Industrial Biomass Boiler Finned Tube Economizer Painted Anti Corrosion
Condensing Economizer Description
1. Industrial Boilers manufacturer a boiler economizer that are heat exchange devices for heating water.
2. They can make use of the enthalpy in fluid streams that are hot, but not hot enough to be used in a boiler, thereby recovering more useful enthalpy and improving the boiler’s efficiency.
3. They are a device fitted to an Industrial Boiler which saves energy by using the exhaust gases from the boiler to preheat the cold water used to fill it.
Energy Savings Potential
1. The available heat in a boiler’s exhaust gases is dependent upon the hydrogen content of the fuel, the fuel firing rate, the percent of excess oxygen in the flue gases, and the stack gas temperature.
2. Consider a natural gas-fired boiler that produces 100,000 lb/hr of 100-psig saturated steam. At 83% efficiency, the boiler firing rate is about 116 MMBtu/hr. At its full firing rate, the boiler consumes over 4,860 lb of natural gas each hour while exhausting 10,938 lb of high temperature water vapor each hour. The water vapor in the flue gas contains over 10.6 MMBtu/hr of latent heat. As shown in Table 2, the total heat actually available for recovery is strongly dependent upon the stack gas temperature at the condensing economizer outlet.
3. Assume that an indirect contact condensing economizer is retrofitted onto this 100,000 lb/hr steam boiler to heat 50% of the makeup water from 55°F to 200°F and flue gases are cooled to 100°F. At these conditions, 12.75MMBtu/hr of total energy is available in the exhaust, of which 7.55 MMBtu/hr will be recovered to heat makeup water in the condensing economizer. More energy could be recovered if additional heat sinks are available.
Combustion Efficiency @4%Excess O2(%)
Stack Gas Temperature F
78 to 83%
350 to 550
With Feedwater Economizer
84 to 86%
250 to 300
With FW and Condensing Economizer
92 to 95%
75 to 150
Flue Gas Temperature Leaving Condensing Economizer