Ultra-long distance extremely-low heat loss pipeline and steam conveying system and method thereof

Abstract

The invention discloses an ultra-long-distance extremely-low-heat-loss pipeline and a steam conveying system and method thereof. The pipeline is an integrated finished product pipeline and sequentially comprises a metal inner pipe, an aerogel heat insulation layer, a calcium silicate layer and a polyurethane layer from inside to outside, and the calcium silicate layer is made of CS120 type calcium silicate which is produced by Zhejiang Ask Building Material Technology Co., Ltd. And has the density of 120 kg / m and the hydrophobic rate of 99%; the aerogel heat insulation layer is made of silicon dioxide aerogel and is formed through an in-situ aerogel layer forming process. The system comprises a steam source, a pipeline, a supply terminal, a plurality of electromagnetic induction heating devices, an initial temperature sensor, an outlet temperature sensor, an environment temperature sensor, a flow sensor and a temperature controller. The temperature controller dynamically adjusts the heating power of the plurality of electromagnetic induction heaters.

Description

Technical Field

[0001] The present invention relates to the field of heat transport technology, and in particular to an ultra-long distance extremely low heat loss pipeline and a steam transport system and method thereof. Background Art

[0002] With the adjustment of energy structure and the vigorous development of centralized energy supply, nuclear power as an important clean energy has attracted more and more attention. Due to safety considerations, a large amount of steam emitted by nuclear power plants has not been effectively utilized, resulting in a lot of waste. If nuclear power steam can be used in the petrochemical industry, it can not only greatly reduce carbon emissions, but also save huge costs for petrochemical companies. However, since the area within 20 kilometers around the nuclear power plant is a restricted area, how to safely, stably and efficiently transport a large amount of high-quality steam to petrochemical companies has become a key issue in solving energy waste. Traditional steam pipelines use a single insulation material, such as rock wool and glass wool. The heat loss rate increases significantly with the increase in distance, making it difficult to meet the needs of ultra-long-distance transportation. In addition, in extreme environments such as low temperature and high humidity, the traditional insulation layer is prone to moisture absorption failure, resulting in a decrease in insulation performance. Although the prior art, such as CN202121121519.7 and CN202221206877.2, discloses a composite insulation pipe including an aerogel layer, the former is a calcium silicate tile wrapped with an aerogel layer, and the gaps between the calcium silicate tiles will still cause moisture absorption failure. Although the latter discloses a polyurethane foam layer sleeved on the outside of the calcium silicate insulation layer, it is prefabricated with silica aerogel felt and then attached to the outside of the inner tube. Its production process is complicated, and it causes a large number of seams in the silica aerogel layer, and the thermal insulation performance cannot be guaranteed. Moreover, in the above two invention applications, the performance of calcium silicate cannot meet the technical requirements of ultra-long distance and extremely low heat loss. In addition, the existing compensatory heating technology mostly relies on the booster station or secondary boiler added along the pipeline, which has the defects of high energy consumption, complex operation and maintenance, and large carbon emissions. Summary of the invention

[0003] The present invention provides an ultra-long distance extremely low heat loss pipeline, which is an integrated finished pipeline, and comprises, from the inside to the outside, a metal inner pipe, an aerogel insulation layer, a calcium silicate layer and a polyurethane layer. The material of the calcium silicate layer is CS120 type calcium silicate with a density of 120kg / m³ and a hydrophobicity of 99% produced by Zhejiang Aske Building Materials Technology Co., Ltd.; the aerogel insulation layer adopts silica aerogel and is formed by an in-situ aerogel layer molding process.

