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an air compressor takes in air at 100 kpa and 290 k and delivers it at 1 mpa. the compressor operates under steady-state conditions with a work input of 209kj/kg. subsequently, the comppressed air undergoes further proceesing in a constant-pressure cooler, where heat is transferred from the air to the surroundings, amounting to 207 kj/kg. neglecting kinetic and potential energy effect, determine the temperature at state 2, in k

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Final answer:

To find the temperature at state 2, we need to consider the changes in the work input and heat transfer in the system. The work input into the compressor is 209 kJ/kg, and the heat transfer in the cooler is 207 kJ/kg. The temperature at state 1 (initial state) is given as 290 K. Using the ideal gas law and the specific heat at constant volume, we can calculate the temperature at state 2 to be approximately 292.78 K.

Step-by-step explanation:

To find the temperature at state 2, we need to consider the changes in the work input and heat transfer in the system. The work input into the compressor is 209 kJ/kg, and the heat transfer in the cooler is 207 kJ/kg. The temperature at state 1 (initial state) is given as 290 K. Using the equation for work and heat, we can determine the temperature at state 2.

First, we calculate the change in internal energy (ΔU) of the system by subtracting the heat transfer from the work input: ΔU = Work input - Heat transfer = 209 kJ/kg - 207 kJ/kg = 2 kJ/kg.

Next, we use the ideal gas law to find the change in temperature (ΔT) using the formula ΔU = C_v × ΔT, where C_v is the specific heat at constant volume. Rearranging the formula, we can solve for ΔT: ΔT = ΔU / C_v. The specific heat at constant volume for an ideal gas is given by C_v = R/(γ-1), where R is the gas constant and γ is the specific heat ratio. Assuming air is an ideal gas with γ = 1.4, the gas constant R = 0.287 kJ/kg-K can be used.

Substituting the given values, we have: ΔT = (2 kJ/kg) / (0.287 kJ/kg-K / (1.4 - 1)) = 2 / 0.287 × 0.4.

ΔT ≈ 2.78 K.

Therefore, the temperature at state 2 is approximately 290 + 2.78 ≈ 292.78 K.

To determine the temperature at state 2 after compression and cooling, the first law of thermodynamics would usually be applied; however, given the problem states that the heat removed is almost equal to the work done, the temperature can be approximated to initially be around the initial temperature of 290 K due to negligible change in internal energy.

The student is asking about calculating the temperature at state 2 (T2) for air after it has been compressed in a compressor and then cooled at a constant pressure. The inputs given are initial pressure (100 kPa), initial temperature (290 K), final pressure (1 MPa), work input to the compressor (209 kJ/kg), and the heat removed from the air in the cooler (207 kJ/kg).

To find the temperature at state 2, we first note that the work done on the gas increases its internal energy, and then the cooling process at a constant pressure removes some of that energy. Using the first law of thermodynamics, which for a control volume can be expressed as Q-W=ΔU (where Q is the heat transfer, W is work done, and ΔU is the change in internal energy), we can set up the problem.

However, as per the problem statement details, the heat removed is almost equal to the work done, so we can assume that the temperature after cooling is close to the initial temperature, but this would not be practically valid if not for the fact that we are told to neglect changes in kinetic and potential energy. The exact final temperature would normally be determined using specific heat capacities and applying energy conservation, but the data provided implies there's not much change in internal energy (since Q ≈ W). Therefore, we can initially approximate the final temperature (T2) to be around 290 K, which could then be adjusted given more information about the properties of air (i.e., specific heats).

To precisely determine the accurate value of T2, the properties of air at specific conditions along with the specific heats at constant volume or pressure would be necessary to apply, which are not provided in the details given above.

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