includes:

[0013] When the refrigerant heat exchanger temperature of the refrigerant circulation module of the outdoor unit is less than a preset first temperature threshold, or the heating duration of the refrigerant circulation module is greater than a preset time threshold, determine the outdoor unit as the first outdoor unit;

[0014] When the refrigerant heat exchanger temperature of the refrigerant circulation module of the outdoor unit is greater than the first temperature threshold and the heating duration of the refrigerant circulation module is less than the time threshold, determine the outdoor unit as the second outdoor unit.

[0015] In the above defrost control method of the multi-connected air conditioner system, selecting one of the first outdoor units as the target outdoor unit to enter the defrost mode includes:

[0016] Determine the target outdoor unit according to the refrigerant heat exchanger temperature and the heating duration of the refrigerant circulation module;

[0017] Close the pump body of the hydraulic module of the target outdoor unit, and control the refrigerant circulation module of the target outdoor unit to enter the defrost mode;

[0018] When the water outlet temperature of the plate heat exchanger is lower than a preset second temperature threshold, start the pump body.

[0019] In the defrost control method of the above multi-connected air conditioner system, after controlling the target outdoor unit to enter the defrost mode, the defrost control method further includes:

[0020] When the temperature of the refrigerant heat exchanger of the refrigerant circulation module is greater than a preset third temperature threshold, control the refrigerant circulation module of the target outdoor unit to enter the heating mode, where the third temperature threshold is greater than the first temperature threshold.

[0021] In the defrost control method of the above multi-connected air conditioner system, the energy demand threshold is determined by the following method:

[0022] Determine the energy consumption threshold according to the maximum output power of each outdoor unit, according to the total maximum power of all the second outdoor units, or determine the energy consumption threshold according to the total maximum power of all outdoor units except the target outdoor unit.

[0023] In the defrost control method of the above multi-connected air conditioner system, when the total energy demand value of multiple indoor devices is greater than the energy consumption threshold, adjust the operating parameters of the indoor devices to reduce the energy demand value of the indoor devices, so that the total output power of the outdoor units is equal to the total energy demand value of the indoor devices, including:

[0024] Determine the increased value of the output power of the second outdoor unit according to the total energy demand value of the indoor devices and the total power output value of the outdoor units;

[0025] Adjust the output power of the second outdoor unit according to the increased value.

[0026] In the defrost control method of the above multi-connected air conditioner system, the increased values of the output powers of multiple second outdoor units are equal.

[0027] In the defrost control method of the above multi-connected air conditioner system, when the total energy demand value of the indoor devices is greater than the energy consumption threshold, adjust the total energy demand value of the indoor devices and increase the output power of the second outdoor units, so that the total output power of the second outdoor units is equal to the total energy demand value of the indoor devices, further includes:

[0028] When the total energy demand value of the indoor devices is greater than the energy consumption threshold, and the second outdoor units are all in full-load operation, determine the reduced value of the total energy demand value of the indoor devices according to the difference between the total energy demand value of the indoor devices and the energy consumption threshold;

[0029] Adjust the operating parameters of the indoor devices according to the reduced value, so that the total output power of the second outdoor units is equal to the total sum of the total energy demand values of the indoor devices.

[0030] In the defrosting control method of the above multi-connected air conditioner system, the indoor device is a air supply device, and the air supply device includes a fan;

[0031] Adjusting the operating parameters of the indoor device according to the reduction value includes:

[0032] Reducing the fan speed of the indoor device according to the reduction value.

[0033] In a second aspect, an embodiment of the present invention provides a defrosting control device for a multi-connected air conditioner system, which is characterized by including at least one control processor and a memory communicatively connected to the at least one control processor; the memory stores instructions executable by the at least one control processor, and the instructions are executed by the at least one control processor to enable the at least one control processor to execute the control method as described above.

[0034] The defrosting control device for a multi-connected air conditioner system provided by an embodiment of the present invention has at least the following beneficial effects: According to the total energy demand value of the indoor device and the total maximum output power of the outdoor units, controlling the target outdoor unit to enter the defrosting mode, and adjusting the output power of the second outdoor unit and the total energy demand value of the indoor device, avoiding the situation that the outdoor unit cannot meet the energy demand value of the indoor device during defrosting, resulting in unstable heating of the indoor device, and ensuring the comfort of users.

[0035] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium, which is characterized in that the computer-readable storage medium stores computer-executable instructions for causing a computer to execute the control method as described above.

[0036] The computer-readable storage medium provided by an embodiment of the present invention has at least the following beneficial effects: According to the total energy demand value of the indoor device and the total maximum output power of the outdoor units, controlling the target outdoor unit to enter the defrosting mode, and adjusting the output power of the second outdoor unit and the total energy demand value of the indoor device, avoiding the situation that the outdoor unit cannot meet the energy demand value of the indoor device during defrosting, resulting in unstable heating of the indoor device, and ensuring the comfort of users.

