KIMM develops new chemisorption heat pump for low-grade waste heat

South Korea – The Korea Institute of Machinery and Materials (KIMM) has developed a chemical adsorption heat pump that can use waste heat at around 40°C to drive cooling, with a 10 kW-class prototype now undergoing demonstration testing.

Developed with researchers at Chung-Ang University, the system is intended to recover low-grade heat from sources including factories and data centres that would otherwise be difficult to use for conventional adsorption cooling. KIMM says existing adsorption cooling technologies typically require heat sources above 70°C.

Lower-temperature waste heat

KIMM developed the chemisorption heat pump and redesigned its adsorption bed to improve heat and mass transfer within the system.

The researchers reported a specific cooling power of 346.5 W/kg from the adsorption bed, which KIMM says is more than twice the level of comparable overseas technology.

Earlier work under the same research programme included experimental testing of a 500 W chemisorption heat pump designed to operate using a 40°C heat source, helping establish the technical basis for the larger system now being demonstrated.

The most significant achievement of this research is the successful demonstration of cooling using low-temperature waste heat at just 40°C

Young Kim, principal researcher, KIMM Heat Pump Research Centre

Electrochemical compressor

Chung-Ang University developed an electrochemical compressor for the system, replacing a conventional mechanically driven compressor.

The system uses ammonia as the refrigerant, with an electrochemical compressor creating the required pressure lift without conventional mechanical moving parts. The research team highlights reduced energy consumption, noise and vibration compared with conventional mechanical compression.

KIMM said this could make the technology suitable for applications including buildings, hospitals and schools, as well as industrial sites where low-temperature waste heat is available.

Samjung Tech manufactured the 10 kW-class chemisorption heat pump prototype used for the current demonstration programme.

Demonstration underway

KIMM said testing of the prototype is continuing, with future applications being considered for data centres, buildings and industrial facilities.

The research was supported through the Korea Institute of Energy Technology Evaluation and Planning’s Alchemist programme.