JP6583351B2 - Exhaust system for cabin heater - Google Patents

Description

  The present invention relates to an exhaust device for a cabin heater.

  For example, the heating of cabins such as automobile cabins and ship cabins is often performed using the heat of an engine that is a power source. However, the engine heat cannot be used to heat the cabin when the engine is stopped or immediately after the engine is started. For this reason, a cabin heater that warms the air in the cabin by the combustion heat of the fuel may be provided separately from the engine.

  When the combustion exhaust gas is directly discharged into the cabin, oxygen deficiency is caused. Therefore, as described in, for example, JP-A-2003-127649, the cabin heater performs heat exchange between the combustion exhaust gas and the air in the cabin. The exhaust gas is configured to be exhausted outside the cabin.

  The combustion exhaust gas from the cabin heater has a high temperature of about 200 ° C. even after heat exchange with the air in the cabin. For this reason, if a person touches the combustion exhaust gas of the cabin heater or the exhaust pipe that guides the combustion exhaust gas, there is a risk of burns. Therefore, an exhaust cover is provided at the front end of the exhaust pipe of the combustion exhaust gas of the cabin heater so that it cannot be touched by a person. However, such an exhaust cover itself has a high temperature, and there is a possibility that a person who touches it may be burned, or radiant heat may adversely affect surrounding electronic devices.

JP 2003-127649 A

  In view of the above circumstances, an object of the present invention is to provide an exhaust device for a cabin heater that can reduce the temperature of combustion exhaust gas of the cabin heater.

  An exhaust device for a cabin heater according to the present invention, which has been made to solve the above-mentioned problems, is an exhaust device for a cabin heater that warms the air in the cabin of a construction machine by the combustion heat of fuel, and the exhaust gas from the cabin heater A chamber connected to an exhaust pipe for guiding the exhaust pipe, the exhaust pipe protrudes into the chamber, the chamber is formed on the downstream side of the exhaust pipe in the flow direction of the combustion exhaust gas, and an intake port for taking in outside air, It has an exhaust port which discharges the combustion exhaust gas introduced from the exhaust pipe and the outside air taken in from the intake port to the outside.

  The cabin heater exhaust system lowers the temperature by sucking outside air into the chamber from the intake port by the flow of combustion exhaust gas introduced from the exhaust pipe into the chamber, and mixing the outside air with the combustion exhaust gas. The discharged gas is discharged to the outside from the exhaust port. Thus, the cabin heater exhaust device dilutes with the outside air to lower the temperature of the combustion exhaust gas of the cabin heater, so that even if a person touches the exhaust gas discharged from the chamber to the outside, no burn will occur.

  In the cabin heater exhaust apparatus, the chamber may have an introduction wall to which the exhaust pipe is connected, and the intake port and the exhaust port may open in a plane substantially perpendicular to the introduction wall. According to this configuration, the exhaust device for the cabin heater bends the combustion exhaust gas in the chamber and releases it to the outside, so that the venturi effect can be promoted and the outside air can be efficiently sucked from the suction port. The outside air and the combustion exhaust gas can be mixed efficiently.

  In the cabin heater exhaust apparatus, the chamber further includes a flat collision wall disposed in front of the exhaust pipe and having a normal direction extending between the exhaust pipe and the exhaust port. Also good. According to this configuration, the combustion exhaust gas accompanied by the outside air collides with the collision wall, so that the outside air and the combustion exhaust gas can be mixed more reliably.

  The cabin heater exhaust device may include a partition wall disposed between the intake port and the exhaust port. According to this configuration, the mixed gas of the combustion exhaust gas exhausted from the exhaust port and the outside air can be prevented from interfering with the outside air sucked from the intake port, and sufficient outside air can be sucked in. The temperature of the exhaust gas can be lowered.

  In the cabin heater exhaust apparatus, a tip of the partition may be bent toward the introduction wall. According to this configuration, since the venturi effect can be promoted, the amount of outside air to be sucked can be increased and the temperature of the combustion exhaust gas can be further lowered.