[0037] Other features and advantages of the present invention will be described in the following description, and some of them will become obvious from the description, or be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structures specifically pointed out in the description, the claims, and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings are used to provide a further understanding of the technical solutions of the present application, and constitute a part of the description. They are used together with the embodiments of the present application to explain the technical solutions of the present application, and do not constitute a limitation to the technical solutions of the present application.

[0039] Figure 1 It is a flowchart of a defrost control method for a multi-connected air conditioner system provided by an embodiment of the present application;

[0040] Figure 2 is Figure 1 a flowchart of step S1000 in

[0041] Figure 3 is Figure 1 a flowchart of step S1000 provided by another embodiment of the present application in

[0042] Figure 4 is Figure 1 a flowchart of step S2000 in

[0043] Figure 5 is Figure 1 a flowchart of step S3000 in

[0044] Figure 6 It is a schematic diagram of a defrost control device for a multi-connected air conditioner system provided by an embodiment of the present application. Detailed implementation manners

[0045] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present application and should not be construed as limiting the present application.

[0046] In the description of the present application, it should be understood that for the orientation descriptions, such as upper, lower, front, rear, left, right, etc., the orientation or positional relationships indicated are those shown in the accompanying drawings. They are only for facilitating the description of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application.

[0047] In the description of the present application, the meaning of "a number of" is one or more, the meaning of "a plurality of" is more than two, "greater than", "less than", "exceeding", etc. are understood as not including the recited number, and "above", "below", "within", etc. are understood as including the recited number. If there is a description of "first", "second", it is only for the purpose of distinguishing technical features and should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0048] In the description of the present application, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present application in combination with the specific content of the technical solution.

[0049] The embodiments of the present application provide a defrost control method, device and storage medium for a multi-connected air conditioner system, which can control the target outdoor unit to enter the defrost mode according to the total energy demand value of indoor devices and the total maximum output power of outdoor units, and adjust the output power of the second outdoor unit and the total energy demand value of indoor devices, so as to avoid the situation that the outdoor unit cannot meet the energy demand value of indoor devices during defrosting, resulting in unstable heating of indoor devices and ensuring the comfort of users.

[0050] The multi-connected air conditioner system involved in the embodiments of the present application includes multiple indoor devices and multiple cascaded outdoor units, and the outdoor units include a host and a slave. Specifically, the multi-connected air conditioner system belongs to a water-air-water system, which is a combined system of a central air conditioner that exchanges heat through water in indoor devices and an air-source water floor heating. The working principle of the water-air-water system is that the outdoor unit first exchanges heat between water and refrigerant, cools the water and then sends it to the indoor device through a water pipe for refrigeration, or heats the water and then transmits it to the indoor device through a water pipe for heating, which belongs to secondary heat exchange. In the water-air-water system, during secondary heat exchange for refrigeration, the outlet air temperature of the indoor device during refrigeration is between 15°C and 20°C, and the outlet air is gentle and the body feeling is comfortable. In addition, the water system does not limit the connection ratio of indoor and outdoor units. In application scenarios with a relatively low simultaneous operation rate, the matching ratio of indoor and outdoor units is relatively low, resulting in a relatively low cost of indoor devices, thus creating the high cost-performance characteristic of the water-air-water system and being widely used in various refrigeration and heating scenarios.

[0051] Currently, in order to meet the energy consumption requirements of indoor devices, the water-air-water system usually needs to be equipped with multiple outdoor units to cool or heat the water in the system. Among them, during the heating process, since the evaporation temperature of the outdoor unit heat exchanger is lower than zero degree, the outdoor air flowing through the condenser will condense on the fins and frost will form. The frost will affect the heat exchange area of the condenser and the air flow rate, thereby affecting the heating effect of the outdoor unit. Therefore, in order to ensure the heating effect of the water-air-water system, defrosting operation must be carried out. Since the heating capacity of the outdoor unit decreases during defrosting, the temperature of the water entering the indoor device drops significantly, resulting in cold air in the room, which will cause the indoor temperature to drop suddenly and affect the user experience during heating. Especially in an air conditioner system with multiple outdoor units, when multiple outdoor units need to carry out defrosting operations, the impact on the heating effect of the air conditioner system is more obvious. Therefore, a defrost control method is needed that can control the target outdoor unit to enter the defrost mode according to the total energy demand value of indoor devices and the total maximum output power of outdoor units, so as to avoid the situation that the outdoor unit cannot meet the energy demand value of indoor devices during defrosting, resulting in unstable heating of indoor devices.

[0052] The following further elaborates on the embodiments of the present application in conjunction with the accompanying drawings.

[0053] Please refer to Figure 1, Figure 1 shows a flowchart of a defrost control method for a multi-connected air conditioner system provided by an embodiment of the first aspect of the present application. As Figure 1 shown, the defrost control method for the multi-connected air conditioner system includes the following steps:

[0054] Step S1000: When at least one outdoor unit meets the defrost condition, determine the outdoor unit that needs to defrost as the first outdoor unit and other outdoor units as the second outdoor units, and select one of the first outdoor units as the target outdoor unit to enter the defrost mode.

