Multi-split air conditioning system and switching control method for operating mode of indoor units thereof

Abstract

A multi-split air conditioning system and a switching control method for an operating mode of indoor units thereof. The method comprises the following steps: when any indoor unit (21, 22, 23, 24) in multiple indoor units (21, 22, 23, 24) receives a mode switching instruction, the indoor unit (21, 22, 23, 24) sends the mode switching instruction to a shunt device (30) (S1); the shunt device (30) performs switching control on a heating control valve or a refrigeration control valve corresponding to the indoor unit (21, 22, 23, 24) according to the received mode switching instruction, releases pressure by controlling a second throttling assembly (34), a first control valve, and a bypass valve in order to reduce a differential pressure across the refrigeration control valve or the heating control valve corresponding to the indoor unit (21, 22, 23, 24), obtains a switching flag bit of a four-way valve, and controls the refrigeration control valve or the heating control valve corresponding to the indoor unit (21, 22, 23, 24) and the four-way valve according to the switching flag bit of the four-way valve (S2).

1 - 12 . (canceled) 
     
     
         13 . A method for controlling switching between operating modes of an indoor unit in a multi-split air conditioning system, wherein the multi-split air conditioning system comprises: an outdoor unit, a shunt device and a plurality of indoor units, the outdoor unit comprises: a compressor and a four-way valve, the shunt device further comprises:
 a first heat exchange component, a second heat exchange component, a first throttling component arranged between an outlet of a first heat exchange flow path of the first heat exchange component and an inlet of a first heat exchange flow path of the second heat exchange component, a second throttling component arranged between an outlet of a first heat exchange flow path of the second heat exchange component and an inlet of a second heat exchange flow path of the second heat exchange component, a bypass valve arranged between the outlet of the first heat exchange flow path of the second heat exchange component and a low pressure pipeline of the shunt device, and a heating control valve and a refrigeration control valve corresponding to each indoor unit in the plurality of indoor units, the first throttling component comprises a first control valve,   the method comprising:
 when any indoor unit in the plurality of indoor units receives a mode switching instruction, sending, by the indoor unit, the mode switching instruction to the shunt device; and 
 performing, by the shunt device,
 switching control on the heating control valve or the refrigeration control valve corresponding to the indoor unit according to the received mode switching instruction, 
 releasing a pressure by controlling the second throttling component, the first control valve and the bypass valve to reduce a differential pressure across the refrigeration control valve or the heating control valve corresponding to the indoor unit, 
 obtaining a switching flag bit of the four-way valve, and 
 controlling the refrigeration control valve or the heating control valve corresponding to the indoor unit and the four-way valve according to the switching flag bit of the four-way valve. 
 
   
     
     
         14 . The method according to  claim 13 , wherein the switching flag bit of the four-way valve comprises 0 and 1,
 when the switching flag bit of the four-way valve is 0, the operating mode of the multi-split air conditioning system is switched from a main refrigeration mode to a pure refrigeration mode, or switched from the main refrigeration mode to the main refrigeration mode, or switched from a main heating mode to a pure heating mode, or switched from the main heating mode to the main heating mode;   when the switching flag bit of the four-way valve is 1, the operating mode of the multi-split air conditioning system is switched from the main heating mode to the main refrigeration mode, or switched from the main refrigeration mode to the main heating mode, or switched from the main refrigeration mode to the pure heating mode, or switched from the main heating mode to the pure refrigeration mode.   
     
     
         15 . The method according to  claim 14 , wherein when determining by the shunt device that the indoor unit is switched from a heating mode to a refrigeration mode according to the received mode switching instruction, and the switching flag bit of the four-way valve is 0, the method comprises:
 after delay of a first preset time, controlling, by the shunt device, the heating control valve corresponding to the indoor unit to close, and controlling the second throttling component and the first control valve to be in an open state, and after delay of a second preset time, controlling, by the shunt device, the second throttling component and the first control valve to be in a closed state, and controlling the refrigeration control valve corresponding to the indoor unit to be in an open state; or   after delay of the first preset time, controlling, by the shunt device, the heating control valve corresponding to the indoor unit to close, and controlling the second throttling component and the bypass valve to be in an open state, and after delay of second preset time, controlling, by the shunt device, the second throttling component and the bypass valve to be in a closed state, and controlling the refrigeration control valve corresponding to the indoor unit to be in the open state.   
     
