Temperature control system

Abstract

A temperature control system, including a closed refrigerant circuit having an evaporator unit for absorbing heat via the refrigerant, thereby evaporating it, a compressor unit with a mechanical compressor for increasing the pressure of the refrigerant and a thermal collector for using an external heat source to increase the temperature of refrigerant within the circuit, and a condenser unit for rejecting heat from the refrigerant, liquefying it.

The invention claimed is: 
     
       1. A temperature control system, the system comprising a closed refrigerant circuit, comprising:
 an evaporator unit configured for absorbing heat via the refrigerant, thereby evaporating it the refrigerant; 
 a compressor unit comprising:
 a mechanical compressor configured for increasing the pressure of the refrigerant within the circuit, and 
 a thermal collector configured for utilizing an external heat source to increase the temperature of the refrigerant within the circuit; and 
 
 a condenser unit configured for rejecting heat from the refrigerant within the circuit, thereby liquefying it the refrigerant, said condenser unit being the first unit downstream the thermal collector that rejects heat from the refrigerant. 
 
     
     
       2. The temperature control system according to  claim 1 , wherein said thermal collector comprises a solar collector configured for capturing heat from incident solar radiation. 
     
     
       3. The temperature control system according to  claim 2 , wherein said solar collector comprises a refrigerant-carrying conduit within an evacuated enclosure, a radiation-facing side of the enclosure comprising a transparent material. 
     
     
       4. The temperature control system according to  claim 3 , wherein said enclosure is evacuated. 
     
     
       5. The temperature control system according to  claim 3 , wherein said solar collector further comprises a heat-sink associated with said refrigerant-carrying conduit, said heat-sink being configured to absorb solar energy and transfer it to said refrigerant-carrying conduit. 
     
     
       6. The temperature control system according to  claim 5 , wherein said heat-sink is formed with projections extending radially from said refrigerant-carrying conduit. 
     
     
       7. The temperature control system according to  claim 5 , wherein said heat-sink is made of an extruded material. 
     
     
       8. The temperature control system according to  claim 5 , wherein said heat-sink is made of a metal. 
     
     
       9. The temperature control system according to  claim 5 , wherein at least radiation-facing surfaces of said heat-sink are designed to lower reflectivity thereof. 
     
     
       10. The temperature control system according to claim  1  18, further comprising:
 temperature sensors disposed to measure the temperature of the refrigerant upon entering and exiting said thermal collector; and 
 athe controller configured to determine an expected temperature increase of the refrigerant in the thermal collector based on the temperature measured by said temperature sensors, and to control operation of said mechanical compressor by causing the variable-frequency drive to vary the speed of the mechanical compressor at least based on said expected temperature increase temperature of the refrigerant measured by the temperature sensors. 
 
     
     
       11. The temperature control system according to  claim 10 , wherein said compressor unit comprises a variable-frequency drive to vary the speed of the mechanical compressor. 
     
     
       12. The temperature control unit according to  claim 1 , configured to operate a vapor-compression refrigeration cycle. 
     
     
       13. The temperature control system according to  claim 1 , further comprising a metering device downstream of said condenser unit configured for regulating flow of liquid refrigerant. 
     
     
       14. The temperature control system according to  claim 1 , being a split-system air conditioning system. 
     
     
       15. The temperature control system according to  claim 1 , further comprising a reversing valve configured to cause said refrigerant to flow in a reverse direction, thereby enabling said evaporator unit to reject heat from the refrigerant, and said condenser unit to absorb heat to the refrigerant. 
     
     
       16. The temperature control system according to  claim 1 , wherein said condenser unit constitutes a portion of a water heating system, water heater being configured to utilize the heat rejected from the refrigerant to heat water. 
     
     
       17. A temperature control system, the system comprising a closed refrigerant circuit comprising:
 an evaporator unit configured for absorbing heat via the refrigerant, thereby evaporating the refrigerant;   a compressor unit comprising:
 a mechanical compressor configured for increasing the pressure of the refrigerant within the circuit, 
 a thermal collector arranged downstream of the mechanical compressor, the thermal collector being configured for utilizing an external heat source to increase the temperature of the refrigerant within the circuit; 
   a condenser unit configured for rejecting heat from the refrigerant within the circuit, thereby liquefying the refrigerant; and   a reversing valve configured to cause said refrigerant to flow in a reverse direction, thereby enabling said evaporator unit to reject heat from the refrigerant and said condenser unit to absorb heat to the refrigerant, wherein the reversing valve is configured to maintain the thermal collector downstream of the mechanical compressor when the refrigerant is caused to flow in said reverse direction.    
     
     
       18. The temperature control system according to claim 1, the temperature control system being configured to meet a cooling load, wherein the mechanical compressor comprises a variable-frequency drive configured to vary speed of the mechanical compressor,
 the closed refrigerant circuit further comprising:   a controller configured to control operation of the mechanical compressor at least by causing the variable-frequency drive to vary the speed of the mechanical compressor,   wherein the system is configured to operate the mechanical compressor at a variable speed based on the cooling load and the temperature of the refrigerant.    
     
     
       19. The temperature control system according to claim 17, the temperature control system being configured to meet a cooling load,
 wherein the mechanical compressor comprises a variable-frequency drive configured to vary speed of the mechanical compressor, and   wherein the system is configured to operate the mechanical compressor at a variable speed based on the cooling load and the temperature of the refrigerant.