Reuse of heat energy in wastewater : implementation examples in Japan

• Published in: Water Science & Technology Vol. 43; no. 10; pp. 277 - 285
• Main Authors: FUNAMIZU, N, IIDA, M, SAKAKURA, Y, TAKAKUWA, T
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Oxford Pergamon Press 01.01.2001; IWA Publishing
• Subjects: Air Conditioning - economics; Air Conditioning - instrumentation; Applied sciences; Capacity; Conservation of Energy Resources - economics; Conservation of Energy Resources - methods; Corrosion; District heating and refrigerating; Energy; Energy Transfer; Energy. Thermal use of fuels; Exact sciences and technology; Heat exchangers; Heat pumps; Heat transfer; Heating; Heating - economics; Heating - instrumentation; Heating, air conditioning and ventilation; Hot Temperature; Japan; Japan, Sapporo; Japan, Tokyo; Melting; Rain; Rain water; Sewage; Sewer systems; Sewerage; Snow; Space heating. Hot water; Specific heat; Treated water; Urban areas; Waste heat recovery; Waste Management - economics; Waste Management - instrumentation; Waste Management - methods; Waste treatment; Wastewater; Wastewater reuse; Wastewater treatment; Asia; Japan; Air conditioning; Snow clearance; Heat pump; Snow melt; District heating refrigeration plant; Heat recovery; Sewage treatment plant; Waste water
• ISBN: 1900222728; 9781900222723
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2001.0640

Sewage and treated water can be a heat source in urban area due to large heat capacity, thus recovery and reuse of its energy is one of the most desirable plans for the sewerage system. In this paper, characteristics of heat energy in wastewater, reuse plans, and some experiences in Japan are presented. Full-scale reuse projects for heating and cooling in the Tokyo Metropolitan Districts and project for melting snow in Sapporo City are discussed. The key factors found in experience of Tokyo were setting the heat pumps near the demand points and the technical developments of equipment to prevent system from clogging, corrosion, and decrease in the heat transfer efficiency. It was also found through the project for melting snow in Sapporo that the key factor in public acceptance was the multi-purpose use of the sewerage system both for melting snow in winter and retaining rain water in summer.