Waste heat recovery plays an important role in energy resource management. Low grade waste heat could be recovered by Organic Rankine Cycle (ORC). This is the same as the Rankine cycle and an organic fluid is used as working fluid. In this work the effects of using two-component mixtures with different temperature glides during phase change، on performance of Organic Rankine Cycle are studied. Four two-component mixtures are selected: n-pentane/n-butane، isopentane/isobutene، n-pentane/isobutene and isopentane/n-butane. In this study for more reasonable comparison of thermal recovery the inlet and outlet temperatures of heat source heat carrier fluid and its mass flow rate are considered to be constant. Results show that in the use of two-component mixtures in comparison with pure fluids، approximately 9% increase in energetic and exergetic efficiencies for simple configuration and 14% in configuration with the internal heat exchanger can be achieved with respect to the temperature glide match in the condenser and evaporator.

Pinch technology has been employed as an important tool for the heat integration of petroleum refining processes. The thermal integration of heat pumping system is done by this technology. A heat pump is a system that takes low level heat from a source and delivers it to a sink where higher heat load and temperature levels are required. Heat pump integration in separation columns operates between the condenser as heat source and the reboiler as a heat sink. Therefore، it operates by extracting an amount of heat from a source with a relatively low temperature and delivering a larger amount of heat to a sink with a higher temperature by consuming high quality energy. In this study، the proper heat integration feasibility of a heat pump is done in the LPG process of Tehran oil refinery، which resulted in a $ 144،000 annual savings in energy cost.

In this paper, a new method was presented for recovering dissipated heat in the exhaust of GM Isota floating engine and converting it to electricity using a flexible thermal anchor. The flexure uses three parallel arms including the hot and cold arms to control temperature and generate electrical power. Also, three dimples were used in the shortest arm for thermal stability in order to control the core temperatures. In other words, the purpose of the present paper was developing a passive heat transfer method and a heat generating system was employed for recovering dissipated heat to generate electrical power. Size of proposed design was equal to 40µm × 250µm, and it was implemented and simulated in COMSOL software 2018. Simulation results for proposed design with the voltage of 5V and maximum temperature of 550K presented acceptable FOM compared to similar work such that it showed the value of 2.3 times relative to the best design ,and it was 2700 times better compared to the worst design.

Waste heat dissipation from spacecraft subsystems is crucial due to spatial limitations (no convective heat transfer, limited electrical power, lightweight, and high reliability). Radiators are often responsible for collecting and dissipating this waste heat into cold space. Panel radiators are widely used in various satellites, including scientific, communication, and remote sensing satellites. In scientific satellites, panel radiators are used to dissipate heat generated by scientific instruments such as cameras and spectrometers. In communication satellites, panel radiators are used to dissipate heat generated by power amplifiers. In remote sensing satellites, panel radiators are used to dissipate heat generated by sensors and processors. High efficiency, light weight, and high reliability are the advantages of using this equipment. The main challenge in using it is to provide sufficient heat dissipation area and uniformity of the surface temperature when radiating waste heat to the cold environment (space). The use of heat pipes in the panel radiator structure provides this uniformity. A heat pipe radiator consists of a sandwich panel with an embedded network of heat pipes. Increasing the number of heat pipes reduces the temperature gradient across the radiator surface but increases the radiator weight. Due to the importance of equipment lightness in space systems, optimization of the number of pipes and their geometric arrangement in the radiator should be such that maximum temperature uniformity on the surface and minimum radiator weight are achieved. The objective of this research is to optimize the performance of a radiator (maximum temperature uniformity on the surface) to achieve minimum weight while considering the weight and size constraints imposed by the system designer as requirements. Initially, a mathematical model is developed and solved numerically, and the effect of design parameters on the performance of a panel radiator, including face and core thickness, spacing between heat pipes, mass, and surface area, is comprehensively investigated. Based on the simulation results, considering the weight limitations and existing face and core thicknesses, the maximum allowable spacing between heat pipes is calculated to achieve maximum efficiency of the panel radiator. A network of heat pipes with this characteristic was produced and used in the panel sandwich. The results obtained from testing the manufactured panel radiator were compared with the design efficiency to validate the model. Based on the experimental results, an efficiency of 89% was obtained at a root temperature of 39°C. The error of this efficiency with the efficiency calculated from the theory is about 3%.

In this study, the hybrid of organic Rankine cycle with heat recovery system of low temperature gases in Electric Arc furnace has been investigated. Moreover, the effect of the steam accumulator on stabilizing the mass and heat of exhaust gases of the heat recovery boiler is shown. Hence, constant thermal power has been achieved for a longer period of time for the organic Ranking cycle. The steam accumulator thermodynamic model is simulated based on the non - equilibrium thermal model for the liquid and vapor phases. Furthermore, the steam accumulator pressure variations with different mass outflow rates have been investigated. Constant and continuous thermal power has been reached with an output mass flow rate of 2.84 kg/s during four processes of the electric arc furnace. The transient state of the aforementioned hybrid system has been studied from the energy and exergy points of view. The energy and exergy efficiencies of the whole system are calculated with three working fluids Hexamethyldisiloxane, Toluene, and R245fa of the organic Ranking cycle. Toluene with thermal and exergy efficiencies of 16.4% and 27.1%, respectively, is suitable for use in the organic Ranking cycle compared with the other two fluids.

