Division 2.2.4.3: SSV-CVS system - Commission Delegated Regulation (EU) 2017/654 of 19 December 2016 supplementing Regulation (EU) 2016/1628 of the European Parliament and of the Council with regard to technical and general requirements relating to emission limits and type-approval for internal combustion engines for non-road mobile machinery

The diluted exhaust gas mass over the cycle m _ed [kg/test] shall be calculated by means of equation (7-39), if the temperature of the diluted exhaust gas is kept within ± 11 K over the cycle by using a heat exchanger:

m _ed = 1,293 · q_V _SSV · Δt

(7-39)

Where:

1,293 kg/m³

air density at 273,15 K and 101,325 kPa

Δt

cycle time [s]

q_V _SSV

air flow rate at standard conditions (101,325 kPa, 273,15 K) [m³/s]

with

q_{V SSV} = \frac{A_{0}}{60} d_{2}^{v} C_{d} P_{p} \sqrt{[\frac{1}{T} (r_{1,4286}^{p} - r_{1,7143}^{p}) \times (\frac{1}{1 - r_{4}^{D} r_{1,4286}^{p}})]}

(7-40)

Where:

A ₀

collection of constants and units conversions = 0,0056940 $[\frac{m^{3}}{\min} \times \frac{K^{\frac{1}{2}}}{kPa} \times \frac{1}{{mm}^{2}}]$

d _V

diameter of the SSV throat [mm]

C _d

discharge coefficient of the SSV [-]

p _p

absolute pressure at venturi inlet [kPa]

T _in

temperature at the venturi inlet [K]

r _p

ratio of the SSV throat to inlet absolute static pressure, $(1 - \frac{Δ P}{P_{a}})$ [-]

r _D

ratio of the SSV throat diameter to the inlet pipe inner diameter $\frac{d}{D}$ [-]

If a system with flow compensation is used (i.e. without heat exchanger), the mass of the diluted exhaust gas m _ed, _i [kg] during the time interval shall be calculated by means of equation (7-41):

m _ed, _i = 1,293 · q_V _SSV · Δt _i

(7-41)

Where:

1,293 kg/m³

air density at 273,15 K and 101,325 kPa

Δt_i

time interval [s]

q_V _SSV

volumetric flow rate of the SSV [m³/s]

Division 2.2.4.3 SSV-CVS system