scholarly journals Study of Using Solar Thermal Power for the Margarine Melting Heat Process

2014 ◽  
Vol 137 (2) ◽  
Author(s):  
Mohamed A. Sharaf Eldean ◽  
A. M. Soliman

The heating process of melting margarine requires a vast amount of thermal energy due to its high melting point and the size of the reservoir it is contained in. Existing methods to heat margarine have a high hourly cost of production and use fossil fuels which have been shown to have a negative impact on the environment. Thus, we perform an analytical feasibility study of using solar thermal power as an alternative energy source for the margarine melting process. In this study, the efficiency and cost effectiveness of a parabolic trough collector (PTC) solar field are compared with that of a steam boiler. Different working fluids (water vapor and Therminol-VP1 heat transfer oil (HTO)) through the solar field are also investigated. The results reveal the total hourly cost ($/h) by the conventional configuration is much greater than the solar applications regardless of the type of working fluid. Moreover, the conventional configuration causes a negative impact to the environment by increasing the amount of CO2, CO, and NO2 by 117.4 kg/day, 184 kg/day, and 74.7 kg/day, respectively. Optimized period of melt and tank volume parameters at temperature differences not exceeding 25 °C are found to be 8–10 h and 100 m3, respectively. The solar PTC operated with water and steam as the working fluid is recommended as a vital alternative for the margarine melting heating process.

Author(s):  
Khamid Mahkamov ◽  
Piero Pili ◽  
Roberto Manca ◽  
Arthur Leroux ◽  
Andre Charles Mintsa ◽  
...  

The small solar thermal power plant is being developed with funding from EU Horizon 2020 Program. The plant is configured around a 2-kWel Organic Rankine Cycle turbine and solar field, made of Fresnel mirrors. The solar field is used to heat thermal oil to the temperature of about 240 °C. This thermal energy is used to run the Organic Rankine Cycle turbine and the heat rejected in its condenser (about 18-kWth) is utilized for hot water production and living space heating. The plant is equipped with a latent heat thermal storage to extend its operation by about 4 hours during the evening building occupancy period. The phase change material used is Solar salt with the melting/solidification point at about 220 °C. The total mass of the PCM is about 3,800 kg and the thermal storage capacity is about 100 kWh. The operation of the plant is monitored by a central controller unit. The main components of the plant are being manufactured and laboratory tested with the aim to assemble the plant at the demonstration site, located in Catalonia, Spain. At the first stage of investigations the ORC turbine will be directly integrated with the solar filed to evaluate their joint performance. During the second stage of tests, the Latent Heat Thermal Storage will be incorporated into the plant and its performance during the charging and discharging processes will be investigated. It is planned that the continuous filed tests of the whole plant will be performed during the 2018–2019 period.


Author(s):  
Klaus-Ju¨rgen Riffelmann ◽  
Daniela Graf ◽  
Paul Nava

From 1984 to 1992, the first commercial solar thermal power plants — SEGS I to IX — were built in the Californian Mojave desert. The first generation of trough collectors (LS1) used in SEGS I showed an aperture area of about 120 m2 (1’292 ft2), having an aperture width of 2.5 m (8.2 ft). With the second generation collector (LS2), used in SEGS II to VI, the aperture width was doubled to 5 m (16.4 ft). The third generation (LS3) has been increased regarding width (5.76 m or 18.9 ft) and length (96 m or 315 ft) to about 550 m2 (5’920 ft2) aperture. It was used in the last SEGS plants VIII and IX, those plants having a capacity of 80 MW each. After more than 10 years stagnancy, several commercial plants in the US (the 64 MW Nevada Solar One project) and Spain (the ANDASOL projects, 50 MW each with 8 h thermal storage) started operation in 2007/2008. New collectors have been developed, but all are showing similar dimensions as either the LS2 or the LS3 collector. One reason for this is the limited availability of key components, mainly the parabolic shaped mirrors and heat collection elements. However, in order to reduce cost, solar power projects are getting larger and larger. Several projects in the range of 250 MW, with and without thermal storage system, are going to start construction in 2011, requiring solar field sizes of 1 to 2.5 Million m2. FLABEG, market leader of parabolic shaped mirrors and e.g. mirror supplier for all SEGS plants and most of the Spanish plants, has started the development of a new collector generation to serve the urgent market needs: lower cost and improved suitability for large solar fields. The new generation will utilize accordingly larger reflector panels and heat collection elements attended by advanced design, installation methods and control systems at the same time. The so-called ‘Ultimate Trough’ collector is showing an aperture area of 1’667 m2 (17’944 ft2), with an aperture width of 7.5 m (24.6 ft). Some design features are presented in this paper, showing how the new and huge dimensions could be realized without compromising stiffness, and bending of the support structure and improving the optical performance at the same time. Solar field layouts for large power plants are presented, and solar field cost savings in the range of 25% are disclosed.


