Experimental studies on heat transfer and friction factor characteristics of forced circulation solar water heater system fitted with helical twisted tapes

Jaisankar, S.; Radhakrishnan, T. K.; Sheeba, K. N.

doi:10.1016/j.solener.2009.07.006

Cited by 118 publications

(39 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The high heating performance of the heater was attributed to the roughness and darkness of the pot surface. The copper coil, covering the pot, also contributed to the maximum energy conversion during the heating process [9,10]. The reflected part of the radiative energy was trapped in the copper carrying the water.…”

Section: Resultsmentioning

confidence: 99%

“…The airtight box with glass cover also minimized the heat and radiative losses from the wooden box. The operating characteristics of the thermosyphon solar water heaters can also have significant impact on the efficiency of the system, because the performance of the system was based on the flowrate from the collector, absorber plate temperature and temperature rise of the water from inlet to outlet [9]. Ho and Chen [11] revealed that the sheet and tube based solar water heating is a convenient way of heating the water for domestic use.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Heating Performance Study on a Passive Solar Heater

et al. 2017

View full text Add to dashboard Cite

Abstract.A passive thermosyphon heating system was designed, fabricated and tested for its thermal performance in semi-arid and four-season climate of Pakistan. The heating system design was based on a two-stage storage and natural thermosyphon circulation of the water. The objective of the study was to enhance the heating performance of the thermosyphon systems by using a semicircular steel pot collector, water carrying copper coil cover, two step water storage, and side mirror reflectors. The experiments were conducted during April to July 2014 when ambient temperature was reported to vary between 32ºC and 44ºC. In continuous flow mode operation, the hot water temperature remained between 46ºC and 78ºC. Since water temperature in the range of 45ºC to 50ºC is considered suitable for the domestic use, the presented design can easily reach the temperatures even higher than those acceptable for the domestic use.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Heating Performance Study on a Passive Solar Heater

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Sometimes, water is flown in perpendicular direction through a larger diameter tube where it comes in contact with many small diameter pipes containing heat transfer fluid being heated in the solar heater and indirect heat transfer takes place. This way, periodic operation and maintenance of tube containing harder water becomes easy [34,35,36].…”

Section: Low Temperature Collectormentioning

confidence: 99%

Recent Developments in Heat Transfer Fluids Used for Solar Thermal Energy Applications

Srivastva¹,

Malhotra²,

Sc³

2015

J Fundam Renewable Energy Appl

View full text Add to dashboard Cite

Solar thermal collectors are emerging as a prime mode of harnessing the solar radiations for generation of alternate energy. Heat transfer fluids (HTFs) are employed for transferring and utilizing the solar heat collected via solar thermal energy collectors. Solar thermal collectors are commonly categorized into low temperature collectors, medium temperature collectors and high temperature collectors. Low temperature solar collectors use phase changing refrigerants and water as heat transfer fluids. Degrading water quality in certain geographic locations and high freezing point is hampering its suitability and hence use of water-glycol mixtures as well as water-based nano fluids are gaining momentum in low temperature solar collector applications. Hydrocarbons like propane, pentane and butane are also used as refrigerants in many cases. HTFs used in medium temperature solar collectors include water, waterglycol mixtures -the emerging "green glycol" i.e., trimethylene glycol and also a whole range of naturally occurring hydrocarbon oils in various compositions such as aromatic oils, naphthenic oils and paraffinic oils in their increasing order of operating temperatures. In some cases, semi-synthetic heat transfer oils have also been reported to be used. HTFs for high temperature solar collectors are a high priority area and extensive investigations and developments are occurring globally. In this category, wide range of molecules starting from water in direct steam generation, air, synthetic hydrocarbon oils, nanofluid compositions, molten salts, molten metals, dense suspension of solid silicon carbide particles etc., are being explored and employed. Among these, synthetic hydrocarbon oils are used as a fluid of choice in majority of high temperature solar collector applications while other HTFs are being used with varying degree of experimental maturity and commercial viability -for maximizing their benefits and minimizing their disadvantages. Present paper reviews the recent developments taking place in the area of heat transfer fluids for harnessing solar thermal energy. Refrigerants/phase changing materials: These are low boiling point but high heat capacity substances used in the solar collectors to transfer heat in applications like solar space cooling and heating, refrigerators, air conditioning, etc [7]. These materials absorb heat from the solar collectors, produce work either by expanding in a turbo-generator of a vapor compression cycle or by dissociating the refrigerant from its absorbent in a vapor absorption cycle [8]. In some of the relatively high temperature applications, higher boiling point refrigerants are used as indirect heat transfer fluids, wherein the heat collected from the solar collectors is transferred to another fluid like water from where the refrigerants pick-up heat to do the required work in the turbo-generators [9,10]. Recent Developments in Heat Transfer

show abstract

“…Many research works on the effect of swirl generator for convective heat transfer enhancements in tubes are available in the literature. Jaisankar et al [1] experimentally investigated the thermal characteristics of solar water heater with twisted tape inserts of twist ratios 3,4,5 and 6 for the range ofReynolds number, 3000<Re<23,000. They have reported the maximum increase in convective heat transfer coefficient and friction factor with twisted tape of twist ratio 3.…”

Section: Introductionmentioning

confidence: 99%

Comparative Performance Analysis of Different Twisted Tape Inserts in the Absorber Tube of Parabolic Trough Collector

Rawani¹

2018

IJMPERD

View full text Add to dashboard Cite

Experimental studies on heat transfer and friction factor characteristics of forced circulation solar water heater system fitted with helical twisted tapes

Cited by 118 publications

References 12 publications

Heating Performance Study on a Passive Solar Heater

Heating Performance Study on a Passive Solar Heater

Recent Developments in Heat Transfer Fluids Used for Solar Thermal Energy Applications

Comparative Performance Analysis of Different Twisted Tape Inserts in the Absorber Tube of Parabolic Trough Collector

Contact Info

Product

Resources

About