GB2081854A

GB2081854A - Water heater

Info

Publication number: GB2081854A
Application number: GB8024770A
Authority: GB
Original assignee: LAY DENNIS
Current assignee: LAY DENNIS
Priority date: 1980-07-29
Filing date: 1980-07-29
Publication date: 1982-02-24
Also published as: GB2081854B

Abstract

A water heater for use in vehicles, in which water is heated by exhaust gases of an internal combustion engine by means of a water tube (4) disposed within the exhaust pipe (1) of the engine. The tube is adapted to be connected to a hot water utilization system including a hot water storage tank (8) and flow and return pipes (7, 9) through which water may be pumped or circulated by thermo-syphon. <IMAGE>

Description

SPECIFICATION Water heater This invention relates to a water heater to be heated by exhaust gases from an internal combustion engine and especially, though not exclusively suitabie for vehicles and boats powered by internal combustion engines.

It is known to make use of the water heated in the cooling system of vehicle water-cooled engines to heat the body of a vehicle. it is also known to use waste heat from an engine exhaust system to heat air or water for space heating or other purposes.

Prior proposals of this nature have tended to be elaborate and costly and it is an object of the present invention to provide a particularly simple and inexpensive water heater using heat from the exhaust system of an internal combustion engine.

The present invention consists in a water heater to be heated by exhaust gases from an internal combustion engine wherein the water heater comprises a length of watertube within the bore of a longitudinal extent of an exhaust pipe of the engine, the ends of the tube having extensions through the walls of the pipe adapted to be connected to a hot water utilizing system.

The term internal combustion engines is intended to include compression ignition engines.

The water tube may be plain copper tube and the extensions integral portions of the ends of the tube which project through holes in the walls of the exhaust pipe to provide external water connections.

The tube may be supported by welding or brazing the tube into the holes in the pipe. Instead of being plain the water tube may be finned or have some other form of extended surface to increase heat exchange.

The extent of the exhaust pipe in which the water tube is fitted is preferably close to the engine where the exhaust gases are hottest. This may, for example, be a section of exhaust pipe extending from an exhaust manifold to the next component in the exhaust system which may be a silencer or another length of pipe. In such a section of the exhaust pipe the water tube, being within the bore of the pipe, is in the flame path of the exhaust gases. As a result the temperature gradient across the wall of the water tube is steep and the rate of heat transfer high. It has been found that a length of plain copper tube of nominal 13 millimetre diameter inserted in the usual exhaust pipe in this section is capable of producing copious supplies of hot water without apparently adversely affecting the performance of the engine.A water heater can thus be made available for installation by providing, as a replacement of the original section of the pipe, a section of exhaust pipe already fitted with the water pipe. Installation is thus simple and inexpensive.

In most vehicles the exhaust pipe extends downwards from the manifold to pass under the floor of the vehicle body. Advantage can be taken of this difference in level by arranging that the ends of the water pipe are at different levels inducing thermosyphon circulation between the water heater tube and the hot water utilizing system.

The utilizing system may take any of a variety of forms and make use of hot water for space heating or for washing purposes, for example in a motor vehicle itself or, through suitable releasable connections in a trailer towed by the vehicle. A water utilization system supplied by a water heater according to the invention can be useful in private cars, motorized and trailer caravans, passenger coaches and commercial vehicles and in boats with inboard or outboard engines and in other situations in which internal combustion engines are used. The utilization system may include a hot water storage tank to which the water heater is connected by flow and return pipes through which water is circulated by a pump or naturally by thermo-syphon. With such a system hot water produced during a journey or voyage can be stored for use when the engine is not running.

One form of the invention is illustrated in the accompanying drawing which is a schematic view of a water heater according to the invention connected to a utilizing system.

A first section of exhaust pipe 1 has a flange 2 for connection to an exhaust manifold of an engine and, in the position of use, for example in a vehicle, extends downwards and rearwards to a portion 3 for connection to the remainder of the exhaust system.

Within the bore of this first section of exhaust pipe, and spaced from its walls, is inserted a length of plain copper tube forming a water tube 4 whose ends form an upper extension 5 and lower extension 6 passing out of the exhaust pipe through holes in the walls thereof. The extensions 5 and 6 are sealed in the holes by welding or brazing. The upper extension 5 is connected by a flow pipe 7 to the top of a hot water storage tank 8. The bottom of the tank 8 is connected by a return pipe 9 to the lower extension 6. The flow pipe 7 may be fitted with a tap 10 to enable hot water to be taken off and further hot water take off points, such as a tap 11 and connections 12, may be provided on the storage tank 8.

CLAIMS (Filed 28 July 1981) 1. A water heater to be heated by exhaust gases from an internal combustion engine wherein the water heater comprises a length of water tube within the bore of a longitudinal extent of an exhaust pipe of the engine, the ends of the tube having extensions through the walls of the pipe adapted to be connected to a hot water utilizing system.

