Patent Publication Number: US-9428333-B2

Title: Compressed natural gas vehicle apparatus and method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This patent application is a divisional of U.S. patent application Ser. No. 13/414,631, filed Mar. 7, 2012, which claims priority under 35 U.S.C. §111 to U.S. Provisional Patent Application No. 61/450,027, filed Mar. 7, 2011, which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention generally relates to compressed natural gas (CNG) powered vehicles, e.g., refuse route vehicles such as waste collection, waste transfer, and recycling vehicles. More particularly, the present invention relates to installation of CNG cylinders in order to improve safety, maintenance, operation, reduce aerodynamic drag and fuel consumption of a vehicle. 
     BACKGROUND 
     Conventional refuse route vehicles, which are mostly operated with diesel fuel, are one of the most inefficient vehicles on the road. This vehicle type has the additional economic detriment that diesel fuel is primarily produced from imported foreign oil. During operation, the vehicles are used to pickup household and commercial trash and recyclables across communities, which leave behind some air pollutants (e.g., SO x , NO x , and VOCs) and soot while generating as much as 100 decibels of noise. 
     Refuse route vehicles that operate on natural gas rather than diesel fuel can have quality of life benefits and benefit vehicle fleet operators. There is also an economic benefit to using natural gas, as use of the primarily domestically produced natural gas increases the nation&#39;s energy security. Since natural gas is plentiful within the U.S., it is not only less expensive than diesel fuel, but also reduces the threat of an oil price spike or supply disruptions. Based on U.S. Environmental Protection Agency (EPA) and Department of Energy (DOE) studies, CNG trucks produce 75% lower carbon monoxide emissions, 49% lower nitrogen oxides emissions, 24% lower greenhouse gas emissions, and 95% lower particulate matter emissions than similarly sized diesel trucks. 1  Natural gas fueled refuse vehicles also produce approximately 70-80 less decibels inside the vehicle. 2    1  http://www.afdc.energy.gov/afdc/vehicles/emissions_natural_gas.html 2  Baruch College with Council on the Environment of New York City, “Neighborhood Noise and its Consequences,” December 2004 
     There are several benefits of using natural gas to power vehicles. For example, natural gas costs are approximately one-third lower than that of gasoline. Natural gas prices have exhibited significant stability compared to oil prices, which makes it easier to plan accurately for long-term costs. 
     CNG powered refuse route vehicles are currently operational. Typically, these vehicles use 4 or 6 high pressure cylinders, approximately 3,600 psig, to store natural gas. As shown in  FIG. 1  for a front load vehicle, vehicle  100  comprises cylinders or tanks  101  that are securely installed at the back end on the roof  102  of the body  107 , about 13-13.5 ft from the ground. Cab protector  105  is attached to the front face  109  of body  107 . Gas pipelines (not shown), which deliver fuel to the engine and refueling tanks (not shown), and electric wires (not shown) for valve control are routed from the cylinders to the location of the vehicle&#39;s engines. 
       FIG. 1A  shows an alternative prior art design. Rear loading vehicle  150  includes rear loading mechanism  152  and tank enclosure  151 . Notably, a plurality of CNG tanks (not shown) is installed inside of enclosure  151 . Tank enclosure  151  is coupled to front face  154  of vehicle body  155 . Due to the height of enclosure  151 , which is parallel to roofline  153  of vehicle, additional aerodynamic drag is created when the vehicle is in motion. This reduces overall fuel efficiency in the operation of vehicle  150 . 
       FIG. 1B  demonstrates the conventional tank enclosure  151  shown in  FIG. 1A . CNG tanks (now shown) are configured to fit inside of enclosure  151 . As shown in  FIG. 1A , the tank enclosure can be coupled, e.g., bolted, welded, etc., to the front face  154  of vehicle body. Brackets  156  are used to attach enclosure  151  to the body  155   b  of a refuse vehicle. Access panels  158  are used to allow access to valve mechanisms disposed on one end of each CNG tank. Knob  158   a  is manipulated to open panels  158 . Hinges  158   b  are used to allow panel  158  to open and close. Vehicle operators may manually manipulate valve mechanism to turn on or off the flow of natural gas from the CNG tanks. 
