Panasonic Corporation, Osaka Gas Co., Ltd., and Daigas Energy Co., Ltd. have developed the industry's first absorption chiller-heater compatible with mixed combustion of hydrogen and city gas.
The multi-fuel compatible unit allows for a mixed combustion ratio of 0% to 100%, and existing city gas-fuelled units can be upgraded to hydrogen-compatible units simply by replacing parts.
The three companies will continue to conduct verification tests with plans to commercialise the unit.
The absorption chiller-heater uses water as a refrigerant.
Moreover, it primarily uses gas and waste heat as its energy source, which is useful for leveling power loads and strengthening resilience in the event of power outages or disasters.
The Daigas Group has been selling absorption chillers and heaters to office buildings and other facilities since 1970.
Daigas Energy has also developed and sold numerous city gas burners for commercial equipment and industrial furnaces, accumulating knowledge in combustion technology and air ratio control technology for burning fuel efficiently and safely.
In recent years, the company has also been working on developing combustion technology that can also be used with next-generation fuels such as hydrogen and ammonia.
Hydrogen, which does not emit CO2 during combustion , has recently been attracting attention as a "clean energy" source.
However, hydrogen has characteristics such as a faster combustion rate and a higher flame temperature than city gas, generating large amounts of NOx (nitrogen oxides) during combustion.
The absorption chiller-heater jointly developed by the three companies enables operation at a hydrogen/city gas mix ratio of 0% to 100% by developing technology that optimally controls the combustion air flow rate based on the hydrogen/city gas mix ratio and air conditioning load.
Furthermore, by incorporating a burner that reduces the flame temperature during hydrogen combustion, NOx levels in the exhaust gas are suppressed to less than 40 ppm.
Existing city gas-fuelled units can be retrofitted to hydrogen-compatible units by simply replacing a few parts, such as the burner and fuel piping.
This allows for a rapid response for customer without the need to replace the entire absorption chiller-heater unit .
The newly developed absorption chiller-heater is an industry first, capable of operating on a combination of hydrogen and city gas, in addition to being able to operate on either hydrogen or city gas.
Previously, due to the differences in combustion characteristics of each fuel, a dedicated burner and combustion air flow rate adjustment was required for each fuel, but these issues have been resolved with the newly developed "hydrogen/city gas dual-use burner" and "combustion control unit."