Heat Recovery Steam Generator is a part of a power plant, which generates steam. The heat recovery steam generator used a gas turbine to operate, by using the flue (gas) from the exhaust of the gas turbine Figure 1. The heat exchanges process occurs between the boiler and exhaust gas, which is used to heat water in a boiler to raise the pressure of the steam. [1] In addition, the gas turbine is used for power source due to it has some advantages such as can be started quickly, can be easily assembled and erected and the main advantage is it has a high efficiency of 25% to 25% with required little cooling water as mentioned by V.Ganapathy (1996).
Figure 1: Schematic diagram of a Gas Turbine The boiler consists of three major components, …show more content…
Besides, a bypass damper system, also called as an isolating damper system with seal air fans is necessary to ensure the hot gases do not leak to fan when the gas turbine is running. [2]. The formula below is used to express the leakage of gas across a damper by stating the assumptions, which most of dampers used for isolation of gas or air in ducts are nor 100% leak proof. They have a certain percentage of leakage which cause a flow of gas across the area. Considering the conditions to be similar to those of flow across an orifice,
V_g= C_d √(2gH_w ρ_w/〖2ρ〗_g ) ………………………………..Equation 1
where; V_g is gas velocity through the leakage area in fps unit H_wis differential pressure across the damper in WC unit ρ_w and ρ_g is density of gas and water in lb/cu ft, g is acceleration due to gravity in ft/s2unit Cd coefficient of discharge which is 0.61
The gas flow W in lb/h can be obtained from W = 3600 ρ_g A (100 - E) (V_g/100)…………………………….. Equation 2
Where E is the sealing efficiency on an area basis (%). Most dampers have an E value of 95 - 99 %. A is the duct cross section, ft2. Based on equation (1) and (2), simplifying will have
W=2484A (100-E) √(H_w/(460+t))
Where t is the gas air temperature in oF
Figure 1: Schematic diagram of a Gas Turbine The boiler consists of three major components, …show more content…
Besides, a bypass damper system, also called as an isolating damper system with seal air fans is necessary to ensure the hot gases do not leak to fan when the gas turbine is running. [2]. The formula below is used to express the leakage of gas across a damper by stating the assumptions, which most of dampers used for isolation of gas or air in ducts are nor 100% leak proof. They have a certain percentage of leakage which cause a flow of gas across the area. Considering the conditions to be similar to those of flow across an orifice,
V_g= C_d √(2gH_w ρ_w/〖2ρ〗_g ) ………………………………..Equation 1
where; V_g is gas velocity through the leakage area in fps unit H_wis differential pressure across the damper in WC unit ρ_w and ρ_g is density of gas and water in lb/cu ft, g is acceleration due to gravity in ft/s2unit Cd coefficient of discharge which is 0.61
The gas flow W in lb/h can be obtained from W = 3600 ρ_g A (100 - E) (V_g/100)…………………………….. Equation 2
Where E is the sealing efficiency on an area basis (%). Most dampers have an E value of 95 - 99 %. A is the duct cross section, ft2. Based on equation (1) and (2), simplifying will have
W=2484A (100-E) √(H_w/(460+t))
Where t is the gas air temperature in oF