     Once installed, the rear portion  159   a  of the tank enclosure  151  faces the front face  154  of body  155   b  of vehicle. The front portion  159   c  is configured to fit above vehicle cab  155   a . In this conventional design, tank enclosure  151  prevents falling debris from entering CNG tank apparatus. Entry of debris into CNG tank apparatus could damage or dislodge CNG tanks. A damaged or dislodged tank could lead to catastrophic failure such as vehicle fire. However, as vehicle travels in a forward direction, a strong wind vortex will be formed in the L-shaped space of  159   c . Consequently leads to an increased drag resistance so the fuel efficiency is reduced. 
     There are several detriments associated with this prior art design of CNG tank installations. As the tanks  101  are installed on the roof top  102  of vehicle  100 , the high elevation of vehicle  100  increases aerodynamic drag, which increases fuel consumption and creates potentially serious safety concerns. For example, as vehicles travel through communities, under bridges, elevated walkways, trees, telephone and electric power lines, the CNG tanks are exposed to possible contact with these objects. Furthermore, as refuse is picked up by front loader mechanism  104  and raised over cab  108 , cap  105 , sliding door  106  is slid toward the rear of vehicle  100  and refuse is placed into the body portion  107  of the vehicle. This process often allows waste to wipe into tank area  101 . Also, as the engine (not shown) is located near the rear of the cab  108  and the tanks are located on the rear top portion of the body  107 , a long and complex gas pipeline route and electric wires are required to run on both sides of the truck for delivery of natural gas, refueling and electrical connection. This complexity greatly increases the cost of installation, maintenance and service. 
     Consequently, there is a need for a method to design, install and operate the CNG tanks on refuse route vehicles that would prevent the shortcomings of previous designs. 
     SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION 
     Method and apparatus for improving compressed natural gas powered vehicles are described. 
     According to an exemplary aspect, a method of installing a plurality of compressed natural gas tanks to a vehicle is provided. The method comprises providing an apparatus to house a plurality of CNG tanks, installing the plurality of CNG tanks in the interior of the apparatus, installing the apparatus on a front portion of the body of the vehicle and below the roof line of the vehicle, connecting the CNG tanks to the engine of the vehicle, and connecting the CNG tanks to a controller of the vehicle. 
     In the preceding embodiment, the apparatus is configured to couple to a tank enclosure apparatus of the vehicle. 
     In the preceding embodiments, the tank enclosure apparatus is configured to attach to the body of the vehicle. 
     In any of the preceding embodiments, the plurality of CNG tanks comprises at least one tank but typically three tanks or more. 
     In any of the preceding embodiments, gas from the plurality of CNG tanks is transported to the engine of the vehicle via at least one pipeline. 
     In any of the preceding embodiments, providing an electrical connection between the plurality of CNG tanks and a control mechanism of the vehicle. 
     In any of the preceding embodiments, installing the apparatus proximate the engine of the vehicle. 
     In any of the preceding embodiments, installing the apparatus proximate the control mechanism of the vehicle. 
     In any of the preceding embodiments, using a manifold device to transfer natural gas from the CNG tanks. 
     According to an exemplary embodiment, a compressed natural gas tank apparatus configured to house at least one CNG tank is provided. The apparatus is configured such that it can be attached to the body of a vehicle. The apparatus is also configured to be retrofitted to a previously installed cab protector, attached to the body of a CNG powered vehicle. 
     In the preceding embodiment, the apparatus comprises metal components. 
     In any of the preceding embodiments, the apparatus is configured to be attached to a manifold device. 
     In the preceding embodiment, the manifold device is configured to transfer natural gas from the at least one CNG tank to the engine of the CNG powered vehicle. 
     In any of the preceding embodiments, the at least one CNG tank is rated at least 21 diesel gallon equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is described with reference to the following figures, which are provided for the purpose of illustration only, the full scope of the invention being set forth in the claims that follow. 
