JPS6155597A - Heat recovery device - Google Patents

Abstract

PURPOSE:To avoid the mixing between heating fluid and heated fluid and to inhibit the contamination of them by a method wherein a leakage of heating fluid and heated fluid or thermal medium is sensed by an increased or decreased amount of thermal medium in the closed container and a leakage at the thermal conduction part is sensed by a variation in state of the thermal medium. CONSTITUTION:Thermal medium is guided to a heat exchanger B by a pump 7 from a heat exchanger A through a pipe 5 from the thermal medium amount holding volume sensor part 8 and furthr circulated through the pipe 6. Then, the thermal medium is heated by the heating fluid in the pipe 3 at the heat exchanging part A, thereafter it is passed through the pipe 5 and guided to the heat exchanger B, gives heat to the heated medium in the pipe 4 and applied to the desired application. The holding volume of the thermal medium is sensed by a liquid level sensor 9 in the thermal medium holding volume sensor 8, thereby the flowing-out of the thermal medium or heating or flowing of the heated fluid can be detected. That is, in case that the liquid surface can be measured correctly, even a small amount of leakage can be detected in reference to a specific volume of the thermal medium on the basis of the temperature of the thermal medium and thus the circulation pump for the thermal medium is stopped, a pressure of the thermal medium is decreased, the mixing of the thermal medium into the heating fluid or heated fluid can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for transferring and recovering heat from a heating fluid to a heated fluid.

[Technical background]

In devices that recover heat from a heating fluid to a heated fluid, holes may form due to corrosion in the heat transfer portion, and mixing of the fluids may occur. If it is desired to avoid mixing of the two fluids as much as possible, a method is used in which a heating medium is interposed between the two fluids and heat is recovered via the heating medium. The type of heating medium is selected so that even if the heating medium should be mixed into the fluid to be heated or heated, it will not have a serious effect.

As an example, a case will be described in which hot spring water is used as a heating fluid and hot water supply water is used as a heated fluid. In devices that directly exchange heat between hot spring water and hot water supply via the heat transfer surface of a heat exchanger, if there are holes in the heat transfer surface of the heat exchanger due to corrosion etc., the hot water supply water may be contaminated by the hot spring water. The sex is great. Therefore, in order to increase safety, a heating medium (water is suitable in this case) is interposed between the hot spring water and the hot water supply, allowing heat exchange between the hot spring water and the heating medium and heat exchange between the heating medium and the hot water supply water. Let the exchange take place. In this case, even if there is a hole in the hot spring water area due to corrosion, direct contamination of the hot water supply can be avoided. Contamination of the hot water supply occurs only when there are holes in the hot spring water heat exchange section and the hot water supply heat exchange section at the same time, but in this case, pressure is also involved, and contamination occurs when the hot spring water pressure is higher than the hot spring water pressure. It is necessary to detect a leak when it occurs on either the hot water supply side or the hot spring water side. If left untreated, leakage may occur between the two, creating the possibility of contamination.

[Structure of the invention]

The present invention seals a heat medium in a closed container, and includes a heat exchange section A that heats the heat medium and a heat exchange section B that cools the heat medium, respectively, in one closed container, but in two separate closed containers. In the heat exchange section A, the heating medium in the closed container is heated by the heated fluid C from outside the closed container, and in the heat exchange section B, the heated heating medium is heated by the heated fluid C from outside the closed container. In a device that is configured to give heat and transfer and recover heat from a heating fluid C to a heating fluid DK, heating fluid C1
A heat recovery device configured to detect leakage of the heated fluid or heat medium, and further detect leakage of the heat transfer section based on a change in the state of the heat medium, and mix the heated fluid and the heated fluid. It is designed to avoid.

Next, the present invention will be explained in detail based on the drawings.

FIG. 1 is a schematic diagram of a heat recovery device that transfers heat in the form of sensible heat of a heating medium, in which reference numeral 1 denotes a heat exchanger, and 2 denotes a heat exchanger I.
I, 5 is piping for heated fluid from outside, 4 is piping for heated fluid from outside, 5゜6 is piping, 7 is pump for heat medium circulation, 8 is heat medium holding amount detection unit, 9 is liquid level Detector, 1o indicates a heating medium.

