Specific heats of liquids

Amplitude of controlled variable Output amplitude limits Cross sectional area of valve Cross sectional area of tank Controller output bias Bottoms flow rate Limit on control Controlled variable Concentration of A Discharge coefficient Inlet concentration Limit on control move Specific heat of liquid Integration constant Heat capacity of reactants Valve flow coefficient Distillate flow rate Limit on output Decoupler transfer function Error... 

Reasonably low pressures for operating temperatures Low specific heat of liquid High specific heat of vapor... 

HEAT TRANSFER SURFACE AREA, m 2 SPECIFIC HEAT OF LIQUID, kJ/kg.K WEIGHT OF BATCH LIQUID, kg. HEATING MEDIUM TEMPERATURE, K INITIAL BATCH TEMPERATURE, K ... 

Specific heat of liquid at constant pressure 0.62 Btuy(lb-°F) at 68°F 29... 

ATr = temperature rise, °F/min Pso brake horsepower at shutoff or no flow Wi = weight of liquid in pump, Ib.s Cp = specific heat of liquid in pump... 

Specific heat of liquid, BTU/lb — °F = Height of liquid (static) above ( + ) or below ( —) the centerline of the pump on discharge side, ft = Incremental height of liquid (static) above normal D level, to establish worst case condition, ft Figure 3-38... 

Equal masses of liquid A, initially at 100°C, and liquid B, initially at 50°C, are combined in an insulated container. The final temperature of the mixture is 80°C. All the heat flow occurs between the two liquids. The two liquids do not react with each other. Is the specific heat of liquid A larger than, equal to, or smaller than the specific heat of liquid B ... 

As no simple relations between the specific heats of liquids have yet been arrived at, we shall merely bring together a few generalisations from the experimental data ... 

The specific heats of liquids depend on the temperature, usually increasing, but sometimes decreasing, with rise of temperature. 

These equations are due to Clausius, and give the relation between the specific heats of liquid and vapour in the saturated complex and the ordinary specific heats at constant pressure. 

Nernst also concludes that the specific heats of liquids tend to very small values at low temperatures, since according to Tammann ( 88) liquids pass into amorphous solids at low temperatures, and the latter are subject to the ergonic distribution. 

The specific heats of liquid mixtures can be estimated, with sufficient accuracy for most technical calculations, by taking heat capacities of the components as additive. 

Specific heat of liquid = 2.78 kJkg loC thermal conductivity of liquid = 0.12 Wnrl0C 1. 

Dimplon, W. Estimating Specific Heat of Liquid Mixtures, Chemical Engineering, Oct. 2, 1972, p. 64. 

Fig. 2.7. Specific heat of liquid 4He at vapour pressure (27.58cm3/mol, o) and at about 22 bar (23.55cm3/mol, ) [26,27] compared to the specific heat of liquid 3He at vapour pressure [28,29] and of Cu.

Fig. 2.8. Specific heat of liquid 3He compared with curves for the ideal Fermi gas [30].

Fig. 2.9. Specific heat of liquid 4He at temperature closed to its normal superfluid phase transition. 

Hence the heat transport, in this case, depends on the dimension and shape of the liquid container. As we can see in Fig. 2.13, the thermal conductivity (and the specific heat) of liquid 4He decreases when pressure increases and scales with the tube diameter. At temperatures below 0.4 K, the data of thermal conductivity (eq. 2.7) follow the temperature dependence of the Debye specific heat. At higher temperatures, the thermal conductivity increases more steeply because of the viscous flow of the phonons and because of the contribution of the rotons. 

The specific heat of liquid water varies significantly with temperature. It is usually given as 4.18 J/g-°C but deviates the most near water s freezing point, 0°C and its boiling point, 100°C. 

Fig. 15. The enthalpy of liquid water calculated from the Weres-Rice model (from Ref. 64>) Fig. 16. The entropy of liquid water calculated from the Weres-Rice model (from Ref. 84>) Fig. 17. The specific heat of liquid water calculated from the Weres-Rice model (from Ref. 64>)...

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