Cooling apparatus

Abstract

A cooling cycle includes a first refrigerant circuit, a second refrigerant circuit and the third refrigerant circuit and switches the refrigerant circulation between the refrigerant circuits according to cooling modes so that a plurality of evaporators is efficiently controlled and Coefficient of Performance (COP) is improved by including an ejector.

What is claimed is: 
     
         1 . A cooling apparatus comprising:
 a first refrigerant circuit configured to allow a refrigerant discharged from a compressor to flow to a suction side of the compressor by passing through a condenser, an ejector, and a vapor liquid separator;   a second refrigerant circuit configured to allow the refrigerant to be sucked into an inlet of the ejector to be circulated by passing through the ejector, the vapor liquid separator, a first expansion device, a first evaporator and a second evaporator; and   a third refrigerant circuit configured to allow the refrigerant passing through the ejector and the vapor liquid separator to be sucked into an inlet of the ejector by passing through a second expansion device and the second evaporator to bypass the first expansion device and the first evaporator,   wherein the ejector mixes a refrigerant discharged from the condenser in the first refrigerant circuit with a refrigerant discharged from the second evaporator to discharge to the vapor liquid separator.   
     
     
         2 . The cooling apparatus of  claim 1 , further comprising:
 a flow path switching device installed on a portion of a discharge side of the vapor liquid separator to allow a liquid refrigerant passing through the vapor liquid separator to flow through at least one of the second refrigerant circuit and the third refrigerant circuit.   
     
     
         3 . The cooling apparatus of  claim 2 , further comprising:
 a control unit configured to control the flow path switching for a refrigerant to flow through the second refrigerant circuit when power supply is started and to flow through the third refrigerant circuit when cooling through the second refrigerant circuit is completed.   
     
     
         4 . The cooling apparatus of  claim 1 , wherein the second refrigerant circuit is configured to allow a refrigerant passing through the first evaporator to pass through the second evaporator. 
     
     
         5 . The cooling apparatus of  claim 1 , wherein the ejector mixes a refrigerant discharged from the condenser and a refrigerant discharged from the second evaporator, increases a pressure of the mixed refrigerant, and discharges to the vapor liquid separator. 
     
     
         6 . The cooling apparatus of  claim 1 , wherein the vapor liquid separator separates a refrigerant discharged from the ejector into a vapor refrigerant and a liquid refrigerant, discharges the vapor refrigerant to the first refrigerant circuit, and discharges the liquid refrigerant to the second refrigerant circuit or the third refrigerant circuit. 
     
     
         7 . The cooling apparatus of  claim 5 , wherein the ejector comprises a nozzle configured to decompress and expand a refrigerant discharged from the condenser, a suction unit configured to suction a refrigerant discharged from the second evaporator, a mixing unit configured to mix a refrigerant introduced to the nozzle and a refrigerant introduced to the suction unit, and a diffuser configured to raise a pressure of a refrigerant mixed in the mixing unit. 
     
     
         8 . The cooling apparatus of  claim 1 , wherein the compressor comprises an inverter compressor configured to control the amount of a refrigerant flow by controlling a rotation. 
     
     
         9 . The cooling apparatus of  claim 1 , wherein the expansion device comprises at least one of a capillary, an electronic expansion valve and a capillary tube. 
     
     
         10 . The cooling apparatus of  claim 1 , further comprising:
 a third expansion device provided on a discharge unit of the condenser to increase a humidity of a refrigerant introduced to the ejector.   
     
     
         11 . The cooling apparatus of  claim 10 , further comprising:
 a Suction Line Heat Exchanger (SLHX) configured to exchange heat between the third expansion device and the suction unit of the compressor.   
     
     
         12 . The cooling apparatus of  claim 1 , wherein the first refrigerant circuit further comprises a heat exchanger configured to exchange heat between the discharge unit of the condenser and the suction unit of the compressor. 
     
