COMPARATIVE STUDY OF NEW ECOLOGICAL GASES

Transcription

1 2017 COMPARATIVE STUDY OF NEW ECOLOGICAL GASES JOSE LUIS URIBE-ECHEBARRIA JAVIER MARTINEZ DE ILARDUYA ANARTZ ITURRIOTZ LEIRE LONBIDE INTXAUSTI FRINSA S.L.

2 1. INTRODUCTION The purpose of the study is to provide a tool for both installers and maintainers, as designers and distributors of refrigerant gases, to be able to choose the most appropriate refrigerant to their needs, due to the large number of new gases that have appeared in the market. It should be mentioned that this work has been done within the TKgune program of the Basque Government. TKgune is a Network of Innovation, Technology Transfer and Competitive Enterprise development for the implementation and improvement of technology, developing a specialized offer, including advanced training and technical value - added services in the field of R + D + I, for the development of innovation dynamics and continuous improvement of the key processes and products of SMEs, to help them access to emerging markets and high added value. In TKgune Vocational Training centres in collaboration with the Basque Government are involved. TKgune is divided into five strategic environments, which include the following technology areas: Automation, Energy, Automotive, Manufacturing and Creative Industries. Through the network of centres and faculty of Vocational Training in the ENERGY environment in which the Integrated Centre of Vocational Training of Construction and Energy Efficiency of Vitoria-Gasteiz, Eraiken CIFP Construcción LHII., we offer the possibility of assistance in the implementation and / or improvement of new work processes. The company will thus have personalized tutoring of our professionals, such as the possibility of using our network of centres as a test bench, prior to the implementation of the production process. On the initiative of the FRINSA SL company, the ERAIKEN centre has carried out this project, which consists of analysing how the new refrigerant gases, including the new organic refrigerants, to replace those currently used in traditional Air conditioning, conservation and freezing. As we know, we cannot talk about an ideal gas that fits in all kinds of installations. Therefore, it is necessary to study each case, the conditions of application, considering that we should achieve maximum energy efficiency, 1

3 complying with environmental regulations, without harming the performance of the facility and being economically viable. This scenario forces planners and installers, above all, not to mention conservative-repairers, to take into consideration a new generation of refrigerant gases or refrigerators that are not yet sufficiently tested. Because of this new scenario, a study has been carried out to clarify the characteristics and consequences of using these new refrigerants in both new installations and installations that are in operation. The study has consisted in checking both the behaviour and the characteristics determined by the manufacturers of new refrigerants, considering that some refrigerants are in force until To this end, two refrigeration chambers of identical construction characteristics were installed and both were in identical environmental conditions and their properties and characteristics were verified. 2

4 2. CHARACTERISTICS OF THE INSTALLATION 1. Illustration. REFRIGERATOR SCHEME 3

5 2. Illustration. REFRIGERATOR HOUSING PLANT 4

6 3. Illustration. SITE OF THE COMMERCIAL REFRIGERATOR 4. Illustration. INSTALLATION AND EQUIPMENTS 6. Illustration. INSTALLATION DATA SHEET 5. Illustration. CHECKING AND ADJUSTING THE INSTALLATION 5

7 The refrigerant gases checked in this project have been tested in medium (-5 / 0 C) and low temperature (-25 / -20 C) and there have been as follows: OPERATING TEMPERATURE MEDIUM TEMPERATURE MEDIUM TEMPERATURE LOW TEMPERATURE REFERENCE REFRIGERANT R 404 A R 134 A R 404 A ALTERNATIVE REFRIGERANT R 407 F R 438 A R 442 A R 434 A R 422 D R 450 A R 1234 YF R 1234 ZE R 513 A R 434 A R 422 D R 449 A R 448 A R 442 A R 453 A R 434 A R 452 A 1. Table. TESTED REFRIGERANTS 6

