Summary:

In the contribution is submitted proposal of the vessel construction for water for industrial use. For heating is being used the secondary heat from the cooling system. More frequent utilization of this energy is limited of present by two facts: 1. The cooling devices contain toxic charge and therefore the pipeline for cooling medium passing through must not be in direct contact with the heated water for hygiene and safety reasons. 2. Sufficient thermal difference for effective heat sharing is possible only when the cool water is supplied to the place of heating.
The suggested construction solves both these problems. The primary pipeline with ammonia is located on the container outer side into other heat-carrying protective medium. The inner arrangement provides the isothermal water stratification in container. In to the container is located the insert from non-conductive material with outer dimension smaller than the inner diameter of container. This enables formation of the slot filled by the heated water. Between the hot water in the slot and cold water inside the vessel creates the pressure difference, heated water rises into the upper part of the container and cold water is sucked into the slot from the bottom. Within the heating almost whole container volume is therefore reached steady thermal gradient between the heating and heated medium and maximum effectiveness of the heat sharing.
After verification of the suggested construction the device prototype is manufactured enabling monitoring of the temperature course in various parts of the device in dependence on time. The temperature layout inside the container was monitored by five thermal sensors located in the vessel centre line in distance of 150 mm (Fig. 3). From the measuring results is evident the heated water stratification inside the vessel. To the heating point is continuously supplied water of initial temperature (Fig. 4) for 15 minutes. Nevertheless, from the measured temperature resulted that the cooling medium secondary heat is not utilized sufficiently. The maximum output of the device at the heating beginning is almost 5 kW. This it will be necessary to extend the heat-exchanging surface of the exchanger or to adapt the slot shape along the vessel periphery to reach lower flow rate of the heated water.
The described device will enable after the suggested adaptation the effective utilization of the secondary heat of the cooling medium without risk of its penetration into the heated water.