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In the currently developed hydrogen compression cycle system, hydrogen is compressed through a compressor and stored in a tank at high pressure. In the filling process from A (tube trailer) to B (high-pressure tank), thermal stress in the B arises due to the temperature rise of hydrogen together with the internal pressure increase in the tank. In the study, in order to achieve safe filling, it is necessary to investigate the flow and thermal parameters of the system. Based on the principles of thermodynamics, a thermodynamic prediction model for the temperature change during the hydrogen cycle was established by comprehensively considering the real state of gas, convective heat transfer between hydrogen and the inner wall, heat conduction through the tank wall, and natural convection of the outer wall. Prediction values of temperature, hydrogen charge amountm and heat transfer to the outside were calculated. Additionally, by investigating the performance of the hydrogen refueling station heat exchanger, the heat of the heat exchanger needed to keep the hydrogen temperature within a safe range was calculated. Due to the Joule–Thomson effect, the hydrogen temperature passing through the pressure reducing valve changed, and the changed value in the hydrogen charging cycle was predicted and calculated by calculating the temperature change value at this time. This study provides a theoretical research basis for high-pressure hydrogen energy storage and hydrogenation technology.

With the development of social economy, facing the challenge of depletion of fossil fuel energy, countries in the world have paid close attention to the development of new energy sources in recent years attention is being focused on power engines that use new renewable energy. The Stirling engine is such a power engine. Compared with traditional combustion engines, Stirling engine has the advantages of wide fuel sources, no knocking, high thermal efficiency, low noise, low operating costs, low gas pollution, and high economy. Then, the waste heat can be used to power the Stirling engine. This waste heat will be used in aviation, aerospace, land, ocean, and other fields. The study studied the changes in power and efficiency by changing the ratio according to the dynamic configuration of the Stirling engine and by changing the thermodynamic ratio of the engine. In addition, when installing the regenerator in the Stirling engine system, the changes in output and efficiency were also studied. The results show that the dynamic parameter α is increased, the engine efficiency decreases. When the temperature ratio β increased, the engine efficiency decreased. Then, the efficiency of the Stirling engine with a regenerator was found to be higher than that of the Stirling engine without the regenerator. The results focused on dynamic configuration of the Stirling engine to utilize new renewable energy. This work provides a reliable model and theoretical guidance for improving the FPSE’s performance.

The fast refueling of compressed hydrogen has an important influence on the efficiency and safety of the filling process. Precision measurements of the thermodynamic characteristics of hydrogen under the filling process are becoming more important as hydrogen energy is developed and used. One of the key elements of hydrogen fuel cell vehicles is the on-board hydrogen storage cylinder (HSC). Due to the compression of the hydrogen during filling, there could be a fast increase in temperature. The tank's maximum temperature and maximum fueling pressure are both restricted to less than 358.15 K and 125% of the tank's design pressure for safety reasons. This study revealed the hydrogen temperature rise during refueling and developed a theoretical model for computing the temperature rise in the HSC during the high-pressure refueling procedure. The HSC filling procedure was examined using a theoretical approach. Also, the relationship between the refueling procedure and the temperature change of hydrogen in the type IV tank was investigated. The temperature evolution mechanism of various HSCs was explained, and predictions were made for the minimum precooling temperature needed for hydrogen under various filling scenarios. The results of the theoretical analysis gave a theoretical foundation to the present method for controlling the hydrogen temperature of the gas source in the hydrogenation station, which then enables us to determine the optimum amount of energy needed for cooling hydrogen in the hydrogen refueling station.

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