Method and system for temperature measurement of fluid in pipe, electronic device and storage medium

1 . A method for temperature measurement of fluid in a pipe, comprising:

determining fixed parameters and process parameters of an object to be measured; wherein the object to be measured is a pipe with fluid therein; the fixed parameters comprise a flow rate of the fluid, a wall thickness of the pipe, a thermal conductivity of a wall material of the pipe, a convective heat transfer coefficient of the fluid and a convective heat transfer coefficient of an outer air; the process parameters comprise a noise variance and an observation variance;

acquiring an outer air temperature and an outer wall temperature of the pipe at a current moment;

determining a predicted temperature at the current moment according to an optimal internal pipe temperature and a flow rate of the fluid at a previous moment;

determining a covariance at the current moment according to the noise variance and an optimal covariance at the previous moment, wherein the optimal covariance at the previous moment is determined according to a weight coefficient at the previous moment, a covariance at the previous moment, the fixed parameters and the observation variance; and an optimal internal pipe temperature, a weight coefficient and a covariance at an initial moment are obtained by initializing the parameters of the object to be measured;

determining a weight coefficient at the current moment according to the fixed parameters, the observation variance and the covariance at the current moment; and

determining an optimal internal pipe fluid temperature at the current moment according to the predicted temperature at the current moment, the weight coefficient at the current moment, the outer wall temperature of the pipe at the current moment, the air temperature at the current moment, the fixed parameters and the observation variance.

2 . The method according to claim 1 , wherein a process for determining the fixed parameters comprises:

acquiring an inner diameter of the pipe, a thermal conductivity of the fluid, the flow rate of the fluid, a kinematic viscosity of the fluid, a thermal conductivity of the air and a length of the pipe;

calculating the convective heat transfer coefficient of the fluid according to a Prandtl coefficient, the inner diameter of the pipe, the thermal conductivity of the fluid, the flow rate of the fluid and the kinematic viscosity of the fluid; and

calculating the convective heat transfer coefficient of the air according to a Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air, the inner diameter of the pipe and the length of the pipe.

3 . The method according to claim 2 , wherein the calculating the convective heat transfer coefficient of the air according to the Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air, the inner diameter of the pipe and the length of the pipe comprises:

determining whether the pipe is a horizontal pipe or a vertical pipe;

determining the convective heat transfer coefficient of the air according to the Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air and the inner diameter of the pipe when the pipe is the horizontal pipe; and

determining the convective heat transfer coefficient of the air according to the Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air and the length of the pipe when the pipe is the vertical pipe.

4 . An electronic device, comprising: one or more processors; and a memory storage on which one or more programs are stored;

wherein the one or more programs, when executed by the one or more processors, cause the one or more processors to implement the method for temperature measurement of fluid in the pipe according to claim 1 .

5 . The electronic device according to claim 4 , wherein a process for determining the fixed parameters comprises:

acquiring an inner diameter of the pipe, a thermal conductivity of the fluid, the flow rate of the fluid, a kinematic viscosity of the fluid, a thermal conductivity of the air and a length of the pipe;

calculating the convective heat transfer coefficient of the fluid according to a Prandtl coefficient, the inner diameter of the pipe, the thermal conductivity of the fluid, the flow rate of the fluid and the kinematic viscosity of the fluid; and

calculating the convective heat transfer coefficient of the air according to a Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air, the inner diameter of the pipe and the length of the pipe.

6 . The electronic device according to claim 5 , wherein the calculating the convective heat transfer coefficient of the air according to the Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air, the inner diameter of the pipe and the length of the pipe comprises:

determining whether the pipe is a horizontal pipe or a vertical pipe;

determining the convective heat transfer coefficient of the air according to the Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air and the inner diameter of the pipe when the pipe is the horizontal pipe; and

determining the convective heat transfer coefficient of the air according to the Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air and the length of the pipe when the pipe is the vertical pipe.

7 . A storage medium on which a computer program is stored thereon, wherein the computer program, when executed by a processor, implements the method for temperature measurement of fluid in the pipe according to claim 1 .

8 . The storage medium according to claim 7 , wherein a process for determining the fixed parameters comprises:

acquiring an inner diameter of the pipe, a thermal conductivity of the fluid, the flow rate of the fluid, a kinematic viscosity of the fluid, a thermal conductivity of the air and a length of the pipe;

calculating the convective heat transfer coefficient of the fluid according to a Prandtl coefficient, the inner diameter of the pipe, the thermal conductivity of the fluid, the flow rate of the fluid and the kinematic viscosity of the fluid; and

calculating the convective heat transfer coefficient of the air according to a Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air, the inner diameter of the pipe and the length of the pipe.

9 . The storage medium according to claim 8 , wherein the calculating the convective heat transfer coefficient of the air according to the Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air, the inner diameter of the pipe and the length of the pipe comprises:

determining whether the pipe is a horizontal pipe or a vertical pipe;

determining the convective heat transfer coefficient of the air according to the Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air and the inner diameter of the pipe when the pipe is the horizontal pipe; and

determining the convective heat transfer coefficient of the air according to the Grashoff criterion number, the Prandtl coefficient, the thermal conductivity of the air and the length of the pipe when the pipe is the vertical pipe.

10 . A system for temperature measurement of fluid in a pipe, wherein the system comprises:

a parameter determining module, configured to determine fixed parameters and process parameters of an object to be measured; wherein the object to be measured is a pipe with fluid therein; the fixed parameters comprise a flow rate of the fluid, a wall thickness of the pipe, a thermal conductivity of a wall material of the pipe, a convective heat transfer coefficient of the fluid and a convective heat transfer coefficient of an outer air; and the process parameters comprise a noise variance and an observation variance;

a temperature acquiring module configured to acquire an outer air temperature and an outer wall temperature of the pipe at a current moment;

a predicted temperature determining module, configured to determine a predicted temperature at the current moment according to an optimal internal pipe temperature and a flow rate of the fluid at a previous moment;

a covariance determining module configured to determine a covariance at the current moment according to the noise variance and an optimal covariance at the previous moment, wherein the optimal covariance at the previous moment is determined according to a weight coefficient at the previous moment, a covariance at the previous moment, the fixed parameters and the observation variance; and an optimal internal pipe temperature, a weight coefficient and a covariance at an initial moment are obtained by initializing the parameters of the object to be measured;

a weight coefficient determining module configured to determine the weight coefficient at the current moment according to the fixed parameters, the observation variance and the covariance at the current moment; and

an optimal internal pipe fluid temperature determining module, configured to determine the optimal internal pipe fluid temperature at the current moment according to the predicted temperature at the current moment, the weight coefficient at the current moment, the outer wall temperature of the pipe at the current moment, the air temperature at the current moment, the fixed parameters and the observation variance.