Chapter 331: This Can't Be Said
These are also the difficulties that the project team encountered before.
Because the calculations are too complicated, the project team can only roughly estimate a result, and the error from the actual situation cannot be accurately estimated.
Under such conditions, it is difficult to accurately find the most reasonable way to plan superconducting cables.
"Calculating the hysteresis loss of superconducting cables... is really a difficult problem."
Even Xu You had to admit that this problem was not easy to solve.
Xu You tried to derive such a formula through his brain simulation skills.
But after many attempts, this approach didn't work.
Brain simulation can simulate various actual reactions very accurately.
But for the derivation formula, it doesn't work so well.
Xu You decided to derive the formula using traditional methods.
"Let's first identify all the influencing factors."
After careful thinking, Xu You identified all the factors that will affect hysteresis loss.
"Magnetic permeability in vacuum, number of superconducting tapes, frequency, critical current of superconducting tapes, peak value of AC current, critical current degradation rate..."
After determining all the influencing factors, Xu You entered the deep learning state and began to deduce.
Through continuous deduction, Xu You finally discovered that there are some wonderful logarithmic relationships hidden in these physical quantities.
"Construct a new physical quantity Fi, and then calculate the natural logarithm here and here to get the result of the hysteresis loss P..."
In the end, Xu You derived a very complicated formula to calculate the hysteresis loss of superconducting cables.
Through experiments, it was proved that Xu You's derivation result was completely correct.
The calculated value is very close to the measured value, and the error is much smaller than the rough estimate made by the project team before.
Later, Xu You also successfully derived the corresponding formulas for eddy current loss and dielectric loss of the insulation layer.
Next, it is the turn of the superconducting cable's body heat leakage loss.
In order for superconducting materials to realize their superconducting properties, they need to be kept at a relatively low temperature.
In this way, a large temperature difference will be generated inside and outside the insulation layer.
No matter how good the insulation effect of the insulation layer is, heat transfer will definitely occur inside and outside the insulation layer.
Loss calculation at this point is also an essential part.
To this end, it is necessary to measure the thermal conductivity of the insulation layer in detail and calculate the most appropriate cable specifications based on the ambient temperature and superconducting critical temperature.
After a series of derivations, Xu You finally wrote down the following formula:
“P=2πk（T0－T）/ln（D2/D1）”
After the deduction was completed, Xu You couldn't help but sigh:
"The formula for the heat loss of the main body is really concise and clear."
This is the formula with the simplest structure among the several formulas derived by Xu You.
After completing the measurement of the thermal conductivity of the insulation material, Xu You also obtained the optimal specifications for the insulation layer.
"The inner radius is 56mm and the outer radius is 88mm. This will reduce the loss by about 1% compared to the original specifications."
Reducing losses by 1% may seem insignificant.
But in the long term use, it will save a lot of energy.
In all processes, Xu You requires continuous improvement and does not neglect any details.
…
After completing all the formula derivations and calculations, Xu You derived all the optimal conditions and calculated the overall loss of this new superconducting cable.
Xu You found Xing Shuping and explained his calculation results to him.
"Academician Xing, according to my calculations, if we use the optimal solution to lay superconducting cables, the energy loss will be about 29.86% of that of conventional cables."
Hearing this number, Xing Shuping was shocked.
"Professor Xu, is it really possible to achieve such low energy loss?"
You should know that the energy loss of the kilometer-level superconducting cables previously built in Shanghai was about 65.51% of that of conventional cables.
Calculated in this way, this new superconducting cable saves more than half of the energy compared to previous superconducting cables.
"According to my calculations, this is indeed the case. Of course, there will be some errors in the specific performance. This is also related to factors such as the actual ambient temperature."
Because the ambient temperature changes every day and cannot be accurately predicted.
It is certainly impossible to calculate the heat loss of the main body very accurately.
In addition to the advantage of the relatively high superconducting critical temperature of 202K material itself.
Xu You also optimized many other conditions to the greatest extent possible.
Ensure that all losses are controlled at the lowest level.
"I understand. The ambient temperature cannot be accurately controlled. Otherwise, more energy will be consumed. Professor Xu, let's organize a meeting right away. If there are no problems, this plan will be put into construction."
Xing Shuping knew how significant the data calculated by Xu You were.
If in the future we can replace all transmission cables from conventional cables to superconducting cables.
It can save about 70% of energy consumption.
This will have a decisive impact on a country.
In an era of increasingly scarce energy, this technology is undoubtedly revolutionary.
Under the organization of Xing Shuping, everyone immediately came to the conference room and held an emergency meeting.
Xu You was undoubtedly the core of the meeting, talking about his entire design plan for superconducting cables and the results of his calculations.
Xu You's ingenious formula derivation and rigorous calculations conquered all the experts present.
After gaining everyone's unanimous approval, Xing Shuping submitted the design plan to his superiors and obtained their approval.
At this point, the world's largest and most efficient large-capacity superconducting cable will be started in Jijing.
After helping the project team complete the task, Xu You immediately returned to Ji University and did not even attend the celebration banquet.
As for the bonuses and honors that Xu You would receive through this project, Xu You didn't care at all.
This is something very meaningless to Xu You.
But some experts do not have the same qualities as Xu You.
After finishing the celebration banquet for the superconducting project team, Chen Pingqiu did not forget to continue celebrating with the teachers and students of his school's experimental group by having a meal.
“Congratulations to Professor Chen for the success of his project and returning to his alma mater!”
Other teachers and students in the laboratory toasted Chen Pingqiu and expressed their congratulations.
"Professor Chen, what is this project related to?"
"Hey, this is strictly confidential according to the organization. You can't talk about it casually. You will know it naturally when the time comes."
After three rounds of drinks.
Chen Pingqiu finally began to feel drunk.
The excitement caused by being drunk made Chen Pingqiu feel more and more dizzy.
