JP5406001B2 - Latent heat recovery unit - Google Patents

Description

  The present invention relates to a hot water generator, and more particularly to a hot water generator equipped with a latent heat recovery heat exchanger that recovers the latent heat of exhaust gas from a combustion device and enables preheating of secondary hot water.

  Conventionally, in a hot water generator, in order to improve fuel efficiency, not only does the burner burn in the combustion chamber and the heat of combustion heats the heat transfer water and hot water on the secondary side, but also burns the burner. There has been a method of preheating the heat transfer water or the secondary hot water using the heat of the generated exhaust gas.

  For example, in order to effectively use the heat of combustion exhaust gas discharged from boilers, etc., a heat exchanger for recovering latent heat that absorbs not only sensible heat of combustion exhaust gas but also latent heat to increase the amount of heat absorption (Economizer) has been proposed (see, for example, Patent Document 1).

  When a conventional water heater using such a heat exchanger for collecting latent heat is used for hot water supply in a facility such as a public bath, for example, the configuration shown in FIG. 2 is often adopted.

  As shown in FIG. 2, the conventional hot water generator includes a combustion chamber 120 provided with a burner 110 and can accommodate a heat transfer water 200, and is accommodated in the hot water generator main body 100. The primary side circulation path 300 that circulates the heat transfer water 200, the secondary side circulation path 400 that circulates the secondary hot water 500 in the currant 410 provided for hot water supply, and the primary side circulation path 300 are circulated. The heat (sensible heat) of the exhaust gas 130 generated by the combustion of the indirect heat exchanger 600 that exchanges heat between the high-temperature heat transfer water 200 and the low-temperature secondary hot water 500 that circulates in the secondary-side circulation path 400 and the burner 110. , Latent heat recovery heat exchanger 700 for recovering latent heat). In the figure, the reference numeral 310 indicates a heat medium circulation pump provided in the primary side circulation path 300, the reference numeral 420 indicates a circulation pump provided in the secondary side circulation path 400, and a reference numeral 800. Shown is a flue that is communicatively coupled to the combustion chamber 120 via a latent heat recovery heat exchanger 700.

  The hot water generator configured as described above burns fuel such as gas and oil in the combustion chamber 120 by the burner 110 and heats the heat transfer water 200 accommodated in the hot water generator main body 100 by the combustion heat. Then, the high-temperature heat medium water 200 is circulated to the primary-side circulation path 300 by the heat-medium circulation pump 310, and similarly, the low-temperature secondary hot water 500 is circulated to the secondary-side circulation path 400 by the circulation pump 420. The secondary hot water 500 circulating through the secondary side circulation path 400 is heated by exchanging heat with the indirect heat exchanger 600.

  Further, as shown in the figure, the secondary hot water 500 circulating in the secondary side circulation path 400 is heat-exchanged with the latent heat recovery heat exchanger 700 before being supplied to the indirect heat exchanger 600 and heated. Is preheated. That is, in the conventional water heater, the latent heat recovery heat exchanger 700 is used to preheat the secondary hot water 500 circulating in the secondary side circulation path 400.

  Moreover, the hot water generator shown in FIG. 2 includes not only hot water supply but also a plurality of primary side circulation paths 300 and a plurality of indirect heat exchangers 600 and a plurality of secondary side circulation paths 400 corresponding thereto, for example, , Heating, circulation heating and the like can be performed simultaneously.

JP 11-248105 A

  The above-mentioned conventional hot water generator equipped with a heat exchanger for recovering latent heat can be said to be a very preferable configuration because it can effectively use the heat of combustion exhaust gas that was originally discarded, but the heat exchanger for recovering latent heat There are still many facilities that use hot water generators that do not have a.

  Even if it is desired to save energy by installing a heat exchanger for recovering latent heat, if the entire apparatus including the combustion device such as the hot water generator main body 100 is reconstructed, large-scale piping and flue modification are required. It is not easy because of the high cost.

