If a refrigeration plant's evaporator temperature is decreased while the condenser temperature is held constant, the required compressor horsepower will________________?
Show answer Hide answer
Answer: B. more
Explanation
Lowering the evaporator temperature while holding condenser temperature constant increases compression ratio. Higher compression ratios require the compressor motor to perform more work per unit of mass. Increased work input directly translates to higher compressor horsepower requirements for the plant. Refrigeration system capacity drops when the evaporating temperature is decreased for a fixed load. Specific volume of suction vapor increases at lower pressures, reducing mass flow rate through cylinders. Power input rises because the refrigerant must be compressed across a larger pressure difference.
Operators must avoid lowering evaporator temperatures below necessary levels to save electrical energy. Cold storage facilities carefully balance setpoints to prevent unnecessary increases in compressor power usage. Understanding these trends helps engineers select appropriately sized motors for industrial refrigeration compressors. Same horsepower would violate thermodynamic principles governing compression work requirements across pressure drops. Less horsepower occurs when the pressure lift across the compressor is reduced, not increased. Compressor power requirements are entirely predictable using standard thermodynamic refrigeration cycle charts.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Which of the options presented represents an example of a group incentive plan?
Show answer Hide answer
Answer: A. Scanlon Plan
The Scanlon Plan is a well-known group incentive scheme that rewards workers based on labor cost savings and productivity improvements. This participatory management system distributes bonuses to all employees when organ...
Q2. In a vapor compression refrigeration loop, the ratio of heat absorbed in the evaporator to heat rejected in the condenser is_________________?
Show answer Hide answer
Answer: B. less
In a vapor compression refrigeration cycle, heat rejected in the condenser equals evaporator heat absorption plus compressor work input, making the ratio less than one. Energy conservation dictates that the condenser hea...
Q3. Within a flooded evaporator refrigeration system, an accumulator placed at the compressor suction line serves to___________________?
Show answer Hide answer
Answer: A. collect liquid refrigerant and prevent it from going to compressor
An accumulator in a flooded evaporator system traps unevaporated liquid refrigerant securely. This separation ensures that only dry vapor enters the compressor suction line during operation. Preventing liquid refrigerant...
Q4. In a standard vapor compression refrigeration cycle, the rate of refrigerant flow is regulated by___________________?
Show answer Hide answer
Answer: D. expansion valve
The expansion valve regulates the flow rate of liquid refrigerant entering the evaporator in a vapor compression cycle. By creating a controlled pressure drop, this device meters the exact mass flow required to match coo...
Q5. In a vapor compression cycle, the physical state of the refrigerant immediately exiting the condenser is________________?
Show answer Hide answer
Answer: D. before entering the expansion valve
Immediately exiting the condenser, the refrigerant is in a high-pressure liquid state before it reaches the expansion valve. Condensation completes inside the condenser coils, transforming hot vapor into subcooled high-p...
Q6. Within a vapor compression refrigeration system, the refrigerant exists in a liquid state between which two components_________________?
Show answer Hide answer
Answer: C. expansion valve and evaporator
In a vapor compression system, refrigerant exists as a high pressure liquid leaving the condenser. This high pressure liquid travels to the expansion valve where its pressure drops rapidly. Therefore, the liquid state is...