FUNDAMENTALS OF THERMODYNAMICS
10th Edition
ISBN: 9781119803645
Author: Sonntag
Publisher: WILEY
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 5, Problem 5.68P
Consider a room at 20°C that is cooled by an air conditioner with a COP of 3.2 using a power input of 2kW, and the outside temperature is 35°C. What is the constant in the heat transfer Eq. 5.15 for the heat transfer from the outside into the room?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
An inventor draws 25000 kJ/h of heat from a heat well at -30°C, which requires 1.2 kW of power. He claims to have developed a refrigeration cycle that dumps heat into the heat source at 20°C. environment There is no other energy transfer with Evaluate this claim.
Need help solving this problem. Please provide clear and concise steps in neat handwriting.
A bio-reactor is kept at 42°C by a heat pump driven by a motor of 2 kW. The reactor loses energy at a rate of 0.5 kW per degree difference to the colder ambient. The heat pump has a COP that is 50% that of a Carnot heat pump. What is the minimum ambient temperature for which the heat pump is sufficient?
Chapter 5 Solutions
FUNDAMENTALS OF THERMODYNAMICS
Ch. 5 - Prob. 5.1PCh. 5 - A windowmounted air conditioner removes 3.5kJ from...Ch. 5 - R410A enters the evaporator (the cold beat...Ch. 5 - A large heat pump should upgrade 4MW of heat at...Ch. 5 - A car engine 5g/s fuel (equivalent to addition of...Ch. 5 - Prob. 5.37PCh. 5 - R134a fills a 0.1m3 capsule at 20°C, 200kPa. It is...Ch. 5 - Air in a piston/ cylinder goes through a Carnot...Ch. 5 - A heat engine receives 7kW from a 300°C source and...Ch. 5 - Consider the previous problem and assume the...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- A large heat pump should upgrade 4 MW of heat at 65 C to be delivered as heat at 145 C. What is the minimum amount of work input that will drive this?arrow_forwardThe thermal efficiency of a Carnot heat engine is 30%. If the engine is reversed in operation to work as a heat pump with same operating conditions then what will be the COP for heat pump? (B) 2.33 (D) Can't be calculate (A) 0.30 (C) 3.33arrow_forwardA solar energy based heat engine which receives 80 kJ of heat at 100 deg C and rejects 70 kJ of heat to the ambient at 30 deg C is to be designed. The thermal efficiency of the heat engine isarrow_forward
- . Consider three reservoirs that are TH = 473.2 K, TL = 293.2 K and TI = 277.2 K. A Carnot heat engine can be reversed and used as either a heat pump or a refrigerator. In the case of a heat pump the heat flow to the higher temperature reservoir is the desired output and it is used to heat a room or building. In the case of the refrigerator the desired energy flow is the heat in from a region to be cooled. For the heat pump or refrigerator, the work input is provided by electricity. For this information answer the following questions: a) Calculate the Carnot Efficiency of a heat engine that operates between TH and TL. b) A room is maintained at a constant temperature of 20 C and has a heat loss of 20,000 W. Consider this room for a period of 3 hours. The surroundings are at a temperature of TI. In one option the room is heated using resistive heaters that are operated with electricity. b1)Determine the electrical energy input to these heaters. b2)Determine the efficiency of…arrow_forwardA solar collector absorbed 40W/m2 heat from the atmosphere. This is equal to the convection brought by air for drying purpose. If the temperature of the air is 40C while the solar collector area's temperature is 80C and neglecting effect of radiation, find the convective heat transfer coefficient.arrow_forward3.Two Carnot heat engines run in series with the efficiency of first engine is 1/k times the second. If the thermal reservoir at low and high temperatures were denoted by TL and TH, find the simplified ratio of heat absorbed to heat rejected by the second heat engine in terms of TL, TH and k only.arrow_forward
- An inventor comes to you saying he has invented a refrigerator that maintains a room at 20F while operating in a location at 80F with a coefficient of performance of 8.5, is this possible?arrow_forwardAnswer question 1 and 3arrow_forwardA water cooler for drinking water should cool 25 L/h water from 18 C to 10 C while the water reservoirs also gains 60 W from heat transfer. Assume that a small refrigeration unit with a COP of 2.5 does the cooling. Find the power input to the unit.arrow_forward
- 2. Between 300K and 600K is the operating temperature of a pair of heat pumps connected in series. The efficiency of the second heat pump is three times that of the first. Find the input work for the first and second heat pumps if the second heat pump absorbs 20kW of heat and the heat release in the first heat pump is the same.arrow_forwardHow to solve this thermodynamics question about mean power?arrow_forwardAsaparrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning
Refrigeration and Air Conditioning Technology (Mi...
Mechanical Engineering
ISBN:9781305578296
Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:Cengage Learning
The Refrigeration Cycle Explained - The Four Major Components; Author: HVAC Know It All;https://www.youtube.com/watch?v=zfciSvOZDUY;License: Standard YouTube License, CC-BY