         FIG. 1  illustrates a conventional CNG front loading refuse route vehicle; 
         FIG. 1A  illustrates a conventional CNG rear loading refuse route vehicle; 
         FIG. 1B  illustrates a tank enclosure/tank apparatus of a conventional real loading refuse route vehicle; 
         FIG. 2  is a schematic diagram of a CNG front loading refuse route vehicle in accordance with an exemplary aspect of the invention; 
         FIG. 3  is a schematic diagram of an alternative embodiment of a CNG front loading refuse route vehicle demonstrating a rearward configuration of the vehicle body; 
         FIG. 4  is an embodiment of a CNG tank apparatus in accordance with an exemplary aspect of the invention; 
         FIG. 4A  is an alternative embodiment of a CNG tank apparatus in accordance with an exemplary aspect of the invention; and 
         FIGS. 5A-F  are embodiments of a front loading vehicle in accordance with exemplary aspects of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY, NON-LIMITING EMBODIMENTS OF THE INVENTION 
     Exemplary embodiments of the present invention provide a CNG tank installation design and method. The use of the design provides an economic benefit as the components used are easier to manufacture and the installation procedure is less complex. Additionally, exemplary embodiments of the present invention provide for a more cost effective operation of a CNG vehicle. One or more embodiments of the invention can also be used on any other suitable battery cells beyond those described herein. 
       FIG. 2  illustrates a CNG vehicle according to exemplary aspects of the present invention. As shown in  FIG. 2 , vehicle  200  has a CNG tank installation  203  mounted behind cab  202 . The location of the tank assembly  203  is between the cab  202  and the vehicle main body  208 , with its top surface below the vehicle roofline  209 . The feature of this design increases vehicle fuel efficiency as aerodynamic drag is reduced when compared to prior designs where tanks were installed on the roof of a vehicle in case of a front loading vehicle. Or, in the case of rear or side loading vehicles where tanks are installed in a configuration parallel to the roof line of the vehicle, aerodynamic drag is similarly not reduced. In operation, front loading mechanism  201  is used to pick up a refuse container and move it to a rearward portion of vehicle  200 . Door  207  opens and the refuse is placed inside body  208  of vehicle  200 . The location of tank assembly  203 , which is below the roof line  209  of vehicle  200 , allows enough clearance for the refuse container (not shown) to pass tank assembly without refuse entering tank assembly. The location of tank assembly  203  prevents the possibility of the CNG tanks being damaged as the vehicle travels under bridges, tree branches, utility grid and telephone wires, and other obstacles that may be contacted during a typical refuse vehicle route. One of ordinary skill in the art would appreciate that the location of assembly  203  allows for more convenient pre and post trip driver inspection of vehicle, which is required by the U.S. Department of Transportation. In contrast to prior vehicle designs, the driver, according to the present design, is not required to climb to the top of vehicle in order to inspect CNG tanks, which results in less exposure to falls from the vehicle by the driver. 
     Furthermore, the location of the CNG tank apparatus  203 , i.e., below the roof line of vehicle  200  and between the cab  202  and the vehicle body  208 , reduces overall body aerodynamic drag. Vehicles configured according to the present invention demonstrate improved fuel efficiency in accordance with the installation location of tank apparatus  203 . Hydraulic components  205 , which control and manipulate front loading mechanism  201 , is located under vehicle  200 . In conventional designs, the hydraulic assembly is located between the cab and body of vehicle. Due to the installation of assembly  203 , components  205  is located under vehicle  200 . Hydraulic lines  206  are attached to assembly  205  (not shown) on one end and mechanism  201  on opposite end. 
     Engine (not shown) and electrical wires (not shown) are located in relatively close proximity to tank installation  203 . This reduces the complexity of the installation of gas pipeline and electric wires routed to engine (not shown) from tanks  204  in assembly  203 , which provides an ease of installation, maintenance and service. Tank installation  203  is installed on the front face  210  of the vehicle body  209  such that the pipelines and electric wires are limited to the front portion of the body of the vehicle. For example, the pipelines and electric wire may be located contact the body  208  of vehicle only on the front face  210  right below tank installation. The decreased piping running between the engine and tanks  204  provides less exposure to the driver when fueling the refuse vehicle. The risk of gas leakage is also minimized due to the shorter piping used in accordance with exemplary embodiments of the present invention. 