     
         13 . The cooling apparatus of  claim 1 , wherein the second refrigerant circuit further comprises an intermediate expansion device provided on a discharge unit of the first evaporator to decompress a refrigerant flowing in the second evaporator. 
     
     
         14 . The cooling apparatus of  claim 13 , wherein an internal diameter of the intermediate expansion device is smaller than an internal diameter of a refrigerant pipe disposed on a suction side of the compressor. 
     
     
         15 . The cooling apparatus of  claim 14 , wherein the internal diameter of the intermediate expansion device is approximately 2˜4 mm. 
     
     
         16 . A cooling apparatus comprising:
 a main refrigerant circuit provided with a vapor liquid separator separating a refrigerant into a vapor refrigerant and a liquid refrigerant, a compressor compressing a refrigerant by introducing the vapor refrigerant which is separated in the vapor liquid separator, and a condenser condensing a refrigerant compressed by the compressor;   an entire cooling mode refrigerant circuit configured to pass through a first expansion device, a first evaporator, and a second evaporator;   a freezing mode refrigerant circuit configured to pass through the second expansion device and the second evaporator to bypass the first expansion device and the first evaporator;   a flow path switching device configured to switch a flow path to allow a liquid refrigerant introduced from the vapor liquid separator to flow through at least one of the entire cooling mode refrigerant circuit and the freezing mode refrigerant circuit; and   an ejector configured to mix a refrigerant, which is discharged from the condenser in the main refrigerant circuit, and a refrigerant, which is discharged from the second evaporator in at least one of the entire cooling mode refrigerant circuit and the freezing mode refrigerant circuit, to introduce to the vapor liquid separator.   
     
     
         17 . The cooling apparatus of  claim 16 , wherein the ejector mixes a refrigerant discharged from the condenser and a refrigerant discharged from the second evaporator, increases a pressure of the mixed refrigerant, and discharges to the vapor liquid separator. 
     
     
         18 . A control method of a cooling apparatus having a first refrigerant circuit configured to allow a refrigerant discharged from a compressor to flow to a suction side of the compressor by passing through a condenser, an ejector, and a vapor liquid separator; a second refrigerant circuit configured to allow the refrigerant to be sucked into an inlet of the ejector to circulate by passing through the ejector, the vapor liquid separator, a first expansion device, a first evaporator cooling a first cooling compartment, and a second evaporator cooling a second cooling compartment; a third refrigerant circuit configured to allow the refrigerant passing through the vapor liquid separator to be sucked into an inlet of the ejector by passing through a second expansion device and the second evaporator to bypass the first expansion device and the first evaporator, and a flow path switching device installed on a portion of a discharge side of the vapor liquid separator to switch a refrigerant flow to allow a liquid refrigerant passing through the vapor liquid separator to pass through at least one of the second refrigerant circuit and the third refrigerant circuit, the control method comprising:
 cooling the first and the second cooling compartments by controlling the flow path switching device so that a refrigerant may flow through the first refrigerant circuit and the second refrigerant circuit; and 
 cooling the second cooling compartment by controlling the flow path switching device so that a refrigerant may flow through the first refrigerant circuit and the third refrigerant circuit when a temperature of the first cooling compartment reaches a target temperature. 
 
     
     
         19 . The control method of  claim 18 , wherein the amount of a refrigerant flow in the entire cooling mode and the freezing mode is adjusted by controlling the number of rotation of the compressor when an operation through the first refrigerant circuit and the second refrigerant circuit is referred to as an entire cooling mode, and an operation through the first refrigerant circuit and the third refrigerant circuit is referred to as a freezing mode. 
     
     
         20 . The control method of  claim 18 , wherein the first evaporator is defrosted by supplying the compressed refrigerant discharged from the compressor to the second refrigerant circuit by closing the third refrigerant circuit and opening the second refrigerant circuit by controlling the flow path switching device when driving the compressor is stopped.