기계

밀폐탱크의 DPT Range 계산식

Closed Tank Liquid Level(with wet leg)

DPT의 High Pressure Connection이 압력용기의 하부에 접속시 다음과 같다.

P1 :Drum Pressure (               )kg/cm2G. rw :Density of saturated water (               )g/cm3AT P rs :Density of saturated steam (               )g/cm3AT P ro :Density of reference LEG (               )g/cm3AT 20 C H :Length of reference LEG (               ) mm h :Measuring range (               ) mm h1 :Length between lower tap and 0% level (               ) mm h2 :Length between uper tap and 100% level (               ) mm Ph :High pressure of D/P cell PL :Low pressure of D/P cell

The following equation will be consisted from the above conditions.

PL = P1 + ( H x ro ) = P1 + ( h1 + h + h2 ) x ro

Phmin = P1 + ( h1 x rw ) + ( h + h2 ) x rs

Phmax = P1 + ( h1 + h ) x rw + ( h2 x rs )

Therefore

DP o  = Phmin      -       PL

        = h x ( rs - ro ) + h1 x ( rw - ro ) + h2 x ( rs - ro )

        = (           0) x (          0) - (           0)

        =              0  mmH2O

DP100  = Phmax      -      PL

           = h x ( rw - ro ) + h1 x ( rw - ro ) + h2 x ( rs - ro )

           = (         0) x (          0) - (           0)

           =           0  mmH2O

Then, the calibration of D/P cell shall be done as following.

            DP = DP o ~ DP100 mmH2O

            =                 ~             mmH2O

밀폐탱크의_DPT_Range_계산.pdf