CN110762787B - Defrosting control method of multi-split central air conditioning system - Google Patents
Defrosting control method of multi-split central air conditioning system Download PDFInfo
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- CN110762787B CN110762787B CN201910969389.3A CN201910969389A CN110762787B CN 110762787 B CN110762787 B CN 110762787B CN 201910969389 A CN201910969389 A CN 201910969389A CN 110762787 B CN110762787 B CN 110762787B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
- F24F11/63—Electronic processing
- F24F11/64—Electronic processing using pre-stored data
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
- F24F11/41—Defrosting; Preventing freezing
- F24F11/42—Defrosting; Preventing freezing of outdoor units
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/70—Control systems characterised by their outputs; Constructional details thereof
- F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
- F24F11/83—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers
- F24F11/84—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers using valves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F2140/00—Control inputs relating to system states
- F24F2140/20—Heat-exchange fluid temperature
Abstract
The invention relates to a defrosting control method of a multi-split central air-conditioning system, wherein the multi-split central air-conditioning system comprises an outdoor unit, a plurality of indoor units and a plurality of water machines, a compressor, a control valve and an outdoor heat exchanger are installed in the outdoor unit, an air side heat exchange branch connected between the outdoor heat exchanger and the control valve in series is arranged in each indoor unit, a water side heat exchange branch connected with the air side heat exchange branch in parallel is arranged in each water machine, the air side heat exchange branch comprises an indoor heat exchanger and a first electronic expansion valve which are connected in series, and the water side heat exchange branch comprises a water side heat exchanger and a second electronic expansion valve which are: when the multi-split central air-conditioning system meets the defrosting condition, the control valve controls the communication between the exhaust port of the compressor and the outdoor heat exchanger, the communication between the suction port of the compressor and both the indoor heat exchanger and the water side heat exchanger, and opens a plurality of second electronic expansion valves; and controlling the plurality of first electronic expansion valves to be opened or closed according to the total operating heat capacities of the plurality of indoor machines or the total operating heat capacities of the plurality of water machines.
Description
Technical Field
The invention relates to the technical field of multi-split air conditioners, in particular to a defrosting control method of a multi-split central air conditioning system.
Background
The air conditioner is a household appliance commonly used in daily life of people, when the air conditioner carries out refrigeration or heating, a refrigerant of a condenser in the air conditioner carries out heat release, a refrigerant of an evaporator in the air conditioner carries out heat absorption, the refrigerant in the evaporator absorbs heat (cools) from air, and if the heat dissipation of the evaporator is poor, the evaporator is frosted; and the air conditioner is not defrosted in time, channels among the fins are blocked, the flow resistance of air and the thermal resistance of the evaporator are increased, the heat exchange capability is reduced, and the energy efficiency ratio of the air conditioner is reduced.
In order to solve the above-mentioned defrosting problem, taking a multi-split central air conditioning system as an example, the existing multi-split central air conditioning system adopts a four-way valve to convert the flow direction of refrigerant, and the heat exchanger of the indoor unit is switched from a condenser to an evaporator to absorb heat from indoor air and supply the heat exchanger in the outdoor unit for defrosting. The heat exchange of the heat exchanger of the indoor unit causes the temperature of indoor air to be reduced, and the indoor comfort is reduced.
Disclosure of Invention
The invention provides a defrosting control method of a multi-split central air-conditioning system, which is used for solving the problem of reduced indoor comfort caused by defrosting of the existing multi-split central air-conditioning system.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a defrosting control method of a multi-split central air-conditioning system, the multi-split central air-conditioning system comprises an outdoor unit, a plurality of indoor units and a plurality of water machines exchanging heat with water, a compressor, a control valve and an outdoor heat exchanger are installed in the outdoor unit, a wind side heat exchange branch connected in series between the outdoor heat exchanger and the control valve is arranged in the indoor unit, the wind side heat exchange branches are connected in parallel, a water side heat exchange branch connected in parallel with the wind side heat exchange branch is arranged in the water machines, the water side heat exchange branches are connected in parallel, the wind side heat exchange branch comprises an indoor heat exchanger and a first electronic expansion valve which are connected in series, the first electronic expansion valve is positioned between the indoor heat exchanger and the outdoor heat exchanger, the water side heat exchange branch comprises a water side heat exchanger and a second electronic expansion valve which are connected in series, the second electronic expansion valve is located between the water side heat exchanger and the outdoor heat exchanger, the control valve is used for controlling the communication between the exhaust port of the compressor and the outdoor heat exchanger, the communication between the suction port of the compressor and the indoor heat exchanger and the water side heat exchanger, or the communication between the exhaust port of the compressor and the indoor heat exchanger, the communication between the suction port of the compressor and the outdoor heat exchanger, and the defrosting control method comprises the following steps: a first regulation step: when the multi-split central air-conditioning system meets defrosting conditions, the control valve controls the communication between the exhaust port of the compressor and the outdoor heat exchanger, the communication between the suction port of the compressor and the indoor heat exchanger and the communication between the suction port of the compressor and the water side heat exchanger, and opens the plurality of second electronic expansion valves; a second regulation and control step: according to a plurality ofThe total operation heat capacity of the indoor unit or the total operation heat capacities of the plurality of water machines control the plurality of first electronic expansion valves to be opened or closed; wherein a total operating heat capacity Σ H of the plurality of indoor unitsiu(M) satisfying: sigma Hiu(M)＝Hiu(1)+ Hiu(2)+…+Hiu(i)+…+Hiu(M)，Hiu(i)＝Q1(i)×1M is the total number of the indoor units, Hiu(i) Is the operating heat capacity of the i-th indoor unit, Q1(i) Is the rated capacity of the i-th indoor unit,1the temperature return difference coefficient of the indoor unit is obtained; total operating heat capacity Σ H of a plurality of said water machineswm(N) satisfies: sigma Hwm(N)＝Hwm(1)+Hwm(2)+…+Hwm(j)+…Hwm(N)， Hwm(j)＝Q2(j)×2N is the total number of the water machines, Hwm(j) Is the operating heat capacity, Q, of the jth water machine2(j) Is the rated capacity of the jth water machine,2is the temperature return difference coefficient of the water machine.
