Abstract The need for energy is increasing worldwide as the population has a continuous trend of increase. restrictions on sources are becoming tougher authorities set these developed and developing countries. This leads to looking other alternative replace conventional sources, leading greenhouse emissions. Environmentally friendly (renewable energies), example, geothermal, solar wind, viewed ...

Mechanical subcooling systems, both dedicated and integrated, have attracted lot of attention in the recent years due to their great potential improve transcritical CO2 refrigeration systems. Numerous studies theoretically determined COP increments that these systems can offer compared classic experimental works evaluated optimum working conditions for each individual system. However, they not ...

The utilization of fluted inner tube in tube-in-tube heat exchangers is an effective way to improve the transfer performance. Based on segmented model, performance a gas cooler (FTGC) transcritical CO2 pump water heater was studied this paper. simulation model validated and adopted numerically investigate effects different parameters cooler, which compared smooth (STGC) with same geometric para...

This research focuses on the development of a unified drop vaporization model for use in simulations of high-pressure spray combustion processes. Emphasis is placed on the analysis of supercritical and transcritical processes. These processes occur when a liquid drop that is initially at a subcritical temperature is injected into a high-pressure gaseous environment that exceeds the thermodynami...

Defrosting is an important issue that should be considered when air source heat pump operating in a cold climate. For the transcritical CO2 (TCHP) water heater, high pressure affects application of defrosting methods. In this paper, reverse cycle (RCD) and hot gas bypass (HGBD) methods were experimentally investigated TCHP heater. The dynamic characteristics, influences on system operation over...

The air flow rate on the gas cooler side is one of key parameters affecting performance and running safety transcritical CO2 electric vehicle conditioning systems. After experimentally analyzing effects volume in cycle system performance, a novel method to evaluate optimal was proposed. In addition, effect (e.g., discharge pressure) explored. Finally, coupling compressor speed, ambient temperat...

This AUTO demo shows the use of a set of boundary conditions for the localization and continuation of the transcritical bifurcation of a limit cycle in a four-dimensional Marr-Pirt model.