Tube Trailer Research Articles

Multi-stage Co-planning Model for Power Distribution System and Hydrogen Energy System Under Uncertainties

The increased deployment of electricity-based hydrogen production strengthens the coupling of power distribution system (PDS) and hydrogen energy system (HES). Considering that power to hydrogen (PtH) has great potential to facilitate the usage of renewable energy sources (RESs), the coordination of PDS and HES is important for planning purposes under high RES penetration. To this end, this paper proposes a multi-stage co-planning model for the PDS and HES. For the PDS, investment decisions on network assets and RES are optimized to supply the growing electric load and PtHs. For the HES, capacities of PtHs and hydrogen storages (HSs) are optimally determined to satisfy hydrogen load considering the hydrogen production, tube trailer transportation, and storage constraints. The overall planning problem is formulated as a multistage stochastic optimization model, in which the investment decisions are sequentially made as the uncertainties of electric and hydrogen load growth states are revealed gradually over periods. Case studies validate that the proposed co-planning model can reduce the total planning cost, promote RES consumption, and obtain more flexible decisions under long-term load growth uncertainties.

A multi-period sustainable hydrogen supply chain model considering pipeline routing and carbon emissions: The case study of Oman

This paper presents a mathematical model for a multi-period hydrogen supply chain design problem considering several design features not addressed in other studies. The model is formulated as a mixed-integer program allowing the production and storage facilities to be extended over time. Pipeline and tube trailer transport modes are considered for carrying hydrogen. The model also allows finding the optimal pipeline routes and the number of transport units. The objective is to obtain an efficient supply chain design within a given time frame in a way that the demand and carbon dioxide emissions constraints are satisfied and the total cost is minimized. A computer program is developed to ease the problem-solving process. The computer program extracts the geographical information from Google Maps and solves the problem using an optimization solver. Finally, the applicability of the proposed model is demonstrated in a case study from Oman.

Study on the Relationship between Mechanical Properties and Microstructure of 4130X Steel for Tube Trailer Cylinders after High-Temperature Exposure

Study on the Relationship between Mechanical Properties and Microstructure of 4130X Steel for Tube Trailer Cylinders after High-Temperature Exposure

Quantitative risk assessment of a mobile hydrogen refueling station in Korea

Hydrogen infrastructure is expanding. Mobile hydrogen refueling stations are advantageous because they can be moved between locations to provide refueling. However, there are serious concerns over the risk of various accident scenarios as the refueling stations are transported. In this study, we conduct a quantitative risk assessment of a mobile hydrogen refueling station. Risks that may occur at two refueling locations and the transport path between them are analyzed. Our evaluation reveals that risks are mostly in an acceptable zone and to a lesser degree in a conditionally acceptable zone. The greatest single risk factor is an accident resulting from the rupture of the tube trailer at the refueling site. At sites with no tube trailer and during the transport, the risk is greatest from large leaks from the dispenser or compressed gas facility. The mobile hydrogen refueling station can be safely built within acceptable risk levels.

20 K H2 Physisorption on Metal–Organic Frameworks with Enhanced Dormancy Compared to Liquid Hydrogen Storage

Liquid hydrogen (LH2) is the best way of transporting hydrogen, as its high volumetric energy density translates into a significant reduction in hydrogen transportation and refueling operations expenses. However, the phase transformation from liquid to gaseous hydrogen, due to heat leakage of the LH2 vessel, causes a considerable volume change, results in boil-off losses, and makes long-term storage/transportation problematic. These boil-off losses are a severe drawback for continental transportation through truck tube trailers having evaporative losses of about 3–15% per day (depending on the volume). Herein, hydrogen storage by cryo-adsorption using metal–organic frameworks (MOFs) is proposed as an alternative to reduce boil-off losses and enhance dormancy during continental transportation. The stronger van der Waals interaction operating between adsorbate and adsorbent leads to superdense H2 adsorption, which compensates for the space occupied by the adsorbent skeleton and results in a volumetric storage capacity comparable to that of LH2 tanks (∼96%). Depending on the textural properties of MOFs, H2 desorption can start from 45 K, resulting in an extended dormancy time of the tank system. In addition, the observation of hindered rotational transition (J: 0 → 1) signal in neutron scattering analysis indicates that H2 are firmly attached and highly immobile on the adsorption sites. The hindered rotation by adsorption at 20 K on MOFs also suggests that the intermolecular separation is less than the bulk liquid (even solid) phase.

