Food and Health Bureau A Rooftop Helipad at the Proposed New Block

at Queen Mary Hospital

Environmental Impact AssessmentAppendix 3.2

Helicopter Emission Calculation

Helicopter Information

Helicopter Model Airbus H175

Engine Type Twin Engine Turboshaft

No. of Engine 2 Note 1

Max. SHP of Engine 1776 SHP

Fuel Sulphur Content by Weight 0.3 %

SO2 Emission Rate for Idling Mode

Time in Mode (Idling) 300 s

Estimated SHP 106.6 SHP Note 2

Fuel Flow per Engine 0.0235 kg/s Note 3

SO2 Emission Rate 0.282 g/s Note 4

Averaged SO2 Emission Rate in an Hour 2.4E-02 g/s Note 5

SO2 Emission Rate for Hovering (Approach) and Touchdown Mode

Time in Mode (Hovering (Approach) + Touchdown) 8 s

Estimated SHP 1776 SHP Note 2, 6

Fuel Flow per Engine 0.106 kg/s Note 3

SO2 Emission Rate 1.269 g/s Note 4

Averaged SO2 Emission Rate in an Hour 2.8E-03 g/s Note 5

SO2 Emission Rate for Hovering (Take-off) and Lift-off

Time in Mode (Hovering (Take-off) + Lift-off) 8 s

Estimated SHP 1776 SHP Note 2

Fuel Flow per Engine 0.106 kg/s Note 3

SO2 Emission Rate 1.269 g/s Note 4

Averaged SO2 Emission Rate in an Hour 2.8E-03 g/s Note 5

SO2 Emission Rate for Take-off or Approach Mode Along the Flight Paths

Time in Mode (Take-off / Approach) 60 s

Estimated SHP 1776 SHP Note 2, 6

Fuel Flow per Engine 0.106 kg/s Note 3

SO2 Emission Rate 0.635 g/s Note 4

Averaged SO2 Emission Rate in an Hour 0.0212 g/s Note 5

Effective area of the line source 1480.3 m2

Note 7

Averaged SO2 Emission Rate in an Hour 1.4E-05 g/s/m2

Note:

1. Information is provided by GFS.

7. The width of the line source is assumed to be the same as the width of H175, 2.85m. Length is 519.4m.

2. As advised by GFS, the power for take-off per engine would be 100% of the max power. For Idling, 6% of max power per engine was employed as per

Table 4 of Guidance on the Determination of Helicopter Emissions (GDHE) (Swiss confederation 2015).

6. It is assumed 100% engine power for conservative approach

3. The estimated fuel flow for the proposed helicopter is based on the empirical formula as listed in Section 3.2, Fuel Flow for Engines above 1000 SHP,

GDHE.

5. There will be < 1 helicopter operation in a day. For conservative approach, the emission rate for 1 helicopter was applied to each hour of a year in the

model in order to obtain the worst concentration.

4. Emission rate for each engine = Fuel flow x Sulphur content x 2

Food and Health Bureau A Rooftop Helipad at the Proposed New Block

at Queen Mary Hospital

Environmental Impact Assessment

Summary of Model Inputs

X1 Y1 X2 Y2Exhaust

Diameter, m

Exhaust

Height, mPD

1 Exhaust

Velocity,

m/s

1 Exhaust

Temp, KSource Type

Emission

Rate, g/s

Emission

Rate,

g/m2/s

H1 831567.3 814800.3 NA NAHovering (Approach) +

Touchdown8 0.3 301.9 6.0 373.2 Point 2.8x10

-3 NA

H2 831567.3 814800.3 NA NA Idling 300 0.3 299.4 6.0 373.2 Point 2.4x10-2 NA

H3 831567.3 814800.3 NA NA Hovering (Take-off) and Lift-off 8 0.3 301.9 6.0 373.2 Point 2.8x10-3 NA

TO/AP_S 831567.3 814800.3 831495.0 814286.02 Take-off or Approach Mode

Along the Flight Path (South)60 NA 301.9 NA NA Line NA 1.4x10

-5

TO/AP_W 831047.9 814800.3 831567.3 814800.32 Take-off or Approach Mode

Along the Flight Path (West)60 NA 301.9 NA NA Line NA 1.4x10

-5

Note:

2. As advised by GFS, helicopter operations are expected to be in one-way-direction as one of the recommended noise mitigation measures. The arrival flight and departure flight shall be from north to south and vice versa.

NA: Not applicable in the model

1. Assumed as the minimum exhaust velocity and temperature as required by the air pollution control license for conservative approach. As advised by GFS, the exhaust velocity and temperature for turboshaft engine is considered to be higher than assumed values.

Model ID

Coordinates, m

Time, s

Parameters input in AERMOD

Emission Point Description

Food and Health Bureau A Rooftop Helipad at the Proposed New Block

at Queen Mary Hospital

Environmental Impact Assessment

Summary of Surface Parameters

PATH Grid

Sector, degree

(clockwise) Land use2 Roughness, m

3 Albedo

4 Bowen ratio

0 - 2101 Forest/Grassland 0.065 0.185 0.8

210 - 300 Urban 1 0.18 1.5

300 - 3601 Forest/Grassland 0.065 0.185 0.8

Note:

1. Parameters for grassland were adopted for conservative approach.

2. Average seasonal categories: 1, 2, 3 & 5 as per Table A-3 of USEPA's AERSURFACE user guide.

3. Average seasonal categories: 1, 2, 3 & 5 as per Table A-1 of USEPA's AERSURFACE user guide.

4. Average seasonal categories: 1, 2, 3 & 5 as per Table A-2 of USEPA's AERSURFACE user guide.

36, 28