CN-122020932-A - Performance evaluation method for heat transfer protection effect of pipeline heat insulation coating

CN122020932ACN 122020932 ACN122020932 ACN 122020932ACN-122020932-A

Abstract

The invention provides a performance evaluation method for heat transfer protection effect of a pipeline heat insulation coating, which realizes more accurate characterization of initial heat insulation performance of the coating by introducing an equivalent heat conductivity model based on a microscopic pore structure and overcomes calculation deviation caused by dependence on inherent heat conductivity of a material. And secondly, the model has dynamic prediction capability through coupling performance degradation factors, so that the thermal insulation performance attenuation rule of the coating in the whole life cycle can be accurately simulated, and key data support is provided for energy efficiency evaluation and preventive maintenance of the pipeline. Finally, by defining the comprehensive heat protection efficiency index as an optimization target and reversely optimizing the construction process parameters by utilizing an intelligent algorithm, the traditional experience design is improved to be the accurate optimization design based on performance prediction, so that the material cost is saved to the maximum extent, the energy consumption is reduced, and the safety and the economy of long-term operation of a pipeline system are obviously improved on the premise of ensuring the heat protection effect.

Inventors

SUN QI
LOU ZHENGJI
XU BOWEI
SUN HAONAN
LI JUTAO
JIA BEIBEI
Cheng Yefeng
LI WEI
SHI MINGCHAO
XIONG ANSHUN
CHEN SHENGGUANG
ZHANG XINGYU
CHEN YOUJUN
ZHOU YANG
ZHAI DONGSHENG

Assignees

西安热工研究院有限公司
四川华能宝兴河水电有限责任公司

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (10)

1. The performance evaluation method for the heat transfer protection effect of the heat insulation coating of the pipeline is characterized by comprising the following steps of: s1, acquiring pipeline operation parameters, environment parameters and basic physical parameters of a thermal insulation coating material; S2, based on the basic physical parameters, establishing a pipeline heat loss calculation model considering equivalent heat conductivity of a coating microstructure; S3, introducing a coating performance degradation factor based on time-varying conditions, and correcting the pipeline heat loss calculation model to obtain the pipeline dynamic heat loss rate; s4, defining and calculating the comprehensive heat protection efficiency index of the heat preservation coating to quantitatively evaluate the heat protection effect; And S5, carrying out iterative computation by taking the comprehensive heat protection efficiency index as an optimization target and adjusting construction process parameters or structural parameters of the heat preservation coating, and outputting the optimal coating performance parameters and corresponding process parameters when the index reaches a preset threshold.
2. The method according to claim 1, wherein in step S2, the calculation model taking into account the microstructure equivalent thermal conductivity of the coating is implemented by the following formula: Wherein, the For the equivalent thermal conductivity of the thermal insulation coating, To coat the inherent thermal conductivity of a solid substrate, As a volume fraction of the porosity in the coating, And The structural correction coefficients related to the pore shape and distribution were obtained by fitting experimental data.
3. The method according to claim 2, wherein in the step S2, the pipeline heat loss calculation model is: , Wherein, the Is the total heat loss of the pipe per unit time, For the length of the pipe to be the same, And The temperature of the fluid in the pipeline and the ambient temperature are respectively, And Respectively the inner radius of the pipeline and the outer radius of the outermost heat-insulating layer, Is the first The outer radius of the heat-insulating coating layer, And The heat convection coefficients inside and outside the pipeline are respectively, Is the first Equivalent thermal conductivity of the thermal insulation coating.
4. The method according to claim 1, wherein the performance degradation factor η (t) in step S3 is calculated by the following formula: , Wherein, the The service time of the coating is set; in order for the initial performance factor of the coating to be achieved, As a residual performance factor after the coating performance degradation is stabilized, The dynamic heat loss rate is determined by the performance degradation factor, which is a degradation rate constant related to the weather resistance of the coating material And multiplying the correction coefficient into a heat loss calculation model.
5. The method according to claim 1, wherein in the step S4, the comprehensive thermal protection performance index ψ is calculated as: , Wherein, the And The heat loss rates with the standard and optimized coatings respectively, And The expected service life of the coating after the standard coating and the optimization are adopted respectively, And Is a weight coefficient and satisfies The specific values are determined by the economics of the ducted media and the safety rating requirements.
6. The method of claim 5, wherein the expected lifetime By degrading the coating properties to a critical threshold Time corresponding to time The service life of the coating is determined, and the calculation mode is obtained by inverting the performance degradation factor equation.
7. The method according to claim 1, wherein in the step S5, the construction process parameters to be optimized include the spraying thickness of the coating, the drying and curing temperature curve, and the particle size ratio of the functional filler in the coating system, And the iterative computation adopts a genetic algorithm or a particle swarm optimization algorithm to carry out global optimization in a set parameter space.
8. The method according to claim 1, characterized in that the method further comprises step S6: And taking the optimized coating performance parameters and the optimized process parameters as input, driving the automatic spraying equipment to execute the construction of the heat-insulating coating of the pipeline, and feeding back key parameters in the construction process to a calculation model to realize closed-loop control.
9. An electronic device, comprising: one or more processors; A storage unit for storing one or more programs, which when executed by the one or more processors, enable the one or more processors to implement the performance evaluation method of heat transfer protection effect of a heat insulating coating of a pipe according to any one of claims 1 to 8.
10. A computer-readable storage medium, on which a computer program is stored, characterized in that the computer program, when executed by a processor, is capable of realizing a performance evaluation method of a heat transfer protection effect of a heat insulating coating of a pipe according to any one of claims 1 to 8.

