📖 About 3 min read
Flue gas treatment at a coal-fired power plant normally combines three systems: selective catalytic reduction (SCR) for nitrogen oxides, an electrostatic precipitator (ESP) for particulate matter, and flue gas desulfurization (FGD) for sulfur dioxide. DYPNF Co., Ltd. (formerly Dong Yang P&F) carries out design, supply, and installation of all three within a single performance-upgrade scope, with project references at 800 MW x 2-unit and 500 MW x 2-unit coal-fired power plants, as well as separate FGD and ESP projects.
| Category | Environmental Plant |
|---|---|
| Primary cause | Performance responsibility split across separate equipment packages on one gas path |
| Key variables | Gas conditions along the gas path, pressure drop, system interfaces, and outage schedule |
| Fix level | One basic design covering SCR (NOx), ESP (particulate matter), and FGD (SO2) |
| Verification method | Basic design review across the full gas path, carried out in-house |
| Reference base | Integrated SCR, ESP, and FGD scopes at 800 MW x 2 and 500 MW x 2 units, plus separate ESP and FGD projects |
| Related standard | Project- and jurisdiction-specific emission requirements |
How Do SCR, ESP, and FGD Work Together in One Gas Path?
In a typical coal-fired unit, flue gas leaving the boiler passes through the SCR, then the air preheater, the ESP, and the FGD before reaching the stack. Because the three systems sit on the same gas path, the performance of one affects the conditions the next one receives.
| System | Removes | Position in the gas path | Effect on other systems |
|---|---|---|---|
| SCR (selective catalytic reduction) | Nitrogen oxides (NOx) | Upstream of the air preheater | Ammonia slip and SO3 formation can affect equipment downstream |
| ESP (electrostatic precipitator) | Particulate matter (fly ash) | After the air preheater | Dust leaving the ESP becomes the dust load entering the FGD |
| FGD (flue gas desulfurization) | Sulfur dioxide (SO2) | Downstream, before the stack | Adds pressure drop that the draft system must handle |
Why Should an Upgrade Be Engineered as One System?
When SCR, ESP, and FGD upgrades are procured as separate equipment packages, each supplier designs to its own guarantee point. Performance responsibility for the gas path as a whole, the interfaces between systems, and the sequencing of work during plant outages are then left for the owner to coordinate. Engineering the three systems in one scope keeps gas conditions, pressure drop, and interface design within one basic design, and allows construction to be planned around a single outage schedule.
What Does DYPNF’s Reference List Show?
| Plant and units | Capacity | Systems | DYPNF scope |
|---|---|---|---|
| Yeongheung Units 1–2 | 800 MW x 2 units | SCR, ESP, FGD | Design, supply, and installation |
| Taean Units 5–6 | 500 MW x 2 units | SCR, ESP, FGD | Design, supply, and installation |
| Taean Unit 2 (FGD fire restoration) | 500 MW x 1 unit | FGD | Design, supply, and installation |
| Taean Units 1–4 (three FGD performance upgrades) | 500 MW units | FGD | Installation |
| Jeju Units 2 and 3 (two ESP performance upgrades) | 75 MW x 1 unit each | ESP | Design, supply, and installation |
| Samcheok Units 1–2 | 1,050 MW x 2 units | ESP | Design, supply, and installation |
| Samcheonpo Unit 3 (ESP performance upgrade) | 560 MW x 1 unit | ESP | Design, supply, and installation |
DYPNF performs basic design, including process design, with its own engineers, and its organization covers design, fabrication, procurement, construction, and commissioning.
Frequently Asked Questions
Why upgrade SCR, ESP, and FGD together instead of one at a time?
The three systems share one gas path, so a change in one affects the conditions the others receive. Engineering them in one scope keeps performance responsibility, interfaces, and outage planning under one design.
Does DYPNF carry out the basic design itself?
Yes. DYPNF has in-house engineers who perform basic design, including process design, and an organization that manages fabrication, procurement, quality, and construction.
Can DYPNF take on an ESP or FGD project on its own?
Yes. In addition to integrated SCR, ESP, and FGD scopes, DYPNF’s references include separate ESP projects at units from 75 MW to 1,050 MW and separate FGD projects at 500 MW units.
Related Documents
Power plant owners and EPC teams planning flue gas treatment upgrades are welcome to review SCR, ESP, and FGD scope together with DYPNF at the basic design stage.