Yu Y.,EReIE |
11th IIR Gustav Lorentzen Conference on Natural Refrigerants: Natural Refrigerants and Environmental Protection, GL 2014 | Year: 2014
This paper is based on the study performed for AHRTI (The Air-Conditioning, Heating and Refrigeration Technology Institute) on joining techniques assessment. The purpose of this research program is to develop a guideline to minimize refrigerant leaks by using high-performance joints to ensure that designs and products are adequate to provide a leak-tight system. Sealing technologies of commonly used components (such as solenoid valves, service valves, flare fittings, filters, TXVs, sight glasses, etc.) of airconditioning and refrigeration industry have been identified in detail. Leak flow rates of those joints have been determined using the method of concentration measurement by infrared spectrophotometry in atest chamber with high testing accuracy. A large number of tests have been performed to investigate the leakage level of these components. Measurement of valves before and after manipulations, influence of torques, and leak tightness of pressure relief valves after pressure relief have been studied as well. Results show that if components are well chosen and properly mounted, the leak flow rates of refrigeration systems can be as low as some few grams/year, but several components are, by design, very sensitive to improper mounting or require torque wrench.
Pan X.,EReIE |
Clodic D.,EReIE |
Toubassy J.,CEP ParisTech
Greenhouse Gases: Science and Technology | Year: 2013
CO2 capture by antisublimation consists in cooling the fl ue gases down to the freezing temperature of CO2 and frosting CO2 on a low temperature heat exchanger surface at a temperature range defi ned by the CO2 concentration in the fl ue gases and the CO2 capture effi ciency. CO2 is then defrosted and recovered in a liquid state. This CO2 capture process by antisublimation is called AnSU®. The CO2 frosting temperature in fl ue gases is much lower than the triple point of water and therefore before CO2 capture, water contained in fl ue gases is removed to reach high purity CO2. This paper presents an overview of the antisublimation process and a brief review of test benches that have been set up in laboratory and on industry sites for validation and optimization of the antisublimation process dating back to the fi rst one constructed in 2003. Energy consumption and cost penalty of CO2 capture by antisublimation are evaluated for a coal-fi red power plant. A technical and economic analysis has been made and compared to CO2 capture by oxycombustion for a cement plant. Those two processes can be seen as cryogenics options and the detailed comparison gives insight into where energy losses take place and which capture process could be most adapted depending on specifi cations of the cement industry. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd.
Riva M.,MINES ParisTech |
Campestrini M.,MINES ParisTech |
Toubassy J.,EReIE |
Clodic D.,EReIE |
Stringari P.,MINES ParisTech
Industrial and Engineering Chemistry Research | Year: 2014
Design and optimization of cryogenic technologies for biogas upgrading require accurate determination of freeze-out boundaries. In cryogenic upgrading processes involving dry ice formation, accurate predictions of solid-liquid, solid-vapor, and solid -liquid-vapor equilibria are fundamental for a correct design of the heat exchanger surface in order to achieve the desired biomethane purity. Moreover, the liquefied biogas production process, particularly interesting for cryogenic upgrading processes due to the low temperature of the obtained biomethane, requires an accurate knowledge of carbon dioxide solubility in liquid methane to avoid solid deposition. The present work compares two different approaches for representing solid-liquid, solid -vapor, and solid-liquid-vapor equilibria for the CH4-CO2 mixture. Model parameters have been regressed in order to optimize the representation of phase equilibrium at low temperatures, with particular emphasis to the equilibria involving a solid phase. Furthermore, the extended bibliographic research allows determining the regions where more accurate data are needed. © 2014 American Chemical Society.