JP2001227880A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat exchanger having an enhanced heat recovery rate in which noncondensed gas stored during heat exchange can also be discharged to the outside. SOLUTION: A drain recovery unit 5 is coupled with the bottom section of a heat exchanging vessel 1 and an ejector 22 is coupled with the top section of the heat exchanging vessel 1. The ejector 22 is coupled, on the inlet side thereof, with a cooling fluid supply pipe 4 and, on the outlet side thereof, with a coiled cooling fluid supply pipe 11 along with the drain return opening 30 side of the drain recovery unit 5. Drain pressure fed from the drain recovery unit 5 is mixed with cooling fluid fed from the ejector 22 before being fed to the coiled cooling fluid supply pipe 11 for further heat exchange. Noncondensed gas stored in the heat exchanging vessel 1 during heat exchange is sucked by the ejector 22 and discharged to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of condensing steam remaining in a steam-using device or reevaporated steam generated from a high-temperature drain by exchanging heat with a cooling fluid such as water. The present invention relates to a device that eliminates steam that can accumulate with a moyamoya gas or uses hot water whose temperature has been increased by exchanging heat with a cooling fluid to separately use the retained heat of the steam.

[0002]

2. Description of the Related Art A conventional heat exchanger of this type is disclosed, for example, in Japanese Patent Application Laid-Open No. 60-120186. This is achieved by installing a cooling pipe inside a heat recovery chamber having a steam supply port, connecting the air release section to this heat recovery chamber, and storing condensate in the air release section and the lower part of the heat recovery chamber.
It is possible to prevent non-condensable gas, for example, air, from flowing into the heat recovery chamber and efficiently exchange heat.

[0003]

In the above-mentioned conventional heat exchanger, the cooling fluid that has exchanged heat with the steam through the cooling pipe and the drain in which the steam has condensed are separately collected. There was a problem that the rate was kept at a relatively low value of about 90%. This is because both the cooling fluid and the drain that have undergone heat exchange have a low temperature of about 50 ° C. to 60 ° C., and if they are collected separately, heat loss is large and the heat recovery efficiency is not improved.

In the above-mentioned conventional heat exchanger, it is possible to prevent the inflow of non-condensable gas such as air from the outside of the heat recovery chamber. , There is a problem that the non-condensable gas cannot be discharged to the outside.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the heat exchange rate by improving the heat recovery rate by increasing the temperature of the low-temperature recovered fluid as much as possible while allowing the non-condensable gas staying during the heat exchange to be discharged to the outside. Is to get a bowl.

[0006]

Means taken to solve the above problem is to supply steam and a cooling fluid to a heat exchange container, and to condense the steam by exchanging heat with the cooling fluid. A drain recovery device for recovering the drain by pumping the drain to the bottom of the heat exchange container is connected, and the drain reduction port of the drain recovery device is connected to the heat exchange container, and the inside of the heat exchange container and the suction chamber of the ejector are connected. In communication, the inlet side of the ejector is connected to a cooling fluid supply source, and the outlet side of the ejector is connected to the heat exchange container.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS By connecting a drain recovery device to the bottom of a heat exchange container and connecting a drain reduction port to the heat exchange container, drain condensed in the heat exchange container flows down to the drain recovery device. From the reducing port to the heat exchange container again. On the other hand, by connecting the ejector connected to the cooling fluid supply source to the inside of the heat exchange container and connecting the outlet side of the ejector to the heat exchange container, air and some steam as non-condensable gas in the heat exchange container Is sucked by the ejector, mixed with the cooling fluid, and supplied again from the outlet side into the heat exchange container. As described above, the mixed fluid of the cooling fluid and the drain supplied to the heat exchange container exchanges heat with the steam in the heat exchange container to form the steam into the drain, and at the same time, the temperature rises, and is recovered to a predetermined recovery location.

[0008] Rather than separately recovering the condensed drain and the cooling fluid that has undergone heat exchange, it exchanges heat with steam in a heat exchange vessel as a mixed fluid, thereby raising the temperature of the recovered fluid and increasing the heat recovery rate. Can be improved.

