The heat pump has a carbon reduction
Time：21/12/28 Source：Zhejiang CEN New Energy Stock CO.,Ltd. Views：
Academician Jiang Yi: The heat pump has a carbon reduction potential of 1.5 billion tons, and there is a lot to do in construction + central heating + industry
From October 11th to 12th, the 2021 China Heat Pump Industry Annual Conference was held in Wuhan. With the theme of "Heat Pump Helping Carbon Neutrality, Industry Development Re-start Sail", more than 1,000 people gathered at the annual meeting to conspire with the development trend of the heat pump industry under the background of the "dual-carbon strategy". Chairman of the China Energy Conservation Association and Academician Jiang Yi of the Chinese Academy of Engineering issued a theme report on "Development Opportunities for the Heat Pump Industry under the Dual-Carbon Target".
In this 50-minute speech, Academician Jiang Yi mainly conveyed the following points:
To achieve carbon neutrality, it is necessary to achieve a zero-carbon energy and low-carbon energy structure based on renewable energy
The opportunity of heat pump technology is that heat pumps are the best way to efficiently convert electricity into heat
The new challenge of heat pump technology is high efficiency, the second is high temperature and dryness, and the third is green working fluid.
Fuel will inevitably appreciate under low-carbon energy conditions, waste heat will become an important resource, and heat pump waste heat recovery is promising
15% of the carbon reduction in the entire society depends on heat pumps. Heat pumps can replace 350 million tons in construction, 100 to 150 million tons in central heating, and 1 billion tons in industrial production.
This article is about 7,700 words, only part of the text is recorded. There are so many essences, please read it patiently. Organized by "Heat Pump Market" magazine based on conference recordings. The opening part and the first part "Characteristics and Challenges of Zero Carbon Energy" are omitted. For the full version, please refer to the follow-up video. (It has been authorized by the organizer to publish, but it has not been reviewed by the speaker himself.)
The heat pump is the best way for the power system to convert into heat efficiently.
In the past, electricity was derived from thermal power. The efficiency of coal-fired power generation was more than 30%, less than 40%, and the efficiency of gas-fired power generation was 50%. Therefore, when heat pumps were used to generate heat, there was a COP limit, saying that COP cannot be used. Too low. For example, if the COP is higher than 2.5, it is cost-effective. Otherwise, your electricity will only generate two heat. If I burn the fire directly, I will produce a lot of heat, and you will lose it. So I set a limit for the heat pump to convert electricity into heat. Only higher than 2.5, or even higher than 3, is better than direct combustion. Thermal energy saving.
This is the era of fossil energy. This is true, and it is in line with our actual conversion process.
But now the situation has changed. Because most of the electricity will not come from thermal power in the future, but from zero-carbon electricity. The task of the heat pump is to convert electricity into heat. What is the reference object? At this time, the reference object is electric heating, not burning fire to generate electricity, so what is the COP of electric heating? It is 1.
In this way, as long as COP>1, is it more energy-efficient than electric heating? The power grid company tried hard to turn on the electric boiler. Its COP is 1. The heat pump must be able to generate heat at the same temperature, and the COP is always greater than 1. Is it more energy-saving than electric heating?
This greatly expands the applicable fields of heat pumps. I hope you will think about it.
Maybe if I say this, someone will probably object, saying that Jiang Yi is wrong, why? Because more than half of the electricity may still come from burning coal, do you think that as soon as the price of coal rises and the price becomes tense, the electricity will be run out if there is no limit to electricity? Why do you think that as long as the COP is greater than 1 energy saving? Originally, the COP should be> 2.5 and COP> 3.
This statement is correct, but we have to develop and see everything. Over the years, through the continuous efforts of various departments, the proportion of thermal power generation has actually gradually decreased. As the composition of thermal power has gradually decreased, the proportion of renewable power has continued to rise, and the corresponding carbon content of each kilowatt-hour of electricity has also been declining.
Like before, it was 100% coal-fired electricity once every kilowatt-hour of electricity, 0.8k/Kg of carbon dioxide, and then 0.8, 0.7, and 0.6 in these years, it should be 0.58 on average in China now. I think the carbon emissions per kilowatt-hour will be 0.58 by the end of this year. The kilograms will be lower.
Second, we are now facing the future. If China must take this path, the future will inevitably be a large proportion of zero-carbon electricity, coming from wind power, photovoltaics, and nuclear power. Then the electricity from this kind of thing should be COP>1, which is energy-saving. Otherwise, if you say that water and electricity will heat me up, what else can you do to make heat?
That side is developing, and we are also developing here. We are developing to look at 10 years later, 15 years later, then 10 years later, I believe that China’s renewable electricity will account for half, and 15 years later, 20 years later, it will be available. Renewable electricity should account for a larger proportion, so this matter should be carried out synchronously. He is engaged in the renewable electrification of electricity, and here it is that my heat is provided by heat pumps. I can’t wait for it to be powered up, saying that the whole process is now green, so you can quickly get the heat pump.
