The location of the system

Generally speaking, the chilled water pump should be located in the front end of the chiller, and the chilled water from the end should be returned to the chiller through the chilled water pump.The cooling water pump is arranged on the water way of the cooling water inlet unit, and the cooling water from the cooling tower is returned to the unit through the cooling water pump.The hot water circulating pump is arranged on the backwater main pipe, and the hot water coming back from the end is returned to the plate heat exchanger through the hot water circulating pump.

Valves before and after pumps

The water pump inlet pipe is connected in turn: butterfly valve - pressure gauge - filter - soft connection;The outlet pipe is connected in turn: soft connection - pressure gauge - check valve - butterfly valve
The installation of the pump
Construction conditions:
1) The water pump installation layer has passed the structural acceptance
2) The relevant axes and elevation lines of the building have been drawn
3) The concrete foundation strength of the water pump has reached 70%.
Water pump leveling
The whole pump is in place on the foundation, and the center line of the frame should coincide with the center line of the foundation. Therefore, the center line position should be marked out on the foundation first when installing.
The methods of water pump leveling are:
(1) Put the level ruler on the axis to measure the axial level, and the deviation is within ±20mm.
(2) With the method of lifting vertical line, measure whether the vertical plane of the flange at the inlet and outlet of the pump is parallel to the vertical line. If not, level it by adjusting the thickness of the cushion iron.
After the water pump motor is leveled, fine stone concrete can be poured into the anchor bolt hole and the gap between the foundation and the water pump seat and rammed, so that the anchor bolt and the foundation are connected as one.The preparation ratio of fine stone concrete is cement: fine sand =1:2 concentricity and levelness should be detected again after secondary pouring to prevent the pump from moving in the process of secondary pouring or tightening anchor bolts.
The head of frequency conversion water pump is determined
The head of frequency conversion supplementary water pump should ensure that the water replenishment pressure is 30 ~ 50kPa higher than the system's water replenishment point pressure, which can also be determined according to the following formula:
Hp = 1.15 (PA + + H2 H1 - rho gh)
Where, -- pressure of system water replenishment point, Pa;
-- Pressure loss of suction line of supplementary water pump, Pa;
-- Pressure loss of the outlet line of the water replenishment pump, Pa;
-- The height of the lowest water level of the supplementary tank above the system's supplementary water point, m;
Densities of water, kg/m³;
Is the acceleration of gravity, m/s2;
Single operation debugging of water pump

(1)before starting: should open the hood with hand first wheel, whether flexible;Open the intake valve and exhaust valve to fill the pump chamber with water, and then close the exhaust valve;Int the motor to determine whether the steering is correct.

(2) Operation: fully open the inlet valve, close the outlet pipeline valve;Switch on the power supply, when the pump speed reaches normal, then open the outlet pipe valve, and adjust to the required operating point;Observe whether there is any abnormal situation after the pump runs. If there is any abnormal situation, stop the pump immediately for inspection, and run it after treatment.

(3) Stop: gradually close the outlet valve, cut off the power supply;When closing the inlet valve;If the ambient temperature is below 0℃, warm measures should be taken.
Precautions for single machine operation

1. The following items should be checked before the trial operation of the pump
Refueling tray: check the oil cup of the pump and fill oil into the hole. The tray moves the coupling. The tray should be flexible and there is no abnormal phenomenon.
The anchor bolt should not be loose;
The lubrication parts have been added lubricating oil, cooling oil has been added to the parts that need cooling;
Each indicator instrument, safety protection device and electronic control device should be sensitive, accurate and reliable;
The steering of the motor should be consistent with the steering of the pump: before power-on, remove the connecting plate (backrest wheel) connecting screw, check the direction of motor rotation after power-on, rotate correctly, and then connect to avoid reversal;
Centrifugal pumps must first be filled with water to start, should not run idle.If the pump center is lower than the water absorption surface, it is not necessary to fill water, only to put the air in the pump.If the pump center is higher than the water absorption surface, should first open the suction pipe valve and vent nozzle, close the discharge pipe valve, until the vent nozzle has water gushing, the speed is normal, then open the valve of the outlet pipe, and adjust the pump to the design condition.
The pump starts under the condition of closing the brake, and the running time should not exceed 2-3 minutes in general. If the time is too long, the liquid in the pump will get hot, which can cause an accident, and the pump should be stopped in time.

2. During the test run of the water pump, the temperature rise of the motor, the operation of the water pump, the pointer value of the pressure gauge and vacuum gauge, and the tightness of the interface shall meet the requirements of the standard specification, as follows:
There should be no abnormal vibration and sound in the operation, the precise sealing parts should not leak, the fastening part should not be loose;
The bearing temperature rise must comply with the equipment specification.The maximum temperature of sliding bearings shall not exceed 70℃, and the maximum temperature of rolling bearings shall not exceed 75℃;
The electronic control device of the water pump safety protection box and all parts of the instrument are sensitive, reliable and accurate;
The continuous test run time of the pump under the design load should not be less than 2h;
The temperature rise of the shaft seal packing should be normal. In the absence of special requirements, the leakage of the ordinary packing should not be greater than 35-60ml/h;
The current and power of the motor should not exceed the rated value;