JP3176771U - Heat transfer tube and exhaust heat recovery system for exhaust heat recovery system - Google Patents

Abstract

An exhaust heat recovery system capable of increasing exhaust heat recovery efficiency is provided.
A heat transfer pipe for an exhaust heat recovery system, which is provided so as to be connectable between a water supply pipe and a distribution pipe and in which a liquid channel is formed, is formed by a plurality of conical spiral heat transfer sections. Constitute. Further, the heat transfer section is arranged so as to have a multiple structure concentrically in the radial direction. In addition, each upstream end and each downstream end of the first heat transfer unit to the fourth heat transfer unit, and the connection pipe 21, the water supply pipe, and the distribution pipe are connected and connected outside the casing 10.
[Selection] Figure 2

Description

  The present invention relates to an exhaust heat recovery system that recovers heat from exhaust gas of a combustion engine such as a simple boiler, a small boiler, and a garbage incineration facility.

  Conventionally, exhaust heat is collected and used in a combustion engine such as a garbage incinerator, a gas turbine, a simple boiler, and a waste incineration facility. There is also known an economizer in which a heat transfer tube is installed in a boiler flue and the boiler efficiency is increased by exhaust heat exhaust gas through the heat transfer tube (for example, Patent Document 1).

JP-A-8-159407

  As described above, exhaust heat recovery systems that recover heat from exhaust gas in order to use the heat of exhaust gas from small boilers, simple boilers, garbage incineration facilities, etc. for other purposes are known. In the heat recovery system, it is difficult to perform sufficient exhaust heat recovery, and low recovery efficiency has been a problem.

  An object of the present invention is to solve the problem of a conventional exhaust heat recovery system, and an object of the present invention is to provide an exhaust heat recovery system capable of improving the exhaust heat recovery efficiency.

  Inventions provided to solve the above problems are as follows.

The heat transfer tube for the exhaust heat recovery system of the first means of the present invention is:
It is provided so that it can be connected between the water supply piping and distribution piping,
A heat transfer tube for an exhaust heat recovery system in which a liquid flow path is formed, wherein the heat transfer tube includes a plurality of spiral heat transfer sections. It is.

  Since the present invention is provided with a plurality of spiral heat transfer portions as described above, the surface area of the heat transfer tube when disposed in a flue such as a boiler can be significantly increased. Therefore, the efficiency of heat recovery from the exhaust gas can be improved extremely high.

  The heat transfer tube for the exhaust heat recovery system of the second means of the present invention is the heat transfer tube for the exhaust heat recovery system of the first means described above, and the plurality of spiral heat transfer portions are A heat transfer tube for an exhaust heat recovery system, characterized in that it is formed in a conical spiral shape.

  By forming a conical spiral shape, the end of the heat transfer section on the large diameter side is upstream in the flue and the end of the heat transfer section on the small diameter side is downstream in the flue. By disposing, the exhaust gas that circulates can be swirled inside the small diameter portion toward the axial center of the flue as it goes downstream in the flue. Further, the exhaust gas discharged from the small diameter portion toward the distal end is discharged so as to diffuse from the outer periphery of the small diameter portion toward the inner peripheral surface of the flue. Therefore, exhaust gas can be evenly diffused by the inner and outer peripheral surfaces of the heat transfer section, and heat transfer from the exhaust gas to the heat transfer section can be made smoother, further improving the efficiency of heat recovery. Can be made.

  The heat transfer tube for the exhaust heat recovery system of the third means of the present invention is the heat transfer tube for the exhaust heat recovery system of the first means or the second means described above, and has a plurality of spiral shapes. A heat transfer tube for an exhaust heat recovery system, wherein the heat transfer section is disposed so as to have a multiple structure concentrically in the radial direction.

