1- At NYIT in 1993 a 100ton electric A/C system (electric driven compressor) with a 100 ton natural gas absorption system. Electric then was$. 12/kwh and the natural gas unit was expected to have the energy cost. Other date is listed below. Make a financial analysis and decide if a replacement is worth it. Lifespan of electric system=10 years and salvage S=0; Lifespan of the absorption system is 20 years and S=0(even after 10years) Energy savings = 50% of electric; Maintenance Cost/yr, gas $6000/yr: Initial cost of electric=0 (sunk cost), gas $6000 and the installation is additional $20,000. Gov’t funding is 30% of the initial cost. The may assume any other unknown factors. On a quantitative basis is the switch justified. Work the problem out either on a present value basis for 10 years or annuitized cost per year for the same time period. 2- On a qualitative basis the decision may be affected by: a. Lack f proper maintenance and staff. b. Warnings from other consumers that the system is “trouble”. They were told that JFK A/C system converted to gas then switched to electric. c. The unit required much more control devices that were not that reliable as electric. d. The new system would be difficult to computerize and automate. e. Unknown problems may arise as the unit was not that well time tested. With all this in mind, how would the decision would be affected? Keep in mind that inflation is a plus for the gas system. 3- a. A brick wall 4” facebrick (water-proof), 4 back brick is to have a 2” layer polyurethane (1/k=6.75) added. Find the percentage in drop of heat loss. b. These walls currently lose in heating $12000/yr. How much can be by this insulations? c. For a pay back period of 4 years what is the maximum upfront cost? 4- a. A room is kept in summer at 75F and 70RH (muggy day) what % of people will be uncomfortable? (Hint-the center of the comfort zone is 100% comfort at the edge it drops to 10%. Use extrapolation to find the % occupants uncomfortable) b. How is clothing entered in the comfort? c. How is clothing entered in the comfort? d. Why are heated buildings in winter often too dry (low humidity) 5- a. A room of 10,000cu ft is at 40F and is to be heated to 70F in one (1) hour. The walls lose an average of 20BTU/min. Compute the minimum wattage of the heater. b. The heater produces heat at a constant temperature of 249F (700R). Consider the “sink” temperature at 70F (550). What % of the heat supplied is useful? Density air=.075 #/cu ft, Cp = .24BTU/#-F What % of the heat supplied is useful? Density air=.075 #/cu ft, Cp = .24BTU/#-F 6- Submit the cooling load analysis of your room either in house or apartment. This is essentially the same problem assigned for home work and can be submitted here. You can also use the form in the text which is simpler. 7- The 10/18/10 issue of the Wall street Journal had a lengthy series of articles on “Electric Cars” in which some experts claim the vehicle is not economic until gas gets to $9-10 a gallon. How would you support this analysis? Note this analysis also includes “green” effects since most of these cars re powered by electric generated by coal. However the writers ignored the effect that they can be powered at night when electric is cheap and power plants do not have to cut out boilers — a big, big energy waste.
email@example.com Operations Team Whatsapp( +91 9911743277) 1- At NYIT in 1993 … Read More...
1 MECE2320U-THERMODYNAMICS HOMEWORK # 5 Instructor: Dr. Ibrahim Dincer Assignment Date: Thursday, 22 October 2015 Assignment Type: Individual Due Date: Thursday, 29 October 2015 (3.00 pm latest, leave in dropbox 8) 1) As shown in figure, the inlet and outlet conditions of a steam turbine are given. The heat loss from turbine is 35 kJ per kg of steam. a) Show all the state points on T-v diagram b) Write mass and energy balance equations c) Calculate the turbine work 2) As shown in figure, refrigerant R134a enters to a compressor. Write both mass and energy balance equations. Calculate the compressor work and the mass flow rate of refrigerant. 3) As shown in figure, the heat exchanger uses the heat of hot exhaust gases to produce steam. Where, 15% of heat is lost to the surroundings. Exhaust gases enters the heat exchanger at 500°C. Water enters at 15°C as saturated liquid and exit at saturated vapor at 2 MPa. Mass flow rate of water is 0.025 kg/s, and for exhaust gases, it is 0.42 kg/s. The specific heat for exhaust gases is 1.045 kJ/kg K, which can be treated as ideal gas. 1 Turbine 2 ? 1 = 1 ??/? ?1 = 1 ??? ?1 = 300 ℃ ?1 = 40 ?/? ? ??? =? ????? = 35 ??/?? ?2 = 150 ??? ?2 = 0.9 ?2 = 180 ?/? 1 Compressor 2 ???? ???? = 1.3 ?3/??? ?1 = 100 ??? ?1 = −20 ℃ ? ?? =? ? ???? = 3 ?? ?2 = 800 ??? ?2 = 60 ℃ 2 a) Write mass and energy balance equations. b) Calculate the rate of heat transfer to the water. c) Calculate the exhaust gases exit temperature. 