Experimental Study Combining Electric Powered Compressor in
Automobile Air Conditioning System
Haolia Rahman
1 a
, Dianta Mustofa Kamal
1 b
, Yuli Mafendro Dedet Eka Saputra
1
,
Cecep Slamet Abadi
1
and Fathurrohman
2
1
Graduate school of Engineering, Politeknik Negeri Jakarta, Jl. Prof. DR. G.A. Siwabessy,
Kampus Universitas Indonesia, Depok, 16425, Indonesia
2
Mechanical Engineering Department, Politeknik Negeri Jakarta, Jl. Prof. DR. G.A. Siwabessy, Kampus Universitas
Indonesia, Depok, 16425, Indonesia
{haolia.rahman, dianta.mustofakamal, yulimafendro, cecep.slametabadi}mesin.pnj.ac.id
Keywords: Electricity-Driven Compressor, Electric Vehicle, Automobile Air Conditioning.
Abstract: Converting automobile air conditioning systems from internal combustion engine-based to electric-based
vehicles is challenging due to different power sources and limited parts available in the market. The present
study aimed to evaluate the performance of an electricity-driven compressor integrated into an automobile air
conditioning system. This preliminary test was conducted experimentally on a lab scale testbed and has not
been implemented in an actual automobile cabin. The ½ horsepower capacity of the electric compressor was
used in the system along with the instrument to measure the system's performance (i.e., COP). The fan speed
in the evaporator is variated to identify their impact on the system's performance.
1 INTRODUCTION
Due to the popularity of electric vehicles recently and
global attention to environmentally friendly energy
sources, converting internal combustion engine-
based vehicles (ICEVs) to electric-based vehicles
(EVs) is a promising option apart from manufacturing
new electric vehicles. A successful story of
converting ICEVs to EVs has been reported by
several researchers (Pedrosa, 2014), (Kaleg, 2015),
(Silva, 2019). However, previous studies of
converting ICEVs to EVs have not dealt with the
heating, ventilation, and air conditioning (HVAC)
system. Whereas the HVAC system is one of the
components that significantly underwent this change
in this conversion process.
The compressor is the main component used in
most automobile air conditioning (AAC) systems,
and it takes the most significant percentage of total
power consumption in AAC systems (i.e., 50-80%)
(Westphalen, 2001). In the case of ICEVs
compressors, the prime mover is coupled with the
a
https://orcid.org/0000-0002-3414-7225
b
https://orcid.org/0000-0001-9336-8936
engine, which must turn on whenever the HVAC
system is operated. The compressor speeds also
depend on the engine speed, which may mismatch
with cooling capacity demands. On the contrary, the
compressor used in the HVAC system for EVs is
independent due to an electricity-driven compressor
(Zhang, 2018), so energy consumption can be
managed efficiently.
Several concepts and strategies have been
proposed and tested to produce more energy efficient
in term of compressor in AAC system. Aurich (2018)
has tested four different compressor: scroll
compressor, rotary piston compressor, and double-
rotary piston. The study summarize that scroll
compressor has an overall very good performance
with a good coefficient of performance as well as low
pressure pulsation followed the rotary piston
compressor, The double-rotary piston compressor,
and the axial piston compressor. Baumgart (2015) has
been suggested a new powertrain concept of
compressor which equipped with electric motor dan
mechanical coupling to the gearbox and the main
motor. From the viewpoint of refrigerant, a low-
Rahman, H., Kamal, D., Saputra, Y., Abadi, C. and Fathurrohman, .
Experimental Study Combining Electric Powered Compressor in Automobile Air Conditioning System.
DOI: 10.5220/0011741500003575
In Proceedings of the 5th International Conference on Applied Science and Technology on Engineering Science (iCAST-ES 2022), pages 219-222
ISBN: 978-989-758-619-4; ISSN: 2975-8246
Copyright © 2023 by SCITEPRESS – Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)
219
Global Warming Potential refrigerants (i.e. R134a)
has been tested in accordance with the compressor of
AAC and it is proven to have better performance in
saving the energy consumed compare to conventional
one (Essa, 2021), (Wu, 2020). Lee (2013) found that
cooling capacity increased with the increase of the
compressor frequency in electric bus.
The performance of air conditioning using various
refrigerants has been tabulated by several studies in a
few last decades; among them is Kiatsiriroat (1997),
who revealed that R22 has COP between 2.5 to 4.8.
In this study, an electricity-driven compressor is
combined in conjunction with another part of vapor
pressure HVAC system in conventional ICE-based
vehicles. The tests were carried out experimentally in
a laboratory scale. The performance of the systems is
evaluated using several variations of speed and
temperature on the condenser and evaporator sides.
2 METHODOLOGY
2.1 Experimental Setup
he experimental setup of testbed is basically a vapor
pressure system that contain of compressor,
condenser, expansion valve, and evaporator which
can be found in Fig. 1. Three pressure gauge installed
in the system, i.e., at line 1, 2, and 3 to identify low
and high pressure in the system (rated from 0 – 16
kg/cm
2
). Whereas the thermocouple and sight glass
installed in line 1-4, and line 1-2 respectively.
EVAPORATOR
CONDENSER
COM-
PRESSOR
EXPANSION
VALVE
PG
PG
SG
SG
PG
4
1
3 2
FILTER AND
DRYER
Figure 1: Schematic diagram of experimental setup.
