Trantham_M4.3

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Course: Thermal Measurements Lab Section: Module 4 Instructor Name: Dr. Pashayi Name(s): Carlton Trantham __________________________________________________________________________ Title : In this lab, we analyzed steam generator pressure and flow, as we isolated portions of the steam generator header. __________________________________________________________________________ Abstract: The flow rate of steam leaving a steam generator is dependent on downstream header pressure. When that header pressure is altered, steam flow leaving the generator will be immediately affected. This is fundamentally important as plant operators should understand the plant response to various operations like isolating portions of a steam generator header. __________________________________________________________________________ Introduction: When isolating the upper header of the steam generator pressure, we noticed an immediate increase in flow through the lower header. The steam flow through the lower header was likely limited by the area of the pipe as steam flow never increased above 7,200 KLBH. We made the same observation again when re-performing this on the second steam generator. Both steam generators work in tandem to maintain steam pressure to the HP turbine, and when flow through one generator is reduced, flow through the other will increase to compensate. __________________________________________________________________________ Methods: Open the simulator and launch “Lesson 02 - IC002 100 MOL”. You will then run the simulator and select MSR1. After allowing some time for stabilization, you will record all four steam generator pressures and steam flows, along with generator power. You will then convert all of the generator pressures into absolute pressure, and use the saturated steam table to convert the pressures into steam temperature. Next, you will shut HV-14 by selecting the valve and then selecting close.

Allow time for the plant to stabilize, and rerecord all the initial parameters we measured. When all the values are recorded, we are then going to shut HV-20 by selecting the valve, and then selecting close. When the valve indicates shut, allow sufficient time for the parameters to stabilize and rerecord all parameters measured a final time. ________________________________________________________________________ Results: 8. a. 4482.4 KLBH b. 1038.5 psig c. 4482.5 KLBH d. 1038.5 psig e. 4496.9 KLBH f. 1038.6 psig g. 4496.9 KLBH h. 1038.6 KLBH i. 17,958.6 KLBH j. 1408.8 MW 9. a. 551 F b. 551 F c. 551 F d. 551 F 10. Steam flow from the steam generators is based on downstream plant pressure. Both generators are sized to pass the same amount of steam at the same pressure in a parallel arrangement, therefore, if downstream is the same, steam flow out of both generators will be the same. If the steam flow from both generators is the same, the pressure within both generators will also be the same. Then since we calculate the temperature of the saturated steam based on the generator pressure, the temperatures will also match for the two generators. 14. Steam flow through SG-1 upper isolation has stopped completely, and its pressure has increased slightly. Steam flow through SG-1 lower isolation has increased significantly to compensate. The pressure is also lower in that header. Steam flow through SG-2 has increased to

compensate for the loss of steam pressure from SG-1, and its pressure has been reduced as a result. Overall generator power has also decreased. 15. a. 0 KLBH b. 1079.8 psig c. 7200 KLBH d. 1043.3 psig e. 4645.0 KLBH f. 1018.4 psig g. 4645.0 KLBH h. 1018.4 KLBH i. 16,490.0 KLBH j. 1398.7 MW 18. a. 0 KLBH b. 1,062.5 psig c. 7200 KLBH d. 1023.0 psig e. 0 KLBH f. 1023.1 psig g. 7200 KLBH h. 1062.8 KLBH i. 14400.0 KLBH j. 1383.5 MW The jumps come from the sudden drops in pressure due to our shutting of the steam generator header isolations. Steam flow through the unisolated headers will rise to compensate for the loss in pressure within the other header. 19. They are all header drain valves that lead directly to the condenser. If they were open at power, steam would be directly exhausted into the condenser without passing through the HP turbine. 20. They are bypass valves that allow you to equalize the pressure across the steam generator header isolation valves when they are shut, which makes them significantly easier to open. 21. Yes, as shown in our last simulation, if all steam flow from either of the generators will cause a reactor scram to prevent uneven cooling of the core based on the difference in the two hot and cold leg temperatures. 22. For this system to be isenthalpic, the boundaries would have to be the header between the steam generator and the HP turbine. If you included the steam generator, heat would be added and thus not be an isenthalpic process. If the turbine was included, work would be done by the fluid, and again not an isenthalpic process. There will be some throttling through the headers which is where the irreversible energy conversion occurs. 23. Again, if the valves themselves are analyzed as a system, they would each be an isenthalpic process when they opened. If you included the steam generators or the HP turbine in the system, it would no longer be considered isenthalpic. _________________________________________________________________________ Discussion : We observed the flow through both generators decrease when their upper headers were isolated. Other outside factors within the plant could have been changed to ensure generator power did not

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decrease when the upper or lower header was isolated. Raising primary plant flow through the generator, or raising the average coolant temperature would have raised the amount of available heat inside the generator and subsequently raised its pressure, minimizing the effect of the isolation. It is also vital to set up very specific boundaries when analyzing a system for any type of thermodynamic process. If your boundary is confusing or misunderstood, you will not be able to properly discuss what your system is based on its properties. For example, in this lab, if you weren’t specific when defining your system, you would never see that there are small isenthalpic processes that occur within the Main and Reheat steam systems. You may only look at the system as a whole, and see some components add heat, or extract enthalpy in the form of work. Both of those processes are not defined in an isenthalpic process. __________________________________________________________________________ Conclusion: Steam generator pressure and flow are dependent on downstream header pressure. When the header pressure is altered for any reason, there will be a direct impact on the generators. As operators, we must understand this process to ensure we never operate the plant in a way that could lead to damage based on our lack of understanding of these effects. __________________________________________________________________________ References: 3 Key Student, (n.d.) PWR Simulator. https://www.3keystudent.com/ Engineering Fundamentals, (n.d.). Saturated Steam Table. https://www.efunda.com/materials/water/steamtable_sat.cfm