Process Engineering Division – Instrumentation and Automation Section – Daily Topics – Topic No. 2020-12-18
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Process Engineering Division – Instrumentation and Automation Section – Daily Topics – Topic No. 2020-12-18: Discussion topic: 330. For a set of throttling device steam flow meters, the originally designed steam pressure is 2.94 MPa and the temperature is 400°C. In actual use, the steam pressure at the measured point is 2.84 MPa (with constant temperature). When the flow meter indicates 102 t/h, what is the actual flow rate? (5 points are given only to those who provide the correct answer; additional points are awarded for a correct calculation process or detailed explanation.)
Actual M = Design M × SQRT(Actual ρ ÷ Design ρ) = 102 t/h × SQRT(9.5238 ÷ 9.8668) = 102 t/h × 0.9825 = 100.2 t/h. Therefore, the actual flow rate is 100.2 t/h
Actual M = Design M × SQRT(Actual ρ ÷ Design ρ) = 102 t/h × SQRT(9.5238 ÷ 9.8668) = 102 t/h × 0.9825 = 100.2 t/h. Therefore, the actual flow rate is 100.2 t/h
For a set of throttling device steam flow meters, the originally designed steam pressure was 2.94 MPa and the temperature was 400°C. In actual use, the steam pressure at the measured point is 2.84 MPa (with constant temperature). When the flow meter indicates 102 t/h, what is the actual flow rate? Solution: According to the table, for water vapor density at 2.94 MPa and 400°C, ρ = 9.8668 kg/m3 ； At 2.84 MPa and 400°C, ρ = 9.5238 kg/m3 ； Actual flow rate = Design flow rate * sqrt(ρ_actual/ρ_design). Actual flow rate = 102 * sqrt(9.5238/9.8668) = 102 * 0.9825 = 100.2 (t/h). Answer: The actual flow rate is 100.2 t/h.
According to the table: for water vapor density, at 2.94 MPa and 400°C, ρ = 9.8668 kg/m3； At 2.84 MPa and 400°C, ρ = 9.5238 kg/m3 ； Actual flow rate = Design flow rate * sqrt(ρ_actual/ρ_design). Actual flow rate = 102 * sqrt(9.5238/9.8668) = 102 * 0.9825 = 100.2 (t/h).
Refer to the water vapor density table: at 2.94 MPa and 400°C, ρ = 9.8668 kg/m3； At 2.84 MPa and 400°C, ρ = 9.5238 kg/m3. The actual M value = design M value × √(actual ρ / design ρ) = 102 × √(9.5238 / 9.8668) = 100.2 t/h.
Refer to the water vapor density table: at 2.94 MPa and 400°C, ρ = 9.8668 kg/m3； At 2.84 MPa and 400°C, ρ = 9.5238 kg/m3. The actual M value = design M value × √(actual ρ / design ρ) = 102 × √(9.5238 / 9.8668) = 100.2 t/h.