Development of advanced low-temperature heat transfer fluids for district heating and cooling

Technical Report · Mon Sep 30 00:00:00 EDT 1991

DOI:https://doi.org/10.2172/6619327· OSTI ID:6619327

The feasibility of adding phase change materials (PCMs) and surfactants to the heat transfer fluids in district cooling systems was investigated. It increases the thermal capacity of the heat transfer fluid and therefore decreases the volume that needs to be pumped. It also increases the heat transfer rate, resulting in smaller heat exchangers. The thermal behavior of two potential PCMs, hexadecane and tetradecane paraffin wax, was experimentally evaluated. The heat of fusion of these materials is approximately 60% of that of ice. They exhibit no supercooling and are stable under repeated thermal cycling. While test results for laboratory grade materials showed good agreement with data in the literature, both melting point and heat of fusion for commercial grade hexadecane were found to be considerably lower than literaturevalues. PCM/water mixtures were tested in a laboratory-scale test loop to determine heat transfer and flow resistance properties. When using PCMs in district cooling systems, clogging of frozen PCM particles isone of the major problems to be overcome. In the present project it is proposed to minimize or prevent clogging by the addition of an emulsifier. Effects of the emulsifier on the mixture of water and hexadecane(a PCM) were studied. As the amount of the emulsifier was increased, the size of the solid PCM particles became smaller. When the size of the particles was small enough, they did not stick together or stick to the cold surface of a heat exchanger. The amount of emulsifier to produce this condition was determined.

• Research Organization: Drexel Univ., Philadelphia, PA (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG01-90CE26602
• OSTI ID: 6619327
• Report Number(s): DOE/CE/26602-4; ON: DE93013301
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
DISTRICT COOLING
PHASE CHANGE MATERIALS
HEAT EXCHANGERS
HEAT TRANSFER FLUIDS
ALKANES
EMULSIFIERS
PROGRESS REPORT
SURFACTANTS
ADDITIVES
COOLING
DOCUMENT TYPES
FLUIDS
HYDROCARBONS
MATERIALS
ORGANIC COMPOUNDS
320603* - Energy Conservation
Consumption
& Utilization- Municipalities & Community Systems- Public Utilities- (1980-)