In the example shown in FIG. 1, the heat exchange section A and the heat exchange section B are each formed in the form of a separate closed container), and the heat exchange unit A and the heat exchange unit B are formed in the form of separate closed containers), and the heat exchange unit 7 uses a heat transfer medium and a heat medium holding amount detection unit 8 to a pump 7. The heat exchanger BK is led from part A through pipe 5, and is further circulated through pipe 6.

The heat medium is first heated in the heat exchange section A by the heating fluid flowing through the tube 3, and then passes through the tube 5 to the heat exchange section B.
This heats the heated fluid flowing through the pipe 4, and the heated fluid is used for a predetermined purpose.

By detecting the amount of the heating medium held by the creepage detector 9 in the heating medium holding amount detecting section 8, it is possible to know whether the heating medium is outflowing or the heating fluid or the fluid to be heated is flowing into the heating medium.

FIG. 2 shows an example in which heat exchange parts A and B75 are arranged in the same closed container, and the heat exchange part is provided above the heat medium retention amount detection part 8, which is similar to that shown in FIG. 1. Parts having the same functions as the apparatus are designated by the same reference numerals as in FIG. 1, with reference numeral 9' indicating a liquid level detector when the operation is stopped, 9'' indicating a liquid level detector during operation, and 11 indicating a vacuum pump.

The heat medium is transferred from the heat exchange section A to the heat exchange section B by the pump 71/c.
It is circulated through the pipe 6 and heated in the heat exchange section A.
'4p, the medium gives heat to the nuclear heating fluid in the heat exchange part B, and the outflow of the heating medium or the inflow of the heating fluid or the heated fluid into the heating medium is caused by the liquid in the heating medium holding amount detection part 8. One thing you can learn from the surface detector 9' is that it can be done.

Using the examples shown in Figures 1 and 2, if the liquid level can be measured accurately, even a small leakage can be achieved by taking into consideration the specific volume of the heating medium based on the temperature of the heating medium. It is possible to detect it. When an abnormal increase or decrease in the heat medium is detected, a fault alarm is issued (7) to notify the user of the abnormality (/'C), and in some cases, the system is brought to an emergency stop.

In particular, by stopping the circulation pump of the heating medium, the pressure of the heating medium is reduced and the mixing of the heating medium into the heating fluid or fluid to be heated can be prevented. By providing a vacuum pump in the medium container and reducing the pressure in the heating medium system, it is possible to prevent the heating medium from mixing into the heating fluid or the fluid to be heated.

On the other hand, as shown in FIG.
If the heating medium is located above the liquid level of the detection unit, two sets of liquid level detectors are required because the liquid level is different during operation and when the operation is stopped. In this case, the activation condition is that the liquid level during the stoppage is normal, and after activation, the liquid level will be monitored by the liquid level detector 9' during operation. In this method, by stopping the operation of the heat medium pump 7, all the heat medium in the heat exchange section falls into the heat medium retention amount detection section, and therefore the heat medium is mixed into the heating fluid or the fluid to be heated in the form of a liquid Ω. You can prevent it from happening.

FIG. 5 shows an example of a system in which a heating medium transfers heat in the form of latent heat, and parts having the same functions as those shown in FIG. 1 are designated by the same reference numerals. In the example shown in FIG. 5, the heat medium receives heat from the heating fluid guided to the pipe 3 inserted into the heat medium and evaporates, and when heated i>fl in the heat exchange section B, the wood is heated. The steam condenses. When the level of the heating medium is higher than a predetermined value, it indicates that the heating fluid or fluid to be heated has leaked into the heating medium, and when it is lower than the predetermined value, it indicates that the heating medium has leaked out.

Fig. 4 shows the same type as Fig. 3, but in particular the heat exchange part A has a spraying method on the heated fluid piping, and when an increase or decrease in the heat medium is detected, By stopping the spraying of the liquid, it is possible to stop the transfer of heat and prevent the liquid from flowing out. Note that the symbols have the same meanings as those in FIG. 5 or 2.