  In addition, for example, in the case of a facility such as a public bath, it is necessary to always provide hot water at a predetermined temperature. Therefore, as shown in FIG. 2, the secondary hot water 500 circulating in the secondary side circulation path 400 is preheated. The secondary hot water 500 is always circulated in the secondary side circulation path 400.

  For this reason, when the usage frequency of the secondary hot water 500 supplied from the currant 410 decreases, the temperature of the secondary hot water 500 circulating in the secondary side circulation path 400 rises more than necessary, and the heat for latent heat recovery is increased. The high-temperature secondary hot water 500 enters the exchanger 700. In general, when the temperature of the secondary hot water 500 entering the latent heat recovery heat exchanger 700 becomes high, moisture condensation in the exhaust gas 130 is less likely to occur due to the characteristics of the latent heat recovery heat exchanger 700, resulting in latent heat recovery. There is a possibility that the efficiency of heat exchange in the heat exchanger 700 for use may decrease.

  Further, in the hot water generator for hot water supply, the amount and temperature of the secondary hot water 500 entering the latent heat recovery heat exchanger 700 vary depending on the opening / closing frequency of the currant 410, that is, the hot water supply frequency. The efficiency of heat exchange in the latent heat recovery heat exchanger 700 also varies. Furthermore, since the heat exchange capacity of the latent heat recovery heat exchanger 700 depends on the amount and temperature of the secondary hot water 500 circulating in the secondary side circulation path 400, for example, when the amount of the secondary hot water 500 circulating is small. When the start / stop control of the circulation pump 420 is performed, if the heat transfer is not sufficient, the heat of the exhaust gas 130 may cause the inside of the latent heat recovery heat exchanger 700 to be overheated or the pressure may increase.

  The present invention solves the above-described problems, prevents the heater efficiency of the latent heat recovery heat exchanger from being lowered and prevents an overheating state, and easily installs the latent heat recovery heat exchanger in an existing hot water supply device. It aims to provide the technology that has been made possible.

  In the present invention, the following means have been taken in order to solve the above problems.

  (1) The hot water generator main body that stores the heat transfer water, the combustion chamber that heats the heat transfer medium in the hot water generator main body, and the heat transfer water stored in the hot water generator main body are heat-exchanged. A latent heat recovery unit that can be attached to a hot water generator that circulates secondary hot water, and that can be connected to the combustion chamber and exhaust gas discharged from the combustion chamber. The flue structure to be discharged to the outside and the secondary side circulation path are configured independently, and the primary side circulation path for circulating the heat transfer water and the combustion chamber are discharged from the flue structure. A heat exchanger for latent heat recovery that recovers the latent heat of the exhaust gas by exchanging heat between the passing exhaust gas and the heat transfer water in the primary side circulation path, and the heat transfer water circulating through the primary side circulation path And an indirect heat exchanger for exchanging heat between the secondary hot water circulating in the secondary side circulation path and a predetermined case It was that are housed disposed.

  (2) The latent heat recovery unit according to (1), wherein the latent heat recovery unit can be attached to a hot water generator having a plurality of the secondary side circulation paths, and the secondary side circulation path is disposed in the casing. The same number of indirect heat exchangers are accommodated and arranged.

  (3) The latent heat recovery unit according to (1) or (2) is characterized by comprising an open cylinder that absorbs expansion and contraction due to a temperature change of the heat transfer medium circulating in the primary side circulation path.

  (4) The latent heat recovery unit according to any one of (1) to (3) above, further comprising a neutralizing device for neutralizing acidic drain generated by the latent heat recovery of exhaust gas by the latent heat recovery heat exchanger. To do.

  (5) In the latent heat recovery unit of (1) to (4) above, a plurality of temperature sensors for measuring the temperature of the exhaust gas before and after passing through the latent heat recovery heat exchanger include the flue structure. It is characterized by being provided in.

