Pipe

An inventor claims of having invented a heat engine which produces 6 kW of power for a 15 kW input while operating between energy reservoirs of 27 degC and 427 degC. Is the claim valid?

A perfect gas (air) is used as a working substance in a Carnot power cycle. At the beginning of isentropic compression, the temperature is 326K and the absolute pressure is 359 kPa. The absolute pressure at the end of the isentropic compression is 1373 kPa. For this cycle, the isothermal expansion ratio 32 is 2.0. Calculate the heat supplied.

. Two Carnot engines operate in series such that the heat rejected from one is the heat input to the other. The heat transfer from the high-temperature reservoir is 500 kJ. If the overall temperature limits are 1000K and 400 K and both engines produce equal work, determine the intermediate temperature between the two engines.

In a geothermal power plant, the mass flow rate of ground water is 400 kg/s and the quality after throttling is 17%. If the turbine power is 80 MW, what is the change in enthalpy of steam at the inlet and outlet of the turbine?

A 18,000 kW, geothermal plant has a generator efficiency and turbine efficiency of 90% and 80% respectively. If the quality after throttling is 20% and each well discharges 400,000 kg/hr, determine the number of wells required to produce if the change of enthalpy at entrance and exit of the turbine is 500 kJ/kg.

In order to predict the behavior of a small oil pump, tests are to be made on a model using air. The pump is to be driven by a 1/20-hp motor at 1800 rpm and a ¼-hp motor is available to drive the air at 600 rpm. Using specific gravity of oil at 0.912 and density of air constant at 0.076 lb/ ft3, what size model should be built?

A six cylinder, 4 stroke diesel engine with 76 mm bore x 89 mm stroke was tested at 2000 rpm in the test bed and it was found that the engine torque was 153.5 N-m with all cylinders firing but 123 N-m when one cylinder was out. The engine consumed 12.2 kg of fuel per hour with a heating value of 54,120 kJ/kg and 252.2 kg of air at 15.6°C per hour. Determine the indicated power.

. A potential waterfall for hydroelectric power plant has water available at a rate of 160 m³/s under a head of 18 m. Find the number of Francis turbines required if it runs at 120 rpm, specific speed of 350 and turbine efficiency of 80%.

Our country is embarking into the use of renewable energy sources like wind power to save energy needs. Determine the maximum power in kW that may be delivered from a 55 kph wind if the wind rotor to used has a blade diameter of 32m and the over-all conversion efficiency maybe taken as 25%. Average air pressure is 100 kPa and ambient temperature of 32°C must be assumed?

During the experiment on Charles Law, the volume of the gas trapped in the apparatus is 10000 mm³ when the temperature is 18°C. The temperature of the gas was then raised to 85°C. Determine the new volume of the gas trapped in the apparatus if the pressure exerted on the gas remained constant.

A radial-flow pump operating at maximum efficiency at a specific speed of 2500 is to deliver 260 gpm against a head of 129 ft at a rotative speed of 2100 rpm. Find the required number of stages (i.e., impellers).

. For immediate dangerous to life or health (IDHL), the maximum concentration from which unprotected persons are able to escape within _____ without escape-impairing symptoms or irreversible health.

A water tube boiler has a capacity of 1000 kg/hr of steam. The factor of evaporation is 1.3, boiler rating is 200%, boiler efficiency is 65% and heating surface area is 0.91 2 per bo.Hp. The heating value of fuel is 18,400 kcal/kg. The total coal available in the bunker is 50,000 kg. Determine the no. Of hrs. To consume the available fuel.

A 1250 kW Caterpillar Model 3512 Diesel Generator weighing 10 MT is to be installed in a Metal Closure plant in Canlubang, Laguna. The D/G specification are as follows: Weight – 10,000 kgs RPM – 1800 Engine base – 1.0 mW x 3.5 mL Foundation – 1.6 mW x 4.1 mL base dimension Particular location is on hard clay (Safe bearing load of 56 psi or 39.4 MT/m^2). What is the foundation volume required based on an e = 0.11 value. Assume concrete density of 2.4 MT/m^3 in m^3?

