Boiler steam flow compensation (differential pressure transmitter)
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1: press_act – The actual pressure value inside the steam drum. 2: temp_act – The actual temperature of the steam drum. Using these two values, along with the international industrial standard IAPWS algorithm, the density of the steam at the current pressure and temperature is calculated, denoted as RHO_ACT. 3: press_cal – This refers to the pressure calculation based on the orifice plate; the value is 29.063 bar. 4: temp_cal – This refers to the temperature calculation based on the orifice plate; the value is 234 degrees. Using these two values, again with the IAPWS algorithm, the density of the steam at the current pressure and temperature corresponding to the orifice plate is calculated, denoted as RHO_CAL. FLOW_TRANS: The flow rate of steam exiting the steam drum, in t/h. Therefore, the steam drum flow compensation is calculated as (RHO_ACT/RHO_CAL)^1/2*FLOW_TRANS. I’m not sure what this compensation formula means
1 and 2 are used to determine the actual steam density； 3 and 4 are used to determine the steam density during design ； Actual steam density at the orifice plate / Steam density at design time, to obtain the correction factor for the orifice plate output (which is actually also the correction factor for the differential pressure transmitter output) ； Taking the square root of the correction value for the orifice plate output yields the correction value for the flow rate. For example: at 0.6 MPa and 165°C, the density of saturated steam is approximately 3.67; at 0.5 MPa and 159°C, the density of saturated steam is also approximately 3.67. If the former is the design value and the latter is the measured value. Therefore, the differential pressure output should be multiplied by the correction factor of 0.866. If the traffic value after opening is adjusted, multiply it by the square root of 0.866, which is 0.930.