4) As shown in figure, two refrigerant R134a streams mix in a mixing chamber. If the mass flow rate of cold stream is twice that of the hot stream. a) Write mass and energy balance equations. b) Calculate the temperature of the mixture at the exit of the mixing chamber c) Calculate the quality at the exit of the mixing chamber 5) As shown in figure, an air conditioning system requires airflow at the main supply duct at a rate of 140 m3/min. The velocity inside circular duct is not to exceed 9 m/s. Assume that the fan converts 85% of electrical energy it consumes into kinetic energy of air. a) Write mass and energy balance equations. b) Calculate the size of electric motor require to drive the fan c) Calculate the diameter of the main duct ?2 = 1 ??? ?2 = 90 ℃ ?1 = 1 ??? ?1 = 30 ℃ ?3 =? ?3 =? 140 ?3/??? 9 ?/? Air Fan
One of the differences between a voltaic cell and an electrolytic cell is that in an electrolytic cell __________. A) an electric current is produced by a chemical reaction B) electrons flow toward the anode C) a nonspontaneous reaction is forced to occur D) O2 gas is produced at the cathode E) oxidation occurs at the cathode
C) a nonspontaneous reaction is forced to occur One of … Read More...
Copper reacts with nitric acid to produce copper(II) nitrate, nitrogen dioxide gas, and water. Cu(s) + 4 HNO3(aq) Cu(NO3)2(aq) + 2 NO2(g) + 2 H2O() If you have 0.500 moles of Cu you need at least 2.00 moles of HNO3 to produce 0.500 moles of Cu(NO3)2. you need at least 2.00 moles of HNO3 to produce 1.00 moles of Cu(NO3)2. you need at least 2.00 moles of HNO3 to produce 2.00 moles of Cu(NO3)2. you need at least 0.250 moles of HNO3 to produce 0.500 moles of Cu(NO3)2. you need at least 0.125 moles of HNO3 to produce 0.500 moles of Cu(NO3)2.
Chapter 03 Reading Questions Due: 11:59pm on Friday, May 23, 2014 You will receive no credit for items you complete after the assignment is due. Grading Policy Chapter 3 Reading Quiz Question 1 Part A Isotopes of an element differ from each other by the _____. ANSWER: Correct Chapter 3 Reading Quiz Question 2 Part A Which one of the following statements about pH is correct? ANSWER: Correct Lemon juice is an acid. Chapter 3 Reading Quiz Question 17 Part A In which form are water molecules most closely bonded to each other? ANSWER: number of electrons number of neutrons types of electrons number of protons Stomach acid has more OH- ions than H+ ions. Baking soda has more H+ ions than OH- ions. Lemon juice has more H+ ions than OH- ions. Seawater is slightly acidic. Chapter 03 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 1 of 9 5/21/2014 7:58 PM Correct Chapter 3 Reading Quiz Question 16 Part A Which one of the following is a molecule but NOT a compound? ANSWER: Correct Oxygen is a molecule made up of just one element. Therefore, it is not a compound. Chapter 3 Reading Quiz Question 3 Part A Which one of the following is a carbohydrate and one of Earth’s most abundant organic molecule? ANSWER: Correct equally closely bonded in water vapor and ice solid ice forming part of an Antarctic sheet liquid water a few degrees above the freezing point water vapor above a boiling pot of water CH4 O2 CO2 H2O oil protein cellulose DNA Chapter 03 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 2 of 9 5/21/2014 7:58 PM Chapter 3 Reading Quiz Question 4 Part A Which one of the following is a protein that functions as a catalyst? ANSWER: Correct Chapter 3 Reading Quiz Question 18 Part A The process of translation involves the use of _____. ANSWER: Chapter 3 Reading Quiz Question 5 Part A The cooling effect of sweating best represents _____. ANSWER: glucose cellulose enzyme RNA proteins to make lipids lipids to make carbohydrates carbohydrates to make proteins nucleic acids to make proteins latent heat transfer conduction radiation convection Chapter 03 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 3 of 9 5/21/2014 7:58 PM Correct Chapter 3 Reading Quiz Question 6 Part A When plants use sunlight in photosynthesis, the plants are using a form of _____. ANSWER: Correct Chapter 3 Reading Quiz Question 8 Part A Which of the following converts mass to energy? ANSWER: Correct Chapter 3 Reading Quiz Question 19 Part A When a windmill turns to generate electricity, the amount of kinetic energy input _____. ANSWER: chemical energy in sunlight nuclear fission electromagnetic radiation conduction conduction the breaking of chemical bonds nuclear fission photosynthesis Chapter 03 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 4 of 9 5/21/2014 7:58 PM Correct Chapter 3 Reading Quiz Question 20 Part A Which of the following best represents kinetic