Page 1 of 18
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
online:https://ejbss.org/ P a g e | 1292
STUDY OF DUAL FUNCTION THERMOSYPHON SOLAR HEATING SYSTEM
MARIMUTHU.A
ABSTRACT
The present study aims at enhancing the performance of a novel solar collector
heating system and its usage. A Dual Function Solar Heating System (DFSHS) which can
heat water or air in a combined fashion was designed and fabricated. Experiments were
conducted to highlight the DFSHS performance, usingthermosyphon effect with a
collector tilt angle of 25o
. The DFSHS consists of a solar water heater, a solar air heater
and a heat exchanger connected in series. The performance of the DFSHS was calculated
for fluid (water) flow rates for theabsorber fluids: Water
The absorber fluid first enters into a set of Solar Water Heater (SWH) panels
arranged in parallel and later into the Solar Air Heater (SAH). In the water heating
mode, the hot absorber fluid heats the utility water in a heat exchanger (HEX)
downstream of SAH. In the air heating mode alone, ambient air was made to circulate in
the SAH and absorber fluid connection to HEX was closed. The maximum efficiency
obtained from the solar water heater (SWH) was 73.68% with a flow rate of 0.0225 kg/s
at 13.30 hr during the test period.
I. INTRODUCTION
The demand for energy is increasing at a substantial rate as the economy of the
developing countries is growing. Ever increasing world population is also a major factor for
the increased demand in energy. Currently, this high energy demand is mainly met with the
fossil fuel resources. Apart from the difficulty of meeting the high energy demand, the issue
of environmental pollution with the fossil fuels and its sustainability for future generations
has led to a critical concern on power generation and its utilization. The increase in
Page 2 of 18
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
online:https://ejbss.org/ P a g e | 1293
greenhouse gas emissions and pollutants because of global utilization of fossil fuels has
motivated researchers to pursue research works towards renewable energy sources.
Subsequently, today’s need is power production from renewable resources which are
environmentally benign and sustainable.
Renewable energy sources such as solar energy is one of the long-term options to
substitute conventional energy systems. The greatest advantage of solar energy among other
energies is that it is a clean form of energy source and is supplied without any environmental
contamination, in an unlimited manner. Hot water or steam is a basic need in all civilizations
and industries for several end use applications. Solar water heating systems provides a
solution to reduce fossil fuel consumption and greenhouse gas emissions of
residentialbuildings.
Solar energy can be used by three technological processes namely helio-chemical, helio- electrical and helio-thermal. Among the three processes, the helio-thermal process can be
used to provide much of the thermal energy required for the solar water heating. Solar
thermal technology converts the energy of sun directly into heat, which is stored in the form
of a heated fluid, where normally water is being used as a working fluid. The typical solar
heating system consists of a collector, a heat transfer circuit that includes the
fluid,ameanstocirculateitandastoragesystemincludingaheatexchanger.
Solar energy plays an important role in low-temperature thermal applications, such as
solar heating systems, since it replaces a considerable amount of conventional fuel. Solar
thermal systems which can be used for thermal energy conversion can be classified into
three major categories:
(i) Concentratingtype
(ii) Flat plate collectorsand
(iii) Heliostats.
Page 3 of 18
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 04
April 2019
online:https://ejbss.org/ P a g e | 1294
Out of these, concentrating type collectors are used in high energy / high temperature
applications where electric power generation is of prime importance. On the other hand,
heliostats need large open areas of land with heavy infrastructure and investments. For the
domestic and house-hold applications where low temperature thermal systems are preferred,
flat plate collectors are one of the suitable devices, where a set of tubes were used as a solar
thermal collector.
DETAILS OF THE EXPERIMENTALSETUP
The experimental setup design for the proposed DFSHS was having a unique
combination of solar water heater (SWH) system and a solar air heating (SAH) system
along with a concentric tube type heat exchanger (HEX). The schematic layout of the
DFSHS is shown in Fig.1(a). The DFSHS is oriented facing south and tilted to an angle of
25o with respect to the horizontal to maximize the solar radiation incident on the glass
covers. This makes the FPC
totiltby14o
greaterthanthelatitudeangleatthetestgeographicallocation.
The chosen FPC tilt angle of 14o
(which makes a 25o with horizon) also suits the
recommendation made by Tang et al. (2011), where the authors tested an evacuated tube
solar water heater at two different inclinations 22o
and 46o
. They recommended that for the
buoyancy driven thermal systems, a lower inclination angle is preferred as it was found to
enhance the thermal energy gain. It can also be understood that with increased inclination
angles, the gravitational force component in the downward direction will be large, making
it difficult for the buoyancy driven hot absorber fluid flow in the upward direction.
Experiments were conducted with two different absorber fluids: Water and Thermniol-55.
Water is a common absorber fluid used in the solar thermal systems and Therminol- 55 was
found to be a promising alternative working fluid due to its thermo- physicalproperties.
The DFSHS presently considered for experiments consists of a pair of solar water
heater which is nothing but a flat plate collector (FPC), a solar air heater and a heat