[0055] It can be understood that in a multi-connected air conditioner system, the host, as the control center of the outdoor units, realizes functions such as refrigeration, heating of the outdoor units, and control of the power output of the outdoor units by connecting multiple slave units. The host and the slave units are connected by communication cables, enabling different outdoor units to independently control the power output, improving the comfort and energy-saving effect of the multi-connected air conditioner system.

[0056] It can be understood that during the heating process of the multi-connected air conditioner system, the outdoor unit needs to heat the water transmitted to the indoor equipment. Since the air-conditioning heat exchange of the sky-water and ground-water system no longer directly contacts the refrigerant with the air, but through secondary heat exchange inside the outdoor unit, and the indoor medium is changed to water, the outlet air temperature can be controlled by adjusting the water temperature, which has an absolute advantage in wind feeling and humidity, and improves many problems in the experience of traditional air conditioners. In addition, the operation mode of the air-conditioning floor heating is also very simple. The floor heating itself requires water, and the air conditioner also requires water. Therefore, the sky-water and ground-water air conditioner and the floor heating actually use the same method, and the water supply comes from the outdoor unit. The air conditioner and the floor heating can be turned on at the same time, and only through simple water flow control, a full-range heating effect indoors can be achieved.

[0057] It can be understood that when several outdoor units in the multi-connected air conditioner system stop heating during the defrost operation, the temperature of the water transmitted to the indoor equipment will drop significantly, affecting the heating effect of the indoor equipment. Therefore, before selecting the outdoor unit to enter the defrost mode, it is necessary to determine the number of outdoor units that need to defrost and select one of them for defrosting to achieve the goal of stable control of the energy consumption of the indoor equipment and avoid the sudden drop in room temperature.

[0058] Please refer to Figure 2 , Figure 2 shows a schematic diagram of a specific implementation process of the above step S1000. As Figure 2 shown, step S1000 at least includes the following steps:

[0059] Step S1100: When this unit meets the defrost condition, or when receiving a defrost request signal sent by the target outdoor unit, count the total energy demand value of multiple indoor devices, where the defrost request signal indicates that the outdoor unit meets the defrost condition.

[0060] It is understandable that when the host meets the defrosting condition, in order to stably control the target of indoor equipment energy consumption, it is necessary to count the total energy demand value of multiple indoor equipment, so that the host can adjust the output energy consumption of multiple indoor equipment according to the operating conditions of multiple indoor equipment, avoiding sudden temperature drops in the room due to uneven energy consumption distribution and affecting the user experience. It is prior art for the host to obtain the energy demand values of multiple indoor equipment through communication with the indoor equipment and count their total value, which will not be elaborated here.

[0061] It is understandable that when the slave meets the defrosting condition, it is necessary to send a defrost request signal indicating that the outdoor unit meets the defrosting condition to the host. After receiving the defrost request signal, the host also needs to count the total energy demand value of multiple indoor equipment, so that the host can adjust the output energy consumption of multiple indoor equipment according to the operating conditions of multiple indoor equipment.

[0062] Step S1200: When the refrigerant heat exchanger temperature of the refrigerant circulation module of the outdoor unit is less than a preset first temperature threshold, or the heating duration of the refrigerant circulation module is greater than a preset time threshold, determine that the outdoor unit is the first outdoor unit.

[0063] It is understandable that the condition for the outdoor unit to need defrosting is usually that the temperature of the outdoor coil is lower than the defrosting temperature, and in a multi-connected air conditioner system, it is that the refrigerant heat exchanger temperature of the refrigerant circulation module of the outdoor unit is less than a preset first temperature threshold; specifically, since the surface temperature of the evaporator will reach below the first temperature threshold, such as below zero degrees Celsius, during the winter heating operation of a heat pump type air conditioner, the surface of the refrigerant heat exchanger may frost, and the thick frost layer will cause hindered air flow and affect the heating capacity of the air conditioner; secondly, another condition for defrosting is that the heating duration is greater than the time threshold, and in a multi-connected air conditioner system, it is that the heating duration of the refrigerant circulation module is greater than a preset time threshold. Specifically, during the long-term heating process of the outdoor unit, the surface of the refrigerant heat exchanger will also frost, affecting the heating capacity of the outdoor unit.

[0064] It can be understood that there are generally two types of existing defrosting circuits. One is defrosting during shutdown, where the refrigerant heat exchanger of the refrigerant circulation module stops working to let the frost melt by itself. This method is not feasible at lower temperatures and the frost melting time is relatively long, so air conditioners generally do not use this method. The other is hot gas defrosting, that is, through the reversing valve of the refrigerant circulation module, the evaporator of the outdoor unit becomes a condenser, and the refrigerant heat exchanger is heated up by changing the refrigerant flow direction to achieve the defrosting effect. Specifically, the defrosting controller of the refrigerant circulation module is also an electric switch that uses the temperature control contact to act, and is a special temperature controller for removing the frost layer on the refrigerant heat exchanger of the outdoor unit during heat pump heating. Its defrosting method is generally reverse cycle hot gas defrosting, that is, through the on-off of the contacts of the defrosting controller switch, the electromagnetic reversing valve is reversed to achieve the defrosting effect. Therefore, after the outdoor unit enters the defrosting mode, it will stop outputting power to the indoor equipment, and the temperature of the hot water flowing to the indoor equipment will decrease. Therefore, before the outdoor unit enters the defrosting mode, it is necessary to count the outdoor units that meet the defrosting conditions, that is, determine the outdoor units that meet the defrosting conditions as the first outdoor units, so as to facilitate the host to control the outdoor units that meet the conditions to enter the defrosting mode.