  According to the present invention, it is possible to add a latent heat recovery unit including a latent heat recovery heat exchanger to an existing hot water generator that is not provided with a latent heat recovery heat exchanger, and the latent heat recovery unit includes: Since the temperature of the heat transfer water supplied to the latent heat recovery heat exchanger can be set to a relatively low temperature, the heat exchange efficiency can be increased, and an open cylinder is provided for the latent heat recovery heat exchanger. Since overheating and pressure rise can be prevented, a hot water generator including a latent heat recovery unit with excellent safety can be obtained.

It is a schematic block diagram which shows the warm water generator of one Embodiment of this invention. It is a schematic block diagram which shows the conventional warm water generator provided with the heat exchanger for latent heat collection | recovery.

  Hereinafter, a latent heat recovery unit according to an embodiment of the present invention will be specifically described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a hot water generator 10 according to the present embodiment.

  In addition, the hot water generator 10 in this embodiment provided with this latent heat recovery unit can be suitably used for hot water supply and heating in a building, a factory, or a public bath facility, for example, but hot water supply and heating are required. It can be installed anywhere.

  As shown in FIG. 1, the hot water generator 10 according to the present embodiment includes a combustion chamber 13 provided with a burner device 12 and a heat exchanger 16 attached to the hot water generator, and a decompression steam chamber 11a and a heat transfer water. The hot water generator main body 11 composed of the heat transfer water storage chamber 11b that can accommodate the hot water, the flue 15 for exhausting the exhaust gas discharged from the combustion chamber 13 to the outside, and the hot water terminal provided for hot water supply A plurality of secondary circulation paths 30 that circulate the secondary hot water discharged from each of the currans 32, a latent heat recovery unit 90 that is a main part of the present embodiment and will be described in detail later. It is set as the structure which comprises.

  The latent heat recovery unit 90 includes a primary side circulation path 20 configured independently of the secondary side circulation path 30, a heat transfer water circulating through the primary side circulation path 20, and the secondary side circulation path 30. An indirect heat exchanger 50 for exchanging heat with the circulating secondary hot water and an existing flue 15 are provided so that exhaust gas generated by the combustion of the burner device 12 can pass through the casing 91 without hindrance. A flue structure 70 for leading to the existing flue 15 and a latent heat recovery heat exchanger 40 for recovering the heat (sensible heat, latent heat) of the exhaust gas passing through the flue structure 70, The casing 91 is housed and arranged in a predetermined shape.

  The latent heat recovery unit 90 is generated by the recovery of the latent heat of the exhaust gas by the open cylinder 22 that absorbs expansion and contraction due to the temperature change of the heat transfer water circulating in the primary-side circulation path 20 and the latent heat recovery heat exchanger 40. Neutralizing device 23 for neutralizing acidic drain, and two exhaust gas temperatures for measuring the exhaust gas temperature before and after the exhaust gas passing through the flue structure 70 passes through the latent heat recovery heat exchanger. Temperature sensors 41, 41.

  That is, the hot water generator 10 according to the present embodiment includes a latent heat recovery unit 90 including a heat exchanger 40 for recovering latent heat, and the heat of exhaust gas discharged from the combustion chamber 13 by the latent heat recovery unit 90 (latent heat and By efficiently recovering the sensible heat) and preheating the secondary hot water circulating through the secondary side circulation path 30, the amount of heat discharged from the flue 15 is recovered to reduce fuel.

  Further, the latent heat recovery unit 90 is a heat transfer water that circulates the latent heat of the exhaust gas passing through the flue structure 70 through the primary side circulation path 20 provided in the latent heat recovery unit 90 by the latent heat recovery heat exchanger 40. The heat transfer water circulating in the primary side circulation path 20 and the secondary hot water circulating in the secondary side circulation path 30 are heat-exchanged by the indirect heat exchanger 50 and circulated in the secondary side circulation path 30. A primary circulation system for heating secondary hot water is used.

  That is, the secondary hot water discharged from the currant 32 is a secondary hot water having a normal temperature (that is, a relatively low-temperature water) supplied from a water source (not shown) to the secondary side circulation path 30. Hot water generation using heat transfer water stored in the hot water generator body 11 as a heat source after heat exchange with the high-temperature heat transfer water circulating through the primary side circulation path 20 by the indirect heat exchanger 50 and preheating. Heated by the machine-attached heat exchanger 16 and supplied as secondary hot water at a predetermined temperature.

