scholarly journals Analysis on limitation of Using Solar Fraction Ratio as Solar Hot Water System Design and Evaluation Index

2015 ◽  
Vol 70 ◽  
pp. 353-360 ◽  
Author(s):  
Shan Liu ◽  
Bin Hao ◽  
Xilin Chen ◽  
Chunni Yao ◽  
Weiye Zhou
Keyword(s):  
System Design ◽  
Water System ◽  
Hot Water ◽  
Evaluation Index ◽  
Solar Fraction ◽  
System Design And Evaluation

scholarly journals EFFECTIVE SOLAR HOT WATER SYSTEM FOR NORTHERN TERRITORIES

2020 ◽  
Vol 22 (6) ◽  
pp. 119-131
Author(s):  
Yu. O. Krivoshein ◽  
N. A. Tsvetkov ◽  
A. V. Tolstykh ◽  
A. N. Khutornoy ◽  
A. V. Kolesnikova ◽  
...  
Keyword(s):  
Natural Convection ◽  
Thermal Energy ◽  
Water System ◽  
Hot Water ◽  
Remote Access ◽  
Hydraulic Circuit ◽  
Solar Fraction ◽  
Hardware System ◽  
Negative Effect ◽  
Northern Territories

Purpose. The aim of this work is to develop an effective solar hot water system, which eliminates the heat loss of the accumulated thermal energy in the storage tank due to the natural convection of the coolant in the hydraulic circuit of collectors.Design technique. A fullscale experimental study concerns the negative effect of natural convection at night in the experimental industrial hybrid solar hot water system in the developed hard and software with remote access.Results. The pilot industrial hybrid solar system with the improved hydraulic circuit and a soft and hardware system for dispatching and managing energy consumption with remote access was developed, built and tested for Northern territories.Practical implications. The hydraulic circuit of collectors equipped with a controller for switching off the coolant provides the northern conditions to increase the thermal energy in storage tanks and the solar fraction of hot water systems, reduce the fuel consumption in additional system sources and the emission of harmful substances produced by the fuel combustion.Originality/value. It is shown that the use of a solenoid valve to eliminate the natural convection increases the thermal energy storage in tanks by at least 50 % and the solar fraction of systems by at least 20 %.

A Transient Immersed Coil Heat Exchanger Model

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
William R. Logie ◽  
Elimar Frank
Keyword(s):  
Heat Exchanger ◽  
Water System ◽  
Operating Conditions ◽  
Hot Water ◽  
Simulation Environment ◽  
One Dimensional ◽  
Solar Fraction ◽  
Coil Heat Exchanger ◽  
Side Flow ◽  
Coil Heat

The aim of this paper is to present a transient one-dimensional (1D) radial immersed coil heat exchanger model that accounts for the effect that geometry and operating conditions have on heat transfer performance. Insights gained through its use in both an analysis of experimental data and an implementation in the simulation environment TRNSYS are shown and discussed. While variation in the external convection coefficient of immersed coil heat exchangers has little effect on the annual solar fraction of a generic solar domestic hot water system, variation in collector side flow can influence the solar fraction as great as ±5%, in particular low collector side flow improves stratification inside the store.

Stimulation and Optimization of Parabolic Trough Solar Hot Water System

2014 ◽  
Vol 1008-1009 ◽  
pp. 68-72
Author(s):  
Bin Yang ◽  
Wei Wang ◽  
De Gong Zuo
Keyword(s):  
Simulation Model ◽  
Water System ◽  
Hot Water ◽  
Weather Data ◽  
Tube Length ◽  
Parabolic Trough ◽  
Water Load ◽  
Simulation And Optimization ◽  
Solar Fraction ◽  
Different Types

We firstly established stimulation model of parabolic trough solar hot water system with TRNSYS software.Based on the simulation model and the weather data of typical meteorological year in Tianjin,research was made on simulation and optimization from three aspects including the type, the inclination and azimuth,the ratio between the tank volume and the collector area,the water temperature ,the load and the tube length.We found that the efficiency and solar fraction of different types is different in 12 months throughout the year;There are great differences in the performance of different inclination and azimuth;The yearly efficiency and solar fraction will increase with the increase of the ratio between the tank volume and the collector area;When the temperature of water increases, the yearly efficiency and solar fraction will decrease and when the water load increases,the yearly efficiency will increase while the solar fraction will decrease;With increasing of the tube length ,the yearly efficiency and solar fraction will decrease.