Compared with the prior art, the defrosting control method of the multi-split central air-conditioning system provided by the invention has the advantages that when the multi-split central air-conditioning system meets defrosting conditions, the control valve controls the communication between the exhaust port of the compressor and the outdoor heat exchanger, the air suction port of the compressor and both the indoor heat exchanger and the water side heat exchanger, and opens the second electronic expansion valve in the water machine in the multi-split central air-conditioning system, and the water side heat exchanger exchanges heat with hot water; and according to the total operation heat capacity of a plurality of indoor units or the total operation heat capacity of a plurality of water machines, the defrosting capacity of the indoor units or the defrosting capacity of the water machines are known, if the defrosting capacity of the indoor units is poor and the defrosting capacity of the water machines is good, the first electronic expansion valve is controlled to be closed, and only the water side heat exchanger is adopted for absorbing heat; if the defrosting capacity of the water machine is poor or the defrosting capacity of the indoor machine is good, the second electronic expansion valve is controlled to be opened, meanwhile, the indoor heat exchanger and the water side heat exchanger are adopted to absorb heat, the influence on the comfort level of indoor air is small, and the defrosting efficiency is high.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a connection diagram of components of a multi-split central air-conditioning system according to an embodiment of the present invention;
fig. 2 is a schematic flow chart illustrating a defrosting control method of a multi-split central air-conditioning system according to an embodiment of the invention;
fig. 3 is a schematic diagram illustrating a water circuit control flow in a defrosting control method of a multi-split central air-conditioning system according to an embodiment of the invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be a mechanical connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In the description of the present invention, "and/or" is only one kind of association relationship describing an association object, and means that there may be three kinds of relationships, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.
The defrosting control method of the multi-connected central air-conditioning system of the embodiment of the invention comprises an outdoor unit 1, a plurality of indoor units 2 exchanging heat with the air in the multi-connected central air-conditioning system and a plurality of water machines 3 exchanging heat with water, wherein a compressor 11, a control valve 12 and an outdoor heat exchanger 13 are installed in the outdoor unit 1, a wind side heat exchange branch 20 connected in series between the outdoor unit 1 heat exchanger and the control valve 12 is arranged in the indoor unit 2, the plurality of wind side heat exchange branches 20 are connected in parallel, a water side heat exchange branch 30 connected in parallel with the wind side heat exchange branch 20 is arranged in the water machines 3, the plurality of water side heat exchange branches 30 are connected in parallel, the wind side heat exchange branch 20 comprises an indoor heat exchanger 21 and a first electronic expansion valve 22 connected in series, the first electronic expansion valve 22 is arranged between the indoor heat exchanger 21 and the outdoor heat exchanger 13, the water side heat exchange branch 30 comprises a water side heat exchanger, the second electronic expansion valve 32 is located between the water side heat exchanger 31 and the outdoor heat exchanger 13, the control valve 12 is used for controlling the communication between the exhaust port of the compressor 11 and the outdoor heat exchanger 13, and the communication between the suction port of the compressor 11 and both the indoor heat exchanger 21 and the water side heat exchanger 31, or the control valve 12 is used for controlling the communication between the exhaust port of the compressor 11 and both the indoor heat exchanger 21 and the water side heat exchanger 31, and the communication between the suction port of the compressor 11 and the outdoor heat exchanger 13, as shown in fig. 1. The defrosting control method comprises the following steps:
a first regulation step: when the multi-split central air-conditioning system meets the defrosting condition, the control valve 12 controls the exhaust port of the compressor 11 to be communicated with the outdoor heat exchanger 13, the suction port of the compressor 11 to be communicated with both the indoor heat exchanger 21 and the water side heat exchanger 31, and opens the plurality of second electronic expansion valves 32. According to a detection device (such as a temperature sensor and a pressure sensor) in the multi-split central air-conditioning system, parameters such as pressure and temperature of the refrigerant in the outdoor heat exchanger 13 are detected. The defrosting condition is that parameters such as pressure and temperature of the refrigerant in the outdoor heat exchanger 13 satisfy a preset range, and the preset range of the defrosting condition is the prior art and is not described herein again. The control valve 12 controls the communication between the exhaust port of the compressor 11 and the outdoor heat exchanger 13, the communication between the suction port of the compressor 11 and both the indoor heat exchanger 21 and the water side heat exchanger 31, and the operation of opening the second electronic expansion valve 32 can be controlled by a master controller in the multi-split central air-conditioning system or by a sub-controller in the multi-split central air-conditioning system.