  Further, as shown in the drawing, the latent heat recovery unit 90 includes a flue structure 70 through which exhaust gas passes, a latent heat recovery heat exchanger 40 provided in the flue structure 70, and the interior of the latent heat recovery unit 90. A plurality of primary circulation paths 20 for circulating the heat transfer water, a plurality of indirect heat exchangers 50, and a plurality of secondary sides for supplying secondary hot water from the outside to the indirect heat exchanger 50 and discharging to the outside The circulation path 30 is housed in a casing 91 to form a unit.

  For this reason, the secondary hot water circulating through the plurality of secondary circulation paths 30 is supplied to the casing 91 to the plurality of secondary circulation paths 30 inside the latent heat recovery unit 90, and is supplied by the plurality of indirect heat exchangers 50. Secondary side connection portions 30 a are provided for discharging the secondary hot water after heat exchange and preheating to a plurality of secondary side circulation paths 30 outside the latent heat recovery unit 90.

  The casing 91 has a flue 15 prepared for disposing the combustion chamber 13 and the existing flue 15 of the hot water generator main body 11 or the latent heat recovery unit 90, and a flue structure inside the casing 91. A flue connection portion 15 a for connecting to 70 is provided. Exhaust gas discharged from the combustion chamber 13 of the hot water generator main body 11 is supplied to the flue structure 70 in the casing 91 through the flue connection portion 15a and passes through the flue structure 70 to recover latent heat. The exhaust gas after the heat is recovered by the heat exchanger 40 can be exhausted to the flue 15 installed outside the casing 91.

  In addition, the secondary side connection part 30a provided in the casing 91 of the latent heat recovery unit 90 employs a connection device that can be easily connected to piping or the like constituting the external secondary side circulation path 30, and the flue connection part 15a. Similarly, it is desirable to employ a connecting device that can be easily connected to the flue 15 of the exhaust gas discharged from the combustion chamber 13. Thereby, the retrofitting operation | work of the latent heat recovery unit 90 with respect to the existing hot water generator 10 etc. which does not have the heat exchanger 40 for latent heat recovery can be simplified.

  Moreover, in this embodiment, the circuit comprised by the primary side circulation path 20, the indirect heat exchanger 50, and the secondary side circulation path 30 is, for example, a plurality of sets of circuits having different purposes for hot water supply and heating ( For example, it is configured to include a hot water supply circuit, a heating circuit, and the like. Since each circuit has basically the same configuration, in the following description, a hot water supply circuit composed of a secondary side circulation path 30 having a set of primary side circulation path 20, indirect heat exchanger 50 and currant 32 will be described. To do.

  A combustion chamber 13 is provided in the heat medium water storage chamber 11 b in the hot water generator main body 11, and a burner device 12 is attached to one end side of the combustion chamber 13 so that the burner port faces the combustion chamber 13. The other end side is connected to the base end of the cylinder that is connected to the flue structure 70 of the latent heat recovery unit 90 and forms a part of the flue 15. Note that the cylinder may be a part of a flue disposed before the latent heat recovery unit 90 is retrofitted. Then, heat stored in the heat transfer water storage chamber 11b in the hot water generator main body 11 by the combustion heat obtained by burning the predetermined fuel (for example, gas, oil, etc.) in the combustion chamber 13 by the burner device 12. Warm water.

  In the latent heat recovery unit 90 according to the present embodiment, the latent heat recovery heat exchanger 40 is disposed on the combustion chamber side of the flue structure 70 connected to the combustion chamber 13 so that the high-temperature exhaust gas is used for recovering latent heat. It passes through the heat exchanger 40. The exhaust gas whose heat has been recovered by the latent heat recovery heat exchanger 40 is discharged to the outside from the flue 15 connected to the flue structure 70 in communication. That is, the latent heat recovery heat exchanger 40 is configured such that the heat transfer water circulating in the primary-side circulation path 20 and the exhaust gas after burning a predetermined fuel (for example, gas or oil) in the combustion chamber 13 The heat transfer water circulating through the primary-side circulation path 20 is heated by heat exchange, and the primary-side circulation-type hot water generator 10 is realized.

