Examples of troubleshooting methods for cooling wa

Examples of troubleshooting methods for cooling water circulation system of large pump stations

(I) circulating water pump failure

1 Fault phenomenon

the upper computer displays the alarm of low cooling water pressure when the pump is started or running

2. Possible consequences

(1) the pump cannot be started normally

(2) the pump in normal operation trips and stops running

3. Cause and solution

cause 1:

the cooling water pressure provided by the circulating water pump in operation does not reach the pressure value required for the normal startup and operation of the pump

solution:

increase the circulating water pump to make the cooling water pressure reach the pressure required for the normal startup and operation of the pump

reason 2:

a circulating water pump in operation fails, and the cooling water pressure cannot reach the normal value

solution:

switch another normal circulating water pump to ensure the supply of cooling water. Take safety measures, close the gate valve of the inlet and outlet pipes of the faulty cooling water circulating pump, check its check valve, gate valve, bearing, impeller, motor and mechanical seal ring, repair the damaged parts and eliminate the resulting faults

(II) circulating cooling water inlet and outlet pipe failure

1 Fault phenomenon

the upper computer displays the alarm of low cooling water pressure when the pump is started or running

2. Possible consequences

(1) the pump cannot be started normally

(2) the pump in normal operation trips and stops running

3. Cause

the inlet and outlet pipes are blocked, and the outlet pressure cannot meet the requirements for starting the unit

4. Solution

dredge the blocked pipeline to see whether the operation design is reasonable, whether the cleaning is simple and convenient, and ensure the smooth flow of water

(III) non operating circulating water pump check valve fault

1 Fault phenomenon

the upper computer displays the alarm of low cooling water pressure when the pump is started or running

2. Possible consequences

(1) the pump cannot be started normally

(2) normal operation stops with the tripping of pump in electrohydraulic reverse service technology, electrohydraulic proportional technology, microelectronics technology, computer technology and modern control technology

3. Cause

the check valve of the non operating circulating water pump cannot be closed, and the circulating water backflow reverses the non operating circulating water pump, causing the cooling water pressure to decrease

4. Solution

repair or replace the check valve to solve the problem of reverse rotation of circulating water pump caused by this

(IV) cooling water solenoid valve fault

1 Fault phenomenon

the control mode switch on the basic cabinet is in the automatic position. After the pump is started, the cooling water solenoid valve is not fully opened, resulting in the pump starting timeout alarm and the unit starting failure

2. Possible consequences

delay the normal pump start-up time, cause the water level to rise, and may cause sewage overflow

3. Cause and solution

cause 1:

there are sundries or rust spots in the cooling water solenoid valve, causing the switch to be stuck, so that the cooling water flow signal cannot be transmitted to the control system

solution:

after stopping the pump, cut off the power supply in the basic cabinet, close the front and rear gate valves of the solenoid valve, open the solenoid valve, remove the sundries or rust spots in the valve and pipeline, and ensure the sensitivity of the solenoid valve switch

reason 2:

the solenoid valve has poor contact with the signal wire, so that the cooling water flow signal cannot be transmitted to the control system

solution:

connect and sort out the signal line of the cooling water solenoid valve to ensure the reliable connection between the solenoid valve and the signal line end

reason 3:

there is a lot of air mixed in the cooling water circulating pipe, which makes the solenoid valve capsule unable to work, resulting in the switch unable to work

solution:

drain the air in the solenoid valve and pipeline, and adjust the opening threshold of the solenoid valve switch

reason 4:

the signal line of the sealing water solenoid valve and the signal line of the flushing water solenoid valve are replaced incorrectly (this situation usually occurs after maintenance)

solution:

replace the signal lines of sealing water and flushing water solenoid valves

(V) failure of external pipe of tap water

1 Fault phenomenon

the upper computer displays the alarm of cooling water and sealing water interruption; The alarm sound and light of the basic cabinet are on

2. Consequences

the temperature of the unit in operation rises rapidly and trips, damaging the pump bearings

