In Brazil, approximately 20% of the industries use thermal systems with steam, that is, more than 70,000 thousand industries. Of these industries, most have more than one reducing valve in their process, aiming to adjust the pressure level of the boiler to the operating pressure of each of the equipment that operate with steam.
Most industries use saturated steam in their production process, presenting as one of the main characteristics the change of vapor / condensate phase (in heat exchangers) at constant temperature. This feature makes it possible, for example, to keep the industrial cooking temperature constant (depending on a certain steam pressure).
In these processes with saturated steam, after lowering the steam pressure in the valve, the outlet steam has the characteristic of superheated steam, considering the isentalpic thermodynamic modeling (Fundamentals of thermodynamics, Series Van Wylen 2018), which is not desired in the processes productive.
In most production processes, the temperature loss of superheated steam to the temperature of saturated steam occurs through the exchange of heat with the environment, that is, loss of energy.
A possible solution to avoid wasting energy in systems with reducing valves is through the use of desuperheater in the valve outlet piping, but even in this situation, according to the study “EXERGETIC ANALYSIS OF PRESSURE REDUCING VALVES FOR COGENERATION: CASE STUDY IN A CELLULOSE INDUSTRY (França and Soares, 2005), the best solution for this application is the use of steam turbines.
Discover the Pressure Reducing Turbine (TRP), PROSUMIR solution for energy use in systems with steam www.prosumir.com.br.
¹ Exergetic Analysis: balance of exergy in the analysis of thermal systems. This balance is similar to an energy balance, but it has the fundamental difference that, while the energy balance is based on the energy conservation law, the exergetic balance is based on the irreparable loss of exergy² due to all the real processes that are irreversible.
² Exergy: maximum work that can be obtained through the most appropriate process of a system that is in an initial state until it reaches the final state, characterized by the thermodynamic balance with the environment.