300% excess air having a dry bulb temperature of 25 degree celsius and relative humidity of 60% is used to fully combust 1 kg/hr of methane in a boiler and the heat of reaction is used to generate steam. Hot water enters the boiler as a saturated liquid at 102 degree celsius and leaves as superheated at 40 bar and 400 degree celsius.

The combusted gases leave the boiler at 450 degree celsius and are then cooled to 25 degree celsius causing some of the water in the gas to condense.

Assuptions:

The combustion reaction takes place at 450 degree celsius.

The combusted gases can be assumed to have the properties of air.

The heat capacity of air can be assumed constant at an average temperature of 225 degree celsius.

so, what is the moisture content of the incoming air on a dry basis? and how much energy is transferred during the cooling of the combusted gases?

At the beginning of the compression process of an air standard Otto cycle, p₁ = 1 bar, T₁ = 300 K. The maximum temperature in the cycle is 2250 K and the compression ratio is 9.8. The engine has 4 cylinders and an engine displacement of V_d = 2.7 L. Determine per cylinder:

c)    the heat addition per cycle, in kJ.
d)    the heat rejection per cycle, in kJ.
e)    the net work per cycle, in kJ.
f)     the thermal efficiency.
g)    the mean effective pressure, in bar.

In what ways could the U.S. government encourage the use of more environmentally-friendly fuels?

Saturated propane vapor at 200 psia is fed to a well-insulated heat exchanger at a rate of 2600 standard cubic feet per hour. The propane leaves the exchanger as a saturated liquid (a liquid at its boiling point) at the same pressure. Cooling water enters the exchanger at 70 oF. Flowing concurrently (in the same direction) with the propane. The temperature difference between the outlet streams (liquid propane and water) is 15 oF.

Estimate the required flow rate (lbm/h) of the water to take away the heat from exchanger. (you will need to write two separate energy balances.) Assume the heat capacity of liquid water is constant at 1.0 Btu/(lbm.oF) and neglect heat losses to the outside and the effects of pressure on the heat of evaporation of propane.

3. An insulated container contains 2.7 kg of steam at 1.4 bar and 120°C. The top is opened and a 1.8 kg block of ice at 0°C and 4.5 kg of liquid water at 1.6°C are dumped into the container. What is the final temperature of the resulting vapor-liquid mixture in the container? Note: It takes 6.0095 KJ/mol to melt ice.

During a reversible non-flow process, a cylinder containing 0.075 kg of fluid having pressure of 1.2 bar, a volume of 0.07 m³ and specific internal energy of 180 kJ/kg undergoes a steady polytropic compression process. The steady final pressure , volume and specific internal energy are 9.5 bar, 0.0125 m³ and 350 kJ/kg respectively.

Calculate

1. The compression index n
2. The work required for the compression
3. The quantity and direction of heat energy                              

Assume it was a steady isothermal (hyperbolic) compression process with final volume 0.0125 m³. Calculate

4. Pressure at the final state
5. The work required for the compression
6. The quantity and direction of heat energy

Write a three paragraphs to summarize current efforts and challenges aimed at producing green concrete. (150 words minimum)

List two methods that are used in heat exchanger design and analysis.

(Q2) As a fire engineer, assume that you are assigned to a fire engineering design of the retail building with extraordinary atrium that connected six floors. You have to adopt fire engineering approach on this project and conduct a theoretical analysis of full evacuation in this commercial building. Please brief your design procedures. (Hint: Relationship between occupant density, travel speed and flow is recommended to consider.)

What are the latest technologies to remove sulfate from industrial wastewater?