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An operation strategy known as two-tier “pressure consolidation” of delivered tube-trailers (or equivalent supply storage) has been developed to maximize the throughput at gaseous hydrogen refueling stations (HRSs) for fuel cell electric vehicles (FCEVs). The high capital costs of HRSs and the consequent high investment risk are deterring growth of the infrastructure needed to promote the deployment of FCEVs. Stations supplied by gaseous hydrogen will be necessary for FCEV deployment in both the near and long term. The two-tier pressure consolidation method enhances gaseous HRSs in the following ways: (1) reduces the capital cost compared with conventional stations, as well as those operating according to the original pressure consolidation approach described by Elgowainy et al. (2014) [1], (2) minimizes pressure cycling of HRS supply storage relative to the original pressure consolidation approach; and (3) increases use of the station's supply storage (or delivered tube-trailers) while maintaining higher state-of-charge vehicle fills. [ABSTRACT FROM AUTHOR]

We conducted a techno-economic and thermodynamic analysis of precooling units (PCUs) at hydrogen refueling stations and developed a cost-minimizing design algorithm for the PCU observing the SAE J2601 refueling protocol for T40 stations (requiring −40 ° C precooling temperature). In so doing, we identified major factors that affect PCU cost and energy use. The hydrogen precooling energy intensity depends strongly on the station utilization rate, but approaches 0.3 kWh e /kg-H 2 at full utilization. In early fuel cell electric vehicle markets where utilization of the refueling capacity is low, the overhead cooling load (to keep the heat exchanger cold at −40 °C) results in significantly high PCU energy intensity because only a small amount of hydrogen is being dispensed. We developed a parameterized precooling energy intensity prediction formula as a function of the ambient temperature and station utilization rate. We also found that the Joule-Thomson effect of the flow control device introduces a significant increase in temperature upstream of the PCU's heat exchanger (HX), which impacts the PCU design capacity. An optimal PCU (per dispenser, at 35 °C HX inlet temperature) consists of a 13-kW refrigerator and a HX with 1400 kg of thermal mass (aluminum), which currently costs $70,000 (uninstalled). The total (installed) capital and operation cost of PCU at a fully utilized hydrogen refueling station adds $0.50/kg-H 2 . [ABSTRACT FROM AUTHOR]

Reliable design and safe operation of heavy-duty hydrogen refueling stations are essential for the successful deployment of heavy-duty fuel cell electric vehicles (FCEVs). Fueling heavy-duty FCEVs is different from light-duty vehicles in terms of the dispensed hydrogen quantities and fueling rates, requiring tailored fueling station design for each vehicle class. In particular, the selection and design of the onboard hydrogen storage tank system and the fueling performance requirements influence the safe design of hydrogen fueling stations. A thermodynamic modeling and analysis are performed to evaluate the impact of various fueling parameters and boundary conditions on the fueling performance of heavy-duty FCEVs. We studied the effect of dispenser pressure ramp rate and precooling temperature, initial tank temperature and pressure, ambient temperature, and onboard storage design parameters, such as onboard storage pipe diameter and length, on the fueling rate and final vehicle state-of-charge, while observing prescribed tank pressure and temperature safety limits. An important finding was the sensitivity of the temporal fueling rate profile and the final tank state of charge to the design factors impacting pressure drop between the dispenser and vehicle tank, including onboard storage pipe diameter selection, and flow coefficients of nozzle, valves, and fittings. The fueling rate profile impacts the design and cost of the hydrogen precooling unit upstream of the dispenser. • Impact of various fueling parameters on the fueling performance of heavy-duty fuel-cell vehicles. • Pipe diameter has strong influence on pressure drop and mass flow rate. • Higher pressure ramping rate requires cooler dispenser temperatures. • Higher initial tank pressure reduces the precooling load. • Higher ambient temperature increases the precooling load. [ABSTRACT FROM AUTHOR]

