CPC F25J 1/0244 (2013.01) [F25J 1/0055 (2013.01); F25J 1/0212 (2013.01); F25J 1/0262 (2013.01); F25J 2290/32 (2013.01)] | 3 Claims |
1. A method for cooling a fluid with a mixed refrigerant including the steps of:
a. separating a high pressure mixed refrigerant stream to form a high pressure vapor stream and a high pressure liquid stream;
b. cooling the high pressure vapor in a heat exchanger, to form a mixed phase cold separator feed stream;
c. separating the mixed phase cold separator feed stream with a cold vapor separator, to form a cold separator vapor stream and a cold separator liquid stream;
d. condensing the cold separator vapor stream and flashing to form a cold temperature refrigerant stream;
e. cooling the cold separator liquid stream to form a subcooled cold separator liquid stream;
f. flashing the subcooled cold separator liquid stream using a cold separator liquid expansion device to form a first mixed phase stream;
g. cooling the high pressure liquid stream in the heat exchanger, to form a subcooled high pressure liquid stream;
h. flashing the subcooled high pressure liquid stream using a high pressure liquid expansion device to form a second mixed phase stream;
i. combining the first and second mixed phase streams to form a middle temperature refrigerant stream;
j. measuring a temperature of a fluid stream exiting the cold vapor separator;
k. comparing the temperature measured in step j. with a set point temperature;
l. Controlling a flow rate through the cold separator liquid expansion device or the high pressure liquid expansion device based on the comparison of step k;
m. determining a liquid level in the cold vapor separator and controlling the cold separator liquid expansion device based on the determined liquid level;
n. combining the middle temperature refrigerant stream and the cold temperature refrigerant stream;
o. warming the combined middle temperature refrigerant stream and cold temperature refrigerant stream in the heat exchanger to form a refrigerant return stream; and
p. thermally contacting a feed fluid in the heat exchanger, to form a cooled feed fluid product stream.
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