JP2017075752A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger capable of preventing fouling of a heat transfer part.SOLUTION: A heat exchanger 100 includes a steam supply part 2 for supplying steam, a heat transfer pipe 3 for exchanging heat with the steam, and a washing part 4 for washing the heat transfer pipe with washing water. The heat exchanger cools the steam, and recovers heat of the steam as hot water. The washing part sprays the washing water to the heat transfer pipe from above the heat transfer pipe. At that time, the washing water sprayed to the heat transfer pipe washes away or dilutes a contaminant adhering to a surface of the heat transfer pipe. Accordingly, the heat transfer pipe is washed, and fouling can be suppressed.SELECTED DRAWING: Figure 1

Description

  The technology disclosed herein relates to a heat exchanger that exchanges heat with a fluid.

  For example, the heat exchanger described in Patent Document 1 includes a steam supply pipe that supplies steam and a cooling fluid pipe that serves as a heat transfer section that exchanges heat with the steam. A cooling fluid flows through the cooling fluid pipe. The steam supplied from the steam supply pipe is cooled by exchanging heat with the cooling fluid pipe. At this time, a part of the cooled vapor condenses into a liquid and adheres to the surface of the cooling fluid pipe.

JP 2010-117106 A

  When the condensate adheres to the surface of the heat transfer section in this way, the heat transfer section may be soiled. For example, when oil or a corrosive substance is contained in the steam, the heat transfer section may be corroded if left for a long time with the condensate attached to the surface of the heat transfer section.

  The technology disclosed herein has been made in view of such various points, and an object thereof is to prevent the heat transfer section from being contaminated.

  The heat exchanger disclosed herein includes a supply unit that supplies a fluid, a heat transfer unit that exchanges heat with the fluid, and a cleaning unit that cleans the heat transfer unit with a cleaning liquid. The “cleaning” here includes not only completely removing the adhered substance to the heat transfer section, but also partially removing the adhered substance or diluting the adhered substance.

  According to the heat exchanger, since the surface of the heat transfer section is cleaned with the cleaning liquid, it is possible to prevent the heat transfer section from being soiled.

FIG. 1 is a schematic longitudinal sectional view of a heat exchanger. FIG. 2 is a layout view of the cleaning unit viewed from above.

  Hereinafter, exemplary embodiments will be described in detail with reference to the drawings.

  FIG. 1 is a schematic longitudinal sectional view of a heat exchanger 100 according to an embodiment. FIG. 2 is a layout view of the cleaning unit 4 as viewed from above.

  The heat exchanger 100 includes a container 10, a steam supply unit 2 that supplies steam into the container 10, a heat transfer tube 3 that is accommodated in the container 10, in which cooling water flows and exchanges heat with steam. And a washing section 4 for washing the heat transfer tube by applying washing water to the heat transfer tube 3. The heat exchanger 100 exchanges heat between the steam and the cooling water, cools the steam, and recovers the heat of the steam as hot water.

  The container 10 has a peripheral wall 11 formed in a cylindrical shape, a ceiling portion 12, and a bottom portion 13. The lower part of the container 10 serves as a storage unit 18 for storing drainage generated by condensation of steam and washing water. Connected to the bottom portion 13 is a first discharge pipe 14 for discharging a liquid such as drain accumulated in the storage portion 18.

  At the center of the container 10, an air release pipe 15 extending along the axis of the container 10 is provided. The upper part of the air release pipe 15 extends through the ceiling 12 to the outside of the container 10 and is open to the atmosphere. The lower part of the atmosphere release pipe 15 extends to the vicinity of the bottom part 13 and opens downward. In addition, a gap is provided between the lower end of the atmosphere release pipe 15 and the bottom portion 13.

  In addition, an overflow pipe 16 is provided at the bottom 13 of the container 10 to discharge the drain accumulated in the container 10. The overflow pipe 16 passes through the bottom portion 13 and extends along the axis of the container 10. The overflow pipe 16 has a smaller diameter than the atmosphere release pipe 15 and enters the atmosphere release pipe 15 from the lower end of the atmosphere release pipe 15. The upper end of the overflow pipe 16 is positioned higher than the lower end of the atmosphere release pipe 15 and opens upward. A second discharge pipe 17 is connected to the lower end of the overflow pipe 16.

