US20060150958A1

US20060150958A1 - Quick temperature rise air intake heater

Info

Publication number: US20060150958A1
Application number: US11/311,836
Authority: US
Inventors: Alan Gill; Jan Thimmesch; Chadwick Anderson; Scott Betcher
Original assignee: Phillips and Temro Industries Inc
Current assignee: Phillips and Temro Industries Inc
Priority date: 2003-07-28
Filing date: 2005-12-19
Publication date: 2006-07-13
Also published as: EP2395226A1; US7472695B2; WO2005012807A2; EP2395226B1; CN101069010B; EP1651911A4; CN101069010A; US20060150959A1; WO2005012807A3; EP1651911A2

Abstract

A quick temperature rise air intake heater is operable to rapidly transfer heat to air as it moves across a heating element and enters the combustion chambers of an internal combustion engine. The air heater may be energized simultaneously when the engine is cranked to provide a solution to starting internal combustion engines exposed to relatively low ambient temperatures.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of International Application No. PCT/US2004/024079, filed on Jul. 27, 2004, which claims the benefit of U.S. Provisional Application No. 60/490,456, filed on Jul. 28, 2003. The disclosures of the above applications are incorporated herein by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to air heaters for internal combustion engines and, more particularly, to quick temperature rise air intake heaters.
Automotive vehicles are used throughout the world in a variety of climates. Many of the operating climates experience ambient temperatures significantly below 40° F. during at least some portion of the day for months at a time. Typical diesel powered internal combustion engines are capable of starting using a mixture of fuel and ambient air to temperatures as low as approximately 10° F., depending on engine size and compression ratio.
Diesel engines produce power using a self-ignition process. During the diesel cycle, intake air is compressed and diesel fuel is injected into the combustion chamber. The injected fuel mixes with the compressed air, evaporates and ignites. This process occurs because the intake air heats up during compression and diesel fuel has a relatively low ignition temperature. An external ignition device such as a spark plug is not needed. However, as ambient temperatures decrease, the temperature within the combustion chamber may not be high enough to ensure proper ignition of the injected diesel fuel. Accordingly, a need to heat the air and/or ignite the fuel/air mixture arises.
Many manufacturers have addressed this issue by positioning glow plugs in the combustion chambers of the engine. Glow plugs are typically shaped as elongated tubes having external threads that engage an internally threaded port formed in the cylinder head of the engine. Depending on the ambient air temperature, the glow plugs may need to be energized for some period of time prior to attempting to start the engine. Some manufacturers have begun to develop “fast start” glow plugs in an attempt to reduce the time the glow plugs need to be energized prior to starting the engine. While glow plug technology has provided some solutions to the issues involving cold starting a diesel fueled engine, glow plugs are relatively expensive and cumbersome. Specifically, many engines require one or more glow plugs to be positioned within each combustion chamber of the engine. The cylinder head or heads of the engine must be specially machined to receive and properly position the glow plugs within the combustion chambers. Because each glow plug occupies a predetermined amount of space, valve geometry and fuel injector geometry may have to deviate from their optimum positions to accommodate the size and position of each glow plug.
Additional challenges in diesel engine technology exist due to relatively restrictive emission standards becoming law. These laws limit the content of the exhaust to a certain chemical makeup. As such, vehicle manufacturers must contend with the fact that diesel engines exposed to cold ambient temperatures typically exhibit poor combustion characteristics immediately after starting. The “cold” intake air results in poor HC emissions (sometimes referred to as white smoke) and in fact may not meet certain future standards. In any case, the white smoke is undesirable and not acceptable to many customers. Accordingly, a need in the art exists for an improved method of starting cold diesel engines and reducing the initial cold emissions from the engine.
Air intake heaters have also been used to start diesel powered engines exposed to relatively cold ambient temperatures. Depending on the ambient temperature, some air intake heaters are energized up to 30 seconds or more prior to attempting to start the engine. The air heater heats a volume of air within the air intake tube located upstream of the combustion chambers. A relatively long preheat time is sometimes required to heat the air to a warm enough temperature such that the air is still above a predetermined value once it enters the combustion chambers some distance downstream from the air intake heater. These devices have been very effective in the field. However, a need exists for a more immediate start.
