Appraisal and Test Method for Water Volume of FRP Cooling Tower

Appraisal and Test Method for Water Volume of FRP Cooling Tower

To control water resources, save scarce resources, and achieve full utilization of resources, FRP cooling towers have been widely used. It has corrosion resistance, high strength, light weight, small footprint, and is more convenient for transportation, installation and maintenance. It is especially suitable for cooling water circulation systems such as air conditioning, refrigeration, air compressor stations, heating furnaces and condensation processes. In summary, FRP cooling towers are more and more widely used. Here, I mainly introduce you how to identify and test its water volume:

　　A. The water volume measurement is mostly carried out on the water inlet pipe of the glass fiber reinforced plastic cooling tower. When it cannot be measured on the water inlet pipe, it can also be measured on the water outlet channel of the tower. Generally, ultrasonic flowmeter or pitot tube is used to measure flow on the pipeline; flow meter can be used to measure flow on the outlet channel, and rectangular weir can also be used when the water volume is small. In order to ensure the accuracy of measurement, various measuring instruments require a certain straight pipe section, please refer to the technical regulations. Due to water loss, the amount of water entering the tower is greater than the amount of water leaving the tower.

　　 B. Measurement of air volume The air volume measurement of mechanically ventilated glass fiber reinforced plastic cooling towers is generally carried out in the air duct under the fan. The measurement section can be taken 20 cm under the fan blades. The wind speed here is relatively high, so a Pitot tube and a micromanometer are used for measurement. Generally, 4 radii should be measured, and the direction of the radius is at an angle of 45 degrees with the air inlet.

　　C, water temperature measurement

　　①Into the tower water temperature

　　 Measuring instruments are generally mercury thermometers, thermocouples or resistance thermometers. The natural tower is inside the inlet pipe or the shaft, and the difference between the two is about 0.1°C. The mechanical ventilation cooling tower is on the water inlet vertical pipe, and the cross-flow FRP cooling tower is in the distribution pool.

　　②Water temperature out of the tower

　　 There is a journey from the water entering the tower to the exit of the tower, so the measurement must reach a stable state, otherwise the measured data is unreliable. From a new working condition to a stable state, it takes about 40-60 minutes for the natural tower and 30-40 minutes for the mechanical tower.

　　 The water temperature of the natural tower is on the inner side of the outlet ditch, and multiple measuring points must be arranged for average value. The measuring point of the water temperature at the outlet of the mechanical tower is arranged at the outlet of the pool or on the upper side of the pool with a collecting trough, and then the troughs are connected and measured on the water outlet section. It is not accurate to find the average value of the effluent from multiple sumps.

　　D, atmospheric pressure, wind speed and wind direction measurement

　　 Atmospheric pressure affects evaporative heat dissipation, high pressure evaporates slowly, low pressure evaporates quickly. The atmospheric pressure is measured with an empty box or mercury atmospheric pressure gauge. Wind speed and direction measurement are arranged in the upwind direction of the tower, in an open area, 30-50 meters away from the tower, 1.5-2.0 meters above the ground. The measuring instrument uses a rotating cup anemometer with a wind vane or an anemometer that can record continuously. The natural tower will not be tested when the atmospheric wind speed is greater than 3 meters per second, and the mechanical tower is not tested when the atmospheric wind speed exceeds 4 meters per second.

　　E, ambient air dry and wet bulb temperature measurement

　　 The measurement point of the ambient air dry and wet bulb temperature must avoid the return range of the wet air, so the measurement point is set farther, 30-50 meters away from the tower. The dry and wet bulb temperature should be measured with a mechanically ventilated wet and dry meter. This instrument is equipped with a small fan, and the wind speed through the heat sensing part of the temperature measuring element can reach 2.5 meters per second. The function of ventilation is to correct the influence of radiation, so the thermometer must be placed in the weather pavilion to prevent the sun or other heat radiation at a height of 1.5 to 2.0 meters from the ground.

　　F, dry and wet bulb temperature measurement of the air entering the tower

　　 In the natural tower, this measurement uses the ambient air dry and wet bulb temperature. Mechanically ventilated glass fiber reinforced plastic cooling tower may have hot and humid air backflow, so that the dry and wet bulb temperature of the air entering the tower is different from the value of the ambient air, so it must be measured separately.