How Long Does the Aerogel Recover the "High" Cost?

1. Comparison of advantages and disadvantages between traditional insulation materials and aerogels
The most common shortcomings of traditional insulation materials:The thermal conductivity is high and the thermal insulation effect is poor. In many occasions where there is a high requirement for thermal insulation, the thermal insulation design requirements cannot even be met.Due to poor insulation performance, it requires a large package thickness, which is not conducive to the development of energy-saving insulation construction work, and increases the cost of construction work.The heat preservation performance is rapidly degraded, resulting in the heat loss of equipment and pipelines increasing year by year, and the operating cost is increasing year by year; basically, it is replaced every 3 to 4 years, with high maintenance cost and high investment.Many materials have low hydrophobicity, which causes the insulation layer to be wet. In severe cases, it may even cause corrosion under the insulation layer, resulting in thinning of the wall thickness, which may cause safety hazards in the pipeline or equipment.The structure of the material is unstable. After a period of use, the upper and lower sides will be uneven due to gravity. The thickness of the lower part is sometimes twice that of the upper part, resulting in uneven thermal insulation performance and increased heat loss.
Advantages of traditional insulation materials:The price is low, the initial investment cost is low, and the application is not strict for the insulation performance requirements and the temperature difference between the internal and external temperature is small.
Advantages of aerogel insulationLow thermal conductivity, low thermal conductivity at normal temperature and pressure up to 0.020 W·(m·K)-1, good thermal insulation performanceIt has super-hydrophobic properties, excellent water resistance, no moisture, water corrosion and corrosion, no corrosion under the insulation layer;The aerogel insulation felt has good flexibility, compression resistance, small construction thickness, easy installation and maintenance, and has good adaptability to the weak parts of the pipe elbow, valve, tee and the like.Excellent high temperature resistance, general aerogel products can withstand high temperatures of 600 ° C, special process aerogel can withstand 1100 ° C high temperature.Good fire resistance, flame retardant performance up to Class A non-combustible, greatly improving the safety of materials during useShockproof and explosion-proof, excellent sound insulation and sound absorption performance.Excellent aging resistance and dimensional stability, and the service life in normal environment can reach 12-15 years.
Inferiority of aerogel insulation materials:The price is high, the initial investment cost is high, and the pressure is high.In order to reduce the initial investment cost of the aerogel insulation material instead of the traditional insulation material, the aerogel can be used first in the case where the insulation performance is high, the temperature difference between the inside and the outside is large, and the construction difficulty is high. According to the application requirements, aerogel insulation materials and traditional insulation materials can be combined to achieve maximum cost performance.
2. Economic benefits of aerogel felt in long-distance steam pipelineTaking 350 ° C, 4.5 MPa, flow rate 80 t / h, outer diameter of 325 mm steam pipe as an example, design three insulation schemes for comparative insulation performance and economic benefits

Table 1 Insulation material thickness used in various insulation Cases

The aerogel composite insulation effect is calculated according to GB/T 8175-2008 "Test and Evaluation of Equipment and Pipeline Insulation Effect", and is corrected according to experimental and engineering experience. The results of insulation effect of each scheme are as follows:

Table 2 Insulation effect and energy saving rate of each scheme (1Km pipeline as an example

It can be seen from the data in the table that the aerogel composite insulation structure in Case 1 and Case 2 can save energy by 3127.6GJ and 1937.0GJ per 1Km pipeline per year, compared with the traditional insulation structure, with a heat price of 55 yuan/GJ. Calculated, it can be converted into a person's name of 172,000 yuan and 107,000 yuan.

The temperature drop per kilometer of the pipeline is reduced from 6.9 ° C to 4.8 ° C, which means that for the 15 km pipeline, the temperature of the client can be increased by more than 30 ° C. Secondly, the increase of the steam temperature at the user end can increase the steam heat value that can be delivered to the user, and at the same time increase the production capacity and production of the user.

Table 3 Construction cost of three insulation schemes (calculated by 1Km steam pipeline construction)

It can be seen from the above analysis that the aerogel composite insulation structure in Case 1 and Case 2 can be used to recover the incremental one-time investment cost in three years and two years respectively. Assuming that the depreciation period of the steam pipeline is 10 years, the economic benefits of the first and second schemes are 1.2 million yuan and 800,000 yuan respectively.

Conclusion: The special production process of aerogel insulation blanket determines that its price is higher than the conventional insulation materials on the market. Therefore, the one-time investment of aerogel composite insulation structure is relatively large, but from the long-term perspective, gas condensation Glue composite insulation structure can bring greater economic benefits.

3. Economic benefits of aerogel felt in underground pipeline applications

Taking an oil-transport heat pumping station in the northwestern region of China as an example, in the case of the same thickness of the station pipe insulation layer, according to the thermal conductivity of the traditional insulation material and the aerogel insulation material at 20~70 °C, and the station ambient temperature, Influencing factors such as wind speed, pipe length and heating time, according to GB 50264—2013 “Industrial Equipment and Pipeline Thermal Insulation Engineering Design Specification” and heat flow density calculation formula, analyze and calculate the economics of aerogel materials used in pipelines on the site. And the heat and cost savings that can be saved at the station site after using the aerogel material.

