Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:99:p19
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 99 (pt 19/39)
Character Range: 1205394–1208399

cycle.

               Calculate a corresponding THCGER in mg/kWh using the following formula:

              THCGER = NMHCPI + (CH4PI * GERWHTC)

               Determine the applicable THC limit in mg/kWh using the following method:

               If  THCGER  ≤ CH4PI, then

              (a) THC limit value = THCGER; and

              (b) No applicable CH4 and NMHC limit value

               If THCGER  > CH4PI, then

              (a) No applicable THC limit value; and

              (b) Both the NMHCPI and CH4PI limit values are applicable.

              In this procedure:

              NMHCPI is the NMHC emission limit over the WHTC test-cycle and made applicable to PI engine by paragraph 5.3. of this Regulation;

              CH4PI is the CH4 emission limit over the WHTC test-cycle and applicable to PI engine by paragraph 5.3. of this Regulation.

Figure 1
Illustration of the HC limits in the case of a HDDF Type2 engine operating in dual-fuel mode during the WHTC cycle (natural gas dual-fuel engines)

              5.2.4. PM number limit (in #/kWh) applicable to HDDF Type 2A engines and to HDDF Type 2B engines operating in dual-fuel mode during the WHTC test cycle.

              In the case a PM number limit applicable to PI engines over the WHTC test-cycle would be defined in paragraph 5.3. of this Regulation, the following calculation procedure shall apply to HDDF Type 1A engines, to HDDF Type 1B engines, to HDDF Type 2A engines, to HDDF Type 2A and to HDDF Type 2B engines tested in the WHTC cycle while operating in dual-fuel mode:

               Calculate the average gas ratio GERWHTC over the hot part of the WHTC test cycle, then

              Calculate the PM number limit values PN limitWHTC in #/kWh applicable over the WHTC test-cycle using the following formula (linear interpolation between the CI and PI PM number limit values):

              PN limitWHTC = PN limitCI/WHTC + (PN limitPI/WHTC – PN limitCI/WHTC)* * GERWHTC

              where:

              PN limitPI/WHTC is the PM number limit applicable to PI engines over the WHTC test cycle;

              PN limitCI/WHTC is the PM number limit applicable to CI engines over the WHTC test cycle.

Figure 2
Illustration of the PN limits in the case of a HDDF Type 2 engine operating in dual-fuel mode during the WHTC cycle
5.3. Emission limits applicable to HDDF Type 3B engines operating in dual-fuel mode
              The emissions limits applicable to HDDF Type 3B engines whether operating in dual-fuel mode or in diesel mode are the exhaust emission limits applicable to CI engines.

              5.4. Conformity factors

              In principle, the emission limit applicable for applying the conformity factor used when performing a PEMS test, whether a PEMS test at certification or a PEMS test when checking and demonstrating the conformity of in-service engines and vehicles, should be determined on the basis of the actual GER calculated from the fuel consumption measured over