THE ECONOMIC EFFICIENCY EVALUATION OF THE CONDENSING HEAT EXCHANGER OPERATION
THE PURPOSE. The article discusses the scheme of the flue gases heat deep utilization. It has been established that in boiler units operating on natural gas, the only way to significantly improve the use of fuel is to deeply cool the combustion products to a temperature at which it is possible to condense the maximum possible portion of the fumes contained in the gases. It is shown that for a typical scheme, a sufficiently high efficiency of the installation will be achieved if the temperature of the return network water does not exceed 45 °C. At a higher temperature, the proportion of water vapor that will condense is significantly reduced, which, in turn, reduces the heat recovery efficiency. METHODS. The most common case with an open urban heat supply system, where the recharge amount of the heating network is significant, is considered as a basic option. As the calculations show, the energy effect share from using the load of hot water supply (HWS) in this scheme, depending on the boiler load, is from 50 to 60% of the total technically achievable result. It is an essential factor in deciding to implement this technology. RESULTS. According to the calculation for the PTVM-100 boiler, it can be seen that in the maximum mode the effect of cooling flue gases is comparable with the condensation effect. CONCLUSION. The economic efficiency assessment is carried out, which is defined as the cost of saved fuel - natural gas obtained during the introduction of a condensing unit.