A second regulation and control step: controlling the plurality of first electronic expansion valves 22 to be opened or closed according to the total operating heat capacities of the plurality of indoor machines 2 or the total operating heat capacities of the plurality of water machines 3; wherein the total operating heat capacity Σ H of the plurality of indoor units 2iu(M) satisfying: sigma Hiu(M)＝Hiu(1)+Hiu(2) +…+Hiu(i)+…+Hiu(M)，Hiu(i)＝Q1(i)×1M is the total number of indoor units 2, Hiu(i) Is the operating heat capacity, Q, of the i-th indoor unit 21(i) The rated capacity of the i-th indoor unit 2,1the temperature return difference coefficient of the indoor unit 2;
total operating heat capacity Σ H of multiple water machines 3wm(N) satisfies: sigma Hwm(N)＝Hwm(1)+ Hwm(2)+…+Hwm(j)+…Hwm(N)，Hwm(j)＝Q2(j)×2N is the total number of the water machine 3, Hwm(j) Is the operating heat capacity, Q, of the jth water machine 32(j) Is the rated capacity of the jth water machine 3,2the temperature return difference coefficient of the water machine 3. The general controller or the sub-controller further includes a calculating module, which is used for calculating the total operating heat capacity of the indoor units 2 or the rated total operating heat capacity of the water machines 3, and controlling the first electronic expansion valve 22 to be opened or closed according to the calculation result of the calculating module.
Compared with the prior art, the defrosting control method of the multi-split central air-conditioning system provided by the invention has the advantages that when the multi-split central air-conditioning system meets defrosting conditions, the control valve 12 controls the exhaust port of the compressor 11 to be communicated with the outdoor heat exchanger 13, the air suction port of the compressor 11 to be communicated with both the indoor heat exchanger 21 and the water side heat exchanger 31, the second electronic expansion valve 32 in the water machine 3 in the multi-split central air-conditioning system is opened, and the water side heat exchanger 31 exchanges heat with hot water; and according to the total operating heat capacity of the indoor units 2 or the total operating heat capacity of the water machines 3, the defrosting capacity of the indoor units 2 or the defrosting capacity of the water machines 3 is known, if the defrosting capacity of the indoor units 2 is poor and the defrosting capacity of the water machines 3 is good, the first electronic expansion valve 22 is controlled to be closed, and only the water side heat exchanger 31 is adopted for absorbing heat; if the defrosting capacity of the water machine 3 is poor or the defrosting capacity of the indoor unit 2 is good, the first electronic expansion valve 31 is controlled to be opened, and meanwhile, the indoor heat exchanger 21 and the water side heat exchanger 31 are adopted to absorb heat, so that the influence on the comfort level of indoor air is small, and the defrosting efficiency is high.
Further, referring to fig. 2, the second adjusting and controlling step specifically includes:
when the total operating heat capacity Σ H of the plurality of water machines 3wm(N) is less than or equal to the rated capacity Q of the outdoor unit 1wFirst preset capacity back difference multiple01Or total operating heat capacity Σ H of the indoor units 2iu(M) is greater than or equal to the rated capacity Q of the outdoor unit 1wSecond preset capacity back difference multiple02When this occurs, the first electronic expansion valve 22 is opened.
When the total operating heat capacity Σ H of the plurality of water machines 3wm(N) is larger than the rated capacity Q of the outdoor unit 1wFirst preset capacity back difference multiple01And the total operating heat capacity Σ H of the plurality of indoor units 2iu(M) is smaller than the rated capacity Q of the outdoor unit 1wSecond preset capacity back difference multiple02When so, the first electronic expansion valve 22 is closed.
