Chapter 8, Problem 8.14DOEP

At steady state, a heat pump driven by an electric motor maintains the interior of a building at TH=293 K. The rate of heat transfer, in kJ/h, from the building through its walls and roof is given by 8000(TH-TC), where Tc is the outdoor temperature. Determine the minimum electric power, in kW, required to drive the heat pump for Tc = 276 K. (W cycle) min = i eTextbook and Media Save for Later kW Attempts: 0 of 5 used Submit Answer

Thermodynamics studies the relationship between temperature, energy, and work, and describes how energy changes from one form to another. A refrigeration cycle is a practical example of the application of thermodynamics. It is based on thermodynamic principles, such as energy conservation and heat transfer from a higher temperature region to a lower temperature region. The most common refrigeration cycle is the steam evolution cycle. It involves four main steps: upgrades, condensing, expanding, and evaporating.The study and understanding of thermodynamics are essential for designing efficient refrigeration systems, improving energy efficiency and understanding the behavior of refrigeration systems under different operating conditions. 2nd Step: Evaluate the performance of Refrigerator 2.Refrigerator 2 is a refrigerator that operates as an ideal vapor refrigeration cycle, and uses the same refrigerant fluid and the same evaporation and condensation temperatures as Refrigerator 1.In…

Thermodynamics studies the relationship between temperature, energy, and work, and describes how energy changes from one form to another. A refrigeration cycle is a practical example of the application of thermodynamics. It is based on thermodynamic principles, such as energy conservation and heat transfer from a higher temperature region to a lower temperature region. The most common refrigeration cycle is the steam evolution cycle. It involves four main steps: upgrades, condensing, expanding, and evaporating.The study and understanding of thermodynamics are essential for designing efficient refrigeration systems, improving energy efficiency and understanding the behavior of refrigeration systems under different operating conditions. 1st Step: Evaluate the performance of the Refrigerator 1.Refrigerator 1 operates as a reverse Carnot cycle using R-717 as refrigerant at a flow rate of 1.8 kg/s. The condensing and evaporating temperatures are 25 °C and -5 °C, respectively.To evaluate the…

You work as a maintenance engineer at Al-Hussein Thermal Power Station that produces electricity. It has a total generation capacity of 260 MW, which consists of two steam power plant units (2 x 130 MW). A. If the thermal efficiency of the first unit is 70%, and that of the second unit is 65%, determine the rate of the thermal energy required to operate the station. B. Determine the rate of waste heat rejection from the station. C. Determine the amount of waste heat energy rejected from the station if it has been operated for 12 hours. D. After certain maintenance operations, the efficiency of each unit is improved to become 80%: 1) How does this improvement affect the rate of thermal energy required to produce the same electrical power 260MW? Compare your answer with that obtained from part A 2) Calculate the rate of waste heat rejection after the improvement? Compare this value with that that obtained from part B. 3) Depending on your results in parts 1 and 2. How do you expect this…

Please atleast answer this question. I will upvote

Given that you are a policy maker in Davao, how will you rank the following in terms of the city's preference for renewable energy source, Geothermal, Wave or Biomass? Please back up your answers and explain in detail. Please consider pros and cons of each and their impacts in the community, economy, industry and environment.

= The owner of a propose steam power plant received bids from two fuel supplier. The first supplier offers coal whose ultimate analysis is: C = 71.5%, H = 5%, 0 = 7%, S = 3.6%, N = 1.3%, A = 8.2%, and M 3.4%. The other supplier offers natural gas whose HHV is 52.2MJ/kg and whose volumetric analysis is: 60% CH4, 30%C2H6, and 10%CO. Excess air for both cases is 20%. Other data for the power plant are: net output = 100MW, heat added at the boiler = 90% of energy chargeable, specific enthalpy in kJ/kg: turbine inlet = 3582.3, turbine outlet = 2251.881, pump inlet = 289.23, boiler inlet = 304.534. Atmospheric air temperature is 35C. Find possible steam consumption of this propose plant in kg/s.

b) A heat engine operates between two reservoirs at 800° C and 20° 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 2° C and transfers heat to a house maintained at 22° 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 22° C.

In your own words, define efficiency as it applies to a device designed to perform an energy transformation.