2.Gas Power Cycles
2.Gas power CyclesBITS PilaniDubai Campus
THE CARNOT CYCLE Heat engine operates on a cycle. The efficiency of heat engine depends on how theindividual processes are executed. The most efficient cycles are reversible cycles, that is,the processes that make up the cycle are all reversibleprocesses. Reversible cycles cannot be achieved in practice. However,they provide the upper limits on the performance of realcycles.2
The fundamental thermodynamic cycle proposed byFrench engineer Sadi Carnot in 1824, in an attempt toexplain the working of the steam engine. Carnot cycle is one of the best-known reversiblecycles. The Carnot cycle is composed of four reversibleprocesses.3
CARNOT CYCLE Consider an adiabatic piston-cylinder device that contains gas. The four reversible processes that make up the Carnot cycleare as follows: 1-2 Isothermal Expansions 2-3 Adiabatic expansions, 3-4 Isothermal compressions and 4-1 Adiabatic compressions.
: Figure : A Carnot cycle acting as a heat engine, illustrated on a temperature-entropydiagram. The cycle takes place between a hot reservoir at temperature TH and a coldreservoir at temperature TC. The vertical axis is temperature, the horizontal axis isentropy.
The Carnot Cycle (1-2): Reversible Isothermal Expansion6
The Carnot Cycle (2-3): Reversible Adiabatic Expansion7
The Carnot Cycle (3-4): Reversible Isothermal Compression8
The Carnot Cycle (4-1): Reversible Adiabatic Compression9
The Carnot principle The Carnot principle states that the reversible heat engines have the highestefficiencies when compared to irreversible heat engines working between the same tworeservoirs. And the efficiencies of all reversible heat engines are the same if they work betweenthe same two reservoirs. The efficiency of a reversible heat engine is independent on the working fluid used and its properties, The way the cycle operates, The type of the heat engine. The efficiency of a reversible heat engine is a function of the reservoirs'temperature only.10
ηth 1 - QL/QH g(TH,TL)orQH/QL f(TH,TL)WhereQL heattransferredtothelow-temperaturereservoir which has a temperature of TLQH raturetemperatureofTHg, f any function11
IDEAL OTTO CYCLE - IDEAL CYCLE FOR SPARK-IGNITION ENGINES Otto cycle is the ideal cycle for spark-ignitionengines, in honor of Nikolaus Otto, whoinvented it in 1867. In ideal Otto cycles, air-standard assumptionis used. The ideal Otto cycle consists of four internalreversible processes: 1-2 Isentropic compression 2-3 Constant volume heat addition 3-4 Isentropic expansion 4-1 Constant volume heat rejection12
Otto cycle is the ideal cycle for spark-ignition13
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Diesel Cycle - Ideal Cycle for Compression-ignition Engines27
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efficiencies when compared to irreversible heat engines working between the same two reservoirs. And the efficiencies of all reversible heat engines are the same if they work between the same two reservoirs. The efficiency of a reversible heat engine is independent on the working fluid used and its properties,
Evaluate the performance of gas power cycles for which the working fluid remains a gas throughout the entire cycle. Develop simplifying assumptions applicable to gas power cycles. Review the operation of reciprocating engines. Analyze both closed and open gas power cycles. Solve problems based on the Otto, Diesel, Stirling, and
existence of life cycles in various applications, e.g., life cycles of scholars and research topics (academia), life cycles of consumers and merchandises (on-line business) etc. Despite the significance of it, collaborative filtering with life cycles is highly challenging, as summarized below. Life Cycle versus Wall Time: Users and items may .
Studies in Business Cycles 1 Business Cycles: The Problem and Its Setting By Wesley C. Mitchell 2 Measuring Business Cycles By Arthur F. Burns and Wesley C. Mitchell 3 A merican Transportation in Prosperity and Depression By Thor Hultgren 4 Inventories and Business Cycles, with Special Re
KitName Catalog# HiSeqSBSKitv4(250cycles) FC-401-4003 HiSeqSBS Kitv4(50cycles) FC-410-4002 . Cycles Index1 (i7)Read Cycles Index2 (i5)Read Cycles Read2 Cycles Total Cycles Single-Read, Non-Indexed . S. Illumina *20000451* HiSeq 2500 System Guide (15035786)
A pipeline can process n tasks in k n -1 cycles k cycles are needed to complete the first task n -1 cycles are needed to complete the remaining n -1 tasks Ideal speedup of a k-stage pipeline over serial execution Pipeline Performance Pipelined execution in cycles k n -1 Serial execution in cycles S k k for large n nk S k
4 1. technical data 1.1 air distribution (normal operation) 1.3 defrost cycles table 1.2 air distribution (defrost mode) vf0054 vf0055 outside temperature defrost cycles (minutes)extended defrost cycles (minutes) celcius ( c) fahrenheit ( f) defrosting operation time between each defrost cycles defrosting operation time between each defrost cycles-5 23 9 60 10 30-15 5 9 32 10 20
COMBINED GAS–VAPOR POWER CYCLES The continued quest for higher thermal efficiencies has resulted in rather innovative modifications to conventional power plants. A popular modification involves a gas power cycle topping a vapor power cycle, which is called the combined gas–vapor cycle, or just the combined cycle.
LP gas - 1.53 specific gravity Required Gas Supply Pressure (to gas train) 6" WC minimum (std) 4.5" WC minimum (special) Input Voltage ** 120 Vac 10% / -15%; 60 Hz Input Current 5.3 Amp Gas Train 24V Valves High/Low gas pressure switch Life Cycle Gas valves are rated for 100-000 cycles (regarding valve seat leakage). Application Type