     CNG tanks  204  can be larger in diameter than tanks used on conventional CNG vehicles. As shown in  FIG. 2 , this allows for 3 tanks to be used. Notably, in an alternative embodiment, 5 CNG tanks may be used according to an exemplary embodiment of the present invention. In prior art systems, CNG vehicles typically required 5 tanks, which required more components and potentially increased operating costs. In contrast to conventional tanks, compressed natural gas tanks manufactured according to exemplary embodiments of the present invention may achieve a 65-70 Diesel Gallon Equivalents (DGE) rating. Conventional compressed natural gas tanks are typically rated at only 15 DGE. One of ordinary skill in the art would appreciate that the higher DGE rating of the present invention would enable an operator to operate a vehicle for longer distances and time without the hassle of having to replace or replenish depleted tanks. 
     It should be appreciated that as the CNG tanks are mounted within the truck envelope, i.e., below the roof line of vehicle  200 , there is less risk of damage to the truck or CNG tank apparatus  203  in the event of a roll over accident. One of ordinary skill in the art would appreciate that exemplary embodiments of the present invention present less risk to the driver and surrounding motorist, as the tank apparatus is less likely to be damaged and release gas in an accident. In contrast, prior art designs where the tanks are mounted atop the roof of a vehicle are more likely to break off, causing damage and release of gas in an accident. 
     In addition to CNG tanks  204 , tank apparatus  203  also includes a gas pipeline (not shown) attached to each tank. The pipeline is used to deliver natural gas to the engine of vehicle  200 . Each of the pipelines attached to the tanks may optionally be coupled to a manifold device (not shown). The manifold device is configured to allow a single pipeline to be attached to the exterior of apparatus  203  and deliver natural gas required by engine  205 . The single pipeline attached to apparatus  203 , which would be attached to face  210 , could transfer natural gas from one or more of tanks  204 , individually or collectively. 
     CNG tanks  204  may optionally be manipulated by electrical controller mechanism (not shown). In this embodiment, electrical controller would transmit signals to tanks  204  via electrical wires  206 . The controller could be used to shut off one or more of tanks  204 , or control the rate at which natural gas is delivered to vehicle engine  205 . Alternatively, tanks  204  may be individually shut off by manual manipulation of valve mechanisms  211 . 
       FIG. 3  shows an alternative embodiment of a front loading refuse route vehicle  300 . Body  301  is moved more rearward on frame  306  of vehicle  300 . In this exemplary embodiment, body is move rearward 1.5 inches; however, one of ordinary skill in the art would appreciate that the placement of the body along vehicle chassis can only be done such that it allows the unobstructed operation of front loading mechanism  304 . In this alternative embodiment, body  301  is moved rearward in an effort to more evenly distribute weight along the frame of vehicle  300 . Notably, the movement of front loading mechanism is not obstructed when emptying the contents of a refuse receptacle into the body  301  of vehicle  300 . CNG tank apparatus  303  is configured to fit with cab protector  302 . According to exemplary embodiments of the present invention, apparatus  303  is configured to be retrofitted with conventional cab protectors. Thus, no further operator investment is necessary in order to implement CNG tank design and method according to the present invention. Front loader mechanism is designed to pick up a refuse receptacle (not shown), move it rearward over tank apparatus  303 , and place contents of receptacle into the vehicle&#39;s body  301 . 
       FIG. 4  shows CNG tank apparatus  400 . As shown, apparatus  400  comprises a compartment to house a plurality of CNG tanks  402 . In an exemplary embodiment apparatus  400  may be made of a various materials. For example, apparatus  400  can comprise metals such as steel aluminum, magnesium or composite materials. However, it should be noted that any material, suitable to achieve the goals of the present invention, may be used. In this embodiment, apparatus  400  is configured to house three CNG tanks. However, as previously noted, CNG tank apparatus  400  can be configured to house a desired number of tanks. Accordingly, it should be appreciated that the vehicle is able to travel for longer distances with the use of additional CNG tanks. 
