New Energy Storage Scheme of First Flight High-technology-Compressed Carbon Dioxide Molten Salt Energy Storage




At the 2023 China Solar Thermal Power Generation Photothermal Conference, Huang Wenbo, Chairman of the First Aviation Gaoke, mentioned the introduction of high-efficiency energy storage islands in his theme report, unveiling the veil of the new energy storage scheme of the First Aviation Gaoke.


First, molten salt heat storage parameters are good, the potential has yet to be tapped.

Molten salt heat storage is currently the main technology for solar thermal power generation system to achieve energy storage, the first high-tech Dunhuang phase I and phase II solar thermal power station are equipped with self-designed molten salt heat storage system, has been stable operation for more than 7 years and 5 years. It can support 100MW and larger capacity thermoelectric units, can reach more than 30 years of service life, low initial investment cost, and excellent economic and performance parameters.




Second, the first flight of high-tech compressed carbon dioxide molten salt energy storage.

Relying on mature project experience and its own professional and technical advantages in heat exchanger, molten salt and thermal power, combined with its years of technical accumulation in supercritical carbon dioxide power generation technology, Shouhang High-Tech has successfully developed compressed carbon dioxide molten salt energy storage technology and supercritical carbon dioxide power generation technology, and completed the prototype test. The conversion process from front-end electricity to heat and the conversion from back-end heat to electricity are greatly improved, which solves the problem of low electricity-electricity conversion efficiency of molten salt energy storage.


(1) Front End

The front-end electricity-to-heat conversion process uses compressed carbon dioxide high-temperature heat pump to heat molten salt, specifically, the thermal energy of low-temperature heat source is "pumped" to a high-temperature state by reverse circulation using abandoned wind and photovoltaic energy, and stored and converted into high-temperature thermal energy. The use of compressed carbon dioxide high-temperature heat pump technology breaks through the limit of impedance heater energy efficiency (cop)<100%, and improves the conversion efficiency of electricity to heat, it is one of the key cutting-edge technologies for the power system to cut peaks and fill valleys and improve the efficiency and safety of the regional energy system.


(2) Rear end

The conversion of back-end heat to electricity can adopt advanced supercritical carbon dioxide power generation technology to efficiently convert heat energy into electricity. According to different molten salt temperatures and installed capacity, the power-to-electricity conversion efficiency of the whole system can reach 57.5~65.8% in the near future;

In the medium and long term (5 to 10 years), it will reach 65% to 76.6, which is expected to exceed the conversion efficiency of pumped storage.


(3) Advantages

1.Unit watt-hour storage construction cost 2.0 yuan;

2.The service life is up to 30 years;

3.Completely free from geographical restrictions;

4.Capability of short-term large-scale deployment;

5.Molten salt and photothermal have the advantage of natural coupling, if combined with photothermal hot melt salt, molten salt-compressed carbon dioxide energy storage electricity-electricity conversion efficiency is higher.


III. Technical Summary of High Temperature Carbon Dioxide Molten Salt Energy Storage System

1. Large scale-high temperature heat pump

2. Sustainable and environmentally friendly

3. Temperature level (0 - 700 ℃) is an ideal heat source for regional coupling and various applications

4. Unmatched scalability and flexibility

5. Flexible matching with photothermal

6. Significantly reduce civil installation costs

TRL7-based on proven technologies and physical processes

8. Short-to medium-term investment payback period-long life cycle.

9. Huge efficiency improvement space

10. No performance attenuation

11. No energy storage/discharge cycle limit


IV. Scope of Supply of First Flight Gaoke

1. Electric drive high temperature compressor integrated expander

2. Supercritical oxidation power generation system (including carbon dioxide system)

3. Heat Exchanger (PCHE)

4. Pipes, valves, instruments and connecting cables of the whole CO2 circuit

5. Complete molten salt energy storage system (large tank, molten salt pump, valve, etc.)

6. Hot and cold water system

7. Complete electrical equipment, including transformers, VFD, switchgear, etc.

8. Whole plant control system and local control system

9. Final acceptance and on-site inspection of main equipment

10. Installation and commissioning

11. Spotlight collection heat supplement system (optional)