In summary, if the total operating heat capacity Σ H of the multiple water machines 3wm(N) is less than or equal to the rated capacity Q of the outdoor unit 1wFirst preset capacity back difference multiple01In time, it indicates that the defrosting capacity of the plurality of water machines 3 is weak; if the total operating heat capacity Σ H of the plurality of indoor units 2iu(M) is greater than or equal to the rated capacity Q of the outdoor unit 1wSecond preset capacity back difference multiple02It indicates that the defrosting capacity of the plurality of indoor units 2 is strong. So when the total operation heat capacity Sigma H of a plurality of water machines 3wm(N) is less than or equal to outdoor unitRated capacity Q of 1wFirst preset capacity back difference multiple01Or total operating heat capacity Σ H of the indoor units 2iu(M) is greater than or equal to the rated capacity Q of the outdoor unit 1wSecond preset capacity back difference multiple02When the first electronic expansion valve 22 is opened, the water side heat exchangers 31 of the plurality of water machines 3 exchange heat with water, and the indoor heat exchangers 21 of the plurality of indoor machines 2 exchange heat with indoor air, so as to ensure the defrosting speed of the outdoor heat exchanger 13. If the total operating heat capacity Σ H of the plurality of water machines 3wm(N) is larger than the rated capacity Q of the outdoor unit 1wFirst preset capacity back difference multiple01The defrosting capacity of the plurality of water machines 3 is stronger; if the total operating heat capacity Σ H of the plurality of indoor units 2iu(M) is smaller than the rated capacity Q of the outdoor unit 1wSecond preset capacity back difference multiple02It indicates that the defrosting capability of the plurality of indoor units 2 is weak. So when the total operation heat capacity Sigma H of a plurality of water machines 3wm(N) is larger than the rated capacity Q of the outdoor unit 1wFirst preset capacity back difference multiple01And the total operating heat capacity Σ H of the plurality of indoor units 2iu(M) is smaller than the rated capacity Q of the outdoor unit 1wSecond preset capacity back difference multiple02In the meantime, the first electronic expansion valve 22 is closed, only the second electronic expansion valve 32 is opened, and the water side heat exchangers 31 of the plurality of water machines 3 exchange heat with water, so that the heat exchange efficiency is high, and the defrosting speed of the heat exchangers in the outdoor unit 1 is high.
The first preset capacity return difference multiple01The value range of (1) is 0.4-0.5, and the return difference multiple of the second preset capacity02The value range of (A) is 0.7-0.8.
Further, after the second adjusting and controlling step, the method further comprises the following steps:
and (3) circulating step: after a first predetermined time t1And then returning to the first regulation and control step.
The master controller or the sub-controller further comprises a timing module, and the timing module records the accumulated time after the second regulation and control step is executed. When the accumulated time recorded by the timing module reaches a first preset time t1Then, the first regulation and control step is returned, so that the regulation and control can be carried out according to different time periodsAnd the load condition of the multi-split central air-conditioning system correspondingly regulates and controls the defrosting mode adopted by the multi-split central air-conditioning system, so that the influence on the comfort level of the indoor air in the whole defrosting process is small, and the defrosting efficiency is high. The first preset time t1Is taken as 10 s.
It should be noted that: the above-mentioned water side heat exchanger 31 includes a first heat exchange flow path and a second heat exchange flow path, the first heat exchange flow path is connected to the second electronic expansion valve 32, between the control valves 12, the multi-split central air-conditioning system further includes a control water valve 33, a water storage device 34 and a heating device 35, the control water valve 33 is used for controlling the water return port of the water storage device 34 to communicate with the inlet of the second heat exchange flow path, or controlling the water return port of the heating device 35 to communicate with the inlet of the second heat exchange flow path, the outlet of the second heat exchange flow path communicates with the water inlet of the water storage device 34, and the water inlet of the heating device 35, after the second electronic expansion valve 32 is opened, the defrosting control method further includes:
a water path regulation step: the control water valve 33 controls the inlet of the second heat exchange flow path to communicate with the return port of the water storage device 34 or the return port of the heating device 35, based on the water temperature in the water storage device 34, the water temperature in the heating device 35, or the water temperature in the water storage device 34 and the water temperature in the heating device 35.
A first temperature detection device, such as an electronic thermometer or a temperature sensor, is installed in the water storage device 34, and is used for detecting the temperature of water in the water storage device 34; similarly, a second temperature detection device is installed in the heating device 35, and the second temperature detection device is used for detecting the temperature of water in the heating device 35. The controller can control the water return port of the water storage device 34 to be communicated with the inlet of the second heat exchange flow path when the water temperature detected by the first temperature detection device is higher according to the water temperature detected by the first temperature detection device, the water temperature detected by the second temperature detection device or the water temperatures detected by the first temperature detection device and the second temperature detection device; when the water temperature detected by the second temperature detecting device is high, the water return port of the heating device 35 can be controlled to be communicated with the inlet of the second heat exchange flow channel. Therefore, the defrosting control method according to the embodiment of the present invention can control the water-side heat exchanger 31 to exchange heat with different water consumption devices according to the water temperature in the water storage device 34, the water temperature in the heating device 35, or the water temperature conditions in the water storage device 34 and the heating device 35, thereby reducing the influence on the indoor water consumption and achieving a high defrosting speed.
