A Novel Structure of Rolling Piston Type Rotary Compressor

This paper presents a new design of rolling piston type rotary compressor and the analysis of the performance of the novel compressor is conducted. The concept of the novel compressor is to utilize the interior space of the roller as inner working volume. The vane is connected and fixed to the outer cylinder and the inner cylinder, and the split bush is located between the roller and the vane to help revolution of the roller. Therefore, the novel compressor has two working volumes. One is outer volume trapped within the outer cylinder, the vane, and the roller and the other is inner volume trapped within the inner cylinder, the vane, and the roller. In the same frame size, the cooling capacity of the novel compressor is increased by average 34.77% over that of the traditional rolling piston type rotary compressor. This is because the mass flow rate of the refrigerant into the compressor increases due to the increase of the total working volume. However, the input power is also increased by average 23.4% over that of the traditional rolling piston type rotary compressor. It is because the indicated work increases due to inner compression work. As a result, the energy efficiency ratio (EER) of the novel compressor is increased by 9.42% over that of the traditional rolling piston type compressor

Numerical Investigation on Effects of Sub-cooling Methods on Performance of Multi-split Variable Refrigerant Flow Systems with Bypass and Vapor Injection Techniques

The pipeline connected between outdoor units and indoor units is lengthened in the VRF systems because the VRF systems are generally used in light commercial buildings. Therefore, a sub-cooler is installed in the VRF systems to avoid flash gas caused by pressure drop and heat transfer in the liquid pipeline. Usually, the liquid refrigerant in the pipeline can be cooled by bypass and refrigerant injection techniques with an internal heat exchanger (IHX) and electric expansion valve (EEV). In this study, the performance of the VRF systems using bypass and refrigerant injection cycles are compared by numerical method. The simulation for multi-split VRF is developed with considering application of vapor injection and bypass cycle and validated with experimental data. The bypass and refrigerant injection have improvement potential for cooling capacity by 3.11% and 15.5%, respectively due to increasing enthalpy difference in evaporators. The vapor injection technique has more improvement potential of performance than bypass technique. Subcooling degree at inlet of EEV is above 10°C degree in two systems, which can avoid flash gas generation

Tratamiento con aire previo a la degradaci´on anaer´obica de residuos s´olidos urbanos Estudio comparativo

Se estudi´o la variaci´on de cantidad y calidad de lixiviados producidos porresiduos s´olidos urbanos (RSU) en condiciones anaer´obicas sin estabilizaci´on previay con pretratamiento aer´obico, efectu´andose adem´as el estudio comparativo de laestabilidad alcanzada por las masas y reducci´on de vol´umenes.Los residuos fueron separados en dos fracciones iguales, deposit´andose una enun reactor anaer´obico y otra en un aer´obico hasta finalizar la etapa activa debiodegradaci´on, para tratarla luego anaer´obicamente.La calidad de lixiviados se estudi´o mediante el seguimiento de DBO, DQO,Conductividad, pH, Color, AOV, Alcalinidad, ST y STV. En residuos pretratadosse recolectaron menores cantidades de lixiviados.Se hall´o mayor grado de estabilizaci´on en los residuos pretratados, con 93 %de reducci´on de Materia Org´anica F´acilmente Oxidable y mayor disminuci´on devolumen. Existe una reducci´on estad´ısticamente significativa en DBO de los lixiviados hasta los 64 d´ıas de tratamiento, mientras que la reducci´on en DQO es muysignificativa hasta los 48 d´ıas

Track D Social Science, Human Rights and Political Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd