Ice thermal storage

A system for providing thermal energy storage in the form of ice to cool heat producing equipment, the system comprising:

• a tank configured to hold water;
• a first heat exchanger disposed in the tank;
• a system housing configured to be rack-mountable inside an information technology equipment rack;
• and
• cooling means for transferring heat out of water in the tank to generate ice, and is configured to convey a two-phase liquid and vapor refrigerant through the first heat exchanger to transfer heat between the water and the refrigerant, the cooling means comprises
• 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 connected to the heat exchanger and 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 valve,
• wherein the tank and cooling means are disposed inside the system housing.