There is world we wish to show you.

Sky, ocean, water. In order to enrich the lives of people who inhabit this blue planet, IHI has created Blue-i SYSTEM as the embodiment of our greatest technological effort so that it may have the power to “Realize your dreams”.

Blue-i SYSTEM (patented by IHI) carries out smooth load response in the middle combustion range, including both high and low load ranges, thus saving on energy and cost, as well as reducing CO .

For our customers and for the future of our planet. Blue-i SYSTEM is a product we wish to offer to customers who appreciate quality.
Improvement of response to load change
Blue-i SYSTEM through a combination of a proportionally controlled middle combustion range (40% to 80%) and fixed high combustion (100%) and low combustion (20%), achieves both prevention of steam pressure change and smooth response to sudden load change. It performs proportional control in the middle combustion range, and when sudden load change occurs, instantly switches over to either high or low combustion, thus enabling load response.
Effective utilization of the high-efficiency zone
The characteristics of the boiler mean that it has maximum efficiency at intermediate load as opposed to full load. The boiler efficiency in the case of conventional multi-stage combustion ran across a fixed straight line connecting two loads, however with Blue-i SYSTEM, the efficiency at 40 to 80% load shifts as a curve, therefore efficiency is expressed as a mountain- shaped curve. As such, it is possible to effectively use the high efficiency zone.

For example, in the case of 75% fixed load, the conventional multi-stage control boiler would repeat high combustion (100%) and medium combustion (50%), and the average boiler efficiency would be the 75% load value on the straight line connecting the high combustion and medium combustion. With Blue-i SYSTEM, continuous operation at 75% load is possible, and the load value is on a mountain-shaped curve, therefore enabling operation at an even higher efficiency than the average efficiency based on a straight line.
High quality steam across all load ranges
A new water level control system suiting proportional control in the middle combustion range enables high steam dryness to be maintained across all load ranges.
Reduction of steaming-up time
Starting and warming up from a cold stopped state is performed in the middle combustion range (40%), thereby reducing steaming-up time.
High-efficiency through latent heat recovery
Latent heat is recovered in the low load range to improve efficiency even further.
Power-saveing benefits
In the case of conventional multi-stage combustion, the shift to the operating frequency of the fan inverter set for each fixed load was repeated therefore power consumption was the average of the
power at each frequency, moreover braking loss would also occur when there was a reduction in load.


With Blue-i SYSTEM, proportional control is performed at between 40 and 80% of the load range, so the power consumption of the fan accompanying load change is practically a value responding to the operating frequency, and braking loss also becomes minimum, therefore it is possible to reduce power

Middle combustion priority with Multi-boiler control system
Multi-boiler control system enabling efficient load response in the case of multiple once through boiler systems. By combining this system and a boiler equipped with Blue-i SYSTEM, it is possible to create a boiler system with the highest efficiency and lowest power consumption.