Air conditioning system

Abstract

An air conditioning system includes a heat-pump type cooling unit and an air-heating unit. On a first circulation path in the cooling unit, provided are a gas-liquid separator provided between an expansion valve and an evaporator for separating refrigerant supplied from the expansion valve into refrigerant gas and refrigerant liquid and sending the refrigerant liquid to the evaporator, a bypass path for flowing the refrigerant gas through the first circulation path with bypassing the evaporator, and a changeover valve for preventing the refrigerant liquid from flowing into the evaporator. In warming-up mode, only the refrigerant gas is circulated in a refrigeration cycle. According to the system, air-heating can be achieved by driving the cooling unit even under a condition where outside temperature is very low.

1 . An air conditioning system comprising
 a heat-pump type cooling unit including a first circulation path in which a first refrigerant circulates and   an air-heating unit including a second circulation path in which a second refrigerant circulates,
 wherein, 
 on the first circulation path, provided are
 a compressor for compressing the first refrigerant, 
 a condenser for heat-exchanging between the first refrigerant and the second refrigerant and radiating heat of the first refrigerant, 
 an expansion unit for expanding the first refrigerant, and 
 an evaporator for heat-exchanging between the first refrigerant expanded by the expansion unit and air to cool the air; 
 
 the air-heating unit achieves air-heating by using heat radiated by the condenser; and 
 the system further comprises
 a gas-liquid separator provided between the expansion unit and the evaporator for separating the first refrigerant supplied from the expansion unit into first refrigerant gas and first refrigerant liquid and sending the first refrigerant liquid to the evaporator, 
 a bypass path for flowing the first refrigerant gas through the first circulation path with bypassing the evaporator, and 
 a refrigerant liquid flow preventing unit for preventing the first refrigerant liquid from flowing into the evaporator. 
 
   
   
   
       2 . The air conditioning system according to  claim 1 , wherein,
 on the second circulation path, provided are
 a pump for circulating the second refrigerant, 
 a component container for arranging the condenser also on the second circulation path, 
 a heater core for heating air by heat-exchanging between the second refrigerant and the air, and 
 a radiator for radiating heat of the second refrigerant; and 
   the second refrigerant is fluid to achieve heat-exchanging with sensible heat change.   
   
   
       3 . The air conditioning system according to  claim 1 , wherein,
 a first orifice and a second orifice are capable of provided on the bypass path alternatively.   
   
   
       4 . The air conditioning system according to  claim 1 , wherein,
 the refrigerant liquid flow preventing unit is a changeover valve capable of moving between a first position and a second position,   when the changeover valve is set to the first position, the bypass path is communicated with the first circulation path and the first circulation path is blocked so as not to flow the first refrigerant liquid into the evaporator, and   when the changeover valve is set to the second position, the bypass path is communicated with the first circulation path and the first circulation path is opened so as to flow the first refrigerant liquid into the evaporator.   
   
   
       5 . The air conditioning system according to  claim 4 , wherein,
 the changeover valve has a first orifice to make the first refrigerant gas passing through at the first position and a second orifice to make the first refrigerant gas passing through at the first position, and   flowing resistance of the first orifice is set to be optimum for warming-up mode and flowing resistance of the second orifice is set to be optimum for heating/cooling mode.   
   
   
       6 . The air conditioning system according to  claim 1 , wherein,
 the bypass path passes through a position where the first refrigerant liquid is normally held within a refrigerant tank within the gas-liquid separator, and   the inside of the bypass path communicates with the inside of the refrigerant tank through an oil breed hole at the position.   
   
   
       7 . The air conditioning system according to  claim 1 , wherein,
 changeover between the warming-up mode, in which it is prevented that the first refrigerant liquid flows into the evaporator, and the heating mode, in which it is allowed that the refrigerant liquid flows into the evaporator, is done based on at least one of intake air temperature into the evaporator and refrigerant pressure at an inlet side of the compressor.