2020 ◽  
Vol 4 (2) ◽  
pp. 36
Author(s):  
Ahmed Remlaoui ◽  
M. Benyoucef, D. Assi, D. Nehari .

This paper presents a validated TRNSYS model for a thermodynamic plant with parabolic trough solar thermal power (PT). The system consist of trough solar collector (PTC) as well as auxiliary components.. The simulation of the system has been done during the day (01/01) under the meteorological conditions of Ain Témouchent city (Algeria). The model compared the energy performance of the systems: case (1) - Rankine cycle facility with solar field and case (2)- Rankine cycle facility without solar field. The results showed that the present model has a good agreement with the experimental data of the literature. In case (1), PTC fluid outlet temperature reach the maximum value 330 ° C, Work of the steam turbine increase from the 9hr to reach its maximum value 856 KJ/Kg at 13 hr. In case (2), the maximum value of the power remains constant from the beginning of the simulation to 1hr00. Since the flow of fuel (gas natural) consumed does not change throughout the operating period. 


1999 ◽  
Vol 121 (2) ◽  
pp. 91-97 ◽  
Author(s):  
D. Yogi Goswami ◽  
Feng Xu

A combined thermal power and cooling cycle is proposed which combines the Rankine and absorption refrigeration cycles. It can provide power output as well as refrigeration with power generation as a primary goal. Ammonia-water mixture is used as a working fluid. The boiling temperature of the ammonia-water mixture increases as the boiling process proceeds until all liquid is vaporized, so that a better thermal match is obtained in the boiler. The proposed cycle takes advantage of the low boiling temperature of ammonia vapor so that it can be expanded to a low temperature while it is still in a vapor state or a high quality two phase state. This cycle is ideally suited for solar thermal power using low cost concentrating collectors, with the potential to reduce the capital cost of a solar thermal power plant. The cycle can also be used as a bottoming cycle for any thermal power plant. This paper presents a parametric analysis of the proposed cycle.


Author(s):  
Thomas A. Cooper ◽  
James S. Wallace

A preliminary design and feasibility study has been conducted for a 200 kWe solar thermal power plant for operation in Ontario. The objective of this study is to assess the feasibility of small-scale commercial solar thermal power production in areas of relatively low insolation. The design has been developed for a convention centre site in Toronto, Ontario. The plant utilizes a portion of the large flat roof area of the convention centre to accommodate the collector array. Each power plant module provides a constant electrical output of 200 kWe throughout the year. The system is capable of maintaining the constant output during periods of low insolation, including night-time hours and cloudy periods, through a combination of thermal storage and a supplemental natural gas heat source. The powerplant utilized the organic Ranking cycle (ORC) to allow for relatively low source temperatures from the solar collector array. A computer simulation model was developed to determine the performance of the system year-round using the utilizability-solar fraction method. The ORC powerplant uses R245fa as the working fluid and operates at an overall efficiency of 11.1%. The collector is a non-concentrating evacuated tube type and operates at a temperature of 90°C with an average annual efficiency of 23.9%. The system is capable of achieving annual solar fractions of 0.686 to 0.874 with collector array areas ranging from 30 000 to 40 000 m2 and storage tank sizes ranging from 3.8 to 10 × 106L respectively. The lowest possible cost of producing electricity from the system is $0.393 CAD/kWh. The results of the study suggest that small-scale solar thermal plants are physically viable for year round operation in Ontario. The proposed system may be economically feasible given Ontario’s fixed purchase price of $0.42 CAD/kWh, but the cost of producing electricity from the system is highly dependent on the price of the solar collector.


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