  The latent heat recovery heat exchanger 40 and the indirect heat exchanger 50 that perform the heat exchange described above are well known and will not be described. As a result of the heat exchange performed using the latent heat recovery heat exchanger 40, moisture in the exhaust gas is condensed and acidic drain is generated. However, the latent heat recovery unit 90 is provided with a neutralizer 23. The acidic drain discharged from the latent heat recovery heat exchanger 40 is treated by the neutralizing device 23 and then discharged to the outside of the hot water generator 10.

  A primary side circulation pump 21 is disposed in the primary side circulation path 20 inside the latent heat recovery unit 90. The primary-side circulation pump 21 supplies a relatively high-temperature heat transfer water heated by exchanging heat with the latent heat recovery heat exchanger 40 to the indirect heat exchanger 50, so that the heat transfer water and the secondary side In order to perform heat exchange with the secondary hot water circulating in the circulation path 30, the heat medium in the primary side circulation path 20 is circulated.

  An open cylinder 22 is provided in the primary side circulation path 20. The open cylinder 22 has a function as a device that absorbs expansion and contraction due to a temperature change of the heat transfer water circulating through the primary side circulation path 20, and by using the open type open cylinder 22 in this way, Since the latent heat recovery unit 90 including the latent heat recovery heat exchanger 40 does not correspond to the first type pressure vessel, the handling of the hot water generator 10 in this embodiment is not limited to a dedicated qualified person.

  The heat transfer water circulating in the primary side circulation path 20 is heated by collecting the heat of the high-temperature exhaust gas in the latent heat recovery heat exchanger 40, and circulates in the secondary side circulation path 30 in the indirect heat exchanger 50. Exchange heat with secondary hot water. Then, the heat transfer water whose temperature has been reduced by exchanging heat with the secondary hot water is again heated by the heat exchanger 40 for recovering latent heat and then supplied to the indirect heat exchanger 50 again. That is, the heat transfer water circulating in the primary side circulation path 20 inside the latent heat recovery unit 90 increases in temperature due to heat exchange with the exhaust gas in the latent heat recovery heat exchanger 40, and 2 in the indirect heat exchanger 50. The primary side circulation path 20 is circulated while repeating a decrease in temperature due to heat exchange with the secondary hot water circulating in the secondary circulation pump 31.

  A water supply pipe 60 provided with a water supply valve 61 is connected to the primary side circulation path 20. This is for automatically replenishing the heat transfer water circulating in the primary side circulation path 20. That is, in the plurality of circuits in the latent heat recovery unit 90, when the amount of the heat transfer water circulating through the primary side circulation path 20 decreases due to natural evaporation or the like, the water supply valve 61 of the water supply pipe 60 is opened and the water supply pipe is opened. The amount of heat transfer water circulating in the primary side circulation path 20 is kept constant by replenishing the heat transfer medium water from 60 to the primary side circulation path 20.

  The flue structure 70 of the latent heat recovery unit 90 is provided with two temperature sensors 41, 41 for measuring the temperature of the exhaust gas before and after passing through the latent heat recovery heat exchanger 40. It has been. Then, by detecting that the temperature of the exhaust gas measured by the temperature sensors 41, 41 has risen above a predetermined temperature, the cleaning time of the latent heat recovery heat exchanger 40 can be predicted.

  On the other hand, the secondary side circulation path 30 is provided with a secondary side circulation pump 31 for circulating the secondary hot water. The secondary hot water circulated in the secondary side circulation path 30 by the secondary side circulation pump 31 is supplied to the indirect heat exchanger 50 in the latent heat recovery unit 90, and the heat transfer water circulating in the primary side circulation path 20 After being preheated by heat exchange, the heat is discharged from the latent heat recovery unit 90.

