Introduction to Refrigeration

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Questions and Answers

What does refrigeration aim to achieve in terms of temperature?

  • Increase humidity levels in the space
  • Maintain a temperature higher than the surrounding atmosphere
  • Decrease air motion within the space
  • Extract heat from the space to maintain a lower temperature (correct)

Why is control of the environment essential for living and non-living subjects?

  • To decrease energy consumption
  • To increase air pressure within the space
  • To adapt to unpredictable variations in the physical environment (correct)
  • To create extreme conditions

Which variables are mentioned as important in the physical environment?

  • Wind speed, altitude, temperature, and humidity
  • Temperature, humidity, pressure, and light
  • Altitude, wind speed, pressure, and light intensity
  • Temperature, humidity, pressure, and air motion (correct)

What is the main focus of refrigeration and air-conditioning?

<p>To provide comfort by controlling environments (A)</p> Signup and view all the answers

Why is adaptation to unpredictable variations challenging for living beings?

<p>Efficiency becomes unfeasible (D)</p> Signup and view all the answers

What is the literal meaning of refrigeration?

<p>Production of cold confinement relative to surroundings (A)</p> Signup and view all the answers

What is the precise meaning of refrigeration?

<p>Cooling down a space (A)</p> Signup and view all the answers

Why do food products spoil less at lower temperatures?

<p>Due to increased molecular motion at lower temperatures (C)</p> Signup and view all the answers

In the context of refrigeration, why is the volume of the space under consideration mentioned?

<p>To explain why the temperature changes more in that space (C)</p> Signup and view all the answers

Why is it uncomfortable to travel in a car during an Indian summer?

<p>Because outside temperatures are very high (D)</p> Signup and view all the answers

How does a refrigerator preserve perishable food products?

<p>By throwing away unwanted heat from the food products (C)</p> Signup and view all the answers

What role does a heat pump play in air-conditioned cars during winter?

<p>It pumps heat into the car (A)</p> Signup and view all the answers

Why does heat need to be supplied inside a car during winter driving in Delhi or Kanpur?

<p>To increase the temperature inside the car (B)</p> Signup and view all the answers

What is one of the primary reasons for using refrigerators in homes, canteens, and hotels?

<p>To preserve perishable food products for a longer duration (C)</p> Signup and view all the answers

Why is it necessary to keep food products at a lower temperature in refrigerators?

<p>To prevent spoilage by reducing bacterial growth (C)</p> Signup and view all the answers

How does refrigeration control the temperature of a space?

<p>By reversing the operation and removing heat from a lower temperature space (A)</p> Signup and view all the answers

What is the precise meaning of air conditioning?

<p>Controlling temperature and humidity (C)</p> Signup and view all the answers

Which parameter is considered most important in air conditioning?

<p>Temperature (B)</p> Signup and view all the answers

What is required for comfort according to the text?

<p>Clean air and air motion (A)</p> Signup and view all the answers

In which type of air conditioning is extra moisture typically removed from the space?

<p>Summer air conditioning (A)</p> Signup and view all the answers

What is added to spaces in winter air conditioning in cold places?

<p>Humidity (A)</p> Signup and view all the answers

What does industrial air conditioning include?

<p>Air conditioning of photographic products (D)</p> Signup and view all the answers

What role does air motion play in air conditioning according to the text?

<p>It helps in temperature control (A)</p> Signup and view all the answers

What additional parameter falls under the purview of air conditioning in some applications?

<p>Control of air pressure (D)</p> Signup and view all the answers

What aspect does refrigeration primarily focus on in air conditioning?

<p>Temperature control (A)</p> Signup and view all the answers

What kind of adjustments are made in industrial air conditioning compared to comfort air conditioning?

<p>Different control parameters influenced (A)</p> Signup and view all the answers

How can a refrigeration system be used as a heat pump?

<p>By changing the direction of flow of the refrigerant (D)</p> Signup and view all the answers

In which century did East Indians start producing ice by dissolving salt in water?

<p>4th century A.D. (C)</p> Signup and view all the answers

Who obtained the first British Patent related to refrigeration?

<p>Thomas Hariss (B)</p> Signup and view all the answers

What was the main working fluid used in Jacob Perkins' hand-operated refrigeration system?

<p>Ether (B)</p> Signup and view all the answers

Who developed the world's first installation of a refrigeration machine for brewery in 1860?

<p>Dr. James Harrison (C)</p> Signup and view all the answers

What did Dr. John Gorrie obtain a patent for in 1851?

<p>Cold air machine for curing high fever (C)</p> Signup and view all the answers

In what century did people start developing methods to produce ice artificially?

<p>19th century (B)</p> Signup and view all the answers

Which refrigeration system used ammonia and water in a vapor-absorption system developed by Ferdinand Carre?

<p>Absorption system (C)</p> Signup and view all the answers

What distinguishes heating operation from cooling operation according to some people?

<p>Heating operation is not associated with refrigeration at all, cooling is. (B)</p> Signup and view all the answers

Why is superheating of the suction vapour advisable in refrigeration and air-conditioning systems?

<p>To ensure complete vaporization of the liquid in the evaporator (D)</p> Signup and view all the answers

What serves as a means of actuating and modulating the capacity of the expansion valve in refrigeration systems?

<p>Suction Vapour Superheat (B)</p> Signup and view all the answers

For which refrigerant is the maximum Coefficient of Performance (COP) obtained with superheating of the suction vapour?

