📝 [PIPE] QB ID: 0418 | PIPE Elements No. 12

Which statement is correct on the effect of increasing condensing pressure in a vapor compression system?

Freezing method utilizes the combined effects of low temperature and high air velocity to produce a high rate of heat transfer from product is called:

A component installed a refrigeration system to ensure that no liquid enters the compressor and subcooled the liquid from condenser to prevent bubbles of vapor from impending the flow of refrigerant through expansion valve is called:

Refrigerant used in steam-jet refrigeration is:

Which refrigerant is completely miscible with oil:

Ammonia is not used in domestic refrigeration and comfort air-conditioning because:

Refrigerants 22 (R22) which is an HCFC, has 1/20th the ozone depletion potential (ODP) of R11 and R12. Hence, it can be continue to be used for quite sometime. However, all these have global warming-potential (GWP). Because of this, R22 will have to be phased out by year:

Which of the statements is incorrect regarding the functions of the liquid receiver?

A shutoff valve that is actuated by an electromagnetic coil is called:

Which of the following statement is not false?

Refrigeration system of 2 tons capacity. Which of the following statements is correct?

It states that when two bodies are in thermal equilibrium with a third body. They are in thermal equilibrium with each other and hence are at the same temperature.

It states that the change of internal energy of an ideal gas is a function of only the temperature change

The energy or stored capacity for performing work possessed by a moving body, by virtue of its momentum.

The volume between the engine head and the piston when the piston is at the top dead center

The process in which both the intake and exhaust valves are closed, and the air-fuel mixture is processed by the upward piston movement.

Is a term expressing the combination of internal molecular energy, expansion work and flow work.

The combination of two refrigerants which cannot be separated by distillation process.

R-600 is what refrigerant?

The measure of the ability of a goal to withstand exposure to the environment elements without excessive crumbling.

A type of coal that tends to break apart as it burns thereby exposing the unburned coal to the combustion air.

A type of coal that produced a fused coal mass as it burns.

A combustible coal content that produces a major atmospheric pollutant consequently, it is important that coal has a low percentage of this component.

The sum of the pressure head and velocity head.

Which of the following statement is/are true regards to the first law of thermodynamics for a change in state of a control mass

Which of the following statements is/are true with regards to heat and work.

The height of the surface of the water above the gage point

The head required to produced a flow of the water.

The dynamic pressure of the liquid at pump section less the corresponding to the temperature at the same point, converted to liquid.

The algebraic difference of the discharge and suction heads.

The transfer of the heat energy from exhaust gases to compressed air flowing between the compressor and combustion chamber.

The removal of heat from compressed air between stages of compression.

As a general rule, the cooling water side of the condenser should be schedule for inspection for every:

If the compressor runs continually, the cause might be the:

If the temperature in the icebox is too high, the trouble could be:

If frost forms on the cylinders, the cause would be:

The most likely cause of high superheat would be:

Short-cycling means that the machine:

If the cooling water to the condenser should suddenly fail:

The memory lost when the operating power is removed

Which of the following regions in a multi-stage turbine where efficiency a highest?

Calculate the use factor of a 135 MW plant with a load factor of 0.8 and a peak load of 120 MW if its operation is limited to 8500 hrs in a year.

Calculate the net radiation heat flux exchange of two bodies with surface temperature of 25 deg. C. The radiation heat transfer coefficient is 7.0 W/m²-k.

Calculate the reserve factor for a power plant with a load factor of 0.7 average load of 50 MW and rated capacity of 80 MW.

Maximum demand of 30 MW and 10 MW are connected to a power plant with a peak load of 70 MW. What is the diversity factor of the plant?

A gas in piston-cylinder set-up undergoes an expansion of such rate that PV1.2 =constant. Before the expansion process the pressure of the gas is 300 kPa and the volume is 0.50 m³. If the final volume of the gas is 0.1 m³, calculate the work done by the gas.

