A plate heat exchanger (PHE) is a modern, effective type of heat transfer equipment capable of increasing heat recuperation and energy efficiency. For PHEs, enhanced methods of heat transfer intensification can be further applied using the analysis and knowledge already available in the literature. A review of the main developments in the construction and exploration of PHEs and in the methods of heat transfer intensification is presented in this paper with an analysis of the main construction modifications, such as plate-and-frame, brazed and welded PHEs. The differences between these construction modifications and their influences on the thermal and hydraulic performance of PHEs are discussed. Most modern PHEs have plates with inclined corrugations on their surface that create a strong, rigid construction with multiple contact points between the plates. The methods of PHE exploration are mostly experimental studies and/or CFD modelling. The main corrugation parameters influencing PHE performance are the corrugation inclination angle in relation to the main flow direction and the corrugation aspect ratio. Optimisation of these parameters is one way to enhance PHE performance. Other methods of heat transfer enhancement, including improving the form of the plate corrugations, use of nanofluids and active methods, are considered. Future research directions are proposed, such as improving fundamental understanding, developing new corrugation shapes and optimisation methods and area and cost estimations.

Highlights ► The developments in design theory of PHE purposing to increase heat recovery and efficiency of energy usage have been analysed. ► The developed mathematical model of PHE estimates the optimal multi-pass plate-and-frame heat exchanger with mixed grouping of plates. ► The parameters to calculate heat transfer coefficients and friction factors for PHEs with some commercial plates are determined. ► The described approach is implemented in software for plate heat exchangers calculation. ► Two case studies, which illustrate PHEs applications in process industries performed.

Of the many different approaches available to mitigate fouling, the use of enhanced heat transfer surfaces is a principal method. The flow in channels of plate heat exchangers (PHEs) has high levels of turbulence due to the channels intricate geometry. In principle therefore, this type of heat transfer augmentation should lead to fouling mitigation. The effects of process parameters on fouling in PHE channels are studied in this article. The asymptotic behaviour of water fouling is examined specifically and the net rate of fouling accumulation is described as the difference between the fouling deposition rate and the fouling removal rate. An equation is proposed to account for how the fouling resistance varies with time. The conclusion is that for scaling there exist threshold conditions on wall shear stress, wall temperature and salt content, beyond which fouling deposition starts. The fouling deposition rate expression proposed for tubes incorporating heat transfer enhancement as used by Yang and Crittenden is adapted to be used in a new model for PHEs. Comparison with experimental data published in the literature reveals good agreement with the proposed model. The model can then be used to predict cooling water fouling development over time for all the heat exchangers in a chosen industrial circuit