Originally, the heat pump COP>1 would do, but it still doesn’t work. Now I have to get 2.5, which is not the case. We should start the layout now and work hard in that direction. Of course, the higher the COP, the better. However, the COP that was previously excluded from being considered is only a few technologies, and now it should be re-examined.
Looking at it this way, there are challenges in new areas.
What is it first? steam!
Can a heat pump make steam? It is said to make things when it is 70 or 80 degrees hot, like an air source heat pump, can it produce steam? Some people will say that those things are not good, and the COP is only a little bit, which can not save much electricity, but how about COP1.5? 1.3 How about? Doesn't COP1.3 save 30% more energy than electric steam generators? This is also good. So this is also a very important development direction.
Because of the energy revolution, coal-fired and gas-fired boilers have to be eliminated. Now a large number of small and medium-sized boilers burn steam to provide heat in hospitals, hotels, hotels, and laundry rooms, resulting in a large amount of carbon dioxide emissions. Whether the gas pipe burns gas or coal is the object that should be cancelled, so we develop electric heat pumps to generate steam. Can you replace this? As long as it is larger than a little bit, it is energy-saving and worthy of promotion.
For example, if we drink water and heat pump type water boilers, the Chinese have to boil water. Can this be done? Many processes in industrial production require hot water at 70, 80, and 90°C. Can a heat pump be used? Drying fruits requires dry hot air at 40°C to 80°C. At the same time, it is better to recover the heat through the heat pump to recover the drainage and damp hot air. Can these be done?
Some of these contents have been done, some are still being improved, and some are being developed. I think this is a new topic.
So the first is high efficiency, and the second is high temperature and dryness.
What is the third? Under the dual-carbon target, green working fluids must be used.
The "Kigali Amendment" officially entered into force for my country on September 15. For this reason, the Ministry of Ecology and Environment specially organized a meeting to commemorate the major work results achieved in the replacement of working fluids in the previous years. At the same time, it also sounded the clarion call for the implementation of the Kigali Agreement. This is another special work of our heat pumps. It is also related to climate change. Under the dual-carbon goal, green working fluids must be used instead of high-GWP working fluids. High-GWP working fluids will have a greenhouse effect and affect the climate. This is also a new problem that we face in the field of heat pumps.
I stroked it again, there are probably a few different areas, our heat pump can cut into it.
First in the field of construction.
What is included in the field of construction? The construction sector is now to be fully electrified, eliminating coal, oil, and gas. Because now the buildings directly burn coal and natural gas. Burning coal to burn natural gas causes about 600 million tons of carbon dioxide emissions a year, direct emissions, which must be eliminated. This is the first one.
Then the task to be done is that the cooking in our homes and shopping malls may have to be electrified. This is probably not the case with heat pumps, but the electrification of domestic hot water is the application field of heat pumps. Heat pumps are much more efficient than direct electric water heaters.
Replacing electric steam generators in buildings such as hospitals and hotels and directly replacing gas-fired steam boilers in these buildings has become a very important task. Hotels and restaurants are everywhere from south to north. Electric heat pumps must be used to prepare steam and hot water to replace the current coal-fired gas boilers. This is another big deal. This is all about solving the direct carbon emission problem.
There is also indirect carbon emissions, that is, our northern central heating requires a lot of heat energy.
The current heating method is not burning coal in the building or burning coal next to it, or the heat from the boiler room or power plant in the distance, but it needs to emit a large amount of carbon dioxide, which directly leads to the emission of 500 million tons of carbon dioxide a year. This should also be cancelled. In the field of northern central heating, heat pumps can also play a great role.
When talking about the construction sector just now, let's look at the industrial sector again.
CO2 emissions from the industrial sector can be divided into two categories-
One type is for industrial purposes, such as chemical industry. It originally uses natural gas and coal as fuels. That is another way. There are other methods such as steelmaking using coke as a fire fuel, and cement production using coal, which also emits carbon dioxide. It is because it has carbon dioxide coming out and replacing it, which is all technological process. These things seem to be difficult to deal with heat pumps.
In addition, the purpose of non-industrial processes is to use fuel for heat, burning fire for heat.
how many? Probably the industrial sector has about 2.5 billion tons of carbon dioxide emissions per year, which is more than just buildings.
Including the heat demand in the production process of light industry, textiles, printing and dyeing, leather, paper, pharmaceuticals, food, beverage industries, that is, beverages are boiled for disinfection, burned for more than 90 degrees for disinfection, and then cooled down and so on.
Many light industries need to provide about 50 to 110 degrees of heat for heating and disinfection. Industrial production, technological production process, printing and dyeing these things. After production, the final product came out at room temperature, which means that I burned fuel to heat it. After the heat is finished, I have to cool it down after I finish the work. I finally get the product, but where does the heat go? ? The heat has gone to the cooling water, or the cooling air is exhausted immediately. Therefore, these areas are very important areas where our heat pumps can play a good role and use heat pumps to replace fossil fuels with electricity.
