Topic
Thermal expansion valve
About: Thermal expansion valve is a research topic. Over the lifetime, 14054 publications have been published within this topic receiving 87586 citations.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: Experiments confirmed that like in a conventional transcritical R744 system with expansion valve, the high-side pressure control integrated into the ejector could be used to maximize the system performance.
Abstract: This study presents experimental results obtained from a transcritical R744 system using a refrigerant ejector. The results were compared to that of a conventional system with an expansion valve. For the test conditions considered, the cooling capacity and COP simultaneously improved by up to 8% and 7%, respectively. Experiments were analyzed to quantitatively assess the effects on system performance as a result of changes in basic ejector dimensions such as motive nozzle and diffuser sizing. Small angles of 5° yielded best results for the static pressure recovery of the high-speed two-phase flow entering the diffuser. Experiments confirmed that like in a conventional transcritical R744 system with expansion valve, the high-side pressure control integrated into the ejector could be used to maximize the system performance. Numerical simulation results helped identifying this basic trend. Due to difficulties in the ejector throat pressure measurements, a more practical performance metric was introduced in order to quantify overall ejector efficiencies. According to this definition, the prototype ejector was able to recover up to 14.5% of the throttling losses.
348 citations
••
TL;DR: In this paper, an ejector expansion transcritical CO2 refrigeration cycle was proposed to improve the COP of the basic CO2 cycle by reducing the expansion process losses and a constant pressure mixing model for the ejector was established to perform the thermodynamic analysis.
Abstract: An ejector expansion transcritical CO2 refrigeration cycle is proposed to improve the COP of the basic transcritical CO2 cycle by reducing the expansion process losses. A constant pressure mixing model for the ejector was established to perform the thermodynamic analysis of the ejector expansion transcritical CO2 cycle. The effect of the entrainment ratio and the pressure drop in the receiving section of the ejector on the relative performance of the ejector expansion transcritical CO2 cycle was investigated for typical air conditioning operation conditions. The effect of different operating conditions on the relative performance of the ejector expansion transcritical CO2 cycle was also investigated using assumed values for the entrainment ratio and pressure drop in the receiving section of the ejector. It was found that the COP of the ejector expansion transcritical CO2 cycle can be improved by more than 16% over the basic transcritical CO2 cycle for typical air conditioning operation conditions.
323 citations
•
23 Sep 2004
TL;DR: In this article, a drying apparatus for drying articles such as clothing is provided, which includes a chamber for containing articles to be dried and a system for supplying heated dry air at a first temperature to the chamber.
Abstract: A drying apparatus for drying articles such as clothing is provided. The drying apparatus includes a chamber for containing articles to be dried and a system for supplying heated dry air at a first temperature to the chamber. The air supplying system comprises an air flow pathway having an evaporator for removing moisture from air exiting the chamber and for decreasing the temperature of the air to below dew point temperature. The air supply system further has a condenser for increasing the temperature of the air exiting the evaporator to the first temperature. The drying apparatus further has a heat pump system having a refrigerant loop which includes a compressor, the condenser, a TEV valve, and the evaporator.
239 citations
•
12 Jun 2003
TL;DR: In this article, a system controller is used to control a subsystem having one of the compressor, condenser, valve, refrigeration branch, and case of a case adapted to be cooled by the evaporator coil, and a subsystem controller in communication with the system controller.
Abstract: A refrigeration system including a compressor, condenser, valve, and refrigeration branch, all of which is in fluid communication. The refrigeration branch includes an evaporator coil. The refrigeration system further includes a case adapted to be cooled by the evaporator coil, and a system controller operable to control one or more aspects of the refrigeration system, and a subsystem controller in communication with the system controller. The subsystem controller is operable to control a subsystem having one of the compressor, condenser, valve, refrigeration branch, and case. The method of operating the refrigeration system includes at the subsystem controller, monitoring a parameter of the subsystem, comparing the monitored parameter with a parameter limit, generating an alarm when the parameter is not within the parameter limit, and communicating the alarm to the system controller.
233 citations
••
TL;DR: In this article, the authors describe a theoretical analysis of a transcritical CO2 ejector expansion refrigeration cycle (EERC) which uses an ejector as the main expansion device instead of an expansion valve.
217 citations