It should be noted that: temperature return difference coefficient of the indoor unit 21And satisfies the following conditions:1＝ (Tcl-Ti)/ΔT1，Tclis the refrigerant temperature value, T, in the indoor heat exchanger 21iIs the air temperature, delta T, at the return air inlet of the indoor unit 21The preset temperature difference value between the temperature value of the refrigerant in the indoor heat exchanger 21 and the return air temperature of the air at the return air inlet of the indoor unit 2 is obtained; when the water return port of the heating device 35 is communicated with the inlet of the second heat exchange flow path, the temperature return difference coefficient of the water machine 32And satisfies the following conditions:2＝(Twi-Tw0)/ΔTw，Twifor the return water temperature, T, of the heating installation 35w0A preset minimum water temperature for the heater 35; delta TwA preset temperature difference value between the return water temperature of the heating system 35 and a preset minimum water temperature of the heating system 35; when the water return port of the water storage device 34 is communicated with the inlet of the second heat exchange flow path, the temperature return difference coefficient of the water machine 32And satisfies the following conditions:2＝ (Tdhw-Td0)/ΔTd，Tdhwthe temperature of the water in the reservoir 34, Td0A preset minimum water temperature, Δ T, for the water reservoir 34dA predetermined temperature difference between the water temperature in the reservoir 34 and a predetermined minimum water temperature. The temperature parameters are detected by adopting temperature detection devices at corresponding positions; alternatively, the above Δ T1At 20 ℃ and Tw0At 25 ℃ and. delta.TwAt 10 ℃ Td0At 30 ℃ and. delta.TdIs 10 ℃.
Optionally, the waterway regulation and control step specifically includes:
the temperature of the water in the reservoir 34 is obtained. The general controller or sub-controller obtains the temperature of the water in the water reservoir 34 from the first temperature sensing device.
When the water temperature is higher than the preset temperature threshold, the control water valve 33 controls the water return port of the water storage device 34 to be communicated with the inlet of the second heat exchange flow path, and the water return port of the heating device 35 to be disconnected from the inlet of the second heat exchange flow path.
When the water temperature is less than or equal to the preset temperature threshold, the control water valve 33 controls the water return port of the heating device 35 to be communicated with the inlet of the second heat exchange flow path, and the water return port of the water storage device 34 to be disconnected with the inlet of the second heat exchange flow path.
The defrosting control method of the embodiment of the invention preferentially controls the connection or disconnection of the water return port of the water storage device 34 and the inlet of the second heat exchange flow path through the control water valve 33 according to the water temperature in the water storage device 34. Because the water in the water storage device 34 is used as primary water, when the multi-split central air-conditioning system performs defrosting, the water temperature in the water storage device 34 is reduced, and indoor heating is not influenced; after defrosting is complete, the temperature of the water in the reservoir 34 can be increased again. Of course, the control water valve 33 may control the connection or disconnection of the water return port of the heating device 35 and the inlet of the second heat exchange flow path according to the actual need and the water temperature in the heating device 35.
It is considered that a part of the water temperature of the water reservoir 34 or the heater 35 may be low after defrosting of the multi-split central air conditioning system for a certain period of time, so that the water reservoir 34 or the heater 35 may be frozen. Therefore, referring to fig. 3, the defrosting control method according to the embodiment of the present invention further includes, after the step of regulating the water path:
and (3) anti-freezing regulation and control step: and if the return water temperature parameter of any water storage device 34 exceeds the first preset return water temperature parameter range and the return water temperature parameter of any heating device 35 exceeds the second preset return water temperature parameter range, controlling the corresponding second electronic expansion valve 32 to be closed.
Knowing the current temperature reduction condition of the water in the water storage device 34 according to the return water temperature parameter of the water storage device 34, and when the return water temperature parameter of a certain water storage device 34 exceeds a first preset return water temperature parameter range, indicating that the water temperature in the water storage device 34 is lower, the water storage device 34 may have a freezing risk, so that the second electronic expansion valve 32 is controlled to be correspondingly closed; the current temperature reduction condition of the water in the heating device 35 is known according to the return water temperature parameter of the heating device 35, and when the return water temperature parameter of a certain heating device 35 exceeds the second preset return water temperature parameter range, it indicates that the temperature of the water in the heating device 35 is low, and the heating device 35 may be in a freezing risk, so that the second electronic expansion valve 32 is controlled to be correspondingly closed.