  A plurality of spiral heat transfer portions are arranged so as to have a multiple structure concentrically in the radial direction. Therefore, it becomes easy to shorten in the axial direction of a heat exchanger tube, and a heat exchanger tube and by extension, an exhaust heat recovery system incorporating this can be made compact. Further, by adopting a multiple structure, the arrangement positions of the heat transfer tubes in the radial direction in the flue are dispersed, and are arranged more evenly. Therefore, when it arrange | positions in the flue of the same magnitude | size, the waste gas which distribute | circulates the inside of a flue becomes easy to contact | connect a heat exchanger tube equally, and it becomes easy to improve the efficiency of heat recovery. Further, since the heat transfer tubes are arranged in a more dispersed manner in the flue, it becomes easy to more evenly disperse the exhaust gas in the flue. Therefore, it is possible to reduce the possibility that sludge or the like due to a decrease in the flow rate of the exhaust gas adheres to the heat transfer tube or the flue inner wall surface.

  Moreover, the heat transfer tube for the exhaust heat recovery system of the fourth means of the present invention is the heat transfer tube for the exhaust heat recovery system of any one of the first means to the third means described above, Each of the spiral heat transfer parts is a heat transfer pipe for an exhaust heat recovery system, wherein the heat transfer pipe is connected in parallel between the water supply pipe and the distribution pipe.

  By connecting each heat transfer part in parallel between the water supply pipe and the distribution pipe, it is possible to improve the efficiency of exhaust heat exchange in each heat transfer part and further improve the efficiency of heat recovery in the entire heat transfer pipe. it can.

  Further, a heat transfer tube for an exhaust heat recovery system according to a fifth means of the present invention is the heat transfer tube for an exhaust heat recovery system according to any one of the first means to the third means described above, wherein Each of the spiral heat transfer parts is a heat transfer pipe for an exhaust heat recovery system, which is connected in series between the water supply pipe and the distribution pipe.

  By connecting each heat transfer section in series between the water supply pipe and the distribution pipe, the fluid inside the heat transfer pipe can be obtained at a higher temperature.

  The exhaust heat recovery system of the sixth means of the present invention is provided with a heat transfer tube for the exhaust heat recovery system of any one of the first to fifth means described above. System.

  The exhaust heat recovery system of the seventh means of the present invention includes a water supply pipe connected to the upstream end of the heat transfer pipe, a distribution pipe connected to the downstream end of the heat transfer pipe, and the plurality The connecting pipe for connecting and connecting the heat transfer parts is connected to each heat transfer part outside the casing, and is an exhaust heat recovery system.

  As described above, regarding the pipes connected and connected to each heat transfer section, the part to be connected and connected is outside the casing, so that water leakage occurs in the casing even if water leaks from the connected part. Can not be.

  The heat transfer tube and the exhaust heat recovery system for the exhaust heat recovery system according to the present invention include a plurality of spiral heat transfer sections as described above, and can greatly increase the surface area of the heat transfer tube. Therefore, the efficiency of heat recovery from the exhaust gas can be improved extremely high.

It is a block diagram which occupies the outline | summary of the waste heat recovery system of this invention. It is a principal part enlarged view of the waste heat recovery system of FIG. It is a front view of the heat exchanger tube of this invention used for the waste heat recovery system of FIG. It is a front view of another heat exchanger tube of the present invention.

  A heat transfer tube and an exhaust heat recovery system for an exhaust heat recovery system of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the exhaust heat recovery system 100 of the present invention is used by being partially housed in a chimney structure 1 for exhausting exhaust gas of a combustion engine such as a boiler 70 to the outside. is there. The outline of the exhaust heat recovery system 100 will be described. The exhaust heat recovery system 100 includes a casing 10 constituting a part of the chimney structure 1, the casing 10 to the inside of the casing 10, and the casing 10 to the outside of the casing 10. And the inside becomes a liquid flow path, the liquid is introduced into the casing 10 from the outside of the casing 10, heat is received from the exhaust gas in the chimney structure 1, and the temperature of the liquid is raised. A heat transfer pipe 20 that can distribute water outside the casing 10, and a liquid introduction control means 30 that controls the introduction of the liquid into the casing 10 upstream of the insertion port 11 of the heat transfer pipe 20 into the casing 10. , Is provided. The heat transfer tube 20 of the present invention will be described later in detail.