[0065] It can be understood that the process of the host communicating with each outdoor unit, obtaining the temperature of the refrigerant heat exchanger through the temperature acquisition module, and obtaining the heating duration of the refrigerant circulation module through the timing module belongs to the prior art and will not be elaborated here.

[0066] Step S1300: When the temperature of the refrigerant heat exchanger of the refrigerant circulation module of the outdoor unit is greater than the first temperature threshold and the heating duration of the refrigerant circulation module is less than the time threshold, determine the outdoor unit as the second outdoor unit.

[0067] It can be understood that in order to facilitate the reasonable adjustment of the output power of the outdoor units that do not require defrosting operations, before the outdoor unit enters the defrosting mode, it is necessary to count the number of outdoor units that do not meet the defrosting conditions, that is, determine the outdoor units that do not meet the defrosting conditions as the second outdoor units. Contrary to the above step S1200, the outdoor unit must meet the following conditions at the same time to meet the requirement of not requiring defrosting operations, that is, the temperature of the refrigerant heat exchanger of the refrigerant circulation module of the outdoor unit is greater than the first temperature threshold and the heating duration of the refrigerant circulation module is less than the time threshold. At this time, since the surface temperature of the evaporator is greater than the first temperature threshold, for example, above zero degrees, the probability of frosting on the surface of the refrigerant heat exchanger will decrease; at the same time, since the heating duration of the refrigerant circulation module is less than the time threshold, the frost layer on the surface of the refrigerant heat exchanger does not accumulate much, and the heating capacity of the outdoor unit is not affected much.

[0068] It can be understood that by confirming the second outdoor unit, the host can quickly and accurately count the outdoor units that do not require defrosting operations, and the host can accurately grasp the current operating conditions of the outdoor units, so as to adjust the output power of the outdoor units, and avoid the situation of too high output power or uneven output power distribution of the outdoor units, which affects the operating stability of the multi-connected air-conditioning system.

[0069] Please refer to Figure 3 , Figure 3 which shows another schematic diagram of the specific implementation process of the above step S1000. As Figure 3 shown, step S1000 at least further includes the following steps:

[0070] Step S1400: Determine the target outdoor unit according to the temperature of the refrigerant heat exchanger and the heating duration of the refrigerant circulation module.

[0071] It can be understood that after determining the first outdoor unit that meets the defrosting conditions, in order to ensure the operating stability of the multi-connected air-conditioning system and avoid multiple outdoor units defrosting simultaneously, resulting in insufficient output power of the indoor equipment and affecting the heating effect of the multi-connected air-conditioning system, it is necessary to select a target outdoor unit from the first outdoor units, and the host controls the target outdoor unit to perform the defrosting operation.

[0072] It can be understood that in the case of multiple first outdoor units, that is, multiple outdoor units simultaneously meet the defrosting conditions. In order to preferentially select the first outdoor unit with a lower temperature of the refrigerant heat exchanger and a longer heating time of the refrigerant circulation module as the target outdoor unit, so that the host can control the target outdoor unit to perform the defrosting operation and avoid too thick frost layer affecting the normal operation of the outdoor unit. Specifically, the host can sort the first outdoor units by counting the temperature of the refrigerant heat exchanger and the heating duration of the refrigerant circulation module of the first outdoor units, and select a target outdoor unit according to the sorting of the temperature of the refrigerant heat exchanger and the heating duration of the refrigerant circulation module of the first outdoor units. Specifically, the first outdoor unit with the lowest temperature of the refrigerant heat exchanger can be directly selected as the target outdoor unit. When there are first outdoor units with the same temperature of the refrigerant heat exchanger, by comparing the heating duration of the refrigerant circulation module, the one with the longest heating duration of the refrigerant circulation module is selected as the target outdoor unit.

[0073] Step S1500: Close the pump body of the hydraulic module of the target outdoor unit, and control the refrigerant circulation module of the target outdoor unit to enter the defrosting mode.

[0074] It can be understood that the outdoor unit includes a hydraulic module, a refrigerant circulation module, and a plate heat exchanger. The water outlet and water inlet of the plate heat exchanger are connected to the hydraulic module, and the refrigerant outlet and refrigerant inlet of the plate heat exchanger are connected to the refrigerant circulation module. The hydraulic module and the refrigerant circulation module perform heat exchange through the plate heat exchanger. That is, the refrigerant circulation module transmits the high-temperature and high-pressure refrigerant through the refrigerant inlet into the plate heat exchanger, and the hydraulic module transmits the relatively low-temperature water through the water inlet into the plate heat exchanger. The high-temperature and high-pressure refrigerant heats the water in the hydraulic module, and high-temperature water is output from the water outlet of the plate heat exchanger for use by indoor equipment.

