Two phase oil cooling system

Abstract

The present disclosure provides a two phase oil cooling system for a work vehicle. The system includes a condenser, an evaporator, a refrigerant path, and a pump. The condenser cools a refrigerant from vapor form to liquid form. The evaporator exchanges heat between a first fluid of the work vehicle and the refrigerant, and heats the refrigerant from liquid form to vapor form. The refrigerant path comprises a first refrigerant path thermally coupling the condenser to the evaporator and a second refrigerant path thermally coupling the evaporator to the condenser. The refrigerant flows through the refrigerant path. The pump is positioned in the first refrigerant path for pumping the refrigerant from the condenser to the evaporator, such that the evaporator is downstream of the pump and the condenser is downstream of the evaporator.

What is claimed is: 
     
         1 . A two phase oil cooling system for a work vehicle, comprising:
 a condenser configured to cool a refrigerant from vapor form to liquid form;   an evaporator configured to exchange heat between a first fluid of the work vehicle and the refrigerant, thereby heating the refrigerant from liquid form to vapor form;   a refrigerant path comprising a first refrigerant path thermally coupling the condenser to the evaporator and a second refrigerant path thermally coupling the evaporator to the condenser, the refrigerant configured to flow through the refrigerant path; and   a pump positioned in the first refrigerant path for pumping the refrigerant from the condenser to the evaporator, such that the evaporator is downstream of the pump and the condenser is downstream of the evaporator.   
     
     
         2 . The two phase oil cooling system for a work vehicle of  claim 1 , wherein the first fluid is an oil of a rotating component of the work vehicle. 
     
     
         3 . The two phase oil cooling system for a work vehicle of  claim 2 , wherein the evaporator is at least partially submerged in the oil within the rotating component of the work vehicle. 
     
     
         4 . The two phase oil cooling system for a work vehicle of  claim 3 , wherein when the rotating component operates, the oil is driven to flow with turbulence over at least one surface of the evaporator to increase heat exchange rate. 
     
     
         5 . The two phase oil cooling system for a work vehicle of  claim 2 , wherein the evaporator is positioned outside the rotating component, and the oil of the rotating component is in fluid communication with the rotating component and the evaporator via a first oil path and a second oil path which couple the rotating component to the evaporator. 
     
     
         6 . The two phase oil cooling system for a work vehicle of  claim 5 , wherein the evaporator comprises a refrigerant passage through which flows the refrigerant and the refrigerant passage thermally couples the first refrigerant path to the second refrigerant path, and an oil passage through which flows the oil and the oil passage thermally couples the first oil path to the second oil path, and the refrigerant passage and the oil passage are at least in proximity to or engaged with one another to exchange heat. 
     
     
         7 . The two phase oil cooling system for a work vehicle of  claim 6 , comprising an oil pump positioned in the first oil path, and the oil pump pumping the oil from the rotating component to the evaporator. 
     
     
         8 . The two phase oil cooling system for a work vehicle of  claim 7 , comprising an oil filter positioned in one of the first oil path and the second oil path to filter the oil of the rotating component. 
     
     
         9 . The two phase oil cooling system for a work vehicle of  claim 1 , wherein the pump is a two-phase flow pump, pumping the refrigerant in liquid and vapor forms. 
     
     
         10 . The two phase oil cooling system for a work vehicle of  claim 1 , comprising a separator positioned in the first refrigerant path between the condenser and the pump and configured to separate the refrigerant in vapor form from the refrigerant in liquid form to permit the refrigerant in liquid form to flow through the pump. 
     
     
         11 . The two phase oil cooling system for a work vehicle of  claim 10 , comprising a reverse refrigerant path coupling the separator to the second refrigerant path, through the reverse refrigerant path flows the refrigerant in vapor form from the separator to the second refrigerant path. 
     
     
         12 . The two phase oil cooling system for a work vehicle of  claim 11 , comprising a reverse flow control valve positioned in the reverse refrigerant path. 
     
     
         13 . The two phase oil cooling system for a work vehicle of  claim 10 , comprising a compressor path coupling the separator to the first refrigerant path, and a compressor positioned in the compressor path, the compressor compressing the refrigerant that is vapor form flowing from the separator through the compressor path to the evaporator, and the pump pumping the refrigerant that is liquid form flowing from the separator through the first refrigerant path to the evaporator. 
     