  The casing 10 has an exhaust gas flowing therein, and is formed in a cylindrical shape so that the exhaust gas flows smoothly. The casing 10 is made of stainless steel and is made of a heat-resistant material in order to avoid the influence of high-temperature exhaust gas. Therefore, you may form with the steel pipe etc. of other materials besides stainless steel. In addition, the casing 10 has flanges 15 formed at both ends thereof, and is configured to be easily connected directly to the existing chimney 2. Moreover, since it is continuously provided by the flange 15, it is easy to remove at the time of maintenance such as cleaning of the inside of the casing 10, replacement of parts, and inspection, thereby facilitating maintenance work and cost reduction. . Further, it is desirable to install a heat insulating material such as rock wool on the outer peripheral surface of the casing 10 in order to increase the recovery efficiency of exhaust heat.

  An auxiliary casing 17 is attached between the downstream end of the casing 10 and the chimney 2. The auxiliary casing 17 is fastened and fixed with bolts by a flange 15 on the upper side of the casing 10 and a flange 15 provided in a horizontal portion of the chimney 2. By providing the auxiliary casing 17 on the upper side of the casing 10, it is possible to directly observe the inside of the casing 10 by removing only the auxiliary casing 17 without removing the casing 10. Therefore, maintenance such as inspection of the inside of the casing 10 and cleaning of the heat transfer tubes 20 stored therein can be easily performed. Such an auxiliary casing 17 can be attached to one side or both sides of the exhaust gas flow direction 80 of the casing 10. An inspection window 13 having a lid that can be opened and closed is provided on the side surface of the casing 10 so that the inside of the casing 10 can be inspected from the outside. A plurality of inspection windows 13 may be provided.

  In addition, the casing 10 is provided with a drain valve 14 for discharging water in the chimney structure 1 to the outside of the casing 10 on the lower side thereof. When exhaust gas is circulated in the chimney and exhaust heat recovery is performed, water droplets adhere to the heat transfer tube 20 and drop to accumulate moisture in the casing 10. However, such a drain valve 14 is provided. Thereby, the water | moisture content stored in the casing 10 can be discharged | emitted outside. Further, on the upstream side of the insertion port 11 of the heat transfer tube 20 into the casing 10, an electromagnetic valve, a flow meter, a thermometer (thermometer for measuring feed water temperature) 54, a valve for adjusting the flow rate of liquid, and the like are provided. It has been. In addition, the value obtained by multiplying the “recovered heat quantity per unit” by the difference between the “inlet water temperature” at the insertion port 11 and the “outlet water temperature” at the insertion port 12 is multiplied by the flow rate based on the numerical values measured by these means. "Total recovered heat".

  The liquid introduction control unit 30 can be configured by, for example, an electromagnetic valve 31, a valve 32, a control unit 33, and the like. The electromagnetic valve 31 is disposed in a water supply pipe 51 connected to the heat transfer pipe 20, and the flow of liquid into the heat transfer pipe 20 in the casing 10 can be controlled by opening and closing the electromagnetic valve 31. Further, the water supply pipe 51 is provided with a valve 32, and the amount of liquid flowing into the heat transfer tube 20 in the casing 10 can be adjusted by the opening / closing amount of the valve 32. These solenoid valves 31 and the like may be disposed in the heat transfer tube 20 in the vicinity of the insertion port 11 on the upstream side of the insertion port 11 into which the heat transfer tube 20 is inserted into the casing 10.