[0075] It can be understood that the plate heat exchanger is a highly efficient heat exchanger formed by stacking a series of metal sheets with a certain corrugated shape. Thin rectangular channels are formed between various plate sheets, and heat exchange is carried out through the plate sheets. The plate heat exchanger is an ideal device for heat exchange between liquid and liquid, and between liquid and gas. The plate heat exchanger has the characteristics of high heat transfer efficiency, small heat loss, compact and lightweight structure, small floor area, wide application, long service life, etc. Under the same pressure loss condition, the heat transfer coefficient of the plate heat exchanger is 3-5 times higher than that of the tubular heat exchanger, the floor area is one-third of that of the tubular heat exchanger, and the heat recovery rate can be as high as more than 90%. Therefore, the hydraulic module and the refrigerant circulation module perform heat exchange through the plate heat exchanger, which can effectively improve the efficiency of the outdoor unit.

[0076] It can be understood that after the refrigerant circulation module of the target outdoor unit enters the defrosting mode, through the action of the four-way reversing valve, the refrigerant circulation module is switched from the heating mode to the cooling mode. The high-temperature and high-pressure gas discharged by the compressor of the refrigerant circulation module enters the finned coil of the refrigerant heat exchanger, raising the surface temperature thereof and melting the frost layer. After defrosting, the heat transfer coefficient of the refrigerant heat exchanger increases, the air flow resistance decreases, and its heat exchange efficiency improves. Among them, switching the working mode of the refrigerant circulation module through the reversing valve belongs to the prior art and will not be elaborated here.

[0077] It can be understood that since the refrigerant circulation module inputs low-temperature refrigerant into the plate heat exchanger after switching to the cooling mode, in order to prevent the outdoor unit from outputting cold water to the indoor equipment, it is necessary to turn off the pump body of the hydraulic module of the target outdoor unit so that the water inside the hydraulic module stops circulating, effectively reducing the heat exchange between the target outdoor unit and the indoor equipment, avoiding the impact on the multi-split system after the target outdoor unit enters the defrosting mode, and reducing the energy consumption of the multi-split system.

[0078] Step S1600: When the temperature of the water outlet of the plate heat exchanger is lower than a preset second temperature threshold, start the pump body.

[0079] It can be understood that, as can be seen from the above step S1500, after the refrigerant circulation module switches to the cooling mode, it inputs low-temperature refrigerant into the plate heat exchanger. The low-temperature refrigerant exchanges heat with the water in the hydraulic module in the plate heat exchanger, resulting in a continuous decrease in the outlet temperature of the plate heat exchanger. An excessively low temperature will cause the water in the plate heat exchanger to freeze, affecting the normal water circulation inside the hydraulic module and causing the outdoor unit to malfunction. Therefore, when the outlet temperature of the plate heat exchanger is lower than the preset second temperature threshold, for example, when the outlet temperature of the plate heat exchanger is lower than 2°C, approaching the freezing point of water, the pump body of the hydraulic module is started to make the water inside the hydraulic module flow and take away the water with a lower temperature inside the plate heat exchanger, preventing the water inside the plate heat exchanger from freezing due to the excessively low temperature.

[0080] Step S1700: When the temperature of the refrigerant heat exchanger of the refrigerant circulation module is greater than the preset third temperature threshold, control the refrigerant circulation module of the target outdoor unit to enter the heating mode, where the third temperature threshold is greater than the first temperature threshold.

[0081] It can be understood that when the target outdoor unit performs the defrosting operation for a certain period of time, the temperature of the refrigerant heat exchanger of the refrigerant circulation module rises to reach the third temperature threshold. For example, when the temperature of the refrigerant heat exchanger is greater than 4°C, the defrosting of the refrigerant heat exchanger of the refrigerant circulation module is completed, and the host controls the refrigerant circulation module to exit the defrosting mode and enter the heating mode, so that the refrigerant circulation module continues to heat the water inside the plate heat exchanger. In practical applications, it is also possible to determine whether the target outdoor unit exits the defrosting mode according to the defrosting time of the refrigerant circulation module. It can be understood that controlling the refrigerant circulation module of the target outdoor unit to enter the heating mode according to the magnitude relationship between the temperature of the refrigerant heat exchanger and the third temperature threshold belongs to the prior art and will not be elaborated here.

[0082] Step S2000: When the total energy demand value of multiple indoor devices is less than or equal to the energy consumption threshold, increase the output power of the second outdoor unit so that the total output power of the outdoor units is equal to the total energy demand value of the indoor devices, where the energy consumption threshold is determined by the total maximum power of all second outdoor units or the total maximum power of all outdoor units except the target outdoor unit.

[0083] It can be understood that when the target outdoor unit enters the defrosting mode, since the target outdoor unit stops outputting hot water to the indoor devices, the input energy consumption of the indoor devices is insufficient to meet the energy demand value of the indoor devices. In order to ensure that the indoor devices can heat according to the demand, it is necessary to increase the output power of the second outdoor unit so that the total output power of the outdoor units is equal to the total energy demand value of the indoor devices.

