Evaluation on the Performance of Photovoltaic–Thermal Hybrid System Using CO2 as a Working Fluid

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Chayadit Pumaneratkul ◽  
Haruhiko Yamasaki ◽  
Hiroshi Yamaguchi ◽  
Yuhiro Iwamoto
Keyword(s):  
Power Generation ◽  
Temperature Distribution ◽  
Hybrid System ◽  
Three Dimensional ◽  
Weather Conditions ◽  
Rankine Cycle ◽  
Solar Panel ◽  
Effect Of Temperature ◽  
Working Fluid ◽  
Generation Efficiency

In this study, the CO2-based photovoltaic–thermal hybrid system has been investigated with an objective to increase the power generation efficiency in photovoltaic solar panel and to improve the performance of supercritical CO2 solar Rankine cycle system (SRCS). From a previous study, an improvement of 2% of power generation efficiency was confirmed via experimental investigation. In this study, the temperature distribution on the CO2-based photovoltaic–thermal hybrid system has been numerically and experimentally investigated and confirmed with referenced experimental results. Particularly, in this study, the one-dimensional (1D) calculation of CO2 flow in the cooling tube and three-dimensional (3D) calculation of temperature distribution on the surface of the photovoltaic solar panel are conducted. The typical summer and winter weather conditions are used as the calculation references to investigate the effect of temperature distribution of the photovoltaic solar panel. The results show that the trend of temperature distribution from calculation was confirmed with the experimental data both in summer and winter conditions. Furthermore, in summer condition, the CO2 temperature was increased to a maximum of 28 °C.

Experiments of Low-Grade Heat Organic Rankine Cycle Power Generation Optimal Load Characteristics

2014 ◽  
Vol 529 ◽  
pp. 481-485 ◽  
Author(s):  
Lei Tang ◽  
Yu Ping Wang ◽  
Ping Yang ◽  
Yi Wu Weng
Keyword(s):  
Power Generation ◽  
Heat Source ◽  
Permanent Magnet ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Load Resistance ◽  
Working Fluid ◽  
Generation Efficiency ◽  
Scroll Expander ◽  
Optimal Load

This paper presents the experimental study of the small organic Rankine cycle power system performance under different heat source temperature and different load resistance,1kW experimental system was built using scroll expander with the working fluid R600a. Experimental results show that when heat source temperature does not exceed 120°C, the system has a maximum power for 1.05kW and power generation efficiency of up to 4.51%, the expander rotation speed and expansion ratio can reach 2922rpm and 3.03, respectively; Experiment obtained the variable condition operating characteristics of the scroll expander and permanent magnet generator and the relationship with the load resistance; There exist optimal load resistance to make power generation and unit power output and power generation efficiency maximum at the different heat temperature and different working fluid flow.The scroll expander should match permanent magnet generator and the load resistance when designing systems so that the system can get optimal performance.

scholarly journals Combined Closed Cycle (C3) Systems for Underwater Power Generation

1992 ◽  
Author(s):  
Aristide Massardd ◽  
Gian Marid Arnulfi
Keyword(s):  
Power Generation ◽  
Power Plants ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Primary Energy ◽  
Combined Cycle ◽  
Working Fluid ◽  
Mass Reduction ◽  
Efficiency Increase

In this paper three Closed Combined Cycle (C3) systems for underwater power generation are analyzed. In the first, the waste heat rejected by a Closed Brayton Cycle (CBC) is utilized to heat the working fluid of a bottoming Rankine Cycle; in the second, the heat of a primary energy loop fluid is used to heat both CBC and Rankine cycle working fluids; the third solution involves a Metal Rankine Cycle (MRC) combined with an Organic Rankine Cycle (ORC). The significant benefits of the Closed Combined Cycle concepts, compared to the simple CBC system, such as efficiency increase and specific mass reduction, are presented and discussed. A comparison between the three C3 power plants is presented taking into account the technological maturity of all the plant components.

scholarly journals Addressing Industrial Waste Heat Supply Variability With Organic Rankine Cycle Systems Incorporating Thermal Energy Storage

2021 ◽  
Author(s):  
Bipul Krishna Saha ◽  
Basab Chakraborty ◽  
Rohan Dutta
Keyword(s):  
Power Generation ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Power Plants ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Low Grade

