Refrigeration apparatus

Abstract

A refrigeration apparatus ( 1 ) is disclosed which is provided with multiple systems of utilization-side heat exchangers ( 20, 30, 40 ) and in which liquid-side interunit piping lines ( 53, 54, 55 ) are combined into a single liquid-side interunit piping line in multiple systems of liquid lines. When the refrigeration apparatus ( 1 ) provides space heating of 100% heat recovery without the use of an outdoor heat exchanger ( 15 ), the flow of refrigerant in a refrigerant circuit ( 50 ) is stabilized even when the temperature of outside air is low, thereby preventing the capacity to provide refrigeration from decreasing. In addition, in order to prevent shutdown of the refrigeration apparatus ( 1 ) due to malfunction, a liquid refrigerant inflow passageway ( 66 ) is connected to a heat source-side liquid pipe ( 62 ) of an outdoor unit ( 10 ), the heat source-side liquid pipe ( 62 ) being connected to an integrated liquid pipe ( 53 ) of the liquid-side interunit piping lines ( 53, 54, 55 ), and to an inlet port of the a receiver ( 17 ), and a switch valve (SV 1 ) capable of being on-off controlled is disposed in the liquid refrigerant inflow passageway ( 66 ).

1 . A refrigeration apparatus comprising: a heat source-side unit ( 10 ) including a compression mechanism ( 11 D,  11 E), a heat source-side heat exchanger ( 15 ), and a receiver ( 17 ); a first utilization-side unit ( 30 ,  40 ) including a first utilization-side heat exchanger ( 31 ,  41 ); a second utilization-side unit ( 20 ) including a second utilization-side heat exchanger ( 21 ); and a gas-side interunit piping line ( 51 ,  52 ) and a liquid-side interunit piping line ( 53 ,  54 ,  55 ) which establish connections between each unit ( 10 ,  20 ,  30 ,  40 ) to thereby constitute a refrigerant circuit ( 50 );
 the gas-side interunit piping line ( 51 ,  52 ) including: a first gas-side interunit piping line ( 51 ) which is connected to the heat source-side unit ( 10 ) and to the first utilization-side unit ( 30 ,  40 ); and a second gas-side interunit piping line ( 52 ) which is connected to the heat source-side unit ( 10 ) and to the second utilization-side unit ( 20 );   the liquid-side interunit piping line ( 53 ,  54 ,  55 ) including: an integrated liquid pipe ( 53 ) which is connected to the heat source-side unit ( 10 ); a first branch liquid pipe ( 54 ) which diverges from the integrated liquid pipe ( 53 ) to connect to the first utilization-side unit ( 30 ,  40 ); and a second branch liquid pipe ( 55 ) which diverges from the integrated liquid pipe ( 53 ) to connect to the second utilization-side unit ( 20 );   wherein the refrigeration apparatus further comprises: a liquid refrigerant inflow passageway ( 66 ) which is connected to a heat source-side liquid pipe ( 62 ) of the heat source-side unit ( 10 ), the heat source-side liquid pipe ( 62 ) being connected to the integrated liquid pipe ( 53 ) of the liquid-side interunit piping line ( 53 ,  54 ,  55 ), and to an inlet port of the receiver ( 17 ); and a switch valve (SV 1 ) which is disposed in the liquid refrigerant inflow passageway ( 66 ) and which is capable of being on-off controlled.   
   
   
       2 . The refrigeration apparatus of  claim 1 , wherein a plurality of the second utilization-side units ( 20 ) are connected in parallel to the heat source-side unit ( 10 ). 
   
   
       3 . The refrigeration apparatus of  claim 1 ,
 wherein the first utilization-side unit ( 30 ,  40 ) is a cooling machine for providing compartment cooling and the heat source-side unit ( 10 ) and the first utilization-side unit ( 30 ,  40 ) together constitute a first system-side circuit ( 50 A) in which refrigerant is circulated in one direction; and   wherein the second utilization-side unit ( 20 ) is an air conditioning machine for providing indoor air conditioning and the heat source-side unit ( 10 ) and the second utilization-side unit ( 20 ) together constitute a second system-side circuit ( 50 B) in which refrigerant is reversibly circulated.   
   
   
       4 . The refrigeration apparatus of  claim 1 , wherein the refrigeration apparatus further comprises control means ( 95 ) for performing on-off control of the switch valve (SV 1 ) in response to the operation state. 
   
   
       5 . The refrigeration apparatus of  claim 4 , wherein the control means ( 95 ) is configured such that in an operation state in which the second utilization-side heat exchanger ( 21 ) functions as a condenser while the first utilization-side heat exchanger ( 31 ,  41 ) functions as an evaporator, the switch valve (SV 1 ) is placed either in the closed state if the discharge pressure of the compression mechanism ( 11 D,  11 E) is below a predetermined value or in the opened state if the discharge pressure of the compression mechanism ( 11 D,  11 E) increases to equal or exceed the predetermined value. 
   
   
       6 . The refrigeration apparatus of  claim 4 , wherein the control means ( 95 ) is configured such that in an operation state in which the second utilization-side heat exchanger ( 21 ) functions as a condenser while the first utilization-side heat exchanger ( 31 ,  41 ) functions as an evaporator, the switch valve (SV 1 ) is placed either in the closed state if the amount of liquid refrigerant accumulated in the second utilization-side heat exchanger ( 21 ) and the liquid-side interunit piping line ( 53 ,  54 ,  55 ) is below a predetermined value or in the opened state if it is estimated that the liquid refrigerant amount accumulated reaches the predetermined value or above. 
   
   
       7 . The refrigeration apparatus of  claim 4 , wherein the control means ( 95 ) is configured such that in an operation state in which the second utilization-side heat exchanger ( 21 ) functions as a condenser while the first utilization-side heat exchanger ( 31 ,  41 ) functions as an evaporator, the switch valve (SV 1 ) is placed either in the closed state if the temperature of liquid refrigerant in the second utilization-side heat exchanger ( 21 ) is below a predetermined value or in the opened state if the liquid refrigerant temperature increases to equal or exceed the predetermined value. 
   
   
       8 . The refrigeration apparatus of  claim 4 , wherein the control means ( 95 ) is configured such that in an operation state in which the second utilization-side heat exchanger ( 21 ) functions as a condenser while the first utilization-side heat exchanger ( 31 ,  41 ) functions as an evaporator, the switch valve (SV 1 ) is placed either in the closed state if the pressure of liquid refrigerant in the liquid-side interunit piping line ( 53 ,  54 ,  55 ) is below a predetermined value or in the opened state if the liquid refrigerant pressure increases to equal or exceed the predetermined value.