Thermodynamics: An Engineering Approach
9th Edition
ISBN: 9781259822674
Author: Yunus A. Cengel Dr., Michael A. Boles
Publisher: McGraw-Hill Education
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Textbook Question
Chapter 6.11, Problem 164FEP
A heat pump is absorbing heat from the cold outdoors at 5°C and supplying heat to a house at 25°C at a rate of 18,000 kJ/h. If the power consumed by the heat pump is 1.9 kW, the coefficient of performance of the heat pump is
- (a) 1.3
- (b) 2.6
- (c) 3.0
- (d) 3.8
- (e) 13.9
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Chapter 6 Solutions
Thermodynamics: An Engineering Approach
Ch. 6.11 - A mechanic claims to have developed a car engine...Ch. 6.11 - Describe an imaginary process that violates both...Ch. 6.11 - Describe an imaginary process that satisfies the...Ch. 6.11 - Describe an imaginary process that satisfies the...Ch. 6.11 - An experimentalist claims to have raised the...Ch. 6.11 - Consider the process of baking potatoes in a...Ch. 6.11 - Prob. 7PCh. 6.11 - What are the characteristics of all heat engines?Ch. 6.11 - What is the KelvinPlanck expression of the second...Ch. 6.11 - Is it possible for a heat engine to operate...
Ch. 6.11 - Does a heat engine that has a thermal efficiency...Ch. 6.11 - In the absence of any friction and other...Ch. 6.11 - Are the efficiencies of all the work-producing...Ch. 6.11 - Baseboard heaters are basically electric...Ch. 6.11 - Consider a pan of water being heated (a) by...Ch. 6.11 - A heat engine has a total heat input of 1.3 kJ and...Ch. 6.11 - A steam power plant receives heat from a furnace...Ch. 6.11 - A heat engine has a heat input of 3 104 Btu/h and...Ch. 6.11 - A 600-MW steam power plant, which is cooled by a...Ch. 6.11 - A heat engine with a thermal efficiency of 45...Ch. 6.11 - A heat engine that propels a ship produces 500...Ch. 6.11 - A steam power plant with a power output of 150 MW...Ch. 6.11 - An automobile engine consumes fuel at a rate of 22...Ch. 6.11 - Solar energy stored in large bodies of water,...Ch. 6.11 - A coal-burning steam power plant produces a net...Ch. 6.11 - An Ocean Thermal Energy Conversion (OTEC) power...Ch. 6.11 - Prob. 27PCh. 6.11 - Prob. 29PCh. 6.11 - What is the difference between a refrigerator and...Ch. 6.11 - Prob. 31PCh. 6.11 - Define the coefficient of performance of a...Ch. 6.11 - Define the coefficient of performance of a heat...Ch. 6.11 - Prob. 34PCh. 6.11 - A refrigerator has a COP of 1.5. That is, the...Ch. 6.11 - In a refrigerator, heat is transferred from a...Ch. 6.11 - A heat pump is a device that absorbs energy from...Ch. 6.11 - What is the Clausius expression of the second law...Ch. 6.11 - Show that the KelvinPlanck and the Clausius...Ch. 6.11 - The coefficient of performance of a residential...Ch. 6.11 - A food freezer is to produce a 5-kW cooling...Ch. 6.11 - An automotive air conditioner produces a 1-kW...Ch. 6.11 - A food refrigerator is to provide a 15,000-kJ/h...Ch. 6.11 - Prob. 44PCh. 6.11 - Determine the COP of a heat pump that supplies...Ch. 6.11 - Prob. 46PCh. 6.11 - A heat pump with a COP of 1.4 is to produce a...Ch. 6.11 - An air conditioner removes heat steadily from a...Ch. 6.11 - A household refrigerator that has a power input of...Ch. 6.11 - When a man returns to his well-sealed house on a...Ch. 6.11 - Water enters an ice machine at 55F and leaves as...Ch. 6.11 - A refrigerator is used to cool water from 23 to 5C...Ch. 6.11 - A household refrigerator runs one-fourth of the...Ch. 6.11 - Consider an office room that is being cooled...Ch. 6.11 - A house that was heated by electric resistance...Ch. 6.11 - Refrigerant-134a enters the condenser of a...Ch. 6.11 - Refrigerant-134a enters the evaporator coils...Ch. 6.11 - An inventor claims to have developed a resistance...Ch. 6.11 - Prob. 60PCh. 6.11 - Why are engineers interested in reversible...Ch. 6.11 - A cold canned drink is left in a warmer room where...Ch. 6.11 - A block slides down an inclined plane with...Ch. 6.11 - Prob. 64PCh. 6.11 - Prob. 65PCh. 6.11 - Show that processes that use work for mixing