JAPAN

A highly efficient heat energy source today for the carbon-free future of tomorrow

Article - March 29, 2023

For over 120 years, Kawasaki Thermal Engineering has been on the boil in providing world firsts when it comes to package boilers and absorption chillers.

WILLHEAT 99%

Kawasaki Thermal Engineering Co., Ltd. (KTE) launched the WILLHEAT series of compact once-through boilers equipped with low-NOx,^*1 hydrogen combustion dry burners, in Japan market.

This product was developed based on KTE's experience and technologies from the manufacturing of boilers that use hydrogen byproduct from petrochemical plants, steelworks, caustic soda production operations and other such facilities and processes as their fuel. Development also took advantage of Kawasaki Heavy Industries' knowledge in hydrogen-related fields. For these latest boilers, KTE developed a new type of burner fueled by hydrogen, which is a highly promising, environmentally friendly, next-generation energy source.

Hydrogen is a clean energy source that emits no CO₂ during combustion, but due to its high burning temperature it produces roughly three times the NOx emissions of natural gas fuel.^*2 KTE's new products use dry burners, which do not require NOx-reduction measures seen in standard-type burner combustion chambers such as steam-spraying systems^*3 and exhaust-gas recirculation.^*4 Furthermore, these products utilize a proprietary hydrogen and air mixing approach to achieve NOx emissions on par with natural gas combustion emissions, even with consideration taken for the low air ratio^*5 stipulated by the Energy Saving Act.^*6 Because no steam spraying is carried out, unnecessary steam output, heat loss, and other operational waste can be avoided. Moreover, no exhaust gas recirculation equipment is required, which reduces costs normally incurred in conventional hydrogen-combustion boilers due to superior maintainability and so forth.

Moving forward, both KTE and the Kawasaki Group will continue revolutionizing technologies for hydrogen-related products used in boilers, absorption chillers and other equipment, while actively expanding hydrogen-related product offerings. At the same time, they aim to respond with precision to a diverse range of market needs and contribute toward environmental load reductions and the achievement of a society with minimal or no carbon emissions.

The following is a basic summary of product features for KTE's new boiler product series.

Low-NOx hydrogen combustion dry burner

Hydrogen-fired Multi tube once-through boiler

Features

(1) Excellent environmental, safety, and energy-saving performance

NOx emissions are kept at 60 ppm or less (at 5% O₂) based on the low air ratio standards^*5 specified in the Energy Saving Act
Rated boiler efficiency of 98% (with steam pressure at 0.49 MPa, feed water temperature at 15°C and supply steam temperature at 35°C)
Continuous inverter control is used for the forced-draft fan and supply water pump to reduce electric power consumption during operation
Original proportional-integral-derivative (PID) control is used to maintain high boiler efficiency during operation

(2) High steam quality

PID continuous control for combustion and feed water mitigates pressure fluctuations caused by transitions between combustion phases and temperature changes in the boiler during water supply operations (±0.005 MPa^*7)
PID continuous control is applied for feed water to control the steam–water separator's water level, which facilitates stable water levels, and this used in conjunction with the separator's rotation function achieve a high level of steam dryness (99.8%^*7)