Further, the anti-freezing regulation and control step specifically comprises the following steps:
spaced by a second preset time t2If the return water temperature parameter of any one of the water storage devices 34 exceeds the first preset return water temperature parameter range or the return water temperature parameter of any one of the heating devices 35 exceeds the second preset return water temperature parameter range, the corresponding second electronic expansion valve 32 is controlled to be closed.
The timing module of the master controller or the sub-controller is further configured to record the accumulated time after the control of the water valve 33 is performed, and when the accumulated time recorded by the timing module reaches the second preset time t2When the temperature control method is used, if the return water temperature parameter of any water storage device 34 exceeds the first preset return water temperature parameter range or any return water temperature parameter of the heating device 35 exceeds the second preset return water temperature parameter range, the second electronic expansion valve 32 is controlled to be closed correspondingly, so that the second electronic expansion valve can be controlled to be opened and closed correspondingly according to the return water temperature parameter in the water storage device 34, the return water temperature parameter in the heating device 35, the water temperature in the water storage device 34 and the return water temperature parameter in the heating device 35 in time, and the freezing risk of any water storage device 34 or heating device 35 is prevented. The second preset time t2Is 30s or 60 s.
Optionally, the return water temperature parameter is a return water temperature, and the first preset temperature parameter range is a return water temperature T of the water storage device 34swiIs greater than or equal to the first preset backwater temperature Tswi0The second preset backwater temperature parameter range is the backwater temperature T of the heating device 35dwiGreater than or equal to the second preset backwater temperature Tdwi0. A first return water temperature detection device for detecting a return water temperature T of the water storage device 34 is installed in a return water pipe of the water storage device 34swiA second return water temperature detection device is installed in the return water pipe of the heating device 35, and the second return water temperature detection device is used for detecting the return water temperature of the water storage device 34Degree Tdwi。
Optionally, the return water temperature parameter is a return water temperature decrease rate, and the first preset return water temperature parameter range is a return water temperature decrease rate η of the water storage device 34swiLess than the first preset return water temperature decrease rate etas0The second preset backwater temperature parameter range is the backwater temperature reduction rate eta of the heating device 35dwiLess than the second preset return water temperature decrease rate etad0. The general controller or the sub-controller calculates the return water temperature reduction rate of the water storage device 34 or the heating device 35 according to the return water temperature of the water storage device 34 or the heating device 35. The return water temperature decrease rate eta of the water storage device 34swiAnd satisfies the following conditions: etaswi＝(Tswi(i-1)-Tswi(i))/t2，Tswi(i-1) Return Water temperature, T, of the last reservoir 34swi(i) The water return temperature of the present water reservoir 34. Accordingly, the return water temperature decrease rate η of the heater 35dwiAnd satisfies the following conditions: etadwi＝(Tdwi (j-1)-Tdwi(j))/t2，Tdwi(j-1) the return water temperature, T, of the last heating system 35dwi(j) The water return temperature of the heating device 35 at this time.
The water storage device 34 may be a water tank, the heater 35 may be a floor heater, the control valve 12 may be a four-way valve, and the control water valve 33 may be a three-way valve. In addition, the multi-split central air conditioning system further comprises a gas-liquid separator 14 and a water pump 36, wherein the gas-liquid separator 14 is connected in series between the air suction port of the compressor 11 and the control valve 12, and the water pump 36 is connected in series between the three-way valve and the outlet of the second heat exchange flow channel in the water side heat exchanger 31.
In some embodiments, the first adjusting step specifically includes:
when the multi-split central air-conditioning system meets the defrosting condition, the control valve 12 controls the exhaust port of the compressor 11 to be communicated with the outdoor heat exchanger 13, the suction port of the compressor 11 to be communicated with both the indoor heat exchanger 21 and the water side heat exchanger 31, and obtains defrosting permission information of a user. And knowing the defrosting permission condition of the user according to control information sent by a sub-controller operated by the user.
If the defrosting permission information indicates that defrosting by the water machine 3 is permitted (i.e., the user's defrosting permission is Y in fig. 2), the plurality of second electronic expansion valves 32 are opened.
If the defrosting permission information indicates that defrosting is permitted only with the indoor unit 2 (i.e., the user's defrosting permission in fig. 2 is N), the plurality of first electronic expansion valves 22 are opened.
In the defrosting control method of the embodiment, the user can freely select the defrosting method according to the water consumption, heat consumption and preference of the user, so as to meet the actual requirements of the user and enlarge the application range.
In the description herein, particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.