2. A water heater according to Claim 1 wherein the extensions comprise integral portions of the ends of the tube.

3. A water heater according to Claim 1 or Claim 2 wherein the tube is plain.

4. A water heater according to Claim 1 or Claim 2 wherein the tube is finned.

5. A water heater according to any preceding claim wherein the extent of the exhaust pipe in which the tube is fitted is a section of the exhaust pipe extending from an exhaust manifold to the next component in the exhaust system 6. A water heater according to any preceding

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Water heater This invention relates to a water heater to be heated by exhaust gases from an internal combustion engine and especially, though not exclusively suitabie for vehicles and boats powered by internal combustion engines. It is known to make use of the water heated in the cooling system of vehicle water-cooled engines to heat the body of a vehicle. it is also known to use waste heat from an engine exhaust system to heat air or water for space heating or other purposes. Prior proposals of this nature have tended to be elaborate and costly and it is an object of the present invention to provide a particularly simple and inexpensive water heater using heat from the exhaust system of an internal combustion engine. The present invention consists in a water heater to be heated by exhaust gases from an internal combustion engine wherein the water heater comprises a length of watertube within the bore of a longitudinal extent of an exhaust pipe of the engine, the ends of the tube having extensions through the walls of the pipe adapted to be connected to a hot water utilizing system. The term internal combustion engines is intended to include compression ignition engines. The water tube may be plain copper tube and the extensions integral portions of the ends of the tube which project through holes in the walls of the exhaust pipe to provide external water connections. The tube may be supported by welding or brazing the tube into the holes in the pipe. Instead of being plain the water tube may be finned or have some other form of extended surface to increase heat exchange. The extent of the exhaust pipe in which the water tube is fitted is preferably close to the engine where the exhaust gases are hottest. This may, for example, be a section of exhaust pipe extending from an exhaust manifold to the next component in the exhaust system which may be a silencer or another length of pipe. In such a section of the exhaust pipe the water tube, being within the bore of the pipe, is in the flame path of the exhaust gases. As a result the temperature gradient across the wall of the water tube is steep and the rate of heat transfer high. It has been found that a length of plain copper tube of nominal 13 millimetre diameter inserted in the usual exhaust pipe in this section is capable of producing copious supplies of hot water without apparently adversely affecting the performance of the engine.A water heater can thus be made available for installation by providing, as a replacement of the original section of the pipe, a section of exhaust pipe already fitted with the water pipe. Installation is thus simple and inexpensive. In most vehicles the exhaust pipe extends downwards from the manifold to pass under the floor of the vehicle body. Advantage can be taken of this difference in level by arranging that the ends of the water pipe are at different levels inducing thermosyphon circulation between the water heater tube and the hot water utilizing system. The utilizing system may take any of a variety of forms and make use of hot water for space heating or for washing purposes, for example in a motor vehicle itself or, through suitable releasable connections in a trailer towed by the vehicle. A water utilization system supplied by a water heater according to the invention can be useful in private cars, motorized and trailer caravans, passenger coaches and commercial vehicles and in boats with inboard or outboard engines and in other situations in which internal combustion engines are used. The utilization system may include a hot water storage tank to which the water heater is connected by flow and return pipes through which water is circulated by a pump or naturally by thermo-syphon. With such a system hot water produced during a journey or voyage can be stored for use when the engine is not running. One form of the invention is illustrated in the accompanying drawing which is a schematic view of a water heater according to the invention connected to a utilizing system. A first section of exhaust pipe 1 has a flange 2 for connection to an exhaust manifold of an engine and, in the position of use, for example in a vehicle, extends downwards and rearwards to a portion 3 for connection to the remainder of the exhaust system. Within the bore of this first section of exhaust pipe, and spaced from its walls, is inserted a length of plain copper tube forming a water tube 4 whose ends form an upper extension 5 and lower extension 6 passing out of the exhaust pipe through holes in the walls thereof. The extensions 5 and 6 are sealed in the holes by welding or brazing. The upper extension 5 is connected by a flow pipe 7 to the top of a hot water storage tank 8. The bottom of the tank 8 is connected by a return pipe 9 to the lower extension 6. The flow pipe 7 may be fitted with a tap 10 to enable hot water to be taken off and further hot water take off points, such as a tap 11 and connections 12, may be provided on the storage tank 8. CLAIMS (Filed 28 July 1981)

1. A water heater to be heated by exhaust gases from an internal combustion engine wherein the water heater comprises a length of water tube within the bore of a longitudinal extent of an exhaust pipe of the engine, the ends of the tube having extensions through the walls of the pipe adapted to be connected to a hot water utilizing system.

3. A water heater according to Claim 1 or Claim 2 wherein the tube is plain.

4. A water heater according to Claim 1 or Claim 2 wherein the tube is finned.

5. A water heater according to any preceding claim wherein the extent of the exhaust pipe in which the tube is fitted is a section of the exhaust pipe extending from an exhaust manifold to the next component in the exhaust system

6. A water heater according to any preceding claim wherein the ends of the water tube are disposed at different levels.

7. A water heater according to any preceding claim wherein the tube is of nominal 13 mm diameter.

8. A water heater according to any preceding claim wherein the tube is made of copper.

9. A hot water system supplied by a water heater according to any preceding claim wherein a hot water storage tank is connected to the water heater by flow and return pipes through which water is circulated by a pump or by thermo-syphon.

10. A water heater substantially as described with reference to the accompanying drawings.