     
         16 . The method according to  claim 14 , wherein when determining by the shunt device that the indoor unit is switched from a heating mode to a refrigeration mode according to the received mode switching instruction, and the switching flag bit of the four-way valve is 1, the method comprises:
 after delay of a first preset time, controlling, by the shunt device, the heating control valve corresponding to the indoor unit to close, and controlling the second throttling component and the first control valve to be in an open state, and after delay of a second preset time, controlling, by the shunt device, the second throttling component and the first control valve to be in a closed state, controlling the refrigeration control valve corresponding to the indoor unit to be in an open state, and controlling the four-way valve to switch; or   after delay of the first preset time, controlling, by the shunt device, the heating control valve corresponding to the indoor unit to close, and controlling the second throttling component and the bypass valve to be in an open state, and after delay of the second preset time, controlling, by the shunt device, the second throttling component and the bypass valve to be in a closed state, controlling the refrigeration control valve corresponding to the indoor unit to be in the open state, and controlling the four-way valve to switch.   
     
     
         17 . The method according to  claim 14 , wherein when determining by the shunt device that the indoor unit is switched from a refrigeration mode to a heating mode according to the received mode switching instruction, and the switching flag bit of the four-way valve is 0, the method comprises:
 after delay of a first preset time, controlling, by the shunt device, the refrigeration control valve corresponding to the indoor unit to close, and controlling the second throttling component and the first control valve to be in an open state, and after delay of a second preset time, controlling, by the shunt device, the second throttling component and the first control valve to be in a closed state, and controlling the heating control valve corresponding to the indoor unit to be in an open state; or   after delay of a first preset time, controlling, by the shunt device, the refrigeration control valve corresponding to the indoor unit to close, and controlling the second throttling component and the bypass valve to be in an open state, after delay of the second preset time, controlling the second throttling component and the bypass valve to be in a closed state, and controlling the heating control valve corresponding to the indoor unit to be in the open state.   
     
     
         18 . The method according to  claim 14 , wherein when determining by the shunt device that the indoor unit is switched from a refrigeration mode to a heating mode according to the received mode switching instruction, and the switching flag bit of the four-way valve is 1, the method comprises:
 after delay of a first preset time, controlling, by the shunt device, the refrigeration control valve corresponding to the indoor unit to close, and controlling the second throttling component and the first control valve to be in an open state, and after delay of a second preset time, controlling, by the shunt device, the second throttling component and the first control valve to be in a closed state, controlling the heating control valve corresponding to the indoor unit to be in an open state, and controlling the four-way valve to switch; or   after delay of the first preset time, controlling, by the shunt device, the refrigeration control valve corresponding to the indoor unit to close, and controlling the second throttling component and the bypass valve to be in an open state, and after delay of a second preset time, controlling, by the shunt device, the second throttling component and the bypass valve to be in a closed state, controlling the heating control valve corresponding to the indoor unit to be in the open state, and controlling the four-way valve to switch.   
     
     
         19 . A multi-split air conditioning system, comprising:
 an outdoor unit, comprising a compressor and a four-way valve;   a plurality of indoor units; and   a shunt device, comprising: a first heat exchange component, a second heat exchange component, a first throttling component arranged between an outlet of a first heat exchange flow path of the first heat exchange component and an inlet of a first heat exchange flow path of the second heat exchange component, a second throttling component arranged between an outlet of a first heat exchange flow path of the second heat exchange component and an inlet of a second heat exchange flow path of the second heat exchange component, a bypass valve arranged between the outlet of the first heat exchange flow path of the second heat exchange component and a low pressure pipeline of the shunt device, and a heating control valve and a refrigeration control valve corresponding to each indoor unit in the plurality of indoor units, the first throttling component comprises a first control valve,   when any indoor unit in plurality of indoor units receives a mode switching instruction, the indoor unit is configured to send the mode switching instruction to the shunt device;
 the shunt device further comprises:
 a control module, configured to perform switching control on the heating control valve or the refrigeration control valve corresponding to the indoor unit according to the received mode switching instruction, release a pressure by controlling the second throttling component, the first control valve and the bypass valve to reduce a differential pressure across the refrigeration control valve or the heating control valve corresponding to the indoor unit, obtain a switching flag bit of the four-way valve, and control the refrigeration control valve or the heating control valve corresponding to the indoor unit and the four-way valve according to the switching flag bit of the four-way valve. 
 