  The secondary hot water after being preheated by the indirect heat exchanger 50 in the latent heat recovery unit 90 circulates through the secondary side circulation path 30 and is attached to the hot water generator main body 11 and attached to the hot water generator main body 11. Heat exchange with 16 and further heating.

  The hot water generator main body 11 in this embodiment forms a decompression steam chamber 11a and a heat medium water storage chamber 11b by enclosing the heat medium water in a can body having an internal pressure equal to or lower than atmospheric pressure, and also uses the heat medium water. A heating burner device 12 is connected to the combustion chamber 13, and a heat exchanger 16 attached to the hot water generator for taking out heat is disposed in the decompression steam chamber 11 a, and secondary by steam generated in the can body. The secondary hot water circulating in the side circulation path 30 is heated.

  That is, the secondary hot water circulating in the secondary side circulation path 30 is preheated by exchanging heat with the heat transfer medium circulating in the primary side circulation path 20 by the indirect heat exchanger 50 of the latent heat recovery unit 90, and then further heated. Then, heat is exchanged with the heat exchanger 16 attached to the hot water generator main body 11 and further heated, and hot water is supplied from a currant 32 disposed in the secondary side circulation path 30.

  Further, the secondary side circulation path 30 is provided with a water supply port (not shown) for replenishing secondary hot water supplied from the currant 32, and always has a predetermined amount of water in the secondary side circulation path 30. Secondary hot water is circulated.

  As described above, in the present embodiment, the relatively high-temperature heat transfer water heated by the latent heat recovery heat exchanger 40 of the latent heat recovery unit 90 is circulated through the plurality of primary-side circulation paths 20. The indirect heat exchanger 50 is supplied. On the other hand, the relatively low temperature secondary hot water for hot water supply is circulated through a plurality of secondary side circulation paths 30 that are piped independently from the primary side circulation path 20 in the latent heat recovery unit 90. It is supplied to the indirect heat exchanger 50. And it is set as the structure which heat-exchanges in each indirect heat exchanger 50, and preheats the secondary hot water which circulates through the some secondary side circulation path 30. FIG.

  Then, the heat transfer water of the primary side circulation path 20, whose temperature has been reduced by exchanging heat with the secondary hot water in the secondary side circulation path 30, exchanges heat with the exhaust gas in the latent heat recovery heat exchanger 40. It is warmed again. As described above, the hot water generator 10 according to the present embodiment uses the latent heat recovery heat exchanger 40 in order to heat the heat transfer water circulating through the primary side circulation path 20.

  As described above, according to the above-described embodiment, the latent heat recovery unit 90 includes the plurality of indirect heat exchangers 50, the plurality of primary circulation paths 20, the plurality of secondary circulation paths 30, and the latent heat recovery heat exchanger. 40 is arranged in an independent circuit in which casings 91 and the like are housed in a casing 91. Therefore, even in an existing hot water generator in which no latent heat recovery heat exchanger 40 is installed, the minimum piping work is performed. The latent heat recovery unit 90 can be retrofitted by remodeling the flue 15 or the flue 15, and the latent heat recovery can effectively improve the fuel consumption by recovering the heat of the high-temperature exhaust gas that has been thrown away until now. It can be set as the warm water generator 10 which comprises the unit 90. FIG.

  In addition, the heat transfer water circulating in the primary side circulation path 20 in the latent heat recovery unit 90 is heat-exchanged by the secondary hot water circulating in the plurality of secondary side circulation paths 30 by the plurality of indirect heat exchangers 50. Since the temperature is lowered, a relatively stable low-temperature heat transfer water can be provided to the latent heat recovery heat exchanger 40. Thereby, while preventing the overheat state and pressure rise inside the latent heat recovery heat exchanger 40, the latent heat recovery heat exchanger 40 can perform efficient heat exchange.

  Further, in the latent heat recovery unit 90, the primary side circulation path 20 and the secondary side circulation path 30 are separated inside the indirect heat exchanger 50, and therefore, the secondary hot water circulating through the secondary side circulation path 30. The scale component or the like does not enter the heat transfer water circulating through the primary side circulation path 20. For this reason, overheating due to adhesion of scale components and the like does not occur inside the latent heat recovery heat exchanger 40, and corrosion and the like do not occur.