An adiabatic tank containing air is used to power an air turbine during times of peak power demand. The tank has a volume of 500 m3 and contains air at 1000 kPa and 500 kPa. Determine the mass remaining when the pressure reaches 100 kPa.

. A spherical ball with a diameter of 5 centimeter and whose surface is maintained at a temperature of 70 °C is suspended in the middle of a room at 2 °C. If the convection heat transfer coefficient is 15 W/m2-C and the emissivity of the surface is O.8, what is the total- heat transfer from the bal

A two-pass surface condenser is to be designed using overall heat transfer coefficient of 480 Btu/°F ft2 of outside copper tube surface. The copper tubes are to be 1 inch outside diameter with 1/16 In walls (or 7/8 in. Inside diameter). Entering circulating water velocity is to be 6 ft/s. Steam enters the condenser at a rate of 100,000 lb/ hr at a pressure of one psia and an enthalpy of 1090 Btu/ lb. Condensate leaves at saturated liquid at one psia. Circulating water enters the condenser at 85 deg. F and leaves at 95 deg F. Note: 1 psia condensate has temperature of 101.7 deg. F. Wet steam entering becomes condensate at 101.7 deg. F with hf = 69.72 Btu/lb.

A precision and electronic barometer Is used to measure an airplane's altitude by comparing the barometric pressure at a given flying altitude to that on the ground. What will be the airplane's altitude if the Captain's pilot measures the barometric pressure at 700 mm-Hg, the ground says it is at 758 mm-Hg, and the average air density is 1.19 kg/m3. g = 9.8 m/s2.

Foundation bolts of specified size should be used and surrounded by a pipe sleeve with an inside diameter of at least

You are working the 4:00 PM to Midnight shift at energy producing, coal burning steam plant. The first thing you would do when coming to work is:

One insulated wall of a new cold—storage compartment is 8m long by 2.5m high and consists of an outer steel plate 1.8 cm thick. An inner wood wall 2.25 cm thick, the steel and wood are 9.0 cm apart to form a cavity which is filled with cork. If the temperature drop across the extreme faces of the composite wall is 15½C. Calculate the heat transfer per hour through the wall and the temperature drop across the thickness of the cork. Take the coefficients of thermal conductivity for steel, cork and wood as 45, 0.045, and 0.18 W/m-K respectively.

. In accordance with recommended practice, a sample of boiler water for pH analysis should be taken:

During takeoff in a spaceship, an astronaut is subjected to acceleration equal to 5 times the pull of the earth's standard gravity. If the astronaut is 180 lbm and the takeoff is vertical, what force does he exert on the seat?

The sound power level Of a VAV Box (Variable Air Volume) depends mainly on Volume flow of supply air for a specific size box, configuration of the VAV box, flexible ducts, diffusers and what other factor?

A 4 meter x 5 meter x 6 meter special storage room is to be heated by a baseboard resistance heater. It is desired that the resistance heater be able to raise the air temperature in the special storage room from 7 °C to 23 °C within 15 minutes. Assuming no heat losses from the special storage room and an atmospheric pressure of 100 kpa, determine the required power of the resistance heater. Constant specific heats at room temperature to be assumed

A pressure cooker operates by cooking food at a higher pressure and temperature than is possible at atmospheric conditions. Steam is contained in the sealed pot, with vent hole in the middle of the cover, allowing steam to escape. The pressure is regulated by covering the vent hole with a small weight, which is displaced slightly by escaping steam. Atmospheric pressure is 100 kPa, the vent hole area is 7-mm2, and the pressure inside should be 250 kPa. What is the mass of the weight?

The applications and joining methods for this pipe are very similar to those for PVC. However, this pipe can be used for hot water (up to 180 °F) in a pressurized system (up to 100 psi).

What other factor will the sound power level of a Variable Air volume Box depends other than the volume flow of supply air for a specific size box, configuration of the variable air volume box, flexible ducts and diffusers?

A college student living in a dormitory room of 4 meters x 6meters x 6meters turns on her 150 watts electric fan before she leaves the room on a summer day, hoping that the room will be cooler when she comes back in the evening. Assuming all the doors and windows are tightly closed and disregarding any heat transfer through the walls and the windows, determine the temperature in the room when she comes back 10 hours later. Use specific heat values at room temperature, and assume the room to be at 100 kpa and 15 C in the morning when she leaves.

