THERMO CO1/CO2

What is the primary significance of knowing the calorific value of fuels recommended by engine manufacturers for maximizing fuel efficiency aboard ships?

• To adjust fuel-air ratios for complete combustion

• To regulate exhaust gas recirculation rates

   

• To optimize engine operating temperatures

• To determine the fuel's energy content for efficient utilization.

How does the calorific value of fuel affect the performance of diesel engines aboard ships?

• Higher calorific value fuels result in lower exhaust emissions

• Higher calorific value fuels produce more power per unit mass.

• Lower calorific value fuels require higher injection pressures

   

• Lower calorific value fuels lead to increased engine wear

Which combustion equation represents the complete combustion of methane (CH₄) in a gas turbine aboard a ship, producing carbon dioxide (CO₂) and water (H₂O)? 

• CH₄ + 2O₂ → CO₂ + 2H₂O

• CH₄ + 3O₂ → CO₂ + 2H₂Ov

• CH₄ + O₂ → CO₂ + H₂O

• CH₄ + 4O₂ → CO₂ + 2H₂O

How does the expansion process contribute to the efficiency of refrigeration systems aboard ships?

• Expansion increases the temperature of the refrigerant vapor

• Expansion minimizes energy losses during heat transfer

• Expansion reduces the pressure of the refrigerant vapor

• Expansion promotes the evaporation of the refrigerant liquid

What role does the calorific value of fuel play in determining the efficiency of heat transfer processes aboard ships? 

• Lower calorific value fuels influence the rate of steam generation.

• Higher calorific value fuels decrease thermal efficiency

   

• Higher calorific value fuels result in higher exhaust gas temperatures

• Lower calorific value fuels reduce the effectiveness of heat exchangers

How does the stoichiometric air-fuel ratio compare between complete and incomplete combustion processes aboard ships? 

• The stoichiometric ratio is the same for both complete and incomplete combustion.

• The stoichiometric ratio is lower for complete combustion and higher for incomplete combustion.

• The stoichiometric ratio varies depending on the type of fuel used.

• The stoichiometric ratio is higher for complete combustion and lower for incomplete combustion

What is the primary purpose of a refrigeration system aboard ships?

• To maintain low temperatures for food preservation and cargo storage.

   

• To control humidity levels in engine rooms

• To provide heating to living quarters and workspaces

• To generate electricity for onboard equipment

How does incomplete combustion affect engine performance in steam propulsion systems aboard ships?

• Increases engine performance due to faster reaction rates

• Increases engine performance due to reduced fuel consumption

   

• Decreases engine performance due to fouling of turbine blades.

• Decreases engine performance due to reduced steam pressure

How does incomplete combustion affect exhaust emissions in gas turbines aboard ships?

• Increases in exhaust emissions due to higher fuel consumption

• Increases in exhaust emissions due to the presence of carbon monoxide and unburned hydrocarbons.

   

• Decreases in exhaust emissions due to reduced nitrogen oxide formation

• Decreases in exhaust emissions due to lower combustion temperature

Which fundamental principle of refrigeration systems describes the process of removing heat from a space or substance to lower its temperature? 

• Expansion

   

• Condensation

• Evaporation

• Compression