The key component of Compressed Air Energy Storage (CAES) system is an air compressor/expander. The roundtrip efficiency of this energy storage technology depends greatly on the efficiency of the air compressor/expander. There is a trade off between the thermal efficiency and power density of this component. Different ideas and approaches were introduced and studied in the previous works to imp...

Title of Dissertation: INVESTIGATION OF VAPOR INJECTION HEAT PUMP SYSTEM WITH A FLASH TANK UTILIZING R410A AND LOW-GWP REFRIGERANT R32 Xing Xu, Doctor of Philosophy, 2012 Dissertation Directed by: Professor Reinhard Radermacher Department of Mechanical Engineering Vapor injection technique has proven to be effective in improving heat pump system performance, especially for cooling application a...

Aiming at solving the problems of high compressor discharge temperature, pressure, insufficient cooling capacity, and reduced system efficiency in air-conditioning pure electric passenger cars summer temperature environment, this paper develops a low pressure economizer using principle quasi-two-stage compression cycle. The heat pump air conditioning air-supplemented car is set up to study its ...

Considering the high consumption of the air compressors, a control system of screw compressor is designed and implemented to deal with energy saving and localization of mentioned compressor. In this paper the variable speed drive (VSD) control algorithm based on proportional-integral-derivative (PID) controller is optimized to decrease power consumption and more stable motor speed and outlet pr...

This paper describes modeling and simulation of air compressor energy use to estimate energy savings in compressed air systems from air use reduction and other changes. The method uses measured power signatures and other compressor parameters as inputs to calculate various performance metrics and estimate energy savings. To enable recognition of control mode from measured power data, examples o...

In most of the Automotive Air Conditioning Systems (AACSs) though the compressor is powered by the car engine, the evaporator blower and the condenser fan are run by a 12-volt DC battery which is powered by an alternator. Any fault in the alternator, drops the battery output voltage. Owing to this, a stationary test rig for an AACS is developed with all actual automotive components. A continuou...

The operation of air-cooled chillers accounts for significant energy consumption in local commercial buildings, and low operational efficiency especially under partial load conditions and poor control are part of reasons for such huge energy consumption. Chiller efficiency can be improved by enhancing heat transfer rate in condensers. This paper considers how the chiller performance can be impr...