. Piping installation crossing an open space that affords passageway in any building shall be not less than ____ above he floor unless the piping s located against the ceiling of such space and permitted by the authority having jurisdiction.

The refrigerant used in steam jet is:

A V—type 3.0 liter, 5—cy1inder, 4—stroke cycle SI engine, with a volumetric efficiency of 82%, operates at 3000 RPM using gasoline with a? = 0.91. Bore and stroke are related as S = 1. 08B. At a certein point in the engine cycle, the gas temperature in the combustion chamber is Tg = 21000C while the cylinder wall temperature is TW = 1900C. Viscosity, and Thermal conductivity, of gases (air at 11450C) ?g= 5.21x10-5 kg/m—sec, kg = 0.090 W/m-K respectively. Convection heat transfer coefficient of c1 = 0.035 and c2 = O. 08. Compute the approximate convection heat transfer rate to the cylinder wall at this instant.

As a rule of thumb, for a specified amount of compressed air, the power consumption of the compressor decreases by _____ for each 3 °C drop in the temperature inlet air to the compressor.

A “Fairbank Morse” vertical turbine pump draws water at a head of 110 meters and a discharge rate of 550 liters per second. What is the brake horsepower input if the pump efficiency is at 70 percent?

A fresh supply of 50 kilograms chicken at 6 °C contained in a box is be frozen to -18°C in a electric freezer. What will be the amount of heat that needs to be removed? The latent heat of the chicken is 247 KJ/kg, and its specific heat is 3.32 KJ/kg-C above freezing and 1.77 KJ/kg-C below freezing. The container box is 1.5 kilograms, and the specific heat of the box material is 1.4 KJ/kg-C. And the freezing temperature of chicken is -2.8 °C.

In order to cool 1000 kilograms (1 ton) of water at 20 degC in an Armaflex insulated steel tank, a man pours 80 kilograms of ice at -5 degC into the water. Determine the final equilibrium temperature in the Armaflex insulated steel tank. The melting temperature and the heat of fusion of ice at atmospheric pressure are 0 deg C and 333.7 kJ/kg, respectively.

. In a new model Francis turbine, the pressure gage leading to the turbine casing reads 380 kPa. The velocity of water entering the rubine is 8 meters per second, if net head of the turbine is 45 m, what is the distance from center of spiral casing to the tailrace?

An adiabatic tank containing air is used to power an air turbine during the times of peak power demand. The tank has a volume of 500 cu. M and contains air at a pressure of 1000 kPa and a temperature of 500 degK. What is the temperature at this instant?

A 300 x 400 mm branch duct leaves a 300 mm x 600 mm main duct at an angle of 60 deg. The air temperature is 20 deg C. The dimensions of the main duct remain constant following the branch. The flow rate upstream is 2.7 cu m/sec. What is the pressure downstream in the main duct. Note: at 20 deg C, P = 1.2041 kg/cu m.

C8H18 fuel is burned with 25 percent excess. Calculate the weight of air needed including moisture if air is at a temperature of 25 deg C and 60 percent RH (w = 0.012)

In a Geothermal power plant hot groundwater from a hot spring is used to power a heat engine. If the groundwater is at 95 deg C, estimate the maximum power output if the mass flow rate of groundwater is 0.2 kg/sec. Atmosphere is at 20 deg C.

A small drop of water at 80 ½F is in contact with the air and has diameter of 0.02 in. If the pressure within the droplet is 0.082 psi greater than the atmosphere, What is the value of the surface tension?

A fresh supply of 50 kilograms chicken at 6 deg C contained in a box is to be frozen to -18 deg C in a GE electric freezer. What will be the amount of heat that needs to be removed? The latent heat of the chicken is 247 kJ/kg and its specific heat is 3.32 kJ/kg-C above freezing and 1.77 kJ/kg-C below freezing. The container box is 1.5 kilograms, and the specific heat of the box material is 1.4 kJ/kg-C, and the freezing temperature of chicken is -2.8 deg C.

