Development Options For Existing Municipal Steam District Heating Systems

Author : James R. Watt
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (14 download)

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Download or read book District Heating and Cooling Systems for Communities Through Power Plant Retrofit and Distribution Network written by James R. Watt and published by . This book was released on 1979 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phase 1 was essentially a sifting process in which promising combinations of plants and service areas were separated from all possible configurations. As contractor and Project Manager for the Toledo Study, Toledo Edison has tried to remain alert to a variety of possible ownership alternatives. At the conclusion of Phase 1 the electric utility is still the most logical owner and operator of the district heating system. The combination of Acme Station and the downtown Toledo area has been identified as a potential successful Demonstration Project. The existing steam system can serve as an excellent base from which various expansion plans can be derived. Replacing the steam system with a coal fired cogeneration source provides an excellent opportunity for scarce fuel savings. Additional savings accrue to those customers who convert from using scarce fuels directly to the new district heating system. The combined savings is the driving force which makes this project economically feasible. To choose the best alternative for further detailed study in Phase 2,two criteria were used to compare the alternative retrofit scheme. Lifecycle savings computed for the 25 -year life of the investment was the primary measure. Second, the sensitivity of life cycle savings to changes in critical input variables was the second indicator. The sensitivity analysis indicates the relative risks associated with each scheme under varying economic conditions. To determine the scope of the district heating systems under consideration an energy market analysis was conducted. Potential customers were identified which would double and nearly triple the existing steam heating load. Concurrently, the engineering consultant scrutinized the plant to determine sources of steam to serve a range of loads. The Demonstration Team then met to determine which service areas were worthy of consideration. Once four retrofit schemes were selected the detailed comparisons could begin. Since the downtown steam system was the basis of the service area, steam was selected as the best distribution medium. After reviewing twenty different retrofit schemes for Acme Station, the engineering consultant recommended the installation of a back pressure turbine as the best method of obtaining cogeneration steam. The new backpressure turbine will operate in parallel with an existing condensing turbine. This concept provides the benefits of cogeneration and still permits maximum electrical production when there is minimal steam load. Using 235 psig as the extraction pressure permits considerable redundancy within Acme Station since there is a 235 psig header served by several boilers. The most challenging part of the distribution system will be the underground crossing of the Maumee River which separates Acme Station from the proposed service area. Considerable effort will be spent during Phase 2to determine the installation details and cost of the river crossing. Engineering costs of other distribution line extensions will be calculated as well to complete the cost estimate for all components of the distribution network. As a result of the economic analysis, Retrofits #1 and#2 were selected for continued study in Phase 2. Implementing Retrofit #2 would double the steam output and displace over 6 million gallons of oil. The life cycle savings and the risk associated with changing economic conditions is less than that determined for Retrofits #3 and #4.viTo proceed into Phase 2 the, Demonstration Team is being expanded to include two important contributors. An engineering firm specializing in the design of in -building systems is being added. Their expertise will help determine retrofit costs and resolve specific technical concerns of the potential customers. A representative of the City of Toledo will be included since financial options including municipal ownership are still under consideration. In any case, the city government is strongly committed to guiding the redevelopment of downtown Toledo which is currently underway. They share our belief that a coal fired district heating system will enhance redevelopment efforts. Community support for the Demonstration Program can be better focused with appropriate involvement by local government. The Task 7 report concludes with the site -specific Scope of Work Toledo Edison developed with the subcontractors to address the requirements of Phases 2 and 3. Because of the nature and size of the Demonstration Project in Toledo, we intend to complete all the technical and economic tasks during Phase 2. Only the final rate making, legal and financing tasks will have to be carried into Phase 3 which we propose to start immediately after the completion of Phase 2. Because of the different costs sharing formulas for Phases 2 and 3, we have created separate technical and cost proposals for the two subsequent phases. Toledo Edison seeks approval, however, for both phases now to accelerate the pace of the Demonstration Program.