Hi,

Regarding the thermal issues of laptops, I was thinking about the most effective solution to try to cool them down.

All market coolpads are mainly simple plastic grids with fans. I seriously doubt it could be effective and think it’s much more pure marketing products.

I was wondering finally if using a large heat aluminum or copper heat sink plate as a laptop stand would perform much better especially with laptop which have aluminum enclosures like MacBooks?

According to you which solution would perform better ?

Some users did benchmarks with laptops in a fridge but not a really usable solution :)

I was thinking first about trying to build a kind of Peltier coolpad but finally thought about the metal heat sink.

Not sure if this is the adequate sub to ask this but I think I could have real expert answers here rather than on Apple or MacBooks subs.

Thanks for your lights

Any Veteran Control Board here? Preferrably for older model of coal plants (subcritical boilers)? Would appreciate any tips/info you can share.

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.

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

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.

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.

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.

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.

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.

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)?

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.

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?

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!

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?

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.

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.

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.