An ideal Rankine cycle operates between 2700 psia and 1050° F at throttle and 4 psia in the condenser. One high pressure open type feed-water heater and one low pressure open type feed water heater are placed at 700 psia and 190 psia respectively. a) Draw the schematic flow and T-S diagrams of the cycle [3] b) Calculate mass flow rate in the both heaters. [2] c) Calculate heat rejected. [2] d) Calculate cycle efficiency. [4] e) Calculate work ratio. [1] Assumption: 1 lbm/h flow at turbine throttle and no flow pressure drops.
In: Mechanical Engineering
Rankine cycle operates on boiler pressure 15 MPa and condenser pressure of 30 kPa. Superheated steam enters the high-pressure turbine at 450°C. The high-pressure turbine expands the steam and enters the re-heater at 2.5 MPa. The steam is reheated until temperature reaches 450°C before being expanded in low-pressure turbine to condenser pressure of 30 kPa. Assume the isentropic efficiency of the low-pressure and high-pressure turbines are 94% and 89% respectively, and pump is working isentropically. Neglect the change in kinetic energy, potential energy and pressure drops in boiler and condenser. The net power produced by the plant is 10 MW. Determine the followings: (a) Net heat supplied by boiler (in kJ/kg). [10 Marks] (b) Net heat rejected in condenser (in kJ/kg). [6 Marks] (c) Thermal efficiency of the cycle. [2 Marks] (d) Mass flow rate of the cycle (in kg/s). [1 Mark] (e) Thermal efficiency of the cycle if both turbines replaced with isentropic turbine. [6 Marks] (f) T-s diagram of the cycle with respect to the saturation lines. [5 Marks]
In: Mechanical Engineering
In: Mechanical Engineering
A rigid and closed steel tank with a volume of 86 dm 3 contains a mixture of saturated vapor and liquid at a quality and pressure of 0.9 and 20 bar respectively. Heat is removed from the system until it reaches 147 ° C.
In: Mechanical Engineering
Determine the adiabatic flame temperature when liquid octane, C8H18 at 25C is burned with 300% theoretical air at 25C in a steady flow process.
In: Mechanical Engineering
As a Mechanical engineer, to prevent building collapse from happen, Based on Engineering statics what factor should you take into account in designing the structure of the mall and if ever this incident(building collapse) happen how would you as an engineer react and solve this issue.
In: Mechanical Engineering
In: Mechanical Engineering
which is the reason why the equation is reached: dU = FcosΘds to describe the work done by a force.
Include descriptive schemes.
Write when the work is positive, negative or null depending on the angle between the force component and the displacement.
What is the unit of measurement of labor (U) in the international system and in the imperial system?
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Let's consider a four-cylinder engine with phase angles of 0o,90o,270,o180o. Commute mass for each cylinder 2kg, crank length 50 mm, connecting rod 250mm, distance between cylinder axes 150 mm. The crankshaft rotates at a constant speed of 800 rpm. According to the given, find the shaking moment acting on the motor block due to imbalance.
In: Mechanical Engineering
Consider a turbine; working substance is air.
cp=1.0 kJ/kgK , k=1.4
v1=0.03 , v2=0.08 m3/kg , p1=2.5 bar; state 1 is enterance, state 2 is the exit of the turbine. The turbine is not ideal (isentropic); the air goes through a state change according to pv^n=constant , n=1.6 Compute the ideal and actual specific works and turbine efficiency.
pvn=constant , n=1.6
In: Mechanical Engineering
Consider a 2nd order system with m=30kg, k = 5000N/m, c = 387N-s/m. Generate the BODE plot using MATLAB or Excel to find the maxima. If you do not have Excel, you can use google sheets. For MATLAB users these functions may be useful: (logspace, loglog)
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If TIG, MIG and arc welding are in consideration, which one is more suitable for robotic (automatic) welding? Why?
In: Mechanical Engineering
what would be the real life example of an elasticity please explain??
In: Mechanical Engineering
• Maintenance Management, Practices, Computerized Systems and future advancements.
please could you provide me with full description about each aspect.
In: Mechanical Engineering
Q2. A shaft carries four masses A, B, C and D of different magnitude and revolving at radii as mentioned below in planes measured from A at 300 mm, 400 mm and 700 mm. The angles between the cranks measured anticlockwise are A to B 450B to C 700 and C to D 1200 . The balancing masses are to be placed in planes X and Y. The distance between the planes A and X is 100 mm, between X and Y is 400 mm. If the balancing masses revolve at a radius of 250 mm, find their magnitudes and angular positions graphically.
i. The magnitude of mass X and Y
ii. The angular position of mass X and Y.
iii. Draw Space diagram.
iv. Couple Polygon
v. Force Polygon
vi. Tabular Column
Given :
In: Mechanical Engineering