“NUMERICAL AND EXPERIMENTAL

INVESTIGATION ON AN ADIBATIC CAPIILARRY

TUBE WITH ALTERNATIVE

REFRIGERANTS”

DEPARTMENT OF

MECHANICAL ENGINEERINGGOVT. COLLEGE OF

ENGINEERINGAMRAVATI 444 604

BY-SHREYAS V. LOKHANDEBHUSHAN G. PATIL

Study Of Refrigerants

Numerical Investigation On A

Capillary Tube

Experimental Setup

Experimental Investigation On A

Capillary Tube.

Conclusion

Scope Of The Project

PROJECT

AGENDA

Study Of RefrigerantsRefrigeran

tBoiling Point

(°C)Flammability ODP GWP

R12 -29.8 A1 0.82 10600

R22 -41.4 A1 0.034

1700

R32 -51.7 A1 0 550

R134a -26.1 A1 0 1300

R152 -24 A2 0 120

RE170 -24.8 A3 0 1

R600a -11.7 A3 0 20

R290 -42.2 A3 0 20

R125 -54.6 A1 0 3400

R404 -46.6 A1 0 3800

R407 -54.6 A1 0 3900

R410 -51.6 A1 0 1700

Study of refrigerants

Numerical Investigation

Fig. Variation of COP vs. evaporator temperature for refrigerant R22, R410, R134a, R152, R32 and R152+R134a

Fig. Variation of refrigerating effect vs. evaporating temperature for refrigerant R22, R410, R134a, R152a, R32 and Mixture R152+ 134a resp.

Fig. Variation of compressor work w.r.t. evaporating temperature for refrigerant R22, R410, R134a, R152a, R32 and Mixture R152+ 134a resp.

Fig. Variation of Pressure ratio w.r.t evaporating effect for refrigerant R22, R410, R134a, R152a, R32 and Mixture R152+ 134a respectively.

-15 -10 -5 0 5 10 150

2

4

6

8

10

12R22

R32

R152a

R134

R134a+R152 (50%/50%)

R134a+R152a (70%/30%)

R134+R152 (30%/70%)

evparator temperature ,ºC

CO

P

Refrigerant At -15ºC At -5ºC

R152a 3.193 3.164

R134a -2.614 -1.594

R32 -2.76 -3.031

R134a+R152 (50%/50%)

1.37 1.849

R134a+R152 (30%/70%)

2.756 3.199

R134a+R152 (70%/30%)

-1.134 -0.74

Comparison w.r.t.R22

Experimental Setup

Main Components1. Compressor :

2. Fan cooled condenser

3. Rotameter

4. Capillary Tube We have used 4 different types of capillary tubes

d= 0.055inch / 1.397mm , L=0.75m

d=0.064inch / 1.62mm , L=1m

d=0.070inch / 1.778mm , L=1m

d=0.090inch / 2.286mm , L=2m

5. Evaporator.

Other Components Refrigerant used: R22, R410, R134a Compressor oil for R22 and R410 - Mineral oil For R134a - POE oil Energy meters 12 Thermocouples 4 pressure gauges

Experimental Results

Fig: Variation of pressure ratio with capillary tube diameter

Fig: Variation of pressure drop with capillary tube diameter

Fig: Variation of mass flow rate with capillary tube diameter

Fig: Variation of refrigerating effect vs. capillary tube diameter

Figure 4.5: Variation of compressor work w.r.t. Capillary tube diameter

Figure 4.6: Comparison of COP vs. capillary tube diameter

Fig. Variation of Pressure ratio Fig. Variation of Compressor work

Fig.Variation of COP

Conclusion R152a refrigerant Is better replacement to R134a

refrigerant in refrigeration and air-conditioning systems

Mass flow rate is highest for R134a when 0.070” capillary is used

COP is approximately same for R134a and R22 on both capillary tubes

Pressure drop & Pressure ratio decreases as capillary diameter increases and is highest in case of R410

Experimental value of COP was less than numerical as losses were not considered in numerical investigation

The results of both experimental and computational are approximate

Hence the computational results are validated with experimental results

Scope of the project Currently the R22 is used as refrigerant

in the refrigeration systems which as 0.034 ODP and 10600 GWP, so it needs a replacement

R134 and 152a are alternative refrigerants in the refrigeration systems according to our theoretical investigation

Further study can bring out new refrigerants in this field which will serve boon to society

Also good capillary tube designs gives best results on alternative refrigerants

Referances1) B.O. Bolaji, M.A. Akintunde, and T.O. Falade2) Comparative Analysis of Performance of Three Ozone-Friends HFC Refrigerants in a Vapour

Compression Refrigerator3) Mahmoud Ghodbane 4) An Investigation of R152a and Hydrocarbon Refrigerants in Mobile Air Conditioning5) N. S. N. S .6) Estimation of Possibility of Usage of Quasiazeotropic Mixture R134a/R152a in Refrigerating

Engineering7) A.Baskaran, P.Koshy Mathews8) Thermal analysis of vapour compression refrigeration system with R152a and its blends R429A,

R430A, R431A and R435A9) Pressure drop of pure HFC Refrigerant and their mixture flowing in capillary tubes s.d chand10) Lorentzen G. Revival of carbon dioxide as a refrigerant. Int J Refrig 1994;17:292–300.11) Bansal PK, Rupasinghe AS. A homogeneous model for adiabatic capillary tubes. Appl Thermal Eng

1998;18:207–19.12) Gu B, Li Y, Wang Z, et al. Analysis on the adiabatic flow of R407C in capillary tube. Appl Thermal

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