Abstract Industrial low-grade waste heat is lost, wasted and deposited in the atmosphere and is not put to any practical use. Different technologies are available to enable waste heat recovery, which can enhance system energy efficiency and reduce total energy consumption. Power plants are energy-intensive plants with low-grade waste heat. In the case of such plants, recovery of low-grade waste heat is gaining considerable interest. However, in such plants, power generation often varies based on market demand. Such variations may adversely influence any recovery system's performance and the economy, including the Organic Rankine Cycle (ORC). ORC technologies coupled with Cryogenic Energy Storage (CES) may be used for power generation by utilizing the waste heat from such power plants. The heat of compression in a CES may be stored in thermal energy storage systems and utilized in ORC or Regenerative ORC (RORC) for power generation during the system's discharge cycle. This may compensate for the variation of the waste heat from the power plant, and thereby, the ORC system may always work under-designed capacity. This paper presents the thermo-economic analysis of such an ORC system. In the analysis, a steady-state simulation of the ORC system has been developed in a commercial process simulator after validating the results with experimental data for a typical coke-oven plant. Forty-nine different working fluids were evaluated for power generation parameters, first law efficiencies, purchase equipment cost, and fixed investment payback period to identify the best working fluid.

scholarly journals Experimental and Techno-Economic Analysis of Solar-Geothermal Organic Rankine Cycle Technology for Power Generation in Nepal

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Suresh Baral
Keyword(s):  
Power Generation ◽  
Heat Source ◽  
Power Output ◽  
Solar Collector ◽  
Hot Spring ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Maximum Temperature ◽  
Working Fluid ◽  
Working Fluids

The current research study focuses on the feasibility of stand-alone hybrid solar-geothermal organic Rankine cycle (ORC) technology for power generation from hot springs of Bhurung Tatopani, Myagdi, Nepal. For the study, the temperature of the hot spring was measured on the particular site of the heat source of the hot spring. The measured temperature could be used for operating the ORC system. Temperature of hot spring can also further be increased by adopting the solar collector for rising the temperature. This hybrid type of the system can have a high-temperature heat source which could power more energy from ORC technology. There are various types of organic working fluids available on the market, but R134a and R245fa are environmentally friendly and have low global warming potential candidates. The thermodynamic models have been developed for predicting the performance analysis of the system. The input parameter for the model is the temperature which was measured experimentally. The maximum temperature of the hot spring was found to be 69.7°C. Expander power output, thermal efficiency, heat of evaporation, solar collector area, and hybrid solar ORC system power output and efficiency are the outputs from the developed model. From the simulation, it was found that 1 kg/s of working fluid could produce 17.5 kW and 22.5 kW power output for R134a and R245fa, respectively, when the geothermal source temperature was around 70°C. Later when the hot spring was heated with a solar collector, the power output produced were 25 kW and 30 kW for R134a and R245fa, respectively, when the heat source was 99°C. The study also further determines the cost of electricity generation for the system with working fluids R134a and R245fa to be $0.17/kWh and $0.14/kWh, respectively. The levelised cost of the electricity (LCOE) was $0.38/kWh in order to be highly feasible investment. The payback period for such hybrid system was found to have 7.5 years and 10.5 years for R245fa and R134a, respectively.

scholarly journals Modeling Small Scale Solar Powered ORC Unit for Standalone Application

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Enrico Bocci ◽  
Mauro Villarini ◽  
Luca Bove ◽  
Stefano Esposto ◽  
Valerio Gasperini
Keyword(s):  
Power Generation ◽  
Ad Hoc ◽  
Rankine Cycle ◽  
External Support ◽  
Working Fluid ◽  
Small Scale ◽  
Technical Solution ◽  
Solar Panels ◽  
Under Construction ◽  
Photovoltaic Generators

When the electricity from the grid is not available, the generation of electricity in remote areas is an essential challenge to satisfy important needs. In many developing countries the power generation from Diesel engines is the applied technical solution. However the cost and supply of fuel make a strong dependency of the communities on the external support. Alternatives to fuel combustion can be found in photovoltaic generators, and, with suitable conditions, small wind turbines or microhydroplants. The aim of the paper is to simulate the power generation of a generating unit using the Rankine Cycle and using refrigerant R245fa as a working fluid. The generation unit has thermal solar panels as heat source and photovoltaic modules for the needs of the auxiliary items (pumps, electronics, etc.). The paper illustrates the modeling of the system using TRNSYS platform, highlighting standard and “ad hoc” developed components as well as the global system efficiency. In the future the results of the simulation will be compared with the data collected from the 3 kW prototype under construction in the Tuscia University in Italy.

