Reduce surface area of air cooled heat exchanger (it mean downgrade?)

[RyuDK]

I am project engineer of one of EPC company.
During the project I raise one technical query to COMPANY(Owner) regarding optimization of air cooled heat exchanger size but they simply rejected.
So I want share this situation and hear the opinion from you.

Below is my understanding.
----------------
1) Thermal design for air coolers shall be done in accordance with licensor's process data, project
standards and specifications under EPC Contractor's responsibility.

2) Pipe rack width and limited plot area should be considered in thermal design through optimized air side
design as well as tube side.

3) Construction data from thermal design by licensor during FEED stage is deemed to be preliminary for estimation purposes,
thus all construction data shall be finalized by EPC contractor during detail engineering phase.

4) Construction data of tube side will be variable according to air side design in air coolers and also it will be
different from vendor to vendor.

5) Therefore, tube side design including surface area may be adjusted by contractor in condition of keeping
all process parameters such as heat duty, flow rate, in/out temp, etc. and all requirements on specifications.

PROPOSED SOLUTION:
Air coolers will be specified with duty and other operating parameters (Flow rates, Temperature and design
requirements) as per licensor data sheet. Detail design and area requirement for all air coolers will be
optimized as per vendor design according to Project Specification.
----------------

So during the detail engineering we discussed many vendor's, as a result they submitted quotation with reduced surface area air cooled heat exchanger.
I though if I can maintain the performance for example duty and other operating parameters (Flow rates, Temperature and design
requirements), reduced size is not issue. But Company deemed to it as downgrade refer to below clause.
"equipment size/capacity/duty or material shall, regardless of any statement implying or indicating the contrary, be considered as
the minimum requirements for developing the detailed engineering design, performance and fabrication."

Actually reduced size of air cooled heat exchangers are our proposal basis.
So if we increase size, it will occur big effect not only the size of air cooler but also plot size, pipe rack too.

I want hear your opinion.
What is the general practice and best practice, is there any chance to keep my opinion?

 

[TD2K]

< What is the general practice and best practice >

That's not the question here nor is it going to help you. At this point, you have a conflict between the various clauses and terms in the basis for the project, not uncommon.

You're going to need to go through the proposal documents and bid documents and see where you stand on what clauses take precedent. If your bid was based on realizing that the air coolers (as one example) could be downsized and give the same thermal performance, did you put anything in your bid taking exception to requirements of the bid documents?

 

[IRstuff]

Where did they specify the size? Are you on contract? What does the contract say? The contract has precedence over anything else, barring illegality. What was in your original proposal? Many contracts make the proposal a binding document.

TTFN
faq731-376

Need help writing a question or understanding a reply? forum1529

Of course I can. I can do anything. I can do absolutely anything. I'm an expert!

 

[MintJulep]

Sounds like you have a a poor specification, and a client that doesn't understand engineering and treats the spec as THE SPEC the same as THE BIBLE.

Nothing you can do.

 

[racookpe1978]

Your project will fail if the "physics" of the heat exchange will not work in the "physical world" ! As stated above, regardless of the "specifications" of the paper (the contract), the project will fail if the heat exchange time of operation (duty cycle), temperature of the incoming air, relative humidity, air flow, delta temperature 9inlet to outlet) and heat exchange coefficients, etc, etc, etc are not sufficient to transfer enough energy in a short enough time.

Your contract only tells you if you will be paid and at what rate for what kind of performance of the heat exchanger. It will NOT tell you how the heat exchanger will actually operate under what kind of conditions.

If the physics of the heat exchanger will not work (the equations show you need to change something (like adding air flow by adding a fan or increasing heat exchange area by adding pipes or changing flow rates or lengthening the duty cycle) then you MUST change something to make the physics work.