  Further, since the latent heat recovery unit 90 includes the open cylinder 22, the latent heat recovery unit 90 absorbs expansion and contraction due to a temperature change of the heat transfer water circulating through the primary side circulation path 20. Thus, by using the open type open cylinder 22, the latent heat recovery heat exchanger 40 does not correspond to the first type pressure vessel.

  In addition, since the latent heat recovery unit 90 includes the neutralization device 23, the acidic drain discharged from the latent heat recovery heat exchanger 40 is treated by the neutralization device 23 and then discharged to the outside of the hot water generator 10. To do. This prevents sewage and rivers from being contaminated by acidic drainage.

  Note that if the latent heat recovery unit 90 is newly attached to an existing hot water generator, the temperature of the exhaust gas decreases due to heat exchange by the latent heat recovery heat exchanger 40, so that the draft of the flue structure 70 is insufficient and the exhaust gas is exhausted. Gas emissions may stagnate. In this case, exhaust gas exhaust fan is forcibly discharged from the flue structure 70 to the flue 15 by providing an exhaust fan for the flue structure 70, etc. it can.

  Further, even when the hot water generator 10 is newly installed, since the latent heat recovery unit 90 is made independent, for example, it is easy to cope with a failure of an element constituting the latent heat recovery unit 90 or to replace parts.

  From the embodiment described above, the hot water generator 10 including the following latent heat recovery unit 90 can be realized.

(1) Hot water generator main body 11 that stores the heat transfer water, the combustion chamber 13 that heats the heat transfer medium in the hot water generator main body 11, and heat exchange with the heat transfer water stored in the hot water generator main body 11. A latent heat recovery unit 90 that can be attached to a hot water generator 10 that circulates the secondary hot water that has been circulated, can be connected to the combustion chamber 13, and can be connected to the combustion chamber 13. The flue structure 70 that discharges exhaust gas to the outside and the secondary side circulation path 30 are configured independently, and are discharged from the primary side circulation path 20 that circulates heat transfer water and the combustion chamber 13. The heat exchanger 40 for recovering latent heat that recovers the latent heat of the exhaust gas by exchanging heat between the exhaust gas passing through the flue structure 70 and the heat transfer water in the primary circulation path 20 and the primary side Heat exchange between the heat transfer water circulating in the circulation path 20 and the secondary hot water circulating in the secondary circulation path 30 is performed. Latent heat recovery unit 90 and the indirect heat exchanger 50, but are housed arranged in a predetermined casing.

  With this configuration, for example, with respect to the existing hot water generator 10 that does not include the latent heat recovery heat exchanger 40, the high-temperature heat of the exhaust gas can be efficiently recovered with the minimum piping work and the modification of the flue 15. The latent heat recovery unit 90 can be installed, and the heat from the exhaust gas is effectively used to improve the fuel consumption, and reduce the carbon dioxide and prevent the greenhouse effect. It can be.

(2) A latent heat recovery unit 90 which can be attached to the hot water generator 10 having a plurality of secondary side circulation paths 30, and the same number as the number of secondary side circulation paths in the casing constituting the latent heat recovery unit 90. A latent heat recovery unit 90 in which the indirect heat exchanger 50 is accommodated.

  With this configuration, the heat transfer water circulating through the primary circulation path 20 is efficiently heat-exchanged with the secondary hot water circulating through the plurality of secondary circulation paths 30 by the plurality of indirect heat exchangers 50, and 1 Since the temperature of the heat transfer water supplied to the latent heat recovery heat exchanger 40 through the secondary side circulation path 20 can be lowered, the efficiency of heat exchange within the latent heat recovery heat exchanger 40 is improved. be able to.

  (3) The latent heat recovery unit 90 including the open cylinder 22 that absorbs expansion and contraction due to temperature change of the heat transfer water circulating in the primary side circulation path 20.