  As described above, the exhaust device for a cabin heater according to the present invention can reduce the temperature of the combustion exhaust gas of the cabin heater.

It is a typical side view showing a construction machine provided with a heating system which has an exhaust device for cabin heaters of one embodiment of the present invention. It is a typical side view which shows the heating system of the construction machine of FIG. FIG. 3 is a schematic cross-sectional view of the cabin heater exhaust device of FIG. 2. It is a figure which shows the simulation result of the surface temperature of the exhaust apparatus which concerns on this invention. It is a figure which shows the simulation result of the gas temperature inside the exhaust apparatus which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[Construction machinery]
FIG. 1 shows a construction machine provided with an exhaust device for a cabin heater according to an embodiment of the present invention. More specifically, the construction machine in FIG. 1 is a crawler crane.

  The crawler crane in FIG. 1 includes a lower traveling body 1 capable of self-propelling and an upper revolving body 2 provided on the lower traveling body 1 so as to be able to pivot in the horizontal direction. The lower traveling body 1 has a pair of crawlers 3 as a traveling device. The upper swing body 2 has a cabin (cab) 4 on which a driver is boarded, and a crane attachment (work implement) 5 is provided in a tiltable manner at the front. The crawler crane includes a heating system 6 that warms the air in the cabin 4.

<Heating system>
As shown in FIG. 2, the heating system 6 is disposed in the cabin 4, and a cabin heater 7 that warms the air in the cabin 4 by the combustion heat of the fuel, and a combustion exhaust gas of the cabin heater 7 is exhausted while cooling. And an exhaust device 8 according to an embodiment of the present invention disposed outside the cabin 4 (under the floor).

  More specifically, the heating system 6 includes an intake pipe 9 for the cabin heater 7 to suck in combustion air, an exhaust pipe 10 for guiding the combustion exhaust gas from the cabin heater 7 and exhausting it outside the cabin 4, and a cabin heater. The intake filter 11 for taking in the air in the cabin 4, the warm air duct 12 for releasing the warmed air in the cabin heater 7 into the cabin 4, and fuel from the fuel pump (not shown) to the cabin heater 7 It has a fuel pipe 13 for supply, and an electrical cable 14 for supplying power to the cabin heater 7 and inputting / outputting control signals.

(Cabin heater)
The cabin heater 7 mixes the air flow path in the cabin 4 that is taken in from the intake filter 11 and discharged from the hot air duct 12, the combustion air sucked from the intake pipe 9 and the fuel supplied from the fuel pipe 13. The combustion exhaust gas flow path generated by burning is separated from the combustion exhaust gas, and heat exchange is performed between the air in the cabin 4 and the combustion exhaust gas.

  As such a cabin heater 7, for example, a combustion heater manufactured by Bevast can be used.

  The cabin heater 7 is preferably disposed in a dead space below the seat in the cabin 4 or behind the seat.

(Exhaust device)
As shown in FIG. 3, the exhaust device 8 includes a chamber 15 to which the exhaust pipe 10 is connected. The exhaust pipe 10 is connected so as to protrude into the chamber 15.

  The chamber 15 has an intake port 16 for taking in outside air and an exhaust port 17 for discharging combustion exhaust gas introduced from the exhaust pipe 10 and outside air taken in from the intake port 16 to the outside. The chamber 15 in the present embodiment is formed in a hood shape having an open bottom, and an intake port 16 and an exhaust port 17 are formed by dividing the bottom opening into two. In the chamber 15, the intake port 16 is disposed upstream of the exhaust port 17 in the exhaust pipe 10 in the flow direction of the combustion exhaust gas.

