Solution chemistry of wastes from US atomic weapons production is controlled to inhibit corrosion of carbon steel tanks used in containment and storage. The pH, nitrate ion and nitrite ion concentrations of fresh solutions are maintained within specified limits for this purpose. In the start up process for a new waste evaporator (RHLWE), non-radioactive solutions of similar chemistry will be ci...

The performance of a falling-film evaporator trial plant during the first year after installation at the CG Smith Sugar Illovo mill is described. Operating under conditions similar to those experienced in the mill's raw house first effectevaporator, the unit confirmed most of the reported characteristics of this type of plant and proved easy to operate. Problems experienced were associated most...

Abstract The performance of a dual evaporator cycle using ejector is compared with conventional employing pressure reducing valve. In both the systems, high temperature considered as flooded evaporator, thus separator employed after evaporator. However, low kind dry comparison i.e., and assisted, done for same cooling capacities dryness fraction at exit R134a, R152a, R1234yf refrigerants. effec...

An experimental and analytical study on the performance of carbon dioxide heat pumps for water heating was conducted. The performance of compact, microchannel, water-coupled gas coolers, evaporator, and suction line heat exchanger (SLHX) were evaluated in an experimental facility. Analytical heat exchanger models accounting for the flow orientation and changing CO2 thermophysical properties wer...

This paper presents a steady-state model that is useful for predicting the performance of centrifugal liquid chillers over a wide range of operating conditions. The model employs an elemental NTU-E methodology to model both the shell-and-tube condenser and the flooded evaporator. The approach allows the change in heat transfer coefficients throughout the heat exchangers to be accounted for, the...

The analysis of controllability of a heat exchanger operating under two-phase conditions is performed. An evaporator operating in a vapor compression system is chosen for the analysis. A moving-boundary model is used to simulate the dynamic behavior of the evaporator. First, the controllability of the linearized model is verified. Then, it is shown that the nonlinear model can be classified as ...

The paper presents the results of a theoretical stability analysis on a vertical type natural circulation heat recovery steam generator. The evaporator of the boiler consists of four parallel horizontal tube paths, which are connected at both ends with headers. For different operation pressures and geometries the dynamic instability and in particular the density wave oscillation (DWO) was analy...

Due to the dependence of boiling heat transfer rate on heat flux, saturation pressure, mass flux and refrigerant quality, efforts made to increase heat transfer rate often cause further drop in refrigerant saturation pressure. In this study, entropy generation mechanisms associated with two-phase flow in smooth evaporator tube subject to constant surface heat flux are investigated. Refrigerant ...

Automotive air conditioning (AAC) system with a variable displacement compressor (VDC) sometimes tends to experience hunting problems, where the system undergoes oscillation. The purpose of this paper is to study the hunting phenomena in this system and to find out the factors to cause the system stability by experimental investigation. In this paper, the test bench and testing method are descr...

Several samples of evaporator scale collected during the 1993 and 1994 milling seasons were analysed using x-ray diffraction, x-ray fluorescence, scanning electron microscopy and optical microscopy. The results were evaluated in terms ofcurrent knowledgeofevaporator foulingand similar trends were found to those published in the literature. From these results, typical evaporator scale profiles c...