Article by Daniel Sweet
“For this project, we started with all new equipment. Everything was custom-designed to suit the needs of the network, so there were a lot of decisions to make about suppliers and material. At the end of the planning phase, we ended up with two types of heat exchangers, each made from steel alloys. Specifically, we have three carbon steel shell and tube heat exchangers that exchange heat from liquid streams to the closed water loop in Pernis.”
“On the stainless end, we have one stainless steel 316 plate and frame heat exchanger that transfers steam condensate to the refinery’s closed water loop. Finally, we have one stainless steel 316 plate and frame heat exchanger that transfers the heat from the internal water loop to the distributor’s system. This is the contact point between the residual heat network and the end users, or the residents of Rotterdam.
In regard to the use of stainless steel, Willert said the material was a natural choice for this kind of network. “The two stainless steel plate and frame heat exchangers were selected for their high efficiency, which helps end users get the most out of the energy we can supply. And though stainless steel would of course be the right material for corrosive streams, corrosion does not happen to be a factor in this project, as both water streams are non-corrosive.”
”I keep the company’s heat exchangers running while at the same time I work to keep the company competitive.”
After the heat is fed via Shell’s pipeline into the existing Warmtebedrijf Rotterdam network, it moves to local heat distributors and, finally, to local consumers. Warmtebedrijf Rotterdam is responsible for the management, operation, and maintenance of this process, but Shell remains in constant communication with the company to ensure the success of the project. As Willert explained, “with a project like this, you have to make sure that both parties are adequately supplied. On one end, Shell will always have heat available as a byproduct of our refinery processes. So if the domestic users do not need the heat—in the summer, for example—we use our existing air coolers to dispose of the residual energy. And at the same time, the distributors and users must have their own backup, in case they cannot take the heat energy from our network. In that way, everybody has a reserve plan. We can cool the heat down on our own, and the circulating company can provide heat from other sources.”
In addition to his engineering duties for the Pernis Residual Heat Initiative, Willert is active in several other roles within Shell. His duties range from heat exchange maintenance to product development, which as Willert puts it, “keeps things interesting. I have a varied job—sometimes I am needed to troubleshoot existing heat exchangers when problems occur. I also work on new building projects by creating site-specific specifications and designing heat exchangers for installation. On the more theoretical side, I work in research and development to create new prototypes, and then I test them to see how they might fit into the current business. In this way, I keep the company’s heat exchangers running while at the same time I work to keep the company competitive.”