A Japan made two-stage, double acting compressor is to deliver 90 lb/min of air from a pressure of 14.3 psia and at a temperature of 90 deg F to a final pressure of 185 psia. The normal barometer reading is 29.8 in-Hg and the temperature is at 80 deg F. The pressure drop in the intercooler is 3 psi and the speed is 210 rpm and pV1.34 = C during compression and expansion process. The clearance for both cylinders are 5 per cent respectively. The temperature of the cooling water was increased by 18 deg F. Compute for the volume of free air.

A pump will be installed below the reservoir water surface with a required net positive suction head (NPSHR) of 50 ft. The barometric pressure is 14.3 psia, and the vapor pressure is 0.5 psia. Assume friction losses in the intake piping are 5 ft. Find the maximum allowable elevation of the pump relative to the water surface intake to avoid cavitation.

When a man returns to his wall-sealed house on a summer day, he finds that the house is at 32°C. He returns on the air conditioner which cools the entire house to 20°C in 15 minutes. If COP is 2.5, determine the power drawn by the air conditioner. Assume the entire mass within the house is 800 kg of air for which cv = 0.72 kJ/kg-K, cp = 1.0 kJ/kg-K.

An Atlas-Copco oil-free air compressor Model ZT-22 is providing sterile air to a soft drinks bottling plant. The weight of the compressor 1120 kgs. What is the minimum volume of the foundation required as PSME Code 2003. (Assume concrete density at 2.4 MT/m3) in m3?

What is the BoHP required for a hotel facility requiring a steam load of 7800 kgs/hr for its hot water and laundry facility? Assume factor of evaporation, FE =1.0.

In a flour mill, a pneumatic unloader unloads wheat from barges with a bulk density of 770 kgs/cu.m. From the roots blower catalog, the conveying velocity required for bulk density of 720 kgs/m3 is 1,882 mtr/min while the conveying velocity required for a bulk density of 800 kgs/m3 is 1,981 mtr/min. What would be the appropriate conveying velocity for a bulk density of 770 kgs/m3?

With three different quantities x, y, and z of the same kind of liquid of temperatures 9, 21 and 38°C respectively, it is found that when x and y are mixed together the resultant temperature is 17°C and when y and z are mixed together the resultant temperature is 28°C. Find the resultant temperature if x and z were mixed.

A plate-type solar energy collector with an absorbing surface covered by a glass plate is to receive an incident radiation of 800 W/m2. The glass plate has a reflectivity of 0.12 and a 56 transmissivity of 0.85. The absorbing surface has an absorptivity of 0.90. The area of the collector is 5 m2. How much solar energy in watts is absorbed by the collector?

What should be the cooling requirement due to emission of human body to maintain a comfortable temperature in a dance hall with an attendance of 1500 people of which 75% of the people will be dancing and others will be seated? Take note that an adult will give off 71.8 W of sensible heat while engaging in moderate dancing, and 57.1 W of sensible heat while sitting. The latent heat emissions for similar situations are 177.3 W for dancers and 45.5 W for sitters.

An appliance center dealer advertises that he has just received a shipment of electric resistance heaters with 100% efficiency to be used for residential buildings. If it is assumed that the indoor temperature is 21 degC and outdoor temperature is 10 degC, calculate the second law efficiency of these heaters.

. A vertical rectangular gate 1.5m wide and 3m high is submerged in water with its top edge same level as the water surface, determine the hydrostatic force acting on one side of the gate and its eccentricity.

An iceberg having specific gravity of 0.92 is floating on salt water of specific gravity of 1.03. If the volume of ice above the water surface is 22003 , what is the total volume of the ice?

Two Carnot engines operate in series such that the heat rejected from one is the heat input to the other. The heat transfer from the high temperature reservoir is 500 kJ. If the overall temperature limits are 1250 K and 420 K and both engines produce equal efficiency, determine the intermediate temperature between the two engines.

In a geothermal power plant, the mass flow rate of ground water is 400 kg/s and the quality after throttling is 17%. If the turbine power is 80 MW, what is the change in enthalpy of steam at the inlet and outlet of the turbine?

