Direct and indirect heat transfer in water network systems

• Published in: Applied thermal engineering 2002-06, Vol.22 (8), p.981-988
• Main Authors: Savulescu, L.E., Sorin, M., Smith, R.
• Format: Article
• Language: English
• Subjects: Applied sciences; Building technical equipments; Buildings; Buildings. Public works; Direct and indirect heat transfer; Distribution. Storage; Energy management and energy conservation in building; Environmental engineering; Exact sciences and technology; Heat exchangers; Heat recovery; Thermal effects; Thermodynamics; Waste heat utilization; Water networks; Water supply. Pipings. Water treatment
• ISSN: 1359-4311
• DOI: 10.1016/S1359-4311(02)00015-7

This paper addresses direct/indirect heat recovery network design for water network systems. A particular water network case of two different temperature fresh water sources is analysed. A new systematic heat recovery design approach based on thermodynamics is proposed for water stream sets leading to energy pinch problems. The concept of direct/indirect heat transfer decomposition is introduced to explore the design of heat exchanger network (indirect heat transfer) and non-isothermal mixing. This concept is illustrated through a new graphical segregation of the composite curves. To overcome the limitations associated with the representation of stream mixing in the composite curves, a new tool, source–demand energy composite curves, is introduced to evaluate the complexity of direct heat recovery and design different mixing scenarios.