Search

Emerging hydrogen energy storage technologies present a potential opportunity to increase the flexibility and resiliency of the integrated power and transportation system with ultra-high penetration of renewable energy. This paper studies a conceptual integrated energy-mobility system (IEMS) based on renewable-to-hydrogen stations (RHSs) and tank truck fleets. In an RHS, the renewables power the grid while also charge a hydrogen energy storage unit that can perform power-to-hydrogen (P2H) and hydrogen-to-power (H2P) operations. Besides, using tank truck fleets, the RHS will distribute its surplus hydrogen products to local consumers, e.g., refueling stations serving hydrogen fuel cell vehicles. The operation framework of the IEMS is analyzed, and some preprocessing technologies are developed to reduce modeling complexity, then, a joint optimal scheduling model, involving renewable generation contract, P2H, and H2P of the station, hydrogen product demands of the local consumers, vehicle routing problem of the truck fleets, is established. Afterward, the formulated problem is solved by a heuristic method based on the Exhaustive Search and Genetic Algorithm. Numerical results verify the effectiveness of the joint optimal scheduling model and illustrate that the IEMS has the potentials to promote hydrogen-integrated transportation and power systems.

In this study, the liquefied petroleum gas (LPG) accident in Wenling, Zhejiang Province, China, on June 13, 2020, was analyzed and simulated. An LPG tank truck overturned and collided with the concrete guardrail; the subsequent explosion of the tank released 25.36 t LPG. Shortly afterward, the LPG tank was shot into the air, and the gas cloud ignited, thereby triggering a fire and vapor cloud explosion (VCE). This accident killed 20 people, injured 175 people, and caused significant property loss. The accident timeline was established based on multiple accident images, and the accident process was discussed in detail. The distribution of tank debris, evaporation and spreading of the LPG pool, dispersion of the LPG gas cloud, and VCE were simulated with the EFFECTS and ALOHA software. The images of the accident scene helped to determine and analyze the accident process. In the particular case in which a tank is shot into the air with a continuous two-phase jet, the actual flight distance of the tank is much greater than the prediction of the debris distribution model. The gas cloud distribution simulated with the SLAB model approximately corresponds to a major part of the severely damaged zone. In this accident, the TNO multi-energy method and ALOHA provide relatively consistent predictions with the actual building damage distribution when models use a specific confined explosive mass.

Influenced by lateral liquid sloshing in partially filled tanks, tank vehicles are apt to encounter with rollover accidents. Due to its strong nonlinearity and loading state uncertainty, it has great challenges in tank vehicle active control. Based on the model-free adaptive control (MFAC) theory, the roll stability control problem of tank trucks with different tank shapes and liquid fill percentages is explored. First, tank trucks equipped with cylinder or elliptical cylinder tanks are modelled, and vehicle dynamics is analyzed. This dynamic model is used to provide I/O data in the controlled system. Next, the control objective of tank vehicle rollover stabilization is analyzed and the controlled variable is selected. Subsequently, differential braking and active front steering controller are designed by MFAC algorithm. Finally, the effectiveness of the designed controllers is verified by simulation, and difference between the controllers is analyzed. The controller designed by MFAC algorithm is proven to be adaptive to vehicle loading and driving states. The controlled system has great robustness.

This study proposes an integrated approach to plan tank-truck shipments of hazardous materials in intercity road networks. Considering the conventional damage and the diffusion of volatile toxicants separately, we define the risk indicators of tank-truck hazardous materials transportation. Moreover, we study the network consisting of a local distribution sub-network and a long-distance transportation sub-network. They can be implemented by a capacitated p-hub location model and a bi-level programming model. Furthermore, an exact algorithm and an improved imperialist competitive algorithm are developed to solve the bi-level programming model, respectively. Besides, there is a case study completed in a local region of East China. The numerical results demonstrate the research advantages in method innovation and engineering operation.

Systemic numerical studies have been carried out to analyze the influence of the main traffic parameters at the moment of braking of a regular column of tank trucks in order to determine the maximum values of the dynamic impact on transport facilities. A refined design scheme of a unified oscillatory system, a mathematical model developed by the authors, and a unified numerical algorithm for nonlinear oscillations are used. The computer complex in the Simulink simulation package for dynamic and event-driven systems of the MATLAB system was adapted to solve the posed problem on the basis of expert models developed earlier by the authors. A parametric analysis of the impact level of tank truck columns on transport facilities when changing the mode of movement is carried out according to the results of computational experiments. When simulating the passage of a vehicle column, the parameters of the movement of the column, the position of the first vehicle on the transport facility at the time of the start of braking, as well as the characteristics of an individual tanker in the column were varied. The degree of influence of each parameter is determined, and their combinations in which there is a danger of excess dynamic impact of a moving load on transport facilities are identified. The expediency of separating such columns into a special class of moving load and the need to amend the regulatory documents are shown.

Introduction: Cargo Tank Trucks (CTTs) are a primary surface transportation carrier of hazardous materials (hazmat) in the United States and CTT rollover crashes are the leading cause of injuries and fatalities from hazmat transportation incidents. CTTs are susceptible to rollover crashes because of their size, distribution of weight, a higher center of gravity, and the surging and sloshing of liquid cargo during transportation. This study identified and quantified the effects of various factors on the probability of rollover and release of hazmat in traffic crashes where a CTT was involved. Method: Bayesian Model Averaging (BMA)-based logistic regression models were estimated with rollover and hazmat release as the binary response variables, and crash, truck, roadway, environment, and driver characteristics as the explanatory variables. 2010–2016 police-reported CTT-involved crash data from Nebraska and Kansas was utilized. Receiver Operating Characteristic (ROC) curves confirmed appropriateness of the modeling approach for inference and prediction on the crash dataset. Results: CTTs are more likely to rollover in crashes while turning and changing lanes relative to going straight; side impacts (side collisions) and severe crosswinds increased the likelihood of rollovers; tractor and semi-trailer body style decreased the probability of rollover, while truck tractors are more prone to rollovers; collisions with fixed objects and higher posted speeds increased the rollover probability; rollovers and intersection crash locations increased the likelihood of hazmat release. Conclusions: The findings can assist stakeholders (policy-makers, private shippers, and CTT drivers) in restricting CTTs’ operations for safety; scheduling, routing, and fleet planning; and low-level decision-making (e.g., emergency stopping or local routing). Practical Applications: This study identified and quantified the effects of different factors on the conditional probability of rollover and release of hazmat in CTT-involved crashes. The findings may assist stakeholders in decision-making towards safe operations of CTTs for transportation of hazmat.