A 18,000 kW, geothermal plant has a generator efficiency and turbine efficiency of 90% and 80% respectively. If the quality after throttling is 20% and each well discharges 400,000 kg/hr, determine the number of wells required to produce if the change of enthalpy at entrance and exit of the turbine is 500 kJ/kg.

In order to predict the behavior of a small oil pump, tests are to be made on a model using air. The pump is to be driven by a 1/20-hp motor at 1800 rpm and a ¼-hp motor is available to drive the air at 600 rpm. Using specific gravity of oil at 0.912 and density of air constant at 0.076 lb/ ft3, what size model should be built?

A 30 HP centrifugal pump is used to deliver 70 cfm water. Calculate the number of stages needed if each impeller develops a 21ft head.

A potential waterfall for hydroelectric power plant has water available at a rate of 160 3/ under a head of 18 m. Find the number of Francis turbines required if it runs at 120 rpm, specific speed of 350 and turbine efficiency of 80%

A 6 MW steam generator power plant has a full load steam rate of 8 kg/kW-hr. Assuming that no-load steam consumption as 15% of full-load steam consumption, compute the hourly steam consumption at 85% load in kg/hr.

A 35% solution leaves the absorber and 30% solution enters the absorber. The heat removed from the absorber by cooling water is 547.6 Btu and ammonia is superheated by 10°. Find the pound per pound of ammonia gas from the evaporating coils.

A Francis turbine is to be operated at a speed of 600 rpm and with discharge of 4 m^3 /s. If 1 = 0.6 m, β = 110°, and the blade height B is 10 cm, what should be the guide vane angle 1 for nonseparating flow condition at the runner entrance?

A Coil has an inlet temperature of 60℉ and outlet of 95℉. If the mean temperature of the coil is 110℉, find the bypass factor

When a man returns to his well-sealed house on a summer day, he finds that the house is at 32°C. He turns on the air conditioner, which cools the entire house to 20°C in 15 min. If COP of the air conditioner system is 2.5, determine the power drawn by the air conditioners. Assume the entire mass within the house is equivalent to 800 kg of air for which c = 0.72 kJ/kg -°C.

A diesel electric plant supplies energy for Meralco. During a 24 hr Period, the plant consumed 200 gallons of fuel at 28°C and produced 3930 Kw-hr. Industrial fuel used is 28°API and was purchased at P5.50 per liter at 15.6°C. What should the cost of fuel be produce one kw-hr.?

A pump in a municipality’s water-supply system receives water from the filtration beds and pumps it up to the top of a water tower. The tower’s height is 35 m, and the inlet piping to the pump is 2 m above the pump’s intake. The water temperature is 20 C, measured at both the inlet and the discharge from the pump. The mass flow rate through the pump is 100 kg/s, the diameter of the inlet piping is 25 cm, and the diameter of the discharge piping is 15 cm. Determine the power required by the pump.

Consider a person standing in a breezy room at 20°C. Determine the total rate of heat transfer from this person if the exposed surface area and the average outer surface temperature of the person are 1.6 m2and 29°C, respectively, and the convection heat transfer coefficient is 6 W/m2 with emissivity factor of 0.95.

A student living in a 4 m x 6 m x 6 m dormitory room turns on her 150 watts fan before she leaves the room on a summer day, hoping that the room will be cooler when she comes back in the evening. Assuming all the doors and windows are tightly closed and disregarding any heat transfer through the walls and the windows, determine the temperature in the room when she comes back 10 hours later. Use specific heat values at room temperature, and assume the room to be at 100 kPa and 15°C in the morning when she leaves.

Consider a refrigerator whose 40 watts light bulb remains on continuously as a result of a malfunction of the switch. If the refrigerator has a COP of 1.3 and the cost of electricity is 8 cents per kW-hr, determine the increase in the energy consumption of the refrigerator and its cost per year if the switch is not fixed.

During takeoff in a spaceship, an astronaut is subjected to acceleration equal to 5 times the pull of the earth’s standard gravity. If the astronaut is 180 lbm and the takeoff is vertical, what force does he exert on the seat?

Based on industry practice, for a specified amount of compressed air, the power consumption of the compressor decreases by _____ for each 3½ drop in the temperature inlet air to the compressor.