Table 1. Standard air density as a function of elevation above sea level (at 70F and 50% relative humidity). M echanical ventilation can be divided into three types: negative-, positive-, and neutral-pressure ventilation. Negativepressure systems use fans to exhaust air, thereby creating a slight partial vacuum that draws fresh air in from outdoors. Negative-pressure ventilation systems are use...

The temperature of exhaust gases from simple cycle gas turbine generation sets (GENSETs) is usually very high (around 500 C), and a heat recovery steam generator (HRSG) is often used to recover the energy from the exhaust gases and generate steam. The generated steams can be either used for many useful processes (heating, drying, separation etc.) or used back in the power generation system for ...

During extremely hot summer days, air conditioning systems are known as major electricity consumers in residential, commercial and industrial sectors. Moreover, high energy requirement of multiple-chiller plants may cause an interconnected power grid be faced with annual on-peak electrical demand, load-generation mismatch, voltage collapse and catastrophic wide area blackout. Therefore, this pa...

In conventional vapor compression systems, electronic expansion valves (EXVs) are used for refrigerant flow control. Subcooled refrigerant enters the expansion device and is expanded to the evaporation pressure while the valve opening is modified to achieve the desired mass flowrate. The relationship between the inlet and outlet conditions, the opening, and the mass flowrate has been extensivel...

In this study, artificial neural networks have been used to model the effects of four important parameters consist of the ratio of the length to diameter, the ratio of the cold outlet diameter to the tube diameter, inlet pressure, and cold mass fraction on the cooling performance of counter flow vortex tube. In this approach, experimental data have been used to train and validate the neural net...

this paper describes the theoretical and experimental investigations of the key components and also the performance analysis of a rotary wheel for using as a solid desiccant dehumidifier and also indirect evaporator cooling system. solid desiccants have long been used in dehumidification and cooling systems for energy efficiency or reduce electricity. although many mathematical models on the ro...

This paper presents a theoretical model and a numerical simulation of a liquid-gas two-phase flow within a microchannel (50 500 2 m m cm μ μ × × ) equipped with distributed liquid water injection through the side walls. The modeling and solution of the conservation equations provide pressure drop as a function of inlet velocity. The influence of different parameters involving water injection is...

To get comfortable air, it can be done by using an air conditioner or cooler. The electrical power used for the cooler is relatively lower. This research aims to see effect of number cooling pads on output condition and effectiveness was conducted experimentally. varying used, thick. distance between 1.5 cm. temperature inlet has a dry bulb 30

A standard air cooled data center is a rare phenomenon. Generally each one is individually designed, with hundreds of different component combinations. They can also be energy hogs. Cooling system power consumption in older data centers is typically 100% or more of the IT load. While energy efficiency has improved recently and Power Utilization Effectiveness (PUE) values – the ratio of total en...