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# Thermodynamics Steam Enthalpy Quiz

Created by
@RoomierIambicPentameter

### What is the factor of evaporation for the boiler producing 1591 kg of steam per hour?

• 1.3
• 1.15
• 1.2 (correct)
• 1.4
• ### If one boiler has an efficiency of 65%, what is the efficiency of the other boiler producing 1364 kg of steam per hour?

• 70%
• 65%
• 55%
• 60% (correct)
• ### How many kilograms of steam are produced by both boilers combined per hour?

• 2950 kg
• 2955 kg (correct)
• 1500 kg
• 2900 kg
• ### What is the heating surface area for boilers given in the text?

<p>0.91 m per bo.Hp</p> Signup and view all the answers

### If the heating value of coal is 7,590 kcal/kg, how many hours can the coal in the bunker run the boilers?

<p>350.35 hrs</p> Signup and view all the answers

### What is the pressure at 12000 ft altitude if air is incompressible and atmospheric air is 14.7 psia at sea level?

<p>5.467 psia</p> Signup and view all the answers

### What is the final enthalpy of the mixture when 1.5 kg of wet steam at a pressure of 73 psi and dryness 0.95 is blown into 18.5 gallons of water of 54°F?

<p>84.80 kJ/kg</p> Signup and view all the answers

### What is the final volume of the steam when wet saturated steam at 16 bar is expanded to a pressure of 0.1 bar with a dryness fraction of 0.9?

<p>463.74 liters</p> Signup and view all the answers

### If 1.5 kg of wet steam at a pressure of 5 bar and dryness 0.95 is mixed with 70 liters of water at 12°C, what is the final enthalpy of the mixture?

<p>74.80 kJ/kg</p> Signup and view all the answers

### After throttling wet saturated steam at 16 bar to a pressure of 8 bar, what is the dryness fraction of the resulting steam?

<p>1.0498</p> Signup and view all the answers

### What is the fuel consumption per BHP-hour of a Caterpillar diesel engine using fuel oil of 28 API gravity if it is rated at 650 BHP?

<p>0.75 lb/BHP-hr</p> Signup and view all the answers

### What is the head water elevation in the hydro-electric plant if the net head is 30 m and the head loss accounts for 5% of the gross head?

<p>785.25 m</p> Signup and view all the answers

### What is the water power of the hydro-electric plant with a flow rate of 15 m^3/s and a head loss of 10% of the gross head, given tailwater at 150 m and headwater at 200 m?

<p>7,621.65 kW</p> Signup and view all the answers

### In a 5 m x 1 m channel with a water velocity of 6 m/s, what is the annual energy produced in kilowatt-hours with a net head of 120 m and an efficiency of 80%?

<p>247,497,582 kW-hrs</p> Signup and view all the answers

### If water flows at 10 m/s in a penstock with a cross-sectional area of 1 m^2 and the turbine efficiency is 87%, what is the turbine output with a net head of 30 m?

<p>2,501.55 kW</p> Signup and view all the answers

### For a 83 MW power plant with an average load of 35,000 kW and a load factor of 65%, what is the reserve over peak?

<p>29.15 MW</p> Signup and view all the answers

### If a power plant has a use factor of 48.5% and a capacity factor of 41.9%, how many hours did it operate during the year?

<p>7,658.23 hrs</p> Signup and view all the answers

## Study Notes

### Boiler Efficiency and Steam Production

• The factor of evaporation for a boiler producing 1591 kg of steam per hour can be calculated.
• A boiler with an efficiency of 65% produces 1591 kg of steam per hour, while another boiler producing 1364 kg of steam per hour has a different efficiency.

### Steam Properties and Expansion

• Wet steam at a pressure of 73 psi and dryness 0.95, when mixed with 18.5 gallons of water at 54°F, results in a specific final enthalpy.
• Wet saturated steam at 16 bar, when expanded to a pressure of 0.1 bar with a dryness fraction of 0.9, has a specific final volume.

### Fuel Consumption and Cost

• A Caterpillar diesel engine with a rating of 650 BHP has a fuel consumption per BHP-hour.
• The cost of running the Caterpillar diesel engine for an hour at full power is P 7.95 per liter.

### Coal and Bunker Capacity

• The heating value of coal is 7,590 kcal/kg.
• The level capacity formula of a suspension bunker involves its width, depth, and length.
• The density of coal is mentioned in the text.

### Thermal Efficiency and Heat Energy

• The heat energy supplied per kg at constant pressure is given by Cp = 1.055 kJ/kg-K.
• A 1 MW diesel electric plant with a brake thermal efficiency of 36% and a generator efficiency of 89% generates a specific amount of heat.

### Engines and Heat Generation

• A 305 mm x 457 mm four-stroke single-acting diesel engine is rated at 150 kW at 260 rpm and has a specific brake thermal efficiency.
• The heat lost per 100 ft of insulated pipe can be calculated based on the temperature of the outer surface of the cork.
• The heat generated per minute at the bearings of a shaft can be calculated based on the journals' diameter, speed, coefficient of friction, and average load.

### Refrigeration and Carnot Cycle

• In a reverse Carnot cycle that extracts energy from a lake to heat a house, the temperature of the lake can be calculated.

### Pressure and Flow Rate

• The pressure of an oxygen cylinder with a volume of 2.3 ft³ at 21°C can be calculated.
• The speed of the journals of a shaft can be calculated based on their diameter, coefficient of friction, and average load.

### Hydro-Electric Plant

• The head water elevation in a hydro-electric plant can be calculated based on the net head and head loss.
• The water power of a hydro-electric plant can be calculated based on the flow rate and head loss.
• The annual energy produced in a hydro-electric plant can be calculated based on the net head, efficiency, and flow rate.

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## Description

Test your knowledge on calculating enthalpy of steam mixtures and superheated steam. Solve problems involving wet steam, pressure, temperature, and enthalpy to find the final enthalpy of a mixture. Ideal for students studying thermodynamics and steam properties.

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