When purchasing a plate-and-shell heat exchanger, the first things to confirm are the heat load under design conditions, the inlet and outlet temperatures of the media, the allowable pressure drop, and the installation space dimensions. These parameters directly determine the selection of heat transfer area and the number of plates. For example, in district heating projects, the temperature difference and flow rate between the primary and secondary sides determine the required heat transfer area; if installation space is limited, a compact structure should be given priority. In addition, the shell-side design pressure, design temperature, and the cleanliness of the plate-side medium should also be provided so that the supplier can reasonably determine the plate spacing and flow channel configuration.
The choice of plate material is mainly based on the corrosiveness of the medium. For HVAC circulating water or district heating hot water, 304 or 316L stainless steel is usually sufficient; if the medium contains chloride ions or is acidic, it is necessary to evaluate whether titanium plates or higher-grade alloys should be used. The temperature and pressure resistance of the gaskets is equally critical. Common EPDM rubber is suitable for hot water conditions, while NBR is used for oil-based or low-temperature media. Purchasing personnel should require the supplier to provide a compatibility statement between materials and media, and verify whether the sealing form (such as clip-on or adhesive-bonded) facilitates later maintenance and replacement.
The plate-and-shell heat exchanger combines the high heat transfer efficiency of a plate heat exchanger with the relatively good pressure resistance of a shell-and-tube heat exchanger. When the shell-side pressure is relatively high and the plate-side medium is relatively clean, this structural form is more suitable. The BRQ-300 design strengthens the connection strength between the shell and the plate pack, allowing the shell side to withstand higher working pressure while the plate-side flow channels maintain a smaller equivalent diameter, which helps maintain turbulent flow and heat transfer efficiency. During procurement, it is necessary to confirm with the supplier the specific values of the shell-side design pressure and the plate-side design pressure, and to verify whether they meet the relevant pressure piping code requirements of the project.
In addition to the conventional material certificates and pressure test reports, it is recommended to explicitly require in the procurement contract that the supplier provide the selection calculation sheet, plate assembly drawing, and gasket specification list. The selection calculation sheet should include the calculation process for heat transfer area, heat transfer coefficient, and pressure drop, so that it can be compared during later operation. As gaskets are wearing parts, their specifications and supply channels should be stated in the contract to ensure maintenance convenience. For continuous operation scenarios such as chemical process cooling, the supplier may also be required to provide a recommended spare parts list.