A new quick temperature rise air intake heater is disclosed to address some, if not all of the previously outlined concerns relating to glow plugs and air heaters. A quick temperature rise air intake heater is operable to rapidly transfer heat to the intake air as it moves across the air heater and enters the combustion chambers.
In one embodiment, power is provided to a quick temperature air rise intake heater simultaneously as the engine is cranked. The intake air is heated as it passes over the quick temperature air rise intake heater to allow the engine to start without the use of glow plugs.
In another embodiment, a quick temperature rise air intake heater is electrically coupled to a capacitor operable to selectively increase the power supply to the heating element. The output of the heater is increased during cranking of the engine.
Another quick temperature rise air heater includes a heating element having portions movable between first and second positions. The movable portions restrict more air flow when in the first position than in the second position. Very low air flows are typical during cranking or at low engine operating speeds or loads when an air heater may more likely be in use. When the heating elements are in the second position, air flow restriction is minimized. Relatively higher air flows are present when the heater would typically not be in use.
Other quick temperature rise air intake heaters include a heating element adapted to be positioned in a heat transfer relationship with the passage of an intake housing. The heating elements may include a surface having a plurality of indentations or protrusions. The indentations or protrusions cause an air flow traveling across the heating element to become turbulent to increase heat transfer from the heating element to the air or simply provide a better heat transfer situation due to surface area in contact with the air stream.
In another embodiment, a quick temperature rise air intake heater for use in an internal combustion engine includes a heating element adapted to be positioned in a heat transfer relationship with a passage formed in an intake. The heating element has first substantially planar spaced apart portions. Each first portion has a leading edge aligned along a first plane. The heating element has second substantially planar spaced apart portions. Each second portion has a leading edge aligned along a second plane spaced apart from and substantially parallel to the first plane. Each portion of the second heating element is aligned with a gap formed between the first portions.
In another embodiment, the quick temperature rise air intake heater includes a first heating element having substantially planar portions aligned with one another. Each portion is positioned at an angle to the direction of air flow. The air heater also includes a second heating element having substantially planar portions aligned with one another. Each portion of the second heating element is positioned at a second angle to the direction of air flow.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a schematic showing a quick temperature rise air intake heater in conjunction with an exemplary engine;
FIG. 2 is a cross-sectional side view of an exemplary drop-in style air intake heater;
FIG. 3 is a perspective view depicting three alternate embodiment quick temperature rise air intake heaters coupled to an exemplary air intake manifold;
FIG. 4 is an exploded perspective view of the intake manifold and air heater assembly of FIG. 3;
FIG. 5 is a cross-sectional view taken along line 5-5 as shown in FIG. 3;
FIG. 6 is a perspective view depicting an exemplary engine head;
FIG. 7 is a partial perspective view of an alternate embodiment heating element;
FIG. 8 is an electrical schematic showing multiple heating elements and/or multiple quick temperature rise air intake heaters electrically coupled in parallel;
FIG. 9 is an electrical schematic depicting a quick temperature rise air intake heater electrically coupled with a capacitor;
FIG. 10 is a partial fragmentary perspective view of an alternate embodiment heating element having a plurality of indentations formed thereon;
FIG. 11 is a cross-sectional view of an alternate embodiment quick temperature rise air intake heater positioned within a passageway formed in an exemplary intake tube; t
FIG. 12 is a cross-sectional view showing another embodiment quick temperature rise air intake heater;
FIG. 13 is a cross-sectional view depicting another alternate embodiment quick temperature rise air intake heater;
FIG. 14 is a cross-sectional view depicting another alternate embodiment quick temperature rise air intake heater showing movable heating elements in a restricted position;
FIG. 15 is a cross-sectional view depicting the quick temperature rise air intake heater of FIG. 14 having the movable heating elements oriented at an open position;
FIG. 16 is a cross-sectional view depicting another alternate embodiment quick temperature rise air intake heater; and
FIG. 17 is a fragmentary perspective view of an alternate embodiment heating element having a plurality of upset portions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