[0084] It can be understood that the indoor devices include indoor temperature control devices such as fan coil units, fresh air units, and radiant panels. When the heat of the hot water input to the indoor devices decreases, in order to avoid excessive changes in the indoor temperature, it is necessary to increase the output power of the second outdoor unit so that the total output power of the outdoor units can meet the total energy demand value of the indoor devices to maintain the heating effect of the indoor devices.

[0085] Please refer to Figure 4 , Figure 4 which shows a schematic diagram of a specific implementation process of the above step S2000. As Figure 4 shown, step S2000 at least includes the following steps:

[0086] Step S2100: Determine the energy consumption threshold according to the maximum output power of each outdoor unit, according to the total maximum power of all second outdoor units, or according to the total maximum power of all outdoor units except the target outdoor unit.

[0087] It can be understood that the magnitude of the maximum output power of the outdoor unit is determined according to the cooling or heating capacity of the outdoor unit, which is generally described in units such as BTU / HR or KW and is usually used to reflect the air-conditioning load. For example, the maximum power of an outdoor air conditioner is 1.5KW, which is approximately 5000BTU / HR. The maximum output power of each outdoor unit is the value set at the factory of the outdoor unit. Therefore, the host can obtain the maximum output power of each outdoor unit through communication with the outdoor unit. Then, by calculating the total maximum power of all second outdoor units or the total maximum power of all outdoor units except the target outdoor unit, the energy consumption threshold is determined. In the embodiments of the present application, since only the target outdoor unit in the first outdoor unit is in the defrosting state and the other first outdoor units are still in the normal working state, in order to reduce the energy consumption of the outdoor unit, the energy consumption threshold is set to the total maximum power of all outdoor units except the target outdoor unit to avoid the situation of excessive energy consumption of the second outdoor unit.

[0088] Step S2200: Determine the increased value of the output power of the second outdoor unit according to the total energy demand value of the indoor devices and the total power output value of the outdoor units.

[0089] It can be understood that when the total energy demand value of multiple indoor devices is less than or equal to the energy consumption threshold, that is, the output power of the outdoor unit can meet the total energy demand value of the indoor devices by increasing the output power of the second outdoor unit. Therefore, by calculating the difference between the total energy demand value of the indoor devices and the total power output value of the outdoor units, the increased value of the total output power of the second outdoor unit can be obtained. By specifically allocating and controlling each second outdoor unit, the increased value of the output power of the second outdoor unit can be obtained.

[0090] Step S2300: Adjust the output power of the second outdoor unit according to the increased value.

[0091] It can be understood that after obtaining the increased value of the output power of the second outdoor units in the above steps, the host outputs an instruction to increase the output power to each second outdoor unit, so that each second outdoor unit increases the output power value corresponding to the increased value, and further makes the total output power of the outdoor units equal to the total energy demand value of the indoor devices. In practical applications, the increased value of the output power of the second outdoor units can be evenly distributed according to the actual operating conditions of each second outdoor unit to ensure the operating stability of the multi-connected air conditioner system. It can be understood that the host adjusts the output power of the second outdoor unit by sending an instruction to increase the output power, which belongs to the prior art and will not be elaborated here.

[0092] Step S2400: The increased values of the output powers of multiple second outdoor units are equal.

[0093] It can be understood that the increased value of the output power of the second outdoor unit obtained in the above step S2200 can be dynamically distributed according to the specific operating conditions of the second outdoor unit. In the embodiment of the present application, the specifications of all outdoor units are the same and their maximum output powers are the same. During the operation of the multi-connected air conditioner system, except for the target outdoor unit in the defrosting state, the remaining outdoor units are all in the load balancing working state. Therefore, in order to ensure that the outdoor units are still in the load balancing state after adjusting the output power of the second outdoor unit, the increased values of the output powers of the second outdoor units are equal. This adjustment method of the output power of the second outdoor unit also enables the output power of the outdoor unit to increase evenly and stably, improving the service life of the outdoor unit and the operating stability of the multi-connected air conditioner system.

[0094] Step S3000: When the total energy demand value of multiple indoor devices is greater than the energy consumption threshold, adjust the operating parameters of the indoor devices to reduce the energy demand value of the indoor devices, so that the total output power of the outdoor units is equal to the total energy demand value of the indoor devices.

[0095] It can be understood that when the target outdoor unit enters the defrosting mode, since the target outdoor unit stops outputting hot water to the indoor devices, the input energy consumption of the indoor devices is insufficient to meet the energy demand value of the indoor devices. When the total energy demand value of multiple indoor devices is greater than the energy consumption threshold, only by increasing the output power of the second outdoor unit, the total output power of the outdoor units cannot meet the total energy demand value of the indoor devices. At this time, it is also necessary to adjust the operating parameters of the indoor devices to reduce the energy demand value of the indoor devices so that the total output power of the outdoor units is equal to the total energy demand value of the indoor devices.

[0096] Please refer to Figure 5 , Figure 5 which shows a flowchart of a defrosting control method for a multi-connected air conditioner system provided by an embodiment of the present application.

