1. Class : 가 Group : 4 Member : 김경홍, 김두용, 임채원, 이주호 임채원, 이주호

2. Contents  Introduction  Experiment’s environment and equation (COP)  Circuit  Step1 - 5  COP  Conclusion  Q&A

3. Introduction  Purpose : To optimize COP  How did we drive the machine? Step1 : All parts were drove fully. Step2 : Speed of condenser’s fan slowed down. Step3 : Speed of evaporator’s fan and condenser’s fan slowed down. Step4 : Turn the expansion valve to reduce the quantity of refrigerant Step5 : Only speed of evaporator’s fan slowed down.

4. Experiment’s environment and equation -5~+5 O CDeclination 0 O CStandard Temp. 100 min.Total Input Time 1 min.Data Input Time 28.8 %Laboratory(Hum.) 22.6 O CLaboratory(Temp.) 08. 04. 18Date  Condition

5. Experiment’s environment and equation  COP equation

6. Circuit

7. Step 1 : All parts were drove fully.  Work (↑)  Refrigeration effect (↓)

8. Step 1 : All parts were drove fully.  COP (↓)

9. Step 2 : Speed of condenser’s fan slowed down.  Compressor’s pressure (↑) -> Condenser’s driving time (↑)  Heat exchange per time (↑)  Cycle time (↑) Condenser Compressor

10. Step3 : Speed of evaporator’s fan and condenser’s fan slowed down.  Unstable temperature  The longest cycle time Compressor Condenser

11. Step3 : Speed of evaporator’s fan and condenser’s fan slowed down.  Evaporator’ Finite element analysis 0.5 m/s Fan speed 0.2 m/s Fan speed

12. Step4 : Turn the expansion valve to reduce the quantity of refrigerant  Compressor’s temperature and pressure (↑)  Evaporator entrance temperature (↑) Evaporator Compressor

13. Step5 : Only speed of evaporator’s fan slowed down.  Condenser enthalpy : High  High heat exchange : Fast and Big CondenserEvaporator Condenser

14. COP (coefficient of performance)  COP of step 2,3,4 was becoming slowly low.  Optimized experiment was step5.

15. Conclusion  Q H is decided by fan speed of condenser.  Q L is decided by fan speed of evaporator.  Turing expansion valve causes temperature of evaporator and compressor to rise.

16. Question and answer Q & A