A B C

A : Load side bearing

B : Pump body

C : Motor side bearing

pump motor

Figure 242-1 Measuring point of vibration of pump

Chapter 13 Environmental Protection Facilities

Article 242-a1 De-NOx and De-SOx equipment

Consistency of NOx and SOxin gas emission to atmospheremust not exceed allowable values specified by Vietnam government.It must be referred to QCVN 5 : 2009ional(Nat technical regulation on ambient air quality) and QCVN 22 : 2009 (National technical regulation on emission of thermal power industry) regardingallowable values. It must be operated -DeNOx and De-SOx equipment at all times and complied with above regulations in case that the gas emission doesn't meet the values without these equipments. In addition, countermeasure in case of rise in NOx concentration due to defect in De-NOx equipment inlet NOx gauge is shown as follows ;

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Case : NOx concentration due to defect in De-NOx equipment inlet NOx gauge

Alarm of “A-De-NOx equipment outlet NOx concentration high” is transmitted.

Alarm of “Chimney inlet NOx concentration high” is transmitted.

It is confirmed following conditions.

-Indicating value of A-De-NOx equipment inlet NOx gauge is decreased.

-A-side ammonia flow rate is decreased compared to B-side one.

It is judged that A-De-NOx equipment inlet NOx gauge has defect according above conditions.

It must be controlled A-De-NOx ammonia flow control valve by manual referring to valve opening of B-side control valve.

It must be requested load dispatch center to keep present load of power plant and maintenance group to repair damaged A-De-NOx equipment inlet NOx gauge.

After maintaining damaged NOx gauge, it must be confirmed status of repaired one and returned power plant to normal operation.

Figure 242-a1-1 Countermeasure in case of rise in NOx concentration

Article 242-a2 Monitoring of consistency of NOx and SOx

In power plants, it must be watched over the operating mode ofDe-NOx and De-SOx equipment strictly so that gas emission meets environmental standards. It must be referred to paragraph 1 and 3

of Article 152 of this Guideline regarding point to be checked at operating and daily patrol and inspection of De-NOx and De-SOx equipment.

Article 243. Dust precipitator

Dust content in gas emission to atmosphere must not exceed allowable calculated values for each power plant. It must be referred to QCVN 5 : 2009 (National technical regulation on ambient air quality) and QCVN 22 : 2009 (National technical regulation on emission of thermal power industry).

It must be operated dust precipitator at all times and complied with above regulationsin case that the gas emission doesn't meet the values without these equipments. In addition, countermeasure in case of rise in dust content is shown as follows;

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Alarm of “dust content high” is transmitted.

It is confirmed following conditions.

-Boiler outlet dust content is increased.

-Operation status of dust content gauge is normal.

-Operation status of electric precipitator is normal.

It is judged that relevant equipments have no defect and boiler outlet dust content is increased due to fuel property.

It must be confirmed combustion status of boiler and conducted combustion adjustment.

It must be taken following countermeasures for electric precipitator.

-Hammering of collecting electrode and discharge electrode

-Adjusting of charging voltage and discharge current

It must be requested load dispatch center to reduce load of power plant rapidly if necessary.

Figure 243-1 Countermeasure in case of rise in dust content

Article 244. Monitoring of dust precipitator

In power plants, it must be watched over the operating mode ofdust precipitator strictly so that gas emission meets environmental standards.It must be referred to paragraph 2 of Article 152 of this

Guideline regarding point to be checked at operating and daily patrol and inspection of dust precipitator.

Article 245. Ash and slag disposal system

It must be ensured during operation of ash and slag disposal system that:

1.To dispose of in a timely manner and continuously

(1)General

Amount of emission for ash and slag depends on fuel consumption (power plant load) and ash content in fuel. Because timing of disposing ash and slag depends on amount of emission for them, it must be paid attention to amount of emission for them during operationof power plant.