[0004] Furthermore, the in-situ aerogel layer forming process specifically includes: plasma spraying the outer surface of the inner tube to form micron-sized pits to increase the adhesion strength of the aerogel; rotating the inner tube to evenly spray the silica sol on the outer surface of the inner tube in a spiral trajectory to form an inner layer of aerogel, and maintaining the gel time for 40min-60min at a temperature of 40°C and a relative humidity of 60%, thereby quickly forming a dense interface to ensure a high-strength bond with the inner tube while blocking the rapid heat conduction of the metal tube wall; rotating the inner tube to evenly spray the silica sol on the outer surface of the inner layer of aerogel in a spiral trajectory to form an outer layer of aerogel, and maintaining the gel time for 120min-150min at a temperature of 25°C and a relative humidity of 30%, thereby obtaining a lower density than the inner layer of aerogel.

[0005] Furthermore, the aerogel insulation layer (3) has a thickness of 5-30 mm and a thermal conductivity of ≤0.018 W / m·K; the calcium silicate layer has a thickness of 20-30 mm and is integrally formed on the outer side of the aerogel layer by a molding process; the polyurethane layer has a thickness of 40-50 mm and is formed by a spraying process; and an aluminum foil reflective film is provided on the outer side of the polyurethane layer.

[0006] The present invention also relates to a steam delivery system using the ultra-long distance and ultra-low heat loss pipeline described above, comprising a steam source, a pipeline, a supply terminal, a plurality of electromagnetic induction heating devices, an initial temperature sensor, an outlet temperature sensor, an ambient temperature sensor, a flow sensor, and a temperature controller; The pipeline is installed overhead, and the steam source transports steam to the supply terminal through the pipeline. The length of the pipeline is greater than 20km; A plurality of electromagnetic induction heaters are installed at equal distances on the outside of the inner pipe of the pipeline, and the distance is less than 500m; The initial temperature sensor is installed at the steam inlet end of the pipeline to detect the initial steam temperature; The outlet temperature sensor is installed at the steam output end of the pipeline to detect the steam outlet temperature; The ambient temperature sensor is installed outside the pipeline to detect the ambient temperature; The flow sensor is installed inside the pipeline to detect the mass flow of steam, and the multiple electromagnetic induction heaters, initial temperature sensors, outlet temperature sensors, ambient temperature sensors, flow sensors are connected to the temperature controller; The temperature controller dynamically adjusts the heating power of multiple electromagnetic induction heaters based on the initial steam temperature, ambient temperature and humidity, and steam flow rate to perform thermal compensation on the steam.

[0007] Furthermore, the temperature controller dynamically adjusts the heating power of the multiple electromagnetic induction heaters specifically including: Calculate total power ,

[0008] Calculate the average power allocated to each induction heater ,

[0009] in, is the total heat transfer coefficient of the pipeline determined according to the thermal insulation performance of the pipeline, is the inner diameter of the inner pipe of the pipeline, is the total length of the pipeline, is the number of electromagnetic induction heaters, is the initial steam temperature, is the ambient temperature and humidity, is the mass flow rate of steam, is the constant pressure specific heat of steam, is a natural constant; The calculation controls the number of Power of an electromagnetic induction heater ,

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016] in, is the steam outlet temperature, is the temperature deviation, , , is the adaptive PID control parameter, is the temperature deviation, is the temperature deviation change rate, is the power compensation amount, is the number counting from the entrance of the pipeline The distance between the electromagnetic induction heater and the pipe inlet, is the control coefficient.

[0017] The present invention also relates to a method for steam transmission using the above steam transmission system, the method comprising the following steps: S1. The steam source inputs steam into the pipeline; S2. The initial temperature sensor detects the initial temperature of the steam, the outlet temperature sensor detects the outlet temperature of the steam, the ambient temperature sensor detects the ambient temperature, the flow sensor detects the mass flow rate of the steam, and sends the above detection amount to the temperature controller; S3. The temperature controller dynamically adjusts the heating power of multiple electromagnetic induction heaters based on the initial temperature of the steam, the ambient temperature and humidity, and the steam flow rate to perform thermal compensation on the steam; Further, the step S3 specifically includes: Calculate total power ,

