CNG Dispensing System Priority Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current CNG filling stations do not ensure that the first arriving customer is prioritized for filling, leading to extended fill times and inefficient utilization of storage banks.
Innovation Solution
A CNG dispensing system that uses a site controller to manage priority and fluid communication with storage tanks, ensuring that vehicle tanks are filled in a predictable order based on arrival time, using existing hardware to provide a true first-in-first-out solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple dispensers are used without priority control, then more vehicles can be served simultaneously, but the first arriving customer cannot be guaranteed to fill first and fill times are extended
Solution Approach 1:
The system assigns priority levels to vehicles based on their arrival time before the filling process begins. The controller tracks which vehicle arrived first and ensures that vehicle receives service first by managing dispenser assignment and storage bank access in advance, preventing later-arriving vehicles from delaying the first vehicle's fill time.
Solution Approach 2:
The controller continuously monitors the filling status of all vehicles and adjusts dispenser assignment and storage bank access based on real-time feedback. When a higher-priority vehicle needs service, the controller can switch dispensers or storage banks to ensure the first-arriving vehicle maintains priority, dynamically responding to changing fill conditions.
2Extent of automation
If vehicles advance through storage banks based on pressure differential, then filling is automated, but vehicles may prematurely advance off Low and Mid banks due to other vehicles, underutilizing storage
Solution Approach 1:
The system pre-establishes priority levels for vehicles based on arrival time before the filling process begins. This preliminary sorting ensures that when vehicles access storage banks, the highest-priority vehicles are guaranteed access to all storage banks (Low, Mid, High) without being displaced by later-arriving vehicles, thereby preventing premature advancement and maximizing storage utilization.
Solution Approach 2:
The system applies different access rights to different storage banks based on vehicle priority. High-priority vehicles (first arrivers) receive unrestricted access to all storage banks, while lower-priority vehicles have limited access. This differentiated access ensures that storage banks are not underutilized due to premature vehicle advancement, as priority vehicles can access any available storage capacity.
3Productivity
If flow is allowed to equalize pressure between storage and vehicle tank, then filling is efficient, but dispenser may timeout due to no flow while filling other vehicles on High bank
Solution Approach 1:
The controller assigns priority levels to vehicles based on arrival time before filling begins. This preliminary prioritization ensures that the first-arriving vehicle is guaranteed continuous access to storage banks and dispensers throughout the filling process. The system prevents dispenser timeout by ensuring that priority vehicles maintain active flow connections and can be switched between dispensers or storage banks if flow interruptions occur, while lower-priority vehicles wait until higher-priority filling is complete.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system efficiently prioritizes the filling of vehicle tanks, reducing fill times for early arrivals and optimizing the use of storage banks, thereby preventing dispenser timeouts and underutilization of lower pressure banks.
Implementation Method 1
Filling a vehicle with a gaseous fuel is done based on differential pressure. The source pressure (storage) is higher than the vehicle pressure (tank). This causes the gas to flow from the storage to the tank and equalize pressure.
Data Source
AI summary
A method of dispensing compressed natural gas (CNG) includes assigning a first priority to the filling of a first destination tank and assigning a second priority to the filling of a second destination tank. The second priority is lower than the first priority. The method also includes filling the first destination tank from a first CNG source while filling the second destination tank from a second CNG source. The second CNG source provides CNG at a lower pressure relative to the pressure at which the first CNG source provides CNG.