[0009] By sucking air as non-condensable gas in the heat exchange container by the ejector, the non-condensable gas accumulated in the container during heat exchange can be discharged to the outside of the heat exchange container by the ejector.

[0010]

In FIG. 1, a heat exchange vessel 1, a steam supply pipe 2 for supplying steam to be condensed, a drain discharge pipe 3 for discharging a drain condensed with steam, and a drain recovery connected to the drain discharge pipe 3 A heat exchanger is constituted by the device 5, the ejector 22 communicating with the top of the heat exchange vessel 1, and the cooling fluid supply pipe 4 connected to a cooling fluid supply source (not shown).

The heat exchange vessel 1 is a closed tank. The cooling fluid supply pipe 4 communicates with the coil 11 downward through a valve 6 via a valve 6, and is connected to a hot water recovery pipe 8 via a valve 7 from above. The steam supply pipe 2 is connected to the upper side of the heat exchange vessel 1 via a valve 21. By the steam supplied from the steam supply pipe 2, the cooling fluid in the coiled cooling fluid supply pipe 11 is heated and the temperature rises, and the steam deprived of heat is condensed to drain and flow down to the lower part of the tank 1. Is what you do.

A check valve 29 is connected between the bottom of the heat exchange vessel 1 and the drain inlet 28 of the drain recovery device 5 by the drain discharge pipe 3.
Connect through. The check valve 29 permits the passage of fluid only from the heat exchange container 1 to the drain recovery device 5,
The passage of fluid in the opposite direction is not allowed. The drain recovery port 30 of the drain recovery device 5 also communicates with the heat exchange container 1 via the check valve 31 and the conduit 16. This check valve 31
Is for allowing the fluid to pass only from the drain recovery device 5 to the heat exchange container 1 side.

In the upper part of the drain recovery unit 5, an inlet 32 and a pressure equalizing port 33 for the high-pressure operating fluid are provided. The high pressure working fluid inlet 32 is connected to the high pressure steam pipe 35 and also to the steam supply pipe 2 via the valve 36. On the other hand, the pressure equalizing port 33 is connected to the inside of the heat exchange container 1 via the pipe 34.

When the float (not shown) disposed inside is located at the lower part, the drain recovery device 5 closes the inlet 32 for the high-pressure operating fluid, opens the equalizing port 33, and opens the drain discharge pipe. 3 and check valve 29 and drain inlet 28
The drain in the heat exchange vessel 1 flows down into the recovery device 5 through the passage. When the drain is collected in the recovery device 5 and a float (not shown) is located at a predetermined upper portion, the pressure equalizing port 33 is closed, while the high-pressure operating fluid inlet 32 is opened, and the high-pressure steam pipe 35 is used as the high-pressure operating fluid. High-pressure steam flows into the recovery device 5, sends the internal drain through the reduction port 30, the check valve 31, and the pipe 16 into the heat exchange vessel 1, and furthermore, the coil-shaped cooling fluid supply pipe 11 and hot water It is collected from the collection pipe 8.

When the drain is collected and the water level in the collecting device 5 drops, the high-pressure operating fluid inlet 32 is closed again and the pressure equalizing port 33 is opened, so that the drain is collected from the drain inlet 28. It flows down into the device 5. By repeating such an operation cycle, the drain recovery device 5 recovers the drain generated in the heat exchange container 1.

The upper part of the heat exchange vessel 1 and the suction chamber 23 of the ejector 22 are communicated by a pipe 24. The ejector 22 sucks non-condensable gas such as air accumulated above the heat exchange container 1.