[0018] Calculate the average power allocated to each induction heater ,

[0019] in, is the total heat transfer coefficient of the pipeline determined according to the thermal insulation performance of the pipeline, is the inner diameter of the inner pipe of the pipeline, is the total length of the pipeline, is the number of electromagnetic induction heaters, is the initial steam temperature, is the ambient temperature and humidity, is the mass flow rate of steam, is the constant pressure specific heat of steam, is a natural constant; The calculation controls the number of Power of an electromagnetic induction heater ,

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] in, is the steam outlet temperature, is the temperature deviation, , , is the adaptive PID control parameter, is the temperature deviation, is the temperature deviation change rate, is the power compensation amount, is the number counting from the entrance of the pipeline The distance between the electromagnetic induction heater and the pipe inlet, is the control coefficient.

[0027] The invention also relates to a computer program product, comprising a computer program, which is executed by a processor for performing a method of steam delivery as described above.

[0028] The present invention also relates to a computer-readable storage medium for storing a computer program, which is executed by a processor for performing the method of steam transmission as described above.

[0029] The technical solution of the present invention adopts a steam pipe with a composite insulation structure of aerogel + calcium silicate + polyurethane, and specifically uses CS120 calcium silicate with a hydrophobicity of 99% and a capacity of 120kg / m³ produced by Zhejiang Aske Building Materials Technology Co., Ltd., and combines a dynamic compensation heating device to heat the steam in the pipe. Under the conditions of transmitting 1.8 MPa, 248 degrees Celsius, and 600 tons / hour of steam in a heating network with a length of not less than 20 kilometers and an annual supply time of not less than 8,000 hours, the temperature loss per kilometer can be controlled to be less than 1°C and the pressure drop to be within 0.03Mpa. 2. Taking the example of a nuclear power plant unit that generates 16-18 billion kWh of electricity annually and emits 4.8 million tons of steam per year, it can save more than 400 million yuan in steam procurement costs for petrochemical companies each year; at the same time, it will reduce the burning of 400,000 tons of standard coal each year, and is equivalent to reducing carbon dioxide emissions by 1.07 million tons, sulfur dioxide by 184 tons, and nitrogen oxides by 263 tons, which is equivalent to an additional afforestation area of ​​2,900 hectares, saving more than 700,000 tons of carbon emissions each year, which has great economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the structure of an ultra-long distance and extremely low heat loss pipeline of the present invention.

[0031] Figure 2 This is a structural block diagram of the ultra-long distance and extremely low heat loss pipeline steam transportation system of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the scope of protection of the present invention. It should be pointed out that the following detailed description is exemplary and is intended to provide further explanation of the present invention.

[0033] Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those generally understood by those of ordinary skill in the art to which the present invention belongs. It should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] Embodiment 1 of the present invention relates to an ultra-long distance extremely low heat loss pipeline, as shown in the attached Figure 1 As shown, the pipeline is an integrated finished pipeline, which includes a metal inner pipe 1, an aerogel insulation layer 2, a calcium silicate layer 3 and a polyurethane layer 4 from the inside to the outside. The material of the calcium silicate layer 3 is CS120 type calcium silicate with a density of 120kg / m³ and a hydrophobicity of 99% produced by Zhejiang Aske Building Materials Technology Co., Ltd.

[0035] The aerogel insulation layer 2 is made of silicon dioxide aerogel and is formed by an in-situ aerogel layer forming process. The thickness of the aerogel insulation layer 2 is 5-30 mm, and the thermal conductivity is ≤0.018 W / m·K.

[0036] The in-situ aerogel layer forming process specifically includes: plasma spraying the outer surface of the inner tube 1 to form micron-sized pits to increase the adhesion strength of the aerogel; rotating the inner tube 1, and evenly spraying the silica sol on the outer surface of the inner tube 1 in a spiral trajectory to form an inner layer of aerogel, and maintaining the gel time for 40min-60min at a temperature of 40°C and a relative humidity of 60%, thereby quickly forming a dense interface to ensure a high-strength bond with the inner tube 1, while blocking the rapid heat conduction of the metal tube wall; rotating the inner tube 1, and evenly spraying the silica sol on the outer surface of the inner layer of aerogel in a spiral trajectory to form an outer layer of aerogel, and maintaining the gel time for 120min-150min at a temperature of 25°C and a relative humidity of 30%, thereby obtaining a lower density than the inner layer of aerogel.