Description

Performance evaluation method for heat transfer protection effect of pipeline heat insulation coating Technical Field The invention relates to the technical field of pipelines, in particular to a performance evaluation method for heat transfer protection effect of a heat insulation coating of a pipeline. Background In the industrial fields of petrochemical industry, district heating, long-distance pipelines and the like, the heat preservation performance of a pipeline system is a core factor for determining the energy efficiency, the operation safety and the economy of the pipeline system. The heat preservation coating is used as a key barrier for isolating the heat exchange between the fluid in the pipeline and the external environment, and the advantages and disadvantages of the heat protection effect are directly related to huge energy loss and operation cost. Currently, the assessment of thermal insulation coating performance in engineering practice is mostly dependent on static thermal conductivity data provided by the material suppliers and is based on simplified steady-state heat transfer models for design calculations. However, the actual thermal conductivity of the coating is significantly affected by its microstructure (e.g., porosity, filler distribution), and during long-term service, performance degradation occurs due to environmental stresses (e.g., thermal cycling, humidity, uv radiation, chemical corrosion), resulting in increased thermal conductivity and reduced thermal insulation. The time-varying degradation effect is ignored in the traditional static design model, so that the performance prediction in the design stage has obvious deviation from the actual operation energy consumption of the pipeline, and hidden danger is buried for energy management and safe production. To address the above challenges, the prior art attempts to reserve a safety margin by increasing insulation thickness or using higher performance materials, but this undoubtedly increases initial investment and material costs. In addition, accelerated aging experiments of the coating are also studied, but the experimental period is long, the cost is high, and the experimental result is difficult to directly and accurately quantify as long-term influence on the heat loss of the whole pipeline. Therefore, a more precise and dynamic calculation method is urgently needed in the field, and the method not only can accurately predict the thermal protection efficiency of the coating in the whole life cycle in the design stage, but also can establish the quantitative relation among the coating material composition, the construction process parameters and the long-term heat preservation performance of the coating, thereby providing scientific basis for the establishment of optimal selection, thickness design and maintenance strategy of the coating and realizing the conversion from 'rough safety margin design' to 'accurate performance guiding design'. Disclosure of Invention In a first aspect of the present disclosure, a performance evaluation method for heat transfer protection effect of a heat insulation coating of a pipeline is provided, including the following steps: s1, acquiring pipeline operation parameters, environment parameters and basic physical parameters of a thermal insulation coating material; S2, based on the basic physical parameters, establishing a pipeline heat loss calculation model considering equivalent heat conductivity of a coating microstructure; S3, introducing a coating performance degradation factor based on time-varying conditions, and correcting the pipeline heat loss calculation model to obtain the pipeline dynamic heat loss rate; s4, defining and calculating the comprehensive heat protection efficiency index of the heat preservation coating to quantitatively evaluate the heat protection effect; And S5, carrying out iterative computation by taking the comprehensive heat protection efficiency index as an optimization target and adjusting construction process parameters or structural parameters of the heat preservation coating, and outputting the optimal coating performance parameters and corresponding process parameters when the index reaches a preset threshold. With reference to the first aspect, in the step S2, the calculation model considering the equivalent thermal conductivity of the microstructure of the coating is implemented by the following formula: Wherein, the For the equivalent thermal conductivity of the thermal insulation coating,To coat the inherent thermal conductivity of a solid substrate,As a volume fraction of the porosity in the coating,AndThe structural correction coefficients related to the pore shape and distribution were obtained by fitting experimental data. With reference to the first aspect, in step S2, the calculation model of heat loss in the pipeline is: , Wherein, the Is the total heat loss of the pipe per unit time,For the length of the pipe to be the same,AndThe temper