替代HCFC22新型制冷剂爆炸极限的研究1

1、中国制冷学会中国制冷学会Chinese Association of Refrigeration Qi CHEN*, Guang-ming CHEN, Rui ZHANG Institute of Refrigeration and Cryogenics, Zhejiang University 25/08/2007, Beijing, China EXPERIMENTAL STUDY ON EXPLOSION LIMITS OF A NEW ALTERNATIVE REFRIGERANT TO HCFC-22中国制冷学会中国制冷学会Chinese Association of Refrige

2、ration25/08/2007BackgroundCFCs and HCFCsDepletion of the Ozone layer (ODP)Greenhouse effect (GWP)Alternative refrigerantsHCs: ammonia, propane, isobutane, ODP=0，GWP is low; safe, toxic problemHFCs: ODP=0, pure refrigerants R161中国制冷学会中国制冷学会Chinese Association of Refrigeration25/08/2007Other names: HF

3、C-161, R161, Ethyl fluorideRamification of ethane halogenation (乙烷的卤族元素衍生物)Formula: CH3-CH2FMolecular weight: 48.06 g/molCAS Registry Number: 353-36-6Tboil=-37.5 T Tc c= =375.31 K P Pc c= =5.02775 MPa c =293.05 kg m-3 Atmospheric Life: 0.3 YearODP ：0GWP ：10HCFC-22 (CHClF2 )ODP=0.034 , GWP=1700 Atmos

4、pheric Life: 11.9 YearsTboil= -40.81 Tc=369.3 KPc=4.990 MPa c =523.8 kg m-3vBasic Thermodynamic Property of Fluoroethane中国制冷学会中国制冷学会Chinese Association of Refrigeration25/08/2007nAlternative refrigerantsnHFC mixturesR410aR407cnZhejiang University has proposed a new ternary mixture of HFC-161/125/32

5、(mass%, 51:34:15, M1) as an alternative refrigerant to R22. The cycle performance, pvTx properties, fluid phase equilibrium of this new mixture have been studied in our group.中国制冷学会中国制冷学会Chinese Association of Refrigeration25/08/20071T138T271514T6T91112JTT43TTTJ510PPPPPTTTFig.1 Air-water heat pump e

6、quipment1 Compressor; 2 Four-way valve; 3 Indoor heat exchanger; 4 Accumulator; 5 J-T valve; 6 Outdoor heat exchanger; 7 Air duct; 8 Cold source heat exchanger; 9 Fan; 10 Electric heater;11 Water pump; 12 Flow meter; 13 Water tank; 14 Temperature transducer; 15 Pressure transducer; 中国制冷学会中国制冷学会Chine

7、se Association of Refrigeration25/08/2007-505101520251.01.52.02.53.0heating COPinlet air temperature ()inlet water temperature = 40HCFC-22M1R407C-505101520252.53.03.54.04.5cooling COPinlet air temperature ()inlet water temperature = 40HCFC-22M1R407CFig2. The COP of the new refrigerant is close to R2

8、2 and great than that of R407c中国制冷学会中国制冷学会Chinese Association of Refrigeration25/08/2007Fig3. pvTx experimental apparatus a sample cell, a high-accuracy thermostatic bath, a pressure measurement system, a temperature measurement system, and a vacuum system.中国制冷学会中国制冷学会Chinese Association of Refriger

9、ation25/08/20078911631312放 thermostated bath; 2. equilibrium cell; 3. multi-meter; 4. circulation pump; 5. gas chromatograph; 6. heater; 7. refrigeration system; 8. calibrated platinum resistance thermometer; 9. stirrer; 10. vacuum pump; 11. temperature control meter;12. pressure trans

10、fer; 13. differential pressure transmitter; 14. samples; 15. high-pressure nitrogen.Fig. 4 Schematic diagram of the VLE apparatus中国制冷学会中国制冷学会Chinese Association of Refrigeration25/08/2007Patent of the Alternative Refrigerant to R22Mass%HFC-161: 30-60 HFC-125: 25-50 HFC-32: 5-35中国制冷学会中国制冷学会Chinese As

11、sociation of Refrigeration25/08/2007nExperimental study on explosion limits of a new alternative refrigerant to HCFC-22nA new mixture of HFC-161, HFC-125 and HFC-32 is considered to be a promising alternative refrigerant to HCFC-22nReliable information about the flammability and the inertion by the

