KR101243698B1 - Condensing boiler system having double economizer - Google Patents

Abstract

PURPOSE: A boiler system with a double effect economizer is provided to improve collection efficiency of condensation latent heat and sensible heat of an exhaust gas by driving two of condensing economizers according to supplied water temperature and temperature of the inside of a hot water tank. CONSTITUTION: A boiler system with a double effect economizer comprises a main body(10) of a boiler, a free economizer(20), a hot water tank unit(40), a post economizer(34), a first valve(SV1), a second valve(SV2), a third valve(SV3), a fourth valve(SV4), a fifth valve(SV5), and a supplied water temperature sensor(17). The main body of the boiler comprises a combustion chamber, a water drum, and a burner(12). The free economizer includes a tube supplying supplied water to the water drum. The hot water tank unit comprises a hot water tank storing hot water and a circulation pump(18). The post economizer includes a SUS tub including an inlet port and an outlet port. The first valve and the second valve supply water supplied from outside to the free economizer and the post economizer. The third valve supplies the hot water to the post economizer. The fourth valve and the fifth valve are closed according to a control signal of a drain valve. The supplied water temperature sensor senses the temperature of the hot water supplied to the first valve and the second valve. [Reference numerals] (12) Burner; (19) Water supply tank; (40) Hot water tank; (50) Control unit

Description

Condensing boiler system having double economizer

The present invention relates to a boiler system capable of maximally recovering sensible heat and condensing latent heat of waste gas, and more particularly, by installing an economizer in double. It relates to a condensing boiler system having an extreme structure.

Typically, the boiler has a structure to maximize the thermal efficiency by absorbing the sensible and latent heat of exhaust gas as useful heat. Such a condensing boiler system and its control method are described in detail in the following patent document 1 "Condensing boiler system and its control method" invented and patented by the inventor.

In Patent Document 1, water is always supplied to a spherical tube or a sus tube installed inside an economizer (condensation heat exchanger), thereby providing sensible heat and condensing latent heat of waste gas. Disclosed is a condensing boiler system (condensing boiler system) having a structure that maximizes the thermal efficiency (maximum) recovery. Although the condensing boiler having such a structure has a high efficiency of 100% (based on low calorific value) theoretically at a water supply temperature of 15 ° C. or lower, the boiler is operating at 93 to 94% efficiency due to the high water supply temperature of the boiler.

That is, even though the cold water is always supplied to the inner tube of the economizer in order to recover the maximum amount of sensible heat and condensation of exhaust gas, it is about 6% to 7% lower than the theoretical value of 100%. It was operated with efficiency, so the operating efficiency was not close to 100%.

On the other hand, as an example of the perfusion boiler which raised the thermal efficiency, the "perfusion boiler which has an air preheating function" disclosed by following patent document 2 is mentioned. The perfusion boiler disclosed in the patent document 2 enables the preheating of the combustion air without a separate preheater, and at the same time, the fins, water pipes, duct connecting plates, etc., on the flue where the heat of combustion and exhaust gas move. This prevents overheating and high temperature oxidation, and is configured to extend the life of the boiler as well as thermal efficiency.

However, the condensing boiler disclosed in Patent Document 1 and the perfusion boiler disclosed in Patent Document 2 adopt a method of storing hot water, that is, water heated in a boiler body in a hot water tank, so that hot water is stored in a hot water tank. Because the burner of was heated to a high temperature continuously, a large amount of fuel was consumed, resulting in poor thermal efficiency.

Patent Document 1: Registered Patent No. 10-0607854 (registered July 26, 2006) Patent Document 2: Registered Patent No. 10-0675093 (registered on Jan. 22, 2007)

Accordingly, an object of the present invention is to provide a boiler system having a dual-use economizer and a control method thereof to recover the sensible heat and the latent heat of condensation of the boiler as almost 100%.

Another object of the present invention is to communicate two condensing economizer (STS tube) condensing economizer in series on a high temperature exhaust gas discharge passage, and according to the temperature of the water supply temperature and the hot water hot water tank The present invention provides a boiler system having a dual effect economizer capable of adaptively operating two condensing economizers to improve the recovery efficiency of sensible and latent heat of exhaust gas, and to optimize the use of hot water.

