JP2548667B2 - Heat exchange device between dirty hot waste water and fresh water - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanging device for hygienically and safely exchanging heat between high-temperature wastewater and low-temperature fresh water using the principle of a heat pipe. The present invention relates to a heat exchange device which is effective not only for heat exchange with fresh water, but also for exchanging heat between various types of dirty factory wastewater containing foreign matters and various types of dirty wastewater and fresh water.

[0002]

2. Description of the Related Art Hot wastewater containing various contaminants or various contaminants such as fibers is discharged from various buildings such as houses, hotels, restaurants, public baths, hot springs, laundry factories, paper and pulp factories, and various factories. Has been done. But so far,
It has been difficult to effectively recover heat from these very dirty hot effluents.

When a heat exchanger which has been generally used so far is used for recovering heat from dirty hot waste water, a drainage pipe or a drainage passage in the heat exchanger is clogged with impurities,
There are problems that scales adhere to the pipes and drainage passages to reduce efficiency, and hot wastewater leaks into fresh water. Therefore, the conventional heat exchanger cannot be used for exchanging heat between dirty hot waste water and fresh water.

However, using the heat pipe principle,
It is possible to make a heat exchange device that can effectively transfer heat from dirty warm waste water to fresh water, and that does not come into contact with the warm waste water and fresh water, which is safe for hygiene.

The heat pipe is a closed-system heat transfer in which heat is continuously transferred from the evaporation part of the working liquid releasing heat to the condensing part of the working liquid by the action of various working liquids having a low boiling point. System. The working fluid liquefied by transferring heat in the condensing part that absorbs heat, by gravity or capillary action,
Return to the evaporation section, which releases heat.

[0006] Swedish Patent Nos. 7613962-5 and 7910472-5 show heat exchange devices that use the principle of a heat pipe to recover heat from hot waste water. The heat exchangers of these inventions are provided with a hot drainage storage tank and a fresh water storage tank above the hot drainage storage tank, and a heat pipe is installed between the lower hot drainage storage tank and the upper fresh water storage tank. It is a heat exchange device between hot water and fresh water that transfers heat from the water to the fresh water.

[0007]

[Problems to be Solved by the Invention] Swedish Patent No. 7
The heat exchange device described in 910472-5 has been demonstrated to work effectively in single-family homes. But,
Toilet sewage cannot flow into this heat exchanger, so the toilet sewage pipe must be installed separately from other drainage pipes. Therefore, the equipment cost increases. In addition, since a storage tank for warm wastewater is installed, waste will accumulate in this tank,
Also, odor is generated. For this reason, this storage tank must be constantly cleaned.

The present invention is a heat exchange device that uses the principle of a heat pipe to transfer heat from dirty hot wastewater to fresh water, and the heat exchange can be performed efficiently and sanitarily and safely without providing a hot wastewater storage tank. The object is to provide a device that can.

[0009]

SUMMARY OF THE INVENTION In the present invention, a hot drainage storage tank is not provided, and the hot drainage pipe is directly used as an evaporation part of a working liquid of a heat pipe for releasing heat. (EN) A heat recovery device for hot waste water, which is highly effective with a simple device, using the fresh water pipe attached to the as a condensing part of the working liquid of the heat pipe that directly absorbs heat. Therefore, the present invention has various improvements as described below.

That is, first, a warm drainage pipe that can be used as a part of a drainage pipe such as being buried in the ground and a fresh water pipe attached above it are provided, and these pipes are used as a working fluid for a heat pipe. The outer cylinder containing the steam is hermetically sealed to eliminate the need for a hot drainage storage tank.

As a result of investigating a large number of drainage pipes used for a long period of time, it was found that the bottom of the pipe through which the drainage flows had almost no filth adhered or accumulated, and was kept relatively clean. In addition, the drainage usually flows to the bottom portion that is ⅓ or less of the diameter of the drainage pipe. Therefore, if the drainage pipe can be used as the evaporation part of the working fluid of the heat pipe that releases heat, especially if the lower part of the drainage pipe can be efficiently used as the evaporation part, the storage tank of the warm drainage becomes unnecessary. Therefore, it is possible to make a heat exchange device that is easy to maintain.

In the above, the heat exchange is carried out by a counterflow method in order to improve efficiency.

