جستجوی مقالات مرتبط با کلیدواژه "refrigeration" در نشریات گروه "مواد و متالورژی"
تکرار جستجوی کلیدواژه «refrigeration» در نشریات گروه «فنی و مهندسی»جستجوی refrigeration در مقالات مجلات علمی
-
In the present work, the performances of improved two-stage multi inter-cooler trans- critical carbon dioxide (CO2) refrigeration cycles with ejector and internal heat exchanger have been examined. In the new improved cycles, an internal heat exchanger is append to the cycles. Also, second inter-cooler in improved cycles, cooled with the refrigeration of the cycle, so that in first cycle it is a branch of saturated vapour flow from separator and in second cycle it is a branch of supersaturated steam from internal heat exchanger as well. Results are validated against those available in the literature. Comparisons of the results indicate that there is an excellent agreement between them. The influences of important operational parameters in the cycle performance such as pressure of gas-cooler, temperature of evaporator and temperature of gas-cooler on the performance of cycle have been analysed. The obtained results present that if the cooling flow for second inter-cooler supply from saturated vapour from separator, maximum coefficient of performance can be improved 25% in comparison with the conventional cycle at the considered specific states for operation.Keywords: Trans-critical, refrigeration, Carbon dioxide, multi inter-cooler, internal heat exchanger
-
This study embraces a steady numerical simulation of thermodynamic model optimized for an ammonia-water diffusion absorption refrigeration (DAR) cycle with hydrogen or helium as the auxiliary gas. A DAR cycle has been examined due to the fact that such cycles may operate under low cooling load without a mechanical pump. To this end an Electrolux refrigerator manufactured by Dometic of Sweden is examined. The generator of this system has been modified to have it coupled with a parabolic trough collector in order to enhance the heat transferred to the generator. Besides, considering temperature range gained by the collector, the DAR cycle has been optimized. Finally, the results are validated against available experiments. It was found that the effects of parameters such as generator temperature, ammonia solution concentration, pressure of the cycle and the temperature of the main components of the cycle can change the COP by ±10% .Keywords: Ammonia water, Solar Energy, Diffusion Absorption system, Refrigeration, COP
-
The paper presents study the factors that can improve the performance of an activated carbon/methanol intermittent solar adsorption icemarker. That uses an adsorption tube collector for cooling, in which solar energy can be directly absorbed. Effect of some important parameters, such as amount 8of methanol, condenser temperat., initial and peak collector temperat., on the system performances were investigated. The amount of activated carbon is fixed and is equal to (4 kg) for all the experiments that have been performed. Several quantities of Methanol were tested (650 g, 750g, 900g) to get the best system performance. The experimental test rig of present work was designed to produce 2 kg of ice by using Activated Carbon in a concentration of 0.28 kg Methanol/kg Activated Carbon. The shape of the flat plate type adsorber/collector was parallelogram with dimensions (110 cm× 67 cm×8 cm). The results show that the coefficient of performance of the unit decreases with increase the condenser and evaporator temperat.. The new in this paper that the maximum average of COP was 0.49 but the minimum was 0.4 that agree with literat. experiments in this field.Keywords: Adsorption, Refrigeration, Active carbon, Methanol
نکته
- نتایج بر اساس تاریخ انتشار مرتب شدهاند.
- کلیدواژه مورد نظر شما تنها در فیلد کلیدواژگان مقالات جستجو شدهاست. به منظور حذف نتایج غیر مرتبط، جستجو تنها در مقالات مجلاتی انجام شده که با مجله ماخذ هم موضوع هستند.
- در صورتی که میخواهید جستجو را در همه موضوعات و با شرایط دیگر تکرار کنید به صفحه جستجوی پیشرفته مجلات مراجعه کنید.