Experimental and numerical studies on large-volume hoop-wrapped composite cylinders with steel liner under fire conditions

Tube trailer consisting of large-volume hoop-wrapped composite cylinders with steel liner (type II cylinder) has the advantages of light weight and large filling capacity. It is widely used for hydrogen storage and transportation in China. In order to ensure the safety of cylinders under fire exposure, fire tests are conducted for gas cylinders according to the ISO11515 standard. However, test data on the fire performance of type II cylinder are limited and the selection criteria of safety relief devices under fire exposure are unclear. In this paper, fire tests were carried out for the large-volume hoop-wrapped composite cylinder fitted with different pressure relief devices (PRDs). The temperature and pressure in the cylinders during fire tests were obtained. The temperature of PRD was measured by transducers. Besides, the response behaviors of the different PRDs (rupture disk structure and rupture disk–fusible alloy combined structure) in fire were compared. A computational fluid dynamics model was established to verify the experimental results. The results showed that the rupture disk structure generally actuated before the rupture disk–fusible alloy assembly structure for type II cylinder under fire exposure, manifesting that the rupture disk structure is a preferable PRD to be used with the large-volume type II cylinder on tube trailer.

Techno-economic assessment of hydrogen refueling station: A case study in Croatia

Hydrogen refueling station (HRS) capacity and location depend on the users, which makes it difficult to select the most favorable option before potential users are actually identified. As in Croatia, at least for now, there are no hydrogen users, this study considers a wide range of HRS capacities and their different configurations. These include hydrogen production and charging station within one existing wind farm in Croatia or both nearby the users, the hydrogen production within the wind farm and the charging station nearby the users, while hydrogen is delivered to the station with a tube trailer, and configuration of hydrogen production within the wind farm with a mobile charging station in case of several users in different locations. Each HRS configuration is evaluated by the obtained levelized cost of hydrogen depending on the capital, and operation and maintenance costs within the HRS techno-economic analysis provided.

A Cycle Analysis of Flow and Thermal Parameters in the Hydrogen Charging System at the Pressure of 50 MPa

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.

Enhancing resilience of emergency heat and power supply via deployment of LNG tube trailers: A mean-risk optimization approach

Tube trailers are widely used for distributing liquefied natural gas (LNG) through transportation networks. When a snowstorm occurs in winter, bad weather conditions may cause pipeline blockages and restrict the movement of trailers, leading to an LNG disruption of an islanded integrated energy system (IES). Thus, it is necessary to pre-allocate the trailers and LNG to enhance IES’s resilience and support its LNG consumption during a snowstorm. This paper explores the resilience potential of LNG tube trailers and investigates their optimal pre-allocation strategy. At first, the system operation and damages of IES during a snowstorm are modeled. The network reconfiguration helps reconstruct the damaged network, and pre-allocated LNG helps support heat and power supply. Then, risk-averting two-stage stochastic programming is applied to solve the optimal trailer pre-allocation plan. The first stage tries to reduce the cost of LNG consumption and trailer pre-allocation; the second stage tries to avoid losses of heat and electricity loads. Besides, the conditional-value-at-risk is considered in the model to prevent low-probability but heavy-loss-load-shedding events. Note that the proposed model contains many integer variables, making it non-convex and prohibiting duality theory. A penalty-based Gauss–Seidel method is developed to solve this issue. This method decomposes the model into scenario-independent sub-problems that can be solved in parallel and achieve a consistent first-stage decision. The simulation results demonstrate the effectiveness of trailer pre-allocation in the IES’s resilience enhancement.

