ORC Power Generation

Hi all

Reading the following, I really wonder why our decisionmakers do not turn towards ORC power generation technology to solve the imminent crisis.

Just can not believe, that such systems are not viable on any scale - nuclear also does not come cheap.

DE - November/December 2005

UTC Power, a United Technologies Co., has developed the Pure Cycle TM 200 power system utilizing ORC technology. The Pure Cycle system can utilize waste heat, at temperatures greater than 500°F, from a 1-MW electrical power plant to generate 200 kW of electricity. This reduces the demand from the grid by an impressive 20%. Since the system uses waste heat, its fuel is essentially "free." It generates no additional emissions such as NOx, CO2, or particulates.

Using the Pure Cycle system reduces emissions of NOx by over 4 tons per year and a 100% reduction in CO2 compared with a typical fossil fuel–burning electrical plant generating the same kilowatts. It has low life-cycle (maintenance and repair) costs, and a relatively short payback period. Maintenance and repair activities include replacing filters, checking oil, lubing engine parts, and recharging the working fluid; all of which are preformed at a cost of only $0.01 per kilowatt-hour. The system consists of a power module, evaporator (to heat the organic working fluid), condenser, pumps, and controls.

Its power module includes a 19xR turbine within-line generator. Its working fluid consists of 1,800 pounds of HFC. It can be mated with a wide variety of waste-heat sources including reciprocating engines, gas turbines, thermal oxidizers, landfill flares, kilns, and incinerators.

Turbonen, an Italian company, is a European leader in the application of ORC technology to waste heat recovery. Their ORC turbo-generator is a factory pre--assembled modular unit with a capacity of 800 kW. The modules are easy to transport and ready to install. It is built on a single skid-mounted assembly, and contains all the necessary equipment for electrical production (evaporators, condensers, piping, working-fluid reservoirs, feed pumps, turbine, electric generator, control, and switch-gear). Larger systems can be constructed from multiple modules. An optional regenerator is added for higher temperature applications, such as biomass-powered CHP facilities.

Ormat Technologies Inc. of Nevada specializes in recovered energy generation for a variety of industries and applications. Its Ormat Energy Converter (OEC) utilizes a hermetically sealed organic Rankine cycle generating system, which contains only one smoothly rotating part—the shaft driving the turbine's alternator rotor. Defined as a closed-cycle vapor turbogenerator, it is a self-contained power package suitable for tapping into waste heat from remote locations. It will provide 0.2 kW to 6 kW of continuous electrical power with minimal maintenance or repairs. The system has been used worldwide for the recovery of waste heat from power and industrial applications. The Heidelberg Cement AG plant in Germany operates a turnkey Ormat system generating 1.5 MW from a heat recovery system. Operation of the power plant results in a reduction of 7,000 tons of CO2 emissions each year. The Minakami Tsukiyono-Niiharu Sanitary Facility in Japan uses an Ormat system to generate 550 kW of electricity from the burning of refuse-derived fuel. A 1.3-MW Ormat generator is used by the Shijiazhuang Heating and Power Plant in China to create electricity from waste heat recovered from flue gases.

Barber Nichols Inc., (BNI), a Colorado manufacturer of high-performance specialty turbo-machinery, has been designing and building ORC systems since 1970. BNI has built and operated numerous geothermal and solar energy systems utilizing ORC engines. Two of BNI's geothermal plants are located in California. The plants utilize relatively low-temperature geothermal water (240°F) to produce electricity (700 kW and 1.5 MW) that is sold to the local utility. As with most ORC systems, these units operate continuously without the need for a human operator.

DANIEL P.DUFFY, P.E., is an environmental engineer in Cincinnati, OH.

DE - November/December 2005

someone disagree ?