Second, the heat pipe works in a nearly constant temperature range. However, since the temperature of the hot waste water often changes in the range of about 15 to 50 ° C., in the heat exchange device of the present invention, the heat pipe must function in such a temperature range.

Therefore, the heat exchange apparatus of the present invention is constructed by connecting in series several heat pipe units (hereinafter referred to as units) of outer cylinders having different boiling points of the enclosed working fluid. Therefore, the heat exchange is divided into several temperature range portions for each unit.

Thirdly, the temperature of the hot waste water is not constant but usually changes. Therefore, in order to obtain high efficiency, the heat exchange device for hot waste water must be able to immediately respond to changes in the temperature of the waste water.

Therefore, in the heat exchange device of the present invention, the material of the hot drainage pipe is a thin metal pipe (usually stainless steel), and the hot drainage pipe is made of a thermally sprayed metal, particularly aluminum or By providing a porous wick made of copper, the amount of working fluid in the heat pipe is reduced, and it is possible to immediately respond to changes in the temperature of wastewater.

Fourth, the temperature of waste water may change suddenly. For example, in the case of a house, when warm wastewater is discharged from the bathroom, dishwasher, washing machine using warm water, etc., the warm wastewater flows through the heat exchange device, and the working fluid of the heat pipe around the warm drainage pipe is discharged. The heat is immediately transferred to the fresh water pipe by evaporating, moving to the fresh water pipe side, and condensing there.
In some cases, the cold waste water is discharged immediately after the warm waste water is discharged, and this may enter the heat exchange device.

In this way, when the temperature of the waste water suddenly changes, it is necessary to prevent the heat already transferred to the fresh water pipe side from being lost.

Incidentally, the heat pipe can transfer heat only in one direction. That is, in such a case, since the evaporated working fluid of the heat pipe does not exist around the fresh water pipe, heat loss from the fresh water pipe side is automatically prevented. Therefore, in the device of the present invention, even if the temperature of the waste water changes suddenly, the heat once transferred from the high temperature hot drain side to the low temperature fresh water side is not lost from the fresh water side thereafter.

Fifth, in small buildings and small factories, discharge of warm waste water and use of warm fresh water may not be performed at the same time. For this reason, a storage tank and a circulation pump are provided for each of several units connected in series so that warmed fresh water can be circulated.

Therefore, when the warmed fresh water is not used, the warmed fresh water circulates every several units, and when the temperature of the hot waste water is high, the warmed fresh water that is circulating is circulated. The temperature of can be raised further.

[0022]

According to the present invention, as described above, a porous wick made of thermally sprayed metal, particularly aluminum or copper, is provided on the outer circumference of the tube, and the porous wick is located on the lower side of the outer circumference of the tube. Then, install a hot drain pipe that is thicker than other parts and a fresh water pipe placed above it in the outer cylinder, connect multiple units sealed with the working fluid of the heat pipe in series, This is a heat exchange device for hot wastewater and fresh water, in which wastewater and fresh water flow in opposite flows, and heat transfer from the warm wastewater to the fresh water is a heat exchange device using the principle of a heat pipe by evaporation and condensation of the working fluid.

The apparatus of the present invention does not have a hot drainage storage tank. Therefore, maintenance such as generation of odor or frequent cleaning of the tank is unnecessary, and it is very clean in terms of hygiene.

Next, since the hot drainage pipe and the fresh water pipe are separated from each other and heat is transferred by using the working liquid of the heat pipe as a medium, there is no possibility that dirty hot wastewater is mixed into the fresh water.
Therefore, it is possible to safely recover heat from a warm waste water containing pathogenic bacteria, for example, hot waste water discharged from a hospital or the like.

As mentioned above, the bottom of the pipe through which the drainage flows is kept relatively clean. Then, the drainage usually flows at a bottom portion of 1/3 or less of the diameter of the drainage pipe, and this is about 12 lower surfaces of the drainage pipe as shown in FIG.
It corresponds to the 0 ° portion.

Therefore, in the heat exchange apparatus of the present invention, a porous wick made of a thermally sprayed metal, particularly aluminum or copper, which permeates the working fluid of the heat pipe is provided on the outer periphery of the hot drainage pipe. However, the thickness of this porous wick is about 1 lower surface of the outer periphery of the hot drain pipe.
It is possible to efficiently transfer heat from the warm drain pipe to the fresh water pipe by configuring the thickness of the wick provided in the portion in the range of 20 ° to be larger than the thickness of the wick provided in the other portions.