We used a hematic compressor with a ½
horsepower rating capacity (340 watts) dismantled
from a ½ HP split air conditioner manufactured by
LG. The motor's input voltage is 220 V at 50Hz with
no inverter mode. We apply R22 refrigerant to the
system as recommended by the compressor
manufacturer. The car condenser was installed in the
testbed with nominal dimensions of 450 x 350 x 25,6
mm with a thermal capacity of 900 J/kg.K, according
to the manufacturer (Pokka). The primary material is
aluminium, with the inlet and outlet connection is ½”
and 3/8” respectively. Induced draft axial fan
installed on the condenser with a diameter of 30 cm
and capacity of 0,178 m3/s, and 72-watt rating power
(or 12 VDC and 6 A).
Figure 2: The experimental setup of testbed, (a) front view, (b) back view.
(a)
(b)
iCAST-ES 2022 - International Conference on Applied Science and Technology on Engineering Science
220
The evaporator installed in the system has a rated
thermal capacity of 900 J/kg.K with ten coiled loops
compacted in a 400 x 165 x 135 mm plastic enclosure.
The fin and the coil are aluminium-based materials
with inlet and outlet connector is 3/8 inch and ½ inch,
respectively. This evaporator is equipped with two
embedded radial fans at the capacity of 72 Watt. The
thermal expansion valve is installed in the system.
Finally, we installed the power meter to measure the
compressor's power. The complete package of an
experimental setup can be seen in Fig. 2.
2.2 Testing Schemes
Three variations of air flow rate out from the
evaporator are controlled by the fan speed. We
measure the velocity and air flow rate using an
airflow meter at the evaporator grill. The set of
velocity (
v
) and airflow rate (q) variations can be seen
in Table 1.
Table 1: Variation of air flow rate out from the evaporator.
Test
number
v
(m/s)
q
(Lps)
1
2.0
15.7
2
3.0
23.6
3
4.0
31.4
The ambiance temperature during the test is
between 28-31
o
C. The performance of the system is
calculated using the coefficient of performance
(COP), as shown in the following equation:
,
where
is the heat absorbed in the evaporator and
is work done by the compressor. The heat
absorbed in the evaporator is the different of enthalpy
of refrigerant entering (
and leaving (
the
evaporator as formulated below:
.
Meanwhile, the work of the compressor is the
difference between of enthalpy of refrigerant entering
(
and leaving (
the compressor as formulated
below:
.
3 RESULT AND DISCUSSION
We have measured the air temperature from the outlet
grill evaporator of various airflow rates as shown in
Fig. 3. The error bar shows the lowest and highest air
temperature measured within nine samples. Those
measured air temperatures are acceptable compared
to the air temperature from most of the exit grill of an
automobile air conditioning system (i.e., 15-18
o
C).
Figure 3: Temperature at outlet grill of evaporator.
Figure 4 shows the plot P-h diagram of the
measured pressure and temperature of the present
system. A slight difference in the enthalpy of work
done by the compressor can be found compared to the
heat absorbed by the evaporator.
100 180 260 340 420 500
Enthalphy (kJ/kg)
80
50
20
5
2
10
R22
Pressure (Bar)
3
4
2
1
Figure 4: P-h diagram of the system.
The effect of various airflow rates in the
evaporator against the refrigerant temperature can be
seen in Table 2. From the table, it shows that the
temperature difference of refrigerant entering and
leaving the evaporator (
1-4
) has about similar value
at various fan speed. It means that the air flow rate in
the evaporator does not affect much on the refrigerant
temperature.
Table 2: The temperature of refrigerant as an effect of
various fan speed in evaporator.
v
(m/s)
Refrigerant temperature (
o
C)
T
1
T
2
T
3
T
4
1-4
2.0
26.5
58.5
33.4
-2.4
28.9
3.0
28.3
59.1
34.0
-0.7
29.0
4.0
29.0
56.6
34.0
0.4
28.6
The effect of refrigeration (
Qc
) and work done by
the compressor (
Wc
) of various evaporator fan speeds
10
12
14
16
18
20
15,7 23,6 31,4
Temperature (
o
C)
Airflow rate at evaporator (Lps)
Experimental Study Combining Electric Powered Compressor in Automobile Air Conditioning System
221
can be seen in Fig. 5. The enthalpy of Qc and Wc in
the system is calculated from the P-h diagram shows
about similar when the fan speed is increased. The
power consumed by the compressor also does not
significantly affect due to the fan speed. The average
power consumption by the compressor is 228,1 ±1,16
watts.
Figure 5: The effect of refrigeration and work done by the
compressor of various evaporator fan speeds.
The performance of the system is measured by
COP which can be seen in Fig. 6. The figure shows
the COP even much greater than 4 where most of air
conditioners in automobile with R22 refrigerant has.
Figure 6: The COP of three variation fan speed.
4 CONCLUSIONS
Combining electric powered compressor in
automobile air conditioning system has been
successfully implemented. The air temperature
leaving the evaporator unit has an acceptable range
proportional to their volume flow. It also found that
the COP of the system does not significantly
influence by the fan speed of the evaporator.
ACKNOWLEDGEMENTS
This work was funded by the Politekhnik Negeri
Jakarta.
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0
100
200
300
400
0
100
200
300
400
2 3 4
Entalphy (kJ/kg)
Velocity (m/s)
Wc
Qc
Power compressor
Power Consumtion (watt)
-
5
10
15
20
2 3 4
COP
Velocity (m/s)
COP
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