The multitubular exchanger remains an equipment very well suited to industrial cold production installations of high power, particularly in chemical or petrochemical processes.
Thermal Specifics :
The global project consists in renovating the existing chilled water production units embarked on 4 naval frigates. These ships are each equipped with 4 installations to produce chilled water at a rate of 57.4 m3/h at 6°C from the network, with a return temperature of 12°C. The refrigerant used in these heat exchangers was R11, a fluid that is no longer authorized and the refrigerator manufacturer recommends R134 A. The refrigerant is condensed with sea water, which at certain latitudes can reach a temperature of 32 °C, the value used for the thermal design.
In addition to the thermal performance, the challenge is to offer compact multi-tube heat exchangers that respect the existing dimensions and are able to operate with sea water.
The need for compactness requires the integration of both the condenser and the evaporator in a pressure vessel. This constraint requires the installation of a separator in order to avoid the presence of liquid refrigerant at the compressor suction, but also to design a pressure vessel capable of containing bundles of tubes operating at high pressure (HP, condenser) and another at low pressure (LP, evaporator).
Quelques Données Techniques :
|
|
Evaporator |
Chilled water production |
Condenser |
Cooling fluid |
| Fluid names |
|
R134 A |
water |
R134A |
Sea water |
| Number of passes |
|
1 |
2 |
1 |
2 |
| operating Temperature (inlet / outlet) |
°C |
4 (saturation) |
12 / 6 |
55 /41.7 (saturation) |
43.4 |
75.6 |
| operating pressure |
Bar (a) |
3.36 |
6 |
10.2 |
3 |
| Heat exchange area |
M² |
123.4 |
75.3 |
| Duty |
kW |
400 |
530 |
| Type of bundle tubes |
|
Copper low fin tubes |
Titanium low fin tubes with internal enhancement |
Geometric Specificities :
Horizontal tubular heat exchanger, Type 2 in 1
Constructive Specificities :
Code : AD Merkblätter
Regulation: Germanischer Lloyd
Design temperature: -10°C / +66 °C
Calculation pressures: -1/ 16 bar (g) on channel side and shell side
Test pressures: 44 bar (g) on channel side and shell side.
Welding coefficient 0.85
Material grade :
| |
grade |
standard |
| shell |
P265 GH |
EN 10028-2 |
| tubesheet |
P265 GH + titane |
|
| Channel flanges |
P265 GH |
EN 10028-2 |
| Dishes |
P265 GH |
EN 10028-2 |
| Bundle tubes |
Cuivre et titane |
DIN 1781 +DIN 17671 |
| Nozzles |
Gr6 |
ASTM A333 |
| Baffles |
S235JRG2 |
EN 10025 |
Tube to tubesheet attachments: welded and expanded
Welding processes: EN ISO 15614-1 or EN 288.3 approved
Welders' approvals: According to EN 287.1 or EN 1418
Semi-automatic MIG/MAG processes
Quality Specificities :
LOFC according to customer specifications, requirements of European and local regulations.
Operating file in English and German language
Germanischer Lloyd-certified design and manufacture
Vue 3D :
