Theoretical Study of a Building Cooling Heating Power (BCHP) System Driven by Solar Energy Based on Organic Working Fluid

Author(s):  
Jiangfeng Wang ◽  
Man Wang ◽  
Zhequan Yan ◽  
Yiping Dai

Recently, BCHP systems as a kind of distributed energy resource present a great potential in improving energy efficiency and meeting multiple energy demands. Compared with traditional CCHP systems driven by fossil fuel, on-site renewable energy systems have more advantages in reducing carbon emissions. This paper proposes a new Building Cooling Heating Power system driven by solar energy with flat-plate solar collectors and R245fa as the working fluid. A thermal storage system is integrated into the system to store the collected solar energy and to supply heat when solar radiation is insufficient. By establishing the mathematical models of the proposed system we are able to conduct the numerical simulation of the system working in three typical operation modes around a whole year, namely the Combined Heating Power (CHP) mode in winter, the Combined Cooling Power (CCP) mode in summer, and the power production mode in spring or autumn. Results indicate that the system is able to operate continuously over a day, offering uninterrupted heating, cooling and power to building applications.

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2773
Author(s):  
Petros Siritoglou ◽  
Giovanna Oriti ◽  
Douglas L. Van Bossuyt

This paper presents a user-friendly design method for accurately sizing the distributed energy resources of a stand-alone microgrid to meet the critical load demands of a military, commercial, industrial, or residential facility when utility power is not available. The microgrid combines renewable resources such as photovoltaics (PV) with an energy-storage system to increase energy security for facilities with critical loads. The design method’s novelty complies with IEEE Standards 1562 and 1013, and addresses resilience, which is not taken into account in existing design methods. Several case studies simulated with a physics-based model validate the proposed design method and demonstrate how resilience can be included in the design process. Additionally, the design and the simulations were validated by 24 h laboratory experiments conducted on a microgrid assembled using commercial off-the-shelf components.


Author(s):  
Jon T. Van Lew ◽  
Peiwen Li ◽  
Cho Lik Chan ◽  
Wafaa Karaki ◽  
Jake Stephens

Parabolic trough power systems utilizing concentrated solar energy have proven their worth as a means for generating electricity. However, one major aspect preventing the technologies widespread acceptance is the deliverability of energy beyond a narrow window during peak hours of the sun. Thermal storage is a viable option to enhance the dispatchability of the solar energy and an economically feasible option is a thermocline storage system with a low-cost filler material. Utilization of thermocline storage facilities have been studied in the past and this paper hopes to expand upon that knowledge. The current study aimed to effectively model the heat transfer of a working fluid interacting with filler material. An effective numerical method and efficient computation schemes were developed and verified. A thermocline storage system was modeled under specific conditions and results of great significance to heat storage design and operation were obtained.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Bing Hu ◽  
Xianbiao Bu ◽  
Weibin Ma

To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working fluid types on the system performance were analyzed. The results show that the cooling power per square meter collector and ice production per square meter collector per day depend largely on generation temperature and condensation temperature and they increase firstly and then decrease with increasing generation temperature. For every working fluid there is an optimal generation temperature at which organic Rankine efficiency achieves the maximum value. The cooling power per square meter collector and ice production per square meter collector per day are, respectively, 126.44 W m−2and 7.61 kg m−2 day−1at the generation temperature of 140°C for working fluid of R245fa, which demonstrates the feasibility of organic Rankine cycle powered vapor compression ice maker.


2019 ◽  
Vol 8 (3) ◽  
pp. 7479-7487

There is a growing concern to be self-sufficient and reduce the dependency on external power generating sources to satisfy the energy demands. Issues such as integrated operation of these power sources without having a dedicated storage system with enhanced frequency regulation is to be addressed. In this paper, the distributed generating sources like solar photovoltaic, diesel generator, fuel cells and electric vehicles are considered. Electric vehicle participation in the frequency regulation comes with constraints on state of charge of the battery and availability of the vehicle. An adaptive-additive algorithm is proposed for performing energy resource management and to maintain the frequency within the allowable band during transient and steady state system conditions. Load variation and EV-fleet availability variations are considered in the paper for understanding the system’s response to frequency changes by performing small-signal-analysis. The results show coordinated and satisfactory response of the system to maintain frequency regulation. Economic viability is also focused in the paper.


Author(s):  
Theingi Htun ◽  
Myo Thet Tun

Solar energy can be converted into thermal energy with the help of solar<br />collectors. Electricity can be produced directly from solar energy using<br />photovoltaic devices or indirectly from steam generators using solar thermal collectors to heat a working fluid. This research is using the conversion of solar energy into electricity in a closed cycle driven by natural convection. It would mean that electricity is cheaper than from any other renewable technology and cheaper than from fossil fuels. This paper describes converting thermal energy collected by solar collector to electricity by using turbine. Anywhere in Myanmar will cheaply use electricity by using solar turbine generator. Remote areas will improve more and more when getting the efficient electricity. The design calculation and performance predication of 1 MVA turbo-alternator/generator are also mentioned. Design calculation of absorbed flux, useful heat gain and exit temperature is described. And then development of two-tank thermal storage system that uses molten salt as the heat transfer fluid is described.


2019 ◽  
Author(s):  
Kelsey A Horowitz ◽  
Zachary Peterson ◽  
Michael H Coddington ◽  
Fei Ding ◽  
Benjamin O Sigrin ◽  
...  

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