With reference to FIG. 1, an air intake system 20 is shown in communication with an exemplary internal combustion engine 22. Internal combustion engine 22 includes a cylinder head 24 coupled to an engine block 26. Intake system 20 includes an intake housing 28 mounted to head 24. Intake housing 28 includes an inlet tube 30 having a distal end 32 in communication with a source of ambient air. Ambient air is drawn through a passageway 34 extending through intake housing 28. Intake housing 28 includes an open end 36 in communication with intake valves 37 positioned within head 24. A quick temperature rise air intake heater 40 is coupled to intake housing 28. At least a portion of air heater 40 is positioned within passageway 34 in communication with and upstream of air entering combustion chambers 38 formed within engine block 26. FIG. 1 depicts air heater 40 as a “drop-in” style heater. Alternatively, air heater 40 may be mounted entirely within intake housing 28, between intake housing 28 and head 24 or within head 24.
FIG. 2 depicts air heater 40 in greater detail as including a heating element 44 coupled to an access panel 46. Heating element 44 is positioned within an aperture 47 (FIG. 1) formed within inlet tube 30. In this manner, heating element 44 is placed in communication with air traveling through passageway 34 toward combustion chambers 38 of engine 22. Access panel 46 sealingly engages inlet tube 30 to restrict undesirable ingress of contaminants.
Air heater 40 includes a U-shaped frame 48 coupled to access panel 46. A heater subassembly 50 is coupled to frame 48. Heater subassembly 50 includes a first holder 52, a second holder 54 and heating element 44. First holder 52 includes a housing 56 preferably shaped from a stainless steel sheet. Housing 56 defines a “C”-shaped channel bounded on three sides by a side wall 58, a side wall not shown in the Figure and an end wall 62. As is shown in FIG. 2, second holder 54 is configured substantially similar to first holder 52. Therefore, second holder 54 will not be described in greater detail.
Wave springs 64 are positioned within housing 56 in engagement with end wall 62. Thermal and electrical insulators 66 are positioned within housing 56 to engage and capture springs 64 between end wall 62 and insulator 66. Wave springs 64 urge insulators away from end wall 62 and into engagement with stops 68 which extend inwardly from the side walls.
A first bolt 70 mounts a first end 72 of heating element 44 to access panel 46. Insulators are positioned between first bolt 70 and access panel 46 such that first end 72 and first bolt 70 are not electrically coupled to access panel 46. A second bolt 74 physically and electrically couples a second end 76 of heating element 44 to frame 48. Air heater 40 is operable to emit heat once current is passed through heating element 44 via an electrical path including access panel 46, frame 48, second bolt 74, heating element 44 and first bolt 70. One skilled in the art will appreciate that air heater 40 may be constructed to include two outwardly protruding terminals similar to first bolt 70 if it is desirable to not pass current through access panel 46 and frame 48. Further details regarding air intake heaters may be found in U.S. Pat. Nos. 6,073,615 and 6,031,204, which are incorporated by reference herein.
Quick temperature rise air intake heater 40 is operable to transfer a large quantity of energy per unit time to the air as it passes over heating element 44 during engine cranking. In relative terms, the quick temperature rise air intake heater 40 provides substantially higher wattage output than air heaters previously contemplated. As discussed earlier, previous air heaters were energized a relatively long period of time prior to engine cranking during a “pre-heat” phase to heat the air located in the inlet tube while the air was not flowing into the combustion chambers of the engine. Prior air intake heater operation relied on heating a large enough volume of the air trapped within the inlet tube to a higher temperature such that the heated mass of air would still contain sufficient energy to cause combustion once the air reached the combustion chamber. The quick temperature rise air intake heater 40 operates to output a much higher quantity of energy per unit time and transfer the energy to a flowing air stream. By sizing the air heater in this manner and energizing the air heater just prior to or simultaneously with engine cranking, the “pre-heat” time required before engine start is greatly reduced, if not eliminated entirely. Specifically, at least one embodiment quick temperature rise air intake heater is energized only 5 seconds or less prior to engine cranking. The heater may also be energized shortly after engine cranking begins. Operation of air intake heater 40 as described results in less total power being used per engine start because the “pre-heat” time is very short in comparison to earlier devices. Depending on the ambient air temperature and the characteristics of the specific engine to be started, air intake heater 40 may be energized after the engine has been started to assure the engine remains running.
