Evaluate the performance of a typical two stage air compressor. An air compressor is a device that converts power using an electric motor, diesel or gasoline engine, etc. Intake or induction piston moves from tdc to bdc intake valve opens and air induced into cylinder pressure p1 and temperature t1 remain constant. The air enters each stage of the compressor at 300k and each stage of the turbine at 1200 k. The piston in each cylinder was then linked to separate dynamometer with each dynamometer having its own electrical variable speed drive located in the control panel. The first stage presents a pressure gauge and air filter too.
Air behaves like the ideal gas and follows the laws. The gas then goes to the second stage compressor, exiting at t4 and p4. Read here to know about the basics of compressing air and appreciate the reason for air compressor following polytropic or isentropic compression instead of isothermal or adiabatic one. Pdf numerical simulation study of a two stage reciprocating. The pressure ratio across each stage of the compressor and turbine is 3. The computer controlled twostage compressor test unit, hcdec, is a unit that. Fad is the amount of air handled delivered by the compressor. Thermodynamics ii chapter 3 compressors faculty of mechanical. Chapter 9 gas power cycles universiti tenaga nasional. In a singlestage compressor, the air is compressed one time. A numerical simulation of a twostage reciprocating compressor has. A natural gas mixture is compressed using a threestage centrifugal compressor. Air compressors machines thermodynamics engineering.
Figure 2 shows the layout of a two stage reciprocating compressor typically for supplying a workshop. The first stage compressor brings the gas to t2, p2. Is human sentence parsing a onestage or twostage process, two stage compressor an experiment was set to investigate the operation of the twostage air compressor the prime objectives of the experiment included to find the first hand experience of operation for the two stage intercooled compressed air and the associated equipment, 4 pages words lab report stage 1. Estimate the pressure ratio in various stages so as to minimize the total work input during compression. A twostage reciprocating air compressor is required to deliver 0. The gas exiting the second stage goes though another heatrejecting cooler and then into the compressed air tank 2. During the expansion work will be done by the fluid to drive, for example, electric generation. Two stage electric simplex part number hp model tank gal. Assuming that the process is isentropic and air is of ideal gas, the equation for.
Taking this phrase literally, the natural assumption is that 1,000 actual cubic feet per minute of compressed air is leaving the discharge of the compressor at 100 psig. The single compressor can be replaced by 2 compressors and a hex, called an. Thermodynamics ii chapter 3 compressors mohsin mohd sies fakulti kejuruteraan mekanikal, universiti teknologi malaysia. Find the temperature at the end of the compression and calculate per pound of air, the compressor work input and the heat rejected during compression. Compressor is the device which is used to compress the fluid and increase its pressure. Application of basic thermodynamics to compressor cycle. This cooled air is passed to the intermediate stage where it is again getting compressed and heated. After the engine is running for a sufficient time approx. Lower air receiver 4 upper air receiver 5 discharge to the lower air receiver which opens when the air pressure. By one of several methods, an air compressor forces more and more air into a storage tank, increasing the pressure.
Introduction a compressor is a mechanical device that takes atmospheric air and increases its pressure to generate thrust in industrial plants. Compressor efficiency an overview sciencedirect topics. Calculate the required power per stage by either equation 11 or 12. Oil lubricated air compressor 160 for multi stage 200 for single stage pure oxygen and pure chlorine 120 dry cylinder with teflon seals 200 other typical standard give maximum temperatur e 150 c for any gas based on adiabatic process. The inlet state is at p1 1 bar and t1 300 k, and the final exit. After each stage the compressed air is cooled back to the initial temperature t i.
If you define unsurpassed performance by maximum operating pressure, increased air flow and extended duty cycles, count on an ingersoll rand reciprocating air compressor to deliver it reliably. Compressor efficiency, regardless of the type of compressor, can best be understood by referring to a typical mollier diagram as depicted in fig. Thermodynamic analysis of gas compressor 1 similarly perfect aftercooling makes the gas, leaving. Multistage compressor an overview sciencedirect topics. It is defined as the ratio of volume of air before compression to the. In an air compressor, air is compressed by pulling in atmospheric air, reducing its volume and increasing its pressure. A multistage compressor is one in which there are several cylinders of different diameters. Sometimes the two compression stages are completely separate devices, as shown in my schematic, and sometimes they are really one big device with two compression stages driven by the same rotating shaft. Twostage and multistage air compressors bright hub. School of engineering technology mete123 thermodynamics air compressor experiment objective. Et 500 includes a complete compressed air generation system with a twostage compressor and an additional pressure vessel as intercooler. Two stage compressor lab report example topics and well.
Fig3 shows the arrangement of a single stage reciprocating air compressor, together with a typical indicator diagram. Performance assessment of a twostage reciprocating air. Application of basic thermodynamics to compressor cycle analysis r. Procedure the compressor used in this experiment is an integersolrand type 30 two stage air compressor. Pdf historically, the move toward multistage compression systems in.
