Apparatus and method for evaporator defrosting

Patent · Mon Jan 01 00:00:00 EST 2001

OSTI ID:873803

Mei, Viung C ^[1]; Chen, Fang C ^[2]; Domitrovic, Ronald E ^[2]

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1. Oak Ridge, TN
2. Knoxville, TN

An apparatus and method for warm-liquid defrosting of the evaporator of a refrigeration system. The apparatus includes a first refrigerant expansion device that selectively expands refrigerant for cooling the evaporator, a second refrigerant expansion device that selectively expands the refrigerant after the refrigerant has passed through the evaporator, and a defrosting control for the first refrigerant expansion device and second refrigerant expansion device to selectively defrost the evaporator by causing warm refrigerant to flow through the evaporator. The apparatus is alternately embodied with a first refrigerant bypass and/or a second refrigerant bypass for selectively directing refrigerant to respectively bypass the first refrigerant expansion device and the second refrigerant expansion device, and with the defrosting control connected to the first refrigerant bypass and/or the second refrigerant bypass to selectively activate and deactivate the bypasses depending upon the current cycle of the refrigeration system. The apparatus alternately includes an accumulator for accumulating liquid and/or gaseous refrigerant that is then pumped either to a refrigerant receiver or the first refrigerant expansion device for enhanced evaporator defrosting capability. The inventive method of defrosting an evaporator in a refrigeration system includes the steps of compressing refrigerant in a compressor and cooling the refrigerant in the condenser such that the refrigerant is substantially in liquid form, passing the refrigerant substantially in liquid form through the evaporator, and expanding the refrigerant with a refrigerant expansion device after the refrigerant substantially passes through the evaporator.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: AC05-96OR22464
• Assignee: Lockheed Martin Energy Research Corp. Oak Ridge National Laboratory (Oak Ridge, TN)
• Patent Number(s): US 6250090
• OSTI ID: 873803
• Country of Publication: United States
• Language: English

Related Subjects

apparatus
method
evaporator
defrosting
warm-liquid
refrigeration
refrigerant
expansion
device
selectively
expands
cooling
passed
control
defrost
causing
warm
flow
alternately
embodied
bypass
directing
respectively
connected
activate
deactivate
bypasses
depending
current
cycle
accumulator
accumulating
liquid
gaseous
pumped
receiver
enhanced
capability
inventive
steps
compressing
compressor
condenser
substantially
form
passing
expanding
passes
expansion device
liquid form
inventive method
gaseous refrigerant
selectively directing
selectively activate
selectively direct
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