FIGS. 3-5 depict alternate embodiment air heaters 100 positioned within outlet branches 101 of air intake housing 102. FIG. 6 depicts an engine head 104 having intake ports 106. Head 104 is adapted to be coupled to an engine block (not shown). Head 104 includes a plurality of intake valves 107 operable to selectively allow intake air passing through intake ports 106 to enter the combustion chambers of the engine. Each branch 101 of air intake housing 102 is coupled to one of intense ports 106. Air intake housing 102 includes an inlet 108 in fluid communication with each branch 101 via a passageway 110. In this manner, passageway 110 provides fresh air to the combustion chambers.
Each branch 101 of air intake housing 102 includes a flange 112. Each flange 112 includes a pair of fastener apertures 114 extending therethrough. Each flange 112 includes a substantially planar mounting surface 116 in engagement with corresponding substantially planar mounting surfaces 118 (FIG. 6) formed adjacent each intake port 106 of engine head 104. Threaded fasteners 119 are mounted to head 104 and extend through apertures 114 to couple air intake housing 102 to engine head 104. Each air heater 100 is positioned within very close proximity to one of mounting surfaces 116. Therefore, each air heater 100 is positioned within very close proximity of its corresponding intake port 106 formed within engine head 104. By positioning air heaters 100 in close proximity to intake ports 106, intake air heated by each heater 100 is required to travel only a minimal distance prior to entering a combustion chamber. Such placement of the air heaters is greatly advantageous when attempting to start an engine exposed to cold ambient temperatures. Within engines equipped with air heaters positioned a greater distance from the head intake port, more energy is transferred to the walls of the air intake housing, other components mounted to the air intake housing and the engine head. This heat transfer path results in less energy being present within the charge of air entering the combustion chambers.
Each air heater 100 includes a heating element 120 operable to emit heat when current is passed between a first end 122 and a second end 124. A first holder 126 and a second holder 128 are electrically insulated from heating element 120. First and second holders 126, 128 capture heating element 120 therebetween and provide a method of mounting heating element 120 to air intake housing 102.
Each heater 100 includes a first electrical terminal 130 and a second electrical terminal 132. The electrical terminals may be shaped as threaded fasteners partly extending or completely extending through air intake housing 102. In the embodiment shown in FIG. 3, heaters 100 are electrically coupled to one another in series via a first jumper cable 134 and a second jumper cable 136.
Each first electrical terminal 130 includes a threaded fastener 137 coupled to first end 122 of heating element 120. Threaded fastener 137 extends through an aperture 138 formed in intake housing 102. Another threaded fastener 140 is mechanically and electrically coupled to second end 124 of heating element 120. Threaded fastener 140 extends through an aperture 142 extending through air intake housing 102. A jumper plate 144 electrically interconnects threaded fastener 140 and a jumper bolt 146. Jumper bolt 146 extends through apertures 148 and 150 formed in air intake housing 102 such that the threaded end of bolt 146 forms second terminal 132.
A variety of conductive and non-conductive spacers are used to mount heaters 100 to intake housing 102 and define an electrical path through each of heating elements 120. In particular, one terminal of a power source (not shown) is coupled to terminal 130 located at the left end of FIG. 3 and another terminal of the power source is coupled to second terminal 132 located at the right side of FIG. 3. First jumper cable 134 interconnects second terminal 132 of the leftmost heater 100 to first electrical terminal 130 of the center heater 100. Second jumper cable 136 interconnects second electrical terminal 132 of the center heater 100 to first electrical terminal 130 of the rightmost heater 100. Accordingly, a series electrical path is formed.
FIG. 7 depicts an alternate embodiment quick temperature rise air intake heating element 200. Heating element 200 has a modified cross-section for providing a reduced resistance to current passing therethrough. By reducing the resistance of heating element 200, greater power output from a heater including heating element 200 will be realized from a given power supply. For example, heating element 200 is a generally serpentine shaped ribbon having cross-sectional dimensions X and Y. In one embodiment, a ribbon having a dimension X equal to 0.7 mm and a dimension of Y equal to 10 mm is contemplated. A standard heavy duty truck battery has approximately 12.6 volts available at a maximum 1125 amps. Based on these power supply parameters, it is estimated that heating element 200 will output 5000 watts. It should be noted that the various heater embodiments described not only allow for fast engine starts but the heating elements could run considerably cooler than previous designs. This has a very positive impact on the life of the heating elements as a result of the relatively low operating temperatures. Furthermore, by implementing the heater strategies outlined, alternate embodiment heating elements may be designed to heat up faster than prior art air heaters. In one example, a thinner heating element is implemented as another way of achieving fast engine starts.
