Waste heat dissipated in the exhaust system in a combustion engine represents a major source of energy to be recovered and converted into useful work. A waste heat recovery system (WHRS) based on an Organic Rankine Cycle (ORC) is a promising approach, and has gained interest in the last few years in an automotive industry interested in reducing fuel consumption and exhaust emissions. Understanding the thermodynamic response of the boiler employed in an ORC plays an important role in steam cycle performance prediction and control system design. The aim of this study is therefore to present a methodology to study these devices by means of pattern recognition with infrared thermography. In addition, the experimental test bench and its operating conditions are described. The methodology proposed identifies the wall coordinates, traces paths, and tracks wall temperature along them in a way that can be exported for subsequent post-processing and analysis. As for the results, through the wall temperature paths on both sides (exhaust gas and working fluid) it was possible to quantitatively estimate the temperature evolution along the boiler and, in particular, the beginning and end of evaporation.

This article explores the geothermal resources of Kazakhstan's Zharkent Basin, with a specific focus on the high-temperature geothermal sources in the Almaty region of Southern Kazakhstan. The research aims to analyze the energy characteristics of the Organic Rankine Cycle (ORC) for harnessing low-enthalpy geothermal energy for small-scale electricity generation. A detailed thermodynamic model was developed, employing R134a as the working fluid. An in-depth analysis of the Zharkunak field (Zharkent, Almaty region) revealed that well 5539, with its notably high temperatures, offers the highest potential for geothermal electricity production, achieving an annual output of approximately 10,371 MWh. The total electric power output from the studied wells in the region is estimated at 20,111 MWh annually, representing a significant contribution towards sustainable energy production and reducing reliance on traditional coal-fired power plants. The study concludes that the Organic Rankine Cycle is not only a viable and efficient technology for utilizing low-enthalpy geothermal resources to generate electricity on a small scale, but also a key player in enhancing energy independence. By leveraging local geothermal energy, the Almaty region can significantly reduce its reliance on external energy sources, thereby fostering sustainable development and reducing environmental impacts.

Results of profile loss measurements, including trailing edge flow details, are presented for the flow of an organic vapor through a linear turbine cascade. The so-called VKI-I blade profile from the open literature was chosen for the cascade, and the working fluid was NOVEC 649. Pitot probes and hot wire anemometry were employed to measure the flow field up and downstream of the cascade. Details of the unsteady flow caused by the trailing edge of the blades and the turbulent spectrum were investigated using hot-wire anemometry. The new organic vapor flow results were compared with literature data obtained for air and with the prediction of conventional literature loss models. It was found that under certain thermodynamic conditions, specific traditional loss models can reasonably predict organic Rankine cycle (ORC) turbines' profile loss. Still, significant deviations between the loss models and the experimental data can also occur.

The paper presents the results of energy and environmental analysis of geothermal CHP plant operation in Polish conditions. As the most favorable, for the geothermal conditions prevailing in Poland, the variant of CHP plant based on Organic Rankine Cycle (ORC) has been taken into consideration. As the case study the existing geothermal well located in the town of Konin in the Wielkopolska voivodship has been chosen. The conceptual design of CHP plant has been proposed and evaluated from energy and environmental point of view. As energy performance criteria the non-renewable primary energy consumption has been chosen. In case of environmental performance carbon dioxide emission has been taken as evaluation criteria. The analysis has been performed for different operating conditions and three working fluids.