Systems analysis for the development of small resource recovery systems: research and development needs. Final report

Simulation-based optimization of thermal systems

The improved industrial sample of the rotor-pulse heat generator (RPH), integrated into the thermal heating systems of industrial buildings, was produced. Rotor-pulse generators do not occupy significant positions in the market of heating equipment because of the lack of reliable data on effectiveness of the use of such equipment in the thermal heating systems of industrial facilities. The design of the developed cavitation chamber was changed, parameters of the channels, located between the rotor and the stator, were determined. It was found that the optimal width of the gap between the rotor and the stator channels at maximum efficiency of 0.7 was 8–10 mm. When integrating the cavitation chamber of the RPH into the thermal system, the design of the heat exchanger pipe-in-pipe was changed into the plate one. Bench tests of energy efficiency of the thermal system operation were conducted. Indicators of energy efficiency of the system with the improved RPH were determined, the analysis was performed by comparing with analogues, described in the literature. It was proved that improvement of the thermal system allowed obtaining the improved indicators of energy efficiency. Bench testing showed that efficiency of the improved thermal system is by ≈17 % higher than efficiency of thermal systems based on the multi-stage RPH. The automatic system of monitoring and control of the thermal system with the use of vibration-frequency sensors for assessment of cavitation process effectiveness was developed. The conducted commissioning works made it possible to determine the possibility of applying the developed automatic system with appropriate software for monitoring and control of the thermal system operation. The obtained data of comparative analysis allow recommending the developed rotor-pulse heat generator as a credible alternative to the used thermal devices in thermal heating systems of industrial buildings.

Progress and Prospects for Research and Technology Development of Supercritical CO2 Thermal Conversion Systems for Power, Energy Storage, and Waste Heat Recovery

Rapid energy flow calculation method for integrated electrical and thermal systems

Combined electrical MHD heat transfer thermal extrusion system using Maxwell fluid with radiative and viscous dissipation effects

Standard energy systems for individual dwellings nowadays are still mostly conventional in North America and other places. Heat generation for a larger part is commonly met by using mostly natural gas while the use of renewable energy systems to replace fossil fuels is starting to become widespread, especially in Alberta, Canada, which is an oil driven region. It is of interest to evaluate the seasonal performance of a hybrid thermal energy system at NAIT, which is being used to meet the heating needs of the lab space in the D building and aid for teaching purposes. Seasonal performance of a hybrid thermal energy system (geo-exchange, solar thermal energy systems and air source heat pumps) at NAIT, will help analyse and describe the concepts and the parameters affecting the design and optimization of a heat source hybrid energy system, identify key parameters to help determine the optimal design of individual component as part of a larger system; highlight year-to-year performance of the system and overall design and optimization. The average yearly and total generation of the evacuated tube solar collector was reported to be 7.84 kWhs and 2268.59 kWhs, respectively compared to 1.59 kWhs and 987.15 kWhs for the geo-exchange system and 0.42 kWhs and 108.76 kWhs, respectively for the flat plate solar collector. The evacuated tube solar collector shows an overall improvement of 94.53%, 95.89% and 95.96% compared to the flat plate solar collector for the year 2015 to 2017, respectively. Comparing the geo-exchange system and the flat plate solar collector, it can be seen that the geo-exchange system outperform the flat plate solar collector with an overall improvement of 42.87%, 61.32% and 67.51, respectively.

Optimize and analyze a large-scale grid-tied solar PV-powered SWRO system for sustainable water-energy nexus

Multi-objective design optimization of battery thermal management system for electric vehicles

The entropy generation analysis is an approach to optimize the performance ofdifferent thermal systems by investigating the related irreversibilities of the system. This paper provides a concise review of the entropy generation analysis performed for different solar thermal energy systems including solar collectors, solar heaters, solar heat exchangers, and solar stills. The mathematical formulation and the equations for calculating the entropy generation are briefly presented. Moreover, main passive techniques including the usage of nanofluids, porous materials, and inserts which are used to improve the efficiency of different solar systems are discussed. It is shown that using entropy generation minimization method is an efficient tool to find the optimaldesign of solar systems. The current review aims to motivate researchers in the field of solar energy for using entropy generation analysis to reduce the lost work and consequently improving the system performance.

While solar thermal power plants are increasingly gaining attention and have demonstrated their applications, extending electricity generation after the sunset using phase change material (PCM) still remains a grand challenge. Most of the organic PCMs are known to possess high energy density per unit volume, but low thermal conductivity, that necessitates the use of thermal conductivity enhancers (TCEs) to augment heat transfer within PCM. In this paper, thermal performance and optimization of shell and tube heat exchanger-based latent heat thermal energy storage system (LHTES) using fins as TCE for medium temperature (<300 °C) organic Rankine cycle (ORC)-based solar thermal plant are presented. A commercial grade organic PCM, A164 with melting temperature of 168.7 °C is filled in the shell side and heat transfer fluid (HTF), Hytherm 600 flows through the tubes. A three-dimensional numerical model using enthalpy technique is developed to study the solidification of PCM, with and without fin. Further, the effect of geometrical parameters of fin, such as fin thickness, fin height, and number of fin on the thermal performance of LHTES, is studied. It is found that fin thickness and number of fin play significant role on the solidification process of PCM. Finally, the optimum design of the fin geometry is determined by maximizing the combined objective of HTF outlet temperature and solid fraction of PCM at the end of the discharging period. The latent heat thermal storage system with 24 fins, each of 1 mm thickness and 7 mm height, is found to be the optimum design for the given set of operating parameters.

Energy saving in thermal energy systems using dimpled surface technology – A review on mechanisms and applications

Potential applications of inserts in solar thermal energy systems – A review to identify the gaps and frontier challenges

Optimization techniques that search a solution space without designer intervention are becoming important tools in the engineering design of many thermal fluid systems. Evolutionary algorithms are among the most robust of these optimization methods because the ability to optimize many designs simultaneously makes evolutionary algorithms less susceptible to premature convergence. However application of evolutionary algorithms to thermal and fluid systems described by high fidelity models (e.g. computational fluid dynamics) has been limited due to the high computational cost of the fitness evaluation. This paper presents a novel technique that combines two technologies used in the optimization of thermal fluids systems. The first is graph based evolutionary algorithms that are implemented to help increase the diversity of the evolving population of designs. The second is an algorithm utilizing a feed forward neural network that develops a stopping criterion for computational fluid dynamics solutions. This reduces the time required for each future evaluation in the evolutionary process and allows for more complex thermal fluids systems to be optimized. In the system examined here the overall reduction in computational time is approximately 8 times.

Thermo-economic analysis and comparative study of different thermally integrated pumped thermal electricity storage systems

For seeking out suitable means of thermal insulation system of building envelope in south China, this paper has conducted simulation analysis on respective energy consumption of the typical residential template in cold region and south China, when adopt exterior thermal insulation system or interior thermal insulation system. The study has shown that the exterior thermal insulation system is much better than the interior thermal insulation system in energy efficiency in the cold region, but there isn’t obvious difference between them in south China. And from the aspects of the climate’s influence on the insulation quality, the installation’s influence on the building facades and the construction practices, it is proved that the interior thermal insulation system is more suitable than the exterior thermal insulation system in south China.