  More specifically, the chamber 15 is arranged vertically and has a square-shaped introduction wall 18 to which the exhaust pipe 10 is connected, and a square-shaped top wall 19 that extends substantially vertically from the upper edge of the introduction wall 18. A rectangular flat plate-like collision wall 20 extending downward from the top edge of the top wall 19 and inclined to the opposite side of the introduction wall 18; An end wall 21 extending to an equal height and a pair of pentagonal side walls 22 extending from both side edges of the introduction wall 18 and connected to the top wall 19, the collision wall 20 and the side edges of the end wall 21 are provided. . The chamber 15 further includes a partition wall 23 disposed between the pair of side walls 22 and dividing the intake port 16 and the exhaust port 17. A bracket 24 that holds the exhaust pipe 10 is provided on the top surface of the top wall 19 of the chamber 15.

  As a material of the chamber 15, for example, a plated steel plate, a stainless steel plate or the like can be used. In addition, the thickness of the material constituting the chamber 15 can be set to 1.2 mm or more and 2.0 mm or less, for example. Moreover, you may cover the outer side with the heat insulating material so that a person cannot touch the chamber 15 directly.

  The height of the introduction wall 18 can be, for example, 15 cm or more and 30 cm or less. The width of the introduction wall 18 can be, for example, 5 cm or more and 20 cm or less. The extension length of the top wall 19 can be, for example, 3 cm or more and 10 cm or less. As a space | interval of the introduction wall 18 and the end wall 21, it can be 15 cm or more and 30 cm or less, for example.

  In the exhaust device 8, the combustion exhaust gas blown from the exhaust pipe 10 sucks the upstream air by the venturi effect, so that the outside air is sucked into the chamber 15 from the intake port 16, and the outside air and the combustion exhaust gas are mixed. This lowers the exhaust temperature.

  The average diameter of the exhaust pipe 10 can be, for example, 15 mm or more and 30 mm or less. The distance from the introduction wall 18 to the tip of the exhaust pipe 10 is such that the combustion exhaust gas introduced from the exhaust pipe 10 is prevented from flowing to the intake port 16 side, so that the outside air is reliably sucked from the intake port 16. It is preferable that the distance is equal to or more than the distance from 18 to the upper end of the partition wall 23. Specifically, the amount of protrusion of the exhaust pipe 10 into the chamber 15 can be, for example, not less than 0.2 times and not more than 0.5 times the distance between the introduction wall 18 and the end wall 21. When the amount of protrusion of the exhaust pipe 10 into the chamber 15 is less than the above lower limit, there is a possibility that the outside air cannot be sucked by making the intake port 16 negative pressure. Conversely, when the amount of protrusion of the exhaust pipe 10 into the chamber 15 exceeds the upper limit, the flow of the combustion exhaust gas in the chamber 15 may be disturbed, and the intake of outside air from the intake port 16 may be insufficient.

  The exhaust pipe 10 passes through the upper part of the introduction wall 18 and is disposed so as to be inclined horizontally (perpendicular to the introduction wall 18) or slightly downward (exhaust port 17 side). The exhaust pipe 10 may be offset from the center in the horizontal direction of the introduction wall 18 in order to arrange the heating system 6 efficiently. Specifically, the center height of the portion of the exhaust pipe 10 that penetrates the introduction wall 18 can be, for example, 75% or more and 90% or less of the height of the introduction wall 18. Moreover, as an inclination angle with respect to the horizontal direction of the exhaust pipe 10, it can be set to 0 degree or more and 15 degrees or less, for example.

  Moreover, it is preferable that the exhaust pipe 10 is disposed so that the collision wall 20 is positioned in front of the exhaust pipe 10 (on the shaft on the downstream side in the flow direction of the combustion exhaust gas). Thereby, the combustion exhaust gas blown out from the exhaust pipe 10 into the chamber 15 collides with the collision wall 20 and the combustion exhaust gas is agitated, so that the combustion exhaust gas can be efficiently mixed with the outside air sucked from the intake port 16. it can.

  The inclination of the collision wall 20 is such that the normal direction is directed between the exhaust pipe 10 and the exhaust port 17. Thereby, the flow resistance of the combustion exhaust gas from the exhaust pipe 10 to the exhaust port 17 does not become too large, and the suction efficiency of the outside air due to the venturi effect can be increased while maintaining the flow rate of the combustion exhaust gas. A specific inclination angle of the collision wall with respect to the top wall 19 can be, for example, 30 ° or more and 60 ° or less, typically 45 °.

