Search results for "R41"
showing 9 items of 9 documents
On-site Experimental Study of HCFC-22 Substitution with HFCs Refrigerants
2012
Abstract The European Regulation no 2037/2000 has banned manufacturing HCFC refrigerants from January 1st 2010, although its use is allowed up to 2015 if the fluids come from a recycling process. This situation creates the need for developing new working fluids to replace the HCFC in the refrigeration plants now in operation. Among all the HCFCs the R22 is the most widely used in a wide range of applications, especially in air conditioning. This paper presents the results of an experimental analysis comparing the performance of a vapour compression refrigerating unit operating with R22, and its performance in comparison to some HFCs fluids, substituting the former. In particular, the plant …
Experimental performance evaluation of a vapour compression refrigerating plant when replacing R22 with alternative refrigerants
2011
Abstract This paper presents the results of an experimental analysis comparing the performance of a vapour compression refrigerating unit operating with R22, and its performance in comparison to a new HFC fluid, substituting the former according to Regulation No 2037/2000. In particular, the plant working efficiency was first tested with R22 and then with three new HFC fluids: R417A, R422A and R422D. The investigation verified that despite the case of substitution and the advantage of being able to continue to use mineral oil as a lubricant in the compressor, the performance with the new tested fluids did not result as efficient as when using R22.
Joint route planning under varying market conditions
2007
PurposeTo provide empirical evidence on the level of savings that can be attained by joint route planning and how these savings depend on specific market characteristics.Design/methodology/approachJoint route planning is a measure that companies can take to decrease the costs of their distribution activities. Essentially, this can either be achieved through horizontal cooperation or through outsourcing distribution to a logistics service provider. The synergy value is defined as the difference between distribution costs in the original situation where all entities perform their orders individually, and the costs of a system where all orders are collected and route schemes are set up simulta…
Quel rôle du réseau de voirie urbaine sur la distribution des flux piétonniers ?
2007
In the urban networks, the pedestrian frequency of streets is variable. At an aggregated level, it partially depends on the spatial configuration of the urban network. This concept, called the “natural movement”, is a key-notion in space syntax. It is here investigated by assuming several explanatory factors: metric accessibility, network linearity, route linearity, route continuity. Data obtained from a pedestrian movement survey in the city of Lille (France) were used. The factors were represented by series of theoretical frequencies defined with origin and destination points stemmed from real trips. These theoretical frequencies were compared to the observed pedestrian frequencies. The s…
Paysages et choix d'itinéraires pédestres en milieu urbain. Une nouvelle approche par les bifurcations
2007
Walking has long been neglected in urban mobility research. In the context of a sustainable mobility, it is now included into numerous works including various approaches. The well-known models of flows affectation are often used to study the behaviour of pedestrians and to identify their preferences. However, the factors that are usually chosen to describe the urban environment are usually limited or inappropriate to the pedestrian movement. In addition, these models assume that the choices made by pedestrians are predetermined at the start of each trip, without any possible decision intervening along these trips. In this paper, we propose to test the role of urban landscape by using a new …
An experimental study of a refrigerating plant when replacing R22 with HFCs refrigerants
2011
This paper presents the results of an experimental analysis comparing the performance of a vapour compression refrigerating unit operating with R22, and its performance in comparison to some HFCs fluids, substituting the former according to reg. n. 2037/2000. In particular, the plant working efficiency was first tested with R22 and then with three HFC fluids: R417A, R407C and R404A. The investigation verified that the performance with HFCs refrigerants did not result as efficient as when using R22. An environmental analysis also was performed.
La nodalité des gares TGV périphériques
2005
Several high speed train stations have been established recently on the outskirts of French urban areas in order to minimize travel time and enhance railway profitability. Even though they allow for interconnexions between several transportation modes, they seem to offer a much lower degree of nodality within the railway network than older central city stations. However, their nodal role should be gauged in terms of function rather than physical infrastructure. Relational capacities of the stations were estimated using topologic direct accessibility graphs and morphological nodality ratings. The network patterns of their rail links allow us to identify several kinds of stations according to…
Use of HFC fluids as suitable replacements in low-temperature refrigeration plants
2014
An experimental investigation of the performance of a low-temperature refrigerating unit working with R22 and a comparison of its performance when operating with replacement HFC fluids in accordance with the European Regulation CE-1005/2009 are presented in this paper. Plant working efficiency was tested with R22, as baseline, and then compared with four different HFC fluids: R413A, R417A, R422A and R422D. The refrigerating unit was a vapour-compression plant equipped with a reciprocating double-cylinder compressor able to keep the cold room at -20ºC. Lower values of the temperature at the end of compression and polytrophic exponent can be achieved with the HFC tested. Substituting the R22 …
Efeitos da sustentabilidade e valor logístico nas relações entre empresas de transporte marítimo
2020
Resumen El objetivo de este trabajo fue analizar cómo la sostenibilidad (económica, social y ambiental), bajo el enfoque de triple línea base, afecta la calidad de servicio, el valor logístico y la satisfacción en empresas del sector marítimo. Se propone un modelo teórico que se contrasta con la información suministrada por una muestra de 50 responsables de empresas (transitarios, importadores y exportadores) en Panamá. La información se analiza mediante la estimación de regresión por mínimos cuadrados parciales, que permite confirmar el carácter multidimensional de la sostenibilidad y del valor logístico. Los resultados también confirman que las percepciones de los clientes sobre las inici…