Method for measuring heat dissipation of electromechanical device

A method for measuring a heat dissipation of an electromechanical device, comprising following steps of:

• S1. establishing a measuring apparatus,
• the measuring apparatus comprising a housing, wherein a front end of the housing is provided with a gas-tight door for entering and exiting the electromechanical device to be measured;
• an inner center of the housing is provided with a support base for carrying the electromechanical device to be measured;
• a side wall at a bottom of the housing is successively provided with an air inlet for a gas cooling medium to enter, a liquid inlet fora liquid cooling medium to enter, and a liquid outlet for discharging the liquid cooling medium;
• a top of the housing is provided with a gas-collecting hood with an air outlet at a top end;
• and the air inlet, the liquid inlet, the liquid outlet, the air outlet, and an inside wall and an outside wall of the housing are respectively provided with measuring elements;
• S2. measuring and obtaining data, comprising:
• flowing the gas cooling medium in from the air inlet at the bottom and flowing out from the air outlet at the top end after flowing all around the electromechanical device to be measured;
• flowing the liquid cooling medium in from the liquid inlet and out from the liquid outlet after flowing through the electromechanical device to be measured;
• measuring a mass flow m corresponding to each cooling medium through the housing, a temperature T1 of the liquid inlet, a temperature T2 of the liquid outlet, a temperature T3 of the air inlet, a temperature T4 of the air outlet, a temperature T5 of the inside wall of the housing, and a temperature T6 of the outside wall of the housing by using the measuring elements, and measuring a total area A of the inside wall of the housing of the measuring apparatus and a wall thickness L of the housing of the measuring apparatus;
• S3. calculating the heat dissipation Q based on the equation:
• Q=Q1+Q2,
• wherein Q1 represents a heat quantity taken away by the liquid cooling medium and the gas cooling medium, Q2 represents a heat quantity of a convection and radiation heat transfer absorbed by the housing of the measuring apparatus;
• the heat quantity Q1 taken away by the liquid cooling medium and the gas cooling medium being calculated according to the following equation:
• Q
• 1
• =
• Q
• 3
• +
• Q
• 4
• ,
• wherein Q3 represents a heat quantity taken away by the liquid cooling medium, Q4 represents the heat quantity taken away by the gas cooling medium, and calculation equations are respectively as follows:
• Q
• 3
• =
• m
• liquid
• ×
• c
• p
• ,
• liquid
• ×
• (
• T
• 2
• -
• T
• 1
• )
• ,
• Q
• 4
• =
• m
• gas
• ×
• c
• p
• ,
• gas
• ×
• (
• T
• 4
• -
• T
• 3
• )
• ,
• wherein m represents the mass flow of the corresponding cooling medium passing through the housing respectively, cp represents a specific heat capacity of the corresponding cooling medium, T1 and T2 respectively represent the temperatures of the inlet and outlet of the liquid cooling medium, and T3 and T4 respectively represent the temperatures of the inlet and outlet of the gas cooling medium;
• and
• the heat quantity Q2 of the convection and radiation heat transfer absorbed by the body housing of the measuring apparatus being calculated as follows:
• Q
• 2
• =
• k
• ×
• A
• ×
• [
• (
• T
• 5
• -
• T
• 6
• )
• /
• L
• ]
• ,
• wherein k represents a total heat transfer coefficient of the body of the measuring apparatus, A represents the total area of the inside wall of the body of the measuring apparatus, L represents the thickness of the body of the measuring apparatus, and T5 and T6 respectively represent the temperatures of the inside wall and the outside wall of the housing of the measuring apparatus.