Online Coordination of LNG Tube Trailer Dispatch and Resilience Restoration of Integrated Power-Gas Distribution Systems

Severe winter storms can damage critical components of integrated power-gas distribution systems (IPGS), such as pulling down distribution lines and freezing gas pipelines/sources, causing electricity and gas supply disruptions. Liquefied natural gas (LNG) has a high energy density and can be transported by trailers, hence has great potential in multi-energy restoration. This paper studies the application of LNG trailers in the IPGS restoration. The process that the post-storm restoration coordinated with the trailer dispatch and the emergency operation is fully explored. The trailer dispatch is modeled as a finite-state machine; An efficient policy is proposed to dynamically update the real-time dispatch strategy without future knowledge of uncertainties. For the emergency operation of IPGS, storm-induced damages are considered in the modeling. Then, an online framework is proposed to satisfy the need for IPGS restoration with trailers. Compared with the offline method, the proposed framework does not require future information, so is adaptive to environmental uncertainty and easy to implement. Also, the framework solves a dedicated problem involving the observed information in a single period, hence enjoys a high computational efficiency. The simulation results demonstrate the potential of LNG trailers in resilience enhancement and validate the efficiency of the proposed method.

Comparative risk assessment of liquefied and gaseous hydrogen refueling stations

Several countries are incentivizing the use of hydrogen (H2) fuel cell vehicles, thereby increasing the number of H2 refueling stations (HRSs), particularly in urban areas with high population density and heavy traffic. Therefore, it is necessary to assess the risks of gaseous H2 refueling stations (GHRSs) and liquefied H2 refueling stations (LHRSs). This study aimed to perform a quantitative risk assessment (QRA) of GHRSs and LHRSs. A comparative study is performed to enhance the decision-making of engineers in setting safety goals and defining design options. A systematic QRA approach is proposed to estimate the likelihood and consequences of hazardous events occurring at HRSs. Consequence analysis results indicate that catastrophic ruptures of tube trailer and liquid hydrogen storage tanks are the worst accidents, as they cause fires and explosions. An assessment of individual and societal risks indicates that LHRSs present a lower hazard risk than GHRSs. However, both station types require additional safety barrier devices for risk reduction, such as detachable couplings, hydrogen detection sensors, and automatic and manual emergency shutdown systems, which are required for risk acceptance.

Risk Assessment Method Combining Independent Protection Layers (IPL) of Layer of Protection Analysis (LOPA) and RISKCURVES Software: Case Study of Hydrogen Refueling Stations in Urban Areas

The commercialization of eco-friendly hydrogen vehicles has elicited attempts to expand hydrogen refueling stations in urban areas; however, safety measures to reduce the risk of jet fires have not been established. The RISKCURVES software was used to evaluate the individual and societal risks of hydrogen refueling stations in urban areas, and the F–N (Frequency–Number of fatalities) curve was used to compare whether the safety measures satisfied international standards. From the results of the analysis, it was found that there is a risk of explosion in the expansion of hydrogen refueling stations in urban areas, and safety measures should be considered. To lower the risk of hydrogen refueling stations, this study applied the passive and active independent protection layers (IPLs) of LOPA (Layer of Protection Analysis) and confirmed that these measures significantly reduced societal risk as well as individual risk and met international standards. In particular, such measures could effectively reduce the impact of jet fire in dispensers and tube trailers that had a high risk. Measures employing both IPL types were efficient in meeting international standard criteria; however, passive IPLs were found to have a greater risk reduction effect than active IPLs. The combination of RISKCURVES and LOPA is an appropriate risk assessment method that can reduce work time and mitigate risks through protective measures compared to existing risk assessment methods. This method can be applied to risk assessment and risk mitigation not only for hydrogen facilities, but also for hazardous materials with high fire or explosion risk.

Transient Structural Analysis of a Skid Mounted on a Hydrogen Tube Trailer under Shock and Vibration Induced by Road Irregularities

Due to environmental pollution and depletion of fossil fuels, hydrogen is becoming an increasingly practical, clean and environmentally friendly option for transportation and energy storage among all green alternative energy sources introduced. Hydrogen storage and delivery is expensive because of the lower energy density per unit volume as compared with conventional fossil fuels. Hence, hydrogen is usually stored in a gaseous state and delivered via tube trailers or pipelines. In this study, a transient structural analysis of a skid structure mounted on a hydrogen tube trailer was performed under shock load induced by road irregularities. The dynamics of the driving trailer according to the unevenness of the road surface were obtained through multibody dynamic simulations considering the full car model equipped with 64 hydrogen tubes. The transient structural analysis of the tube skid was performed by considering the resulting acceleration values as constraints. Through the sequential simulations, we evaluated the structural safety of the designed tube skid mounted on a trailer during hydrogen transport.

