scholarly journals Design of a single-acting ammonia-water solar absorption cooling system for food preservation

Author(s):  
Víctor Hugo Hernández-Gómez ◽  
Omar Olvera-García ◽  
Yarabi De la Rosa-Flores ◽  
Iveth Sánchez-Barrera

The increase in the use of non-renewable energy sources and the strong dependence of the energy sector on these sources, encourage the study of applications that use renewable energy sources. In this scenario, there has been an increase in the number of jobs related to refrigeration systems that use other sources of energy in addition to electricity, such as absorption cooling systems, which can produce a cooling effect using mainly heat. residual or other sources such as solar thermal energy. This article presents the design of a cooling system that will operate with solar energy, using the principle of absorption with the ammonia-water working torque in continuous function, to contribute to a cold production alternative in food preservation.

KnE Energy ◽  
2015 ◽  
Vol 2 (2) ◽  
pp. 22
Author(s):  
Andang Widiharto ◽  
Didit Setyo Pamuji ◽  
Atik Nurul Laila ◽  
Fiki Rahmatika Salis ◽  
Luthfi Zharif ◽  
...  

<p>Air conditioning (AC) is one of the most building’s energy consumer, included in building of Engineering Physisc’s Departement, Universitas Gadjah Mada (UGM). The declining of fossil fuel reserves and the increasing effects of global warming, forcing the world to switch to renewable energy sources. This paper discusses the design of solar absorption cooling system to replace conventional AC in seven lecture halls of Engineering Physic’s Departement, UGM. There are some steps that have been done to design the solar absorption cooling, i.e. do a study of the potential availability of solar energy, calculate the cooling loads, analyze the thermodynamic process of the system, determine the type of collector to be used and calculate area of solar collector needed. The thermal coefficient of performance (COP) of the system designed was about 0.84 which could use some types of flat plate solar collector with each area corresponding to each efficiency values. </p><p><strong>Keyword</strong> : Air conditioning; global warming; solar absorption cooling; solar collector</p>


2013 ◽  
Vol 361-363 ◽  
pp. 382-385
Author(s):  
Marek Kušnír ◽  
Danica Košičanová ◽  
František Vranay

Nowadays, choosing of heating source is emphasized. On the market there are different types of heat sources, which need to be properly designed to the required heating output. Finally, it is necessary to take into account the possibilities of fuel burning as well as heat transfer substance. Heating system is dependent on regional weather conditions, where the building is located. All these factors ultimately, with proper design of the heat source, could reduce operating costs in the heating season. Currently in the design of the heating system, there are taken into account the greatest possible energy savings. It is therefore to encourage bigger utilization of renewable energy sources.Currently has the highest proportion of total energy consumption in the buildings, energy for heating. For this reason, the expert and research community seeks to reduce energy consumption at the lowest possible value. For this purpose, people are starting to apply renewable energy sources. These devices using renewable energy sources convert energy from the environment. Most of them are transforming energy from the sun, earth, water and air. This energy is then used directly for heating. In this article we will more closely deal with transforming solar energy into electricity using photovoltaic panels and we will focus on the interaction between the photovoltaic system and heating and cooling system, under certain conditions. Produced electric energy is used for heating system in the school building in Spišská Nová Ves in Slovakia.


2014 ◽  
Vol 1008-1009 ◽  
pp. 31-34
Author(s):  
Mohd Irwan Yusoff ◽  
W.Z. Leow ◽  
M. Irwanto ◽  
N. Gomesh ◽  
M.R. Mamat ◽  
...  

