NineSigma, representing an information and communication technology company, is inviting proposals to develop or adopt compact chillers that can be driven by sun-warmed water of < 70°C. Requirements for compact chillers are: heat source temperature of < 70°C, size of < 1.0 x 1.0 x 1.0 m3, and cooling capacity of > 3 kW.
The heat source temperature requirement is mandatory at the proposal stage, while the others can be more flexible. Proposals for chillers driven by the heat transfer media other than water are also welcomed, if they can evolve to a warm-water driven system.
The company is pursuing research and development into the effective use of exhaust heat arising from solar power generators. A major challenge is that the temperature of the exhaust heat is so low that it is difficult to collect substantial energy as a typical absorbent heat pump requires a heat source of >100°C to regenerate the absorbent.
The company has evaluated various chiller systems that may be effective around their target heat source temperature. However, it has not yet found chiller technology with adequate performance. Therefore, the company has issued a technology request in order to accelerate its technology development and time to market.
Vadim Kavalerov says
You have not specified the cost. If the cost is not an issue, you could use thermo-electric coolers (TEC). There are TEC elements specifically designed to generate electricity from a temperature gradient. A square inch TEC can generate about 10 Watt given 50K differential. Then you could use this current to drive a heat pump (or just a fan, depending on ambient temperature). To move 3 kW, it is probably necessary to have 300 Watt power source. Such device would cost >$10K but appears doable.