     As shown, frame structure  401  consists of a plurality of members that configures such that it houses CNG tanks  402 . Canisters  402  are disposed longitudinally within structure  401 . Valve mechanisms (not shown) provide for the flow of compressed natural gas to be manually and or electronically manipulated, e.g., turned on or off. Also, pipe lines (not shown) are connected to CNG tanks in order to deliver natural gas to the associated vehicle. Controller mechanism determines the rate at which natural gas flows from the CNG tanks. Accordingly, natural gas is delivered to the engine of the vehicle, which propels the vehicle. Alternatively, an electronic controller mechanism may be used to determine which of CNG tanks to power the vehicle, or the rate at which the compressed natural gas is delivered to the engine of the vehicle. This allows the user to conserve gas in a selected number of CNG tanks for emergency situations, e.g., depletion of natural gas from the operational CNG tank. 
     It should be appreciated that back wall  403  of frame structure is configured to attach to the front face of vehicle body. See e.g.,  210  of  FIG. 2 . Bottom portion  404  of frame structure  400  is designed to fit over vehicle cab. It should be appreciated that structure  400  can be configured to any appropriate layout and shape that would lead to minimal air resistance. According to an exemplary embodiment of the present invention, structure  401  is attached to the body of vehicle such that it is below the roofline of vehicle and behind the cab. Additionally, structure is designed such that it may be retrofitted to couple to cab liners known currently in the art. For example, the top portion  405  of structure will be mounted beneath cab liner, in hollowed portion. See e.g.,  105  of  FIG. 1 . As the frame structure may be retrofitted to the current cab liners, exemplary embodiments of the present invention allow for user implementation without the need to purchase additional components to replace existing non-CNG tank components. 
     Alternatively, as shown in  FIG. 4A , apparatus  400  may have a solid portion  406  below bottom portion  404 . Furthermore  FIG. 3  shows solid portion  406  can have a sloped configuration, in which a portion is above cab  305 , and the lowest portion is attached to the bottom portion of assembly  303 . Solid portion  406  prevents air from entering beneath tank structure and between cab  305  and body  301  as vehicle  300  travels. This provides increased fuel efficiency as aerodynamic drag created by air gathering between the cab and body of vehicle is minimized. It should be appreciated that solid portion  406  may be used in any embodiment of the present invention. 
       FIG. 5A  demonstrates a front loading refuse route vehicle designed according to exemplary embodiments of the present invention. Vehicle  500  comprises cab  502  and body  501 . Vehicle  500  is propelled by the delivery of natural gas to its engine. Natural gas is delivered to the engine from CNG tanks housed in apparatus  503 . 
     As shown in  FIG. 5B , apparatus  503 , which houses three compressed natural gas tanks (not shown), is designed to be installed between cab  502  and body  501 . More specifically, apparatus  503  is mounted to the front face  504  of body  501 . Apparatus  503  is also mounted below cab protector  505 , which serves to prevent damage to the cab  502  in the event that a refuse container is disengaged from front loading mechanism (not shown) during operation. Cab protector  505  and apparatus  503  are mounted to body  501  below roofline  501   a  of vehicle. The location of cab protector  505  and apparatus  503  decreases drag force created by vehicle  500  as it travels. The decreased drag force increases fuel efficiency. 
     It should be appreciated that previous designs of front loading refuse route vehicles installed CNG tanks on the roof of vehicle bodies, as heretofore there was not an apparatus design capable of being mounted in the limited area between the cab and body of a vehicle. Notably, a housing apparatus for prior art designs of CNG tanks would have required the vehicle body, e.g.,  501  to be moved too far rearward on vehicle chassis. Relocation of the vehicle body too far rearward would prevent normal operation of front loading mechanism, as it would not be able to clear vehicle cab when hoisting a refuse container. Additionally, relocation of the body could cause imbalance in weight distribution along the vehicle. 