The inlet side of the ejector 22, that is, the suction chamber 23 side, is connected to the cooling fluid supply pipe 4 via the pump 15.
Further, the outlet side is connected to the coil-shaped cooling fluid supply pipe 11 by a pipe 25 and a check valve 37. Valve 2 is in line 25
The discharge pipe 27 provided with 6 is connected in series. An air vent line 20 provided with an automatic air vent valve 19 is connected to the inlet side of the coiled cooling fluid supply pipe 11. The cooling fluid supplied from the cooling fluid supply pipe 4 passes through the ejector 22 and passes through the suction chamber 23.
Then, a suction force is generated, and the non-condensable gas in the heat exchange container 1 is sucked, mixed with the cooling fluid, and sent to the coil-shaped cooling fluid supply pipe 11.

A steam supply pipe 2 provided on the upper side of the heat exchange vessel 1 is connected to an outlet side of a steam-using device such as a blower or a shrink tunnel (not shown) or a re-evaporation tank to exchange heat for condensing steam. Supply to container 1.

When heat exchange is started, air as non-condensable gas stays in the tank 1, and it is necessary to quickly remove this air in order to perform heat exchange efficiently. Accordingly, the steam is supplied from the steam supply pipe 2 into the tank 1 and the cooling fluid is supplied to the ejector 22 to generate a suction force, the valve 26 of the discharge pipe 27 is fully opened, and The accumulated air is quickly discharged out of the system.

As described above, by sucking and discharging the staying air by the ejector 22, the steam is simply supplied into the tank 1 and replaced with the staying air to be discharged out of the system.
The staying air can be reliably discharged from the system in a short time.

Heat exchange container 1 from which the initial accumulated air has been discharged
The inside is decompressed because the steam supplied from the steam supply pipe 2 is condensed by heat exchange to form a drain, and the volume thereof is rapidly reduced. The condensed drain flows down from the drain discharge pipe 3 to the drain recovery device 5. On the other hand, air as non-condensable gas mixed into the supplied steam is sucked into the ejector 22 by staying in the upper part of the heat exchange container.

The drain of the drain recovery device 5 and the air and the cooling fluid of the ejector 22 are mixed with each other to reach the coil-shaped cooling fluid supply pipe 11, exchange heat with steam to increase the temperature, and from the hot water recovery pipe 8. Collected at a predetermined collection point. As described above, by mixing the condensed drain and the cooling fluid and performing heat exchange, the temperature of the recovered hot water can be increased, and the heat recovery rate can be increased.

In the present embodiment, the non-condensable gas remaining in the vessel 1 during heat exchange can also be sucked by the ejector 22. In this case, the non-condensable gas sucked by the ejector 22 can be discharged out of the system from the automatic air vent valve 19 provided in the air vent line 20. However, when there is no problem even if non-condensable gas is mixed in the heat-exchanged hot water, it is not necessary to discharge the non-condensable gas out of the system by the automatic air release valve 19.

[0024]

According to the present invention, the mixed fluid of the drain pumped from the drain recovery device and the cooling fluid supplied from the ejector is heat-exchanged with steam in the heat exchange vessel to thereby recover the recovered fluid. The heat recovery rate can be improved by increasing the temperature.

Further, according to the present invention, by communicating the suction chamber of the ejector with the inside of the heat exchange container, the non-condensable gas such as air accumulated in the container during heat exchange is sucked by the ejector to the outside. Can be discharged.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a heat exchanger of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchange container 2 Steam supply pipe 3 Drain discharge pipe 4 Cooling fluid supply pipe 5 Drain recovery device 8 Hot water recovery pipe 19 Automatic air release valve 22 Ejector 23 Suction chamber 28 Drain inflow port 30 Drain reduction port 32 High pressure operation fluid introduction port 33 Equivalent Pressure port

Claims (1)

[Claims] 1. A drain recovery device for supplying steam and a cooling fluid to a heat exchange container and condensing the steam by exchanging heat with the cooling fluid, wherein the drain is recovered by pumping a drain to the bottom of the heat exchange container. To connect the drain reduction port of the drain recovery device to the heat exchange container, and to communicate the inside of the heat exchange container and the suction chamber of the ejector to connect the inlet side of the ejector to the cooling fluid supply source. A heat exchanger, wherein an outlet side of the ejector is connected to the heat exchange container.