  With this configuration, since the open-type open cylinder 22 is used as a device that absorbs expansion and contraction due to temperature change of the heat transfer water circulating in the primary-side circulation path 20, the latent heat recovery unit 90 that does not correspond to the first type pressure vessel is used. It can be set as the warm water generator 10 comprised.

  (4) A latent heat recovery unit 90 including a neutralizing device 23 for neutralizing acidic drain generated by the latent heat recovery of exhaust gas by the latent heat recovery heat exchanger 40.

  With this configuration, since the acidic drain generated by the latent heat recovery heat exchanger 40 can be discharged after being neutralized, the hot water generator provided with the environmentally friendly latent heat recovery unit 90 that does not destroy the natural environment. 10 can be used.

  (5) A latent heat recovery unit 90 provided with a plurality of temperature sensors 41 and 41 in the flue structure 70 for measuring the temperature of exhaust gas before and after passing through the latent heat recovery heat exchanger 40.

  With this configuration, since it is possible to know a decrease in the efficiency of heat exchange by the latent heat recovery heat exchanger 40, it is easy to predict the cleaning time of the latent heat recovery heat exchanger 40 provided in the latent heat recovery unit 90. be able to.

  In addition, in this embodiment, although demonstrated using the warm water generator 10 which comprises the latent heat recovery unit 90 which heats water (heat-medium water) as heat-medium water, this invention is not limited to this. For example, the present invention can be applied to exhaust heat recovery of a gas engine and other devices that generate high-temperature exhaust gas.

  Although the embodiments have been described above, the specific configuration of the present invention is not limited to the above-described embodiments, and design changes and the like within a scope not departing from the gist of the invention are included in the present invention.

DESCRIPTION OF SYMBOLS 10 Hot water generator 11 Hot water generator main body 12 Burner apparatus 13 Combustion chamber 15 Flue 16 Heat exchanger attached to hot water generator 20 Primary side circulation path 21 Primary side circulation pump 22 Open cylinder 23 Neutralization device 30 Secondary side circulation Path 31 Secondary circulation pump 32 Curan 40 Heat exchanger for latent heat recovery 41 Temperature sensor 50 Indirect heat exchanger 60 Water supply pipe 61 Water supply valve 70 Flue structure 90 Latent heat recovery unit 91 Casing

Claims (5)

A hot water generator main body for storing heat transfer water,
A combustion chamber for heating the heat transfer water in the hot water generator body;
A latent heat recovery unit that can be attached to a water heater comprising a secondary side circulation path that circulates secondary hot water that has been heat-exchanged with heat transfer water contained in the hot water generator body,
A flue structure that is communicably connected to the combustion chamber and exhausts exhaust gas discharged from the combustion chamber to the outside;
A primary side circulation path configured independently of the secondary side circulation path for circulating the heat transfer water;
A latent heat recovery heat exchanger for exchanging heat between the exhaust gas discharged from the combustion chamber and passing through the flue structure and the heat transfer water in the primary side circulation path to recover the latent heat of the exhaust gas; ,
An indirect heat exchanger that performs heat exchange between the heat transfer water circulating through the primary circuit and the secondary hot water circulating through the secondary circuit;
Is stored and arranged in a predetermined casing. A latent heat recovery unit that can be attached to a water heater having a plurality of secondary side circulation paths,
The latent heat recovery unit according to claim 1, wherein the same number of indirect heat exchangers as the number of the secondary circulation paths are accommodated in the casing.   The latent heat recovery unit according to claim 1, further comprising an open cylinder that absorbs expansion and contraction due to a temperature change of the heat transfer water circulating in the primary side circulation path.   The latent heat recovery unit according to any one of claims 1 to 3, further comprising a neutralizer that neutralizes acidic drain generated by the latent heat recovery of the exhaust gas by the latent heat recovery heat exchanger. .   5. The flue structure according to claim 1, wherein a plurality of temperature sensors for measuring the temperature of the exhaust gas before and after passing through the latent heat recovery heat exchanger are provided in the flue structure. The latent heat recovery unit according to Item.

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