The material composition as well as the geometry of the heating element may also be varied to change the resistance of the heating element to obtain a desired result such as higher wattage and/or faster heater response. In this manner, a particular customer's needs may be met. In some cases, heating elements constructed from more exotic materials are used. In other cases, materials that are known to be inexpensive are chosen. Accordingly, the heating element material may have little or considerable nickel content depending on the specific customer program requirements. Furthermore, it is contemplated that any of the heating elements described may be constructed from a Positive Temperature Coefficient (PTC) type material.
FIG. 8 depicts a circuit 300 having multiple heating elements 302 electrically coupled to one another in parallel. A battery 304 provides energy to heating elements 302. By coupling the heating elements in parallel, the circuit resistance is decreased. Accordingly, the energy output from multiple heating elements 302 is increased compared to a heater having elements connected in series.
FIG. 9 depicts a circuit 400 having an air heater 402 electrically coupled to a vehicle battery 404 and a capacitor 406. Capacitor 406 is operable to selectively supply power to the air intake heater 402. Capacitor 406 is operable to maintain the voltage supply to the air heater and deliver greater power in a short amount of time. Furthermore, use of capacitor 406 may alleviate an original equipment manufacturer's concerns of using battery power during engine cranking.
FIG. 9 also shows an optional controller 410 in communication with capacitor 406. Controller 410 is operable to optimize the capacitor power flow. Optimization of the capacitor power flow allows optimization of the wattage output from heater 402. Engine start time is greatly minimized by providing a properly heated volume of air during engine cranking.
FIG. 10 depicts a portion of an alternate embodiment heating element 500 having a dimpled external surface 502. Dimpled surface 502 includes a plurality of substantially hemispherically shaped indentations 504 spaced apart from one another. The indentations 504 and corresponding protrusions 506 cause the flow of air passing over heating element 500 to become turbulent. Turbulent air flow maximizes heat transfer from heating element 500 to the air passing thereby. The surface area is also increased further enhancing the heat transfer to the air. As previously mentioned, the engine is more likely to start if the heat content of the air/fuel mixture is above a predetermined quantity. Maximizing the heat content of the air entering the combustion cylinders increases the likelihood of engine start.
FIG. 11 depicts a quick temperature rise air intake heater 600 having a heating element 602 coupled to a frame 603. Air heater 600 is shaped to fill a substantially cylindrically-shaped space 604 formed in an intake tube 606. Many air intake tubes have passageways defining circular cross-sections. The cylindrical shapes of heating element 602 and frame 603 facilitate mounting the air heater within a number of air intake tubes. Furthermore, this heater shape may also be more conducive to positioning the heating element closer to the combustion chambers.
FIG. 12 depicts another alternate embodiment quick temperature rise air intake heater 700 having a first heating element 702 and a second heating element 704. Heating element 702 is spaced apart from heating element 704 such that air flow entering the downstream heating element 704 is substantially turbulent in nature. Heat transfer from heating element 704 to the air is more efficient within a turbulent air stream. Accordingly, this embodiment attempts to maximize the heat content of the air entering the combustion chamber.
FIG. 13 shows an air intake heater 800 having a heating element 802. Heating element 802 has a first portion 804 having substantially planar sections 806. Planar sections 806 are spaced apart from one another to define gaps 807. Each planar section 806 includes a leading edge 808 aligned along a first plane 810. A second portion 812 of heating element 802 includes substantially planar sections 814. Planar sections 814 are also spaced apart from one another. Each planar section 814 includes a leading edge 816 aligned along a second plane 818.
Intake air travels along the direction of the arrows depicted in FIG. 13. The flow of intake air is impeded by leading edges 808 of first portion 804. Air continues to travel across the width of first portion 804 where heat is transferred from heating element 802 to the air passing thereby. Leading edges 816 of second portion 812 are positioned to impede the flow of air passing between individual sections 806 of first portion 804. By positioning sections 814 of second portion 812 in line with the gaps 807 defined by sections 806 of first portion 804, a greater heat transfer efficiency is realized because the air is required to follow a circuitous path around various sections of heating element 802. It should be appreciated that while FIG. 13 depicts only two planes of leading edges, a single heating element or multiple heating elements may be arranged to provide a more convoluted path for the air to follow as it passes through air heater 800. Furthermore, FIG. 13 depicts leading edges 816 aligned along second plane 818 as being spaced apart from a plurality of trailing edges 820 of first portion 804. Other embodiments having sections 806 and sections 814 that at least partially overlap one another to form a nested or intergiditated arrangement are contemplated.
