What are the advantages of liquid hydrogen and liquid oxygen rocket propulsion?
Liquid hydrogen and liquid oxygen are common liquid industrial gases, each with their own characteristics in terms of chemical properties, applications, storage, and processing
Liquid Hydrogen (LH2):
chemical property:
Hydrogen gas liquefies at extremely low temperatures (-253 ° C).
It is the lightest element in the universe, colorless and odorless, with extremely high combustion heat value.
Purpose:
Mainly used as rocket fuel, especially in the aerospace industry, liquid hydrogen is combined with liquid oxygen as a propellant.
In experimental physics research, liquid hydrogen can be used as a coolant.
Potential energy carriers that may be used in the hydrogen energy economy.
Storage and Handling:
Highly insulated containers are required to maintain a low temperature state, typically using superabsorbent materials.
Due to hydrogen being a flammable gas, strict fire and explosion prevention measures are required for storage and handling.
Liquid Oxygen (LOX):
chemical property:
Oxygen liquefies at extremely low temperatures (-183 ° C).
It is a light blue liquid with strong oxidizing properties.
Purpose:
Mainly used as an oxidizer for rockets, combined with fuel (such as liquid hydrogen) to generate thrust.
In the medical field, liquid oxygen is used for oxygen therapy and respiratory support.
In the steel industry, liquid oxygen is used to increase the combustion temperature to promote the melting of metals.
Storage and Handling:
Highly insulated containers are also required to maintain low temperatures.
Although liquid oxygen itself does not burn, it can strongly support combustion, so it needs to be handled carefully to avoid the risk of fire and explosion.
The combined use of liquid hydrogen and liquid oxygen:
Liquid hydrogen and liquid oxygen are often used together as rocket propellants because they can generate extremely high specific impulse (an indicator of propellant efficiency) when combined, providing powerful thrust. This combination is called a "liquid hydrogen liquid oxygen propulsion system" or a "two-component propulsion system". Liquid hydrogen is used as fuel and liquid oxygen is used as oxidant. They mix and burn in the combustion chamber, producing a Large amount of heat energy and water vapor to propel the rocket up. The advantages of this system are high efficiency and environmental friendliness (the combustion product is mainly water), but the disadvantage is that the storage and processing requirements for liquid hydrogen and liquid oxygen are high, and the cost is relatively high.
What are the advantages of liquid hydrogen and liquid oxygen rocket propulsion?
The liquid hydrogen and liquid oxygen rocket propulsion system has the following advantages:
High specific impulse:
Specific impulse is a key indicator for measuring the efficiency of rocket propellants, and the combination of liquid hydrogen and liquid oxygen has a very high specific impulse value, which means they can provide stronger thrust and more efficient fuel consumption.
High energy density:
Liquid hydrogen has a very high combustion heat value, and the energy released per unit mass of hydrogen combustion is much higher than other common fuels, which enables liquid hydrogen liquid oxygen propulsion systems to provide a large amount of energy.
environment protection
The main product of the combustion of liquid hydrogen and liquid oxygen is water vapor, with almost no other harmful emissions, so the impact on the environment is relatively small.
Cooling effect:
Liquid hydrogen can absorb a large amount of heat during vaporization, making it suitable as a coolant for rocket engines and helping to lower the temperature of the combustion chamber.
Reliability and safety:
Both liquid hydrogen and liquid oxygen are relatively stable substances. Although liquid hydrogen is flammable, it will not spontaneously ignite in the absence of oxygen, while liquid oxygen itself does not burn and only supports combustion when mixed with fuel.
Reusability:
With the advancement of technology, the reusability of liquid hydrogen and liquid oxygen rocket propulsion systems is improving, which helps to reduce long-term costs.
Suitable for large rockets:
For deep space missions that require a large amount of propellant, liquid hydrogen and liquid oxygen propulsion systems are an ideal choice due to their high energy density and specific impulse.
Despite the advantages of liquid hydrogen and liquid oxygen rocket propulsion systems, there are also some challenges and limitations, such as:
Difficulty in storage and transportation: Both liquid hydrogen and liquid oxygen need to be stored at extremely low temperatures, which requires highly insulated containers and complex low-temperature technology.
Cost: The production, storage, and transportation costs of liquid hydrogen are relatively high, which increases the overall cost of rocket launch.
Volume and weight: In order to store liquid propellants, larger storage tanks are required, which may increase the volume and weight of the rocket.
Overall, liquid hydrogen and liquid oxygen rocket propulsion systems have significant advantages in performance and environmental friendliness, but face challenges in terms of economy and technological complexity. With the development of technology, these challenges are gradually being overcome.