The chimney structure 1 is provided with water distribution temperature measuring means 40 for measuring the temperature of the liquid in the heat transfer tube 20 after being heated by passing through the casing 10. When the temperature of the liquid in the heat transfer tube 20 measured by the distribution temperature measuring means 40 is equal to or higher than a predetermined temperature, the introduction of the liquid into the casing 10 can be controlled. Examples of the water distribution temperature measuring means 40 include a temperature sensor. The temperature sensor is installed in the distribution pipe 50 connected to the heat transfer tube 20 on the downstream side near the insertion port 12 where the heat transfer tube 20 is inserted outside the casing 10. This temperature sensor may be installed in the heat transfer tube 20 near the insertion port 12. By installing at these positions, the temperature rise of the liquid in the casing 10 can be detected more accurately. In addition, please change from the distribution water that adjusts the temperature of the discharged liquid to the desired temperature with this distribution temperature measuring means 40.
be able to.

  The control unit 33 includes a control panel 35 including a computer having a CPU, a ROM, a RAM, a display unit, operation keys, and a storage device such as a magnetic disk and a flash memory. Moreover, the control part 33 is connected by the temperature sensor (distribution temperature measurement means 40), the solenoid valve 31, and the wiring 34, and these and the control part 33 are comprised so that communication is possible by an electrical signal. The control panel 35 itself may include a display unit and operation keys, and a personal computer (not shown) including a CPU, ROM, RAM, storage device, and the like may be connected to the control panel 35. In this case, the control panel 35 and a personal computer correspond to the control unit 33.

  And the control part 33 controls each part as follows, for example. When an electrical signal from the temperature sensor of the water distribution temperature measuring means 40 is input to the control unit 33 and the control unit 33 determines that the temperature measured by the temperature sensor is equal to or higher than a predetermined temperature, the electromagnetic valve 31 is opened. At the same time, the valve 32 is brought into an open state in which a predetermined amount of liquid flows. Thereby, the liquid of a predetermined | prescribed flow volume will flow in into the heat exchanger tube 20 in a flue. This inflow amount is such that the temperature measured by the temperature sensor downstream of the insertion / extraction port 12 of the liquid casing 10 in the heat transfer pipe 20 that receives and distributes the exhaust heat from the heat transfer pipe 20 is equal to or higher than a predetermined temperature (for example, 40 ° C.). It is adjusted by the control unit 33 so that If the liquid whose temperature has increased due to exhaust heat recovery has not reached a certain temperature, it is determined that the boiler 70 has stopped, and the control unit 33 closes the electromagnetic valve 31 to prevent the liquid from flowing in.

Further, the exhaust heat recovery system 100 of the present invention is provided with a storage tank 60 via an auxiliary tank 52 and a pressurizing pump 53 in this order on the downstream side of the insertion port 12 of the heat transfer tube 20 of the casing 10. The liquid heated in the chimney heat transfer pipe 20 flows through the distribution pipe 50, temporarily stored in the auxiliary tank 52, pressurized by the pressurizing pump 53, and introduced into the storage tank 60 as storage means. . The liquid can be distributed by pressurizing the liquid by the pressurizing pump 53, and the liquid whose temperature has been raised can be smoothly sent to the storage tank 60 even at a place away from the chimney structure 1 or at a high place. In addition, by installing the storage tank 60, there is no means for blocking the fluid between the chimney structure 1 and the auxiliary tank 52, and safety is ensured so that a pressure higher than a predetermined level is not applied.

  Next, the heat transfer tube 20 will be described. As described above, the heat transfer tube 20 is arranged in the casing 10 and configured to allow a liquid to flow therethrough, and performs heat exchange with the exhaust gas flowing in the flue via the liquid. Accordingly, the material is preferably a material having excellent heat conductivity and heat resistance, such as a stainless steel tube. Moreover, since it is formed in a spiral shape in order to improve the recovery efficiency of exhaust heat as will be described later, it is preferable that the copper tube has excellent workability. In this example, the diameter of the heat transfer tube 20 is 10 mm. However, the diameter is not limited thereto, and may be a different diameter depending on the ability of the boiler 70 and the like.