Even in the systems shown in FIGS. 3 and 4, contamination of the heating fluid or the fluid to be heated can be prevented by lowering the pressure inside the container using a vacuum pump or the like. Furthermore, it is safer to use a heating medium that has a saturated vapor pressure that is lower than the pressure of the fluid to be heated.

FIG. 5 conceptually shows an example in which waste heat fluid from a food plant is used as the heating fluid introduced into the heat exchanger section through pipe 5, and an absorption refrigerator generator is used as the heat exchanger section B. , 1 is a heat exchange part A, 3 is a heated fluid pipe, 7 is a pump, 9 is a liquid level detector, 10 is a heat medium, 12 is an absorption refrigerator, 13 is a generator, 14 is a food plant, 15. 16 indicates piping.

In the heat exchange section A, a heat medium is sprayed by a pump 7 onto a heated fluid pipe led from a food plant, the heat medium is evaporated, and the generated steam is led to a generator 16 through a pipe 15, The dilute absorption liquid (corresponding to the exchange section B) (corresponding to the heated fluid in the present invention) is given heat, and is condensed and returned through the pipe 16. With this configuration, even if a hole in the generator of an absorption refrigerator occurs due to corrosion, it can be immediately detected by monitoring the heating medium condition, and countermeasures can be taken. This can prevent contamination from entering the plant.

If the heat recovery system of the present invention is of the latent heat type as shown in Figs. 5 and 4, the heat recovery system needs to be completely sealed, but if it is of the sensible heat type, it is Unless the system is at low pressure, it is only necessary that the heating medium be enclosed in the system and not isolated from the atmosphere.

In addition, mixing of heating fluid or heated fluid into the heating medium can be detected by changes in heating medium components, changes in ion concentration, changes in electrical conductivity, changes in specific gravity, etc., so these detection methods should be used together. is preferred. That is, in the example shown in FIG.
By installing a change detection device in the heating medium component in the heating medium 10, if there is a leak due to absorption and dissolution, it becomes possible to immediately detect it. Depending on the device for detecting changes in heat medium components, it may be impossible to detect changes in the heat medium flowing out.

[Brief explanation of drawings]

Figure 1, Figure 2, #! FIG. 3, FIG. 4, and FIG. 5 are schematic flowcharts for explaining embodiments of the present invention. DESCRIPTION OF SYMBOLS 1... Heat exchange part A, 2... Heat exchange part B, 6... Heating M (, body piping, 4... Heated fluid piping, 7...
・Pump, 8... Heat medium holding amount detection unit, 9, 9',
9'...Liquid level detector, 10...Heating medium, 11...
Vacuum pump, 12... Absorption refrigerator, 15... Generator, 14... Food plant.

Claims (1)

[Claims] 1. A heating medium is sealed in a closed container, and in one closed container,
Alternatively, heat exchange part A for heating the heat medium and heat exchange part B for cooling the heat medium are provided in two sealed containers, respectively.
The heating medium in the sealed container is heated by the heating fluid C from outside the sealed container, and the heat of the heated heating medium is applied to the heated fluid D from the outside of the sealed container in the heat exchange section B. However, in a device that transfers and recovers heat from heating fluid C to heated fluid D, leakage of heating fluid C, heated fluid D, or heating medium may occur due to an increase or decrease in the amount of heating medium held in or flowing through a closed container. A heat recovery device configured to detect 2. Claim 1 in which an increase or decrease in the amount of heat medium held in or flowing through a closed container is detected by the liquid level of the heat medium
Heat recovery device as described in section. 3. A heating medium component change detection device is further installed to detect leakage of the heating fluid C, the heated fluid D, or the heating medium based on an increase or decrease in the heating medium and a change in the components, according to claim 1 or 2. Heat recovery equipment. 4. The heat recovery device according to claim 3, wherein the device for detecting changes in heat medium components is an electrical conductivity detector. 5. The heat exchange device according to any one of claims 1 to 4, wherein the heat medium liquid level detection section is provided below the heat exchange section A and the heat exchange section B.