Detailed information on the physical properties and technical parameters and calculation formulas commonly used in flowmeter measurement and calculation are free download
In the measurement and calculation of the flowmeter, the physical properties (physical properties of the fluid) of some fluids are used, which have a great influence on the accuracy of the flow measurement and the selection of the flowmeter. Limited to the length of this book, we only introduce the basic concepts and some simple calculation formulas for these physical parameters. For detailed data, please go to the relevant manuals for inquiries.
1. The density of the flow meter fluid
The density of the fluid is defined by
In the formula: Ï——fluid density, kg/m3;
m——the mass of fluid, kg;
V——Volume of fluid, m3.
(1) Density of flow meter liquid
When the pressure is constant, the liquid density calculation formula is:
Ï=Ï20[1-μ(t-20)]
In the formula: Ï——the density of the liquid at temperature t, kg/m3;
Ï20——The density of the liquid at 20℃, kg/m3;
μ——The volume expansion coefficient of the liquid, 1/℃;
t——The temperature of the liquid, ℃.
When the temperature is constant, the liquid density calculation formula is:
Ï1=Ï0[1-β(Ï0-Ï1)]
Where: Ï1——The density of the liquid at pressure p1, kg/m3;
Ï0——The density of the liquid at pressure p0, kg/m3;
β-the volumetric compressibility of the liquid 1/Mpa;
p0, p1——The pressure of the liquid, Mpa.
Generally, pressure changes have little effect on liquid density, and can be ignored below 5Mpa. However, for hydrocarbons, pressure correction should be carried out even at lower pressures.
(2) Density of flow meter gas
The formula for calculating the density of dry gas under working conditions is:
In the formula: Ï——The density of dry gas under working condition, kg/m3;
Ïn——The density of dry gas under standard conditions (293.15k, 101.325kPa), kg/m3;
p——The absolute pressure of the gas under working condition, kPa;
pn——absolute pressure in standard state, kPa;
T-the absolute temperature of the gas under working conditions, K;
Tn——Absolute temperature under standard conditions, 293.15K;
Zn-the compressibility of the gas in the standard state;
Z——The compressibility of the gas under working conditions.
2. Viscosity of flow meter fluid
The property of the fluid itself to block the relative sliding of its mass is called the viscosity of the fluid. The viscosity of a fluid is measured by viscosity. The viscosity of the same fluid changes with the temperature and pressure of the fluid. Generally, as the temperature rises, the viscosity of the liquid decreases, and the viscosity of the gas increases. Liquid viscosity only needs pressure correction under very high pressure, and gas viscosity has a very close relationship with pressure and temperature. There are two commonly used to characterize fluid viscosity as follows:
(1) Dynamic viscosity
In the formula: η——hydrodynamic viscosity, Pa·s;
τ——internal friction per unit area,
Pa-velocity gradient, 1/s;
u——fluid velocity, m/s;
h——The distance between two fluid layers, m.
(3) Flow meter kinematic viscosity
The ratio of the dynamic viscosity of a fluid to its density is called kinematic viscosity.
In the formula: v-kinematic viscosity.
3. Thermal expansion rate
The thermal expansion rate refers to the relative change rate of the fluid's volume when the temperature of the fluid changes by 1°C, namely:
In the formula: β——The thermal expansion rate of the fluid, 1/℃;
V——The original volume of the fluid, m3;
△V——The volume of fluid expanded due to temperature changes, m3;
△T——fluid temperature change value, ℃.
4. Compression factor
The compressibility refers to the rate of change of the volume when the fluid temperature is constant and the pressure changes, namely:
In the formula: K-fluid compressibility, 1/Pa;
V-fluid volume m3 when the pressure is p;
△V——The change in fluid volume when the pressure increases ?p, m3.
5. Reynolds number
The Reynolds number is a dimensionless quantity that characterizes the ratio of fluid inertial force to viscous force. It is defined as:
Where: v——average velocity of fluid, m/s;
ι——The characteristic length of the flow velocity, such as the pipe inner diameter value in a round pipe, m;
υ——Kinematic viscosity of fluid, m2/s.
If the Reynolds number is small, the viscous force is dominant, and the effect of viscosity on the entire flow field is important. If the Reynolds number is large, the inertial force is the main one, and the effect of viscosity on the flow is important only in the boundary layer or the area with a large velocity gradient.
Bitcoin mining is the process of creating new bitcoin by solving puzzles. It consists of computing systems equipped with specialized chips competing to solve mathematical puzzles. The first bitcoin miner (as these systems are called) to solve the puzzle is rewarded with bitcoin. The mining process also confirms transactions on the cryptocurrency's network and makes them trustworthy.
For a short time after Bitcoin was launched, it was mined on desktop computers with regular central processing units (CPUs). But the process was extremely slow. Now the cryptocurrency is generated using large mining pools spread across many geographies. Bitcoin miners aggregate mining systems that consume massive amounts of electricity to mine the cryptocurrency.In regions where electricity is generated using fossil fuels, bitcoin mining is considered detrimental to the environment. As a result, many bitcoin miners have moved operations to places with renewable sources of energy to reduce Bitcoin's impact on climate change.
Btc Miner,Bitmain S19 Xp,Bitmain Antminer S19 Xp,Antminer Bitmain S19 Xp 140Th
Shenzhen YLHM Technology Co., Ltd. , https://www.hkcryptominer.com