JPH03294650A - Exhaust heat recovery device of underwater engine - Google Patents

Abstract

PURPOSE:To improve usage convenience of an equipment connected to an exhaust heat exchanger by directly connecting the exhaust heat exchanger to an exhaust port of an engine, and increasing a temperature-rise ratio of heat medium extracted at the time of starting. CONSTITUTION:A primary exhaust heat exchanger 5a is directly connected to an exhaust port 6 of an engine 2, while a secondary exhaust heat exchanger 5b is provided on the way of an exhaust passage 4. The primary exhaust heat exchange 5a is in contact to and is fixed to an upper surface of a cylinder of the engine 2, so that the exhaust heat of the engine 2 is effectively recovered through the primary exhaust heat exchanger 5a. Exhaust from an exhaust port 6 of the engine 2 is introduced into the exhaust heat exchanger 5a without being in contact to cooling water 3. The exhaust heat is thus prevented from being absorbed in the cooling water before it reaches the exhaust heat exchanger 5a from the engine 2. A temperature-rise ratio is remarkably increased in hot water which is supplied by the exhaust heat exchanger at the time of starting, and thereby the usage convenience of a terminal equipment is improved.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an exhaust heat recovery device for a submerged engine, and in particular, to an exhaust heat recovery device for a submerged engine that is connected to the exhaust heat recovery device by increasing the temperature rise gradient of the heat medium taken out at the time of startup. This invention relates to an exhaust heat recovery device for a submerged engine that is designed to improve the usability of terminal equipment.

<Conventional technology> Many of the various terminal devices currently used in society are powered by electricity, and from the perspective of protecting energy resources, energy conservation measures, including power generation systems, are being seriously considered. has been done.

A cogeneration system is a typical example of such energy-saving measures, in which an engine is operated using gas fuel, etc., and the engine drives a working machine such as a generator to effectively utilize the mechanical output of the engine for tasks such as power generation. This system recovers engine exhaust heat and uses it effectively for air conditioning, hot water supply, baths, etc.

In order to recover as much exhaust heat as possible from the engine, the exhaust heat recovery device in this cogeneration system is used, for example, by submerging the engine 2 in cooling water 3 in a water tank 1, as shown in FIG. An exhaust heat recovery device for a submerged engine is already known, which recovers the exhaust heat of the engine 2 by using the engine 2 as a heat medium.

In this conventional submerged engine exhaust heat recovery device, a large amount of cooling water 3 absorbs the exhaust heat of the engine 2, so the temperature rise gradient of the cooling water 3 at the time of startup is gentle, and the cooling water 3 is connected to the water tank 1 via the hot water outlet pipe 8. This is a considerable disadvantage in improving the usability of connected terminal equipment.

Therefore, in order to obtain a high-temperature heat medium at the time of startup and also take out a heat medium with a temperature different from that of the cooling water, an exhaust heat exchanger 5 is installed in the middle of the exhaust path 4 led out from the engine 2, for example, as shown in FIG. The present inventor first conceived of a submerged one-engine heat generation recovery device in which a guide beak 9 is provided at the outlet of a water pipe 7 that supplies water to a water tank 1 to direct the supplied water toward the exhaust heat exchanger 5.

In the heat recovery device for a submerged engine according to the present invention, since water is applied to the exhaust heat exchanger 5 whose temperature rises relatively rapidly at startup, the temperature rise gradient of the cooling water 3 in the water tank 1 becomes steep.

Furthermore, since the temperature rise gradient of the heat medium supplied to the exhaust heat exchanger 5 is much steeper than that of the cooling water 3 in the water tank 1,
By guiding the hot water from the exhaust heat exchanger 5 to the terminal equipment via the hot water outlet pipe 8b, the usability of the terminal equipment can be improved.

