Leak detection of heat transfer element for steam type gas heater

TLDR: In this paper, the authors proposed a method to check existence of leak of a heat transfer element due to corrosion or the like without stopping an equipment by a method wherein the inside of the heat transfer elements is made negative pressure and the existing concentration of harmful constituents of gas in condensed water is measured.

Abstract: PURPOSE:To check existence of leak of the heat transfer element due to corrosion or the like without stopping an equipment by a method wherein the inside of the heat transfer element is made negative pressure and the existing concentration of harmful constituents of gas in condensed water is measured. CONSTITUTION:A regulating valve 2, for regulating the amount of steam or condensed water, is provided at the inlet and outlet port of the heat transfer element to make the pressure inside of the heat transfer element negative by regulating the regulating valve 2 in accordance with necessity in order to induce gas containing the harmful constituents through openings in case the openings are generated in the heat transfer element by corrosion or the like. In this case, the pressure inside of the tube panel 1 of the steam type gas heater is made negative one by one by choking the steam amount regulating valve 2 for a given period of time in a constant interval and fully closing a condensed water intercepting valve 3 by the signal of a control box 6 so that no trouble is caused in the temperature rise of exhaust gas. Then, the existing concentration of the harmful constituents in the condensed water is measured in a detector 5 by a signal from a detecting terminal 4, the amount of the harmful constituents resolved in the condensed water is evaluated based on the measured value and, thus, the leak is detected. This kind of check is repeated sequentially with respect to respective panels.