Cycle Analysis of Gas Turbine–Fuel Cell Cycle Hybrid Micro Generation System

2004 ◽  
Vol 126 (4) ◽  
pp. 755-762 ◽  
Author(s):  
Hideyuki Uechi ◽  
Shinji Kimijima ◽  
Nobuhide Kasagi
Keyword(s):  
Power Generation ◽  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Design Parameters ◽  
Material Strength ◽  
Generation Efficiency ◽  
Heating Value ◽  
Micro Gas Turbine ◽  
Lower Heating Value

Hybrid systems, which are based on a micro gas turbine (μGT) and a solid oxide fuel cell (SOFC), are expected to achieve much higher efficiency than traditional μGT’s. In this paper, the effects of cycle design parameters on the performance and feasibility of a μGT-SOFC hybrid system of 30 kW power output are investigated. It is confirmed that the hybrid system is much superior to a recuperated gas turbine in terms of its power generation efficiency and aptitude for small distributed generation. General design strategy is found that less direct fuel input to a combustor as well as higher recuperator effectiveness leads to higher generation efficiency, while higher steam-carbon ratio moderates requirements for the material strength. The best possible conceptual design of a 30-kW μGT-SOFC hybrid system is shown to give power generation efficiency over 65% (lower heating value).

Investigation on Solar-Powered Turbines Using Refrigerant R-134A

2014 ◽  
Author(s):  
Jihad Rishmany ◽  
Michel Daaboul ◽  
Issam Tawk ◽  
Nicolas Saba
Keyword(s):  
Power Generation ◽  
Solar Energy ◽  
Fossil Fuels ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Small Scale ◽  
Combustion Gases ◽  
Water Heaters ◽  
Wide Range ◽  
R 134A

Renewable energy has become a promising solution to substitute fossil fuels in power generation. In particular, the use of solar energy is stretched to a wide range of applications, e.g. photovoltaic cells, solar water heaters, solar space heating, solar thermal plants. However, the combination of solar energy with the Rankine cycle is limited to few applications only. In this context, this study aims in investigating the practicality of employing solar heaters to operate a Rankine cycle for small scale power generation. The working fluid in this study is refrigerant R-134a. Sizing and calculations of the various components of the system are carried out based on a net output power of 1 kW. In comparison with available electricity sources in Lebanon, it was found that the proposed system is currently more expensive than public electricity. However, it can compete with private generators that currently fill the gap in electricity shortage. The main advantage herein lies in the friendly environmental load due to the absence of combustion gases.

Analysis and Optimization of an Ammonia Based Transcritical Rankine Cycle for Power Generation

2008 ◽  
Author(s):  
Jahar Sarkar ◽  
Souvik Bhattacharyya
Keyword(s):  
Power Generation ◽  
Low Temperature ◽  
Thermal Efficiency ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Heat Sources ◽  
High Side ◽  
Water Based ◽  
Temperature Heat ◽  
Transcritical Rankine Cycle

This study presents the potential of ammonia as a working fluid in transcritical Rankine cycle for power generation using both high and low temperature heat sources. Higher heat capacity value and superior heat transfer properties of ammonia compared to water are the motivating factors behind its use as a working fluid. A thermodynamic analysis for the ammonia based transcritical Rankine cycle and its comparison with the water based Rankine cycle is presented. Analyses with several cycle modifications are also presented to study the thermal efficiency augmentation. It is observed that an optimum high side pressure exists for near critical operation. In case of low temperature heat sources such as solar energy or waste heat, where water based systems are not suitable, ammonia based Rankine cycle is applicable with attractive thermal efficiency, although cycle modification is not possible. The results with high temperature heat source such as boiler or nuclear reactor, where the turbine outlet is in superheated zone, show that simple ammonia systems yield lower efficiency than water, although a recompression cycle with regenerative heat exchangers exhibits higher efficiency than water. Significant thermal efficiency improvement can be achieved by increasing the high side cycle pressure. Recompression Rankine cycle can be a potential alternative with proper design measures taken to avoid toxicity and flammability.

Experimental Study of the Influence of Light Intensity on Solar Organic Rankine Cycle Power Generation System

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Yuping Wang ◽  
Lei Tang ◽  
Yiwu Weng
Keyword(s):  
Power Generation ◽  
Fluid Flow ◽  
Light Intensity ◽  
Turning Point ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Experimental Facility ◽  
Generation System ◽  
Power Generation System

A low-temperature (<120 °C) solar organic Rankine cycle (ORC) power generation experimental facility is designed and built. The influence of light intensity on the system performance is investigated using the experimental facility. The results indicate that the system efficiency can reach 2.2%. The temperature of heat transfer fluid (HTF) decreases linearly with light intensity (I). However, both system efficiency and thermoelectric efficiency first decrease linearly and then drop sharply as I decreases at working fluid flow rates (Vwf) of 200 and 160 L/hr, while they only decrease slightly with I at Vwf of 120 L/hr. The light intensity of the turning point is 824 W/m2 at Vwf of 200 L/hr, which corresponds to an HTF temperature of 75 °C. In addition, it is found that the influence of light intensity on the performance of ORC becomes stronger for higher working fluid flow rate. Moreover, the light intensity and HTF temperature at the turning point increase with working fluid flow rate. The experimental results are of great significance for the design and operation of low-temperature solar ORC power generation system.

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