are...Ch. 6.11 - Why does a nonquasi-equilibrium compression...Ch. 6.11 - Prob. 68PCh. 6.11 - Prob. 69PCh. 6.11 - What are the four processes that make up the...Ch. 6.11 - Prob. 71PCh. 6.11 - Prob. 72PCh. 6.11 - Prob. 73PCh. 6.11 - Somebody claims to have developed a new reversible...Ch. 6.11 - Is there any way to increase the efficiency of a...Ch. 6.11 - Consider two actual power plants operating with...Ch. 6.11 - You are an engineer in an electric-generation...Ch. 6.11 - Prob. 78PCh. 6.11 - A thermodynamicist claims to have developed a heat...Ch. 6.11 - A heat engine is operating on a Carnot cycle and...Ch. 6.11 - A completely reversible heat engine operates with...Ch. 6.11 - An inventor claims to have developed a heat engine...Ch. 6.11 - A Carnot heat engine operates between a source at...Ch. 6.11 - A heat engine is operating on a Carnot cycle and...Ch. 6.11 - A heat engine operates between a source at 477C...Ch. 6.11 - An experimentalist claims that, based on his...Ch. 6.11 - In tropical climates, the water near the surface...Ch. 6.11 - Prob. 89PCh. 6.11 - Prob. 90PCh. 6.11 - Prob. 91PCh. 6.11 - Prob. 92PCh. 6.11 - How can we increase the COP of a Carnot...Ch. 6.11 - In an effort to conserve energy in a heat-engine...Ch. 6.11 - Prob. 95PCh. 6.11 - Prob. 96PCh. 6.11 - A thermodynamicist claims to have developed a heat...Ch. 6.11 - Determine the minimum work per unit of heat...Ch. 6.11 - Prob. 99PCh. 6.11 - An air-conditioning system operating on the...Ch. 6.11 - A heat pump operates on a Carnot heat pump cycle...Ch. 6.11 - An air-conditioning system is used to maintain a...Ch. 6.11 - A Carnot refrigerator absorbs heat from a space at...Ch. 6.11 - Prob. 104PCh. 6.11 - A Carnot refrigerator operates in a room in which...Ch. 6.11 - Prob. 106PCh. 6.11 - A commercial refrigerator with refrigerant-134a as...Ch. 6.11 - Prob. 108PCh. 6.11 - A heat pump is to be used for heating a house in...Ch. 6.11 - A completely reversible heat pump has a COP of 1.6...Ch. 6.11 - A Carnot heat pump is to be used to heat a house...Ch. 6.11 - A Carnot heat engine receives heat from a...Ch. 6.11 - Prob. 113PCh. 6.11 - Derive an expression for the COP of a completely...Ch. 6.11 - Calculate and plot the COP of a completely...Ch. 6.11 - Prob. 116PCh. 6.11 - Prob. 117PCh. 6.11 - Prob. 118PCh. 6.11 - Someone proposes that the entire...Ch. 6.11 - Prob. 120PCh. 6.11 - Prob. 121PCh. 6.11 - Prob. 122PCh. 6.11 - It is commonly recommended that hot foods be...Ch. 6.11 - It is often stated that the refrigerator door...Ch. 6.11 - Prob. 125RPCh. 6.11 - Prob. 126RPCh. 6.11 - Prob. 127RPCh. 6.11 - A Carnot heat pump is used to heat and maintain a...Ch. 6.11 - A refrigeration system uses a water-cooled...Ch. 6.11 - A refrigeration system is to cool bread loaves...Ch. 6.11 - A heat pump with a COP of 2.8 is used to heat an...Ch. 6.11 - Prob. 132RPCh. 6.11 - Consider a Carnot heat-engine cycle executed in a...Ch. 6.11 - Prob. 134RPCh. 6.11 - Consider a Carnot refrigeration cycle executed in...Ch. 6.11 - Prob. 137RPCh. 6.11 - Consider two Carnot heat engines operating in...Ch. 6.11 - A heat engine operates between two reservoirs at...Ch. 6.11 - An old gas turbine has an efficiency of 21 percent...Ch. 6.11 - Prob. 141RPCh. 6.11 - Prob. 142RPCh. 6.11 - Prob. 143RPCh. 6.11 - The drinking water needs of a production facility...Ch. 6.11 - Prob. 145RPCh. 6.11 - Prob. 147RPCh. 6.11 - Prob. 148RPCh. 6.11 - Prob. 149RPCh. 6.11 - Prob. 150RPCh. 6.11 - Prob. 151RPCh. 6.11 - A heat pump with refrigerant-134a as the working...Ch. 6.11 - Prob. 153RPCh. 6.11 - Prob. 155RPCh. 6.11 - Prob. 156RPCh. 6.11 - Prob. 157RPCh. 6.11 - Prove that a refrigerators COP cannot exceed that...Ch. 6.11 - Consider a Carnot refrigerator and a Carnot heat...Ch. 6.11 - A 2.4-m-high 200-m2 house is maintained at 22C by...Ch. 6.11 - A window air conditioner that consumes 1 kW of...Ch. 6.11 - The drinking water needs of an office are met by...Ch. 6.11 - The label on a washing machine indicates that the...Ch. 6.11 - A heat pump is absorbing heat from the cold...Ch. 6.11 - A heat engine cycle is executed with steam in the...Ch. 6.11 - A heat pump cycle is executed with R134a under the...Ch. 6.11 - A refrigeration cycle is executed with R-134a...Ch. 6.11 - A heat pump with a COP of 3.2 is used to heat a...Ch. 6.11 - A heat engine cycle is executed with steam in the...Ch. 6.11 - A heat engine receives heat from a source at 1000C...Ch. 6.11 - An air-conditioning system operating on the...Ch. 6.11 - A refrigerator is removing heat from a cold medium...Ch. 6.11 - Two Carnot heat engines are operating in series...Ch. 6.11 - A typical new household refrigerator consumes...