       FIG. 5C  shows a more detailed depiction of tank apparatus  503  installed according to exemplary embodiments of the present invention. As shown, bottom face  507   a  sits above, but not in contact with roof  509  of cab. Also, top face (not shown) of apparatus  503  sits below and is adjacent cab liner  503 . Cab liner  503 , which is known in the art, is mounted via bolts  510  to front face  504  of vehicle body. Apparatus  503  is affixed to the front face  504  of body via bolts (not shown), or any other suitable means to attach the apparatus to the vehicle body. It should be appreciated that apparatus  503  is designed to retrofit, i.e., sit below and couple to, conventional cab liners, e.g.,  505 . Furthermore, bottom face  507   b  is designed to not obstruct rear cab window  508 . This allows vehicle operator to have an unobstructed view of the vehicle body operations. For example, the operator can look through rear window  508  to ensure that refuse loaded in body is being compacted in a normal fashion. 
       FIG. 5D  demonstrates a more detailed view of how tank apparatus  503  is configured to fit within currently used cab protector. The interior of cab protector  505  is hollow (not shown). As shown, apparatus  503  is at least partially disposed within hollowed portion of cab protector  505 . Apparatus is designed to easily fit with cab protector  505 . For example, apparatus  503  is installed to sit on interior side of lever  511 . This allows for the unobstructed movement of lever  511 , which is used to manipulate the position of the front portion  512  of cab protector  512 . In accordance with movement of lever  511 , a varying portion of the cab&#39;s roof  509  may be covered by the front portion of cab protector  512 . 
       FIGS. 5E and 5F  show an alternative embodiment of the front loading vehicle design according to present invention. Apparatus  503 ′, which is designed to fit below cab protector  505 ′, includes bottom face  507   a ′, which sits above the cab of vehicle. Apparatus  503 ′ also includes bottom face  507   b ′, which is positioned such that window  508 ′ of vehicle is not obstructed. Although apparatus  503 ′ is configured for four CNG tanks  506 ′, it should be appreciated that apparatus  503 ′ can be configured to accommodate any number of CNG tanks. Additionally,  FIG. 5F  shows a side view of the apparatus  503 ′. Notably, lift eyes  520 ′ are configured such that the entire apparatus  503 ′ may be hoisted. For example, lift eyes  520 ′ may be engaged with a lifting mechanism (not shown) to hoist apparatus  503 ′ during the manufacturing process or during service of the apparatus. Lift eyes  520 ′ may be located in each corner of top panel  525 ′. Alternatively, lift eyes  520 ′ may be located in any configuration such that the top panel  525 ′ is secured to apparatus  503 ′. One of ordinary skill in the art would appreciate that lifting eyes  520 ′ may be implemented in any apparatus configuration, regardless the number of CNG tanks housed within. 
     Although exemplary embodiments of the present invention are optimized for use on a front loading refuse vehicle, the housing apparatus may be used for a conventional rear loading vehicle. In the event that present invention&#39;s housing apparatus is used on a rear loading vehicle powered by natural gas, the existing tank apparatus/tank enclosure will first need to be removed. For example, tank enclosure  151  of the conventional rear loading vehicle shown in  FIG. 1A  would be removed from vehicle  150  prior to installation of housing apparatus, e.g.,  400  of  FIG. 4 . Apparatus  400  may then be attached to front face  154  of vehicle  150 . As discussed in other embodiments, apparatus  400  would be installed below roofline  153  and behind the cab  155   a  in order to minimize drag force during vehicle operation and thereby increase fuel efficiency. Thus, apparatus  400  would be installed in a position lower than that of tank enclosure  151  in the conventional rear loading vehicle design. 
     The above-described features may be implemented in combination with each other to provide various exemplary embodiments in accordance with the invention. 
     Although the invention has been described and illustrated in the foregoing illustrative embodiments, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the details of implementation of the invention can be made without departing from the spirit and scope of the invention, which is limited only by the claims that follow. Features of the disclosed embodiments can be combined and rearranged in various ways within the scope and spirit of the invention.