A "cold room" used for low-temperature research is maintained at a constant temperature of 7.00°C. The refrigeration unit vents to outdoor air which is at 27.0°C. The rate at which energy is exhausted to the outdoors is 18.0 kW. The coefficient of performance (COP) of the refrigeration unit is equal to 40.0% of the COP of an ideal Carnot refrigerator. (a) At what rate (in kW) does the refrigeration unit remove energy from the room? (Round your answer to at least two decimal places.) kW (b) What is the power input (in kW) required by the refrigeration unit? kW (c) What is the entropy change of the Universe (in J/K) produced by the refrigeration unit after it operates for 3.00 h? J/K (d) If the outside temperature increases to 33.0°C, what is the percent change in the COP of the refrigeration unit? (Include the sign of the value in your answer.) %

A "cold room" used for low-temperature research is maintained at a constant temperature of 7.00°C. The refrigeration unit vents to outdoor air which is at 27.0°C. The rate at which energy is exhausted to the outdoors is 18.0 kW. The coefficient of performance (COP) of the refrigeration unit is equal to 40.0% of the COP of an ideal Carnot refrigerator. (a) At what rate (in kW) does the refrigeration unit remove energy from the room? (Round your answer to at least two decimal places.) kW (b) What is the power input (in kW) required by the refrigeration unit? kW (c) What is the entropy change of the Universe (in J/K) produced by the refrigeration unit after it operates for 3.00 h? J/K (d) If the outside temperature increases to 33.0°C, what is the percent change in the COP of the refrigeration unit? (Include the sign of the value in your answer.) %

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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Question

### Low-Temperature Research Refrigeration Unit Problem Set

A "cold room" used for low-temperature research is maintained at a constant temperature of 7.00°C. The refrigeration unit vents to outdoor air which is at 27.0°C. The rate at which energy is exhausted to the outdoors is 18.0 kW. The coefficient of performance (COP) of the refrigeration unit is equal to 40.0% of the COP of an ideal Carnot refrigerator.

#### Questions:

1. **Energy Removal Rate**
- **(a)** At what rate (in kW) does the refrigeration unit remove energy from the room?
(Round your answer to at least two decimal places.)

Input field: ____________ kW

2. **Power Input Requirement**
- **(b)** What is the power input (in kW) required by the refrigeration unit?

Input field: ____________ kW

3. **Entropy Change**
- **(c)** What is the entropy change of the Universe (in J/K) produced by the refrigeration unit after it operates for 3.00 h?

Input field: ____________ J/K

4. **Coefficient of Performance Change**
- **(d)** If the outside temperature increases to 33.0°C, what is the percent change in the COP of the refrigeration unit? (Include the sign of the value in your answer.)

Input field: ____________ %

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This problem set involves calculating various parameters required to understand the efficiency and performance of a refrigeration unit used in a controlled low-temperature environment. The focus is on energy removal rate, power input, entropy change, and the influence of external temperature changes on the coefficient of performance.

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