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(3) Cinder ash and fly ash

Cinder ashes from economizer and AH and fly ashes from ash collector such as electric precipitator are discharged at each hopper. They are disposed at periodical interval by disposal system. When disposing these ashes from each hopper, there is a possibility that they are blocked up at disposal system. In this case, it must be paid attention to safety for operator and disposal system and taken countermeasure for clearing the blockage.

Photo 245-2 Fly ash disposal system (Vacuum transportation system)

2.To keep safety for equipment and works inside and outside of ash and slag disposal system;

(1)Basic policy

It must be conducted daily patrol and inspection according toprocedures developed by each power plant to protect operator and this system.

(2) Rotary machine

Following many rotary machines are included ash and slag disposal systemIt. must be paid attention to them at daily patrol and inspection.

1)Crasher

2)Pump

3)Blower

4)Classifier

(3)High temperature

There is a possibility that slag, cinder ash and fly ash are high temperature because they are discharged from boiler or ash collector. Thus, it must be paid attention to them when contacting them directly.

3.To prevent water source, air and surrounding areas from being contaminated by ash and wastewater.

(1) General

It must be complied with relevant regulations in Viet Name to protect the environment.

(3) Wastewater

It must be referred to Article 248 of this Guideline and Vol.4 Technical Regulation regarding discharge of wastewater.

Article 246. Check of ash and slag disposal system

It must be checked operation of ash and slag disposal system by daily patrol and inspection. Point to be checked at daily patrol and inspection is shown as follows;

1.It must be conducted daily patrol and inspection according to procedures developed by each power plant.

2.Testers, protection equipment and interlocks

(1)Operation test (if necessary)

(2)Leakage and corrosion of piping

(3)Leakage and corrosion of valves

(4)Corrosion and peeling for painting

3. Pump (ash sluicing (disposal) pump, clinker hopper make up pump, wastewater pump etc.)

(1)Pump outlet pressure etc.

(2)Abnormal noise, abnormal odor, vibration and leakage

(3)Heating, abnormal noise and oil leakage for bearing

(4)Level, change in color and leakage for lubricant oil

(5)Leakage and corrosion of piping

(6)Leakage and corrosion of valves

(7)Corrosion and peeling for painting

4. Strainer before pump (ash sluicing (disposal) pump, clinker hopper make up pump etc.)

(1)Differential pressure etc.

(2)Leakage and corrosion of piping

(3)Leakage and corrosion of valves

(4)Corrosion and peeling for painting

Article 247. Ash pond

It must be checked following provisions regarding operation of ash pond. 1. Checking elevation of the surfaces

It must be checked elevation of the surfaces of ash pond periodically and confirmed variation per hour. 2. Checking depth of settling area

It must be checked depth of settling area of ash pond periodically and confirmed variation per hour. 3. Environmental monitoring

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(1) Monitoring effluent

When ashes are reclaimed ash pond in marine, effluent in this ash pond is discharged.It must

be checked water quality of effluent, confirmed it complies with relevant regulation and discharged effluent to sea.

(2) Countermeasure of anti-scattering for ash

When ashes are reclaimed ash pond, there is a possibility that they are flied in all directions. Thus, it must be taken countermeasure ofanti-scattering for ash such as cover soil and fence etc.

(3) Others

It must be complied with relevant regulations in Viet Name to protect the environment. 4. Effective utilization

Ash is applied to following field for effective utilization to eliminate amount of discharging ash to ash pond and reduce cost of ash pond. It is recommended that effective utilization for ash

Photo 247-1 Ash pond

Article 248. Discharge of wastewater of ash and slag disposal system

Wastewater is discharged from ash and slag disposal systemand includes hazardous substance. Thus, it must be treated them by wastewater treatment system, confirmed quality of them is complied with relevant regulations and released them into rivers or common water ditches. In addition, it must be referred to Article 228 of this Guideline regarding wastewater treatment system wasteand water quality regulation in Vietnam.

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