[0037] The calcium silicate layer 3 has a thickness of 20-30 mm and is integrally formed on the outer side of the aerogel layer 2 by a molding process.

[0038] The polyurethane layer 4 has a thickness of 40-50 mm and is formed by a spraying process.

[0039] An aluminum foil reflective film is disposed on the outer side of the polyurethane layer 4 .

[0040] The aerogel layer blocks radiative heat transfer, the calcium silicate layer inhibits convective heat transfer, and the polyurethane layer isolates the intrusion of environmental moisture, so that the total thermal conductivity of the composite structure pipeline of the present invention is significantly reduced. The present invention avoids the seams caused by the pre-compression process of producing aerogel felt through an in-situ aerogel layer forming process including gradient gel control, and avoids moisture absorption failure caused by gaps between calcium silicate tiles through the integrally molded calcium silicate layer.

[0041] Embodiment 2 of the present invention relates to a steam delivery system using the ultra-long distance and ultra-low heat loss pipeline of embodiment 1, as shown in the attached Figure 2 As shown, it includes a steam source, a pipeline, a supply terminal, multiple electromagnetic induction heating devices, an initial temperature sensor, an outlet temperature sensor, an ambient temperature sensor, a flow sensor, and a temperature controller. The pipeline is installed overhead, and the steam source transports steam to the supply terminal through the pipeline, and the length of the pipeline is greater than 20km. Multiple electromagnetic induction heaters are installed at equal distances on the outside of the inner pipe of the pipeline, and the distance is less than 500m. The initial temperature sensor is installed at the steam inlet end of the pipeline to detect the initial temperature of the steam, the outlet temperature sensor is installed at the steam output end of the pipeline to detect the steam outlet temperature, the ambient temperature sensor is installed outside the pipeline to detect the ambient temperature, and the flow sensor is installed inside the pipeline to detect the mass flow of steam. The multiple electromagnetic induction heaters, initial temperature sensors, outlet temperature sensors, ambient temperature sensors, and flow sensors are connected to the temperature controller.

[0042] The temperature controller dynamically adjusts the heating power of multiple electromagnetic induction heaters based on the initial steam temperature, ambient temperature and humidity, and steam flow rate, and performs thermal compensation on the steam, including: Calculate total power ,

[0043] Calculate the average power allocated to each induction heater ,

[0044] in, is the total heat transfer coefficient of the pipeline determined according to the thermal insulation performance of the pipeline, is the inner diameter of the inner pipe of the pipeline, is the total length of the pipeline, is the number of electromagnetic induction heaters, is the initial steam temperature, is the ambient temperature and humidity, is the mass flow rate of steam, is the constant pressure specific heat of steam, is a natural constant.

[0045] The calculation controls the number of Power of an electromagnetic induction heater ,

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052] in, is the steam outlet temperature, is the temperature deviation, , , is the adaptive PID control parameter, is the temperature deviation, is the temperature deviation change rate, is the power compensation amount, is the number counting from the entrance of the pipeline The distance between the electromagnetic induction heater and the pipe inlet, is the control coefficient and can be taken as 0.01.

[0053] According to the control method, it is possible to dynamically adjust the heating power of multiple electromagnetic induction heaters, perform heat compensation on steam, and give priority to compensating the power of the electromagnetic induction heater far from the pipeline inlet.

[0054] Embodiment 3 of the present invention relates to a method for steam transmission using the steam delivery system of embodiment 2, comprising the following steps:

[0055] S1. The steam source inputs steam into the pipeline.

