Steam at 0.4 MPa, 300 °C, enters an adiabatic nozzle with a low velocity and leaves at 0.2 MPa with a quality of 90%. Find the exit velocity.*a) Exit velocity = 1200 m/sb) Exit velocity = 956 m/sc) Exit velocity = 1000 m/sd) Exit velocity = 1078 m/s
Question
Steam at 0.4 MPa, 300 °C, enters an adiabatic nozzle with a low velocity and leaves at 0.2 MPa with a quality of 90%. Find the exit velocity.*a) Exit velocity = 1200 m/sb) Exit velocity = 956 m/sc) Exit velocity = 1000 m/sd) Exit velocity = 1078 m/s
Solution
To solve this problem, we need to use the principle of conservation of energy, which is often expressed in the form of the First Law of Thermodynamics. For a steady-flow system such as a steam nozzle, the energy equation simplifies to:
h1 + (V1^2)/2 = h2 + (V2^2)/2
where h1 and h2 are the specific enthalpies at the inlet and outlet, respectively, and V1 and V2 are the velocities at the inlet and outlet, respectively.
Given that the inlet velocity is low, we can assume V1 is approximately 0.
We are given the pressure and temperature at the inlet, so we can look up h1 in the steam tables. At 0.4 MPa and 300 °C, h1 is approximately 3051.2 kJ/kg.
At the outlet, we are given the pressure and the quality (x), so we can find h2 using the equation:
h2 = hf + x*hfg
where hf is the specific enthalpy of saturated liquid and hfg is the specific enthalpy of vaporization, both at the outlet pressure of 0.2 MPa. From the steam tables, hf is approximately 504.7 kJ/kg and hfg is approximately 2201.9 kJ/kg. So, with x = 0.9, we find h2 is approximately 2503.5 kJ/kg.
Substituting these values into the energy equation gives:
3051.2 kJ/kg = 2503.5 kJ/kg + (V2^2)/2
Solving for V2, we find V2 is approximately 956 m/s. So, the correct answer is (b) Exit velocity = 956 m/s.
Similar Questions
The fluid velocity at the exit of a nozzle is 280 m/s. The velocity is 346 m/s. Determine the Mach number for the flow.Group of answer choices0.2361.2361.8090.809
A steam turbine operates under steady flow conditions, receiving steamat 1.2MPa and 1880C, and enthalpy 2785kJ/kg, velocity 33.3m/s andelevation 3m. Steam leaves the turbine at 20 kPa, and 2512kJ/kg, velocity100m/s and elevation zero m. Heat is lost to surroundings at the rate of0.29kJ/s. If the rate of steam flow through the turbine is 0.42kg/s, what isthe power output of the turbine?
Water leaves a nozzle of area 0.01 m2 at a velocity of 2 m per second. What is the mass flow rate of the water if the density is 1000 kg/m3?
Superheated steam enters an adiabatic turbine at 10 MPa and 500 °C, and exits at 4 MPa. The final temperature is closest to:Question 7Select one:a.326 °Cb.371 °Cc.365 °Cd.354 °C
Water is flowing in a fire hose with a velocity of 1.0 m/s and a pressure of 200000Pa. At the nozzle the pressure decreases to atmospheric pressure (101300 Pa), thereis no change in height. Use the Bernoulli equation to calculate the velocity of thewater exiting the nozzle. (Hint: The density of water is 1000 kg/m3 and gravity g is9.8 m/s2. Pay attention to units!)]a.12 m/sb.13 m/sc.7m/sd. 14m/s
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.