8 The following table shows the data corresponding to the refrigerants used for the study. In the data table enclosed, you can see the values corresponding to refrigerant charges, GWP, prices, taxes of each refrigerant..., which will allow us to select the proper refrigerant in each of the situations. REFRIGERANTS ODP GWP PHYSICAL/ENVIRONMENTAL PROPERTIES Price /kg Tax/kg Glide (ºC) Gas charge (Kgs) TEWI (Kgs CO2) R134A , , ,961 R450A ,11 10,94 0,79 1, ,011 R1234ze , , ,629 R1234yf , ,869 R422D ,79 52,46 4,5 1, ,847 (M Tª) ,01 62,62 1,5 1, ,535 R513A ,8 11,44 0 1, ,265 R404A (M Tª) ,69 75,68 0,7 1, ,729 R407F ,61 34,1 6,4 1, ,666 R438A ,5 43,03 4 1, ,964 (M Tª) ,94 35,86 4,6 1, ,577 R404A (L Tª) ,69 75,68 0,7 1, ,9 (L Tª) ,94 35,86 4,6 1, ,033 R448A , , ,583 R449A ,25 26,15 6 1, ,79 (L Tª) ,01 62,62 1,5 1, ,84 R452A ,90 41,34 3 1, ,583 R453A ,835 33,28 4,2 1, , Table. CHARACTERISTICS OF THE REFRIGERANTS. GWP: AR3 IPCC VERSION III NOTE: all data about prices and tax are referred to the Spanish market. 7

9 ENERGY CONSUMPTION Kwh/day ,91 20,53 20,70 21, ,86 12,15 11,42 12,31 12,27 14,02 13,47 15,08 15,58 14,58 13,88 14,24 13,23 13, Illustration. DAILY ENERGY CONSUMPTION (KWh/day) 3. METODOLOGY The test methodology consisted in verifying the behaviour of the installation in identical operating conditions (same thermal load and varying the refrigerant gases. 8

10 DATA ACHIEVED Suction Temperature Discharge Temperature High Side Refrigerant Out Temperature Ambient Temperature Cool room Temperature Discharge Pressure Suction Pressure Compressor consumption Energy consumption Leaks and glide testing Refrigerant measured charge by weight MESURING DEVICES T, P probes Data logger: CLIMACHECK Energy counter: CIRCUTOR MOD. AR 6 Data logger: AKM (Danfoss) CONCLUSIONS The output of this study is to describe in detail the function of different refrigerants by determining their advantages and disadvantages. COP. Cooling Capacity. Discharge Temperature. Glide tests. Expansion valve adjustments in comparison to R-404A and R134A. Real refrigerant charge (kg). Electric consumption (kwh). TEWI. 9

11 4. PROCESS TO BE FOLLOWED PHASES DESCRIPTION COMMENTS Prepare fridge freezers and installation Charge the refrigerant gas Process to be carried out until stabilization Defrost process Cause leaks Make installation inert Prove out the pressure at 28 bar Make vacuum in the installation until 760 mmhg Weigh the refrigerant gas Charge the refrigerant (in liquid phase) through the suction valve by means of a pressure gauge Start (ON/OFF) both of the fridge freezers simultaneously from vacuum condition until stable condition If necessary, recharge the refrigerant gas Load up to full viewfinder Check and write down data Defrost with electrical resistance Check and take data The installation should be kept on balance until leaks are provoked The induced leaks would be done as Follow the procedure until the installation stabilizes After 3 hours Carry out the procedure every 3-4 hours Keep the procedure this way and under this condition for 1 day Each leak procedure 10

12 percentage of weight (20%) means 3 hours Recharge refrigerant gas Cause leaks Fill the installation by weight (20%). Recharge the gas and start up the system until it stabilizes. Then observe the performance of the system Provoke again a 20% leak Fill the installation by weight (20%). Recharge the gas and start up the system until it stabilizes (until reaching Evap. T). Then observe the performance of the system Recharge with the same weight extracted Follow the same procedure until the system does not work Record the grams of gas recharged Keep functioning during 30 minutes Keep functioning during 3 hours CONCLUSION Refrigerant variation Do not consider the leaks Restart the procedure Make the installation inert blowing nitrogen Make vacuum in the installation Adjust the fridge freezers to initial condition Clean the system Fill the installation with a new oil before starting again e 3. Table. DEVELOPMENT OF THE PROCESS 11

