Metal Plate Heat Exchanger And Working Principle
The metal plate heat exchanger can effectively reduce energy consumption and pollution by the waste heat recovery process of a heat exchanger between cold combustion air and high temperature flue gas produced by a boiler, heating furnace, or catalytic combustion furnace.
The metal plate heat exchanger is composed of many mutual parallel plate units that are assembled by certain spacing. The space between 2 adjacent plates formed a flow channel. The 2 faces of the plate formed an air channel and flue gas channel respectively with adjacent 2 plates. The air channels and flue gas channels of the whole heat exchanger unit are alternately permutated, and the flue gas and air exchange the heat alternately between plates. The selection of plate material can be considered based on flue gas temperature and corrosion conditions.
2 Types: Alternative flow type and reverse flow type
Features
- Excellent heat transfer performance. Easy to regulate. The liquid heat transfer coefficient is approximately the same on both sides.
- High compact construction, low metal consumption.
- Larger heat transfer area per volume, small plate’s thickness
Lower resistance. With air flowing between two plates, the metal plate heat exchanger has unobstructed airflow channels. - Easy manufacturing, less welding workload, convenient assembly.
- Wide application. Wide range of applications due to the different types of material available.
- Good sealing and less leaking. According to the test of Xi’an Jiaotong University’s state key laboratory of multi-phase fluid, the leakage rate is only 0.015% when the pressure differential is at 4Kpa.
Case Presentations
The metal plate heat exchanger used in 1 million tons per year aromatics recovery complex unit in PetroChina CO. Ltd (Urumqi)
| Item | Flue gas parameter | Air parameter |
| inlet temperature (℃) | 285 | 7 |
| outlet temperature (before / after) (℃) | 135/100 | 190/235 |
| flow rate (kg/h) | 176786 | 167243 |
| pressure drop (Pa) | 1000 | 800 |
| thermal load (MW) | 9.497 | 9.497 |
| Fuel heat value (kcal/nm3) | 11979 | 11979 |
| fuel price (RMB/nm3) | 3.71 | 3.71 |
| fuel saving total amount (nm3/year) | 5,725,900 | 5,725,900 |
| fuel saving total price (RMB) | approx. 21,243,000 | approx. 21,243,000 |
The metal plate heat exchanger used in 1.5 million tons crude oil unit in Xinhai Group
| Item | Flue gas parameter | Air parameter |
| Inlet temperature | 294 | 20 |
| Outlet temperature | 95 | 240 |
| Flow rate (kg/h) | 10381 | 9900 |
| Pressure drop | ＜800 | ＜800 |
| Heat load (MW) | 0.58 | |
| Fuel heat value (kcal/nm3) | 8529 | |
| Fuel price (RMB/nm3) | 2.71 | |
| Fuel saving amount (nm3/year) | 507,900 | |
| Fuel saving (RMB/year) | 1,376,600 |
