Patent ID: 7681410

Claim:
A system for use in an information technology equipment rack housing and for use with a pumped refrigerant cooling system that includes vapor and liquid refrigerant lines, the system comprising: a tank configured to hold water; a heat exchanger disposed in the tank and configured to convey a two-phase liquid and vapor refrigerant and to transfer heat between water in the tank and the refrigerant; a first valve comprising first and second ports and being connected to the liquid and vapor refrigerant lines and configured to selectively connect the liquid refrigerant line to the first port and the vapor refrigerant line to the second port in a first mode and to connect the liquid refrigerant line to the second port and the vapor refrigerant line to the first port in a second mode; a second valve directly connected to the first port of the first valve and to an inlet of the heat exchanger, the second valve being a thermostatic expansion valve and configured to operate to deliver liquid refrigerant to the heat exchanger when the first valve is in the first mode; a third valve directly connected to the first port of the first valve and to the inlet of the heat exchanger and configured to direct vapor refrigerant from the first port of the first valve to the inlet of the heat exchanger independent of the second valve and configured to operate to deliver vapor refrigerant to the heat exchanger by bypassing the second valve when the first valve is in the second mode; and a liquid/vapor pump directly connected to an outlet of the heat exchanger and to the second port of the first valve, the liquid/vapor pump being configured to pump refrigerant in only one direction from the heat exchanger to the first valve.