Computational Fluid Dynamics (CFD) has now become a critical part of fired heater evaluation, particularly for revamps. However, even though the use of CFD is now common, there is no industry standard procurement process or scope definition methodology. The result is that the very tool being used to reduce technical risk for your project now introduces schedule and scope risk. In industry, a decent percentage of CFD projects infamously drag on well past the anticipated completion dates with no end in sight. For example, in one of the past projects I was involved in, the contract negotiations lasted 13 months and the project moved forward without the CFD simulation, finally suffering in getting approval from the end user. Ensuring better upfront communication and supplying the few key pieces of information outlined below, you can start your CFD project off in the right way, resulting in receiving higher quality bids, knowing your deliverables, and reducing project schedule risk.
Typically, a project manager solicits bids for CFD simulation pricing using a brief description in an email. The CFD simulation vendor then requests some additional preliminary information such as general arrangement drawings, heater data sheets, operating conditions and the objective of the study. The project manager then collects this information over a span of a week or two and sends it to the CFD vendor. A proposal is put together by the vendor with estimates of cost and schedule. This process, while it works, is inefficient.
It would be more efficient if the project manager compiled a packet of information described below prior to submitting the Request for Proposal (RFP):
A one-page summary document describing the equipment, and the problem to be studied. It should have a simple title and a project number that can be referenced. It should also include the geometric scope of CFD modeling including any simplifications to be incorporated. If certain specific models need to be included in the study, they should be described as well. These could include simplifying a tube bundle by treating it as a porous resistance, the need for multi-phase modeling in oil fired burners, the need to include certain species in the combustion model, etc. If the project manager is not certain about it, then a request for this information from the CFD vendor must be included.
A list of key dates
Required proposal date
Expected start date
Required completion date
General arrangement drawings
Detailed drawings that include details and dimensions of the equipment in the scope such as burners, convection section, air ducts, air preheater, etc
Operating conditions to be modeled if they differ from the datasheets. Special attention should be paid to units and physical properties to be used.
The expected report format and the information to be included. This will encompass model description, inputs to the model, sectional views of velocity, temperature, pressure, species, isocontours to visualize flame shape and length, etc. Any specific data that needs to be validated by field measurements. Expectations for summary and recommendations to be detailed must also be included.
Terms and conditions. The project manager should also understand that the terms and conditions for a CFD vendor differ vastly from the equipment providers as CFD vendors are typically service providers. Enough lead time to negotiate contract terms should be included in the project the timeline estimate. Certain terms regarding intellectual property take longer to resolve and must be anticipated by all sides. It is a best practice to ask for CFD vendor’s terms and conditions with the proposal or request details of a master service agreement if one is in place already.
Vendor questionnaire about references, experience in CFD, specific examples of the project type, organization details, contact information, etc.
Standardizing this part of the solicitation will improve the quality of bids received, increase the probability of meeting the project expectations and reduce the lead time in going back and forth over the details. Moreover, the responses received through this standardized process will provide an apples-to-apples comparison of vendors, so you can impartially weigh the bids, reducing any favoritism in hiring a vendor and eliminating guesswork in the product that is delivered.
These savings in cost, time, and communication burden will enhance reliability of use of CFD in project cycles and reduce disruption and/or need for warranty work. This will be a win-win for companies that solicit CFD simulation work and for the CFD vendors.