Hydrodynamic instability of solar thermosyphon water heaters

Journal Article · Tue Feb 01 04:00:00 EST 1994 · Journal of Solar Energy Engineering; (United States)

DOI:https://doi.org/10.1115/1.2930066· OSTI ID:7304871

Du, S C; Huang, B J; Yen, R H ^[1]

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1. National Taiwan Univ., Taipei (Taiwan, Province of China). Dept. of Mechanical Engineering

The flow instability of a solar thermosyphon water heater is studied analytically. A system dynamics model is derived by means of a one-dimensional approach and a linear perturbation method. The characteristic equation is obtained and the Nyquist criterion is used to examine the flow stability. The parameter M is a dimensionless parameter of system stability. The stability maps are plotted in terms of 14 parameters. The occurrence of hydrodynamic instability is determined by comparing the stability curves and the designed values of M. Flow instability is shown not to occur in most of solar water heaters commercially available, because the loop friction is relatively high in the design and because solar irradiation in field operation is still not high enough to cause flow instability.

• OSTI ID: 7304871
• Journal Information: Journal of Solar Energy Engineering; (United States), Journal Name: Journal of Solar Energy Engineering; (United States) Vol. 116:1; ISSN JSEEDO; ISSN 0199-6231
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140907* -- Solar Thermal Utilization-- Water Heating
APPLIANCES
CIRCULATING SYSTEMS
CONVECTION
ENERGY TRANSFER
EQUIPMENT
FLUID FLOW
FLUID MECHANICS
HEAT TRANSFER
HEATERS
HYDRODYNAMICS
LIQUID FLOW
MASS TRANSFER
MECHANICS
PASSIVE SOLAR WATER HEATERS
SOLAR EQUIPMENT
SOLAR WATER HEATERS
THERMOSYPHON EFFECT
WATER HEATERS