Solar thermal collector

Kalogirou, A.S. 2004b. Solar thermal collectors and applications. Progress Energy Combus Sci 30 231-295. 

High-Temperature Collector A solar thermal collector designed to operate at a temperature of 180 degrees Fahrenheit or higher. 

Liquid Collector A medium-temperature solar thermal collector, employed predominantly in water... 

Low-Temperature Collectors Metallic or nonmetallic solar thermal collectors that generally operate at temperatures below 110 degrees Fahrenheit and use pumped liquid or air as the heat-transfer medium. They usually contain no glazing and no insulation, and they are often made of plastic or rubber, although some are made of metal. 

Solar Thermal Collector A device designed to receive solar radiation and convert it into thermal energy. Normally, a solar thermal collector includes a frame, glazing and an absorber, together with the appropriate insulation. The heat collected by the solar thermal collector may be used immediately or stored for later use. Typical use is in solar hot water heating systems. Also, see Passive Solar and Concentrated Solar Power (CSP). ... 

Total shipments as reported by respondents include all domestic and export shipments and may include imported collectors that subsequently were shipped to domestic or foreign customers. Includes shipments of solar thermal collectors to the government, including some military, but excluding space applications. 

Includes shipments of solar thermal collectors to the government, including some military, but excluding space applications. 

Anon., Materials in Solar Thermal Collectors Identification of New Types of Transparent Polymeric Materials, Report 1996-11-08, lEA Solar Heating and Cooling Programme, Brussels, Belgium, 1996. 

Figure 5.89. The hourly amount of heat for space heating and hot water produced by solar thermal collectors in the 2050 scenario.

The benefits of solar thermal collectors, as the rooftop panels that heat water using the sun s energy are called, are numerous they require very little maintenance they have virtually no running costs they usually only take a day to install and, in some cases, you don t require building permits. 

There are now quite a few solar thermal collector manufacturers, but it s worth shopping around. 

Most companies will send a licensed installer to your home to give you a quote based on your specific needs. Another option is to install a solar thermal collector yourself. Many energy organizations, and even manufacturers themselves, give short courses on installation and maintenance. 

The solar thermal collector is installed on your rooftop. South-facing roofs pitched at a 35-40° angle are preferable, but not strictly necessary. 

Photovoltaic solar panels cells convert the sun s radiation into electricity and, like solar thermal collectors (which heat water), are a free source of energy sitting on your roof. A solar panel could provide up to half your electricity needs through the year. 

OEM Thermafin copper absorber plates and flat plate solar thermal collectors. Tel 1.800.874.2190... 

Most of the reactor designs tested for the photooxidation of organic pollutants by solar radiation are Ti02 slurry reactors. The implementation of solar photocatalytic reactors has occurred concurrently with advances in thedesign of solar thermal collectors, given the important characteristics shared by these units. There are, however, specific constraints for the design of solar photocatalytic reactors. 

Absorber - The component of a solar thermal collector that absorbs solar radiation and converts it to heat, or, as in a solar photovoltaic device, the material that readily absorbs photons to generate charge carriers (free electrons or holes). 

Array (Solar) - Any number of solar photovoltaic modules or solar thermal collectors or reflectors connected together to provide electrical or thermal energy. 

Flow Condition - In reference to solar thermal collectors, the condition where the heat transfer fluid is flowing through the collector loop under normal operating conditions. 

Trickle (Solar) Collector - A type of solar thermal collector in which a heat transfer fluid drips out of header pipe at the top of the collector, runs down the collector absorber and into a tray at the bottom where it drains to a storage tank. 

Tube-In-Plate-Absorber - A type of solar thermal collector where the heat transfer fluid flows through tubes formed in the absorber plate. 

The aim of the solar thermal collector development is to improve and optimize them for the temperature level from 80 °C to 250 °C. There are different approaches like double-glazed flat plate collectors with anti-reflection coated glazing, stationary compound parabolic concentrator (CPC) collectors, evacuated tube collectors, vacuum flat plate collectors, small parabolic trough collectors, linear concentrating Fresnel collectors and a concentrating collector with a stationary reflector. 

The collector efficiency curve is a good indication for the performance of a collector at different operating temperatures. Optical and thermal losses influence the efficiency of a collector. Thermal losses depend on the temperature at which the solar thermal collector is operating. Simple constructed collectors like an unglazed swimming pool collector have high losses already at relatively low temperatures. Process heat collectors have special... 

FIGURE 13 Comparative peak performance for a tracking parabolic trough, an ISEC, contemporary (external reflector) evacuated CPCs (triangles) and flat plates. The ISEC s superior performance up to temperatures above 200°C, achieved with no moving parts, makes it an extremely flexible solar thermal collector. 

Compound parabolic concentrators permit the use of low to moderate levels of concentration for solar thermal collectors without the requirement of diurnal tracking. When used in conjunction with an evacuated absorber with selective surfaces, a fully stationary CPC (designs with concentrations of l.l-1.4x are now commercially available) has a typical efficiency of about 40% at 150°C (270°F) above ambient with available conventional materials. An experimental 5x CPC requiring approximately 12 tilt adjustments annually, when used with a similar available evacuated absorber, has a measured efficiency of 60% at 220°C above ambient and is capable of efficiencies near 50% at 300°C. With such thermally efficient absorbers, higher concentrations are not necessary or desirable. 

Trombe walls also use the principle of thermal mass. A Trombe wall consists of a thick solid wall of concrete or other dense material, open at the top and bottom to allow convective air circulation. A second outer wall of glass windows adjacent to the solid wall acts as the solar thermal collector. 

Not only are the stresses directly caused by the operational temperatures important, but the module temperature as part of the microclimate is also a major parameter for the other microclimatic properties. The most important property is the surface humidity, but also the photodegradation by UV irradiation might be accelerated by the sample temperature. Numerous models have been proposed for the simulation of the module temperature and are discussed in a comprehensive overview [2]. One of the models was derived from the energy balance for a solar thermal collector by David Faiman [3] ... 

Yuste M, et al. Correlation between structure and optical properties in low emissivity coatings for solar thermal collectors. Thin Solid Films 2010 518(20) 5720-3. 

Abstract. Usual plate solar collectors, based on a metal absorber (Cu, Al) selectively coated are technologically very sophisticated, expensive to produce and they are great consumer of fossil raw material. Polymeric materials are considered as a promising alternative for many interesting properties easy moldability, corrosion resistance, they also offer a significant cost-reduction for solar thermal collectors, and a mass production may thus benefit to a broader utilization of solar energy. Most drawbacks of polymers are their low thermal properties essentially thermal conductivity coefficient may strongly affect the solar absorber efficiency and deteriorate the collector performance. 

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