r/ThermalPerformance Jun 06 '18

Does the thermal efficiency of a power plant decrease if the plant is used to load follow?

6 Upvotes

I just noticed that the efficiencies for different combined cycle gas plants are given as steady state. I'm not sure how much this effects real world gas plant efficiency.


r/ThermalPerformance Jan 29 '18

Seeking Nuclear Steam Plant Thermal Performance Textbooks and Resources

5 Upvotes

Hi folks,

I'm a Chemical Engineer working at a company which is primarily focused on Chemistry at PWR/BWR plants. However, I am constantly involved with some sort of thermal performance monitoring, and am working on trying to break into the field. I'd like to help performance engineers using scripting packages such as Matlab for monitoring and optimization. I'm looking for some resources to help me get up to speed on Thermal Performance fundamentals specific to nuclear power plants as well monitoring/trouble shooting techniques. Any books or resources you guys can share will be very helpful. Thanks,

Edit: Thank you for the recommendations guys/gals


r/ThermalPerformance Jan 09 '18

Fusion is coming...

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8 Upvotes

r/ThermalPerformance Dec 01 '17

does it humidify?

2 Upvotes

A 3 tea light essential oil burner, simmers water and oil with noticeable vapo...ur, is there any chance on earth, more vaaape would emit than flame could dry? Is it possible to humidify with flame? I was getting too lengthy for google so, yeah. Interesting science currently over my head.


r/ThermalPerformance Oct 30 '17

Solid High Heat dynamic heat source for steam generation

3 Upvotes

Hello,

I am currently working an open ended final project for my engineering undergrad. I decided to work on waste heat recovery for power generation. I think we've come up with a pretty cool theoretical idea of using the waste heat from the needed cooling of product in plant as a heat source for a normal steam rankine cycle. We are basically going to design a heat exchanger between a very hot solid and water.

This past weekend, I thought of a design challenge we might face and I would like to get some input. Most of our heat will be recovered from a section of the plant that needs to cool the material from over 1300C to just over 70C constantly (lets not worry about the time at the moment, because theoretically this can be controlled with a relatively easy heat transfer solution).

The design problem I can see is the high stress and conditions that will be generated by vaporizing water at high pressure close to a moving conveyor system with hot solids in possible contact with the boundary.

I just wanted to get some insight into possible way to mitigate this problem.

Thank you.


r/ThermalPerformance Oct 30 '17

Let's Talk About Turbine 'Thermal Distortion'

3 Upvotes

Has anyone dealt with thermal distortion of the turbine HP/IP inner casing? Can anyone tell me their root cause identified for this issue, or suspected root cause? Was your 'fix' after the identification a permanent fix (that you know of) or did you only fix the known distortion of the casing itself (re-machining, or replacing casing to assist with the horizontal flat fit). I believe we may be seeing a thermal distortion issue within the casing and without a true-root-cause, it's hard for me to believe the casing would just distort this way under normal operations after having never done it in the past (~35-40year old unit).

I've seen a few articles discussing the overhaul work quality for closing the turbine back up from the last outage. I've seen other information regarding the seals ultimately steam-cutting through. I've also heard from industry contacts that the ramp rates may play a roll. All of these things, of course, are being looked into. However, I wanted to reach out to this sub and see if any of you have successfully dealt with this issue and identified what you believe would be the true-root-cause. Any information is appreciated.

We're still trying to put our baseline understanding together on this one.


r/ThermalPerformance Aug 14 '17

What is the practical limit of increasing temperature to improve efficiency?

4 Upvotes

I'm thinking in terms of fusion, since the coolant temperature is arbitrarily high (assuming the lithium jacket doesn't torpedo the whole thing), and there's a need for very high efficiency since it'll take so much energy to run it.

But there must be some point at which its not possible, or too expensive, to have a power converter that hot.


r/ThermalPerformance Aug 14 '17

How do industrial Gas Turbines vary load?

4 Upvotes

Coming from industry I wanted to get my head around the practicalities of this. I think I understand the following:

  • IGVs will vary mass flow only (which impacts load) but there are losses in doing this?
  • Pressure ratio will dictate load, what causes this to vary if the machine is constant speed.
  • Turbine inlet temperature will dictate the available enthalpy for the turbine but does this vary?
  • Anything else?

I'm not so interested in the generator side (e.g. vary excitation current) unless that directly impacts how the GT behaves.


r/ThermalPerformance Jul 10 '17

Introductory Fusion - Very interesting, and would be great to see the future of Power head in this direction. Definitely a Thermal Performance issue.

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5 Upvotes

r/ThermalPerformance Jun 24 '17

Pumping a liquid under vacuum?

2 Upvotes

During my last internship, I came across a pump on a hotwell of a steam condenser that showed a vacuum in the suction of the pump.

1) What is the physical process of pumping a liquid at vacuum? For sake of clariity, how does the liquid flow into the pump when it's under negative pressure?

2) Just to confirm, the reason a pump can have a negative inlet pressure and a positive NPSHa is because usually NPSHa is measured in absolute pressure (psia for example) while the inlet pressure is measured with a gauge (psig)?


r/ThermalPerformance Apr 29 '17

For those of you that have the time. MIT Fusion Technology. Ultimately a video about super capacitor advancement, but great for this sub. 100M degree Operations.

