Integrated Heat Recovery of Waste Gases and Ventilation Emissions in a Multilayer Plate Heat Exchanger

One of the main problems in the operation of ventilation and air conditioning systems is the low efficiency of using low-potential heat emitted together with the fluxes of exhaust gases and ventilation emissions from the premises of industrial enterprises, public, administrative, residential buildings and structures. To solve the above problem in modern ventilation and air conditioning systems, heat recuperators and heat exchangers of various designs are used, while plate recuperators are the most effective and widespread. The main characteristic of a plate heat exchanger is the amount of heat transferred through a unit of heat exchange surface area at a temperature difference—the heat transfer coefficient. In order to increase the efficiency of heat exchange of plate heat exchangers, various methods of intensifying the heat transfer process are used, one of which is the installation of turbulators of various shapes and types of their location. This article presents the results of experiments conducted on a complex multilayer plate heat exchanger with integrated Peltier elements and cylindrical turbulators installed in a staggered and corridor arrangement, which allows to utilize low-potential heat while simultaneously obtaining thermoelectricity. The aim of the work is an experimental study of the temperature regime in the intersectional space of a complex multilayer plate heat exchanger during the utilization of waste gas heat and ventilation emissions for heating supply air and associated production of thermoelectricity. An original design of a complex multilayer plate heat exchanger is proposed. Experimental studies have been carried out at a fixed coolant velocity and air flow temperature, graphs of the dependences of thermoelectricity generation on the operating time of the experimental installation have been constructed. Due to the use of cylindrical turbulators, turbulence of flows increases, as a result of this, the heat transfer process is intensified with the associated production of thermoelectricity. The high efficiency of using a complex multilayer plate heat exchanger, turbulators with a staggered arrangement in comparison with a corridor and without their installation in the design of the cooling system has been established. The resulting electricity can be used for additional heating of the supply air or to ensure the autonomous operation of the automation and control system of the ventilation unit.