The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (9)
1. A defrosting control method of a multi-split central air-conditioning system comprises an outdoor unit, a plurality of indoor units and a plurality of water machines exchanging heat with water, wherein a compressor, a control valve and an outdoor heat exchanger are installed in the outdoor unit, a wind side heat exchange branch connected in series between the outdoor heat exchanger and the control valve is arranged in the indoor unit, the wind side heat exchange branches are connected in parallel, a water side heat exchange branch connected in parallel with the wind side heat exchange branch is arranged in the water machines, the water side heat exchange branches are connected in parallel, the wind side heat exchange branch comprises an indoor heat exchanger and a first electronic expansion valve which are connected in series, the first electronic expansion valve is positioned between the indoor heat exchanger and the outdoor heat exchanger, the water side heat exchange branch comprises a water side heat exchanger and a second electronic expansion valve which are connected in series, and the second electronic expansion valve is positioned between the water side heat exchanger and the outdoor heat exchanger, the control valve is used for controlling the communication between the exhaust port of the compressor and the outdoor heat exchanger, the communication between the suction port of the compressor and the indoor heat exchanger and the communication between the exhaust port of the compressor and the indoor heat exchanger and the communication between the discharge port of the compressor and the communication between the suction port of the compressor and the outdoor heat exchanger, and the defrosting control method is characterized by comprising the following steps:
a first regulation step: when the multi-split central air-conditioning system meets defrosting conditions, the control valve controls the communication between the exhaust port of the compressor and the outdoor heat exchanger, the communication between the suction port of the compressor and the indoor heat exchanger and the communication between the suction port of the compressor and the water side heat exchanger, and opens the plurality of second electronic expansion valves;
a second regulation and control step: controlling the plurality of first electronic expansion valves to be opened or closed according to the total operating heat capacities of the plurality of indoor machines or the total operating heat capacities of the plurality of water machines;
wherein a total operating heat capacity Σ H of the plurality of indoor unitsiu(M) satisfying: sigma Hiu(M)＝Hiu(1)+Hiu(2)+…+Hiu(i)+…+Hiu(M)，Hiu(i)＝Q1(i)×1M is the total number of the indoor units, Hiu(i) Is the operating heat capacity of the i-th indoor unit, Q1(i) Is the rated capacity of the i-th indoor unit,1the temperature return difference coefficient of the indoor unit is obtained;
total operating heat capacity Σ H of a plurality of said water machineswm(N) satisfies: sigma Hwm(N)＝Hwm(1)+Hwm(2)+…+Hwm(j)+…Hwm(N)，Hwm(j)＝Q2(j)×2N is the total number of the water machines, Hwm(j) Is the operating heat capacity, Q, of the jth water machine2(j) Is the rated capacity of the jth water machine,2the temperature return difference coefficient of the water machine is obtained;
the second regulating step specifically comprises:
when the total operating heat capacity of the plurality of water machines is smaller than or equal to a first preset capacity return difference multiple of the rated capacity of the outdoor unit or the total operating heat capacity of the plurality of indoor units is larger than or equal to a second preset capacity return difference multiple of the rated capacity of the outdoor unit, opening the first electronic expansion valve;
and when the total operating heat capacity of the plurality of water machines is larger than a first preset capacity return difference multiple of the rated capacity of the outdoor unit and the total operating heat capacity of the plurality of indoor units is smaller than a second preset capacity return difference multiple of the rated capacity of the outdoor unit, closing the first electronic expansion valve.
2. The defrosting control method of a multi-split central air conditioning system as set forth in claim 1, further comprising, after the second regulating step:
and (3) circulating step: and after the first preset time, returning to the first regulation and control step.
3. A defrosting control method for a multi-split central air conditioning system as claimed in claim 1, wherein the water side heat exchanger includes a first heat exchange flow path and a second heat exchange flow path that exchange heat with each other, the first heat exchange flow path is connected between the second electronic expansion valve and the control valve, the multi-split central air conditioning system further includes a control water valve, a water storage device and a heating device, the control water valve is used to control an inlet of the second heat exchange flow path to communicate with a water return port of the water storage device or a water return port of the heating device, an outlet of the second heat exchange flow path communicates with both a water inlet of the water storage device and a water inlet of the heating device, and after the second electronic expansion valve is opened, the defrosting control method further includes:
a water path regulation step: and according to the water temperature in the water storage device and/or the water temperature in the heating device, the control water valve controls the inlet of the second heat exchange flow path to be communicated with the water return port of the water storage device or the water return port of the heating device.
4. The defrosting control method of a multi-split central air-conditioning system according to claim 3, wherein the water path adjusting and controlling step specifically includes:
acquiring the water temperature in the water storage device;
when the water temperature is greater than a preset temperature threshold value, the control water valve controls a water return port of the water storage device to be communicated with an inlet of the second heat exchange flow path and a water return port of the heating device to be disconnected with the inlet of the second heat exchange flow path;
and when the water temperature is less than or equal to a preset temperature threshold value, the control water valve controls the water return port of the heating device to be communicated with the inlet of the second heat exchange flow path and the water return port of the water storage device to be disconnected with the inlet of the second heat exchange flow path.