  The partition wall 23 divides the lower opening of the chamber 15 into two to define the intake port 16 and the exhaust port 17, and also divides the lower space in the chamber 15 into two to have the intake port 16 at the lower end. Then, an intake passage extending toward the exhaust pipe 10 and an exhaust passage having the exhaust port 17 at the lower end and the collision wall 20 at the upper end are defined. Since the exhaust port 17 passes through the combustion exhaust gas introduced from the exhaust pipe 10 and the outside air sucked from the intake port 16, it is desirable to make the opening area of the exhaust port 17 larger than the opening area of the intake port 16. The ratio of the opening area of the exhaust port 17 to the opening area of the intake port 16 can be, for example, 1.2 or more and 2.0 or less.

  The partition wall 23 may rise vertically from the lower end of the chamber 15, and the end portion (upper end portion) on the exhaust pipe 10 side is preferably bent toward the introduction wall 18. By bending the upper end portion of the partition wall to the introduction wall side, the downward expansion of the combustion exhaust gas immediately after being introduced from the exhaust pipe 10 is suppressed, and the combustion exhaust gas flows smoothly toward the exhaust port 17, The suction of outside air by the venturi effect can be promoted.

  The height of the vertical portion of the partition wall 23 is, for example, the height of the chamber 15 in order to smooth the flow of the outside air sucked from the intake port 16 and the flow of the mixed gas of the combustion exhaust gas discharged from the exhaust port 17 and the outside air. It can be 0.3 times or more and 0.6 times or less (the height of the introduction wall 18). When the height of the vertical portion of the partition wall 23 is less than the lower limit, the flow of the mixed gas of the combustion exhaust gas and the outside air may be disturbed and flow into the intake passage from the exhaust passage. Conversely, if the height of the vertical portion of the partition wall 23 exceeds the above upper limit, the negative pressure at the intake port 16 may be reduced.

  The vertical distance between the upper end of the partition wall 23 and the exhaust pipe 10 can be, for example, not less than 0.5 cm and not more than 3 cm. Further, the length of the inclined upper end portion of the partition wall 23 can be, for example, 0.1 to 0.3 times the height of the chamber 15. Further, the inclination angle of the upper end portion of the partition wall 23 can be, for example, 30 ° or more and 60 ° or less, and is preferably substantially parallel to the collision wall 20.

<Advantages>
The exhaust device 8 sucks outside air into the chamber 15 from the intake port 16 by the venturi effect generated by the flow of the combustion exhaust gas introduced from the exhaust pipe 10 into the chamber 15, and mixes the outside air with the combustion exhaust gas in the chamber 15. Then, the temperature is lowered and discharged from the exhaust port 17 to the outside. In this way, the exhaust device 8 is diluted with outside air to lower the temperature of the combustion exhaust gas of the cabin heater, so that even if a person touches the exhaust gas discharged from the chamber 15 to the outside, no burns are caused.

[Other Embodiments]
The said embodiment does not limit the structure of this invention. Therefore, in the above-described embodiment, the components of each part of the above-described embodiment can be omitted, replaced, or added based on the description and common general knowledge of the present specification, and they are all interpreted as belonging to the scope of the present invention. Should.

  In the exhaust device for the cabin heater, the exhaust pipe needs to protrude into the chamber, but the main body of the exhaust pipe does not need to extend into the chamber. And an exhaust pipe main body may be connected to the outer end of the pipe body. Further, the partition wall may be one whose end is not inclined.

  In the cabin heater exhaust apparatus, the intake port and the exhaust port may be disposed on different walls. For example, the intake port may be formed in the introduction wall, and the exhaust port may be formed in the end wall. In this case, the chamber may have a bottom wall that seals the bottom surface.

  In the cabin heater exhaust apparatus, the chamber may not have a collision wall. Moreover, you may have the wall curved instead of the collision wall so that a ceiling wall and an end wall may be connected.

