A Novel Temperature vs Pessure drop Grid Diagram for Energy Saving in Heat Exchanger Network Retrofit

Резюме

Pressure drop in the heat exchanger is a key issue that should be considered in the HEN retrofit, as increasing the pressure of fluid can cost a substantial amount of energy. To accurately estimate the cost-related trade-off factors, the relative cost of pressure drop and heat transfer performance should be determined for each heat exchanger and generally for the whole heat exchanger network. However, there is still lacking a graphical method that can visualise the pressure drop together with a heat exchanger network retrofit. This paper proposes a new Temperature vs Pressure drop (TVPD) Grid Diagram to consider the pressure drops in heat exchangers when retrofitting a heat exchanger network. The method includes the proper design of heat exchangers based on the full utilisation of allowable pressure drop, where several commonly used types of heat exchangers are considered, including shell-and-tube heat exchangers and plate heat exchangers of plate-and-frame and brazed construction commonly used in industry. The new Grid Diagram can be used for energy targeting, visualising the temperature range of different heat exchanger types, and pressure drop. The method provides guidance for engineers to design a heat exchanger network with both considerations on pressure drop and heat recovery.