The phenomenon in which air enters a submerged suction pipe from the water surface is called a:

Where groundwater (wells and springs) or surface water (streams and takes) are used for feedwater, water hardness of _____ and alkalinity of pH 10 to be ph should be considered.

Which of the following is not a solid fuel?

Canisters of helmets shall be removed immediately after having been used on sucking water from a public service main or private-use water system

A small fitting with a double offset, or shaped like the letter U with the ends turned out.

The condition in which droplets of water are carried by steam in the boiler.

At the start of the compression process of an air-standard diesel power cycle the pressure is 100kpa and the temp is 15 deg. C. for a mean effective pressure of 1362 kPa and compression ratio of 18 the heat of combustion developed is 1800 kJ/kg. what is the thermal efficiency of the cycle?

Exergy is always _____.

A 5m thick flat plane (k = 60 w/m-k) is well insulated on its sides, while the top and bottom surfaces are maintained at 150 deg. Assuming a steady state heat conduction, calculate the temperature 4 m below the top surface.

A solid of diameter D=0.5 m and surface emissivity of 0.8 contains electrons that dissipate 100 W of heat. If it does not receive radiation from the surroundings, what is the surface temp?

Which of the following is basically a jet engine that exhausts into a turbine generator?

It is referred to as the maximum continuous power available from a hydroelectric power plant even under the most adverse hydraulic condition.

Energy destruction is a result of _____.

Working fluids used in refrigeration cycle decreases in temperature as they pass through the throttle valve. The Joule Thompson coefficient of these fluids is _____.

The interaction that occurs between a system and its surroundings as the system executes a process, which is the result of the system being at the temperature different from the surrounding, is _____.

Working fluids used in refrigeration cycle decreases in temperature as the pass through the throttle valve. The Joule Thompson Coefficient of these fluids is _____.

The interactions that occurs between a system and its surroundings as a system executes a process, which is the result of the system being at temperature different from the surrounding is _____.

An air pollutant which is the result of burning fuels oils.

Analysis of solid fuel to determine moisture, volatile matter, fixed carbon, and ash expressed as percentage of the total weight of the sample.

A gas analysis apparatus in which the percentage of oxygen, carbon dioxide and neonoxide in the gas measured by absorption in separate chemical solutions.

The water added to boiler feed to compensate for the water lost through blowdown, leakage, etc.

Gas flow caused by boiler’s pressure being less than boiler’s furnace pressure.

An automatic pressure-relieving device that opens in proportion to the increase in pressure over its opening pressure.

A rotating device used to convert kinetic energy into mechanical energy.

Air can be prevented from getting into the system by:

An excessively high head pressure could be caused by _____.

The solenoid valve is controlled by _____.

If the discharge side of the thermal expansion valve is warmer than the _____.

If the pressure is too high, _____.

If a pressurized water reactor (PWR), _____.

Which of the following property of coal has major influence on the design and operation of a steam power plant?

A boiler horsepower is equal to the evaporation of 3405lbs of 100 degrees C water per hr. how much steam in lb per hour a 700 horsepower boiler can generate?

_____ is obtained by mixing and burning precisely the right amount of fuel and oxygen so that products are left once combustion is complete.

What type of boiler commonly used in industrial and heavy commercial application due to less expensive to make low pressure, easier to maintain and repair?

During the emergency operation of the boiler, when there is no water in the gauge glass and steam comes out of the bottom trycock, the water level cannot be determined. What preventive measure the operator does to save the boiler?

The most important valve in the boiler operation and the last line of defense against disaster is known as _____.

A common test and very important when a boiler is being repaired and or replaced before being back in operation or in service is known as _____.

In heat transfer by conduction, due to symmetry the heat flow as a point is perpendicular to the isothermal surface through the point. This mode of conduction is a characteristic of _____.

Why should you avoid bending or twisting of fan blades in an air conditioning unit?