FIGS. 14 and 15 relate to another quick temperature rise air intake heater embodiment identified at reference numeral 900. Air intake heater 900 is positioned within an air intake tube 902 having a passageway 904. Air heater 900 includes a frame 906 and a plurality of movable heating elements 908. Each heating element 908 is rotatable about an axis 910 between a substantially restricted position as shown in FIG. 14 and a substantially open position as shown in FIG. 15. In the substantially restricted position of FIG. 14, each heating element 908 is rotated to at least partially close off an aperture 912 extending through air heater 900. When heating elements 908 are in the substantially restricted position, a greater quantity of air is forced into contact with the surfaces of heating elements 908. During this mode of operation, heat transfer from heating elements 908 to the air passing through aperture 912 is maximized. Accordingly, heating elements 908 are rotated to the substantially restricted position prior to an attempt to start a diesel fueled engine at relatively cold ambient temperatures. Sufficient gaps 914 exist between elements 908 while in the restricted position to allow air to pass by heating elements 908 at a flow rate required during engine cranking. This heating element position may also be maintained during low load engine operations where the air flow rates are low and very low restriction exists.
During maximum engine load conditions, heating elements 908 are rotated to the position shown in FIG. 15. In this position, each heating element 908 is substantially parallel to one another and parallel to the direction of air flow passing through aperture 912. FIG. 15 represents a heating element position where the flow through intake tube 902 is least restricted. The movable set of heating elements 908 provides the benefit of transferring a large quantity of heat to the intake air during starting while in the most restrictive position and is also operable to meet engine manufacturers' standards regarding intake air flow under maximum load conditions.
FIG. 16 depicts another quick temperature air rise intake heater embodiment at reference numeral 1000. Intake heater 1000 includes a frame 1002 coupled to an intake tube 1004. Air intake heater 1000 includes a first heating element 1005 and a second heating element 1006 positioned in heat transfer relationship with air passing through a passageway 1008 extending through intake tube 1004. First heating element 1005 includes a plurality of spaced apart portions 1010 positioned at an angle to the direction of air flow passing through an aperture 1012 extending through air heater 1000. First heating element 1005 disrupts the flow of air through aperture 1012 and transfers heat to air passing thereby.
Second heating element 1006 includes a plurality of spaced apart portions 1014 fixed to frame 1002. Portions 1014 are positioned at a different angle than portions 1010 relative to the flow of intake air. Portions 1014 are positioned to maximize the transfer of energy to air passing through aperture 1012. The combination effect of the positioning of first heating element 1005 and second heating element 1006 is taken into account to assure that a minimum flow rate of air through intake tube 1004 may be met during a maximum engine load condition. In one embodiment, an included angle between like portions of first heating element 1005 and second heating element 1006 form an angle “A” ranging between 30-120 degrees.
FIG. 17 shows a portion of an alternate embodiment heating element 1100 having a plurality of upset portions 1102 spaced apart from one another. Each upset portion 1102 is defined by a first slit 1104 and a second slit 1106 extending through the thickness of heating element 1100. Slit 1106 is positioned substantially parallel to slit 1104. A band of material 1110 positioned between slits 1106 and 1104 is mechanically deformed to protrude above a substantially planar surface 1112 of heating element 1100. Band 1110 includes an inflection point 1114 defining a first leg 1116 and a second leg 1118 of upset portions 1102. The geometry of upset portions 1102 and their spacing are configured to create a turbulent air flow conducive to greater heat transfer. Upset portions 1102, also known as turbulators, significantly increase the effectiveness of the heater to transmit heat to the air. Furthermore, by forming upset portions 1102 from the material of the heating element itself, current passes through the upset bands of material as well as the material surrounding the projections to further improve heat transfer to the air passing by heating element 1100.
The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations may be made therein without department from the spirit and scope of the invention as defined in the following claims.

