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GearPump1_CL

This procedure provides a simple model of a gear pump.  The volumetric flow rate is determined from displacement rate less leakage flow.  Power is determined from overall efficiency applied to displacement flow rate.  The parameters V_disp, K_leak, and eta_o can be obtained from manufacturer's performance data.

Inputs:

F\$:  fluid string identifier

C:  concentration (%) {applicable when F\$ is a brine.  Otherwise set C=0.}

T_in:  inlet temperature (K, C, F, or R)

P_in:  inlet pressure (bar, atm, Pa, kPa, MPa)

P_out:  outlet pressure (bar, atm, Pa, kPa, MPa)

N:  rotational speed (1/s)

V_disp: displacement of pump per cycle (in^3 or m^3)

K_leak:  leakage constant (in^2 or m^2);  if K_leak<0, then a typical value will be used

eta_o:  overall efficiency of pump (-)

Outputs:

m_dot:  mass flow rate (kg/s or lb_m/hr)

T_out:  outlet temperature (K, C, F, or R)

W_dot:  power (W, kW or Btu/hr)

eta_p:  actual efficiency relative to power

eta_v:  volumetric efficiency

Example 1:

\$UnitSystem SI Mass kJ C kPa

\$VarInfo m_dot units=kg/s

\$VarInfo T_out units=C

\$VarInfo W_dot units=kW

T_in=25 [C]

P_in=100 [kPa]

P_out=500 [kPa]

F\$='Water'

C=0 [%]

N=1700 [1/min]*convert(1/min,1/s)

V_disp=0.06 [liter]*convert(liter,m^3)

K_leak=3 [mm^2]*convert(mm^2,m^2)

eta_o=0.6 [-]

Call gearpump1_cl( F\$, C, T_in, P_in, P_out, N, V_disp, K_leak, eta_o: m_dot, T_out, W_dot, eta_p, eta_v)

{Solution:

eta_p=0.5787

eta_v=0.9647

m_dot=1.635 [kg/s]

T_out=25.08 [C]

W_dot=1.133 [kW]

}

Example 2:

\$UnitSystem SI Mass kJ C kPa

\$VarInfo m_dot units=kg/s

\$VarInfo T_out units=C

\$VarInfo W_dot units=kW

T_in=25 [C]

P_in=100 [kPa]

P_out=500 [kPa]

F\$='EG'  {ethylene glycol - water solution}

C=20 [%]

N=1700 [1/min]*convert(1/min,1/s)

V_disp=0.06 [liter]*convert(liter,m^3)

K_leak=3 [mm^2]*convert(mm^2,m^2)

eta_o=0.6 [-]

Call gearpump1_cl( F\$, C, T_in, P_in, P_out, N, V_disp, K_leak, eta_o: m_dot, T_out, W_dot, eta_p, eta_v)

{Solution:

eta_p=0.5791

eta_v=0.9651

m_dot=1.677 [kg/s]

T_out=25.17 [C]

W_dot=1.133 [kW]}