The heat transferred radially across insulated pipe per unit area

Under normal operating conditions, when a solid material to be dried is placed inside a batch tray dryer, the material is usually subjected _____.

A change of phase directly from vapor to solid without passing through the liquid state is called as _____.

In terms of heat transfer, the use of a cooling tower is said to be more efficient and more economical compared to an ordinary heat exchanger since _____.

It is a form of oxygen photochemicallly produced in nature.

What is the chemical formula of ozone

In the upper atmosphere, ozone is made by ultraviolet light reacting with _____.

The ozone concentration of parts per million (ppm) is generally considered maximum permissible for how many hours of exposure?

How may moisture be removed from air?

In cooling cycle, the dry bulb temp (db) of the air is lowered, what will happens to the relative humidity?

What is the effect of superheating the refrigerant?

A turbine setting where one disadvantage is the difficulty of lubricating the operating mechanism, with consequent relatively rapid water.

A patented device combining expansion and compression function in a single rotor permitting higher cycle temperatures.

A rough measure of the physical size of the equipment which must handle the specified quantity of the fluid.

The ratio of the highest main compressor discharge pressure as the lower main compressor inlet pressure.

The ratio of the actual partial pressure exerted by tge water vapor in any volume of air to the partial pressure that would be exerted by the water vapor in the air is saturated at the temperature of the air.

In sensible heating the absolute humidity remains constant but the relative humidity _____.

The relative humidity becomes 100% and where the water vapor start to condense.

Why should you avoid bending or twisting of fan blades in an air conditioning unit?

A type of refrigerant that will not damage the ozone layer.

Which of the following is the type of refrigerant that damages Ozone layer?

Large-bulb alcohol thermometer used to measure air speed or atmospheric condition by means of cooling.

The phenomenon that warm air rise and cold air settle is called _____.

Which of the following components of the window air conditioning system cleaned annually?

A cooled heat exchanger that transfer heat from compressed air to cooler air.

All the control stand, pitch of the turbine blades must be adjusted manually by a _____.

Runner blades are adjusted automatically in synchronism with turbine wicker gates by a/an _____.

What is supplied to the servomotor from the turbine governor oil system through the generator shaft and through a control valve?

Used to exhaust air from the casing for starting.

Advantage for propeller turbines of all types.

An office air conditioning system drew in a quantity of hot air from outside, cooled it to 1 deg. C, and mixed it with the internal air of a building. Care was taken to supply enough fresh air to eliminate objectionable odors. The temperature of the space was maintained constant, and yet some people became uncomfortable in the afternoon, why?

Equipment designed to reduce the amount of water vapor in the ambient atmosphere.

A large paper plant uses its own cogeneration power plant to generate its electricity because _____.

The volumetric output of a centrifugal pump is reduced by closing a valve part way on the intake side of the pump, throttling the intake. The reduction of flow is accompanied by “popping” noises which seem to come from inside the case.

If a man touches two metals which were kept together at room temperature, why would one metal feel colder that the other?

The ratio of the internal thermal resistance of a solid to the boundary layer thermal resistance is described by:

An instrument which is commonly used to measure the most important characteristics of fuel oil which is viscosity is known as:

In a refrigerator, this is a chamber for storing low-side liquid refrigerant in a system, which also serves as a surge drum.

The measure of a fluids resistance to flow (the internal friction of a fluid) as temperature increase.

A mechanical device used to burn solid fuel specifically used in coal power plant.

The chemically correct ratio of air fuel a mixture capable of perfect combustion with no unused air or fuel.

When a solid material is said to be “dry” it means that _____.

A hot block is cooled by blowing cool air over its top surface. The heat that is first transferred to the air layer close to the block is by conduction. It is eventually carried away from the surface by:

When drying banana chips under the sun, the rate of drying is faster _____.

Reflector of a nuclear reactor are made up of _____.

The function of a moderator in a nuclear reactor is _____.

Which of the following is the most commonly used moderator?

Ammonia leaks in the condenser can be detected by _____.