The effects of volumetric ﬂow rate and inclination angle on the performance of a solar thermal collector Ihaddadene Razika a,⇑ , Ihaddadene Nabila a , Bey Madani a , Hamdibacha Fatima Zohra b a Department of Mechanical Engineering, M’sila University, Algeria b Laboratory of Fluid Mechanics, M’sila University, Algeria article info Article history: Available online xxxx Keywords: Solar energy Solar storage collector Volumetric ﬂow rate Collector inclination Instantaneous collector efﬁciency abstract A solar collector is a device that converts solar energy into heat. This paper presents an experimental study on the inﬂuences of volumetric ﬂow rate and inclination angle on the performance of a solar col- lector. The tests were conducted on a solar energy demonstration system (ET200), which consists of a solar collector, a storage tank, a control and command cabinet and a high power lamp simulating solar energy. For radiation intensity of 1.033 kW/m 2 and inclination angle of 0°, the results showed that the efﬁciency of the collector followed a linear relationship versus the ﬂow rate; g = 0.68  Q v + 49.79 and presented a coefﬁcient of correlation (R 2 ) of 0.9898. Similarly, the increase of the inclination angle from 0° to 60° increased the effectiveness of the collector. A linear relationship; g = 0.43  a + 53.07 with a high coefﬁcient of determination (R 2 = 0.967) relates the collector efﬁciency to the inclination angle. It is important to operate at higher mass ﬂow rates and take the collector angle at 0° in order to reach its meaning full efﬁciency (heating water). Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction The worldwide concern about environment pollution, increased energy prices, continuous reduction of the earth’s conventional fuels resources (80% from the total energy [1]) as well as the in- creased word-wide global warming has led to increasing interest in technologies for the generation of renewable energy. Renewable energy technologies produce marketable energy by converting natural phenomena into useful forms of energy. These technologies use the sun’s energy and its direct and indirect effects on the earth (solar radiation, wind and biomass), gravitational forces (tides) and the heat of the earth’s core (geothermal) as the resources from which energy is produced [2]. The solar energy is the most capable of the alternative energy sources; it is one of the most promising alternatives to the above problems. The de- mand for solar energy has increased by 20% to 25% over the past 20 years [3]. Solar collectors are usually used for active conversion of solar energy into heat. They are the key component of active solar-heat- ing systems. There are a large number of solar collector designs that have shown to be functional. These designs are classiﬁed in three general types of solar collectors; ﬂat-plate collectors, evacu- ated tube collectors and concentrating collectors. In solar water heating systems, incident solar radiation is con- verted into heat and transmitted to a transfer medium such as water [1]. The circulating water from the collector enters to the heat exchanger installed inside the storage tank where it gives its heat to the storage tank water and returns to the solar collector where it is heated again by the solar energy. This system is often viable for replacement of electricity and fossil fuels used for water heating. The thermal efﬁciency of the solar collector (using water or air as a transfer medium) depends strongly on the material, the shape, the size, the disposition of the collector and its surrounding condi- tions. Many authors have paid particular attention to the opera- tional parameters in order to improve the thermal performance of the solar plant. These parameters can be classiﬁed into two main categories the internal and external parameters. The internal ones include the glass, the absorber, the form and the diameter of pipes, the ﬂow ﬂuid, the orientation and inclination of the solar collector and its insulation. The external parameters are temperature, wind, solar radiation and obstacles. In this paper, we have investigated the effects of volumetric ﬂow rate and inclination angle on the performance of a solar col- lector using the radiation of halogen lamp to simulate the sun radiation. 2. Experimental setup The tests were conducted on a fully-functional demonstration model (ET200) of a system for heating domestic water using radi- ation energy. It consists of several devices mounted on a metal support, supervisory and security bodies and its connections to various ﬂuids and energies needed, as illustrated in Fig. 1. 0196-8904/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.enconman.2013.09.051 ⇑ Corresponding author. E-mail address: tassekurt1@gmail.com (I. Razika). Energy Conversion and Management xxx (2013) xxx–xxx Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman Please cite this article in press as: Razika I et al. The effects of volumetric ﬂow rate and inclination angle on the performance of a solar thermal collector. Energy Convers Manage (2013), http://dx.doi.org/10.1016/j.enconman.2013.09.051