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Title: Raft River binary-cycle geothermal pilot power plant final report

Abstract

The design and performance of a 5-MW(e) binary-cycle pilot power plant that used a moderate-temperature hydrothermal resource, with isobutane as a working fluid, are examined. Operating problems experienced and solutions found are discussed and recommendations are made for improvements to future power plant designs. The plant and individual systems are analyzed for design specification versus actual performance figures.

Authors:
;
Publication Date:
Research Org.:
EG and G Idaho, Inc., Idaho Falls (USA)
OSTI Identifier:
6058153
Report Number(s):
EGG-2208
ON: DE83014808
DOE Contract Number:
AC07-76ID01570
Resource Type:
Technical Report
Resource Relation:
Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English
Subject:
15 GEOTHERMAL ENERGY; GEOTHERMAL POWER PLANTS; DESIGN; PERFORMANCE; RAFT RIVER VALLEY; 2-METHYLPROPANE; BINARY-FLUID SYSTEMS; OPERATION; POWER RANGE 1-10 MW; ALKANES; ENERGY SYSTEMS; FEDERAL REGION X; HYDROCARBONS; IDAHO; NORTH AMERICA; ORGANIC COMPOUNDS; POWER PLANTS; THERMAL POWER PLANTS; USA; Geothermal Legacy; 150801* - Geothermal Power Plants- Design & Operation

Citation Formats

Bliem, C.J., and Walrath, L.F.. Raft River binary-cycle geothermal pilot power plant final report. United States: N. p., 1983. Web. doi:10.2172/6058153.
Bliem, C.J., & Walrath, L.F.. Raft River binary-cycle geothermal pilot power plant final report. United States. doi:10.2172/6058153.
Bliem, C.J., and Walrath, L.F.. Fri . "Raft River binary-cycle geothermal pilot power plant final report". United States. doi:10.2172/6058153. https://www.osti.gov/servlets/purl/6058153.
@article{osti_6058153,
title = {Raft River binary-cycle geothermal pilot power plant final report},
author = {Bliem, C.J. and Walrath, L.F.},
abstractNote = {The design and performance of a 5-MW(e) binary-cycle pilot power plant that used a moderate-temperature hydrothermal resource, with isobutane as a working fluid, are examined. Operating problems experienced and solutions found are discussed and recommendations are made for improvements to future power plant designs. The plant and individual systems are analyzed for design specification versus actual performance figures.},
doi = {10.2172/6058153},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Apr 01 00:00:00 EST 1983},
month = {Fri Apr 01 00:00:00 EST 1983}
}

Technical Report:

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  • A preliminary analysis was made of the initial startup data taken between October 20 and November 2, 1981 for the 5 MW(e) Pilot Geothermal Power Plant located at the Raft River Site in southeast Idaho. This plant utilizes a dual-boiling isobutane binary cycle. Two test conditions were selected for analysis: (1) a thermal loop test with 94% of the design geofluid flow, and (2) a test at about three-fourths of the design geofluid flow in which one megawatt was generated from working-fluid flow through the low-pressure stage of the turbine. Component and system energy balances were made, and comparisons betweenmore » experimental results and computer simulations of the plant were conducted. A preliminary analysis of condenser tube wall temperatures was performed. Except for a malfunction in the high pressure turbine throttle valve system, the plant performed generally as predicted, and the testing was judged to be successful.« less
  • Estimates of the steady-state performance of the Raft River 5 MW(e) Pilot Geothermal Power Plant have been made using an existing digital computer simulation which has been updated to reflect the individual performance of the actual components in the plant. The plant output (gross and net) has been obtained as a function of geothermal fluid inlet temperature and flow rate and isobutane preheater bypass (boiler inlet subcooling). The plant performance has been determined for two ambient conditions (summer and winter extremes), and different conditions of heat exchanger fouling. These results along with transient simulations, which will be made in themore » near future, are needed to establish operating procedures and set point, check out control system, determine control gains, and set alarm points. Appendix A contains a brief description of the executive code (TAF), the mathmatical model of the plant, and the input-output requirements to obtain steady-state and transient solutions.« less
  • The action assessed here is the construction and operation of a 5- to 6-MW(e) (gross) geothermal pilot plant in the Raft River Valley of southern Idaho. This project was originally planned as a thermal test loop using a turbine simulator valve. The test loop facility (without the simulator valve) is now under construction. The current environmental assessment addresses the complete system including the addition of a turbine-generator and its associated switching gear in place of the simulator valve. The addition of the turbine-generator will result in a net production of 2.5 to 3.5 MW(e) with a commensurate reduction in wastemore » heat to the cooling tower and will require the upgrading of existing transmission lines for offsite delivery of generated power. Construction of the facility will require disturbance of approximately 20 ha (50 acres) for the facility itself and approximately 22.5 ha (57 acres) for construction of drilling pads and ponds, pipelines, and roads. Existing transmission lines will be upgraded for the utility system interface. Interference with alternate land uses will be minimal. Loss of wildlife habitat will be acceptable, and US Fish and Wildlife Service recommendations for protection of raptor nesting sites, riparian vegetation, and other important habitats will be observed. During construction, noise levels may reach 100 dBA at 15 m (50 ft) from well sites, but wildlife and local residents should not be significantly affected if extended construction is not carried out within 0.5 km (0.3 miles) of residences or sensitive wildlife habitat. Water use during construction will not be large and impacts on competing uses are unlikely.« less
  • A series of Rankine cycle studies for power generation utilizing geothermal fluid as the heat source and isobutane as the working fluid are reported. To find the plant configuration which would most effectively utilize the available energy, a parametric study was performed. The desirability of supercritical, single boiler or double boiler cycles, and the relative boiler temperatures and percentage isobutane flow split between the boilers in the double cycles for geothermal fluid temperatures of 260/sup 0/F to 360/sup 0/F were considered. This study was designed to discover thermodynamic trends which would point to an optimum isobutane cycle for geothermal fluidmore » temperatures in this temperature range. The results of the parametric study were applied to derive a Nominal Design Case for a demonstration plant at Raft River, with a geothermal fluid resource at 290/sup 0/F. In addition, plant variations due to tolerances applied to thermodynamic properties and other key factors are included.« less
  • This report details a plan for developing a fluid supply system for the First 5 MW(e) Pilot Power Plant at Raft River. The pilot plant has been specifically designed to use the medium-temperature geothermal water so common throughout the West. EG and G Idaho, Inc., the Department of Energy Raft River Rural Electric Co-op, the US Geological Survey (USGS) and the State of Idaho have worked together to develop a facility that will use an organic liquid as the working fluid. Four wells have been drilled in the Raft River Valley, about ten miles South of Malta, in southern Idaho.more » The completed well system will consist of seven wells: two conventional injection wells, three production wells, and a standby reserve well of each type. The additional three wells are to be drilled in FY-1978, in order to complete a coordinated test program before the First Pilot Power Plant is ready for operation. The system has been designed to meet the test-loop pilot plant's basic requirement: a 2450 gpm supply of geothermal fluid, at a nominal temperature of 290 F and with salinity of less than 5000 ppm. Injection of cooled geothermal fluid into the Raft River reservoir will also require a network of monitor wells. The Idaho Department of Water Resources (IDWR), USGS, EG and G Idaho, and the Department of Energy will jointly select sites for two 1500-foot and five 500-foot monitoring wells. This plan considers the work required to complete construction of the fluid supply system and obtain a preliminary check of its performance capability; the plan will discuss project management, costs, schedules, drilling, testing, environmental monitoring, and safety.« less