12、nonflammable component (HFC-125) is essential for its application as a working fluid in the refrigeration systemnTwo experimental apparatus (GB/T 12474-90 and ASTM 681-01 ) with high acccuracy were established to test the explosion limits of flammable refrigerants中国制冷学会中国制冷学会Chinese Association of R

13、efrigeration25/08/20071. Safety stopper; 2. Reaction tube;3. Inlet valve; 4. Vacuum pump; 5. Desiccation bottle;6. Voltage induction instrument;7. Electrode; 8. Pressure reducer valve;9. Stirrer; 10. Pressure gauge Fig.5 Explosion Limit Test Experimental Apparatus (GB/T 12474-90)中国制冷学会中国制冷学会Chinese

14、Association of Refrigeration25/08/2007Fig. 6 Tube vessel explosion phenomena中国制冷学会中国制冷学会Chinese Association of Refrigeration25/08/2007TW22TW4V3TW351气侧配U1U2V2TV1进空气34V1TW1验侧实室外T1T2678Sample cell Experimental vessel Fig.7 Explosion Limit Test Experimental Apparatus (ASTM 681-01)中国制冷学会中国制冷学会Chinese Ass

15、ociation of Refrigeration25/08/2007进 样 气93排 气 口521轻 质 弹 簧768高 压 电 源4连 接 真 空 泵 、 进 气 管 及 压 力 计101. Glass vessel; 2. Ignition electrode;3. Stirrer; 4. Platinum resistance thermometer; 5. Heat preservation box;6. Fan; 7. Heater; 8. WindowFig.8 Experimental Vessel中国制冷学会中国制冷学会Chinese Association of Refri

16、geration25/08/2007 The explosion vessel consists of a closed glass sphere with an internal volume of 12 dm3. The mixture is ignited with an induction spark drawn between electrodes located at the center of the sphere. The electrodes are 6.4 mm apart. The ignition arc is generated by a high-voltage t

17、ransformer 15 kV and is maintained for 0.5 s. The ignition energy released is approximately 5 J, which is sufficiently high to ignite a combustible mixture. All experiments were carried out at room temperature (23 1 ) and initial sample pressure of 101.325 kPa. Before each test the sphere was evacua

18、ted and purged with the gas mixture. For the measurements, components of the mixture were introduced successively to the vessel by the partial pressure method. The mixture was stirred for 10 min and then left for 1 min before ignition. During and after ignition, the pressure was measured with U-type

19、 manometers, and temperature with platinum resistance thermometers. The occurrence of ignition was also observed by the video camera.中国制冷学会中国制冷学会Chinese Association of Refrigeration25/08/2007Blaze is up Blaze is down Fig.9 Sphere vessel explosion phenomena中国制冷学会中国制冷学会Chinese Association of Refrigera

20、tion25/08/2007Table 3. The explosion limits of HFC-32 and HFC-161RefrigerantThe LEL and UEL values in the air (volume %)ExperimentLiterature (Dupont, 1996)HFC-3213.91-30.5014.0-31.0HFC-1613.60-18.033.8-18.0 For each gas, the explosion range deviations of the expermental data from the literature (Dup

21、ont, 1996) are within 0.5 %. The results of the experiment have a good reproducibility 中国制冷学会中国制冷学会Chinese Association of Refrigeration25/08/20070.000.050.100.150.200.250.300.350.400.450.50051015202530350.000.050.100.150.200.250.300.350.400.450.5005101520253035Mixture in the air (volume) %HFC-125/HF

22、C-32 (Volome) % LEL UEL0.00.51.01.52.02.53.03.505101520250.00.51.01.52.02.53.03.50510152025 LELMixture in the air (volume) %HFC-125/HFC-161 (volume) % UEL Fig. 10 The explosion limit of HFC-125/32Fig. 11 The explosion limit of HFC-125/161中国制冷学会中国制冷学会Chinese Association of Refrigeration25/08/20070.00.20.40.60.81.00.00.20.40.60.81.00.00.20.40.60.81.0Flammability zoneCritical Flammability LineHFC-125 (mass ratio)HFC-32 (mass ratio)Non-flammability zoneHFC-161 (mass ratio)0.00.20.40.60.81.00.00.20.4