The operators have noticed that the performance of the reactor is somewhat different to the design specifications and suspect that the thermal cycling may be responsible. The senior process engineer would like you to analyse two periods: - The period when the reactor is initially heated up and held at the operating temperature. - The period after the reactor is taken offline for maintenance and then heated up again. You should consider the effect of the tube expansion on the operating variables and the overall effect on pressure drop and conversion. Compare these responses to the estimated performance according to the design basis. You may include any equations or diagrams that you consider necessary to support your discussion. A numerical solution is not required. Hints: A general consideration of the design method for fixed bed reactors may reveal relationships between operating and performance variables.

The operators have noticed that the performance of the reactor is somewhat different to the design specifications and suspect that the thermal cycling may be responsible. The senior process engineer would like you to analyse two periods: - The period when the reactor is initially heated up and held at the operating temperature. - The period after the reactor is taken offline for maintenance and then heated up again. You should consider the effect of the tube expansion on the operating variables and the overall effect on pressure drop and conversion. Compare these responses to the estimated performance according to the design basis. You may include any equations or diagrams that you consider necessary to support your discussion. A numerical solution is not required. Hints: A general consideration of the design method for fixed bed reactors may reveal relationships between operating and performance variables.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter4: Numerical Analysis Of Heat Conduction

Section: Chapter Questions

Problem 4.1DP

See similar textbooks

Similar questions

The operators have noticed that the performance of the reactor is somewhat different to thedesign specifications and suspect that the thermal cycling may be responsible. The seniorprocess engineer would like you to analyse two periods:- The period when the reactor is initially heated up and held at the operating temperature.- The period after the reactor is taken offline for maintenance and then heated up again.You should consider the effect of the tube expansion on the operating variables and theoverall effect on pressure drop and conversion. Compare these responses to the estimatedperformance according to the design basis.You may include any equations or diagrams that you consider necessary to support yourdiscussion. A numerical solution is not required.
It is aimed to produce frozen potatoes in a newly established business. The entry temperature of the cleaned potato to the system is -16 °C, and the desired temperature to reach 10 °C. For this purpose, a refrigerant at -25 °C will be used. In the freezing process, potatoes of certain sizes are placed in the ice cream basket, the basket is immersed in the tank containing the refrigerant and kept during freezing. A cooling system is designed around the tank and 1M Joule per hour removes heat from the tank to keep the temperature of the tank constant at -25 °C. It is desirable to produce potatoes of different shapes. These shapes are spheres with a diameter of 20 mm, a cube with dimensions of 16x16x16 mm and a rectangular prism with a diameter of 12x12x25 mm. In such a process,a. What should be used as refrigerant?b. What is the daily production capacity for each product?c. What would you recommend to increase production capacity?
Hi, can you help me with the following problem? A thermally insulated tank of water 2 m x 2 m, depth 1 m is stirred with a paddle for threehours. If the paddle is driven by a motor whose shaft power is 8 kW determine the rate ofchange of temperature in degrees C per hr and the increase in temperature of the water.The specific heat of water is 4200 J/kgC. Identify a system and start your analysis from anappropriate form of the Fist Law of Thermodynamics
Discuss the concept of real-time thermal monityoring system.
A conditioned space has a calculated heat loss at the design maximum heating day of 10,000 BTUs / Hr to maintain an interior temperature of 70 F. We will use a hydronic baseboard style convector to heat the space. The style we have chosen comes in standard lengths. At rated temperature and flow of hydronic heating fluid for each 1 foot of length the heater will add 750 BTUs /Hr to the room. What length of heater can just maintain the temperature on the worst day? For this example we are ignoring other sources of heat loss such as ventilation or drafts.
Most automobiles have a coolant reservoir to catch radiator fluid that may overflow when the engine is hot. Such a radiator, made of copper, is filled to its 12-L capacity when at 10.0°C. -What volume of radiator fluid, in liters, will overflow when the radiator and fluid reach their 99.5°C operating temperature, given that the fluid’s thermal coefficient of volume expansion is 400.0 × 10-6 / °C? The coefficient of volume expansion for copper is 5.1 × 10-5 /°C.
Two inches of urethane foam will reduce heat loss close to 1000% when applied to a 2-inch diameter uninsulated steel pipe. Assume the pipe wall thickness is 0.25-inches, the pipe interior convective heat loss (hi) is 500 BTU/hr-ft2-oF, and the pipe outside convective heat loss ho 20 BTU/hr-ft2-oF, k steel is 25 BTU/hr-ft-oF, and k insulaton is 0.023 BTU/hr-ft-oF. (hint - calculate heat loss with and without insulation.
Build a spreadsheet to do the step by step method for estimating the temperature of unprotected steel work exposed to the ASTM E119 Standard Fire. Assume a convective heat transfer coefficient of 25 W/m2K and an emissivity of 0.5. Assume the specific heat to remain constant at 600 J/kgK. Use a time step of 30 seconds and an ambient temperature of 20°C. Provide an Excel plot showing the curves of the fire and a steel member through a time of 60 minutes with F/V ratios of: a)25 m-1 b)100 m-1 c)200 m-1 d)300 m-1 Note your plot should contain 5 curves. One for the fire and one for each of the F/V values. Also on the spreadsheet, highlight in green, the cells identifying the temperature of the unprotected steel member with an F/V of 200m-1 at the following times: a)3 minutes b)10 minutes c)20 minutes d)50 minutes
A closed stirred-tank reactor with two compartmentsis shown in Fig. The basic idea is to feed the reactants continuously into the first compartment, where they will be preheated by energy liberated in the exothermic reaction,which is anticipated to occur primarily in the second com-partment. The wall separating the two compartments is quite thin, thus allowing heat transfer; the outside of thereactor is well insulated; and a cooling coil is built intothe second compartment to remove excess energy liberated inthe reaction. Both tanks are completely full at all times.Tests are to be conducted initially with a single-component feed (i.e., no reaction) to evaluate the reactor’s thermalcharacteristics.(a)Develop a dynamic model for this process under the conditions of no reaction. Assume that q0,Ti,andTc all may vary.(b)Make a degrees of freedom analysis for your model—identifying all parameters, outputs, and inputs that must beknown functions of time in order to obtain a solution.(c)In…
4) One measure of the scale of a process is its throughputs of fuel or other input raw materials, e.g., lbs of coal per hour. Compare the coal throughputs for a small-scale experiment that uses 10 mg of coal in 6 seconds, and a single boiler in a large commercial-scale central-station electric generating plant. Assume: the commercial facility has a total output of 1,020 MW e supplied by three boilers of equal capacity; the boiler has a heat rate of (8,980 Btu th /hr)/(kW e ) based on fuel HHV, and fires coal with a gross heating value (i.e., HHV) of 14,000 Btu th /lb.
Residual oil, with a heating value of 18,480 BTU/lbm, is used as a fuel in a power plant which produces 947,870 BTU/s of electricity. The overall efficiency of the power plant is 52%. Determine the: a. Heat input, in BTU/s b. Daily fuel consumption, in lbm c. Dimensions of the cylindrical storage (assuming length is equal to the diameter), in ft. d. Heat rejected to the environment, in BTU/s. The density of the oil is 62 lbm/ft3
Figure below shows a steam jet refrigeration system that produces chilled water in a flash chamber. The chamber is maintained at a pressure by the steam ejector, which removes the vapor generated by entraining it in the low-pressure jet and discharging into the condenser. The vacuum pump removes air and other non-condensable gases from the condenser shell. For the conditions shown on the figure, determine the make-up water and cooling water flow rates in kg/hr. Show diagrams if there are any