13 5. CONCLUSIONS 1. DATA AND OUTPUTS OF THE REFRIGERANTS TESTED IN THE FIRST ROOM IN MEDIUM TEMPERATURE In the data table enclosed, you can see, among others, the values corresponding to Refrigeration Capacities, COP, Tª of discharge of each of the refrigerants, that will help to select the most appropriate option in each one of the installations. On the other hand, and about the part of the test corresponding to the study of the possible variations in the properties of the refrigerants that are mixtures, when carrying out successive leaks, in these behaviours have not been detected very significant changes. The following diagram shows the properties of the different gases checked in 1 st room. The fluorinated gases that have been tested in this room are R 134 A and its substitutes. R434 A Avg.T (ºC) = 1,56 Suction Dens. (Kg/m3) = 16,50 Net Refrig Cap. (Kw) =2,62 Valv.Open. (%) = 63,13 Charge (gr) = 1520 Liq. Dens.25ºC 1096 Kg/m3 R422 D Avg.T (ºC) = 1,06 Suction Dens. (Kg/m3) = 15,40 Net Refrig Cap. (Kw) =2,25 Valv.Open. (%) = 60,24 Charge (gr) = 1300 Liq. Dens.25ºC 1150 Kg/m3 R450 A Avg T (ºC) = 0,74 Suction Dens. (Kg/m3) = 7,50 Net Refrig Cap. (Kw) = 1,72 Valv.Open. (%) = 41,81 Charge (gr) = 1730 Liq. Dens.25ºC 1175,1 Kg/m3 R134 A Avg.T (ºC) = 0,55 Suction Dens. (Kg/m3) = 9,44 Net Refrig Cap. (Kw) = 2,06 Valv.Open. (%) = 36,53 Charge (gr) = 1300 Liq. Dens.25ºC 1206 Kg/m3 R1234 yf Avg. T (ºC) = 0.85 Suction Dens. (Kg/m3) = 12,50 Net Refrig Cap. (Kw) =1.91 Valv.Open. (%) = Charge (gr) = 1000 Liq. Dens.25ºC 1092 Kg/m3 R513 A Avg. T (ºC) = 1,14 Suction Dens. (Kg/m3) = 11,10 Net Refrig Cap. (Kw) = 2,49 Valv.Open. (%) = Charge (gr) = 1010 Liq. Dens.25ºC 1185,5 Kg/m3 R1234 ze Avg. T (ºC) = 3.62 Suction Dens. (Kg/m3) = 7,50 Net Refrig Cap. (Kw) = 1,75 Valv.Open. (%) = Charge (gr) = 890 Liq. Dens.25ºC 1293 Kg/m3 1. Illustration. REFRIGERANTS PROPERTIES, 1 ST ROOM 12