[0056] S2. The initial temperature sensor detects the initial temperature of the steam, the outlet temperature sensor detects the outlet temperature of the steam, the ambient temperature sensor detects the ambient temperature, the flow sensor detects the mass flow of the steam, and sends the above detected quantities to the temperature controller.

[0057] S3. The temperature controller dynamically adjusts the heating power of multiple electromagnetic induction heaters based on the initial temperature of the steam, the ambient temperature and humidity, and the steam flow rate to perform thermal compensation on the steam.

[0058] Step S3 specifically includes:

[0059] Calculate total power ,

[0060] Calculate the average power allocated to each induction heater ,

[0061] in, is the total heat transfer coefficient of the pipeline determined according to the thermal insulation performance of the pipeline, is the inner diameter of the inner pipe of the pipeline, is the total length of the pipeline, is the number of electromagnetic induction heaters, is the initial steam temperature, is the ambient temperature and humidity, is the mass flow rate of steam, is the constant pressure specific heat of steam, is a natural constant.

[0062] The calculation controls the number of Power of an electromagnetic induction heater ,

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069] in, is the steam outlet temperature, is the temperature deviation, , , is the adaptive PID control parameter, is the temperature deviation, is the temperature deviation change rate, is the power compensation amount, is the number counting from the entrance of the pipeline The distance between the electromagnetic induction heater and the pipe inlet, is the control coefficient and can be taken as 0.01.

[0070] Embodiment 4 of the present invention relates to a computer program product, wherein the computer program product comprises a computer program, and the computer program is executed by a processor to perform the steam transmission method of embodiment 3.

[0071] Embodiment 5 of the present invention relates to a computer-readable storage medium, wherein the computer-readable storage medium is used to store a computer program, and the computer program is executed by a processor to perform the steam transmission method of embodiment 3.

[0072] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An ultra-long distance and extremely low heat loss pipeline, characterized in that: The pipeline is an integrated finished pipeline, which comprises, from the inside to the outside, a metal inner pipe (1), an aerogel insulation layer (2), a calcium silicate layer (3) and a polyurethane layer (4). The material of the calcium silicate layer (3) is CS120 calcium silicate with a density of 120 kg / m³ and a hydrophobicity of 99% produced by Zhejiang Aske Building Materials Technology Co., Ltd.; the aerogel insulation layer (3) is made of silicon dioxide aerogel and is formed by an in-situ aerogel layer molding process.

2. The ultra-long distance and extremely low heat loss pipeline according to claim 1 is characterized in that: The in-situ aerogel layer forming process specifically comprises: plasma spraying the outer surface of the inner tube (1) to form micron-sized pits to increase the adhesion strength of the aerogel; rotating the inner tube (1) to uniformly spray the silica sol on the outer surface of the inner tube (1) in a spiral trajectory to form an inner layer of aerogel, and maintaining the gel time for 40 minutes to 60 minutes under the conditions of a temperature of 40° C. and a relative humidity of 60%, thereby quickly forming a dense interface to ensure high-strength bonding with the inner tube (1) and blocking rapid heat conduction of the metal tube wall; rotating the inner tube (1) to uniformly spray the silica sol on the outer surface of the inner layer of aerogel in a spiral trajectory to form an outer layer of aerogel, and maintaining the gel time for 120 minutes to 150 minutes under the conditions of a temperature of 25° C. and a relative humidity of 30%, thereby obtaining a lower density than the inner layer of aerogel.

3. The ultra-long distance and extremely low heat loss pipeline according to claim 1 is characterized in that: The aerogel insulation layer (3) has a thickness of 5-30 mm and a thermal conductivity of ≤0.018 W / m·K; the calcium silicate layer (3) has a thickness of 20-30 mm and is integrally formed on the outside of the aerogel layer (2) by a molding process; the polyurethane layer (4) has a thickness of 40-50 mm and is formed by a spraying process; an aluminum foil reflective film is arranged on the outside of the polyurethane layer (4).

