Page 59 - Sustainable On-Site CHP Systems Design, Construction, and Operations

38 CHP B a s i c s

• Turbine inlet cooling
• Exhaust systems
• Exhaust heat recovery
• Lube oil systems
• Lube oil heat recovery or rejection
• Engine jacket cooling water
• Water treatment systems
• Heat rejection systems such as cooling towers
• Battery or compressed air starting system
• Black start generator/backup power system
• A method of integration of voltage and phase with other electrical supplies
• Plant and engine controls
Heat recovery systems recover waste energy, not used in the prime mover to pro-
duce power, to serve thermal loads like building heating, process heating, domestic hot
water production, building cooling, or pool heating, for example. In CHP, the most
common application is to provide steam, hot water, and/or chilled water for building
heating and cooling. These CHP plant systems are discussed later in this chapter and in
Chaps. 10 and 11.
Table 3-1 compares and contrasts prime movers in CHP systems. Engineers, facility
operators, and owners with a good understanding of equipment considerations and
how prime movers integrate into the complete CHP system will find themselves having
more productive and efficient conversations on the subject of CHP and how to best
implement CHP in buildings and facilities.

Fuel-to-Power Equipment
As discussed, most fuel-to-power equipment burns fuel in a combustion process that
converts the chemical energy of the fuel into rotational kinetic energy, which can be
transmitted through a shaft to produce electrical power in an electrical generator (fuel
cells are the exception). Fuel-to-power prime mover equipment is usually connected to
an electrical generator. While the great majority of CHP systems use mechanical energy
to drive a generator to produce electricity, other alternatives involving chemical reac-
tions are currently being studied and implemented. Several types of fuel-to-power
equipment exist today that can effectively generate power. When a prime mover and
generator is a factory combined package, the package is often called an engine-generator-
set or “genset.”
As noted, the basic criterion for CHP is that CHP produces both thermal and electrical
energy from a single fuel source. In this respect, CHP differs from the typical electrical
power generation plant today. The other factor, as described in Chap. 1, is that CHP
typically makes more complete use of the energy value of the fuel by beneficially recov-
ering and using heat which would otherwise be wasted.
There are different choices and methods available when developing a CHP system.
One basic configuration of a CHP system is the use of an IC reciprocating engine or
combustion turbine generator with heat recovery equipment capturing exhaust heat