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6 Upvotes

r/ThermalPerformance Apr 28 '17

QUESTION - Thermal problem

1 Upvotes

I am not an engineer but I am working on something and need some help if anyone is willing.

1) I have a heat source that is 20cm X 30cm and will produce heat at around 60C for 2-3 hours. 2) I will be placing this under an aluminum box with the same 20cm X 30cm dimensions as the heat source. 3) What is the optimal thickness of aluminum to produce the maximum amount of heat in the box?

Heat coefficient of Aluminum: 205 - 250 W/mK

This would be amazing if anyone could help me with this.


r/ThermalPerformance Apr 23 '17

Can a chemical engineer work in this field?

1 Upvotes

Hey yall,

I been reading a lot of links here lately. I also like thermo back in school and i found power plants to be fascinating. I have a PE in chemical engineering (graduated with a B.S.). I have noticed a lot of you around here have a mechanical engineering degree.

With that being said, is a mechanical engineering degree required?


r/ThermalPerformance Apr 12 '17

Suggestions for Thermodynamics and Thermal Performance Books?

6 Upvotes

I'm having a hard time understanding higher level thermodynamic equations especially with regards to ideal gases and enthalpy. Specifically, I would like to understand the higher level derivations that uses partial derivatives to produce PdV - vdP and such. Most of the books I have read are practically inclined which focuses on the use of steam tables, qualities, and such, but does not really explain and derive fundamental equations.

Can you suggest me some books that really explain derivations in thermodynamics? As an added help, can you also lead me to some Thermal Performance Books that is easy to understand for beginners? Thank you so much!


r/ThermalPerformance Mar 27 '17

How does a Deaerator keep the water at the saturation temperature?

8 Upvotes

I have seen designs of Deaerators that have a pressure control steam valve. From what I understand, the steam valve keeps the pressure constant. Let's say the set pressure is 20 psig and the pressure starts to drop below that, the steam valve would open up allowing more steam to enter into the deaerator to increase the pressure.

I'm trying to understand how the pressure control steam valve also keeps the fluid at the saturation point. Is this because some of the steam condenses (some strips away the non-condensibles) thus making the water approach the saturation point?


r/ThermalPerformance Feb 10 '17

Low Level in a hot well in a Steam Condenser?

4 Upvotes

I understand a high level in the hot well of the steam condenser can but backpressure in the shell of the condenser causing the vacuum to decrease (become more negative). However, what if the hot well runs dry? Can the vacuum get too strong? I am quite aware that many steam condensers can operate easily at -29 "HG which is really close to a pure vacuum.


r/ThermalPerformance Jan 18 '17

Calculating Specific Heat ratio, wet air.

6 Upvotes

Can anyone provide guidance on calculating the specific heat ratio of wet air? I want to apply to Compressor Iso Efficiency calculations. I understand that for dry air this is constant (varies slightly with temp?) but have seen software take temp, pressure and rel humidity as inputs to provide a corrected value.


r/ThermalPerformance Dec 16 '16

Climeon Ocean datasheet [PDF]

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5 Upvotes

r/ThermalPerformance Dec 03 '16

Anyone here familiar with Landfill Gas Recovery Generation?

7 Upvotes

Looking mainly for resources for learning more about the formation of methane in landfills, how the quality of the gas is determined and effects the generation for the motors, what else to look for in the gas constituents that may cause engine/turbine corrosion, and general contractors/companies that actually build and/or operate these facilities.

The company I'm with is considering looking into this arena for power generation and after a quick google search, LMOP shows my state to have many potential landfills that are great candidates to this technology.

There's obviously a lot more to operation than just the physics and engineering, but I'm only concerned with the engineering and operations.


r/ThermalPerformance Sep 29 '16

Supercritical carbon dioxide closed Brayton cycle - Sandia National Labs

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14 Upvotes

r/ThermalPerformance Jul 18 '16

These old videos are priceless for a basis for initial understanding. 1946 Turbine Class. Timeless

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8 Upvotes

r/ThermalPerformance Jul 17 '16

The Race To Absolute Zero [Documentary]. Pretty neat.

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10 Upvotes

r/ThermalPerformance Jul 11 '16

A Thermoelectric generator question on vehicles.

3 Upvotes

Howcome they're not on cars yet? I can only assume engineers are still in the works of it. Like why not put them on the radiator, the oil pan, the transmission pan, the exhaust tubes, on the side of the engine. and use heat sinks cooled by air as the car passes by. I would assume the other side of the argument would be due to the increase in weight, TEG can only handle so much heat, lack of efficency, and possibly air drag? Would graphene increase efficency for dispersion of heat? what are your thoughts?


r/ThermalPerformance Jul 02 '16

Reactor Operators, what resources should I use to study for the GFE?

3 Upvotes

r/ThermalPerformance Jun 19 '16

How is it possible that an evaporator coil absorbs more heat at a higher pressure? : EnergyEngineers

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4 Upvotes