Passively operated spool valve for drain-down freeze protection of thermosyphon water heaters. Final technical report

Technical Report · Fri Apr 30 04:00:00 EDT 1982

DOI:https://doi.org/10.2172/6718813· OSTI ID:6718813

The work done to extend the existing drain-down valve technology to provide passive drain-down freeze protection for thermosyphon-based solar water heaters is described. The basic design of the existing valve model is that of a spool valve, employing a cylindrical spool which moves axially in a mating cartridge to open and close o-rings at the two operating extremes (drain and operate) to perform the valving function. Three passive actuators to drive the basic valving mechanism were designed, fabricated, and tested. Two piping configurations used to integrate the spool valve with the thermosyphon system are described, as are the passive actuators. The three actuator designs are: photovoltaic driven, refrigerant-based bellows, and heat motor cable-drive designs. Costs are compared for the alternative actuator designs, and operating characteristics were examined for the thermosyphon system, including field tests. The market for the valve for thermosyphon systems is then assessed. (LEW)

• Research Organization: Sunspool Corp., Palo Alto, CA (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: FC02-80CS30533
• OSTI ID: 6718813
• Report Number(s): DOE/CS/30533-1; ON: DE83001015
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140907* -- Solar Thermal Utilization-- Water Heating
ACTUATORS
APPLIANCES
BELLOWS
CONTROL EQUIPMENT
DESIGN
DRAIN-DOWN SYSTEMS
EQUIPMENT
EXPANSION
FABRICATION
FIELD TESTS
FLOW REGULATORS
FREEZE PROTECTION
HEATERS
MARKETING RESEARCH
MECHANICAL STRUCTURES
PERFORMANCE TESTING
SOLAR CELL ARRAYS
SOLAR EQUIPMENT
SOLAR WATER HEATERS
TESTING
THERMAL EXPANSION
THERMOSYPHONS
VALVES
WATER HEATERS