Civil Engineering Reference
In-Depth Information
Simultaneously, the PCM being encapsulated in the TES tank gets cooled down
by the flowing chilled water and is frozen completely with time. The warm water
that is cooled at the energy transfer station is pumped into the building air-handling
unit, where the supply air is processed and conditioned as per the design cooling
load requirements of the indoor environment.
At the same time, the return warm water from the energy transfer station gets
mixed with the return water from the LTES tank and is pumped back to the chiller
plant for the commencement of the next cyclic process of cooling.
On the other hand, during the discharging process of LTES system (on-peak
load conditions), a portion of the warm water from the return loop of the chiller
plant is diverted to the LTES tank, where it extracts the cold energy from the PCM
encapsulations. The required cooling energy is then transferred to the warm water
(coming from the building side) and to the energy transfer station.
The chilled water is then supplied to the building air-handling unit and the
discharging process at the LTES system is thus accomplished with complete
melting of the PCMs. In this way, the energy storage and heat transfer performance
of this system is enhanced without losing the thermal comfort to occupants and
energy efficiency in buildings. The specifications of TES tanks, the essential
aspects and the key parameters of various TES systems are summarized in
Tables
6
,
7
,
8
and
9
.
Table 6
Specifications of LHES tanks manufactured commercially (Parameshwaran et al.
2012
)
Volume
(m
3
)
External
diameter
(mm)
Total
length
(mm)
Outer surface
area for
insulation (m
2
)
Inlet/outlet
connections
(mm)
Cradles
required
Weight
measured at
empty (kg)
Volume
of HTF
(m
3
)
Cristopia energy systems (Cristopia)
2
950
2,980
10
40
2
850
0.77
5
1,250
4,280
18
50
2
1,250
1.94
10
1,600
5,240
29
80
2
1,990
3.88
15
1,900
5,610
37
100
2
2,900
5.82
20
1,900
7,400
47
125
3
3,700
7.77
30
2,200
8,285
61
150
3
4,700
11.64
50
2,500
10,640
89
175
4
6,900
19.40
70
3,000
10,425
106
200
4
7,300
27.16
100
3,000
14,770
147
250
6
12,700
38.80
Environmental process systems limited (EPS Ltd.)
5
1,250
3,750
-
50
-
-
-
10
1,600
4,500
-
80
-
-
-
25
2,000
8,000
-
125
-
-
-
50
2,500
10,000
-
150
-
-
-
75
3,000
10,600
-
200
-
-
-
100
3,000
11,100
-
250
-
-
-
