SDB系列空调管道直燃燃烧器使用说明书。

-11-APPENDIX A Calculation Method &Examples

SUNSRAYS normally uses the following formula to calculate the required net heat input:

Q (kW)=Airflow (Nm3/s)x Temperature rise (ºC)x Air Density x Specific Heat of Air

or

Q (Btu/h)=Airflow (scfh)x Temperature rise (ºF)x Air Density x Specific Heat of Air

The required gross gas input =Required net heat input/0.92

The gross gas input ÷firing rate per 12”(305mm)section will determine the required burner length.Minimum section length =6”(150mm).

Example:

A.Airflow =5Nm3/s

B.“Air on”temperature =-5ºC

C.“Air off”temperature

=25ºC D.Preferred firing rate =600,000Btu /176kW)per 12”(305mm)section

Required net heat input =181kW

Required gross gas input =197kW

Number of 6”(152.5mm)sections =197÷176=1.12x 2=2.24which is “rounded up”to 3.

Total burner length =3x 6”=18”(or 3x

152.5mm =458mm)The required net profile area (excluding the burner)=Airflow/Profile velocity (determined by burner firing rate)Net Profile Area (excluding burner)=5Nm3/s/14.7m/s =0.34m2

Total Profile Area (including burner)=Net Profile Area +Burner Profile Area (0.03m2/6”burner section)=0.34+0.09=0.43m2

Required width of the profile opening =Total burner length +100mm (4”)=558mm (rounded to 560mm)Required height of the profile opening =Total Profile Area/Required Width of Profile Opening

=0.43x 106/558=770mm

Minimum duct width =Burner length +305mm (152.5mm

at either side)=763mm (rounded to 770mm)Minimum duct height =Height of profile opening +200mm (8”)=970mm