<Problems to be Solved by the Invention> However, in the submerged engine waste heat recovery device of the previous invention, the exhaust heat exchanger 5 is provided in the middle of the exhaust path 4 led out from the engine 2. During startup, the exhaust gas is cooled by the cooling water 3 while reaching the exhaust heat exchanger 5 from the engine 2, so the cold water guided by the guide beak 9 hits the exhaust heat exchanger 5 and cools the exhaust heat exchanger 5. As a result, the temperature rise of the heat medium recovered by the exhaust heat exchanger 5 is delayed, and this remains a major dissatisfaction in improving usability.

The present invention has been made in consideration of the above circumstances,
An object of the present invention is to provide a heat recovery device for a submerged engine, which increases the usability of equipment connected to the exhaust heat recovery device by steepening the temperature rise gradient of the heat medium taken out at the time of startup. It is something.

<Means for Solving the Problems> The present invention, as shown in FIGS. 1 and 2, for example, involves submerging an engine 2 in cooling water 3 in a water tank 1,
The above purpose is achieved in an exhaust heat recovery device for a submerged engine in which an exhaust heat exchanger 5a is interposed in the exhaust path 4 led out from the exhaust gas, and exhaust heat is absorbed and recovered by a heat medium supplied to the exhaust heat exchanger 5a. In order to achieve this, the exhaust heat exchanger 5a is directly connected to the exhaust port 6 of the engine 2.

Function> In the present invention, the exhaust gas discharged from the exhaust port 6 of the engine 2 does not come into contact with the cooling water 3, and the exhaust heat exchanger 5
It is possible to prevent the exhaust heat from being absorbed by the cooling water before reaching the exhaust heat exchanger 5a from the engine 2.

Embodiment Hereinafter, an embodiment of the present invention will be specifically described based on FIGS. 1 and 2.

FIG. 1 is a configuration diagram of an exhaust heat recovery device for a submerged engine according to an embodiment of the present invention, and FIG. 2 is a perspective view thereof.

This submerged engine exhaust heat recovery device includes a water tank 1 filled with cooling water 3, an engine 2 in the water tank 1, an exhaust path 4 led out from the engine 2, and an exhaust heat recovery device interposed in the exhaust path 4.
Both the secondary and secondary exhaust heat exchangers 5a and 5b are submerged in cooling water 3.

A water pipe 7 that supplies tap water from the outside is connected to the water tank 1 and both the primary and secondary exhaust heat exchangers 5a and 5b, while outlet pipes 8 and 8a take out the tap water supplied from each.
8b is derived.

A device that uses a large amount of hot water whose temperature is stable at a relatively low temperature, such as a bathtub, is connected to the tip of the hot water pipe 8 of the aquarium 1, and hot water is returned from the device to the aquarium 1 as needed. A return pipe is provided. Here, the hot water outlet pipe 8 may be configured to be directly connected to the bathtub, or a heat exchanger may be interposed in the middle so that the hot water supplied from the hot water outlet pipe 8 indirectly heats the bath water. may be configured.

In addition, the tips of both the primary and secondary exhaust heat exchangers 5a and 5b are
Table or outlet pipe 8, each requiring relatively high temperature hot water
This allows for hot water to be supplied to the area.

Of the primary and secondary exhaust heat exchangers 5a and 5b, the primary exhaust heat exchanger 5a is directly connected to the exhaust port 6 of the engine 2, and the secondary exhaust heat exchanger 5b is located in the middle of the exhaust path 4. It is an intervention.

The engine 2 is a horizontal engine in which the cylinder axis is horizontal and the exhaust port 6 opens on the top surface of the cylinder.
By fixing the primary exhaust heat exchanger 5a in contact with the upper surface of this cylinder, the exhaust heat of the engine 2 can be recovered more efficiently via the primary exhaust heat exchanger 5a.

In addition, the terminal of the water pipe 7 connected to the water tank 1 is opened into a guide beak 9 provided in the water tank 1 in order to steepen the temperature rise gradient of the cooling water 3 in the water tank 1 at the time of startup. Tap water spouted from the end of the pipe 7 is directed to the primary exhaust heat exchanger 5a by a guide beak 9.