[0097] As Figure 5 shown, the above step S3000 at least includes the following steps:

[0098] Step S3100: When the total energy demand value of the indoor devices is greater than the energy consumption threshold and all the second outdoor units are in full-load operation, determine the reduction value of the total energy demand value of the indoor devices according to the difference between the total energy demand value of the indoor devices and the energy consumption threshold.

[0099] It can be understood that in the embodiments of the present application, the energy consumption threshold is set as the total maximum power of all outdoor units except the target outdoor unit. Therefore, when the total energy demand value of the indoor devices is greater than the energy consumption threshold, all outdoor units except the target outdoor unit in full-load operation still cannot meet the total energy demand value of the indoor devices. At this time, it is necessary to calculate the difference between the total energy demand value of the indoor devices and the energy consumption threshold to obtain the reduction value of the total energy demand value of the indoor devices, so as to reduce the energy consumption of the indoor devices on the premise of ensuring the user experience.

[0100] Step S3200: Adjust the operating parameters of the indoor devices according to the reduction value, so that the total output power of the second outdoor units is equal to the total sum of the total energy demand values of the indoor devices.

[0101] It can be understood that from the above steps, the indoor devices include indoor temperature control devices such as fan coil units, fresh air units, and radiant panels. After determining the reduction value of the total energy demand value of the indoor devices, it is necessary to adjust the operating parameters of the indoor devices, such as the opening degree of the air damper, the rotation speed of the fan, and the shutdown temperature of the indoor devices, to reduce the total sum of the total energy demand values of the indoor devices.

[0102] It can be understood that in order to avoid the reduction value of the total energy demand value of some indoor devices being too large and affecting the user experience, for example, the shutdown temperature of the indoor devices is too low, resulting in a sudden drop in room temperature, the rotation speed of the fan is too low or even stops, resulting in too slow indoor wind speed, and the opening degree of the air damper is too low, affecting indoor heating, etc., the reduction value of the total energy demand value of the indoor devices needs to be evenly distributed to each indoor device to maintain the stability of the indoor heating environment and also avoid frequent start and stop of the indoor devices, affecting the service life of the multi-connected air conditioner system.

[0103] Step S3300: Reduce the rotation speed of the fans of the indoor devices according to the reduction value.

[0104] It can be understood that, in order to ensure that the heating air outlet temperature of the indoor device remains stable, the air outlet is soft and the user experience is comfortable, while reducing the total energy demand value of the indoor device, the perception of temperature drop by the user is reduced by adjusting the fan speed of the indoor device. Specifically, when the set temperature of the air handling unit drops, reducing the fan speed can effectively prevent the air with a lower temperature from blowing onto the user, so that the user will not significantly perceive the temperature drop from the air handling unit, ensuring the heating effect indoors and the user experience.

[0105] Referring to Figure 6 , an embodiment of the second aspect of the present application further provides a refrigeration control device 500, including at least one control processor 510 and a memory 520 for communicatively connecting with the at least one control processor 510; the memory 520 stores instructions executable by the at least one control processor 510, and the instructions are executed by the at least one control processor 510 to enable the at least one control processor 510 to execute the defrost control method of the multi-connected air conditioner system as described above.

[0106] According to the refrigeration control device provided by the embodiment of the present application, it has at least the following beneficial effects: According to the total energy demand value of the indoor device and the total maximum output power of the outdoor unit, the target outdoor unit is controlled to enter the defrost mode, and the output power of the second outdoor unit and the total energy demand value of the indoor device are adjusted to avoid the situation that the outdoor unit cannot meet the energy demand value of the indoor device during the defrost process, resulting in unstable heating of the indoor device and ensuring the comfort of the user.

[0107] In a third aspect, an embodiment of the present application provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer-executable instructions for causing a computer to execute the control method of the first aspect embodiment.

[0108] According to the computer-readable storage medium provided by the embodiment of the present application, it has at least the following beneficial effects: According to the total energy demand value of the indoor device and the total maximum output power of the outdoor unit, the target outdoor unit is controlled to enter the defrost mode, and the output power of the second outdoor unit and the total energy demand value of the indoor device are adjusted to avoid the situation that the outdoor unit cannot meet the energy demand value of the indoor device during the defrost process, resulting in unstable heating of the indoor device and ensuring the comfort of the user.

[0109] Those of ordinary skill in the art will understand that all or some of the steps and systems disclosed above can be implemented as software, firmware, hardware, and appropriate combinations thereof. Some or all physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include a computer storage medium (or non-transitory medium) and a communication medium (or transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that communication media typically includes computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and can include any information delivery medium.

[0110] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0111] Although the embodiments of this application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of this application, and the scope of this application is defined by the claims and their equivalents.