  As shown in FIG. 2, the heat transfer tube 20 includes four first heat transfer portions 22 a to fourth heat transfer portions 22 d formed in a substantially conical spiral shape. These first heat transfer part 22a to fourth heat transfer part 22d are connected in series by a connecting pipe 21 in order from the upstream side of the heat transfer pipe 20, that is, the insertion port 11 side. Specifically, as shown in FIG. 3, the downstream end 24a of the first heat transfer section 22a is connected to the upstream end 23b of the second heat transfer section 22b. Next, the downstream end 24b of the second heat transfer section 22b is connected in communication with the upstream end 23c of the third heat transfer section 22c. Similarly, the downstream end 24c of the third heat transfer section 22c is connected to the upstream end 23d of the fourth heat transfer section 22d. The upstream end 23c of the first heat transfer section 22a is connected to the water supply pipe 51 through a pipe, while the downstream end 24d of the fourth heat transfer section 22d is provided with a water distribution temperature measuring means 40. The distribution pipe 50 is connected in communication. As shown in FIG. 4, the upstream end portions 23 a to 23 d and the downstream end portions 24 a to 24 d of the first heat transfer section 22 a to the fourth heat transfer section 22 d, the connection pipe 21, the water supply pipe 51, and the distribution The outlet pipe 50 is connected and connected outside the casing 10. Thus, about the piping connected and connected with each heat-transfer part 22a-22d, even if a water leak arises from a connection part by making the part to connect and connect the exterior of the casing 10, in the casing 10 This prevents the water from leaking and prevents the fluid from accumulating in the casing 10.

  Further, as shown in FIGS. 2 and 3, the first heat transfer section 22 a to the fourth heat transfer section 22 d are arranged in a multiplex manner on the same axis as the other adjacent heat transfer sections. Yes. Specifically, the downstream half part of the first heat transfer part 22a is disposed at a position inserted into the upstream half part of the second heat transfer part 22b. The second heat transfer section 22b to the third heat transfer section 22d are sequentially arranged in the same manner.

  Thus, by forming each heat transfer part 22a-22d which comprises the heat exchanger tube 20, the surface area of the heat exchanger tube 20 can be increased markedly. Therefore, the efficiency of heat recovery from the exhaust gas can be improved extremely high. Further, the casing 10 is formed in a conical spiral shape, and in the casing 10, the end of the heat transfer section on the side having a large diameter is disposed upstream of the casing 10, and the end of the heat transfer section on the side having a small diameter is disposed in the casing 10. By disposing the exhaust gas in the downstream side of the chimney 2, the flowing exhaust gas goes to the downstream side of the chimney 2, toward the axial center of the chimney 2, inside the small-diameter portion on the downstream side of the heat transfer parts 22 a to 22 d. Can be swirled. Further, the exhaust gas discharged from the small diameter portion toward the distal end is discharged so as to diffuse from the outer periphery of the small diameter portion toward the inner peripheral surface of the chimney 2. Accordingly, the exhaust gas can be evenly diffused by the inner and outer peripheral surfaces of the heat transfer portions 22a to 22d, heat transfer from the exhaust gas to the heat transfer portions 22a to 22d can be made smoother, and the exhaust heat The recovery efficiency can be further improved. Further, the heat transfer tube 20 as a whole can be easily shortened in the axial direction, and the heat transfer tube 20 and thus the casing 10 can be made compact. Further, by adopting a multiple structure, the arrangement positions of the heat transfer tubes 20 in the radial direction in the casing 10 are dispersed, and are arranged more evenly. Therefore, when it arrange | positions in the casing 10 of the same magnitude | size, the waste gas which distribute | circulates the inside of the casing 10 becomes easy to contact | connect the heat exchanger tube 20 equally, and it becomes easy to improve the collection | recovery efficiency of waste heat. Moreover, by connecting the heat transfer portions 22a to 22d in series between the water supply pipe 51 and the distribution pipe, the fluid inside the heat transfer pipes 22a to 22d can be obtained at a higher temperature. Note that only the fourth heat transfer portion 22d on the most downstream side has a conical spiral, such as making the outer diameter of the small diameter portion larger than the outer diameters of the small diameter portions of the other first heat transfer portions 22a to 22c. The shape may be changed to another shape, and the “conical spiral shape” heat transfer section referred to in the present invention includes such various shapes of the conical spiral shape.