Simulation of Dynamical Performance of Solar Desiccant Cooling Cycle

2016 ◽  
Vol 819 ◽  
pp. 160-170 ◽  
Author(s):  
Morteza Khalaji Assadi ◽  
Ali Mohammadi
Keyword(s):  
Energy Consumption ◽  
Water System ◽  
Computer Code ◽  
Hot Water ◽  
Office Building ◽  
Cycle Performance ◽  
Hybrid Mode ◽  
Desiccant Wheel ◽  
Solar Fraction ◽  
Dynamic Cycle

In this research, solar desiccant cooling cycles in ventilation and hybrid mode are simulated. To simulate cycles, at first a model for desiccant wheel simulation is presented and a computer code based on experimental correlations is used to solve equations. Then by TRNSYS software a model for solar hot water system is simulated, and eventually by representing a suitable algorithm, computer program for simulating solar desiccant cooling cycles by EES software is developed. For all components of desiccant cycle, the dynamic optimum were based on regeneration temperature and solar fraction, and after optimum, dynamic cycle performance in an office building with an area of 115 m2 located in Bushehr city, capacity of cooling 3 ton refrigeration were analyzed. The results show that solar desiccant cooling cycles in comparison with compression refrigeration cycles with 40% saving in energy consumption and also during the day and in office buildings have a better performance.

DETERMINING THE PROFITABILITY OF GREENHOUSE ELECTROTECHNOLOGIES: A MODELING APPROACH

HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 249a-249
Author(s):  
Eric A. Lavoie ◽  
Damien de Halleux ◽  
André Gosselin ◽  
Jean-Claude Dufour
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Water System ◽  
Heat Pumps ◽  
Hot Water ◽  
Pump System ◽  
Heat Pump System ◽  
Artificial Lighting ◽  
Hot Air ◽  
Marketable Fruit

The main objective of this research was to produce a simulated model that permitted the evaluation of operating costs of commercial greenhouse tomato growers with respect to heating methods (hot air, hot water, radiant and heat pumps) and the use of artificial lighting for 1991 and 1992. This research showed that the main factors that negatively influence profitability were energy consumption during cold periods and the price of tomatoes during the summer season. The conventional hot water system consumed less energy than the heat pump system and produced marketable fruit yields similar to those from the heat pump system. The hot water system was generally more profitable in regards to energy consumption and productivity. Moreover, investment costs were less; therefore, this system gives best overall financial savings. As for radiant and hot air systems, their overall financial status falls between that of the hot water system and the heat pump. The radiant system proved to be more energy efficient that the hot air system, but the latter produced a higher marketable fruit yield over the 2-year study.

A Design Method for Thermosyphon Solar Domestic Hot Water Systems

1987 ◽  
Vol 109 (2) ◽  
pp. 150-155 ◽  
Author(s):  
M. P. Malkin ◽  
S. A. Klein ◽  
J. A. Duffie ◽  
A. B. Copsey
Keyword(s):  
Flow Rate ◽  
Design Method ◽  
Water Systems ◽  
Hot Water ◽  
Average Flow Rate ◽  
Domestic Hot Water ◽  
Average Flow ◽  
Solar Fraction ◽  
Wide Range ◽  
Flow Circuit

A modification to the f-Chart method has been developed to predict monthly and annual performance of thermosyphon solar domestic hot water systems. Stratification in the storage tank is accounted for through use of a modified collector loss coefficient. The varying flow rate throughout the day and year in a thermosyphon system is accounted for through use of a fixed monthly “equivalent average” flow rate. The “equivalent average” flow rate is that which balances the thermosyphon buoyancy driving force with the frictional losses in the flow circuit on a monthly average basis. Comparison between the annual solar fraction predited by the modified design method and TRNSYS simulations for a wide range of thermosyphon systems shows an RMS error of 2.6 percent.

Problem about Solar Water Heating System and Residential Building Integrated

2012 ◽  
Vol 193-194 ◽  
pp. 30-33
Author(s):  
Xue Ying Wang ◽  
Dong Xu ◽  
Ya Jun Wu
Keyword(s):  
Solar Energy ◽  
Integrated Design ◽  
Water System ◽  
Residential Building ◽  
Heating System ◽  
Hot Water ◽  
Solar Water Heating ◽  
Drainage Design ◽  
Hot Water Supply ◽  
Solar Water Heating System

This article analyzes the problem in application the solar system was used in residential building, puts forward the requirements to use energy and choose the setting of the solar energy collector from two aspects of building and drainage design respectively. In addition, the article explicates andthe solar energy collector and building integrated design and the development of solar energy collector. At last, the article puts forward some Suggestions on the improvement and development of residential solar hot water system and the design of the hot water supply bath solution of practice to make solar energy and low power assisted by night combining.

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