If the porous wick provided on the lower surface of the outer periphery of the warm drainage pipe corresponding to the portion where the normal warm drainage flows in the warm drainage pipe is in the range of about 120 °, if it is relatively thick, it enters the wick. This is because the amount of the working fluid contained in the heat pipe is also relatively large, and the operation of removing the heat of the warm drainage and evaporating the working fluid through the warm drainage pipe is performed more efficiently.

The lower surface of the outer periphery of the hot drainage pipe is about 120.
It is preferable that the thickness of the porous wick provided in the portion within the range of 1 ° is in the range of approximately 1 to 2 mm. According to many experiments by the inventor, heat transfer from the hot drain pipe to the fresh water pipe was most effectively performed when the thickness of the wick provided in this portion was in the range of about 1 to 2 mm.
If the wick is thinner than this, the efficiency of heat transfer is reduced.
On the contrary, if the thickness is too thicker than this, the evaporation of the working fluid existing near the outer periphery of the hot drainage pipe inside the wick is hindered by the presence of the working fluid near the outer side of the wick, rather reducing the efficiency of heat transfer. did. Therefore, from the viewpoint of manufacturing cost and the efficiency of the apparatus, it is preferable that the upper limit of the thickness of the wick provided on the lower surface of the outer periphery of the hot drainage pipe in the range of about 120 ° is approximately 2 mm.

Since hot drainage does not normally flow in a portion of the outer periphery of the hot drainage pipe other than the range of the lower surface 120 °, it is not necessary to provide a thick wick in this portion. Therefore, a thin porous wick having a thickness of approximately 0.1 to 0.5 mm is provided in a portion other than the above range.

Due to the presence of the relatively thin porous wick, the working fluid falling from the fresh water pipe is prevented from hitting the hot drainage pipe and scattered, and the working fluid falling into the warm drainage pipe is protected by the thin wick. It is possible to flow downward along the outer peripheral surface of the hot drainage pipe and enter the relatively thick wick on the lower surface of the outer periphery of the hot drainage pipe.

Drains usually have to be slightly inclined in order to allow the drainage to flow through. Therefore, the working fluid of the heat pipe in the outer cylinder is not always in contact with the lower part of the hot drain pipe.

Therefore, a vertical protrusion having a porous wick is provided at the lower end of the outer periphery of the hot drainage pipe, and the working liquid in the lower portion of the outer cylinder is capillarized by the wick of the protrusion to cause a capillary phenomenon on the lower surface of the outer periphery of the hot drainage pipe. I try to rise to the wick.

Since the hot drainage pipe transfers heat quickly, it is better to use metal that is as thin as possible. However, when high-temperature drainage flows in the warm drain pipe, a large amount of the working liquid in the heat pipe evaporates suddenly and the pressure in the outer cylinder rises. For this reason, a reinforcing ring 6 is provided in order to protect the hot drain pipe from this pressure.

[0034]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, one unit of the present heat exchange device comprises an outer cylinder 1, a boundary plate 2, a hot drainage pipe 3, and a fresh water pipe 4. The hot drainage pipe 3 is usually composed of a thin stainless steel pipe.

A vertical projection 5 having a wick is attached to the hot drainage pipe 3, and a reinforcing ring 6 is attached so as to withstand the pressure in the outer cylinder 1.

The outer surface of the hot drainage pipe 3 has a thickness of approximately 1 ° at which the working fluid of the heat pipe penetrates into the lower surface at about 120 °.
A porous wick 7 of ~ 2 mm is provided. The thickness of the other parts outside the hot drainage pipe 3 is about 0.1.
A thin porous wick 26 of ~ 0.5 mm is provided.

The wick 7 may be composed of a thermally sprayed metal, in particular a thermally sprayed aluminum or copper.

The fresh water pipe 4 is usually made of a stainless steel pipe, and in order to improve heat transfer,
Fins or other similar to increase the heat transfer area can be attached.

The present heat exchange device is made of metal, and each part is airtightly joined.

