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AssigneeCarrier Corporation
InventorsPaul Valentine Weyna, Richard Alan Simone, Russell George Lewis
Estimating the term…
A method and system for executing a hot gas heating cycle in a mobile refrigeration unit includes diverting a flow of hot gas by bypassing a condenser into a receiver and restricting the flow, thereby raising a discharge pressure and temperature of the unit. The discharge pressure of the unit is monitored, and the restriction is regulated when the discharge pressure reaches a predetermined pressure. A combination of small and large orifice hot gas valves is used, or optionally a hot gas stepper valve. A solenoid valve or an evaporator expansion valve is optionally used to meter refrigerant into the heat loop.
A method for executing a hot gas heating cycle in a mobile refrigeration unit, comprising the steps of:
A method for executing a hot gas heating cycle in a mobile refrigeration unit, comprising the steps of:
A method for executing a hot gas heating cycle in a mobile refrigeration unit, comprising the steps of:
A system for executing a hot gas heating cycle in a mobile refrigeration unit, comprising:
A system for executing a hot gas heating cycle in a mobile refrigeration unit, comprising:
A system for executing a hot gas heating cycle in a mobile refrigeration unit, comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Defrosting cycles: hot gas defrosting
Subcoolers, desuperheaters or superheaters: subcoolers
Component parts or details not otherwise provided for in this subclass: economisers
Component parts or details not otherwise provided for in this subclass: receivers
Term ended 24 Jan 2022 (estimated)
This invention relates generally to the field of mobile refrigeration systems, and more particularly to a mobile refrigeration system with a hot gas heating cycle.
The known heat and defrost algorithms which control mobile refrigeration units use solenoid operated valves to control the hot gas flow. Slow heating to the setpoint as well as long defrost times are common using the prior art algorithms. At low ambient temperatures, trailer refrigeration units with hot gas heating heat very slowly, which leads to inefficiencies.
Briefly stated, a method and system for executing a hot gas heating cycle in a mobile refrigeration unit includes diverting a flow of hot gas by bypassing a condenser into a receiver and restricting the flow, thereby raising a discharge pressure and temperature of the unit. The discharge pressure of the unit is monitored, and the restriction is regulated when the discharge pressure reaches a predetermined pressure. A combination of small and large orifice hot gas valves is used, or optionally a hot gas stepper valve. A solenoid valve or an evaporator expansion valve is optionally used to meter refrigerant into the heat loop.
FIG. 1 shows a system schematic of an embodiment of a mobile refrigeration unit.
FIG. 2 shows a system schematic of an embodiment of a mobile refrigeration unit.
FIG. 3 shows a flow chart used in conjunction with FIG. 2 in explaining an embodiment of the invention.
Referring to FIG. 1, a system schematic of a mobile refrigeration unit 12 is shown. Mobile units use the same conventional refrigeration cycle as other units, but with modifications that provide greater cooling capacity with a smaller physical structure than is generally obtained in stationary units. The following abbreviations are used in the figures.
DPR discharge pressure regulator SV solenoid valve ECXV economizer expansion valve HX heat exchanger UNL unloader CDP compressor discharge pressure HP high pressure switch CDT compressor discharge temperature CST compressor suction temperature CSP compressor suction pressure CECT compressor economizer temperature CECP compressor economizer pressure ESMV electronic suction modulation valve LSHX liquid to suction heat exchanger EVOT evaporator outlet temperature EVOP evaporator outlet pressure EVXV evaporator expansion valve ENRPM engine RPM ENOLS engine oil level switch HGSV hot gas stepper valve
The various sensors and valves in unit 12 are connected to a microprocessor 10. The improvements sought in the present invention are decreased defrost time, decreased heating time to setpoint, and increased system reliability. Unit 12 heats via a hot gas de-superheating cycle.