Утилізація теплоти димових газів котельні шляхом використання органічного циклу Ренкіна

Abstract

Визначається доцільність впровадження на водогрійній котельні з котлами ПТВМ-100, що спалюють природний газ, утилізаційної електрогенеруючої установки. Остання побудована на базі органічного циклу Ренкіна та обігрівається димовими газами котлів. Показано, що ефективним робочим тілом для такої установки є фреон R600a. Виконано розрахунки теплової схеми установки на трьох режимах функціонування на протязі року; визначені терміни її окупності при електричній потужності 100, 200 та 300 кВт.

A feasibility of the installation of energy saving cogeneration plant in the high-power water heating boiler room has been studied. The boilerroom is equipped with the four PTVM-100 boilers with the heat capacity of 100 GCal/year that fire natural gas. The two boilers are used to cover the heat loading of it. The energy-saving power generating plant was built on the basis of organic Renkine cycle (ORC) and it is heated by boiler flue gases of 90 to 117 °С.Technical characteristics of PTVM-100 boilers were analyzed using the process flow diagrams and their average thermal loading in summer, in winter and for transient seasons was calculated. Many energy-saving schemes were proposed for the ORC to utilize the heat of flue gases of boilers. Consideration was given to the freon characteristics that are used for the operation with lowtemperature energy carriers. The freons R600a and R142b were chosen as promising low-boiling actuating media for the ORC. Based on a minimum of required investments we selected a simple heat balance circuit with the ORC loop. A comparison of computation characteristics of heat balance circuit in summer, in winter and during transient periods showed that freon R600a is an efficient actuating medium for it. It has been shown that the payback period for suggested cogeneration plants of 100, 200 and 300 KW is equal to 11, 13 and 16 months, accordingly (the project realization time was not taken into consideration) for the investments of 200, 400 and 600 thousand USD.