  Drain is accumulated in the reservoir 18 up to the height of the upper end of the overflow pipe 16. An amount of drain exceeding the upper end of the overflow pipe 16 is discharged to the second discharge pipe 17 through the overflow pipe 16.

  The steam supply unit 2 is provided in a relatively upper part of the container 10. A steam supply pipe 22 is connected to the steam supply unit 2. The steam supply pipe 22 is connected to, for example, an outlet side of a steam using device or a drain tank, and steam is supplied.

  The steam supply unit 2 is an example of a supply unit, and steam is an example of a fluid.

  The heat transfer tube 3 is formed in a coil shape so as to circulate around the atmosphere opening tube 15. A cooling water supply pipe 31 is connected to the lower end of the heat transfer pipe 3, and a cooling water discharge pipe 32 is connected to the upper end of the heat transfer pipe 3. The cooling water supplied from the cooling water supply pipe 31 flows through the heat transfer pipe 3 and is discharged from the cooling water discharge pipe 32. The cooling water recovers heat from the steam by exchanging heat with the steam when flowing through the heat transfer tube 3. The cooling water supply pipe 31 is provided with a first temperature sensor 30 that detects the temperature of the cooling water supplied to the heat transfer pipe 3. The cooling water discharge pipe 32 is provided with a second temperature sensor 33 that detects the temperature of the cooling water discharged from the heat transfer pipe 3.

  The heat transfer tube 3 is disposed above the storage portion 18 of the container 10, and the lower end portion of the heat transfer tube 3 is not immersed in the drain stored in the storage portion 18.

  The heat transfer tube 3 is an example of a heat transfer unit, and the cooling water is an example of a heat medium.

  The cleaning unit 4 includes a plurality of sprays 41, a cleaning water supply pipe 42 that supplies cleaning water to the sprays 41, an adjustment valve 43 that is provided in the cleaning water supply pipe 42 and adjusts the supply amount of cleaning water, and an adjustment valve And a control unit 44 for controlling 43.

  The spray 41 is provided in the container 10 and above the heat transfer tube 3. In the example of FIG. 2, four sprays 41 are provided. The four sprays 41 are arranged at equal intervals around the axis of the container 10. The spray 41 is configured to spray the wash water downward. FIG. 2 shows the sprayed washing water by a one-dot chain line.

  The control unit 44 is constituted by a processor and receives detection signals from the first sensor 30 and the second temperature sensor 33. The control unit 44 adjusts the adjustment valve 43, that is, the supply amount of cleaning water, based on the amount of heat recovered by the heat transfer tube 3, which is obtained from the detection results of the first sensor 30 and the second temperature sensor 33. For example, the control unit 44 includes a temperature of cooling water discharged from the heat transfer tube 3 (hereinafter referred to as “outlet temperature”), and a temperature of cooling water supplied to the heat transfer tube 3 (hereinafter referred to as “inlet temperature”). The degree of opening of the adjustment valve 43 is controlled so that the amount of cleaning water supplied decreases as the temperature difference decreases (the outlet temperature decreases only when the inlet temperature is substantially constant; the same applies hereinafter). Moreover, the control part 44 controls the opening degree of the adjustment valve 43 so that supply of washing water will be stopped, if the temperature difference of cooling water becomes below a predetermined value.

  Operation | movement of the heat exchanger 100 comprised in this way is demonstrated.

  In the heat transfer pipe 3, cooling water flows from the cooling water supply pipe 31 toward the cooling water discharge pipe 32. On the other hand, steam is supplied into the container 10 from the steam supply unit 2. The steam supplied into the container 10 is cooled and condensed by the heat transfer tube 3 to become drain. At this time, the heat of the steam is transmitted to the cooling water through the heat transfer tube 3 and is recovered by the cooling water. Therefore, the cooling water discharged from the cooling water discharge pipe 32 is warm water. The hot water discharged from the cooling water discharge pipe 32 can then be used for various purposes.

