scholarly journals Analysis of energy efficiency of air handling unit with integrated air to air heat exchanger in heating mode

2020 ◽  
Vol 207 ◽  
pp. 01002
Author(s):  
Slav Valchev ◽  
Ivan Mihaylov
Keyword(s):  
Energy Efficiency ◽  
Heat Exchanger ◽  
Experimental Determination ◽  
Mass Flow ◽  
Coefficient Of Performance ◽  
Supply Side ◽  
High Effectiveness ◽  
Air Handling Unit ◽  
Heating Mode

Object of the present study is an experimental determination of energy efficiency parameters of air handling unit with integrated air to air heat exchanger: effectiveness of air to air heat exchanger, coefficient of performance and specific fan power of air handling unit. A daily performance of air handling unit is conducted. Effectiveness of supply side of air to air heat exchanger in range of 42.4 % to 52.5 % is received. Coefficient of performance in range of 1.50 to 2.08 and specific fan power of air handling unit in range of 1.39 kW/(m3/s) to 2.08 kW/(m3/s) are received. It was found experimentally that effectiveness of air to air heat exchanger depends on values of mass flow of supply and the exhaust air. High values of mass flow of the exhaust air responds to high effectiveness of supply side of air to air heat exchanger.

The Determination of Mass Flow in the Vapour-Compression Refrigerator

1935 ◽  
Vol 129 (1) ◽  
pp. 477-505 ◽  
Author(s):  
E. C. Smith
Keyword(s):  
Experimental Determination ◽  
Mass Flow ◽  
The State ◽  
Volumetric Efficiency ◽  
Coefficient Of Performance ◽  
Flow Meter ◽  
Wide Range ◽  
Liquid Portion ◽  
Vapour Compression

The paper describes an experimental determination of the mass flow of refrigerant per minute and refrigerating effect per minute in a vapour-compression refrigerator, when the state of the refrigerant at the exit from the evaporator was varied over a wide range of superheat temperatures and dryness fractions. The usual methods of measuring the flow of liquids in pipes were not suitable for the present work and a special type of flow meter, described in the text, was developed. The results obtained were not as theory would tend to suggest, but were substantially modified by practical conditions, particularly for dryness fractions between 0·97 and 0·87. The volumetric efficiency changed abruptly over this range from a higher to a lower value. The reduction was attributed to the effect of re-evaporation of. the liquid portion of the refrigerant in the compressor during the suction stroke, as it was found that the higher volumetric efficiency was obtained when the refrigerant was superheated throughout most of the delivery stroke, and the lower volumetric efficiency occurred when the state of the refrigerant on entering the compressor resulted in liquid being present in the cylinder at the end of the delivery stroke. The reduction in the volumetric efficiency resulted in a corresponding reduction in the mass flow, the refrigerating effect, and the heat rejected by the condenser per minute, and in the coefficient of performance for dryness fractions ranging between 0·97 and 0·87.

scholarly journals Energy efficiency of different bus subsystems in Belgrade public transport

2015 ◽  
Vol 19 (6) ◽  
pp. 2233-2244
Author(s):  
Slobodan Misanovic ◽  
Zlatomir Zivanovic ◽  
Slaven Tica
Keyword(s):  
Energy Efficiency ◽  
Simulation Model ◽  
Experimental Determination ◽  
Public Transport ◽  
Drive System ◽  
Theoretical Simulation ◽  
Driving Cycles ◽  
Electric Bus

Research in this paper comprised experimental determination of energy efficiency of different bus subsystems (diesel bus, trolleybus and fully electric bus) on chosen public transport route in Belgrade. Experimental measuring of energy efficiency of each bus type has been done based on the analysis of parameters of vehicle driving cycles between stops. Results of this analysis were basis for development of theoretical simulation model of energy efficiency. The model was latter compared with the results of simulation done by "Solaris bus & Coach" company for the chosen electric bus route. Based on demonstrated simulation, characteristics of electric bus batteries were defined, the method and dynamic of their recharge was suggested, as well as choice for other aggregates for drive system and technical characteristics for the electric buses were suggested.

scholarly journals Experimental determination of compressor map of the DGEN 380 engine compressor using the WESTT CS/BV turbine engine simulator

2021 ◽  
Author(s):  
Marek Orkisz ◽  
Karolina Pazura
Keyword(s):  
Experimental Determination ◽  
Mass Flow ◽  
Experimental Work ◽  
Rotational Speed ◽  
Pressure Ratio ◽  
Turbine Engine ◽  
Engine Compressor ◽  
Compressor Map ◽  
To Receive

Currently aviation focuses mainlly on increasing the economy and ecology of engines. Production of NOx, CO2 and SO adversaly impacts the environment. Parallel goal to minimize SFC to achieve both lower: emission and mission costs. The optimization of components is thus very important. One of the ways of optimizing cycle is doing that based on compressor maps. However it is very expensive to plot one since experimental work needs to be done. The aim of this article is to present a methodology of creating compressor map based on ENGINE ANALOGY. There was used the virtual bench WESTT CS/BV for tests to receive pressure ratio and mass flow of DGEN 380 for three different values of flight speed and altitude, while the rotational speed was changed. The construction similarity of CFM 56-5B and APS 3200 gives the opportunity to plotted compressor maps using the engine analogy without the need for an experiment or using the virtual bench.

scholarly journals EXPRESS ESTIMATION OF THE ENERGY EFFICIENCY OF A CENTRIFUGAL PUMP WITHOUT EXPERIMENTAL DETERMINATION OF ITS EXPENSES

2019 ◽  
pp. 46-52
Author(s):  
V. S. Kostyshyn ◽  
P. M. Nykolyn
Keyword(s):  
Energy Efficiency ◽  
Experimental Determination ◽  
Centrifugal Pump ◽  
Operating Mode ◽  
Total Efficiency ◽  
Operating Characteristics ◽  
Hydraulic Machines ◽  
Calculated Load ◽  
Load Angle

Using a mathematical model, created on the basis of the electrohydraulic analogy method, a methodology for express estimation of the energy efficiency of a centrifugal pump was developed. The design load angle for analyzing the efficiency of operating modes of hydraulic machines is determined. The dependence of the power-driven engine shaft and the total efficiency of the centrifugal pump on its calculated load angle is established. The relationship between load angle and speed coefficient, which is a prototype of an electromagnetic load angle which characterizes the synchronous machine operating mode, is determined. It is established the dependence of the main pump head on the calculated load angle and the differential pressure created by the centrifugal pump. The developed methodology makes it possible to avoid significant technical and financial difficulties, since flow meters have a high cost and certain requirements for installation, while manometers are established by the standard requirements of the technological process. The estimated value of the load angle of the centrifugal pump through its catalog parameters is determined. The operating characteristics for the main centrifugal pump of type НМ-7000-210 were calculated and built without experimental determination of its head. Such approach showed a good coincidence of calculated and experimental characteristics. Relative error of energy characteristics does not exceed ten percents.  The proposed methodology can be used for express estimation of the efficiency of energy transformations of the whole electric drive pump unit. Express-analysis is a key to successful management of the energy economy through timely detection of inefficient modes of operation of electric-driven pump units and makes energy research cheaper.

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