Design of a water heating tank based on utilization of the waste heat energy of refrigerants

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 ...

Analysis of leakage influence within capillary heat pipe recuperative heat exchanger

The paper analyses the leakage of air-to-air recovery heat exchanger consisting of 100 capillary thermal tubes 1.5 m long and aligned in ten rows. The operation of the recovery exchanger prototype was tested in a pigsty. The analysis focuses on how the exchanger leakage affects the heat utilisation efficiency of the air ducted from the pigsty, changes in supply/exhaust air flow rate ratio, supply air temperature, thermal output obtained, and exchanger’s total thermal and mass balances. The results obtained in in-process measurements and the mass and thermal balances show that the exchange leakage causes the outside supply air to contain 12.1–37.3% of the pigsty exhaust air. The percentage of the pigsty air increases with the increase of mass flow rates of supply and exhaust air. This leakage resulted particularly in a major change in supply and exhaust air mass flow rates, higher moisture content, temperature and thermal flow of the air conducted in the pigsty. The change in air flow rates resulted in ventilation change so that the overpressure ventilation took place instead of balanced ventilation. This change led to increased thermal losses by air penetrating through leaks in the peripheral building structures. Increased supply air moisture content made it ...