Table 4 Thermal conductivity of aerogel insulation materials and traditional insulation materials at 20-70 ° C

According to investigation and research, the cold oil with a temperature of about 20 °C and the hot oil with a temperature of about 50 °C (there are also hot oil pipes with a temperature greater than 50 °C) are kept in the above-ground pipeline of the station. The oil temperature is conservative at 50 °C. Calculate), the length of the hot and cold oil pipelines is about 50% of the total length of the pipelines in the station. The length of the above-ground insulated pipe is 100 m (the average outer diameter of the pipe is D0 = 0.60 m). Therefore, the length of the cold oil pipe and the hot oil pipe can be assumed to be 50 m each.

In addition, because the heat station is located in the northwest region, the climate is relatively cold, and the time for heating the oil is 6-8 months per year. If the heating time is conservatively 6 months, the average temperature of the coldest 2 months is -10 °C, the average temperature of the second cold 2 months is 0 °C, and the average temperature of the warmer 2 months is 10 °C. Take the thickness of the insulation layer as 2cm, then the outer diameter of the insulation layer is D1=0.64 m. The thermal conductivity of the aerogel material and the traditional insulation material are respectively λ aerogel = 0.018 W/(m·K), λ traditional material = 0.04W /(m·K).

Calculation conditions: the insulation layer is 2cm, the cold oil temperature is 20°C, the hot oil temperature is 50°C, and the heat dissipation length of the hot and cold oil pipes is assumed to be 50m each, and the three gradient ambient temperatures (-10°C, 0°C, 10°C) are each 60 days ( The heat loss time is 1440h), and the heat price is 0.348 yuan/kWh.

Table 5 Energy saving with aerogel insulation

The annual heat saving is 23,746 kWh, and the hot price is converted at 0.348 yuan/kWh. The total energy cost for the whole year is 8,264 yuan.

Table 6 The cost of investment and maintenance of aerogel materials and traditional insulation materials m2

According to the calculation results in Table 6, only the energy saved after the use of aerogel materials can be recovered, and the initial investment can be recovered after 4.6 years. In addition, the service life of aerogel materials is far greater than that of traditional thermal insulation materials, which can save the material and labor costs that need to be replaced due to the failure of the insulation layer in the station for 10 to 15 years, which also saves considerable considerable. An expense. The service life of aerated gel materials and traditional insulation materials are 12.5 years and 3.5 years respectively. In 12.5 years, the deployment times of aerogel materials and traditional insulation materials are 1 time and 3.57 times respectively, which can save 2.57 times to deploy traditional insulation. The investment in materials totaled 29,472 yuan, with an average annual savings of 2,358 yuan. If this part of the saved investment is counted as the saved operation and maintenance cost, the sum of the annual energy savings and operation and maintenance costs after using the aerogel material is 10,622 yuan, and the initial investment can be recovered in 3.6 years.

Economic benefit accounting for aerogel insulation materials laid only on 50 °C hot oil pipeline:

Due to the complicated aerogel process, the aerogel price is higher, and the initial investment of replacing the traditional thermal insulation material with aerogel is larger. Secondly, from the energy saving data in Table 5, it can be seen that the aerogel material is in the thermal insulation layer. The cost performance is higher when the temperature difference between the inside and the outside is larger. Therefore, if you want to save initial investment, you can first lay on the pipeline with oil temperature ≥ 50 °C. The investment and maintenance cost of insulation materials in Table 6 is halved. The initial investment increased by using aerogel materials is 18,988 yuan. Only the thermal insulation layer of the hot oil pipeline is replaced with aerogel material, the annual heat saving is 16947kWh, and the hot price is converted by 0.348 yuan/kWh. The total energy cost for the whole year is 5907 yuan. After 3.2 years, it can be recovered due to energy saving and consumption reduction, and the annual energy saving will be 5,907 yuan.

In addition, due to the reduction of the number of times of insulation, the annual operation and maintenance cost can be saved by 1179 yuan. Therefore, by saving heat and replacing the number of insulation layers, the initial investment can be recovered in 2.7 years (compared to the investment with traditional insulation materials). ). It can be seen that if the aerogel material is used only for the hot oil pipeline, the time for recovering the initial increase of the investment is shorter, and the energy saving and cost reduction effect is more remarkable.

Conclusion: By calculating and comparing the thermal insulation performance, initial investment cost, and operation and maintenance cost of aerogel materials and traditional insulation materials, it is found that the use of aerogel materials on pipelines has a greater comprehensive advantage than traditional insulation materials. The energy and operating and maintenance costs of using aerogel materials (mainly replacing the materials and labor costs of traditional insulation) can exceed the initial investment in 2 to 4 years. In the subsequent service process, sustainable savings due to energy savings and reduced insulation replacement times will save pipeline operators. In addition, the use of aerogel materials is more effective when the temperature difference between the inside and outside of the pipe is large, the annual heating time is long, and the fuel or electric energy is increased.