A boiler system having a dual effect economizer according to the present invention for achieving the above object is a combustion chamber having an exhaust gas discharge passage, a water drum formed around or in the combustion chamber, and a burner installed in the combustion chamber to generate a flame. A boiler body comprising a; Installed on the exhaust gas discharge passage having a tube for supplying water to the water drum therein, and recovers the sensible heat and the latent heat of condensation by heating the water flowing through the tube by the hot exhaust gas Pre-economizers; A hot water tank unit configured to be connected to a hot water tank storing hot water and an outlet of the hot water tank and pumping hot water stored in the hot water tank by a circulation control signal to circulate the hot water to a hot water supply; A post-economizer which has a inner tube having an inlet and an outlet therein and is in series communication with the pre-economizer and recovers the sensible heat and the latent heat of condensation by heating the water flowing into the thermotube by the hot exhaust gas. (post economizer); A third valve for opening and closing water supplied from outside to the pre-economizer and the post-economizer, and a third valve for supplying the hot water supply water to the post-economizer, respectively. Wow; Fourth and fifth valves, one side of which is connected to the outlet of the post-economizer and the other side of which is respectively connected to the inlet of the pre-economizer and the water inlet of the hot water tank, are alternately opened and closed according to a drain valve control signal. ; A water supply temperature sensor for detecting a water supply temperature of the water supply source water supplied to the first and second water supply valves; Opening and closing of the first to fifth valves such that the pre-economizer and the post-economizers heat the water supply source water through the first valve and the hot water supply water through the third valve when the detected water supply water is above a preset temperature. A control unit for controlling opening and closing of the first to fifth valves such that the pre-economizer and the post-economizers heat only the water supply water through the first valve and the second valve when the detected water supply water is below a preset temperature. It is characterized by the configuration.

Condensing boiler system having a dual-effect economizer according to another aspect of the present invention is a boiler comprising a combustion chamber having an exhaust gas discharge passage, a water drum formed in or around the combustion chamber and a burner installed in the combustion chamber to generate flame A main body; Installed on the exhaust gas discharge passage having a tube for supplying water to the water drum therein, and recovers the sensible heat and the latent heat of condensation by heating the water flowing through the tube by the hot exhaust gas Pre-economizer; A hot water tank in which hot water is stored, a hot water temperature sensor for detecting a hot water temperature of hot water in the hot water tank, and a hot water tank connected to an outlet of the hot water tank to circulate the hot water stored in the hot water tank by a circulation control signal. A hot water tank unit composed of a pump; A post-economizer which has a inner tube having an inlet and an outlet therein and is in series communication with the pre-economizer and recovers the sensible heat and the latent heat of condensation by heating the water flowing into the thermotube by the hot exhaust gas. Wow; A third valve for opening and closing water supplied from outside to the pre-economizer and the post-economizer, and a third valve for supplying the hot water supply water to the post-economizer, respectively. Wow; Fourth and fifth valves, one side of which is connected to the outlet of the post-economizer and the other side of which is respectively connected to the inlet of the pre-economizer and the water inlet of the hot water tank, are alternately opened and closed according to a drain valve control signal. ; When the sensed hot water supply temperature is lower than or equal to a preset temperature, opening and closing of the first to fifth valves is performed such that the pre-economizer and the post-economizers heat the water supply water through the first valve and the water supply water through the third valve, respectively. A control unit for controlling opening and closing of the first to fifth valves such that the pre-economizer and the post-economizers heat only the feed water through the first valve and the second valve when the detected hot water temperature is equal to or greater than a preset temperature. It is characterized by the configuration.

A condensing boiler system having a dual effect economizer according to another aspect of the present invention includes a combustion chamber having an exhaust gas discharge passage, a water drum formed around or within the combustion chamber, and a burner installed in the combustion chamber to generate flame. A boiler body; ; Installed on the exhaust gas discharge passage having a tube for supplying water to the water drum therein, and recovers the sensible heat and the latent heat of condensation by heating the water flowing through the tube by the hot exhaust gas Pre-economizer; A hot water tank in which hot water is stored, a hot water temperature sensor for detecting a hot water temperature of hot water in the hot water tank, and a hot water tank connected to an outlet of the hot water tank to circulate the hot water stored in the hot water tank by a circulation control signal. A hot water tank unit composed of a pump; A post-economizer which has a inner tube having an inlet and an outlet therein and is in series communication with the pre-economizer and recovers the sensible heat and the latent heat of condensation by heating the water flowing into the thermotube by the hot exhaust gas. Wow; A third valve for opening and closing water supplied from outside to the pre-economizer and the post-economizer, and a third valve for supplying the hot water supply water to the post-economizer, respectively. Wow; Fourth and fifth valves, one side of which is connected to the outlet of the post-economizer and the other side of which is respectively connected to the inlet of the pre-economizer and the water inlet of the hot water tank, are alternately opened and closed according to a drain valve control signal. ; A water supply temperature sensor for detecting a water supply temperature of the water supply source water supplied to the first and second water supply valves; The pre-economizer and the post-economizer through the first valve when the detected water supply source water is more than the first preset temperature or less than the second preset temperature according to the water supply / hot water supply mode and the third The opening and closing of the first to fifth valves are controlled to respectively heat the hot water supply water through the valve, and the pre-economizer when the detected water supply water supply is below a preset first temperature or the hot water supply temperature is above a preset second temperature. And the control unit for controlling the opening and closing of the first to fifth valves such that the post-economizers heat only the feed water through the first valve and the second valve.