14 In the following table, there are characteristics of refrigerants for this first group in comparison to the reference of this group which is the R134 A. Room T (ºC) LP(Bar) Ev T (ºC) C O M P A R A T I V E R134A Medium Temperature Heat addition 1000w M T Suction T (ºC) Superheat (ºC) HP (Bar) Conden. T (ºC) EntEV T (ºC) Sub-cool(ºC) Discharge T (ºC) Isoent Perform Elec. Power (Kw) COP Cool. Cap (Kw) Cool. Cap (%) Comp. Ratio Exp V. (%) Suc. Dens. (Kg/m3) R134A R450A R1234ze R1234yf R513A R422D 0,55 0,74 3,62 0,85 1,14 1,06 1,56 0,84 0,71 0,53 1,06 1,11 2,03 2,05-12,05-10,43-8,87-11,89-11,33-14,06-13,99 4,73 4,75 7,32 3,54 4,77 2,85 1,43 16,78 14,96 16,19 15,44 16,05 15,62 14,04 8,32 7,79 6,89 8,03 8,51 14,64 13,75 36,85 39,43 41,15 35,36 35,53 38,98 36,82 35,20 37,61 38,04 34,25 32,93 37,09 31,82 1,66 1,50 3,11 1,10 2,60 0,66 3,60 67,30 66,52 63,11 57,56 57,08 66,13 60,18 71,48 65,24 70,21 63,10 77,37 65,98 69,44 0,67 0,63 0,59 0,70 0,72 0,98 0,98 3,06 2,72 2,98 2,72 3,48 2,29 2,67 2,06 1,72 1,75 1,91 2,49 2,25 2, ,50 84,95 92,72 120,87 109,22 127,18 5,07 5,14 5,16 4,38 4,51 5,16 4,84 36,53 41,81 39,98 65,10 50,69 60,24 63,13 9,44 7,50 7,50 12,50 11,10 15,40 16,50 Liq. Dens at 25ºC (Kg/m3) 1206, , , , , ,00 Refr.Charge (Kg) 1,30 1,73 0,89 1,00 1,01 1,30 1,52 Reference value Lower value Higher value 4. Table. REFRIGERANTS CHARACTERÍSTICS, 1 ST ROOM 13

15 The following graphs show the behaviour of an operating cycle of the gases tested in 1 st room. In the "drop in" operation that has been used in this test, we observe the order, from highest to lowest, of refrigerants that more easily exceed the thermal load of the heater (1000 W) and in addition to the other loads (transmission for refrigeration panels, defrosting, evaporator fans...). For R1234ze, to operate the expansion valve satisfactorily, an alternative orifice has been chosen and in addition to it the superheat has been modified R134A R450A R1234yf R513A R422D R1234ze 5 R1234ze with regulation Illustration. REFRIGERANTS BEHAVIOUR, 1 ST ROOM 14

16 The following graphs correspond to the results obtained of the gases tested in 1 st room. The test conditions that have been established for these gases are the next ones: O Test conditions: Heater thermal load: 1000w Heating cycle: 50 (ON)-10 (OFF) Ambient Temperature: 25-27ºC HIGH AND LOW PRESSURE FOR R134A AND ALTERNATIVE GASES 15,00 1 5,00 2,03 2,05 0,84 0,71 0,53 1,06 1,11 LP(Bar) 14,64 13,75 8,32 7,79 8,03 8,51 6,89 HP(Bar) R134A R450A R1234ze R1234yf R422D R513A COOLING CAPACITY (KW) FOR R134 A AND ALTERNATIVE GASES ,50 84,95 92,72 109,22 127,18 120,87 Cap Frig(%) R134A R450A R1234ze R1234yf R422D R513A EXP. VALVE OPENING (%) FOR R134A AND ALTERNATIVE GASES R134A ,53 41,81 39,98 55,00 V.Exp % 60,24 63,13 50,69 R450A R1234ze R1234yf R422D R513A 15

17 CONDENSING AND DISCHARGE TEMPERATURE FOR R134A AND ALTERNATIVE GASES ,43 38,98 41,15 36,85 35,36 36,82 TªCond(ºC) 35,53 67,30 66,5263,11 66,13 57,56 Tª Desc.(ºC) 60,18 57,08 R134A R450A R1234ze R1234yf R422D R513A ELECTRIC POWER (KW) FOR R134A AND ITS ALTERNATIVE GASES 0,98 0,98 1,00 0,80 0,67 0,63 0,59 0,70 0,72 R134A R450A R1234ze 0,60 0,40 0,20 R1234yf R422D R513A P.Elec COP FOR R134 A AND ALTERNATIVE GASES 3,50 3,00 2,50 2,00 1,50 1,00 0,50 3,06 2,72 2,98 COP 2,72 2,29 2,67 3,48 R134A R450A R1234ze R422D R513A R513A 3. Illustration REFRIGERANTS PROPERTIES IN MEDIUM TEMPERATURE, 1 ST ROOM 16

