Control-Oriented Modeling of Transcritical Vapor Compression Systems

Theoretical Analysis of Transcritical Carbon Dioxide Vapor Compression Cycle

In the transcritical carbon dioxide vapor compression cycle heat is rejected in a gas cooler at supercritical pressure. At supercritical heat rejection the refrigerant temperature and pressure are independent on each other and one of the most important parameters affect on cycle performance is the pressure on the heat rejection side called the high pressure. A theoretical analysis shows the eff...

Using Carbon Dioxide in a Transcritical Vapor Compression Refrigeration Cycle

For most of the last fifty years, refrigeration and heat pump systems have been based on cycles using a fluorocarbon as the working fluid. Hovvever, with the discovery that fluorocarbons may have a profoundly detrimental effect on the earth ·s atmosphere. it has become necessary to find a suitable replacement for a fluorocarbon based refrigeration cycle. Such a replacement must perform comparab...

Steady State Modeling of Advanced Vapor Compression Systems

The use of heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems is always increasing. This is because the HVACR systems are necessary for food production and ability to inhabit buildings that otherwise would be inhabitable. Thus, there is continued research focused on improving the efficiency and reducing the negative environmental impact of these systems. The basic vapor ...

Dynamic Modeling And Control of Single and Multi-Evaporator Subcritical Vapor Compression Systems

Extremum Seeking Control for Energy Optimization of Vapor Compression Systems

In this paper, an energy optimizing extremum seeking controller is developed for vapor compression systems (VCS) that automatically discovers sets of inputs that minimizes the energy consumption while the machine is in operation. This controller optimizes an input-output map (from VCS inputs to electrical energy consumed) in realtime, and without relying on a model of the dynamics of a vapor co...