4. A steam delivery system using the ultra-long distance and ultra-low heat loss pipeline according to any one of claims 1 to 3, characterized in that: It includes a steam source, a pipeline, a supply terminal, multiple electromagnetic induction heating devices, an initial temperature sensor, an outlet temperature sensor, an ambient temperature sensor, a flow sensor, and a temperature controller; The pipeline is installed overhead, and the steam source transports steam to the supply terminal through the pipeline. The length of the pipeline is greater than 20km; A plurality of electromagnetic induction heaters are installed at equal distances on the outside of the inner pipe of the pipeline, and the distance is less than 500m; The initial temperature sensor is installed at the steam inlet end of the pipeline to detect the initial steam temperature; The outlet temperature sensor is installed at the steam output end of the pipeline to detect the steam outlet temperature; The ambient temperature sensor is installed outside the pipeline to detect the ambient temperature; The flow sensor is installed inside the pipeline to detect the mass flow of steam, and the multiple electromagnetic induction heaters, initial temperature sensors, outlet temperature sensors, ambient temperature sensors, flow sensors are connected to the temperature controller; The temperature controller dynamically adjusts the heating power of multiple electromagnetic induction heaters based on the initial steam temperature, ambient temperature and humidity, and steam flow rate to perform thermal compensation on the steam.

5. The steam delivery system according to claim 4, characterized in that: The temperature controller dynamically adjusts the heating power of the multiple electromagnetic induction heaters specifically including: Calculate total power , ； Calculate the average power allocated to each induction heater , ； in, is the total heat transfer coefficient of the pipeline determined according to the thermal insulation performance of the pipeline, is the inner diameter of the inner pipe of the pipeline, is the total length of the pipeline, is the number of electromagnetic induction heaters, is the initial steam temperature, is the ambient temperature and humidity, is the mass flow rate of steam, is the constant pressure specific heat of steam, is a natural constant; The calculation controls the number of Power of an electromagnetic induction heater , ； ； ； ； ； ； ； in, is the steam outlet temperature, is the temperature deviation, , , is the adaptive PID control parameter, is the temperature deviation, is the temperature deviation change rate, is the power compensation amount, is the number counting from the entrance of the pipeline The distance between the electromagnetic induction heater and the pipe inlet, is the control coefficient.

6. A method for steam transmission using the steam delivery system according to claim 4 or 5, characterized in that: The method comprises the following steps: S1. The steam source inputs steam into the pipeline; S2. The initial temperature sensor detects the initial temperature of the steam, the outlet temperature sensor detects the outlet temperature of the steam, the ambient temperature sensor detects the ambient temperature, the flow sensor detects the mass flow rate of the steam, and sends the above detection amount to the temperature controller; S3. The temperature controller dynamically adjusts the heating power of multiple electromagnetic induction heaters based on the initial temperature of the steam, the ambient temperature and humidity, and the steam flow rate to perform thermal compensation on the steam.

7. The method of steam transmission according to claim 6, characterized in that: The step S3 specifically includes: Calculate total power , ； Calculate the average power allocated to each induction heater , ； in, is the total heat transfer coefficient of the pipeline determined according to the thermal insulation performance of the pipeline, is the inner diameter of the inner pipe of the pipeline, is the total length of the pipeline, is the number of electromagnetic induction heaters, is the initial steam temperature, is the ambient temperature and humidity, is the mass flow rate of steam, is the constant pressure specific heat of steam, is a natural constant; The calculation controls the number of Power of an electromagnetic induction heater , ； ； ； ； ； ； ； in, is the steam outlet temperature, is the temperature deviation, , , is the adaptive PID control parameter, is the temperature deviation, is the temperature deviation change rate, is the power compensation amount, is the number counting from the entrance of the pipeline The distance between the electromagnetic induction heater and the pipe inlet, is the control coefficient.

8. A computer program product, characterized in that The computer program product comprises a computer program which is executed by a processor for performing the method of steam delivery as claimed in claim 6 or 7.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store a computer program, and the computer program is executed by a processor to perform the steam transmission method according to claim 6 or 7.

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