18 2. DATA AND OUTPUTS OF THE REFRIGERANTS TESTED IN THE SECOND CAMERA IN MEDIUM TEMPERATURE The following diagram shows the properties of the different gases checked in 2 nd room. The gases that have been tested in this room are R 404A and its alternative gases. R422 D Avg.T (ºC) = 4,2 Suction Dens. (Kg/m3) = 23,10 Net Refrig Cap. (Kw) = 2,76 Valv.Open. (%) = 67,12 Charge (gr) = 1520 Liq. Dens.25ºC 1095 Kg/m3 R407 F Avg.T (ºC) = 1,47 Suction Dens. (Kg/m3) = 12,00 Net Refrig Cap. (Kw) =3,12 Valv.Open. (%) = 41,40 Charge (gr) = 1200 Liq. Dens.25ºC 1117 Kg/m3 R404 A Avg.T (ºC) = 1,06 Suction Dens. (Kg/m3) = 18,20 Net Refrig Cap. (Kw) = 2,63 Valv.Open. (%) = 68,30 Charge (gr) = 1500 R438 A Avg.T (ºC) = 4,74 Suction Dens. (Kg/m3) = 12,50 Net Refrig Cap. (Kw) = 2,82 Valv.Open. (%) = 52,67 Charge (gr) = 1210 Liq. Dens.25ºC 1140 Kg/m3 R434 A Avg.T (ºC) = 2,24 Suction Dens. (Kg/m3) = 16,80 Net Refrig Cap. (Kw) =3,24 Valv.Open. (%) = 75,5 Charge (gr) = 1300 Liq. Dens.25ºC 1080 Kg/m3 Liq. Dens.25ºC 1048 Kg/m3 R442 A Avg.T (ºC) = 1,75 Suction Dens. (Kg/m3) = 1 Net Refrig Cap. (Kw) = 3.33 Valv.Open. (%) = 43,28 Charge (gr) = 1200 Liq. Dens.25ºC 1108 Kg/m3 11. Illustration. THERMODYNAMIC PROPERTIES OF THE GASES, 2 ND ROOM 17

19 The characteristics corresponding to this second group of refrigerants appeared in comparison to the reference that is the R404 A in the following table. C O M P A R A T I V E R 404A Medium Temperature Heat addition 2000w M T R404A R407F R438A R422D Room T (ºC) 1,06 1,47 4,74 1,75 4,2 2,24 LP(Bar) 2,53 2,14 2,03 2,23 2,14 2,46 Ev T (ºC) -15,73-15,99-12,54-15, Suction T (ºC) -1,13 3,19 5,75 3,55 2,08-4,85 Superheat (ºC) 14,38 17,01 16,46 16,82 15,98 9,01 HP (Bar) 15,00 15,26 13,98 15,43 13,08 14,46 Conden. T (ºC) 34,71 35,58 38,13 35,70 34,6 36,72 EntEV T (ºC) 33,76 33,10 36,07 32,80 32,6 33,81 Sub-cool(ºC) 0,78 0,19 0,49 1,11 0,97 Discharge T (ºC) 64,64 77,32 70,76 74,53 59,34 56,75 Isoent Perform 64,99 77,68 73,96 80,25 77,98 79,23 Elec. Power (Kw) 1,10 1,07 1,00 1,10 0,96 1,06 COP 2,40 2,90 2,82 3,02 2,89 2,94 Cool. Cap (Kw) 2,63 3,12 2,82 3,33 2,76 3,24 Cool. Cap (%) ,63 107,22 126,62 104,9 123,2 Comp. Ratio 4,53 5,18 4,94 5,09 4,48 4,47 Exp V. (%) 68,30 41,40 52,67 43,28 67,12 75,5 Suc. Dens. (Kg/m3) 18,20 12,00 12, ,1 16,8 Liq. Dens at 25ºC (Kg/m3) 1048, , , Refr.Charge (Kg) 1,50 1,20 1,21 1,20 1,52 1,3 Reference value Lower value Higher value 18