     
         14 . The two phase oil cooling system for a work vehicle of  claim 13 , comprising an energy recycling unit positioned in the second refrigerant path, the energy recycling unit including a turbine driven by the refrigerant. 
     
     
         15 . The two phase oil cooling system for a work vehicle of  claim 14 , wherein the energy recycling unit comprises one of a secondary pump and a generator coupled to the turbine. 
     
     
         16 . The two phase oil cooling system for a work vehicle of  claim 1 , comprising an energy recycling unit positioned in the second refrigerant path, the energy recycling unit including a turbine driven by the refrigerant, and one of a secondary pump and generator coupled to the turbine. 
     
     
         17 . The two phase oil cooling system for a work vehicle of  claim 2 , comprising a flow control valve positioned in the first refrigerant path between the pump and the evaporator, the flow control valve operating based on a temperature of the oil. 
     
     
         18 . The two phase oil cooling system for a work vehicle of  claim 17 , comprising more than one of the evaporators and more than one rotating components having oils, wherein the first refrigerant path divides a plurality of sub-first refrigerant paths, the second refrigerant path divides a plurality of sub-second refrigerant paths, and each of the evaporators is coupled to one of the sub-first refrigerant paths and to one of the sub-second refrigerant paths and exchanges heat between oil of one of the rotating components and the refrigerant flowing through the evaporator. 
     
     
         19 . The two phase oil cooling system for a work vehicle of  claim 18 , comprising more than one flow control valves, each of which is positioned respective to one of the sub-first refrigerant paths, the flow control valves are configured to control the refrigerant flowing in the sub-first refrigerant paths. 
     
     
         20 . The two phase oil cooling system for a work vehicle of  claim 1 , comprising a condenser fan configured to cool the condenser and a pump-condenser fan control logic coupled to the pump and the condenser, and the pump-condenser fan control logic configured to regulate the condenser to cool the refrigerant before the pump pumping the refrigerant. 
     
     
         21 . The two phase oil cooling system for a work vehicle of  claim 1 , comprising a heat exchanger configured to exchange heat between the first fluid and an oil of a rotating component of the work vehicle. 
     
     
         22 . The two phase oil cooling system for a work vehicle of  claim 21 , wherein the first fluid is an antifreeze, the evaporator is positioned outside the rotating component, the first fluid is in fluid communication with the evaporator and the heat exchanger via an antifreeze path which couples the evaporator to the heat exchanger. 
     
     
         23 . The two phase oiling cooling system for a work vehicle of  claim 22 , further comprising an antifreeze pump positioned in the antifreeze paths and configured to pump the antifreeze to the evaporator. 
     
     
         24 . The two phase oiling cooling system for a work vehicle of  claim 1 , comprising a condenser fan configured to cool the condenser, the condenser fan positioned downstream of the evaporator and upstream of the condenser such that the condenser fan is at least partially driven by a volumetric expansion of the refrigerant. 
     
     
         25 . A two phase oil cooling system for a work vehicle, comprising:
 a condenser configured to cool a refrigerant from vapor form to liquid form;   an evaporator positioned below the condenser and configured to exchange heat between an oil of a rotating component of the work vehicle and the refrigerant, thereby heating the refrigerant from liquid form to vapor form; and   a refrigerant path thermally coupling the condenser to the evaporator, the refrigerant configured to flow in bi-directions in the refrigerant path, driven by difference of densities of the refrigerant responsive to temperatures of the refrigerant within the refrigerant path, within the condenser, and within the evaporator.   
     
     
         26 . A method for cooling a rotating component, comprising:
 pumping a refrigerant at least partial in liquid form to an evaporator and moving the refrigerant at least partial in vapor form to a condenser via the pumping such that a pressure of the refrigerant flowing into the evaporator is higher than another pressure of the refrigerant flowing into the condenser;   absorbing a heat from an oil in the rotating component by the evaporator to evaporate the refrigerant from liquid form to vapor form; and   cooling the refrigerant at least partial in vapor form via the condenser.