Rankine cycle

1. RANKINE CYCLE A presentation by: AKASH SOOD For : MALWA Inst. of Tech. & Mgmt. Submitted to : Mechanical Deptt . A PART OF VAPOUR POWER CYCLE

2. CONTENTs Introduction and Defining Types of Cycles Ideal Rankine Cycle Reheat Rankine Cycle Regeneration Rankine Cycle Why we use Rankine Cycle? Conclusion Query A presentation by: AKASH SOOD

3. INTRODUCTION Who is Rankine and What is Rankine Cycle? A Scottish CIVIL ENGINEER, physicist and mathematician. He was a founding contributor, with Rudolf Clausius and William Thomson, to the science of thermodynamics, particularly focusing on the first of the three thermodynamic laws . The Rankine cycle is a cycle that converts heat into work. The heat is supplied externally to a closed loop, which usually uses water. This cycle generates about 90% of all electric power used throughout the world. William John Macquorn Rankine A presentation by: AKASH SOOD

4. TYPES OF CYCLES Ideal Rankine Cycle Re-heat Rankine Cycle Re-generation Rankine Cycle A presentation by: AKASH SOOD

5. BLOCK DIAGRAM OF RANKINE CYCLE Boiler Turbine Compressor (pump) Heat exchanger 1 2 3 4 Q out Q in W out W in A presentation by: AKASH SOOD

6. IDEAL RANKINE CYCLE In a real Rankine cycle, the compression by the pump and the expansion in the turbine are not ISENTROPIC . In other words, these processes are NON-REVERSIBLE and entropy is increased during the two processes. This somewhat increases the power required by the pump and decreases the power generated by the turbine. So , the other Engineer’s and Sir Rankine make it modify. A presentation by: AKASH SOOD

7. Energy analysis: steady flow process, no generation, neglect KE and PE changes for all four devices, 0 = (net heat transfer in) - (net work out) + (net energy flow in) 0 = ( q in - q out ) - ( W out - W in ) + ( h in - h out ) PROCESS: 1-2 : Pump (q=0)  W pump = h 2 - h 1 = v(P 2 -P 1 ) 2-3 : Boiler(W=0 )  q in = h 3 - h 2 3-4: Turbine(q=0 )  W out = h 3 - h 4 4-1: Condenser(W=0 )  q out = h 4 - h 1 Thermal efficiency h = W net / q in = 1 - q out / q in = 1 - (h 4 -h 1 )/(h 3 -h 2 ) W net = W out - W in = (h 3 -h 4 ) - (h 2 -h 1 ) T s

8. DEVELOPMENTS A presentation by: AKASH SOOD

9. RE-HEAT RANKINE CYCLE The optimal way of increasing the boiler pressure but not increase the moisture content in the exiting vapor is to reheat the vapor after it exits from a first-stage turbine and redirect this reheated vapor into a second turbine. boiler high-P turbine Low-P turbine pump condenser A presentation by: AKASH SOOD

10. T-S DIAGRAM T s high-P turbine low-P turbine boiler high-P turbine Low-P turbine pump condenser A presentation by: AKASH SOOD

11. Energy analysis: Heat transfer and work output both change q in = q primary + q reheat = (h 3 -h 2 ) + (h 5 -h 4 ) W out = W turbine1 + W turbine2 = ( h 3 -h 4 ) + (h 5 -h 6 ) Efficiency : : Work Done/Heat Supplied A presentation by: AKASH SOOD

12. RE-GENERATION RANKINE CYCLE Use regenerator to heat up the liquid ( feedwater ) leaving the pump before sending it to the boiler, therefore, increase the averaged temperature (efficiency as well) during heat addition in the boiler. T s 1 2 2’ 3 4 Lower temp heat addition T s 1 2 3 4 5 6 7 Use regenerator to heat up the feedwater higher temp heat addition Extract steam from turbine to provide heat source in the regenerator

13. T-S DIAGRAM Pump 2 Pump 1 Open FWH boiler condenser Open FWH T s

14. Energy analysis: Heat transfer and work output both change Energy analysis: q in = h 5 -h 4 , q out = (1-y)(h 7 -h 1 ), W turbine , out = (h 5 -h 6 ) + (1-y)(h 6 -h 7 ) W pump , in = (1-y)W pump1 + W pump2 = (1-y)(h 2 -h 1 ) + (h 4 -h 3 ) Efficiency : : Work Done/Heat Supplied In general, the more feedwater heaters, the better the cycle efficiency. A presentation by: AKASH SOOD

15. THANKS FOR WATCHING For further quarries contact : AKASH SOOD Branch : Mechanical Engineering IInd year (MITM, GWALIOR) or on FACEBOOK www.facebook/akku.sood or MAIL ME @ [email protected]