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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 scientist claims to have developed a heat engine with 70% thermal efficiency when operating with thermal energy reservoirs at 700 K and 275 K. Is this claim valid? Please explain.arrow_forward1. What is the difference between Carnot efficiency and Actual efficiency? 2. What processes occur in a heat engine?arrow_forwardA heat pump is absorbing heat from the cold outdoors at 5 degrees celsius and supplying heat to a house at 22 degrees celsius at a rate of 18,000kJ/h. If the power consumed by the heat pump is 2.5kW, the coefficient of performance of the heat pump is?arrow_forward
- A Carnot heat engine receives heat from a reservoir at 900°C at a rate of 800 kJ/min and rejects the waste heat to the ambient air at 27°C. The entire work output of the heat engine is used to drive a refrigerator that removes heat from the refrigerated space at –5°C and transfers it to the same ambient air at 27°C. Determine the total rate of heat rejection to the ambient air.arrow_forwardA Carnot heat engine operates between a source at 1000 K and a sink at 300 K. If the heat engine is supplied with heat at a rate of 800 kJ/min, determine the power output of this heat engine and the thermal efficiency of the engine.arrow_forwardA heat engine is operating on a Carnot cycle and has a thermal efficiency of 55 percent. The waste heat from this engine is rejected to a nearby lake at 60°F at a rate of 800 Btu/min. Determine (a) the power output of the engine, in Hp and (b) the temperature of the heat source. Answers: 23.0608 hp; 695.5556°Farrow_forward
- An inventor claims to have developed a heat pump that produces a 200-kW heating effect for a 16°C heated zone while only using 80 kW of power and a heat source at 2°C. Justify the validity of this claim.arrow_forward1. A geothermal-based trigeneration plant produces 2.5 MW of electricity, 1.8 MW of process heat, and 1.4 MW of cooling. Electricity is produced for a period of 7500 h, heating for 2500 h, and cooling for 2000 h per year. The energy of geothermal plant consumed in the plant is 4 × 107 kWh during an entire year period. Determine the annual average utilization factor of this plant.arrow_forwardA 600-MW steam power plant, which is cooled by a nearby river, has a thermal efficiency of 40 percent. Deter- mine the rate of heat transfer to the river water. Will the actual heat transfer rate be higher or lower than this value? Why?arrow_forward
- Explain the principle of refrigerator? Show that a reversible heat engine acts as a refrigerator.arrow_forwardA heat engine operates between two reservoirs at 8000 C and 200 C. One-half of the work output of the engine is used to drive a Carnot heat pump that removes heat from the cold surroundings at 20 C and transfers heat to a house maintained at 220 C. If the house is losing heat at a rate of 62,000 kJ/h, determine the minimum rate of heat supply to the heat engine required to keep the house at 220 C.arrow_forwardA Carnot heat engine receives heat from a reservoir at 900°C at a rate of 800 kJ/min and rejects the waste heat to the ambient air at 27°C. The entire work output of the heat engine is used to drive a refrigerator that removes heat from the refrigerated space at –5°C and transfers it to the same ambient air at 27°C. Determine the maximum rate of heat removal from the refrigerated space.arrow_forward
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