Denmark is the first country in the world to promote district heating with solar energy storage and thermal storage, and it is also the largest solar energy storage thermal storage district heating market in the world today. At the end of 2016, Denmark's large-scale (with collector area greater than 500 square meters) solar phase-change energy storage and heat storage district heating system collector installed 80% of such systems in the world, about 1.318 million square meters , the total capacity is 922MWth, and the number of solar energy storage and heat storage district heating plants is 110 (most of which belong to combined heat and power boiler + solar energy + phase change heat storage + district heating system). In addition, the planned area of solar phase change energy storage and heat storage district heating collectors reaches 2.692 million square meters. At present, the development of large-scale phase change energy storage and heat storage district heating technology in Denmark is relatively mature.
1. Seasonal heat storage resolves conflicts stability. With the promotion and popularization of renewable energy such as wind power and photovoltaics, two contradictions have become increasingly prominent: one is the contradiction between the instability of renewable energy supply and the stability of demand; the other is the seasonal distribution of solar energy and the seasonal distribution of energy consumption demand mismatches between them. Using solar energy for heating, solar energy resources are few in winter and surplus in summer, but the energy demand is the opposite, and the heating demand is relatively strong in winter. Therefore, this mismatching contradiction requires an energy storage method, that is, energy storage to solve it. Cross-season heat storage is the key technology to solve the above two contradictions. Through large-capacity thermal storage technology, it can achieve:
1. Decoupling of thermoelectric to increase the flexibility of thermal power plants;
2. The organic coupling of various energy sources such as heat and heat pumps can realize long-term and efficient energy storage and achieve the purpose of optimizing clean heating and power supply.
In the picture above, the seasonal hot water storage body is heated by the solar collector . It can realize the full recovery and utilization of the heat of the hot water storage body, achieve the goal of renewable energy heating, and at the same time improve the system economy. The Danish University of Science and Technology attaches great importance to the research and demonstration of high-performance thermal storage technology. As early as 1983, it established the world's first large-scale thermal storage body of 500 cubic meters, which caused a sensation in the academic world.
Second, the development trend of inter-seasonal energy storage and heat storage technology
Pool heat storage, soil source heat storage body, groundwater body heat storage, large-scale phase change energy storage heat storage.
The steel tank thermal storage is not strictly inter-seasonal thermal storage. Because the steel tank heat storage technology has its particularity, the applicable heat storage volume is generally not more than 7000 cubic meters. If the volume of the heat storage body is greatly increased, the effect of the heat storage body can also be achieved, but the related investment and system cost will be greatly increased. Generally, the volume of steel tanks in Nordic countries is less than 7,000 cubic meters.
Regardless of the type of thermal storage technology, The increasing trend of thermal storage . With the increase of the heat storage volume, the unit cost of the heat storage body is reduced and the heat storage performance is greatly improved. As the volume increases, the heat dissipation surface area corresponding to the unit heat storage body decreases rapidly. When the volume of the heat storage body increases from 100 cubic meters to 100,000 cubic meters, the heat dissipation surface area corresponding to the unit heat storage body decreases to 1/12. At the same time, the cost is also greatly reduced, reaching 1/25. Therefore, the larger the volume of the the better the .
Soil source heat storage body, 2. Pool heat storage body, 3. Phase change energy storage heat storage body.
4. Advantages of inter-seasonal energy storage
- Solar energy: provides free thermal energy.
- Heat pump: Valley electricity supply heat energy; fast grid adjustment capability, make full use of preferential electricity price policies; reduce the volume demand of hot water storage.
- Combined heat and power unit: Triple and quadruple power supply is the key support direction of the state; it has the ability to fast power grid peak regulation, and obtains considerable national peak regulation subsidies; realizes thermal and electrolytic coupling.
- Seasonal thermal storage: Increases system flexibility; coupling optimization using different forms of renewable energy. Technical factors
five phase change thermal storage solar district heating plant success
1, advanced efficient large solar collector field
- high collection efficiency;
- collector reliable, maintenance-free;
- collector life Up to 30 years;
- Optimized collector field piping arrangement;
- Preferred collector inclination, orientation, fluid circulation; _li141span span1
- damage.
2, ton seasonal storage body
- low heat loss, heat regenerator optimized recovery of greater than 90%
- The unit heat storage body cost is low;
- The operation is reliable and the system maintenance cost is low.
3, It can comprehensively utilize various renewable energy such as solar energy, wind energy and biomass energy.
6. Enlightenment of inter-season energy storage and heat storage technology to the development of clean heating in my country _ span11p
However, the large-scale promotion of coal-to-electricity and coal-to-gas conversion has certain drawbacks; thermal power plants use heat to determine electricity, and the production capacity is idle in summer, resulting in waste of resources; the characteristics of thermal and electrolytic coupling limit the peak regulation capacity of power plants, which is not conducive to the promotion of renewable energy power generation . Through the seasonal energy storage and heat storage technology, it is possible to realize: thermo-decoupling, increasing the flexibility of the power plant; storing the waste heat of the power plant in summer and taking it in winter, avoiding heat energy waste and improving the economy of the power plant; wind power, solar thermal, heat pump, waste heat and other multi-energy complementarity, improving renewable energy energy utilization.
The Danish government has put forward a very ambitious energy plan: by 2050, all fossil energy sources will be completely replaced, and by 2035, all electricity and heating will be powered by renewable energy, of which solar heating will serve as a more important source of district heating. my country is rich in solar energy resources, and the density of solar energy resources is twice that of Denmark, which is more conducive to the promotion of solar heating.
This is the direction of solar thermal energy. Denmark has a higher dimension than my country at this stage. Can do better. Kudos to Denmark's leading cross-season heat storage project, some of our projects are well done, such as the phase change energy storage of Tianshuai Intelligent Technology. Some are not good. For example, Yuanda's natural gas triple supply in Yan'an and the "ice source heat pump technology" boasted not long ago are debatable. It is better to take heat from cold water than to take heat from minus ten degrees of air. Better, but the energy efficiency of for heating is still not as good as .
It is the right way to store energy across seasons (heat storage in summer and cold storage in winter).And when there is heat, it is ridiculous to not store it when it is hot. In winter, it is ridiculous to grind guns and dig wells when thirsty. Tianshuai Intelligent Technology's cross-season phase change energy storage and heat storage district heating project has done a good job, focusing on cost-effective phase change heat storage materials to heat a huge amount of hot water and store it into a super large thermal insulation pool of 200,000 cubic meters. Learning from Denmark, the scale is very large and comes from behind. Some people argue that there are no conditions for thermal insulation pools. These conditions cannot be waited for by construction. This is the standard configuration of sponge city . The symbol of modern urban underground engineering, our current urban modernization construction cannot be avoided, avoided, or neglected. The conscience project, drainage, water storage, energy storage, serves multiple purposes, must be built, and it is better and faster to build earlier than later. Build better than slow build!
.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-