Combined heat and power unit

The modular design of the HyPM fuel cells allows scaling for higher power requirements using a variety of configurations, such as series and parallel systems. Potential applications for the technology include vehicle propulsion, auxiliary power units (APU), stationary applications including backup and standby power units, combined heat and power units and portable power applications for the construction industry and the military. 

Ceres Power has designed and built an integrated, wall-mountable combined heat and power unit (CHP). The integrated CHP Unit is capable of generating electricity and all of the central heating and hot water requirements of a typical home, avoiding the need for a separate boiler. The CHP Unit uses the same natural gas, water and electricity connections as a boiler, and is thus easy to install. 

In Japan, being completely dependant on fossil fuels imports, a long tradition exists in developing stationary and mobile fuel cell applications. Programs funded by the NEDO and METI departments have already resulted in hundreds of small scale micro Combined Heat and Power Units as well as fuel cell vehicles running in road demonstrations [4]. 

Fluidised bed combustors are now common-place for large-scale operations and are extensively used in large electricity generating stations. More recently, smaller scale units have been developed for use by individual industrial concerns and in operating, as combined heat and power units, can give overall thermal efficiencies of up to 80 per cent. 

On Testa farm biogas in used in two Fiat Totem combined heat and power units. The performance of the Totem is reported in table V. 

It should also be noted that the hydrogen and fuel cell technologies are also developed for other than automotive uses. Commercial opportunities for fuel cells are already identified and exploited in early niche markets such as forklifts, in emergency power generator back-up, in portable equipment such as laptops, and in stationary use as combined heat and power units. Synergies between innovative progress in these different fields should advance the technology development for FCEVs. 

Fig. 6.1 Primary energy reduction potential of the Vaillant gas-powered combined heat and power unit ecopower 1.0 in comparison to a centralized coal power and a decentralized natural gas-fired conventional boiler...

SOFC technology, on the other hand, offers interesting options to improve the effectiveness of CHP units. The reasons are many the prospects for high efficiency, low emissions, low noise, scalability, reliabihty, and, finally, potentially low cost. However, the main attractiveness in CHP is the high system efficiency even for small units and at part load operation [14]. Among the most interesting applications are stationary distributed power generation (incl. CHP), small residential combined heat and power units (micro CHP), various transport apphcations (auxiliary power units, APU), and medium-sized portable systems up to 5 kWei-... 

Numerous examples of small fuel cell-based power units produced and used for domestic applications could be cited. Thus, the Vaillant Group, which has production facilities in a number of European countries, has developed a combined heat and power unit (CHP unit) designed for an electric power output of 4.6 kW and a heat output of 11 kW. Such units were installed in several countries (Germany, the Netherlands, Spain, Portugal). The European Commission has supported 30% of the full project costs, estimated at 8.6 billion [Kommu-nalwirtschaft, No. 2, p. 107 (2004)]. 

Figure 7.29 Part of a 100-kW SOFC combined heat and power unit. The fuel cell stack is the central unit The fuel processing system is on the small skid at the front, and the thermal manage-ment/electrical/control system is at the rear. The unit is about 8.5 x 3 x 3 m. (Diagram reproduced by kind pomission of Siemens Westinghouse Powct Corporation.)...

Combined heat and power (CHP). A micro combined heat and power unit can be a direct replacement for a conventional domestic boiler. The combined heat and power unit can use most types of fuel and are therefore described as fuel neutral. This new technology is developing quite quickly. 

The United States obtained about 9 percent of its electricity from combined heat and power (cogeneration) systems as of 1997. Cogeneration is more prevalent in some European nations than in the... 

Ceramic Fuel Cells Limited (CFCL) and E.ON U.K. have agreed to develop a fuel cell combined heat and power (CHP) unit that can be fitted... 

On-site combined heat and power (CHP) which has existed for years, includes turbines, reciprocating engines and steam turbines. Gas turbines in the 500-kW to 250-MW produce electricity and heat using a thermodynamic cycle known as the Brayton cycle. They produce about 40,000-MW of the total CHP in the United States. The electric efficiency for units of less... 

A 250 kilowatt atmospheric system is planned for a Toronto, Ontario, Canada site. The system will be operated by Ontario Power Technologies (formerly Ontario Hydro). The unit will supply 145 kilowatts of heat to the site heating system. Electric efficiency is expected to be about 47% (LHV). Operation of the combined heat and power system is expected in late 2001. 

Power consumers in the acrylonitrile process are the air compressors, as well as the compressors of the refrigeration units for HCN condensation. These can be largely covered by HP steam produced in the reactor in combined heat and power cycles. 

By raising the operating pressure and temperature, the output of equilibrium fuel cells is shown to be reduced. The output includes electrical power from the fuel cell, power from the isen-tropic and isothermal circulators, and power from the Carnot cycle. No artificial credit is given for producing combined heat and power by the popular but erroneous addition of power and heat, which have different units, to produce mythical high efficiencies. The addition of similar units (e.g. power plus power, or heat plus heat) is the valid procedure, in line with Joule s irreversible experiment, from which 1W s 1J. The 3> sign can never mean =. In particular the stirred liquid of the experiment cannot be unstirred. 

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