3 Analysis of diverse heat recovery steam cycles Report

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Politecnico di Milano MSc. Energy Engineering – Power Production Energy Conversion A Prof. Gianluca Valenti PROJECT 3 COMPARISON OF HEAT RECOVERY STEAM CYCLES a.y. 2015/16 Giulia Boschi Omar Brembilla Alessandro Mosca 2 LOOKING FOR THE PARAMETERS OF THE GAS TURBINE We are considering the same simple cycle gas turbine as project 2. First of all, we need to know if we are dealing with a heavy duty gas turbine or with an aeroderivative one, so we have to analyze the characteristic quantities of the given turbogas. 𝑚̇ 𝑓𝑢𝑒𝑙 = 𝑃𝐺𝑇,𝑆𝐶 𝜂𝐻𝐻𝑉,𝐶𝑆 ∗ 𝐻𝐻𝑉 = 12.55𝑘𝑔 𝑠 𝑃𝐺𝑇,𝐶𝐶 = 𝑃𝐺𝑇,𝑆𝐶 − 𝑚̇ 𝑒𝑔(ℎ𝐶𝐶 − ℎ5) = 231.38 𝑀𝑊 𝜂𝐻𝐻𝑉,𝐶𝐶 = 𝑃𝐺𝑇;𝐶𝐶 𝑚̇ 𝑓𝑢𝑒𝑙 ∗ 𝐻𝐻𝑉 = 0.332085 The reference ranges for heavy duty and aeroderivative gas turbines are the following: HEAVY DUTY AERODERIVATIVE P net [MW] 200 ÷ 400 < 50 𝛽 15 ÷ 20 30 ÷ 40 𝜂𝑛𝑒𝑡 25% ÷ 35% 37% ÷ 43% Looking at our turbine data, we are definitely dealing with a heavy duty one, since the power output is really high. We use now the software Turbogas to perform our plant analysis. Turbogas identifies any plant with TIT (Turbine Inlet Temperature), pressure ratio and air mass flow rate at the compressor intake, data that are not given in our problem. We need then to assume these data, according to the heavy duty turbine ranges, so that the working conditions result similar to the ones of our own turbine. Assuming the following working parameters: 𝛽 = 18 𝑇𝐼𝑇 = 1270 °𝐶 𝑚̇ 𝑎𝑖𝑟 = 650𝑘𝑔 𝑠 The turbogas performance parameters that we wanted to keep under control are the following: 𝑃𝐺𝑇,𝐶𝐶 = 238.79 𝑀𝑊 𝜂𝐻𝐻𝑉,𝐶𝐶 = 0.3524 With the data that we have just obtained from the software, we investigate in depth the three combined cycle configurations that we are given. 3 a) One Evaporation Level We set as evaporation pressure the optimized value of the previous project.…