Techno-economic analysis of new integrated system of humid air turbine, organic Rankine cycle, and parabolic trough collector

Since the humid air turbine (HAT) cycle was first presented by Rao and Joiner (1990), several modifications were proposed to the original configuration to further improve its efficiency. In the last years, the attention was focused in the water recovery from flue gas and in determining the most suitable systems to separate water from gas and solving the problem of low temperature at the stack. In all the above studies it was shown that condensing water from flue gas requires a significant flow rate of a cooling medium (generally water) which is needed to remove condensation heat which must then be disposed in the environment. This worsens power plant performance because large cooling towers are needed. On the other hand, the reduced cost of water treatment may compensate the additional costs of the condensation equipment. In this paper, the introduction of an Organic Rankine Cycle (ORC), which transforms in mechanical power a fraction of the heat recovered from the HAT cycle, both in the water recovery system and in other heat exchangers, is presented. Results were obtained by using three different fluids and maximizing the ORC input exergy. The substances which were used are the conventional R502 refrigerant fluid, ammonia and the new HF134a, which is replacing phased-out CFCs in refrigeration systems.

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Techno-Economic Analysis of Biofuel, Solar and Wind Multi-Source Small-Scale CHP Systems

Energies ◽

10.3390/en13113002 ◽

2020 ◽

Vol 13 (11) ◽

pp. 3002 ◽

Cited By ~ 1

Author(s):

Angelo Algieri ◽

Pietropaolo Morrone ◽

Sergio Bova

Keyword(s):

Economic Analysis ◽

Wind Turbine ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Integrated System ◽

Photovoltaic System ◽

Small Scale ◽

System Efficiency ◽

Global System ◽

Partial Load

The aim of the paper is the techno-economic analysis of innovative integrated combined heat and power (CHP) systems for the exploitation of different renewable sources in the residential sector. To this purpose, a biofuel-driven organic Rankine cycle (ORC) is combined with a wind turbine, a photovoltaic system and an auxiliary boiler. The subsystems work in parallel to satisfy the electric and heat demand of final users: a block of 40 dwellings in a smart community. A 12.6 kWel ORC is selected according to a thermal-driven strategy, while wind and solar subsystems are introduced to increase the global system efficiency and the electric self-consumption. The ORC can be switched-off or operated at partial load when solar and/or wind sources are significant. A multi-variable optimization has been carried out to find the proper size of the wind turbine and photovoltaic subsystems and to define the suitable operating strategy. To this purpose, several production wind turbines (1.0–60.0 kWel) and photovoltaic units (0.3–63.0 kWel) have been considered with the aim of finding the optimal trade-off between the maximum electric self-consumption and the minimum payback period and electric surplus. The multi-objective optimization suggests the integration of 12.6 kWel ORC with 10 kWel wind turbine and 6.3 kWel photovoltaic subsystem. The investigation demonstrates that the proposed multi-source integrated system offers a viable solution for smart-communities and distributed energy production with a significant improvement in the global system efficiency (+7.5%) and self-consumption (+15.0%) compared to the sole ORC apparatus.

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SIZING A PARABOLIC TROUGH COLLECTOR FOR A MICRO SOLAR ORGANIC RANKINE CYCLE

Jurnal Teknologi ◽

10.11113/jt.v81.12304 ◽

2019 ◽

Vol 81 (2) ◽

Author(s):

Choi Yun Chai ◽

Hyung-chul Jung

Keyword(s):

Power Generation ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Operating Conditions ◽

Working Fluid ◽

Solar Thermal Energy ◽

Parabolic Trough ◽

Tropical Country ◽

Parabolic Trough Collector ◽

Time Operation

There are many remote villages in Malaysia that are not connected to an electric grid, and are dependent on expensive diesel generator sets (gensets) in their daily activities. Malaysia, a tropical country, has the potential to promote solar power generation in these isolated areas. The organic Rankine cycle (ORC) using solar thermal energy as the heat source could be an attractive approach to off-grid power generation. In this study, a 1 kWe solar ORC with a parabolic trough collector (PTC) is proposed. The ORC utilizes R245fa as the working fluid and Therminol VP1 as the heat transfer medium between the PTC and ORC. Thermodynamic analysis of the ORC is performed, predicting the performance of the ORC and the operating conditions of the PTC. Based on the design requirements of the PTC from the power cycle analysis, process of sizing the PTC is conducted via a numerical model. Seven sets of heat collector elements (HCE) are examined. The effects of absorber tube material, selective coating on the outer surface of the absorber tube, and the absorber tube diameter on the PTC performance are presented. Simulation results show that HCE with 6 mm of SS316L absorber tube, enclosed with 11 mm of Pyrex borosilicate glass tube, has the highest collector efficiency of 62.25%. The receiver length required is 8.05 m and the aperture width of the collector is 3.54 m. Further study is recommended to select a thermal storage system for night-time operation of the ORC.

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