  The drain adheres to the surface of the heat transfer tube 3, travels along the surface of the heat transfer tube 3, or drops from the surface of the heat transfer tube 3, and accumulates in the storage unit 18 of the container 10. The drain accumulated in the storage unit 18 is normally discharged through the first discharge pipe 14. If there is too much drain accumulated in the reservoir 18, part of the drain is discharged from the overflow pipe 16.

  Further, when the pressure in the container 10 is increased by the steam in the container 10, the drain water level in the region outside the atmosphere opening pipe 15 is pushed down by the steam, and the drained water that has been pushed down passes through the atmosphere opening pipe 15. It is discharged from the overflow pipe 16 through. When the pressure in the container 10 further increases, the drain water level is pushed down to the vicinity of the lower end of the atmosphere opening pipe 15, and a part of the steam is released to the outside of the container 10 through the atmosphere opening pipe 15.

  In such an operation, drain adheres to the surface of the heat transfer tube 3. At this time, if oil or a corrosive substance (hereinafter referred to as “fouling substance”) is contained in the fluid supplied from the steam supply unit 2, the fouling substance adheres to the surface of the heat transfer tube 3. If the state continues, there is a possibility that the heat transfer tube 3 is soiled.

  On the other hand, the heat exchanger 100 is provided with a cleaning unit 4. The cleaning unit 4 sprays cleaning water onto the heat transfer tube 3 from above the heat transfer tube 3. The washing water sprayed on the heat transfer tube 3 is dropped along the surface of the heat transfer tube 3 or from the surface of the heat transfer tube 3. At this time, the washing water is used to wash away or dilute the fouling substances adhering to the surface of the heat transfer tube 3. Thereby, the heat exchanger tube 3 is wash | cleaned and contamination is suppressed.

  The washing water is stored in the storage unit 18 together with the fouling substance, and is discharged through the first discharge pipe 14 or the overflow pipe 16. As described above, the heat transfer tube 3 is disposed above the storage portion 18 of the container 10, and the lower end portion of the heat transfer tube 3 is prevented from being immersed in the stored drain, so that it is stored in the storage portion 18. Contamination of the heat transfer tube 3 due to the pollutant is also avoided.

  At this time, depending on the relationship between the temperature of the washing water and the temperature of the cooling water flowing through the heat transfer tube 3, the heat recovered from the steam can be taken away by the washing water. Therefore, when the temperature difference between the outlet temperature of the cooling water and the inlet temperature becomes small, the supply amount of the cleaning water is reduced by the control of the adjustment valve 43 by the control unit 44. Thereby, the contamination of the heat transfer tube 3 can be suppressed while securing the amount of heat to be recovered.

  As described above, the heat exchanger 100 includes the steam supply unit 2 (supply unit) that supplies steam (fluid), the heat transfer tube 3 (heat transfer unit) that exchanges heat with steam, and the heat transfer tube 3 with washing water ( And a cleaning unit 4 for cleaning with a cleaning liquid.

  According to this configuration, even if the fouling substance adheres to the surface of the heat transfer tube 3 together with the drain generated by the condensation of the steam, the fouling substance is washed by the cleaning unit 4. Thereby, the contamination of the heat exchanger tube 3 can be prevented. As a result, since it is not necessary to comprise the heat exchanger tube 3 with a material with high fouling resistance, the cost of the heat exchanger 100 can be reduced.

  The heat transfer tube 3 recovers heat from the steam, and the cleaning unit 4 adjusts the amount of cleaning water based on the amount of heat recovered by the heat transfer tube 3.

  That is, since the cleaning liquid can take heat from the cooling water flowing through the heat transfer tubes 3, when the amount of heat recovered by the heat transfer tubes 3 is small, the amount of cleaning water is reduced and the amount of heat recovered is ensured.

  More specifically, the heat transfer tube 3 has cooling water (heat medium) flowing therein, and the cleaning unit 4 adjusts the amount of cleaning water based on the temperature of the cooling water after heat exchange with steam.

  That is, the amount of heat recovered by the heat transfer tube 3 is determined based on the temperature of the cooling water.

