Data for steady-state operation of a vapor-compression refrigeration cycle with propane as the working fluid are given in the table below. The states are numbered as in Fig. 10.3. The mass flow rate of refrigerant is 8.42 lb/min. Heat transfer from the compressor to its surroundings occurs at a rate of 3.5 Btu per lb of refrigerant passing through the compressor. The condenser is water-cooled, with water entering at 658F and leaving at 808F with negligible change in pressure. Sketch the T-s diagram of the cycle and determine
(a) the refrigeration capacity, in tons.
(b) the compressor power, in horsepower.
(c) the mass flow rate of the condenser cooling water, in lb/min.
(d) the coefficient of performance.
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drops through the evaporator or condenser, and the
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State
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p (lbf/in.2)
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T (8F)
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h(Btu/lb)
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refrigerating capacity is 1 ton. Plot refrigerant mass flow rate,
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1
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38.4
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0
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193.2
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in lb/min, coefficient of performance, and refrigerating
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2
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180
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120
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229.8
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efficiency, versus TC ranging from 408F to 2258F if the
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3
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180
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85
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74.41
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refrigerant is
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4
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38.4
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0
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74.41
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