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Difficulty: MediumDrawing Logical Conclusions

Read the following passage:

Commercial walk-in freezers accumulate frost on evaporator coils during standard cooling cycles, reducing thermal transfer efficiency. To clear this frost without shutting down the entire refrigeration system, a hot-gas defrost valve redirects high-pressure vapor directly from the compressor discharge into the evaporator, bypassing the condenser and expansion valve. Because the refrigerant bypasses the condenser, it enters the evaporator while retaining its heat of compression. Once the evaporator temperature sensor registers that all ice has melted, the bypass valve closes and normal refrigerant routing through the condenser and expansion valve resumes.

Statement: If the hot-gas defrost bypass valve fails to close after the ice has melted, the refrigeration system will be prevented from resuming its normal cooling cycle.

Answer: Answer

Answer

True
The conclusion is logically valid because the passage explicitly states that normal refrigerant routing through the condenser and expansion valve resumes only when the bypass valve closes. Therefore, a valve that fails to close will continuously divert hot gas into the evaporator and prevent standard cooling.

Step-by-Step Solution

1
Identify the conditions required for the refrigeration system to perform standard cooling.
Standard cooling requires refrigerant to travel through the condenser and expansion valve rather than entering the evaporator with heat of compression.
Understanding the normal mechanical flow establishes the baseline required for cooling.
2
Analyze what happens when the hot-gas defrost cycle is active.
The open bypass valve sends hot compressor gas directly to the evaporator, bypassing the cooling components.
Determining the effect of the bypass route shows how the defrost state opposes the cooling state.
3
Deduce the logical outcome if the bypass valve fails to close after defrosting.
Because normal routing only resumes when the valve closes, a valve that stays open keeps routing heated vapor to the evaporator, preventing the resumption of normal cooling.
Synthesizing the mechanical dependency confirms that the statement is strictly supported by the text.

Key Concept

Synthesizing procedural conditions and causal dependencies to draw a valid technical deduction.
Estimated Time:1m 15s
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Drawing Logical Conclusions

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