energy? ANSWER: Correct Chapter 3 Reading Quiz Question 21 Part A Which of the following processes reduces entropy? ANSWER: Correct Chapter 3 Reading Quiz Question 9 is unrelated to the amount of electrical energy produced is more than the amount of electrical energy produced equals the amount of electrical energy produced is less than the amount of electrical energy produced a charged battery gunpowder in a bullet the energy in the wax molecules of a candle a hot burner on a stove burning gasoline in an automobile engine photosynthesis in a leaf a person walking up a flight of stairs cell respiration in a leaf Chapter 03 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 5 of 9 5/21/2014 7:58 PM Part A Which one of the following planets is a gas giant? ANSWER: Correct Chapter 3 Reading Quiz Question 10 Part A What is the main driving force that causes Earth’s tectonic plates to drift? ANSWER: Correct Chapter 3 Reading Quiz Question 23 Part A In which of the following locations would you expect to find large quantities of young rocks? ANSWER: Venus Jupiter Mars Mercury Heat from Earth’s core causes the mantle rock to circulate. The weight of the tectonic plates causes them to sink and melt. Currents of magma from the core of Earth circulate just beneath the tectonic plates. Electromagnetic radiation from the sun heats the tectonic plates, causing them to expand. the Appalachian Mountains the Himalayas deep in the central parts of India the Mid-Atlantic Ridge Chapter 03 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 6 of 9 5/21/2014 7:58 PM Chapter 3 Reading Quiz Question 12 Part A The oxygen-rich atmosphere of Earth is mainly the result of _____. ANSWER: Correct Chapter 3 Reading Quiz Question 13 Part A A scientist working on the chemical reactions in the ozone layer is studying the _____. ANSWER: Correct Chapter 3 Reading Quiz Question 24 Part A The total amount of moisture in the air is highest when relative humidity is _____. ANSWER: volcanic activity chemical reactions between the early Earth atmosphere and iron photosynthetic organisms erosion of rocks into soil troposphere thermosphere stratosphere mesosphere Chapter 03 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 7 of 9 5/21/2014 7:58 PM Chapter 3 Reading Quiz Question 15 Part A You are enjoying a spring day but expect a storm to arrive soon . As the storm arrives and the rain begins to fall, you notice that the temperature drops dramatically. Most likely, you have just experienced the arrival of a _____. ANSWER: Correct Chapter 3 Reading Quiz Question 25 Part A Every day tremendous amounts of the sun’s energy strikes Earth. Why doesn’t Earth overheat? ANSWER: Correct Earth’s energy budget is balanced. Over the course of a year, the energy input is equal to the energy output. Chapter 3 Reading Quiz Question 7 low and temperatures are low high and temperatures are high high and temperatures are low low and temperatures are high cold front Hadley cell intertropical convergence stratospheric event The energy is ultimately radiated back to space. Much of the heat melts rocks, forming lava deep inside of Earth. Most of the energy is used in photosynthesis to help plants grow and survive. The energy mostly is absorbed in various weather systems. Chapter 03 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 8 of 9 5/21/2014 7:58 PM Part A How many calories are required to heat up 1,000 grams of liquid water (about 1 liter) from 20 °C to 70 °C? ANSWER: Correct Chapter 3 Reading Quiz Question 14 Part A Hadley cells near the Equator consist of _____. ANSWER: Correct Score Summary: Your score on this assignment is 85.5%. You received 19.67 out of a possible total of 23 points. 100 1,000 5,000 50,000 rising dry air associated with deserts and falling moist air that produces precipitation and rainforests rising moist air that produces precipitation and rainforests, and falling dry air associated with deserts warm, moist air rising up the sides of mountains and cool, dry air descending on the leeward sides cool, dry air rising up the sides of mountains and warm, moist air descending on the leeward sides Chapter 03 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 9 of 9 5/21/2014 7:58 PM
The reaction of 50 mL of 2 Cl gas with 50 mL of 4 CH gas via the equation: 2 4 3 Cl (g) + CH (g)®HCl (g) + CH Cl (g) will produce a total of __________ mL of products if pressure and temperature are kept constant. A) 100 B) 50 C) 200 D) 150 E) 250
Question 2 0 / 1 point The formation of our solar system began when electrons settled into orbit around hydrogen nuclei water condensed into an icy body a shock wave from a nearby exploding star started a cloud of dust and gas spinning all matter and energy exploded from a tiny singularity in the big bang
