Intermediate Temperature Cooling Unit

Navy ships have a chilled water system that runs throughout the ship providing cooling to electronic equipment. Operating at a nominal temperature of 42°F, the chilled water system creates a sizable load on the ship’s electrical plant. The DDG 51 class is approaching available power and cooling capacity limits. Reducing the energy required to provide equivalent cooling capacity would preserve Service Life Allowance (SLA) for future system upgrades. Additionally, having cold water running through pipes throughout the ship creates a risk of water condensing on the piping, which can create electrical hazards inside equipment. While some pieces of equipment are designed to receive chilled water at a specific temperature, other pieces of equipment are more flexible in their cooling requirements. These systems could utilize chilled water that is at a higher temperature, which would require less energy to cool and generate less condensation. Estimates indicate that approximately 200 refrigeration tons (rtons) of cooling could be accomplished by an intermediate temperature cooling loop. This load could be supported by one or more intermediate temperature cooling units. There are no Navy-qualified chillers designed to operate at an intermediate temperature. Work is required to design and qualify a new unit that operates at approximately 65°F, with emphasis on a small footprint. The unit shall include the chiller, circulating pump, piping, instrumentation, and controls. A new unit must meet all applicable Navy standards including shock, noise, vibration, and electromagnetic interference (EMI), as well as reliability and maintainability metrics. Cooling mediums may include but are not limited to water, seawater, or water with glycol additives. For commonality purposes, the equipment shall be galvanically compatible with copper-nickel piping. The proposer shall define performance metrics of the proposed solution to include cooling capacity, energy efficiency, power draw, output pressure, output flow rate, and notional Not-To-Exceed physical dimensions for all equipment.