Optimal Stochastic Operation of Integrated Electric Power and Renewable Energy With Vehicle-Based Hydrogen Energy System

The renewable energy-based hydrogen production can lead to the integrated electric power and hydrogen system (IPHS) and offer a pathway to a sustainable energy utilization. Hydrogen is mainly transported via hydrogen tube trailers (HTs), making the hydrogen energy system (HES) operation quite different from those of other energy technologies. This paper proposes an optimal IPHS operation strategy which utilizes HT for transportation. The proposed strategy coordinates hydrogen generation, transportation, and storage stages considering constrained operations of electric power system (EPS), transportation system, and variable renewable energy. The proposed solution method is based on the alternating direction method of multipliers (ADMM) in which HES and EPS constraints are managed individually and the respective solutions are coordinated accordingly. The case studies using the modified IEEE-RTS79 have verified the validity of the proposed IPHS model and its solution method and confirmed the necessity of considering HES in enhancing the EPS operation. The synergies between EPS and HES are studied via numerical examples and the impact of the flexibilities in hydrogen generation, transportation and demand are highlighted.

Risk Assessment of Tube Trailer Leaks at Hydrogen Charging Station

Risk Assessment of Tube Trailer Leaks at Hydrogen Charging Station

Comparative global warming impact and NOX emissions of conventional and hydrogen automotive propulsion systems

With the rise of cleaner technologies for transport and the emergence of H2 as a fuel, most of the emissions in the well-to-wheel process are shifting towards the energy carrier production (fuel or electricity). The objective of this study is to perform a simplified cradle-to-grave Life Cycle Assessment (LCA) that compares the greenhouse gases (GHG) and NOX emissions of H2, electric and conventional technologies for the automotive sector in Europe and to devise the optimum strategy of vehicle fleet renewal to reduce the emissions. In this study the effect of water as GHG was considered and, unless other studies, the current European energy mix and that meeting the objectives for 2050 were considered (while technology level was kept constant) since H2 from electrolysis and electric vehicles’ well-to-wheel emissions are sensitive to the energy mix. To estimate the emissions, the fuel, vehicle production and operation cycles were considered independently for each technology and then put together. For H2, the best production and distribution strategy was steam methane reforming (SMR) with CO2 sequestration for GHG-100 gases and without capturing CO2 for NOX, both with central plant production and tube trailer transport. Fuel cell vehicles (FCV) with optimum H2 production always produce the lowest GHG-100 emissions and slightly higher NOX than battery electric vehicles (BEV) in the EU 2050 scenario. In contrast, HICEV would need to reach a fuel consumption of around 30 kWh/100 km to be competitive in emissions against BEV, for that, direct injection (DI) combined with a range extender (REx) hybrid architecture is the recommended powerplant concept. Finally, the optimum strategy to reduce emissions that Europe could follow is presented for the short, mid and long term.

Technical and Economic Analysis of One-Stop Charging Stations for Battery and Fuel Cell EV with Renewable Energy Sources

Currently, most of the vehicles make use of fossil fuels for operations, resulting in one of the largest sources of carbon dioxide emissions. The need to cut our dependency on these fossil fuels has led to an increased use of renewable energy sources (RESs) for mobility purposes. A technical and economic analysis of a one-stop charging station for battery electric vehicles (BEV) and fuel cell electric vehicles (FCEV) is investigated in this paper. The hybrid optimization model for electric renewables (HOMER) software and the heavy-duty refueling station analysis model (HDRSAM) are used to conduct the case study for a one-stop charging station at Technical University of Denmark (DTU)-Risø campus. Using HOMER, a total of 42 charging station scenarios are analyzed by considering two systems (a grid-connected system and an off-grid connected system). For each system three different charging station designs (design A-hydrogen load; design B-an electrical load, and design C-an integrated system consisting of both hydrogen and electrical load) are set up for analysis. Furthermore, seven potential wind turbines with different capacity are selected from HOMER database for each system. Using HDRSAM, a total 18 scenarios are analyzed with variation in hydrogen delivery option, production volume, hydrogen dispensing option and hydrogen dispensing option. The optimal solution from HOMER for a lifespan of twenty-five years is integrated into design C with the grid-connected system whose cost was $986,065. For HDRSAM, the optimal solution design consists of tube trailer as hydrogen delivery with cascade dispensing option at 350 bar together with high production volume and the cost of the system was $452,148. The results from the two simulation tools are integrated and the overall cost of the one-stop charging station is achieved which was $2,833,465. The analysis demonstrated that the one-stop charging station with a grid connection is able to fulfil the charging demand cost-effectively and environmentally friendly for an integrated energy system with RESs in the investigated locations.