F6.1 Piloted ignition occurs when the lower flammable limit is reached in the gas phase in the vicinity of the ignition pilot. True False F6.2 The flashpoint of a liquid fuel is always lower than its boiling point. True False F6.3 The vapor concentration just above the surface of a boiling liquid is 100%. True False F6.4 The autoignition temperature of a liquid fuel is close to its boiling point. True False F6.5 Piloted ignition of solid fuels typically occurs at surface temperatures ranging from 250°C to 400°C, while autoignition temperatures usually exceed 500°C. True False F6.6 Except for very low heating conditions, the physical thickness of objects that exhibit “thin” piloted ignition behavior is typically of the order of 0.1-0.2 mm. 1-2 mm. 10-20 mm. F6.7 The time to piloted ignition of a “thin” object is proportional to the inverse of the net heat flux at its exposed surface. True False F6.8 The time to piloted ignition of a “thick” object is proportional to the inverse of the net heat flux at its exposed surface. True False
1 REQUIREMENTS You will need to complete the following tasks and deliver your finding in a written report by August 6th. Research the six scenarios given below in option 1 for added capacity to uncover any additional costs/benefits to society these options might pose. Write a two page summary describing each scenario. Discuss the pros and cons of each scenario, including such items as renewable sources of fuel, environmental factors, etc. Give examples of each type of project by name and location and indicate the sources of your information. Please use either IEEE or APA style. Do an economic analysis of the six scenarios. Use a 20-year period and assume an inflation rate of 4 percent. Include your calculations and any assumptions in the report. Also answer the following questions: Which scenario is the best from an economic basis? Are there any other considerations, such as environmental/health/social issues, which should be considered? Which scenario have you selected based on the answers to a and b? What is the estimated timeframe to implement the different options? (base your timelines on existing projects of similar size if possible, use MS Project/Project Libre to generate the timelines) Make a recommendation regarding the best option for the utility. 2 Situations A utility company in one of the western states is considering the addition of 50 megawatts of generating capacity to meet expected demands for electrical energy by the year 2025. The three options that the utility has are: Add generating capacity. Constructing one of the scenarios below would do this. Purchase power from Canada under terms of a 20-year contract. Do neither of the above. This assumes that brownouts will occur during high demand periods. The utility presently has 200 megawatts of installed capacity and generates an average of 1.2 billion kilowatt-hours annually. Maximum generation capability is 1.3 billion kW-hours. By the year 2025, this reserve of 100,000,000 kW-hours will be used. 2.1 OPTION 1 – ADD GENERATING CAPACITY For this option there are six possible scenarios: Hydroelectric dam. Initial cost is $ 50 million. Annual operating and maintenance cost is $ 1.7 million. Project life is 30 years before a major rebuild is required. Wind farm. Initial cost is $ 28 million. Annual operating and maintenance cost is $ 2.5 million. Project life is 12 years. At this time new equipment will be required. Solar power. Initial cost is $ 32 million. Annual operating and maintenance cost is $ 1.1 million. Project life is 10 years. Natural gas turbines. Initial cost is $ 14 million. Annual operating and maintenance cost is $2.0 million. Project life is 12 years. Nuclear plant. Initial cost is $ 70 million. Annual operating and maintenance cost is $ 2.0 million. Project life is 25 years. Coal-fired turbines. Initial cost is $ 35 million. Annual operating and maintenance cost is $ 2.7 million. Project life is 28 years. 2.2 OPTION 2 – BUY POWER FROM CANADA The annual additional energy requirement is 350,000,000 kilowatt-hours. The cost of energy from Canada is 1.48 cents per kilowatt-hour for the first year. The price will be escalated at 4 percent annually for the 20-year contract period. 2.3 OPTION 3 – DO NOTHING Local municipalities are very opposed to this option since companies may have to close down for short periods of time. Also, it would be very difficult to attract new businesses. If nothing is done, by the year 2025 it is anticipated that some companies will be without power for short periods of time during the summer months. These are known as brownouts. It is estimated, based on historical data that these outages will occur once a week during July and August for periods of 6 hours.