A new understanding on thermal efficiency of organic Rankine cycle: Cycle separation based on working fluids properties

2018 ◽  
Vol 157 ◽  
pp. 169-175 ◽  
Author(s):  
Yongzhen Wang ◽  
Jun Zhao ◽  
Guibing Chen ◽  
Shuai Deng ◽  
Qingsong An ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluids

Effect of Evaporation Temperature on the Performance of Organic Rankine Cycle in Near-Critical Condition

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Yuping Wang ◽  
Xiaoyi Ding ◽  
Lei Tang ◽  
Yiwu Weng
Keyword(s):  
Thermal Efficiency ◽  
Critical Region ◽  
Critical Condition ◽  
Saturated Vapor ◽  
Organic Rankine Cycle ◽  
Small Variation ◽  
Rankine Cycle ◽  
Inlet Pressure ◽  
Working Fluids ◽  
Evaporation Temperature

Considering the large variations of working fluid's properties in near-critical region, this paper presents a thermodynamic analysis of the performance of organic Rankine cycle in near-critical condition (NORC) subjected to the influence of evaporation temperature. Three typical organic fluids are selected as working fluids. They are dry R236fa, isentropic R142b, and wet R152a, which are suited for heat source temperature from 395 to 445 K. An iteration calculation method is proposed to calculate the performance parameters of organic Rankine cycle (ORC). The variations of superheat degree, specific absorbed heat, expander inlet pressure, thermal efficiency, and specific net power of these fluids with evaporation temperature are analyzed. It is found that the working fluids in NORC should be superheated because of the large slope variation of the saturated vapor curve in near-critical region. However, the use of dry R236fa or isentropic R142b in NORC can be accepted because of the small superheat degree. The results also indicate that a small variation of evaporation temperature requires a large variation of expander inlet pressure, which may make the system more stable. In addition, due to the large decrease of latent heat in near-critical region, the variation of specific absorbed heat with evaporation temperature is small for NORC. Both specific net power and thermal efficiency for the fluids in NORC increase slightly with the rise of the evaporation temperature, especially for R236fa and R142b. Among the three types of fluids, dry R236fa and isentropic R142b are better suited for NORC. The results are useful for the design and optimization of ORC system in near-critical condition.

scholarly journals Comparative investigation of working fluids for an organic Rankine cycle with geothermal water

2015 ◽  
Vol 36 (2) ◽  
pp. 75-84
Author(s):  
Yan-Na Liu ◽  
Song Xiao
Keyword(s):  
Power Generation ◽  
Pressure Ratio ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Comparative Investigation ◽  
Geothermal Water ◽  
Thermodynamic Investigation ◽  
Working Fluids ◽  
Temperature Heat ◽  
Input Pressure

AbstractIn this paper, the thermodynamic investigation on the use of geothermal water (130 °C as maximum) for power generation through a basic Rankine has been presented together with obtained main results. Six typical organic working fluids (i.e., R245fa, R141b, R290, R600, R152a, and 134a) were studied with modifying the input pressure and temperature to the turbine. The results show that there are no significant changes taking place in the efficiency for these working fluids with overheating the inlet fluid to the turbine, i.e., efficiency is a weak function of temperature. However, with the increasing of pressure ratio in the turbine, the efficiency rises more sharply. The technical viability is shown of implementing this type of process for recovering low temperature heat resource.

scholarly journals Evaluation of an Organic Rankine Cycle Using a Non-Imaging Solar Concentrator for Different Working Fluids

2015 ◽  
Vol 3 (3) ◽  
pp. 1-7 ◽  
Author(s):  
Abid Ustaoğlu ◽  
Junnosuke Okajima ◽  
Xin-rong Zhang ◽  
Shigenao Maruyama
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Solar Concentrator ◽  
Working Fluids

scholarly journals Comparative analysis of working fluids for efficient waste heat recovery

2021 ◽  
Vol 2057 (1) ◽  
pp. 012102
Author(s):  
D Ye Lola ◽  
A Yu Chirkov ◽  
Yu A Borisov
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exhaust Gas ◽  
Water Cooling ◽  
Working Fluids ◽  
Gas Recovery ◽  
Recovery System

Abstract The paper analyzes the implementation of plants with an organic Rankine cycle (ORC) on the example of the circuit of the regenerative gas turbine unit and exhaust gas recovery system of the compressor system of the gas-compressor unit. The theoretically achievable values of power generated by the ORC-installations are determined. A criterion is presented for comparing the working fluids according to the efficiency of use in ORC-installations. To evaluate the overall characteristics of the system, the parameters of heat exchangers for air and water cooling were determined. As a result, it is concluded that the use of ORC-installations allows to utilize up to 23% of the heat of exhaust gases (convert into useful work).

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