  Next, a heat transfer tube according to another embodiment will be described. FIG. 4 shows a heat transfer pipe 20 ′ in which the heat transfer portions 22 a to 22 d are connected in parallel to the water supply pipe 51 and the distribution pipe 50, unlike the heat transfer pipe 20 of the first embodiment. Specifically, the upstream end portions 23a to 23d of the first heat transfer portion 22a to the fourth heat transfer portion 22d are respectively connected to the water supply pipe 51, and each of the first heat transfer portion 22a to the fourth heat transfer portion 22d. The downstream ends 24a to 24d are connected to the distribution pipe 50, respectively. Thus, by connecting each heat-transfer part 22a-22d in parallel with respect to the water supply piping 51 and the distribution pipe 50, the exchange efficiency of the waste heat in each heat-transfer part 22a-22d is improved, and the heat exchanger tube 20 whole The efficiency of heat recovery can be further improved.

  The present invention is not limited to the embodiment described above, and various modifications can be made within the scope of the gist of the present invention. For example, in the above-described embodiment, the number of heat transfer units is four, but it can be changed to other numbers. The heat transfer tube of the first means includes one in which each heat transfer portion has a spiral shape other than the conical spiral shape, for example, a cylindrical spiral shape.

  The heat transfer pipe and exhaust heat recovery system of the exhaust heat recovery system of the present invention are widely used to utilize the exhaust heat of combustion engines such as hot water in bathrooms of accommodation facilities, etc., simple boilers, small boilers, garbage incinerators, etc. Can be used.

1: chimney structure, 2: chimney, 10: casing, 11: insertion port, 12: insertion port, 13: inspection window, 14: drain valve, 15: flange, 17: auxiliary casing, 20, 20 ′: heat transfer tube, 21: Connection piping, 22a-22d: 1st heat transfer part-4th heat transfer part, 23a-23d: Upstream end part, 24a-24d: Downstream end part, 30: Liquid introduction control means, 31: Solenoid valve, 32 : Valve, 33: control unit, 34: wiring, 35: control panel, 40: water distribution temperature measuring means, 50: distribution pipe, 51: water supply pipe, 52: auxiliary tank, 53: pressurization pump, 54; thermometer (Water temperature measurement thermometer), 60: storage tank, 70: boiler, 80: flow direction of exhaust gas, 100: exhaust heat recovery system.

Claims (7)

It is provided so that it can be connected between the water supply piping and distribution piping,
A heat transfer tube for an exhaust heat recovery system in which a liquid flow path is formed, wherein the heat transfer tube includes a plurality of spiral heat transfer sections. .   The heat transfer tube for an exhaust heat recovery system according to claim 1, wherein the plurality of spiral heat transfer portions are formed in a conical spiral shape.   The exhaust heat recovery system for an exhaust heat recovery system according to claim 1 or 2, wherein the plurality of spiral heat transfer parts are arranged so as to have a multiple structure concentrically in a radial direction thereof. Heat transfer tube.   The exhaust heat recovery system according to any one of claims 1 to 3, wherein each of the plurality of spiral heat transfer units is connected in parallel between the water supply pipe and the distribution pipe. Heat transfer tube.   The exhaust heat recovery system according to any one of claims 1 to 3, wherein each of the plurality of spiral heat transfer sections is connected in series between the water supply pipe and the distribution pipe. Heat transfer tube.   An exhaust heat recovery system comprising the heat transfer tube for the exhaust heat recovery system according to any one of claims 1 to 5. The water supply pipe connected and connected to the upstream end of the heat transfer pipe, the distribution pipe connected and connected to the downstream end of the heat transfer pipe, and the connection pipe connecting and connecting the plurality of heat transfer parts are the casing. The exhaust heat recovery system according to claim 6, wherein the exhaust heat recovery system is connected to and connected to each heat transfer unit outside.

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