Verified accurate performance simulation model of direct thermosyphon solar energy water heaters

Journal Article · Tue Nov 01 00:00:00 EST 1988 · J. Sol. Energy Eng.; (United States)

DOI:https://doi.org/10.1115/1.3268269· OSTI ID:6430049

Hobson, P A; Norton, B

A detailed analysis of the heat transfers and fluid flows within direct thermosyphonic solar energy water heaters has been undertaken. The collector energy equations were cast in a two-dimensional form in order that the heat transfer and thermal capacitance effects can be simulated accurately at the small flow rates encountered commonly in these buoyancy-driven systems. The use of an appropriate nonisothermal friction factor correlation when calculating energy losses in the collector's riser pipes, produced predicted flow rates which were corroborated to within 2 percent by the values measured under steady flow conditions. For the laminar flow rates and the store configuration investigated, relaxation of the thermocline was shown to be dominated by axial conduction in the store walls. An indoor test facility, monitored and controlled by a microcomputer, enabled ''real'' operating conditions to be simulated. The predicted responses of the system to identical conditions showed good agreement with the corresponding experimental observations, the predicted heat delivery being within 2.8 percent of that measured.

• Research Organization: AFRC Institute of Engineering Research, Wrest Park, Bedford, MK45 HMS (GB); Solar Energy Technology Centre, School of Mechanical Engineering, Cranfield Institute of Technology, (GB)
• OSTI ID: 6430049
• Journal Information: J. Sol. Energy Eng.; (United States), Vol. 110:4
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
42 ENGINEERING
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
HEAT TRANSFER
CALCULATION METHODS
SOLAR WATER HEATERS
SIMULATORS
COMPUTERIZED SIMULATION
DESIGN
ENERGY LOSSES
FLUID FLOW
LAMINAR FLOW
MICROPROCESSORS
PERFORMANCE
TWO-DIMENSIONAL CALCULATIONS
WALLS
ANALOG SYSTEMS
APPLIANCES
COMPUTERS
ELECTRONIC CIRCUITS
ENERGY TRANSFER
EQUIPMENT
FUNCTIONAL MODELS
HEATERS
LOSSES
MICROELECTRONIC CIRCUITS
SIMULATION
SOLAR EQUIPMENT
WATER HEATERS
140907* - Solar Thermal Utilization- Water Heating
420400 - Engineering- Heat Transfer & Fluid Flow
990230 - Mathematics & Mathematical Models- (1987-1989)