  In the cabin heater exhaust device, the partition wall may be omitted depending on the arrangement of the intake port and the exhaust port. In addition, the partition wall in the cabin heater exhaust device is not limited to one that crosses between the pair of side walls, and may be, for example, a cylindrical body that extends from the inner periphery of the intake port into the chamber. Further, the partition wall in the cabin heater exhaust device may be any partition as long as it can partition at least a part of the space in the chamber, and may be a non-plate shape such as an aggregate of cylindrical bodies.

  In the description of the above embodiment, the description has been given using the vertical relationship in the embodiment, but the direction of the chamber in the cabin heater exhaust device is arbitrary, and the direction in the above embodiment is read and understood according to the direction. There must be.

  EXAMPLES Hereinafter, although this invention is explained in full detail based on an Example, this invention is not interpreted limitedly based on description of this Example.

  In order to confirm the effect of the present invention, an exhaust device for a cabin heater according to the present invention is modeled on a computer, and a simulation for introducing combustion exhaust gas from an exhaust pipe is performed to obtain an exhaust device for a cabin heater and an exhaust device for a cabin heater The temperature of the gas inside was confirmed.

  The model of the exhaust system for the cabin heater has a chamber introduction wall width of 110 mm, an introduction wall height of 180 mm, a ceiling wall extension length of 60 mm, a collision wall inclination angle of 45 °, an introduction wall and an end wall. The distance between the inlet wall and the partition wall at the intake port is 65 mm, the height of the vertical part of the partition wall is 100 mm, the length of the upper end part is 30 mm, the inclination angle of the upper end part is 45 °, the diameter of the exhaust pipe Is 28 mm, and the amount of protrusion of the exhaust pipe is 55 mm.

  Using this model, a simulation was performed in which combustion exhaust gas having a temperature of 200 ° C. was introduced from the exhaust pipe at a flow rate of 2.56 m / s. FIG. 4 shows the temperature distribution on the chamber surface, and FIG. 5 shows the temperature distribution of the gas in the chamber.

  As shown in the figure, it was confirmed that the exhaust gas temperature could be lowered to about 50 ° C. or higher and 100 ° C. or lower by using the cabin heater exhaust device according to the present invention. If it is this temperature, it is thought that the danger of causing a burn by exhaust gas is small enough.

  The exhaust device for a cabin heater according to the present invention can be particularly suitably used for reducing the exhaust temperature of a cabin heater for a vehicle such as a construction machine.

DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper turning body 3 Crawler 4 Cabin 5 Crane attachment 6 Heating system 7 Cabin heater 8 Exhaust device 9 Intake pipe 10 Exhaust pipe 11 Intake filter 12 Hot air duct 13 Fuel piping 14 Electrical cable 15 Chamber 16 Inlet 17 Exhaust Port 18 Introduction wall 19 Top wall 20 Collision wall 21 End wall 22 Side wall 23 Partition wall 24 Bracket

Claims (3)

An exhaust device for a cabin heater that heats the air in the cabin of a construction machine by combustion heat of fuel,
A chamber to which an exhaust pipe for guiding combustion exhaust gas of the cabin heater is connected;
The exhaust pipe projects into the chamber;
An intake port for taking in the outside air; and an exhaust port for discharging the combustion exhaust gas introduced from the exhaust pipe and the outside air taken in from the intake port to the outside. I have a,
The chamber has an introduction wall to which the exhaust pipe is connected, and a partition wall disposed between the intake port and the exhaust port;
The partition end of the exhaust pipe side cabin heater exhaust apparatus characterized that you have bent toward the introduction wall. Upper SL inlet and the exhaust port exhaust system cabin heater according to claim 1 which is open to the introduction wall substantially perpendicular plane. The chamber is disposed in front of the exhaust pipe, the normal direction according to claim 1 or claim 2 further comprising a plate-shaped collision wall is a direction between the exhaust pipe and the exhaust port Exhaust device for cabin heater.