20 The following graph show the behaviour of an operating cycle (ON-OFF thermal load) of the refrigerant gases tested in 2 nd room. For, R422D and to operate the expansion valve satisfactorily, an alternative orifice has been chosen and in addition to it the superheat has been modified. 5 R404 A WITH REGULATION R422D WITH REGULATION WITH REGULATION Illustration. REFRIGERANTS BEHAVIOUR, 2 ND ROOM 19

21 The following graphs show the results about characteristics of the refrigerant gases tested in room 2. The test conditions that have been established for these gases are the following: Test conditions: Heater thermal load: 2000w Heating cycle: 50 (ON)-10 (OFF) Ambient Temperature: 25-27ºC 2 15,00 1 5,00 HIGH AND LOW PRESSURE FOR R404A ND ALTERNATIVE GASES 2,53 2,14 2,03 2,23 LP(Bar) 2,14 2,46 15,0015,26 15,43 13,98 14,46 13,08 HP(Bar) R404A R407F R438A R422D COOLING CAPACITY (KW) FOR R404 A AND ALTERNATIVE GASES ,63 107,22 Cap Frig(%) 126,62 104,90 123,20 R404A R407F R438A R422D OPENING VALVE (%) FOR R404 A AND ALTERNATIVE GASES ,30 41,40 52,67 V.Exp % 43,28 67,12 75,50 R404A R407F R438A R422D 20

22 CONDENSING AND DISCHARGE TEMPERATURE FOR R404A AND ALTERNATIVE GASES ,7135,58 38,13 35,70 34,60 36,72 77,32 64,64 70,76 74,53 59,34 56,75 R404A R407F R438A R422D TªCond(ºC) TªDesc. (ºC) ELECTRIC POWER (KW) FOR R404A AND ALTERNATIVE GASES 1,10 1,07 1,10 1,10 1,05 1,00 0,95 1,00 0,96 1,06 R404A R407F R438A R422D 0,90 0,85 P.Elec COP FOR R 404A AND ALTERNATIVE GASES 3,50 3,00 2,50 2,40 2,90 2,82 3,02 2,89 2,94 R404A R407F R438A 2,00 1,50 1,00 0,50 R422D COP 13. Illustration. REFRIGERANTS PROPERTIES IN MEDIUM TEMPERATURE, 2 ND ROOM 21

23 3. DATA AND OUTPUTS OF THE REFRIGERANTS TESTED IN THE FIRST AND SECOND ROOM IN LOW TEMPERATURE The next graph shows the physical properties of the gases tested in both chambers at low temperature. The fluorinated gases observed have been R404 A and its alternative gases for low temperature. R453 A Avg.T (ºC) = -18,90 Suction Dens. (Kg/m3) = 7,14 Valv.Open. (%) = 26,32 Charge (gr) = 1130 Liq. Dens.25ºC 1136 Kg/m3 R452 A Avg.T (ºC) = -19,69 Suction Dens. (Kg/m3) = 9,09 Valv.Open. (%) = 25,62 Charge (gr) = 1120 Liq. Dens.25ºC 1148,8 Kg/m3 R449 A Avg.T (ºC) = -18,66 Suction Dens. (Kg/m3) = 5,00 Valv.Open. (%) = 16,45 Charge (gr) = 1020 Liq. Dens.25ºC 1139 Kg/m3 R404 A Avg.T (ºC) = -19,38 Suction Dens. (Kg/m3) = 8,33 Apert.Válv. (%) = 23,61 Charge (gr) = 1500 Liq. Dens.25ºC 1048 Kg/m3 R442 A Avg.T (ºC) = -19,00 Suction Dens. (Kg/m3) = 6,25 Valv.Open. (%) = 16,42 Charge (gr) = 1200 Liq. Dens.25ºC 1096 Kg/m3 R448 A Avg.T (ºC) = -18,24 Suction Dens. (Kg/m3) = 4,50 Valv.Open. (%) = 16,38 Charge (gr) = 1250 Liq. Dens.25ºC Kg/m3 R434 A Avg.T (ºC) = -19,30 Suction Dens. (Kg/m3) = 7,70 Valv.Open. (%) = 28,22 Charge (gr) = 1520 Liq. Dens.25ºC 1108 Kg/m3 14. Illustration. THERMODYNAMIC PROPERTIES OF THE GASES AT LOW TEMPERATURE 22