5. The defrosting control method of a multi-split central air conditioning system as set forth in claim 3, further comprising, after the water path adjusting step:
and (3) anti-freezing regulation and control step: and if the return water temperature parameter of any water storage device exceeds a first preset return water temperature parameter range or the return water temperature parameter of any heating device exceeds a second preset return water temperature parameter range, correspondingly controlling the second electronic expansion valve to be closed.
6. The defrosting control method of a multi-split central air-conditioning system according to claim 5, wherein the freezing prevention control step specifically includes:
and (4) if the backwater temperature parameter of any water storage device exceeds the first preset backwater temperature parameter range or the backwater temperature parameter of any heating device exceeds the second preset backwater temperature parameter range at the interval of second preset time, correspondingly controlling the second electronic expansion valve to be closed.
7. The defrosting control method of a multi-split central air-conditioning system according to claim 5 or 6, wherein the water return temperature parameter is a water return temperature, the first preset water return temperature parameter range is that the water return temperature of the water storage device is greater than or equal to a first preset water return temperature, and the second preset water return temperature parameter range is that the water return temperature of the heating device is greater than or equal to a second preset water return temperature.
8. The defrosting control method of a multi-split central air-conditioning system according to claim 5 or 6, wherein the return water temperature parameter is a return water temperature decrease rate, the first preset return water temperature parameter range is such that the return water temperature decrease rate of the water storage device is smaller than a first preset return water temperature decrease rate, and the second preset return water temperature parameter range is such that the return water temperature decrease rate of the heating device is smaller than a second preset return water temperature decrease rate.
9. The defrosting control method of a multi-split central air-conditioning system according to claim 1, wherein the first regulating step specifically includes:
when the multi-split central air-conditioning system meets defrosting conditions, the control valve controls the control valve to control the communication between the exhaust port of the compressor and the outdoor heat exchanger, and the communication between the suction port of the compressor and both the indoor heat exchanger and the water side heat exchanger, and obtains defrosting permission information of a user;
if the defrosting permission information indicates that the water machine is allowed to be used for defrosting, opening a plurality of second electronic expansion valves;
and if the defrosting permission information indicates that only the indoor unit is allowed to defrost, opening the plurality of first electronic expansion valves.
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| CN201910969389.3A CN110762787B (en) | 2019-10-12 | 2019-10-12 | Defrosting control method of multi-split central air conditioning system |
| PCT/CN2019/119563 WO2021068358A1 (en) | 2019-10-12 | 2019-11-20 | Multi-line defrosting control method |
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| CN201910969389.3A CN110762787B (en) | 2019-10-12 | 2019-10-12 | Defrosting control method of multi-split central air conditioning system |
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| CN111351248B (en) * | 2020-03-13 | 2021-10-08 | 海信（山东）空调有限公司 | Air conditioning system and control method |
| CN114440496A (en) * | 2022-01-26 | 2022-05-06 | 同济大学 | Air conditioner floor heating two-combined air source heat pump system |
| CN114963570A (en) * | 2022-04-18 | 2022-08-30 | 青岛经济技术开发区海尔热水器有限公司 | Defrosting control method, device, equipment and medium for heat pump water heater |
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| JP3596347B2 (en) * | 1998-04-15 | 2004-12-02 | 三菱電機株式会社 | Refrigeration air conditioner and control method thereof |
| EP2527751B1 (en) * | 2010-01-19 | 2019-08-07 | Mitsubishi Electric Corporation | Air conditioning-hot water supply combined system |
| JP2018109463A (en) * | 2016-12-28 | 2018-07-12 | 三菱重工サーマルシステムズ株式会社 | Controller of multiple-type air conditioner, multiple-type air conditioner, method of controlling multiple-type air conditioner, and control program for multiple-type air conditioner |
| EP3611439B1 (en) * | 2017-04-11 | 2023-08-02 | Hitachi-Johnson Controls Air Conditioning, Inc. | Air conditioner |
| CN107525174A (en) * | 2017-08-17 | 2017-12-29 | 青岛海信日立空调系统有限公司 | A kind of multi-online air-conditioning system and its control method |
| CN107477805B (en) * | 2017-09-12 | 2020-04-07 | 青岛海信日立空调系统有限公司 | Multi-split air-conditioning floor heating system and control method thereof |
| CN109237713B (en) * | 2018-09-25 | 2020-06-09 | 珠海格力电器股份有限公司 | Water multi-connected unit operation control method and device, medium and water multi-connected air conditioning system |
| CN109945399B (en) * | 2019-03-20 | 2020-03-10 | 珠海格力电器股份有限公司 | Defrosting method and air conditioner |
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