The cabinet of a refrigerator is 40 cm wide, 110 cm high and 50 cm deep....
Fantastic news! We've Found the answer you've been seeking!
Question:
Transcribed Image Text:
The cabinet of a refrigerator is 40 cm wide, 110 cm high and 50 cm deep. The side walls, door and top consist of an inner layer of plastic (kp = 0.25 W/m-K), a middle layer of grass wool (kg=0.035 W/m-K), and an outer layer of steel (ks = 12.1 W/m K), of thicknesses 2 mm, 60 mm and 1.5 mm respectively. When the refrigerator is operating steadily and the temperature of the surroundings is 25 °C, the temperature of the contents, which may be assumed to be uniform, is 5 °C. The convection heat transfer coefficients on the internal and the external surfaces are 4.0 W/m²K and 6.0 W/m²K respectively. Heat transfer through the base is negligible. Neglect the difference in area between the internal and external surfaces of the cabinet. 1. Estimate the heat transfer rate into the cabinet assuming radiation heat transfer is negligible. 2. Verify if it is reasonable to neglect radiation heat transfer in part 1, assume the emissivity of the wall is between 0.5 and 0.9. 3. Use the natural convection correlation to verify if it is a good estimation to use a convection coefficient of 6 W/m²-K on the external side wall. The cabinet of a refrigerator is 40 cm wide, 110 cm high and 50 cm deep. The side walls, door and top consist of an inner layer of plastic (kp = 0.25 W/m-K), a middle layer of grass wool (kg=0.035 W/m-K), and an outer layer of steel (ks = 12.1 W/m K), of thicknesses 2 mm, 60 mm and 1.5 mm respectively. When the refrigerator is operating steadily and the temperature of the surroundings is 25 °C, the temperature of the contents, which may be assumed to be uniform, is 5 °C. The convection heat transfer coefficients on the internal and the external surfaces are 4.0 W/m²K and 6.0 W/m²K respectively. Heat transfer through the base is negligible. Neglect the difference in area between the internal and external surfaces of the cabinet. 1. Estimate the heat transfer rate into the cabinet assuming radiation heat transfer is negligible. 2. Verify if it is reasonable to neglect radiation heat transfer in part 1, assume the emissivity of the wall is between 0.5 and 0.9. 3. Use the natural convection correlation to verify if it is a good estimation to use a convection coefficient of 6 W/m²-K on the external side wall.
Expert Answer:
Answer rating: 100% (QA)
SOLUTION 1 Estimate the heat transfer rate into the cabinet assuming radiation heat transfer is negligible Since radiation heat transfer is negligible we can assume that the temperature of the surroun... View the full answer
Related Book For
Posted Date:
Students also viewed these accounting questions
-
Lisa is seeking to enter the U.S. under the Visa Waiver Program to visit the Empire State Building. Lisa has always dreamed about visiting the U.S. as her country was so poverty stricken and also...
-
The roof of a house consists of a 15-cm-thick concrete slab (k = 2 W/m·K) that is 15 m wide and 20 m long. The convection heat transfer coefficients on the inner and outer surfaces of the roof...
-
A computer IC chip consumes 10 W of power, which is dissipated as heat. The chip measures 4 cm by 4 cm on a side and is 0.5-cm thick. Currently, the IC chip is packaged into an electronic device as...
-
Explain why the coffee shop manager should measure elasticity using the mid-point method in his calculations.
-
Munoz Corporation uses activity based costing to determine product costs for external financial reports. At the beginning of the year, management made the following estimates of cost and activity in...
-
What level of service does this reorder point correspond to? What would the reorder point and safety stock need to be to achieve the desired service level? Discuss how Jessica James might...
-
Use the information from question 5. After delivery, at what amount is the merchandise carried on the U.S. companys books? Use the following forward and spot prices for Canadian dollars (C\($)\) to...
-
Fred Moss, owner of Moss Interiors, is negotiating for the purchase of Zweifel Galleries. The balance sheet of Zweifel is given in an abbreviated form below. Moss and Zweifel agree that: 1. Land is...
-
Required information [The following information applies to the questions displayed below.] On January 1, 2024, Red Flash Photography had the following balances: Cash, $31,000; Supplies, $9,900; Land,...
-
A Critical Care ICU unit with the following labor standards in HPPD and a budgeted average daily census of 20/day will need a minimum of how many FTEs in their total paid FTEs? Required data is...
-
Scientists want to estimate the mean weight of mice after they have been fed a special diet. From previous studies, it is known that the weight is normally distributed with standard deviation of 3...
-
A company purchases equipment at the beginning of the year at a cost of $45,900. The equipment's useful life is estimated at 10 years, or 389,000 units of product, with a $7,000 salvage value. During...
-
A U.S. publicly traded company's fiscal year ends on May 31. If the company's public float is $400 million dollars and annual revenues are $350 million dollars, what is the latest date that Form 10-K...
-
What role do organisms play in biogeochemical cycles, and how do these interactions at the organismal level contribute to ecosystem function and global environmental processes ?
-
Sale of Equipment was acquired at the beginning of the year at a cost of $ 4 0 , 2 5 0 . The equipment was depreciated using the double - declining - balance method based on an estimated useful life...
-
HGR Biscuit Company started its operations in Ambala City, Haryana; in 2001. The company was growing at an annual rate of 20 %, which was above the industry average. However, for the last three...
-
3. [9 Pt.] Company has a total of 12 salespeople it wants to assign to three regionsthe South, the East, and the Midwest. A salesperson in the South earns $600 in profit per month for the company, a...
-
One study found that the elderly who do not have children dissave at about the same rate as the elderly who do have children. What might this finding imply about the reason the elderly do not dissave...
-
The deflection of an alpha particle as it passes through a magnetic field is much less than the deflection of a beta particle ( Figure 11.3 ). Explain why. Alpha Gamma Beta
-
Use conservation of energy to show that the speed with which water flows out of a tap near the bottom of an open container equals 2gh where h is the height of the freestanding surface of the water...
-
A car is stopped at a red light. When the light turns green, the car begins to accelerate with a constant acceleration of 4.0 m/s 2 . Just as the car starts moving, it is passed by a small truck...
-
1.7 Limitations of Comparative Advantage. The key to understanding most theories is what they say and what they don't. Name four or five key limitations to the theory of comparative advantage.
-
1.6 Post-LIBOR Scandal. Why do you think the UK government has resolved against the total elimina- tion of LIBOR benchmarks after the scandal?
-
1.9 Aidan's Globalization. After reading the chapter's description of Aidan's globalization process, how would you explain the distinctions between interna- tional, multinational, and global...
Study smarter with the SolutionInn App