Claims

1. A quick temperature rise air intake heater and control system for use in an internal combustion engine having an intake defining a passage, the air intake heater comprising:

a heating element coupled to a frame, the frame being adapted to be coupled to the intake, the heating element being adapted to be positioned in a heat transfer relationship with the passage; and

a capacitor electrically coupled to the heating element, the capacitor being operable to selectively increase the power supplied to the heating element to increase the output of the heater.

2. The air intake heater of claim 1 further including a controller operable to selectively control the supply of power from the capacitor to the heating element.

3. The air intake heater of claim 2 wherein the heating element is positioned within 5-20 cm of an intake port opening of an engine head.

4. The air intake heater of claim 3 wherein the heater is operable to output 2000-5000 watts when the capacitor is electrically discharging into the heating element.

5. A quick temperature rise air intake heater for use in an internal combustion engine having an intake defining a passage, the air intake heater comprising:

a heating element adapted to be positioned in a heat transfer relationship with the passage, the heating element having portions movable between first and second positions, said portions relatively restricting more air flow when in the first position than in the second position.

6. The air intake heater of claim 5 wherein the portions are positioned substantially parallel to the direction of air flow when in the second position.

7. The air intake heater of claim 6 wherein during engine starting the portions are in the first position to transfer a maximum amount of energy to the air passing through the air heater, the portions not restricting the very low air flows experienced during engine cranking.

8. The air intake heater of claim 5 wherein the movable portions of the heating elements may be positioned at positions between the first and second positions to vary the heat transfer to the air and the air flow restriction caused by the movable portions.

9. A quick temperature rise air intake heater for use in an internal combustion engine having an intake defining a passage, the air intake heater comprising:

a heating element adapted to be positioned in a heat transfer relationship with the passage, wherein the heating element includes a surface having a plurality of indentations formed thereon, wherein the indentations cause an air flow traveling across the heating element to become turbulent to increase heat transfer from the heating element to the air.

10. The air intake heater of claim 9 wherein the heating element has a serpentine shape.

11. A quick temperature rise air intake heater for use in an internal combustion engine having an intake defining a passage, the air intake heater comprising:

a heating element adapted to be positioned in a heat transfer relationship with the passage, wherein the heating element includes a surface having a plurality of indentations formed thereon, wherein the indentations cause an air flow traveling across the heating element to contact additional heating element surface area and increase heat transfer from the heating element to the air.

12. The air intake heater of claim 11 wherein the heating element has a serpentine shape.

13. A quick temperature rise air intake heater for use in an internal combustion engine having an intake defining a passage, the air intake heater comprising:

a heating element adapted to be positioned in a heat transfer relationship with the passage, wherein the heating element includes a surface having a plurality of protrusions formed thereon, wherein the protrusions cause an air flow traveling across the heating element to become turbulent to increase heat transfer from the heating element to the air.

14. The air intake heater of claim 13 wherein the protrusions include webs of heating element material partially separated from adjacent heating element material, wherein the webs are deformed to protrude from a surface of the adjacent heating element material.

