new to a HVAC environment!! PUZZLED.what to do

[mushtash]

i am a recent graduate of mechanical engineering and i recently got a job in a international complex housing shopping malls and executive offices.i am deputed to a chiller plant room.though i know the basics of an absorption system,the very sight of a plant room seems too FRIGHTENING..all so much integrated..pumps,chillers,,chemical dosing pumps,headers,,bypassess,,controls,,sensors,,discharge lines going to the service areas such as office buildings,,shopping malls etc...how to go about this dilemma?how and where should i start?changing which parameters alters the operations of the whole system?...etc...any suggestions of how to break things down into categories?..more about simplifying things .....need sound advice..thank you

 

[cdxx139]

start with the asbuilt drawings and look through the O&M's if available. Asbuilt control sequences would be invaluable too

knowledge is power

 

[KiwiMace]

Make coffee for the guys that do know.

 

[mushtash]

whats the difference between a schematic and an as-built drawing? how and in what way does an asbuilt drawing help?

 

[cdxx139]

"As built" is the record drawing you get from the contractor at the end of the project. It is the map of how and what was built and where. And usually different from the contract documents, which the engineer designed, but wasnt actually built that way.

If you have a schematic, then that is better for what you are looking for right now. Study it, it will help you understand the plant on a system basis.

knowledge is power

 

[mushtash]

what do we mean by the terms control philosophy, design philosophy and operation scheme?

 

[sspeare]

Get the ASHRAE handbooks. Also learn about primary/secondary loop piping concepts with Dan Holohan's books.

 

[mushtash]

thank you all for your enlightening posts..sspeare.DAN HOLOHAN's book ''Pumping Away and other really cool piping options for hydronic systems''.is related to heating systems whereas i am concerned more with chilled systems.

 

[willard3]

Water is used in both heating and cooling systems and, luckily, it acts pretty much the same.

 

[Falah7582]

Take it easy, I recommend you first not to freak out then take each unit alone and do simple search and go to basics as in real life not all what you studied has to be there its much simpler.
Do mistakes and learn from it, and don't worry too much all problems has solutions even complex problems has simple solution for it.

 

[mushtash]

is there any change in the temperature when the water goes from the suction of a centrifugal pump to the discharge?

 

[cjw81]

Forget about the handbooks, this gentleman is in above his head. His HR department has placed a mechanical engineer in a Stationary Engineer's position. You should inform them before someone get's hurt. Mechanical design and operations two totally different fields.

 

[willard3]

Find an Engineer to mentor you, you will never become an Engineer asking random questions on a web forum.

Also, read board policies here:

http://www.eng-tips.com/faqs.cfm?fid=376

 

[MechEngNCPE]

You are in way over your head. Do not change setpoints on anything - do not touch anything - seriously you can endanger a lot of people. Just find someone who knows what they are doing and ask if you can follow them around everywhere and ask a bunch of questions. I repeat - Do not touch anything.

 

[urgross]

Sounds like Borat is working on a comedy about engineers.

 

[ProcessHVAC]

I agree, this is an operator's job, not an engineer's job.

 

[urgross]

Or an engineer with experience, not a cherry. Better a chiller plant than a boiler or a cryo plant. It's actually difficult to get a refigerant leak. I'm still guessing it's a Sasha Baron Cohen set up for a goof on engineers.

 

[Shophound]

A plant operator can certainly understand concepts of engineering. I'm involved with chiller and boiler plant operations daily and I know my way around the equipment, a pyschrometric chart, water chemistry, essential thermodynamics, etc.

Why one who says he holds a degree in engineering feels frightened to death by the practical application of engineering (a chiller and boiler plant) is beyond me.

To the OP, I got your email, as did one of my colleagues in the HVAC field, saying the same thing you posted above. You come across that way as someone firing arrows at random, hoping to hit the target by sheer luck. If you feel frightened by a central plant, either your school did you no favors by moving you along regardless of your performance, or you had a lot of difficulty grasping what was taught, or at the very least you have difficulty making those teachings apply in a practical fashion. Something ain't right. Maybe it's me...but understand the way I look at it is that the guys who designed my central plant probably also have degrees in mechanical engineering, whereas I do not. They're the ones who SHOULD know how it works just as well as I do, if not more so.

 

[Stella84]

Hi,

I am an Engineer with 2 years of experience in HVAC manufacturing (AHU, Energy Recovery units...). I recently joined an EPC company which is involved in oil & Gas industry. I would like to know if there's any references, books or any document that can help me with HVAC design in Oil & Gas industry.

I undrestand that I have to deal with different departments such as civil, architecture, controls, electrical and automation, loss and prevention...My knowledge of manufacturing only helps me with TBE (technical Bid Evaluation) where I have to review the submittal documents from vendors.

I am passionately wanting to learn more about HVAC design in oil & gas industry and any help from any of you would be greatly appreciated.

Thanks!

Stella

 

[MTES93]

I see the intent of this forum to help, so I will offer what I can.

In terms of where to go to learn this STUFF. I agree w/ above on ASHRAE handbooks and whoever mentioned Dan Holihan is genius. For hydronic or steam basics this guy is the a guru. Not only in technical expertise but in delivery. And keep in mind Dan, to the best of my knowledge is NOT an engineer. Early in my career I was taught some of the most important lessons in this field by non-engineers. I am one but I NEVER doubt a good control guy or mechanical contractor ever. My philosophy is to shut up and listen. Make judgements/decisions later.

Start w/ the hydronics portion(s).... pipes, pumps... valves and related. ASHRAE Systems and Equipment will give you a great snap shot to start w/. As to your question if you can get heat gain thru a centrifugal pump. Absolutely. Its called mechanically inefficiency or better known as an irreversibility in thermodynamic terms. A normal pump motor will be 85 to 92 percent efficient while a pump's mechanical efficiency can range all over the map from 55 to 75 percent (way worse on small buggers)... Thus a 70% mechanical efficient pump will dump 30% of the shaft horsepower as heat into the loop. Ain't a mystery... It's just science.

I agree not to touch any control setpoints until you understand the systems. You can really mess stuff up if you get too deep into to stuff and mess with it. I know, cuz I have. Partial knowledge is worse than NO knowledge as my dad used to say.

As-builts versus schematics... Somebody above hit the nail on the head. A schematic is what I do in an attempt to design something.... An as-built would be something the contractor puts together to show ... as it sounds the AS-BUILT system. Normally they don't mess too much w/ flow diagrams/schematics stuff as that is normally process orientated and what the engineer's concept is and it better work. An as built is more of the contractor showing actual routing of ducts/pipes, equipment placement and related. If one of my flow diagrams or process diagrams has been 'red-lined' or 'as-builted' excessively then I pretty much hosed up.

Is your control system a direct digital control type or at least have a temperature control's contractor's name tag somewhere... like Johnson Controls... Andover, Alerton... Siemens.... I dunno who you have. Find out a local office and have their application or field people come in and teach you how the system works.. You may have to pay them but it would be absolutely worth it!

Hope this helps.