How to calculate the air volume of the cooling fan required by the product

For customers, manufacturers are obliged to assist them in how to choose a cooling fan with appropriate air volume. Now the calculation method of air volume demand is introduced as follows: 1. First, some known conditions must be understood: The card is equal to g weight ℃ water to make it The heat required for a temperature rise of °C. The power of watts is equal to Joule per second. , Calorie equals to .joule, air constant pressure (mmAq) specific heat (Cp)u003d.(Kcal/Kg℃), standard state air: humid air with temperature ℃, atmospheric pressure mmHg, humidity% is standard air, and the unit is at this time The weight of volumetric air (also known as specific weight) is g/M*. CMM and CFM refer to the volume of air discharged per minute. The unit of the former is cubic meter/minute; the unit of the latter is cubic feet/minute. CMMu003d.CFM. 2. The formula is calculated and learned: the total heat output of the fan (H) u003d specific heat (Cp) × weight (W) × allowable temperature rise of the container (△Tc) 　　 because: weight W u003d volume between units (per second) multiplied by Density is also: weight Wu003d(CMM/) ×D, which is: weight Wu003d(CMM/)•g/M*, which is: weight Wu003d(Q/) ×g/M* Therefore: total heat (H) u003d.(Q/) •g/M*•△Tc, electrical heat (H)u003d( P[power] t [sec] )/., from one and two: .(Q/) •g/M *•△Tcu003d(P•t)/. Solution: Qu003d(P×)/•.•.•△Tc Solution: Qu003d.P/△Tc…………………………… ………………… (CMM) Solution: Qu003d.•. P/△Tcu003d. P/△Tc……………………(CFM), converted to Fahrenheit (temperature difference per degree Celsius) Equal to. Fahrenheit temperature) is: Qu003d.•. P/△Tfu003d. P/△Tf……………………(CMM) Qu003d.•. P/△Tfu003d. P/△Tf… ………………………(CFM) 3. Example Example 1: A computer consumes watts of power and a fan consumes watts. When the summer temperature is the highest, the CPU is allowed to work at ℃, and the fan air volume is required. The calculation is as follows: Pu003dW+Wu003dW; △Tcu003du003d Qu003d.×/u003d.CMMu003d.CFM (air volume required for work) Example 2: A SWITCHING power supply consumes power watts, a fan consumes watts, local The highest temperature in summer is ℃, and the supply is allowed to work at ℃. The required fan air volume is calculated as follows: 　 Pu003dW+Wu003dW; △Tfu003du003d　 Qu003d.×/u003d.CMMu003d.CFM (air volume required for work) In this way, the main parameter of the air volume of the cooling fan required by the product can be confirmed, and then the cooling fan that fits the customer's product can basically be selected through other parameters. (Recommended reading 'Introduction to Wind Tunnel Laboratory and How to Choose a Cooling Fan')