User:Milton Beychok/Sandbox: Difference between revisions

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{| class="wikitable" width=600px
<math>P_\mathrm{h} = P_0 \cdot \left(\frac{T_0 - L\cdot h}{T_0} \right)^\frac{g \cdot M}{R \cdot L}</math>
!width=28%|Refrigeration<br/>application!!Short descriptions!!width=19%|Typical<br/>refrigerants
 
which, for the parameter values below, then becomes:
 
<math>P_\mathrm h = P_0\,\cdot\bigg(\frac{T_0 - 6.5 h}{T_0}\bigg)^{5.2558}</math>
 
Given an air pollutant concentration at sea-level atmospheric pressure, the concentration at higher altitudes can be obtained from this equation:
 
 
:<math>C_\mathrm h = C_0\,\cdot\bigg(\frac{T_0 - 6.5 h}{T_0}\bigg)^{5.2558}</math>
 
{| border="0" cellpadding="2"
|-
|-
|Domestic refrigeration||Appliances used for keeping food in dwelling units||R-600a, R-134a
|align=right|where:
|&nbsp;
|-
|-
|Commercial refrigeration||Holding and displaying frozen and fresh food in retail outlets||R-134a, R-404A, R-507
!align=right| '''''L'''''
|align=left|= atmospheric temperature lapse rate = 6.5 K/km
|-
|-
|Food processing and cold storage||Equipment to preserve, process and store food from its source to the wholesale distribution point||R-134a, R-407C, R-410A, R-507
!align=right| '''h'''
|align=left|= altitude, km
|-
|-
|Transport refrigeration||Equipment to preserve and store goods, primarily foodstuffs, during transport by road, rail, air and sea||R-134a, R-407C, R-410A
!align=right| '''''g'''''
|align=left|= Earth's surface gravitational acceleration = 9.80665 m/s<sup>2</sup>
|-
|-
|Cooling of electronics||Low-temperature cooling of CMOS circuitry and<br/>other components in large computers and servers ||R-134a, R-404A, R-507
!align=right| '''''M'''''
|align=left|= Molecular weight of air = 28.9644 g/mol
|-
!align=right| '''''R'''''
|align=left|= Universal gas constant = 8.314472 J/(mol&thinsp;•&thinsp;K)
|-
!align=right| '''''P'''''<sub>&thinsp;0</sub>
|align=left|= absolute atmospheric pressure at sea level (in any selected pressure units)
|-
!align=right| '''''P'''''<sub> h</sub>
|align=left|= absolute atmospheric pressure at altitude h (in the same pressure units as '''''P'''''<sub>&thinsp;0</sub>)
|-
!align=right| '''''C'''''
|align=left|= Air pollutant concentration, in mass per unit volume at sea level atmospheric pressure '''''P'''''<sub>&thinsp;0</sub> and specified temperature '''''T'''''<sub>0</sub> (commonly 288.15 K)
|-
!align=right| '''''C'''''<sub> h</sub>
|align=left|= Concentration, in mass per unit volume at altitude '''h''' and specified temperature '''''T'''''<sub>0</sub>
|}
|}

Revision as of 01:49, 28 August 2011

which, for the parameter values below, then becomes:

Given an air pollutant concentration at sea-level atmospheric pressure, the concentration at higher altitudes can be obtained from this equation:


where:  
L = atmospheric temperature lapse rate = 6.5 K/km
h = altitude, km
g = Earth's surface gravitational acceleration = 9.80665 m/s2
M = Molecular weight of air = 28.9644 g/mol
R = Universal gas constant = 8.314472 J/(mol • K)
P 0 = absolute atmospheric pressure at sea level (in any selected pressure units)
P h = absolute atmospheric pressure at altitude h (in the same pressure units as P 0)
C = Air pollutant concentration, in mass per unit volume at sea level atmospheric pressure P 0 and specified temperature T0 (commonly 288.15 K)
C h = Concentration, in mass per unit volume at altitude h and specified temperature T0