Water cooling curve

Example. A water-cooled unit with an evaporator temperature of-40°F will require 3 horsepower/ton of refrigeration. A ton of refrigeration is equal to 12,000 BTU/hr. Here are equations for these curves in the fonn ... 

On a sheet of graph paper, make a graph of time versus temperature for your after cooling data. You should have four points each for sand and water. This graph is called a cooling curve. Make sure you place the independent variable on the x-axis. 

Interpreting Data Discuss the differences in the cooling curves for sand and water. Explain their significance. 

Figure 24.7 The limiting cooling water composite curve. (From Kim J-K and Smith R, 2001, Chern Eng Sci, 56 3641, reproduced by permission of Elsevier Ltd.)...

Sketch the cooling curve for water and identify its key features. 

Fig. 2.42 Condensation capacity of the condenser (surface area avaiiabie to condensation 1 rrf) as a function of intake pressure pp, of the water vapor. Curve a Cooling water temperature 12°C. Curve b Temperature 25 X. Consumption in both cases 1 mVh at 3 bar overpressure.

A cooling curve for water can be graphed by taking heated water and placing it in a Styrofoam cup and taking temperature reading at... 

DSC. Figure 1 shows DSC cooling curves of the water-NaLS system having various Wc s from 0.46 to 2.31 g/g. When a sample with water is cooled from 50°C at the rate of 10°C/min, a broad peak (P ) is observed initially, followed by a sharp peak representing crystallization of water (P/). However, as shown in Figure 1, only P is observed if Wc is lower than ca. 0-5 g/g. 

Figure 1. DSC cooling curves of the water-NaLS system with various water contents, Wc(g/g).

FIGURE 8.9 The phase diagram for water and the cooling curve for a sample initially at point A. The sample cools at constant pressure through B to ice at C. The pause in the decline of the cooling curve at B is due to the release of heat when the liquid freezes. 

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