The quantum synchronization and correlation have been studied between two coupled dissipative van der pol oscillators in a quantum system. Using the master equation approach, this study calculated mutual information, entanglement and synchronization error and investigated the effect of dissipative coupled on quantum synchronization and correlations of two coupled dissipative van der pol oscillators, considering the effect of temperature change in the squeeze states,. The results show that increasing the temperature in the squeeze states has a negative effect on the quantum synchronization and quantum correlation, while mutual information, which is the sum of classical and quantum correlations, indicates a decrease.

The considerable amount of internal combustion engine waste heat through exhaust gases and the capability of adsorption cooling system to be driven by waste heats cause adsorption cooling systems to be interesting for vehicle air conditioning. Low specific cooling power of these systems leads them to be bulkier with respect to other cooling systems. Therefore, practical use of these system has been a challenge. One of the methods to enhance the system performance is adsorber bed optimization which is only feasible by numerical simulations. Hence, an exhaust waste heat driven adsorption cooling system with longitudinal finned-tube adsorber is simulated three dimensionally and considering heat and mass transfer details. Also, both the intra-particle and inter-particle mass transfer resistance has been taken into account in governing equations in order to study the effect of adsorbent particle diameter on the system performance. Results show that among the examined geometrical configurations, bed with 20 fin numbers and fin height of 10 mm is the optimum case corresponding to the maximum specific cooling power. In addition, adsorbent particle diameter in the range of 0.3-0.4 mm is the most suitable diameter for the adsorber bed packed with zeolite13x grains.

The energy crisis around the world justifies the exploitation of projects centered on the use of waste energy and has made its implementation necessary. The main challenges of industrial managers in implementing a waste heat recovery plan, besides paying attention to climate and environmental issues, are reducing fuel consumption and dependence on electricity, as well as justifying the plan from an economic point of view. In the current research, the use of waste heat from the furnaces of the dehumidification unit of Bidbland Refinery is taken into consideration by sampling the combustion gases in a section of the chimney with a height of 11 meters and a diameter of 1.24 meters, in addition to the parameters required for environmental tests, waste energy It was also calculated from furnaces. The power generation process has been simulated with the help of the organic Rankine cycle in three designs: simple, superheated, and regenerative. In carrying out this simulation, it is assumed that the temperature of the input sources and the temperature of the output source are in a certain range, and are in the steady state. Finally, based on the thermodynamic and economic analysis, R142b fluid in the superheated and normal butane cycle and R245fa in the simple cycle are the main priorities used in the refinery pilot with a payback period of 2.63, 2.64 and 2.97 years, respectively.

In this study, at first the combined steam and organic Rankine cycles, have been stimulated with high-temperature wasted hot gases recovery, from the energy and exergoeconomic points of view. In the configuration of the combined cycles, the high-temperature wasted gases acts as the source of steam cycle evaporator, then the decreased temperature exhaust gas of the steam cycle evaporator, is used as the low temperature source of organic cycle evaporator. Afterward the effects of changing different parameters such as temperature of the evaporator and condenser of steam cycle and pinch temperature difference, on the amount of total output work, total irreversibility, energy efficiency, exergy efficiency and exergoeconomic variables have been checked. The results in base state show that, energy and exergy efficiency of combined cycles are 0.2782 and 0.5279 respectively and the amount of output work and total irreversibility are 71401kW and 43616kW respectively. Total exergoeconomic factor for the combined cycles is 12.47 percent, which represents a high exergy destruction in components and recommends raising the initial cost of components in order to improve the performance of system. The evaporator, turbine and condenser of steam cycle, are the components that should be considered from the perspective of the exergoeconomic, because they contains the maximum amount of total initial costs and the cost of exergy destruction.

In this work, Organic Rankine cycle with open feed heater and Trilateral Flash cycle are used for waste heat recovery of exhaust gas and cooling water of a 34.3 kW stationary gas engine. The thermodynamic and thermo-economic performance of the bottoming cycles have been investigated, and then sensitivity analysis and multi-objective optimization have been done considering the objective functions of exergy efficiency and the special investment cost of the cycles. The optimal point is selected based on the LINMAP method on the Pareto Front. The results show that the exergy destruction rates in the heater and condenser of the Trilateral Flash cycle and the evaporator of the organic Rankin cycle are more than those of other components. Among the decision variables, the turbines isentropic efficiency and the condenser temperature of Trilateral Flash cycle have a significant effect on the objective functions. Employing waste heat recovery system on a gas engine results in an increase of 6.09% of the exergy efficiency of the overall system, including gas engine and bottoming cycles in the optimized state.