  Further, the cleaning unit 4 sprays cleaning water onto the heat transfer tube 3.

  According to this configuration, cleaning water can be sprayed over a wide area of the heat transfer tube 3. As a result, the number of components (for example, spray 41) of cleaning part 4 can be reduced, and cost can be controlled.

<< Other Embodiments >>
As described above, the embodiment has been described as an example of the technique disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed. Moreover, it is also possible to combine each component demonstrated by the said embodiment and it can also be set as a new embodiment. In addition, among the components described in the attached drawings and detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to illustrate the technology. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  For example, the configuration of each element of the heat exchanger 100 is merely an example, and various configurations can be employed.

  The heat exchanger 100 employs the heat transfer tube 3 as a heat transfer unit, but is not limited thereto. The heat transfer tube 3 may not be coiled. Further, the heat transfer tube 3 may be a fin tube type. Furthermore, the heat transfer unit may be a heat sink or the like.

  Furthermore, the heat transfer tube 3 may be configured to be immersed in the drain of the storage unit 18. In addition, from the viewpoint of more effectively suppressing the contamination of the heat transfer tube 3, a configuration in which the heat transfer tube 3 is not immersed in the drain of the storage unit 18 as described above is preferable.

  Although the washing | cleaning part 4 has the spray 41, arbitrary structures can be employ | adopted if it is the structure which can apply | coat a washing | cleaning liquid to a heat-transfer part. For example, the cleaning unit 4 may be a pipe in which cleaning water circulates and a plurality of supply holes are formed. In this case, the cleaning water is dropped or injected from the plurality of supply holes onto the heat transfer tube 3. Further, the position of the cleaning unit 4 is not limited to the upper side of the heat transfer tube 3. The cleaning unit 4 may be configured to apply cleaning water from the side to the heat transfer tube 3. However, it is preferable to arrange the cleaning unit 4 above the heat transfer tube 3 from the viewpoint of evenly applying the cleaning water to the heat transfer tube 3.

  Further, although cleaning water is employed as the cleaning liquid, the present invention is not limited to this. A liquid other than water may be used as long as it can clean the fouling substance.

  The heat exchange 100 is configured to recover the heat of the steam, but the target for heat exchange is not limited to steam. For example, the heat exchanger may be configured to recover heat by exchanging heat with a liquid such as water. In that case, the steam supply unit 2 is replaced with a water (liquid) supply unit. The container 10 is supplied with relatively high temperature water. The hot water and the heat transfer tube 3 exchange heat, and the heat is recovered in the cooling water. The water supplied into the container 10 is stored in the storage unit 18 and discharged through the first discharge pipe 14 or the overflow pipe 16. In the case of this configuration, the capacity of the storage unit 18 can be expanded as compared with the case where the storage unit 18 stores drainage. For example, the upper end of the overflow pipe 16 is positioned at a higher position.

  As described above, the technique disclosed herein is useful for a heat exchanger that exchanges heat with a fluid.

100 Heat exchanger 2 Steam supply part (supply part)
3 Heat transfer tubes (heat transfer section)
4 Cleaning section

Claims (5)

A supply for supplying fluid;
A heat transfer section that exchanges heat with the fluid;
A heat exchanger comprising: a cleaning unit that cleans the heat transfer unit with a cleaning liquid. The heat exchanger according to claim 1,
The heat transfer section recovers heat from the fluid;
The heat exchanger adjusts the amount of the cleaning liquid based on the amount of heat recovered by the heat transfer unit. The heat exchanger according to claim 2,
The heat transfer part is a heat transfer tube in which a heat medium flows,
The said washing | cleaning part adjusts the quantity of the said washing | cleaning liquid based on the temperature of the said heat medium after heat-exchanging with the said fluid, The heat exchanger characterized by the above-mentioned. The heat exchanger according to any one of claims 1 to 3,
The said supply part supplies steam, The heat exchanger characterized by the above-mentioned. The heat exchanger according to any one of claims 1 to 4,
The said washing | cleaning part sprays the said washing | cleaning liquid on the said heat-transfer part, The heat exchanger characterized by the above-mentioned.

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