Gas meter firing rate calcs

Discussion in 'Computer Support' started by Martik, Nov 30, 2006.

  1. Martik

    Martik Guest

    My gas meter is metric with one of the dials calibrated to .01 cu meters. If
    one revolution takes 16 secs, what is the gas consumption rate according to
    the table below?

    I get 80,000btu as follows:

    1 cu ft = 12^3 cu in or 1728
    1 cu meter = 39.37^3 cu in or 61023
    ..01 cu meters = 610 cu in
    therefore to extrapolate to 1 cu ft: multiply 16 secs by = 1728/610 or 2.8
    which is 45 secs

    Does this make sense?

    -------------------------------------------------------------

    Checking the Firing Rate -"Clocking the Meter"

    Checking the firing rate of a furnace is a very important element of the
    installation procedure. Over-firing can cause premature heat exchanger
    failure. This is done by measuring the time it takes to consume 1 cubic
    foot of gas.

    When performing this procedure it is important to activate the furnace for
    about 10-15 minutes, and all the other gas appliances are turned off.
    Adjust inlet gas pressure to between 5 and 7 inches water column then time
    the meter for 2 revolutions and then divide by 2 to get the time for one
    revolution. Need to check meter size (1 CuFt or 10 CuFt).

    The following table shows approximate gas consumption (measured in cubic
    feet per hour), and the gas input (measured in Btu/Hr), based on Natural gas
    whose caloric value ranges from 900 to 1050 Btu/cu. ft. We are assuming
    1000 Btu/cu. ft.

    Gas Input (Btu/Hr) =
    (Caloric Value of Gas x 3600) / Meter Time (seconds)

    This chart assumes a 1 CuFt meter size

    Seconds
    per cubic
    feet Consumption
    cubic feet
    per hour Gas input
    btu/hr
    @ 1000 btu/cu ft
    20 180 180,000
    22 164 164,000
    24 150 150,000
    26 138 138,000
    28 129 129,000
    30 120 120,000
    32 113 113,000
    34 106 106,000
    36 100 100,000
    38 95 95,000
    40 90 90,000
    42 86 86,000
    44 82 82,000
    46 78 78,000
    48 75 75,000
    50 72 72,000
    52 69 69,000
    54 67 67,000
    56 64 64,000
    58 62 62,000
    60 60 60,000
    62 58 58,000
    64 56 56,000
    66 54 54,000
    68 53 53,000
    70 51 51,000
    72 50 50,000
    74 48 48,000
    76 47 47,000
    78 46 46,000
    80 45 45,000
    82 44 44,000
    84 43 43,000
    86 42 42,000
    88 41 41,000
    90 40 40,000
     
    Martik, Nov 30, 2006
    #1
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  2. Martik

    SgtMinor Guest

    I got 81,592 Btu/hr, as follows:
    1 hour = 3600 seconds, divided by 16 seconds per revolution = 225
    revolutions, which equals 2.25 cubic meters.
    1 cubic meter = 35.31 cubic feet.
    1 cubic foot contains approximately 1027 Btu.
    Thus 2.25 x 35.31 x 1027 = 81,592.
    If you rate a cubic foot at 1,000 btu, consumption = 79,448.
     
    SgtMinor, Dec 1, 2006
    #2
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  3. Martik

    Martik Guest

    That makes sense and no tables required!

    Thanks
     
    Martik, Dec 1, 2006
    #3
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