THIS ASSIGNMENT HAS 2 PARTS and a READING ASSIGNMENTMicrosoft Word - ENSY_5000_2022_Fall_HW_08.docx ENSY 5000 Fundamentals of Energy System Integration Homework Problem Set 8 Submit your assignment as a pdf file to the Canvas for submission portal allocated for this Homework. NOTE: To solve this problem set as well as any other problem set, it will help if you draw your system and identifying the energy component (property) changes and the energy interactions at the boundaries. In some cases, you may need a sub system analysis to identify the energy interactions. In all your solutions, clearly show your system definition with proper sketches indicating related energy flows clearly show how you write your equations (e.g., Mass, Energy, Entropy balance, etc.) identify relevant energy flows use of definitions of power-energy relationships and efficiencies as needed use of proper equation of state, or property relations as needed clearly show your steps, assumptions, and approximations. READING ASSIGNMENT: Read Chapter 10 “Development of Sustainable Technology: Metrics From Thermodynamics” of the Textbook. PART 1 Q1: In Homework Assignment set #7, question 7 included a turbine with hot air exhaust at 753 K temperature and 1 bar pressure. Suppose exhaust air can be used to heat water using a heat exchanger as a waste heat recovery system. A heat exchanger is a device in which a hot fluid is used to heat a cold fluid flow as it is shown in the figure below. The hot and cold fluids do not mix and there are two inlets and two exits in this device. Assume outside of the heat exchanger is well insulated such that heat from heat exchanger to surrounding is negligible (see figure). Only heat interactions are between fluids passing through the heat exchanger. Effectiveness, , of such heat exchangers are defined as ? ?? Where qact is the actual amount of heat passes from hot to cold fluid, and it can be found by applying energy balance to a system boundary covering either hot fluid (as marked on the figure) or cold fluid. qMaxPossible is the maximum possible amount of heat that can be passed from the hot to cold fluid, and it can be found from ? ? ? , ? , Where Cmin is the minimum of heat capacities of cold and hot fluids as follows ? min ? ? ,? ? Here ? and ? are specific heat capacities of cold and hot fluids, respectively. In the proposed heat recovery system, turbine exhaust flows on the hot side of the heat exchanger and exits to the surroundings. On the colder side, water enters at 393 K at a rate of 0.04916 kg/s, and it exits at a higher temperature. Effectiveness of the heat exchanger is 80%. Pressure inside the heat exchanger is constant at 1 bar assuming pressure drop inside the heat exchanger is negligible. Assume dead state is at 293 K and 1 bar to answer following questions. A) What are the exit temperatures of the air and heated water after they pass through recovery heat exchanger? B) Find the entropy production rate in the heat exchanger (treat both hot and cold sides as internal parts of the heat exchanger) C) Find the exergy destruction rate in the heat exchanger (treat both hot and cold sides as internal parts of the heat exchanger) D) Find the entropy production rate of the air after it leaves the heat exchanger and reaches equilibrium with the surroundings, compare the result with HW7 E) Find the exergy destruction rate of the air after it leaves the heat exchanger and reaches equilibrium with the surroundings, compare the result with HW7 F) Determine the first law efficiency or Energy Utilization Factor for this heat exchanger. You can consider, product (desired output) is the energy increase at the cold side and the required input is the energy decrease (or provided) by the hot side (air passing through the heat exchanger). G) Determine the second law (exergetic) efficiency of this device. You can consider, product (desired output) is the exergy increase in the cold side and the required input is the exergy decrease (or provided by) the hot side (air passing through heat exchanger). H) Compare the entropy production and exergy destruction for the exhaust air with and without heat recovery system to decide if such heat recovery system is feasible. What would be maximum acceptable installment cost of such heat recovery system If it can operate 24 hours a day and 360 days a year, it has 8-year operational life, and cost of exergy is $0.10/kWh. Please note that in the question we did not include pump and fan that may be necessary to pass the fluids through the heat exchanger, and we did not include the cost of the heat exchanger. PART 2 Q2: Consider a gas turbine power cycle operating similar to a Brayton Cycle. Compression ratio is 4. The isentropic efficiencies of the turbine and compressor are both 75%. Pressure drop in the combustor is negligible. The combustor exit temperature is 1600 K. Pressure and temperature of surrounding atmospheric air is 1 bar and 290 K, respectively. Net power output is 500 kW. Assume treat air as an ideal gas with constant specific heats with following properties. R=0.287, cp=1.075, cv=0.788 all in kJ/kg∙K. Apply air-standard analysis like we have done in examples 18 to 20. Determine A) actual temperatures and pressures in all four principal states if this gas power cycle. B) power required to run the compressor, power developed by the turbine, per kg of air passing through (i.e., in kJ/kg). C) mass flow rate of air circulating through the components in kg/s. D) Rate of heat input in the combustion chamber and rate of heat rejected from the cycle, in kW. E) Rate of exergy equivalent of heats in part D, in kW. F) thermal and exergetic efficiencies of this power cycle. G) flow exergy of air at all 4 states, and exergy destruction in all 4 components of this gas power cycle (you can treat exhaust and intake as a virtual heat exchanger). H) Make a exergy accounting table and list exergy dispositions from larges to smallest similar to the one we have done for example 19. Q3: Convert the power cycle in Q2 to a regenerative power cycle by including a regenerative heat exchanger. Assume regenerator effectiveness is 80% (you can use the same effectiveness formula in Q1). A) actual temperatures and pressures in all six principal states (regenerator will add 2 more states in addition to the ones in Q2). B) mass flow rate of air circulating through the components in kg/s. C) Rate of heat input in the combustion chamber and rate of heat rejected from the cycle, in kW. D) Rate of exergy equivalent of heats in part C, in kW. E) thermal and exergetic efficiencies of this power cycle. F) Find flow exergy of air at all 6 states, and exergy destruction in all 5 components of this cycle. G) Make an exergy accounting table and list exergy dispositions from larges to smallest similar to the one we have done for example 19.