Claims

1. A defrost control method for a multi-connected air conditioner system, characterized in that, the multi-connected air conditioner system includes a plurality of indoor devices and a plurality of cascaded outdoor units, the outdoor units include a main unit and slave units, and the defrost control method is applied to the main unit, and includes: when at least one of the outdoor units meets the defrost condition, determining the outdoor unit that needs to defrost as the first outdoor unit and the other outdoor units as the second outdoor units, and selecting one of the first outdoor units as the target outdoor unit to enter the defrost mode; when the total energy demand value of the plurality of indoor devices is less than or equal to the energy consumption threshold, increasing the output power of the second outdoor units so that the total output power of the outdoor units is equal to the total energy demand value of the indoor devices, wherein the energy consumption threshold is determined by the total maximum power of all the second outdoor units or the total maximum power of all the outdoor units except the target outdoor unit; when the total energy demand value of the plurality of indoor devices is greater than the energy consumption threshold, adjusting the operating parameters of the indoor devices to reduce the energy demand value of the indoor devices so that the total output power of the outdoor units is equal to the total energy demand value of the indoor devices.

2. The method according to claim 1, characterized in that, the defrost control method further includes: when the local unit meets the defrost condition, or when receiving a defrost request signal sent by the target outdoor unit, counting the total energy demand value of the plurality of indoor devices, wherein the defrost request signal indicates that the outdoor unit meets the defrost condition.

3. The method according to claim 1, characterized in that, the outdoor unit includes a hydraulic module, a refrigerant circulation module and a plate heat exchanger, the water outlet and water inlet of the plate heat exchanger are connected to the hydraulic module, and the refrigerant outlet and refrigerant inlet of the plate heat exchanger are connected to the refrigerant circulation module; when at least one of the outdoor units meets the defrost condition, determining the outdoor unit that needs to defrost as the first outdoor unit and the other outdoor units as the second outdoor units, includes: when the temperature of the refrigerant heat exchanger of the refrigerant circulation module of the outdoor unit is less than a preset first temperature threshold, or the heating duration of the refrigerant circulation module is greater than a preset time threshold, determining the outdoor unit as the first outdoor unit; when the temperature of the refrigerant heat exchanger of the refrigerant circulation module of the outdoor unit is greater than the first temperature threshold and the heating duration of the refrigerant circulation module is less than the time threshold, determining the outdoor unit as the second outdoor unit.

4. The method according to claim 3, characterized in that, selecting one of the first outdoor units as the target outdoor unit to enter the defrost mode, includes: determining the target outdoor unit according to the temperature of the refrigerant heat exchanger and the heating duration of the refrigerant circulation module; closing the pump body of the hydraulic module of the target outdoor unit, and controlling the refrigerant circulation module of the target outdoor unit to enter the defrost mode; when the water outlet temperature of the plate heat exchanger is lower than a preset second temperature threshold, starting the pump body.

5. The method according to claim 3, characterized in that, after controlling the target outdoor unit to enter the defrost mode, the defrost control method further includes: When the temperature of the refrigerant heat exchanger of the refrigerant circulation module is greater than a preset third temperature threshold, control the refrigerant circulation module of the target outdoor unit to enter the heating mode, where the third temperature threshold is greater than the first temperature threshold.

6. The method according to claim 1, wherein, the energy demand threshold is determined by the following method: According to the maximum output power of each of the outdoor units, determine the energy consumption threshold according to the total maximum power of all the second outdoor units, or determine the energy consumption threshold according to the total maximum power of all the outdoor units except the target outdoor unit.

7. The method according to claim 6, wherein, when the total energy demand value of multiple indoor devices is greater than the energy consumption threshold, adjust the operating parameters of the indoor devices to reduce the energy demand value of the indoor devices, so that the total output power of the outdoor units is equal to the total energy demand value of the indoor devices, including: Determine the increased value of the output power of the second outdoor unit according to the total energy demand value of the indoor devices and the total power output value of the outdoor units; Adjust the output power of the second outdoor unit according to the increased value.

8. The method according to claim 7, wherein, the increased values of the output powers of multiple second outdoor units are equal.

9. The method according to claim 6, wherein, when the total energy demand value of the indoor devices is greater than the energy consumption threshold, adjust the total energy demand value of the indoor devices and increase the output power of the second outdoor unit, so that the total output power of the second outdoor units is equal to the total energy demand value of the indoor devices, further including: When the total energy demand value of the indoor devices is greater than the energy consumption threshold, and when all the second outdoor units are in full-load operation, determine the reduced value of the total energy demand value of the indoor devices according to the difference between the total energy demand value of the indoor devices and the energy consumption threshold; Adjust the operating parameters of the indoor devices according to the reduced value, so that the total output power of the second outdoor units is equal to the total of the total energy demand values of the indoor devices.

10. The method according to claim 9, wherein, the indoor device is a air supply device, and the air supply device includes a fan; the adjusting the operating parameters of the indoor device according to the reduced value includes: Reducing the fan speed of the indoor device according to the reduced value.

11. A defrosting control device for a multi-connected air conditioner system, wherein, it includes at least one control processor and a memory for communicating with the at least one control processor; the memory stores instructions executable by the at least one control processor, and the instructions are executed by the at least one control processor so that the at least one control processor can execute the control method according to any one of claims 1 to 10.

12. A computer-readable storage medium, wherein, the computer-readable storage medium stores computer-executable instructions for causing a computer to execute the control method according to any one of claims 1 to 10.

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