A safety valve or a fusible plug 9 is attached to the outer cylinder 1 in case the temperature in the heat exchanger becomes excessively high and the pressure in the outer cylinder rises.

The working fluid 10 for the heat pipe is enclosed in the outer cylinder 1.

In this embodiment, the heat exchanging device is composed of one hot drain pipe 3 and two fresh water pipes 4, but the number of hot drain pipes and fresh water pipes is not limited to these. , Any number of combinations is possible.

Next, the operation of the heat exchange device will be described.

The warm drainage flows through the warm drainage pipe 3. The warm drainage pipe is rarely filled with drainage, and warm drainage water usually flows through the bottom of the warm drainage pipe 3.

The cold fresh water flows through the fresh water pipe 4 in the direction opposite to the warm waste water as shown by the arrow in FIG.

The heat of the warm drainage water 11 in the warm drainage pipe 3 is transmitted to the porous wick 7 through the wall of the warm drainage pipe 3. As a result, the hydraulic fluid 10 that has penetrated into the wick 7 deprives the heat of the warm waste water 11 and evaporates.

The vapor of the hydraulic fluid 10 moves to the fresh water pipe 4 above the hot drainage pipe 3, where it condenses into a liquid, and the latent heat obtained at the time of evaporation is supplied to the fresh water pipe 4. Warm fresh water.

The condensed and liquefied working liquid 10 flows down to the thin porous wick 26 on the upper part of the hot drain pipe 3 and the lower part of the outer cylinder 1, and permeates into the porous wick 7 again.

The evaporation of the working fluid 10, that is, the release of heat from the warm waste water and the condensation, that is, the absorption of heat by the fresh water, are continuously performed as long as the temperature of the warm waste water is higher than that of the fresh water.

On the other hand, immediately after the hot drainage passes through the drainage pipe 3, when the cold drainage passes through the drainage pipe 3 and the temperature of the drainage changes abruptly, the fresh water heated by the heat of the warm drainage that passed first. Since the evaporated working fluid of the heat pipe does not exist around the pipe 4, heat loss from the fresh water pipe 4 does not occur.

When the liquid surface level is low, the hydraulic fluid 10 at the bottom of the hot drainage pipe 3 penetrates into the wick 7 on the lower surface of the outer periphery of the hot drainage pipe 3 due to the capillary phenomenon caused by the wick of the protrusions 5.

FIG. 3 shows a connecting portion of two units of the heat exchange device.

The warm drainage pipe 3 is connected by the sleeve 12, and the fresh water pipe 4 is connected by attaching the connecting pipe 13 to the connecting portion 8 of the fresh water pipe 4.

In order to prevent the connection pipe 13 from being pushed away from the heat exchange device by the water pressure in the fresh water pipe, the connection pipe 13 is locked to the heat exchange device by the lock plate 14.

The heat exchanging device is kept warm by the heat insulating material 15.

FIG. 4 shows an outline of the entire heat exchange apparatus.

Each unit 16 of the heat exchange device of the present invention,
16a, 16b, 16c are connected in series, and the hot drainage pipes 17a, 17b passing through each unit can be used as a part of drainage pipes for drainage of the building or factory.

Fresh water is supplied to the fresh water pipe from the inflow port 18,
It is heated in each unit of the heat exchange device and taken out from the outflow port 19.

Here, if the working liquid 10 of the heat pipe sealed in each unit is made to have a different boiling point, even if the temperature of the hot waste water passing therethrough is different, one of them will be changed depending on each temperature. The heat exchange is efficiently performed in the unit, and the heat exchange apparatus as a whole can function even in different temperature ranges of hot waste water.

FIG. 5 shows the present heat exchange device in which a fresh water pipe is provided with a circulation device.

In a small building or small factory,
The discharge of warm wastewater and the use of warm fresh water may not occur simultaneously. Therefore, in such a case, this problem can be solved by circulating fresh water.

It is desirable to circulate fresh water for each of the heat exchange devices of several units.

In the embodiment of FIG. 5, wastewater flows from 17a through units 23a, 23b, 23c of the present heat exchanger and then through units 24a, 24b, 24c.

On the other hand, fresh water flows into the units 24c, 24b, 24a of the present heat exchange apparatus as indicated by the arrow 22,
Next, as shown by the arrow 25, the units 23c, 23b, 23
It enters into a, flows, and is taken out as shown by an arrow 26.

