Salient features and operating experience with world`s first rice straw fired fluidized bed boiler in a 10 MW power plant

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:245050

Muthukrishnan, M; Sundararajan, S; Viswanathan, G; Rajaram, S; Kamalanathan, N; Ramakrishnan, P ^[1]

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1. Bharat Heavy Electricals Ltd., Tiruchirapalli (India)

India has a vast resource of biomass, a renewable source of fuel, which if used effectively would reduce the rate of depletion of fossil energy resources. Rice straw is one such biomass which is available abundantly in the state of Punjab in India. Bharat Heavy Electricals Ltd (BHEL), Tiruchirapalli established the Fluidized Bed Combustion of rice straw in their test facilities and engineered a 10 MW rice straw fired power plant. The plant has been installed in the state of Punjab. This is the world`s first power plant using 100% rice straw as fuel in baled form in a fluidized bed. The plant is in successful operation now after overcoming the start-up problems. The steam generator is a bi-drum, bottom supported, bubbling fluidized bed unit, with a pendant superheater and boiler bank. In-bed surfaces have been provided to limit the temperature of the fluidized bed well below that of the straw ash softening temperature. Rice straw bales weighing 15--20 kg are fed through unique overbed feeding system. The bed is segmented in the wind box below the air distributor to enable part load operation. The system generator is provided with heat recovery surfaces like economizer and air heater in the convection pass. An electrostatic precipitator limits the dust emission to the stack. During shakedown trials, it was noticed that combustion of straw was extending up to the freeboard exit. This caused temperature peaks and ash agglomeration on superheater tubes. The straw ash is not free flowing in the convection pass hoppers due to its fluffiness, hence accumulates, sinters making ash evacuation difficult. These problems have been resolved by adopting an improved overfire air arrangement and by use of additives. The salient features and operational experience are elaborated in this paper.

• OSTI ID: 245050
• Report Number(s): CONF-950522--; ISBN 0-7918-1305-3
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
20 FOSSIL-FUELED POWER PLANTS
CALORIFIC VALUE
CHEMICAL COMPOSITION
DESIGN
FLUIDIZED BED BOILERS
FLUIDIZED-BED COMBUSTION
FUEL FEEDING SYSTEMS
HEAT RECOVERY EQUIPMENT
MODIFICATIONS
PERFORMANCE
REFUSE-FUELED POWER PLANTS
STRAW