OCTOBER 19-20, 2012 - YMCA University of Science & Technology

Proceedings of the National Conference on
Trends and Advances in Mechanical Engineering,
YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012
PERFORMANCE INVESTIGATION OF A COMPACT TRI-GENERATION
SYSTEM BASED ON RENEWABLE ENERGY POWER PLANT EXHAUST GAS
WASTE HEAT UTILIZATION
Dr. Raj Kumar 1 , Anil Kumar 2
1 Professor (Mechanical Engineering Department)
2 Ph.D. scholar, mech_annu@rediffmail.com
1,2 YMCA University of Science & Technology, Faridabad
Abstract
This paper presents a compact tri-generation system in order to cover the electric and thermal power demand of
small rural areas using the renewable energy. The gasifier generator coupled power plants are being widely
used in rural communities where electric network doesn’t exist. The recovery of the exhaust gases makes the
system very attractive. Apart from it, there is the performance study of a compact power plant and a trigeneration
plant. The stack gases from internal combustion engine are directed to a 25 kW ammonia-water
absorption refrigeration chiller. In the power plant,31.25% is the electric power generation of the total fuel gas
input and same amount of stack gases at temperature 400 0 C just at out let of engine is used to operate
absorption chiller machine which is having COP of 0.517. The temperature of cold storage was between 0 0 C-5 C
at 15kW cooling capacity. The engine water jacket was used for heating purpose and the temperature gain was
between 60 0 C -63.5 0 C.
Keywords: Tri-generation, renewable energy, exhaust gas waste.
1. INTRODUCTION
Though producer gas as a fuel has been known since 1785, gasifier use with engines for power
generation came into existence only around 1920. Maximum Gasification development activities were carried
out during the II nd world war due to the shortage of fossil fuels. The possibilities of using this gas for heating and
power generation was first realized by Europe, therefore this gas emerged in Europe producer gas system. With
recent price rise and scarcity of fossil fuel there has been a trend towards use of alternative energy sources like
solar, wind, biomass etc . Biomass derived gaseous fuel can be proved better in running Internal Combustion
Engine to produce electricity for agro enterprises, processing of agricultural products, lighting and other end uses
(Arteconi et al. 2009). But there is huge wastage of heat energy as the stack gas so it may boost to develop new
technologies for efficient use of this type of energy. One such technology is downdraft gasifier integrated with SI
Engine running an electric generator and simultaneously the stack gases from engine can be used in operating the
vapor absorption machine as well as heating (Rathore et al. 2009). The MNRE New Delhi has developed and
installed such system.
2. SYSTEMS DESCRIPTION
2.1 POWER PLANT
The biomass-based power plant installed at MNRE New Delhi is of 50kW rated capacity. The system consists of
a gasifier, water scrubber filters and gas engine coupled with AC Generator. The details of the system are given
in Fig. 1.
(i) Gasifier: The gasifier is of down draft type with vibrator. The ash is removed through it. The gasifier outlet is
connected with ventury water scrubber. In a ventury negative pressure is created through which producer gas is
supplied to burner for starting of gasifier (Sridhar et al. 2001). It is having possible different zones which can be
distinguished four separate zones in the gasifier: Drying zone, Pyrolysis zone, Oxidation (combustion) zone &
Reduction zone (Sridhar et al. 2004).
(ii) Cooling and cleaning system: The gas produced from gasifier is passed through a cooling & cleaning
system consisting of a ventury, one course filter, two fine filters and one security filter. The gas coming out from
the gasifier is cooled in a ventury scrubber. The cooled gases received after ventury scrubber was further cleaned
in the course filter. The coarse filter is filled with small wood chips. In which tar & solid particulates present in
gases gets cleaned. The gases are further passed through two units of fine filters. The fine filters are filled with
sawdust in which the tar is further cleaned and sent to security filter. The security filter is fitted with fabric cloth.
The gases are passed through fabric cloth to arrest the remaining dust particles present in the producer gas. The
cleaned gases are supplied to SI Engine coupled with AC Generator.
17