What is the Relationship between Temperature and Flow Rate?
The relationship between flow and temperature depends on the specific scenario. Fluid viscosity changes with temperature, affecting fluidity, and temperature balance is achieved by flow regulation in temperature control systems.
In fluid mechanics, an increase in temperature reduces fluid viscosity and increases flow.
In temperature control systems, flow increases and decreases directly affect heat exchange efficiency and thus adjust temperature.
Temperature changes significantly affect fluid viscosity:
1. High temperature environment: The viscosity of most fluids decreases with increasing temperature, and fluidity increases, thereby improving fluidity. For example, oil is easier to transport after heating.
2. Low temperature environment: The increase in fluid viscosity leads to an increase in flow resistance, which is typically manifested by the decrease in the fluidity of lubricating oil in winter.
The accuracy of the flow meter is significantly affected by the ambient temperature:
1. Conventional equipment: It is usually calibrated at 5℃~50℃. Beyond this range, a measurement error of 0.5%~2% may occur.
2. Special equipment: Flow meters with temperature compensation design can maintain ±0.2% accuracy at -40℃~70℃, and are often used in polar scientific research or high-temperature industrial scenarios.
How do you Measure Air Flow and Temperature?
Sino-Inst has a variety of measuring instruments.
The following instruments can measure gas flow.
Differential pressure flow meter
The differential pressure flow meter is an instrument that measures flow based on the differential pressure generated by the flow detection component installed in the pipeline, the known fluid conditions, and the geometric dimensions of the detection component and the pipeline.
Gas vortex flow meter
The vortex flow meter is a flow meter that forces the fluid to produce a violent vortex by the guide vane. When the fluid enters the diffusion section, the vortex is affected by the backflow, forming a gyroscopic vortex precession phenomenon.
Thermal gas mass flow meter
The gas mass flow controller adopts the principle of capillary heat transfer temperature difference calorimetry.
Coriolis mass flow meter
It works based on the principle of the Coriolis force. It directly measures the mass flow rate of the gas passing through the pipeline, rather than the volume flow rate. So, how do we measure the temperature of the gas?
Measuring the temperature of the gas usually requires a different technology from that of solids or liquids. Because the gas has a lower density, stronger fluidity and the surface is not easy to directly contact.
The following are common gas temperature measurement methods:
Gas expansion temperature sensor
Principle: Based on the principle that the gas expands with temperature changes in a fixed volume, the volume change of the gas is measured to infer the temperature.
Thermal conductivity temperature sensor
Principle: Gases at different temperatures have different thermal conductivity. By measuring the thermal conductivity of the gas, the temperature of the gas can be inferred.
Thermal gas flow temperature sensor
Principle: Based on the heat transfer characteristics of the gas flow, the temperature change of the gas when passing through the thermal element is measured.
Radar temperature sensor:
Principle: Based on the principle of interaction between radar waves and gas molecules, measure the temperature in the gas.
Features: Able to monitor the temperature distribution of the gas in real time. Suitable for inaccessible gases or occasions with high gas flow rate.
In addition to our instrument being able to measure temperature and flow at the same time. It can monitor the flow, pressure and temperature of the gas in real time. It can help users better control the gas flow on-site.
