Apparatus and method for evaporator defrosting

Patent · Sun Dec 31 23:00:00 EST 2000

OSTI ID:873803

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

---

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: LOCKHEED MARTIN ENERGY RES COR
• 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

/62/
accumulating
accumulator
activate
alternately
apparatus
bypass
bypasses
capability
causing
compressing
compressor
condenser
connected
control
cooling
current
cycle
deactivate
defrost
defrosting
depending
device
directing
embodied
enhanced
evaporator
expanding
expands
expansion
expansion device
flow
form
gaseous
gaseous refrigerant
inventive
inventive method
liquid
liquid form
method
passed
passes
passing
pumped
receiver
refrigerant
refrigeration
respectively
selectively
selectively activate
selectively direct
selectively directing
steps
substantially
warm
warm-liquid