<p>Freon 12 (D)</p> Signup and view all the answers

What is the effect of superheating on the specific volume of suction vapour?

<p>Increase in specific volume (A)</p> Signup and view all the answers

How does an increase in condenser pressure affect the refrigerating capacity and power consumption per ton of refrigeration?

<p>Has no effect (D)</p> Signup and view all the answers

What is the heat absorbed by the refrigerant during evaporation called?

<p>Refrigerating effect (C)</p> Signup and view all the answers

What is the formula for Coefficient of Performance (C.O.P.) for a refrigerating system?

<p>(Refrigerating effect) / (Work done) (A)</p> Signup and view all the answers

What happens to the Coefficient of Performance (C.O.P.) when the suction pressure decreases?

<p>Decreases (D)</p> Signup and view all the answers

What effect does an increase in discharge pressure have on compressor work and refrigeration effect?

<p>Increases compressor work, decreases refrigeration effect (C)</p> Signup and view all the answers

What happens to the refrigerating capacity when the evaporator pressure decreases?

<p>Decreases (C)</p> Signup and view all the answers

How does a decrease in evaporator temperature affect the specific volume of suction vapour?

<p>Increase (A)</p> Signup and view all the answers

What is the impact of increasing the condenser pressure on refrigerating capacity and power consumption?

<p>Decreases refrigerating capacity, increases power consumption (B)</p> Signup and view all the answers

What is the relationship between pressure ratio and volumetric efficiency?

<p>Pressure ratio increases with volumetric efficiency (C)</p> Signup and view all the answers

What factor influences power consumption due to increased mass flow in a refrigeration system?

<p>Decreased refrigerating capacity (D)</p> Signup and view all the answers

How does a decrease in evaporator temperature impact the pressure ratio within a system?

<p>Increases the pressure ratio (A)</p> Signup and view all the answers

What was the significant development in refrigeration systems after the 1920s?

<p>Invention of chlorfluor hydrocarbons (A)</p> Signup and view all the answers

Which industry saw stagnation in using NH3 and SO2 as refrigerants around 1930?

<p>Refrigeration industry (A)</p> Signup and view all the answers

What does industrial air conditioning aim to provide for workers?

<p>Comfort in hostile environments (A)</p> Signup and view all the answers

What is the primary focus of comfort air conditioning in buildings?

<p>Creating comfortable conditions for occupants (A)</p> Signup and view all the answers

Why did the refrigeration industry see extensive diversification after the 1920s?

<p>Due to the development of new chlorfluor hydrocarbons (B)</p> Signup and view all the answers

What was an important advantage of chlorfluor carbons over NH3 and SO2 as refrigerants?

<p>Non-toxic properties (C)</p> Signup and view all the answers

In which industry did the invention of new refrigerants take place around 1930?

<p>GE Corporation of USA (A)</p> Signup and view all the answers

What is the primary reason for the development of commercial units utilizing waste heat or solar energy?

<p>&quot;Predicted energy crisis in the future&quot; (C)</p> Signup and view all the answers

What is the main purpose of the evaporator in a vapour compression refrigeration system?

<p>To evaporate the liquid-vapour refrigerant at low pressure and temperature (C)</p> Signup and view all the answers

What is the purpose of the receiver in a vapour compression refrigeration system?

<p>To store the condensed liquid refrigerant (A)</p> Signup and view all the answers

During which process in the cycle is the liquid refrigerant expanded by throttling through the expansion valve?

<p>Expansion process (A)</p> Signup and view all the answers

What happens to the high-pressure and high-temperature vapor refrigerant in the condenser of a refrigeration system?

<p>It is cooled and condensed (C)</p> Signup and view all the answers

What is the function of the expansion valve in a vapour compression refrigeration system?

<p>To allow the liquid refrigerant to pass at a controlled rate (D)</p> Signup and view all the answers

What is the purpose of the condenser in a vapour compression refrigeration system?

<p>To cool and condense the refrigerant (C)</p> Signup and view all the answers

Which part of a vapour compression refrigeration system is responsible for compressing the low pressure and low temperature vapor refrigerant?

<p>Compressor (B)</p> Signup and view all the answers

What does the evaporator of a vapour compression system do with regard to heat?

<p>Absorbs latent heat of vaporization from its surroundings. (A)</p> Signup and view all the answers

Which process in the vapour compression cycle involves changing high-pressure vapor into liquid form?

<p>Condensing Process (A)</p> Signup and view all the answers

What is happening to the refrigerant during throttling through an expansion valve?

<p>Changing phase without heat exchange. (D)</p> Signup and view all the answers

Why is air conditioning important in computer rooms?

<p>To prevent electronic components from overheating (A)</p> Signup and view all the answers

What can happen if humidity is not properly controlled in printing processes?

<p>Static electricity problems (C)</p> Signup and view all the answers

Why are refrigeration and air conditioning crucial for the photographic products industry?

<p>To prevent humidity-related damage to raw materials (C)</p> Signup and view all the answers

In the context of precision metal parts manufacturing, why is air filtration important?

<p>To minimize dust and maintain cleanliness (A)</p> Signup and view all the answers

What is the main purpose of a vapour compression cycle in refrigeration systems?

<p>To circulate and alternate condensing/evaporating refrigerants (D)</p> Signup and view all the answers

How does proper air conditioning benefit textile plants?

<p>By maintaining yarn flexibility and strength (C)</p> Signup and view all the answers

What role does refrigeration play in food storage and distribution?

<p>Extending the storage life of perishable items (D)</p> Signup and view all the answers

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