The simulation and analysis of leakage and explosion at a renewable hydrogen refuelling station

The number of hydrogen refuelling stations (HRSs) is steadily growing worldwide. In China, the first renewable hydrogen refuelling station has been built in Dalian for nearly 3 years. FLACS software based on computational fluid dynamics approach is used in this paper for simulation and analysis on the leakage and explosion of hydrogen storage system in this renewable hydrogen refuelling station. The effects of wind speed, leakage direction and wind direction on the consequences of the accident are analyzed. The harmful area, lethal area, the farthest harmful distance and the longest lethal distance in explosion accident of different accident scenarios are calculated. Harmful areas after explosion of different equipments in hydrogen storage system are compared. The results show that leakage accident of the 90 MPa hydrogen storage tank cause the greatest harm in hydrogen explosion. The farthest harmful distance caused by explosion is 35.7 m and the farthest lethal distance is 18.8 m in case of the same direction of wind and leakage. Moreover, it is recommended that the hydrogen tube trailer should not be parked in the hydrogen refuelling station when the amount of hydrogen is sufficient.

Life cycle cost analysis: A case study of hydrogen energy application on the Orkney Islands

Hydrogen can compensate for the intermittent nature of some renewable energy sources and encompass the options of supplying renewables to offset the use of fossil fuels. The integrating of hydrogen application into the energy system will change the current energy market. Therefore, this paper deploys the life cycle cost analysis of hydrogen production by polymer electrolyte membrane (PEM) electrolysis and applications for electricity and mobility purposes. The hydrogen production process includes electricity generated from wind turbines, PEM electrolyser, hydrogen compression, storage, and distribution by H2 truck and tube trailer. The hydrogen application process includes PEM fuel cell stacks generating electricity, a H2 refuelling station supplying hydrogen, and range extender fuel cell electric vehicles (RE-FCEVs). The cost analysis is conducted from a demonstration project of green hydrogen on a remote archipelago. The methodology of life cycle cost is employed to conduct the cost of hydrogen production and application. Five scenarios are developed to compare the cost of hydrogen applications with the conventional energy sources considering CO2 emission cost. The comparisons show the cost of using hydrogen for energy purposes is still higher than the cost of using fossil fuels. The largest contributor of the cost is the electricity consumption. In the sensitivity analysis, policy supports such as feed-in tariff (FITs) could bring completive of hydrogen with fossil fuels in current energy market.

Design Research of the Double Rupture Disc Safety Relief Device Used on the Long Tube Trailer

Safety relief device is one kind of safety accessories, which can ensure the safety of transportable pressure special equipment. As a common safety relief device for long tube trailer cylinder, rupture disc cascaded with fusible plug device was fund failure to release in time in the case of fire and abnormal action under conditions, so its safety and applicability are questionable. Double rupture disc safety device is a new kind of safety device used on the long tube trailer cylinders, compared to the traditional rupture disc cascaded with fusible plug device, which has better anti-fatigue and safety performance. However, the lack of corresponding design and test method limits the application of the double rupture disc safety device used on the long tube trailer. This paper gives a new practical design of double rupture disc safety device including structure design, verification of discharge area, and the leak detection system, to provide guidance for the engineering design and development of the double rupture disc safety relief device. Experiment verification is conducted, and the results indicate that the double rupture disc safety relief device meets the requirements of operating performance.