Improve Efficiency Save Energy Gas Hot Water Boiler Economizer Industrial

Improve Efficiency Save Energy Gas Hot Water Boiler Economizer Industrial Applications

What is a boiler economizer?

It's a heat exchanger that preheats feedwater using waste flue gas heat to improve boiler efficiency.

Economizer Description

1, absorb the heat of low temperature flue gas, reduce the exhaust temperature, reduce the exhaust loss, save fuel.

2. Because the water supply is heated in the economizer before entering the drum, the heat absorption of the water supply in the heating surface is reduced. The economizer can be used to replace part of the higher cost of the evaporation heating surface.

Inside the economizer

3. When the temperature of the water supply is increased, the wall temperature difference will be reduced and the thermal stress will be reduced accordingly to extend the service life of the drum.

Classifications

There are two versions of the device used in data centers: air-side economizers and water-side economizers.

• Airside economizers pull cooler outside air directly into a facility to prevent overheating.
• Water-side economizers use cold air to cool an exterior water tower. The chilled water from the tower is then used in the air conditioners inside the data center instead of mechanically-chilled water, reducing energy costs. Water-side economizers often operate during nightime to take advantage of cooler ambient temperatures.

Differences

• A conventional feedwater economizer reduces steam boiler fuel requirements by transferring heat from the flue gas to the boiler feedwater. For natural gas-fired boilers, the lowest temperature to which flue gas can be cooled is about 250°F to prevent condensation and possible stack or stack liner corrosion.
• The condensing economizer improves waste heat recovery by cooling the flue gas below its dew point, which is about 135°F for products of combustion of natural gas. The economizer reclaims both sensible heat from the flue gas and latent heat by condensing flue gas water vapor. All hydrocarbon fuels release significant quantities of water vapor as a combustion byproduct.

Suggested Actions

• Determine your boiler capacity, average steam production, combustion efficiency, stack gas temperature, annual hours of operation, and annual fuel consumption.

• Identify in-plant uses for heated water, such as boiler make-up water heating, preheating, domestic hot water, or process water heating requirements.

• Determine the thermal requirements that can be met through installation of a condensing economizer. Determine annual fuel energy and cost savings.

• Determine the cost-effectiveness of a condensing economizer. Ensure that system changes are evaluated and modifications are included in the design (e.g., mist eliminator, additional water treatment, heat exchangers). Simple paybacks for condensing economizer projects are often less than two years.

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