24 Experimental Comparison of Low Temperature Refrigerants. R404A vs alternative refrigerants. C O M P A R A T I V E R404A Low Temperature Heat Addition 500w L.T. R404A R448A R449A R452A R453A Room T (ºC) -19,38-19,30-19,00-18,24-18,66-19,69-18,90 LP(Bar) 0,97 0,76 0,62 0,58 0,50 0,69 0,79 Ev T (ºC) -30,80-30,97-32,08-31,91-33,31-33,20-24,55 Suction T (ºC) -4,40-7,32-5,52-1,74-2,24-5,66-20,21 Superheat (ºC) 26,15 22,79 24,26 28,51 29,47 28,03 2,05 HP (Bar) 13,97 12,67 13,80 13,94 12,37 12,49 11,35 Conden. T (ºC) 32,07 30,58 31,70 33,16 29,38 32,77 31,48 EntEV T (ºC) 29,84 28,86 28,78 27,31 25,02 26,67 28,03 Sub-cool(ºC) 2,04 0,99 0,44 3,38-0,27-0,59 0,61 Discharge T (ºC) 67,68 59,71 66,64 63,13 60,84 57,87 56,35 Isoent Perform 82,00 83,70 8 Elec. Power (Kw) 0,83 0,72 0,74 0,69 0,66 0,71 0,77 COP 2,23 2,30 2,66 Cool. Cap (Kw) 1,85 1,66 2,05 Cool. Cap (%) 10 89,73 110,81 Comp. Ratio 7,60 7,77 9,14 9,46 8,91 7,98 6,90 Exp V. (%) 23,61 28,22 16,42 16,38 16,45 25,62 26,32 Suc. Dens. (Kg/m3) 8,33 7,70 6,25 4,50 5,00 9,09 7,14 Liq. Dens at 25ºC (Kg/m3) 1048, , , , , , ,00 Refr.Charge (Kg) 1,50 1,52 1,20 1,25 1,02 1,12 1,13 Reference value Lower value Higher value 23

25 The following graphs show the performance of a normal operating cycle (thermal load heater ON-OFF) of refrigerant gases tested in both rooms at low temperature (Tª - 20 ºC). -15 R449A WITH REGULATION R448A WITH REGULATION R448A Operation behaviour of the tested gases that reach a temperature of -25ºC in a cycle with orifice adjustment and regulation in the expansion valve R404A Tª Set -25ºC R452A Tª Set -25ºC Tª set -25ºC R453A Tª Set -25ºC 15. Illustration. THE BEHAVIOUR OF THE REFRIGERANTS AT LOW TEMPERATURE 24