Compression intake valve closes and piston moves towards tdc compression follows the polytropic process pvnc until p2 is reached. It is the quantity of air actually delivered by a compressor in m 3 minute or m 3 sec. A multi stage compressor is one in which there are several cylinders of different diameters. Define and calculate the interstage pressures for multiple compressors. Keywords thermodynamic analysis, single stage reciprocating compressor, volumetric efficiency. The diagram below shows the layout of a two stage reciprocating compressor typically. The diagram below shows the layout of a two stage reciprocating compressor typically for supplying a workshop. You will study the principles of reciprocating compressors in detail and some principles of rotary compressors. Mod01 lec12 thermodynamics of compressors nptelhrd.
The gas is then fed to an intercooler at constant pressure, which lowers the temperature to t3. Applied thermodynamics tutorial 2 gas compressors in order to complete this tutorial you should be familiar with gas laws and polytropic gas processes. Consider an ideal gasturbine cycle with two stages of compression and two stages of expansion. Twostage compressors can include two cylinder designs. Extremely reliable and economic compressor design detailed descriptions and information on the hg7 basic compressor can be found in the chapter entitled series hgha singlestage compressors starting on page 32. It is compressed in accord to the law and delivers it to receiver at 140psi. An air compressor takes in air at 14 psi and at 20 degrees c. Therefore, the highpressure air leaving the compressor. Most of the heat of compression is removed as the compressed air then passes through the intercooler to the second stage, where it is compressed to final pressure. For each stage, the measured pressure, and temperature are presented in table 1. For the thermodynamics modeling of power consumption of compressors, we. Minutes of the proceedings of the institution of civil engineers, volume 98, issue 1889, 1 jan 1889 254279 a new form of extensometer. Performance of a two stage reciprocating air compressor 1 abstract the experiment aims at studying the performance of a 2stage reciprocating air compressor and determining some or all of the following. In a multistage compressor, air is being compressed from pressure p i to a very high pressure p f.
Compressed air generation systems are used to drive machines in mining, for pneumatic control systems in assembly plants or tyre inflation systems at petrol stations. A twostage air compressor compresses the pressurized air a second time so the pressurized air being used will have double the pressure for double the efficiency and power. Some air compressor vendors often improperly use acfm. Performance of a two stage reciprocating air compressor. For example, an air compressor vendor may state that a 200 hp air compressor is rated for 1,000 acfm at 100 psig. Isothermal and volumetric efficiencies, energy balance, effect of intermediate pressure, effect of intercooling and comparison of the performance of the machine. Single stage compressor, equation for work inputcycle without clearance volume.
Pressures bourdon tube gauges 1 first stage discharge 2 second stage discharge 3valves open. These two stage compressors also deliver more reliability, less moisture buildup in the tank, and require less maintenance because the air is allowed to cool for longer. Evaluate the performance of a typical twostage air compressor. Thermodynamics ii chapter 5 refrigeration mohsin mohd sies fakulti kejuruteraan mekanikal, universiti teknologi malaysia. The free air has some density or the given mass of gas occupies certain volume in free space. This can be generalized to more than two stages z number of. Pdf on jan 1, 2004, m elhaj and others published numerical simulation study of a two. For multistage machines, this efficiency has a clear physical meaning. The percusyevick theory and the equation of state of the 6. When the tanks pressure reaches its engineered upper limit, the air compressor shuts off.
Stage 2 begins the compression stroke of the engine with the closing of the intake valve. Single and twostage reciprocating air compressors high. An ideal twostage air compressor has an intercooler between the two stages as shown below. The main difference between single and twostage compressors is the number of times that air gets compressed between the inlet valve and the tool nozzle. Data were also analysed using various appropriate compressor equations and a thermodynamic analysis of the compressor was done to. Forsthoffer, in forsthoffers more best practices for rotating equipment, 2017. First generation compression technologies consisted of reciprocating compressors, but. An infinitely small compression leads to state functions variations dp, dt, dh and ds. Between stage 2 and stage 3, the piston moves back into the cylinder, the gas volume decreases, and the pressure increases because work is done on the gas by the piston. Compression follows the polytropic process pv nc until p. Stage 3 is the beginning of the combustion of the fuelair mixture. The process within a twostage compressor alternately referred to as a dualstage compressor is similar to that of a singlestage, but with one variation. Turbine and compressor thermodynamics for engineer. In the twostage compressor, air is drawn in from the atmosphere and compressed to an intermediate pressure in the first stage.
Now well restart the compressor for the two steps required to complete the cycle. It is defined as the ratio of volume of air before compression to the volume of air after compression. Doc two stage air compressor stelio antonas academia. Derivation of work required to drive the single stage reciprocating air compressor. Compressed air is used for many purposes, including. T2 lab report lab t2 twostage air compressor student. Theoretical and experimental investigation of a single. Procedure the compressor used in this experiment is an integersolrand type 30 twostage air compressor. Can someone guide me how to formulate a multiple stage compressor in terms of intake air mass flow rate, specific work of each stage and other parameters. The intake of air in the first stage gets compressed and then it is passed over a cooler to achieve a temperature very close to ambient air. All produced heads shown on performance curves isothermal, isentropic, and polytropic represent the. Applications where air is taken for granted ingersoll rand single and two stage reciprocating air compressors are an ideal choice for applications that demand a reliable air supply for everyday use, but where running an air compressor ranks a distant second to running your business.
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