3. Cause and solution

cause 1:

the external pipeline is cut off for various reasons

solution:

turn on the booster pump of the reservoir to make up water to ensure that the roof water tank has sufficient water supply

reason 2:

the water pressure of the external pipeline is low, which cannot reach the pressure required to replenish water to the roof tank

solution:

start the pipeline booster pump or reservoir booster pump to replenish water to the roof water tank

(VI) circulating water pump power control box fault

1 Fault phenomenon

the upper computer displays the alarm of cooling water and sealing water interruption; The alarm sound and light of the basic cabinet are on

2. Consequences

the temperature of the unit in operation rises rapidly, damages the bearing of the pump, and trips during the operation of the pump

3. Cause and solution

cause 1:

when switching the power supply, the circulating water pump power control box loses power, making the circulating water pump in operation shut down

solution:

restore the power supply and turn on the circulating water pump again

reason 2:

circulating water pump power control box failure

solution:

check the power supply voltage, circuit breaker, contactor, thermal relay, temperature alarm, control circuit and control mode switch in the power control box to solve the resulting faults

(VII) working pipeline booster pump failure

1 Fault phenomenon

the upper computer displays the alarm of cooling water and sealing water interruption; The alarm sound and light of the basic cabinet are on

2. Consequences

the temperature of the unit in operation rises rapidly, damages the pump bearings, and the protection trips during pump operation

3. Cause and solution

cause 1:

the booster pump of the working pipeline tripped due to failure

solution:

turn on the standby pipeline booster pump, or turn on the bypass pipeline gate valve; Do a good job in various safety measures, maintain the accurate pressure switch WW for swing angle and swing speed control. On the other hand,

block the booster pump

reason 2:

work pipeline booster pump power control box failure

solution:

check the power supply voltage, circuit breaker, contactor, thermal relay, temperature alarm, control circuit and control mode switch in the power control box of the booster pump of the working pipeline, and solve the resulting faults

(VIII) filter (constant flow valve) fault

1 Fault phenomenon

the upper computer shows that the pressure of cooling water and sealing water is low or the alarm is interrupted; The alarm sound and light of the basic cabinet are on

2. Possible consequences

the temperature rise of the unit during operation will damage the bearing of the pump, and the pump will trip during operation

3. Cause

the constant flow valve filter is blocked, affecting the water supply

4. Solution

close the gate valve of the outlet pipe of the roof water tank and the gate valve of the inlet pipe of the circulating water pump, and remove the filter for cleaning

(IX) pressure sensor failure

1 Fault phenomenon

the upper computer displays the alarm of cooling water and sealing water interruption; The alarm sound and light of the basic cabinet are on

2. Possible consequences

unit tripping in operation

3. Cause

pressure sensor failure, resulting in the pressure signal can not be transmitted to the control system, the control system defaults to the low pressure of circulating cooling water

4. Solution

repair and replace the pressure sensor

(x) cooling water tower fan failure

1 Fault phenomenon

the upper computer and basic cabinet display or alarm that the cooling water temperature is high

2. Possible consequences

because the fan cannot work normally, the water temperature cannot drop, causing the temperature of the running unit to rise and the bearing to be damaged

3. Cause and solution

cause 1:

the fan has no power supply

solution:

check the power supply voltage, fuses, circuit breakers, contactors, thermal relays and connecting lines to solve the resulting power failure

reason 2:

the fan is damaged

solution:

measure the insulation resistance of the fan, check the condition of the fan winding, and replace the damaged parts or the whole machine

reason 3:

fan phase loss operation

solution:

check the power control equipment, power lines, wiring terminals, and solve the resulting phase failure

reason 4:

the position of the air volume switch sensor is incorrect

solution:

adjust the position of the air volume switch sensor

reason 5:

the fan signal line is loose and broken

Troubleshooting:

check the signal circuit, connect and sort out the signal circuit

reason 6:

the wiring bolt of a phase in the fan is loose, causing the wiring to touch the housing

Troubleshooting:

tighten the wiring bolts to solve the problem that the fan does not run