Further, the muffler 11 of the engine 2 can be placed inside the water tank 1, but in this embodiment, it is placed outside the water tank 1 in order to facilitate maintenance work.

In this submerged engine exhaust heat recovery device, the exhaust gas discharged from the exhaust port 6 of the engine 2 directly flows into the primary exhaust heat exchanger 5a, so that the exhaust gas flows into the primary exhaust heat exchanger 5a. A large amount of heat is transferred to the primary exhaust heat exchanger 5 without being cooled by the cooling water 3 in the water tank 1.
It can be absorbed into the tap water supplied to a. Therefore, the rising temperature gradient of the hot water discharged from the primary exhaust heat exchanger 5a at the time of startup can be made sufficiently steep, and the primary exhaust heat exchanger 5a can be used as an instantaneous water heater. It is possible to improve the usability of terminal equipment.

In addition, the temperature rise gradient of the hot water supplied from the secondary exhaust heat exchanger 5b at the time of starting the cooling water Although it is much steeper than in case 3, since the exhaust heat is recovered in the primary exhaust heat exchanger 5a and the upstream part of the exhaust passage 4 before it flows into the secondary exhaust heat exchanger 5b, the primary exhaust heat The temperature rise gradient of the hot water supplied from the exchanger 5a at the time of startup is slower.

Furthermore, the temperature rise gradient of the cooling water in the water tank 1 at the time of startup is slowed down by exhaust heat recovery in the primary exhaust heat exchanger 5a and the secondary exhaust heat exchanger 5b;
Since the cooling water flowing in from the terminal hits the primary exhaust heat exchanger 5a and is rapidly heated, the temperature becomes steeper.

The temperature of the hot water supplied from each outlet pipe 8, 8a, 8b varies depending on the flow rate of each outlet pipe 8, 8a, 8b. Hot water of high temperature is obtained in the order of exchanger 5b and water tank 1.

Furthermore, in the present invention, fins can be added to the outer surface of the circumferential wall of the exhaust passage 4 in the water tank 1 in order to further steepen the temperature rise gradient of the cooling water 3 in the water tank 1 at the time of starting.

Furthermore, in the above embodiment, tap water is supplied to the water tank 1, but in the present invention, the heat medium filled in the water tank 1, the primary and secondary exhaust heat exchange Vessel 5a
・The heat medium supplied to 5b is not limited to tap water, and may be used instead of water, such as oil, unless the exhaust heat of the engine 1 is directly absorbed into the water used for hot water supply, bathing, etc. It is also possible to use various known heating media.

<Effects of the Invention> As explained above, the submerged engine exhaust heat recovery device according to the present invention directly connects the exhaust heat exchanger to the engine exhaust port, so that the exhaust heat discharged from the engine exhaust port is By introducing the exhaust heat into the exhaust heat exchanger without coming into contact with the cooling water, the exhaust heat can be prevented from being absorbed by the cooling water before reaching the exhaust heat exchanger from the engine, and the hot water supplied by the exhaust heat exchanger at the time of startup can be prevented. It is possible to significantly steepen the temperature rise gradient and improve the usability of the terminal equipment.

[Brief explanation of drawings]

FIG. 2 is a configuration diagram of an exhaust heat recovery device. 1... Water tank, 2... Engine, 3... Cooling water, 4
...Drainage path, 5a...Primary exhaust heat exchanger, 5b...
・Secondary exhaust heat exchanger, 6...exhaust port. Patent applicant Kubota Co., Ltd. 0D iY) C\

Claims (1)

[Claims] 1. The engine (2) is submerged in cooling water (3) in the water tank (1), and the exhaust path (4) is led out from the engine (2).
An exhaust heat exchanger (5a) is interposed in the exhaust heat exchanger (5a).
In a submerged engine exhaust heat recovery device that absorbs and recovers exhaust heat into a heating medium supplied to the submerged engine, the exhaust heat exchanger (5a) is directly connected to the exhaust port (6) of the engine (2). Features: Exhaust heat recovery device for submerged engines