Moreover, the heat pump takes low-grade heat to raise it and generates high-grade heat. Since it does not go with the product at this time, and finally it is exhausted, the waste heat is recovered and used as the heat source of the heat pump. At this time, it is possible to efficiently provide heat through the heat pump. Efficient heat preparation has such conditions and resources, so this is a very important field for our heat pumps to enter.
The second chemical production process.
I don’t know anything about chemical production, but you told me that it’s like ethylene. Each ton of ethylene needs 1G joule of heat, and how to heat it. This is what the director of chemistry and chemical engineering told me, as if I thought it was all You don’t use fossil energy or natural gas to produce raw materials. People say that more than half of them are not used as raw materials or for heating.
Then heating sometimes produces a large amount of low-grade waste heat, using 100°C heat, and finally it emits 40~50°C heat and then exhausts it. Therefore, chemical companies have a large number of cooling towers to continuously exhaust heat. Our heat pump has to make good use of this heat, don't be discharged by the cooling tower, and then raise the temperature after taking it back, and then go back to the factory's industrial production process, which is great.
Therefore, in the chemical industry, heat pumps must be very useful. Too many uses high temperature heat here, and discharges slightly lower temperature heat there, and even requires refrigeration there. You combine these processes with heat pumps. , This can replace all fossil energy sources, and solve the problem of the high efficiency of our electric heat pumps.
This is the application of the production process in the chemical industry.
In the mechanical production process, machine manufacturing and many other processes such as electroplating, painting, etc., heat is also needed at this time. At the same time, because it is not too much chemical process, it also needs to exhaust some low-temperature waste heat later. It is also very important to supply this row of low-temperature waste heat through a heat pump.
Furthermore, the application of industrial kilns is also promising. Glass ceramics, including some sintering processes, are all applications in industrial kilns. Well, at this time, these things are very hot, requiring Baidu or even thousands of degrees of temperature.
Some people say that such a high temperature heat pump won't work. It is true that the heat pump cannot directly provide such a high temperature, but if you look at the entire heating process, there is this cold air in front of it, and the air has to be preheated, and then the hot air is discharged there, then if you turn it into electric heating If it is, the cold air in the front is also heated by electricity, but it is not added to a few hundred degrees or thousands of degrees of heat, but a little bit at room temperature. This heating process should be fully capable of the heat pump.
Where to get the heat? Take heat from the wind in the exhaust.
Therefore, in kilns such as glass and ceramics, using heat pumps as two ends, exhaust, heat, preheat, and air intake can save 1/3, which means that it saves more intermediate electric heating. Energy saving plays a big role, so in these kilns, heat pumps are not easy to do, and they can also play a good role.
In addition to heating, the industrial process also includes drying, and the drying process requires a heat pump. Of course, this is not only industrial production, agricultural and sideline product processing, but also drying.
A certain hot pepper production area in Shanxi, every year when the pepper processing and drying season comes, the power supply is tight. If a heat pump is used, the problem of lack of electricity for the pepper drying can be solved.
Including the industrial production process, I know that a company does printing and uses heat pumps for color printing. A heat pump is used in the drying process of the color painting, which has a particularly good effect, improves the quality and reduces energy consumption.
The drying process is not only used for these high-level things, but also for eating, using, and even low-level things, such as sludge drying. The peat is re-turned into burnable coal. These drying processes can also be heated by a heat pump while being recycled. The waste heat emitted has great benefits and is in great demand.
So the characteristic of this kind of thing is that the drying process requires low-temperature waste heat. Where is the low-temperature waste heat? It happens to be the hot and humid air in the row that you dry, and you recycle it to become a good low-temperature heat source for the heat pump.
Of course, there is also the question of whether to add hot air to the drying or to directly heat the dried material. This theory can be analyzed clearly. It is hoped that the dried material can be directly heated, and the efficiency is much higher. But the relationship between heat exchange, how to use the heat pump to output the heat to it, directly to the material to be dried, there are some innovations here, so this trick is to be done carefully.
Then there are many new areas coming out, the very typical one is the data center.
Now we are talking about the new infrastructure, which will build a large number of 4G and 5G base stations. 5G is an electric tiger, so where does all this electricity go? In the end, all came out in the form of heat, and the chip could not store electricity, and all the residual heat at 50°C, 40°C, and 30°C was wasted.
According to data, the data industry consumes 200 billion kilowatt-hours of electricity a year, 200 billion kilowatt-hours of electricity, which is 700 million GJ. What is the concept of 700 million GJ? For our future northern cities in China, 50 GJ will be enough for building heating. This 700 million GJ accounts for 1/7 of it. You have to recover all the heat. 1/7 of the building heating will be enough, saving How many big boilers.
And what is the overall trend now? In order to save energy, the data center continuously raises the temperature of the cooling water. It used to be 7℃ and 10℃, but now it is 15~20℃. The water supply is 15℃ and the return water is 20℃. The cooling water can be satisfied at the temperature. Requested. The hot air discharged from the cabinet is probably higher than 30°C. exist
It is suitable to use heat pump as a low-temperature heat source if it dissipates heat at the required temperature. So one end cools the other
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