26 The following graphs correspond to the results obtained from the refrigerants tested in the two rooms under low temperature conditions. The test conditions established for these gases are the following: Test conditions: Heater thermal load: 500w Heating cycle: 50 (ON)-10 (OFF) Ambient Temperature: 25-27ºC 15,00 1 5,00 HIGH AND LOW PRESSURE FOR R404A AND ALTERNATIVE GASES 0,97 0,76 0,62 0,58 0,50 0,79 0,69 LP(Bar) 13,97 12,67 13,8013,94 12,37 11,35 12,49 HP(Bar) R404A R448A R449A R453A R452A CONDENSING AND DICHARGE TEMPERATURE FOR R404A AND ALTERNATIVE GASES R404A ,0730,5831,7033,1629,3831,4832,77 TªCond(ºC) 67,68 66,64 59,71 63,1360,84 56,3557,87 Tª Desc.(ºC) R448A R449A R453A R452A EXP.VALV.OPENING (%) FOR R404A AND ALTERNATIVE GASES 3 25, ,00 1 5,00 23,61 28,22 16,42 16,38 16,45 V.Exp % 26,32 25,62 R404A R448A R449A R453A R452A 25

27 ELECTRIC POWER FOR R404A AND ALTERTENATIVE GASES AT LOW TEMPERATURE 1,00 0,83 0,72 0,74 0,69 0,66 0,77 0,71 R404A 0,50 R448A R449A P.Elec R453A R452A 2,70 2,60 2,50 2,40 2,30 2,20 2,10 2,00 COP FOR R404A AND ALTERNATIVE GASES AT LOW TEMPERATURE 2,23 2,30 COP 2,66 R404A R448A R449A R453A COOLING CAPACITY FOR R404A AND ALTERNATIVE GASES AT LOW TEMPERATURE ,73 110,81 R404A R448A R449A R453A R452A Cap Frig(%) 16. Illustration. REFRIGERANTS PROPERTIES IN LOW TEMPERATURE NOTE: The last two graphs, do not show values of all refrigerants since some values are out of range. 26

28 6. SUMMARY Summarizing, the most extraordinary notes that have been observed after conducting the study are: Cycle graphs have been performed in a general way for all the gases in each group, varying only the programming of the specific parameters of each one, without varying orifice nor values of superheating. In cases where adjustments have been made, it is indicated in the title of the graph. These cycle graphs show the capacity of the installation to overcome the thermal charge in each case. The tables that are attached, which indicate the values reached by each of the refrigerants tested, provide us with useful information to make a preliminary and approximate estimate of the performance of the installation. Specifically connecting the flow of refrigerant, specific refrigeration production and / or valve opening. As another complement for aiding the installer, when choosing between a refrigerant or another, in addition to the cooling performance, the one referring to the prices and taxes of each of them is attached, to provide another Criteria, in this case economic and environmental. The successive leaks and refills of refrigerant did not imply relevant changes of operation in the different tests carried out In relation to the configuration of the expansion system, the parameters of other refrigerants (R22, R407A) have been tested in some of the tests to check if there are any more stable improvements or operations, not producing this improvement in any of the cases. Medium Temperature: Generally, no special settings of the expansion system have been needed once the electronic control for each type of refrigerant has been configured. 27

29 Low Temperature: In this case, a specific adjustment of the expansion system in terms of orifice size and superheat values, in relation to the configuration of the reference refrigerant, is required in all the alternative gases. To carry out any retrofit, at least should be adjusted the elements (expansion valve...) and in the most adverse cases, some of the elements of the installation must be changed. In Low Temperature, under the conditions established, not all the gases tested reach -25ºC. Likewise, there have been situations with very low superheat. With the R453A the superheat was very low, even with risk of liquid entering the suction of the compressor. In this case, the size of the orifice (smaller) and the superheat (greater) were established, eliminating the problem described above and achieving a correct operation. Although with the R452 A. the situation was the opposite one. Another test carried out in Low Temperature was the change of the values called Ctes. Of Antoine, which are different and unique for each gas and adjusting them with them the electronic control of expansion valve can operate according to the specific characteristics of each refrigerant. For further information and / or doubts or any other question send an to the following address: JOSE LUIS URIBE-ECHEBARRIA: frinsasl@frinsasl.com LEIRE LONBIDE: llonbide@eraiken.com 28