Energy Sources and Thermodynamics

Questions and Answers

What is the term used for an opening where hot energy from the earth is harnessed?

Volcano opening

Hot water source

Geothermal source (correct)

Fumamle

What is commonly referred to as the speed of sound?

Sound velocity (correct)

Acoustic velocity (correct)

Critical velocity

Subsonic velocity

What would you call a boiler that is marked indicating its rejection?

Unfired boiler

Condemned boiler (correct)

Second hand boiler

Reinstalled boiler

What is the term for the velocity at which a small pressure wave moves through a fluid?

Sonic velocity Signup and view all the answers

What is a characteristic feature of mechanical steam traps?

They pass condensate at steam temperature Signup and view all the answers

What do you call the mixture used in laboratory methods of producing a drop in temperature, commonly known as the mixture of ice and salt?

Frigorific mixture Signup and view all the answers

Which scale of temperature uses the melting point of ice as 0 degrees and the boiling point of water as 80 degrees?

Reaumur Scale Signup and view all the answers

What is the amount of heat energy required to raise the temperature of one pound of water one degree Fahrenheit?

British thermal unit Signup and view all the answers

What term refers to a factor used in calculating overall heat transfer through condenser tubes, including the heat transfer rate affected by accumulated dirt?

Fouling factor Signup and view all the answers

Which refrigeration system component is described as an evaporator arranged with a tank or drum located above the coil?

Flooded evaporator Signup and view all the answers

Which component in a cooling system serves specifically to condense refrigerants?

Water-cooled condenser Signup and view all the answers

What is the overall heat transfer factor that takes into account the thermal resistance of a layer of dirt?

Fouling factor Signup and view all the answers

Which of the following pairs correctly identifies a type of condenser and its description?

Water-cooled condenser - uses water to remove heat Signup and view all the answers

What is a characteristic feature of thermodynamic steam traps?

They pass condensate at steam temperature Signup and view all the answers

What is the purpose of strainers installed on steam lines being fitted on their sides?

To provide maximum screening area for the steam Signup and view all the answers

Which of the following statements about steam traps is incorrect?

They can only operate in high-pressure steam systems Signup and view all the answers

What is the result of using a heat exchanger rating to calculate steam consumption?

The true connected heat load may differ from the rated figure Signup and view all the answers

In a system employing open sprinklers, what activates the sprinklers?

The operation of a fire detection system Signup and view all the answers

Why is it important to manage condensate in a steam system?

To minimize heat loss and increase efficiency Signup and view all the answers

What type of system uses sprinklers connected to a water supply that is opened during a fire detection event?

Wet pipe system Signup and view all the answers

Which statement is true regarding condensate entering the boiler feed tank?

Condensate should be mixed with make-up water before entering Signup and view all the answers

Which type of boiler is defined by specific limits on diameter and pressure?

Power boiler Signup and view all the answers

How does a float trap vent air more effectively than an inverted bucket trap?

A float can quickly adjust to the presence of air Signup and view all the answers

Which characteristic is true for a float trap with an automatic air vent?

It stops the trap from freezing in cold weather Signup and view all the answers

What happens to entropy in a closed system when heat is applied?

Entropy is always increasing over time Signup and view all the answers

Which of the following statements is accurate regarding the characteristics of mechanical steam traps?

Mechanical steam traps are not affected by increasing back pressure Signup and view all the answers

What defines a power boiler in terms of its function?

It generates steam for external use through heat application Signup and view all the answers

What should be expected regarding the temperature of condensate in a well-functioning system?

Condensate temperature will increase with systemic heat Signup and view all the answers

Which factor may limit a boiler from being categorized as a power boiler?

Falling below the heating surface area requirement Signup and view all the answers

What is one method to reduce the temperature and pressure in a boiler?

Throttling the steam flow into uncontrolled nozzles Signup and view all the answers

What is a key advantage of operating a steam engine in a condensing mode?

It allows for increased mean effective pressure in the system Signup and view all the answers

How does superheated steam differ from saturated steam at the same pressure?

Superheated steam contains more heat energy Signup and view all the answers

Which of the following statements about superheated steam is untrue?

It can heat products evenly Signup and view all the answers

At 6 bar g, what characteristic does superheated steam exhibit?

It possesses a temperature greater than 165 °C Signup and view all the answers

What is the primary role of a sub-cooler in a two-stage refrigerant system?

To reduce total power and heat rejection to the second stage Signup and view all the answers

What type of check valves should be installed in a high-pressure boiler's water gauge?

Vertical swing-check valves Signup and view all the answers

What defines the efficiency of a riveted joint?

Strength of the riveted joint to the strength of the solid plate Signup and view all the answers

Which of the following describes the behavior of superheated steam?

It has a lower specific volume than saturated steam Signup and view all the answers

Study Notes

Energy Sources and Additives

An opening where hot energy from the earth is harnessed is known as a geothermal energy source.
Engine oil additives are used to prevent or reduce deposits and corrosion by neutralizing combustion byproducts.
Types of oil additives include corrosion inhibitors, oxidation inhibitors, detergents, and dispersants.

Speed of Sound

The speed of sound is referred to as sound velocity or acoustic velocity.
It is also known as sonic velocity, subsonic velocity, supersonic velocity, or hypersonic velocity based on the context.

Types of Boilers

Boilers can be categorized based on certain characteristics:
- Condemned boiler: marked as rejected.
- Unfired boiler: does not utilize fuel.
- Second-hand or reinstalled boiler: formerly used elsewhere.
A power boiler is used to generate steam through direct heat and must adhere to specific pressure and size limits.

Thermodynamic Concepts

Specific heat: amount of heat needed to raise one pound of water by one degree Fahrenheit.
The term "entropy" in the universe is related to the degree of disorder or randomness, which is always increasing over time.
Thermodynamic steam traps pass condensate at steam temperature and operate by holding back condensate until cooled.

Heat Transfer Factors

The factor used for calculating overall heat transfer through tube walls is known as the fouling factor, accounting for buildup on surfaces.
Mechanical steam traps with automatic air vents are superior for venting air due to their rapid adjustment to air presence.

Refrigeration Systems

A closed vessel generating steam for power generation is called a power boiler.
Refrigerant systems can include evaporators arranged with tanks to allow sufficient refrigerant flow.

Temperature Scales

The Reaumur Scale uses 0°C as the melting point of ice and 80°C as the boiling point of water.
Other temperature scales include the Carrene Scale, Genetrnn Scale, and Frigorie Scale.

Steam Properties

Superheated steam compared to saturated steam at the same pressure contains more heat energy, has greater enthalpy, and condenses at a higher temperature.
Superheated steam can exhibit severe erosion in pipes and cause uneven heating of products.

Mechanical and Structural Considerations

The efficiency of a riveted joint is defined as the ratio of the strength of the riveted joint to the strength of a solid plate.
Automatic shut-off valves for water gauges installed on high-pressure boilers must be designed appropriately, such as spring-loaded check valves.

General Concepts

Entropy in processes typically suggests a trend toward increased disorder or thermal energy dispersion over time.
Strainers installed on steam lines should be fitted on their sides to prevent water accumulation and enhance cleanliness.

Conclusively

The principles of thermodynamics, steam systems, heat transfer, and structural integrity are critical in engineering and mechanical contexts, influencing design and operational efficiency.

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Description

Explore the fundamental concepts of energy sources, including geothermal energy and various types of oil additives. Additionally, delve into the characteristics of boilers and the speed of sound, examining their definitions and classifications. This quiz covers an exciting range of topics in thermodynamics and energy systems.