Restrictor2

Restrictor2_CL

Restrictor2_CL provides an estimate of the mass flow rate through a short-tube restrictor with L/D ratios between 4 and 30 and a chamfered inlet for use in refrigeration cycles. The mass flow rate is estimated from an empirical relation that has been derived based on data and other information in papers listed below. The effect of the chamfer is taken from Aaron and Domanski, which was tested for R22. It is assumed that the correlation that provide can for the chamfer effect can be applied to other refrigerants.

Aaron, D.A., and P.A. Domanski. 1990. Experimentation, analysis, and correlation of Refrigerant-22 flow through short tube restrictors. ASHRAE Transactions 96(1):729-742.
Krakow, K. I., and Lin, S, 1988, Refrigerant flow through orifices, ASHRAE Transactions, Vol. 94, Part 1: 484-506.
Payne, W.V., and D.L. O'Neal. 1998. Mass flow characteristics of R-407 through short tube orifices. ASHRAE Transactions 104(1).
Payne, W.V., and D.L. O'Neal. 1999. Multiphase flow of refrigerant 410A through short tube orifices. ASHRAE Transactions 105(2).
Kim. Y. and O'Neal, D.L, 1994, Two-phase flow of R22 through short-tube orifices, ASHRAE Transactions 100(1)
Payne, W.V., and D.L. O'Neal. 1999. Multiphase flow of refrigerant 410A through short tube orifices. ASHRAE Transactions 105(2).

Inputs:
R$: name of the refrigerant
d: inner diameter of the capillary tube (m, ft)
L: length of the capillary tube (m, ft)
DEPTH depth of chamfer (m, ft)
P_in: pressure at the capillary tube inlet (Pa, kPa, MPa, bar, psia, atm)
h_in: specific enthalpy at the restrictor inlet (J/kg, kJ/kg, Btu/lbm)

Output:
m_dot: mass flow rate (kg/s, lbm/hr)

Example:

$UnitSystem SI C kPa kJ mass
R$='R22'
P_in=1.355 [MPa]*convert(MPa,kPa)
T_sat=temperature(R$,P=P_in,x=0)
DELTAT_sc=5.6 [DELTAK]
h_in=enthalpy(R$,T=T_sat-DELTAT_sc,P=P_in)
d=1.34 [mm]*convert(mm,m)
L=12.7 [mm]*convert(mm,m)
DEPTH=0.25 [mm]*convert(mm,m)
Call Restrictor2_CL(R$, d, L, DEPTH, P_in, h_in : m_dot)
m_dot_hr=m_dot*convert(kg/s,kg/hr)

{Solution:
m_dot=0.03257 [kg/s]
m_dot_hr=117.2 [kg/hr]
}

Index