The rollout of hydrogen fuel cell electric vehicles (FCEVs) requires the initial deployment of an adequate network of hydrogen refueling stations (HRSs). Such deployment has proven to be challenging because of the high initial capital investment, the risk associated with such an investment, and the underutilization of HRSs in early FCEV markets. Because the compression system at an HRS represents about half of the station's initial capital cost, novel concepts that would reduce the cost of compression are needed. Argonne National Laboratory with support from the U.S. Department of Energy's (DOE) Fuel Cell Technologies Office (FCTO) has evaluated the potential for delivering hydrogen in high-pressure tube-trailers as a way of reducing HRS compression and capital costs. This paper describes a consolidation strategy for a high-pressure (250-bar) tube-trailer capable of reducing the compression cost at an HRS by about 60% and the station's initial capital investment by about 40%. The consolidation of tube-trailers at pressures higher than 250 bar (e.g., 500 bar) can offer even greater HRS cost-reduction benefits. For a typical hourly fueling-demand profile and for a given compression capacity, consolidating hydrogen within the pressure vessels of a tube-trailer can triple the station's capacity for fueling FCEVs. The high-pressure tube-trailer consolidation concept could play a major role in enabling the early, widespread deployment of HRSs because it lowers the required HRS capital investment and distributes the investment risk among the market segments of hydrogen production, delivery, and refueling. [ABSTRACT FROM AUTHOR]

Recent progress in submerged liquid hydrogen (LH 2) cryopump technology development offers improved hydrogen fueling performance at a reduced cost in medium- and heavy-duty (MDV and HDV) fuel cell vehicle refueling applications at 35 MPa pressure, compared to fueling via gas compression. In this paper, we evaluate the fueling cost associated with cryopump-based refueling stations for different MDV and HDV hydrogen demand profiles. We adapt the Heavy Duty Refueling Station Analysis Model (HDRSAM) tool to analyze the submerged cryopump case, and compare the estimated fuel dispensing costs of stations supplied with LH 2 for fueling Class 4 delivery van (MDV), public transit bus (HDV), and Class 8 truck (HDV) fleets using cryopumps relative to station designs. A sensitivity analysis around upstream costs illustrates the trade-offs associated with H 2 production from onsite electrolysis versus central LH 2 production and delivery. Our results indicate that LH 2 cryopump-based stations become more economically attractive as the total station capacity (kg dispensed per day) and hourly demand (vehicles per hour) increase. Depending on the use case, savings relative to next best options range from about 5% up to 44% in dispensed costs, with more favorable economics at larger stations with high utilization. • New submerged cryopumps offer improved performance for hydrogen refueling stations. • Economic analysis tools have been adapted to model stations with new cryopump. • Cost is mainly driven by hourly fueling demand and station daily capacity. • Liquid pump-based stations are most attractive at larger stations with high utilization. • Up to 44% reduction in dispensing cost is possible with new cryopump for heavy-duty truck stations. [ABSTRACT FROM AUTHOR]

Precooling gaseous hydrogen fuel to a cold temperature before refueling a heavy-duty (HD) hydrogen fuel cell electric vehicle (HFCEV) is essential to avoid overheating the vehicle tank, as well as achieving a high state of charge (SOC). Because a large volume of hydrogen is dispensed during each fill, the need for a shorter fill time amplifies the need to precool each load for refueling a HFCEV. Thus, the design and operation of a precooling unit (PCU), as well as the associated capital and operating costs, plays a pivotal role in any plans for heavy-duty hydrogen refueling stations. In this paper, we present a thermodynamic and technoeconomic analysis of a PCU in a gaseous hydrogen refueling station (HRS) for HD HFCEVs. By employing Argonne National Laboratory's hydrogen station cost optimization and performance evaluation (H2SCOPE) model, the refueling of 50 kg of hydrogen on-board type IV tank at ambient temperatures of 15–45 °C and varying fill rates is simulated. The required degree of precooling temperature to obtain either 100% or the maximum possible SOC is obtained from the simulation. Additionally, the simulation results demonstrate that the average flow rate of hydrogen is approximately 40% lower than the maximum flow rate during a typical fill; which motivates further evaluation of the instantaneous hydrogen mass flow rate profile and suggests the scope of improving precooling unit design. Accordingly, a hybrid strategy of precooling hydrogen has been proposed to address the cooling load by sizing the refrigeration unit for the average flow rate of hydrogen, while supplementing the above average peak hydrogen flow cooling load through thermal buffering. The combined technique enables the downsizing of the original PCU capacity by 25–40% and demonstrates a potential cost reduction of the PCU by approximately 30%, which translates to an installed cost reduction of ∼$125,000 per dispenser. • Hydrogen fill rate during refueling has a strong influence on the precooling load. • Bell-shaped profile of the fill rate advises a scope of improving precooling. • Hybrid strategy of on-demand cooling aided with partial thermal buffer is proposed. • The hybrid precooling approach downsizes the refrigerator capacity by 25–40%. • A potential reduction in the capital cost of precooling unit is 30%. [ABSTRACT FROM AUTHOR]