Together with advancement associated with technologies things have gotten simpler and less complicated for people. Automation is usually the employment of manage devices along with details technologies to scale back the need regarding human being do the job inside creation associated with things along with products and services. Solar photovoltaic (PV) technology is regarded as the famous energy source amongst renewable energy sources which in turn that utilize to relieve usage of fossil fuel. PV energy is usually a lot of abundant energy sources among renewable energy. PV technology is change sunlight energy into electrical energy. The performance of electricity of PV module can be affected by solar irradiance and ambient temperature. When PV technology is process solar irradiance, producing lowered performance of PV modules and increasing temperature of PV module. When the temperature of PV module is reach at or more than 35 °C that detected by LM 35, PIC 18F4550 is switched ON the DC cooling system and vice versa. After switch ON the cooling system, the temperature of PV module is reducing. This controller system is an intelligent system because it will run the cooling system automatically when the temperature of PV module reaches setting level that detected by temperature sensors. The higher efficiency of PV cell, the payback period of the system can be shorted and the lifespan of PV module can also be longer.


2011 ◽  
Vol 3 (1) ◽  
pp. 73-77
Author(s):  
Dominykas Vasarevičius

The paper presents the current situation with the renewable energy sources in Lithuania. An overview of legislation promoting the production and usage of renewable energy in Lithuania is presented. Renewable energy production methods suitable for Lithuanian conditions, their advantages and disadvantages are discussed. It is shown that there is no any promotion from the state for usage of solar energy in private households. The potential of solar energy usage is determined. In order to show the effectiveness of solar thermal energy utilization under similar climatic conditions presented the example of promotion policy model and its results in Poland.


2020 ◽  
Vol 10 (8) ◽  
pp. 2761
Author(s):  
María Venegas ◽  
Néstor García-Hernando ◽  
Alejandro Zacarías ◽  
Mercedes de Vega

In this work, the performance of a single effect absorption cooling system fed by solar thermal energy is evaluated. The absorption chiller includes a membrane-based microchannel desorber using three types of nanoparticles: Al2O3, CuO, or carbon nanotubes (CNT). Correlations available in the open literature to calculate the thermal conductivity of nanofluids are reviewed. Using experimental data for the water-lithium bromide solution (H2O-LiBr) with Al2O3 and CNT nanoparticles, the most appropriate correlation for thermal conductivity is selected. Nanofluid properties are evaluated using a concentration of nanoparticles of up to 5% in volume. The largest increase in the desorption rate (7.9%), with respect to using pure H2O-LiBr solution, is obtained using CNT nanoparticles and the maximum concentration of nanoparticles simulated. The performance of the chiller is evaluated and the daily solar coefficient of performance (SCOP) for the solar cooling facility is obtained. The best improvement with respect to the conventional system (without nanoparticles) represents an increase in the cooling effect of up to 6%. The maximum number of desorber modules recommended, always lower than 50, has been identified.


2019 ◽  
Vol 111 ◽  
pp. 01056
Author(s):  
Nur Çobanoğlu ◽  
Ziya Haktan Karadeniz ◽  
Alpaslan Turgut

Renewable energy sources such as solar, wind and geothermal are proposed as an alternative to fossil fuels whose excessive use causes global warming. The most popular one of the renewable energy sources is considered as solar energy due to the fact that required energy is provided by the sun entire year around the world. Solar energy systems convert the solar radiation to the useful heat or electricity. In order to achieve better performance in solar thermal systems many studies have been conducted. Some of these studies suggest that heat transfer fluid could be changed with the nanofluids which can be defined as new generation heat transfer fluid. Nanofluids are suspensions of nano-sized particles such as metals, metal-oxides, and Carbon-allotropes (C), in the conventional base-fluids (water, ethylene glycol and oil). Using nanofluid enhances the efficiency and thermal performance of solar systems due to their better thermophysical and optical properties. Recently, C-based nanofluids are getting attention due to their enhanced thermal conductivity and absorptivity at even low concentrations. The results show that C-based nanofluids have a potential to use in solar energy systems: solar collectors, solar stills, photovoltaic/thermal systems.


IEE Review ◽  
1991 ◽  
Vol 37 (4) ◽  
pp. 152
Author(s):  
Kenneth Spring

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