15. The air intake heater of claim 14 wherein the webs are defined by two substantially parallel slits extending through the heating element.

16. The air intake heater of claim 13 wherein current flows through the protrusions during energization of the heating element.

17. A quick temperature rise air intake heater for use in an internal combustion engine having an intake defining a passage having a direction of air flow, the air intake heater comprising:

first and second heating elements coupled to a frame, the frame being adapted to be coupled to the intake, the heating elements being adapted to be positioned in a heat transfer relationship with the passage, the first heating element having substantially planar portions aligned with one another, at least two of the planar portions being positioned at an angle to the direction of air flow, the second heating element having substantially planar portions aligned with one another, at least two of the planar portions of the second heating element being positioned at a second angle to the direction of air flow.

18. The air intake heater of claim 17 wherein the first heating element portions are positioned at an angle to deflect the flow in a first direction substantially perpendicular to the direction of air flow.

19. The air intake heater of claim 18 wherein the second heating element portions are positioned at an angle to deflect the flow in a direction opposite the first direction.

20. The air intake heater of claim 19 wherein the first and second heating elements are serpentine in shape.

21. The air intake heater of claim 17 wherein at least one planar portion of the first heating element forms an angle with at least one planar portion of the second heating element ranging between thirty and one hundred and twenty degrees.

22. A quick temperature rise air intake heater for use in an internal combustion engine having an intake defining a passage having a direction of air flow, the air intake heater comprising:

a heating element adapted to be positioned in a heat transfer relationship with the passage, the heating element having first substantially planar spaced apart portions, each first portion having a leading edge aligned along a first plane, the heating element having second substantially planar spaced apart portions, each second portion having a leading edge aligned along a second plane spaced apart from and substantially parallel to the first plane, each portion of the heating element being aligned with a gap formed between the first portions.

23. The air intake heater of claim 22 wherein the first and second heating element portions are oriented substantially parallel to one another and parallel to the direction of air flow.

24. The air intake heater of claim 23 wherein the heating element is serpentine in shape.

25. A method of cold starting a diesel fueled internal combustion engine having a quick temperature rise air intake heater, the method comprising:

determining the ambient air temperature;

simultaneously energizing the quick temperature rise air intake heater and cranking the engine if the ambient air temperature is below a predetermined value; and

heating intake air as it passes over the quick temperature rise air intake heater until the engine starts.

26. The method of claim 25 further including electrically connecting a capacitor to the air intake heater to selectively increase the power supplied to the heater during engine cranking.

27. The method of claim 26 further including outputting a signal indicative of the ambient air temperature to a controller and selectively controlling the output of the capacitor during engine cranking.

28. The method of claim 25 further including outputting at least 2000 watts from the heater during engine cranking.

29. The method of claim 25 further including positioning the air intake heater at the entrance to the intake port.

30. The method of claim 25 further including electrically connecting a plurality of heating elements in parallel.

31. The method of claim 25 further including positioning a cylindrically shaped outer surface of the air heater within a cylindrically shaped aperture upstream of the intake valves of the engine.

32. The method of claim 25 wherein the predetermined ambient air temperature is 10° F.

33. The method of claim 25 further including spacing apart a plurality of indentations on a surface of a heating element to cause turbulent air flow and increase the heat transfer from the heating element to the air passing over the heating element.

34. The method of claim 25 further including positioning a first heating element at a first position and a second heating element at a position downstream from said first position, said second heating element being spaced apart from said first heating element a distance great enough to place said second heating element in a substantially turbulent flow.

35. A method of cold starting a diesel fueled internal combustion engine having a quick temperature rise air intake heater, the method comprising:

determining the ambient air temperature;

energizing the quick temperature rise air intake heater if the ambient air temperature is below a predetermined value;

starting the engine within 5 seconds of heater initial energization; and

heating intake air as it passes over the quick temperature rise air intake heater to achieve a start.

36. The method of claim 35 further including outputting at least 2000 watts from the heater during engine cranking.

37. The method of claim 35 continuing to energize the quick temperature rise air intake heater after the engine has started.