Higher heating value errors

Material Measured higher heating value (MJ/dry kg) Calculated higher heating value (MJ/dry kg) Error (%)... 

The relationship is evidently a good fit with at most 5 per cent error in predicting the higher heating value of a compound of specified C,H and 0 composition. The greatest error is obtained for carbon monoxide where 4208 J/g is calculated when the true value is 10110 J/g. 

In Table 1 are assembled the heats of adsorption for various absorbate systems on different substrates determined via isosteric heat measurement as well as calorimetric measurements. In some cases the heat of adsorption for one system has been measured using different techniques. This allows an estimation of the error involved in using those values based on different measurements. It is clear that the value for CO adsorption on Fe, for example, is considerably higher than values for other CO-adsorbate systems. In order to judge this, it must be understood that at room temperature CO partly dissociates on polycrystallinc Fe which contributes to the observed calorimetric value. This is a useful reminder that consecutive processes have to be considered in calorimetric measurements. 

Comparing the literature data, the 3C polytype should have a slightly higher specific heat Table I. From the data presented here, several cases stand out where the specific heat values are roughly the same for similar amounts of SiC. With the actual difference of the pure silicon carbide polytypes being 0.002, 1/ g K, differences in the actual data are most likely contained within the experimental error of this measurement. The specific heat should therefore not have a great impact on the thermal conductivity of these materials with respect to their respective polytypes. 

The use of surfaee mount parts is widespread. Surfaee mount parts ean rid themselves of heat only through their leads whieh are soldered to a printed eireuit board. The thiekness and surfaee area of the eopper island beeome the heatsink system. The thermal resistanees in surfaee mount deviees are mueh higher, therefore their designs have mueh less margin and room for error. Table A-3 has nominal values for thermal resistanees of eommon surfaee mount paekages. Please refer to the individual part data sheet for the exaet value. 

For this low-temperature and -pressure range, any gas density may quickly be calculated. Error here is less than 3% in every case checked. What about higher temperatures and pressures Aren t these higher values where all concerns rest Yes, most all process unit operations, such as fractionation, separation, absorption stripping, chemical reaction, and heat exchange generate and apply these higher-temperature... 

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