   
     
     
         20 . The multi-split air conditioning system according to  claim 19 , wherein the switching flag bit of the four-way valve comprises 0 and 1,
 when the switching flag bit of the four-way valve is 0, an operating mode of the multi-split air conditioning system is switched from a main refrigeration mode to a pure refrigeration mode, or switched from the main refrigeration mode to the main refrigeration mode, or switched from a main heating mode to a pure heating mode, or switched from the main heating mode to the main heating mode;   when the switching flag bit of the four-way valve is 1, the operating mode of the multi-split air conditioning system is switched from the main heating mode to the main refrigeration mode, or switched from the main refrigeration mode to the main heating mode, or switched from the main refrigeration mode to the pure heating mode, or switched from the main heating mode to a pure refrigeration mode.   
     
     
         21 . The multi-split air conditioning system according to  claim 20 , wherein when the shunt device is configured to determine that the indoor unit is switched from a heating mode to a refrigeration mode according to the received mode switching instruction, and the switching flag bit of the four-way valve is 0, the control module is configured to:
 after delay of a first preset time, control the heating control valve corresponding to the indoor unit to close, and control the second throttling component and the first control valve to be in an open state, after delay of a second preset time, control the second throttling component and the first control valve to be in a closed state, and control the refrigeration control valve corresponding to the indoor unit to be in an open state; and   after delay of the first preset time, control the heating control valve corresponding to the indoor unit to close, and control the second throttling component and the bypass valve to be in an open state, after delay of the second preset time, control the second throttling component and the bypass valve to be in a closed state, and control the refrigeration control valve corresponding to the indoor unit to be in an open state.   
     
     
         22 . The multi-split air conditioning system according to  claim 20 , wherein when the shunt device is configured to determine that the indoor unit is switched from a heating mode to a refrigeration mode according to the received mode switching instruction, and the switching flag bit of the four-way valve is 1, the control module is configured to:
 after delay of a first preset time, control the heating control valve corresponding to the indoor unit to close, and control the second throttling component and the first control valve to be in an open state, after delay of a second preset time, control the second throttling component and the first control valve to be in a closed state, and control the refrigeration control valve corresponding to the indoor unit to be in an open state, and control the four-way valve to switch; or   after delay of the first preset time, control the heating control valve of corresponding to the indoor unit to close, and control the second throttling component and the bypass valve to be in an open state, after delay of the second preset time, control the second throttling component and the bypass valve to be in a closed state, and controls the refrigeration control valve corresponding to the indoor unit to be in an open state, and control the four-way valve to switch.   
     
     
         23 . The multi-split air conditioning system according to  claim 20 , wherein when the shunt device is configured to determine that the indoor unit is switched from a refrigeration mode to a heating mode according to the received mode switching instruction, and the switching flag bit of the four-way valve is 0, the control is configured to:
 after delay of a first preset time, control the refrigeration control valve corresponding to the indoor unit to close, and control the second throttling component and the first control valve to be in an open state, after delay of a second preset time, control the second throttling component and the first control valve to be in a closed state, and control the heating control valve corresponding to the indoor unit to be in an open state; and   after delay of the first preset time, control the refrigeration control valve corresponding to the indoor unit to close, and control the second throttling component and the bypass valve to be in an open state, after delay of the second preset time, control the second throttling component and the bypass valve to be in a closed state, and control the heating control valve corresponding to the indoor unit to be in the open state.   
     
     
         24 . The multi-split air conditioning system according to  claim 20 , wherein when the shunt device is configured to determine that the indoor unit is switched from a refrigeration mode to a heating mode according to the received mode switching instruction, and the switching flag bit of the four-way valve is 1, the control module is configured to:
 after delay of a first preset time, control the refrigeration control valve corresponding to the indoor unit to close, and control the second throttling component and the first control valve to be in an open state, after delay of a second preset time, control the second throttling component and the first control valve to be in a closed state, control the heating control valve corresponding to the indoor unit to be in an open state, and control the four-way valve to switch; or   after delay of the first preset time, control the refrigeration control valve corresponding to the indoor unit to close, and control the second throttling component and the bypass valve to be in an open state, after delay of the second preset time, control the second throttling component and the bypass valve to be in a closed state, control the heating control valve corresponding to the indoor unit to be in the open state, and control the four-way valve to switch.