stugger
17-11-2009, 05:09 PM
Your home work for the week is to study a p-h chart for refrigerant R404a, and draw out the cycle (assuming 100% isentropic efficiency for the compression cycle). Detail the entry and exit conditions for the compressor, condenser evaporator and expansion device.
Condition details to include:
<LI style="mso-list: l1 level1 lfo1" class=MsoNormal>Pressure. <LI style="mso-list: l1 level1 lfo1" class=MsoNormal>Temperature. <LI style="mso-list: l1 level1 lfo1" class=MsoNormal>Enthalpy. <LI style="mso-list: l1 level1 lfo1" class=MsoNormal>Entropy.
Fluid state.
Refrigeration Cycle:
<LI style="mso-list: l0 level1 lfo2" class=MsoNormal>Evaporating temperature, -30OC. <LI style="mso-list: l0 level1 lfo2" class=MsoNormal>Condensing temperature, +40OC. <LI style="mso-list: l0 level1 lfo2" class=MsoNormal>Evaporator useful superheat, 5K. <LI style="mso-list: l0 level1 lfo2" class=MsoNormal>Non-useful superheat, 20K. <LI style="mso-list: l0 level1 lfo2" class=MsoNormal>Condenser sub-cooling, 5K.
Additional liquid sub-cooling, 10K
Finally what is the refrigerant mass flow rate for the cycle 100, and what is isentropic efficiency?
Condition details to include:
<LI style="mso-list: l1 level1 lfo1" class=MsoNormal>Pressure. <LI style="mso-list: l1 level1 lfo1" class=MsoNormal>Temperature. <LI style="mso-list: l1 level1 lfo1" class=MsoNormal>Enthalpy. <LI style="mso-list: l1 level1 lfo1" class=MsoNormal>Entropy.
Fluid state.
Refrigeration Cycle:
<LI style="mso-list: l0 level1 lfo2" class=MsoNormal>Evaporating temperature, -30OC. <LI style="mso-list: l0 level1 lfo2" class=MsoNormal>Condensing temperature, +40OC. <LI style="mso-list: l0 level1 lfo2" class=MsoNormal>Evaporator useful superheat, 5K. <LI style="mso-list: l0 level1 lfo2" class=MsoNormal>Non-useful superheat, 20K. <LI style="mso-list: l0 level1 lfo2" class=MsoNormal>Condenser sub-cooling, 5K.
Additional liquid sub-cooling, 10K
Finally what is the refrigerant mass flow rate for the cycle 100, and what is isentropic efficiency?