The units 24a, 24b of the present heat exchange device,
The fresh water heated in the group of 24c is returned to the unit 24c of the heat exchange device through the storage tank 20a by the circulation pump 21a.

Further, the units 23a, 23 of the heat exchange device
The fresh water heated in the groups b and 23c is returned to the unit 23c of the heat exchange device through the storage tank 20b by the circulation pump 21b.

In this way, the warmed fresh water can be circulated and stored in the heat exchange apparatus, and when the temperature of the hot waste water is high, the warmed fresh water can be further heated. it can.

[0069]

According to the present invention, a hot drainage storage tank is not provided,
Use the hot drainage pipe itself as the evaporation part of the working fluid of the heat pipe that releases heat, and use the fresh water pipe itself installed above the hot drainage pipe as the condensation part of the working fluid of the heat pipe that absorbs heat. By configuring
With a simple device, heat can be transferred from the hot drainage to the fresh water efficiently and hygienically.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view in which a part of one unit of a heat exchange device of the present invention is omitted.

FIG. 2 is a transverse sectional view of the same.

FIG. 3 is a vertical cross-sectional view of a connection portion of each unit of the heat exchange device.

FIG. 4 is a plan view showing a connection state of a plurality of units of the heat exchange device.

FIG. 5 is a plan view showing a connection state of a plurality of units similarly equipped with a circulation device.

[Explanation of symbols]

1 Outer Cylinder 2 Boundary Plate 3 Hot Drain Pipe 4 Fresh Water Pipe 5 Protrusion 6 Reinforcement Ring 7 Wick 9 Soluble Plug 10 Heat Pipe Working Liquid 11 Warm Drainage 12 Sleeve 13 Connection Pipe 15 Heat Insulation Material 16, 16a, 16b, 16c Heat Exchanger unit 17a, 17b Warm drainage pipe 18 Fresh water inlet 19 Fresh water outlet 20a, 20b Storage tank 21a, 21b Circulation pump 23a, 23b, 23c, 24a, 24b, 24c Heat exchanger unit 26 Thin wick

Claims (4)

(57) [Claims] 1. A heat absorbing side is composed of one or a plurality of substantially horizontally mounted fresh water pipes (4), and a heat releasing side is mounted substantially parallel to said fresh water pipes (4). And one or more hot drainage pipes (3), and a porous wick that allows the working fluid of the heat pipe to permeate is provided at the lower end of the outer periphery of the heat drainage pipe (3) that emits heat. A vertical projection is provided, and a fresh water pipe on the heat absorbing side and a hot drain pipe on the heat releasing side are enclosed in an airtight outer cylinder (1) containing the working fluid and vapor of the working fluid. And, a plurality of the outer cylinders are connected in series, dirty warm wastewater containing contaminants and fresh water are allowed to flow in a counter flow, and the counter flow type heat transfer from the warm drain pipe to the fresh water pipe is heat. Dissipates heat in the heat exchange device between hot wastewater and fresh water, which is performed using the principle of pipes A heat-sprayed metal that permeates the working fluid of the heat pipe, in particular, a porous wick made of aluminum or copper is provided on the outer periphery of the hot drainage pipe on the side, and the porous wick is on the side that releases the heat. A heat exchange device for polluted warm waste water containing contaminants and fresh water, characterized in that the lower surface side of the outer periphery of the warm waste water pipe is provided thicker than the porous wick in other portions. 2. The thickness of the porous wick is generally 1 to 2 mm at a portion of the lower surface of the outer periphery of the hot drainage pipe on the heat releasing side of about 120 °, and is generally 0.
The heat exchange device for polluted warm waste water containing contaminants and fresh water according to claim 1, wherein the heat exchange device has a diameter of 1 to 0.5 mm. 3. Both ends (8) of a fresh water pipe (4) for absorbing heat
Reinforcement (14) is provided in the said.
The heat exchange device between the dirty hot waste water containing contaminants and the fresh water described in. 4. The contaminants according to claim 1, wherein a circulation pump and a storage tank are provided for each of a plurality of outer cylinders of the heat exchange device connected in series to circulate fresh water. Heat exchange device between dirty hot water containing substances and fresh water.