And a switch for supplying a mode setting signal for setting the operation mode to the water supply mode and the hot water supply mode to the controller according to a user's selection.

The pre-economizer and the post-economizer is connected to a drain valve for draining the water filled in the inner tube located therein to the outside, the drain valve is characterized in that the opening and closing by the controller.

The first to fifth valves and the drain valve are characterized in that the solenoid valve (electric valve) that is opened and closed by an electrical signal.

The condensing boiler system having the dual-effect economizer configured as described above is driven by serially communicating two economizers on the exhaust gas discharge path of the boiler body, and the two economizers according to the hot water temperature in the hot water tank and the exhaust temperature of the exhaust gas. By selectively controlling the path of the fluid to recover the sensible heat and the latent heat of condensation of the exhaust gas, the thermal efficiency can be further improved by adapting to the operating condition of the boiler to supply water of low temperature to the economizer of a large surface area.

1 is a cross-sectional view of a condensing boiler system according to a preferred embodiment of the present invention.
FIG. 2 is a circuit diagram illustrating a passion mountain of the condensing boiler system shown in FIG. 1. FIG.
3 is a control flowchart of a condensing boiler system according to a preferred embodiment of the present invention.
Figure 4 is a cross-sectional view of the boiler system according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. It should be understood, however, that the invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It should be noted that the embodiments of the present invention described below are intended to sufficiently convey the spirit of the present invention to those skilled in the art.

1 and 2 are a block diagram of a condensing boiler system according to a preferred embodiment of the present invention and a circuit diagram illustrating a passion mountain thereof, and FIG. 3 is a control of the controller 50 shown in FIGS. 1 and 2. It is a figure which shows a procedure. The boiler system according to the first embodiment having such a configuration has described an example of a furnace-associated boiler, but as can be seen by the embodiments described below, the present invention is also applied to a perfusion boiler as it is.

Example 1

1 and 2, the condensing boiler body 10 according to a preferred embodiment of the present invention is a waste gas discharge passage (WGi) (where i is an integer of 1, 2, 3, etc., 1 ≠ 2 ≠ 3 ≠ 4), for example, a combustion chamber 5 having an association 11, a water drum 15 formed around the combustion chamber 5 and filled with water and an inlet of the combustion chamber 5. It includes a burner 12 installed to generate a flame. An air preheater 14, a pre-economizer 20, and a post-economizer 34 are formed in series communication between the discharge passage WG1 of the tube 11 and the discharge passage WG4 connected to the flue 32. It is.

The air preheater 14 preheats combustion air CA supplied from the outside by the sensible and latent heat of the exhaust gas on the discharge passage, and the combustion air preheated by the air preheater 14. Is supplied to the burner 12 by the rotation of the blower 16 installed in the lower part of the burner 12. At this time, it is well known that the blower 16 is composed of a flow-type electric motor, the rotational speed is controlled according to the load amount by the inverter (not shown) control.

In addition, each of the pre-economizer 20 and the post-economizer 34 heats the water flowing into the inlets (Wi1, Wi2) by the high-temperature exhaust gas and discharges them to the respective outlets (Wo1, Wo2). The tubes 22 and 36 are provided. In this case, since the heat tubes 22 and 36 are spirally formed to widen the contact area with the hot exhaust gas discharged to the exhaust gas discharge passage WGi, the heat tubes 22 and 36 are configured to use the sensible heat of the exhaust gas and the latent heat of condensation. , 36) can be easily recovered by the low temperature water flowing into.

The water drum 15 of the boiler body 10 includes a manual water supply valve V1 connected to a water supply tube WS for supplying the working water for operating the boiler, and a high temperature of the water drum 15. Steam discharge valve (V2) for discharging the steam of the is connected.

The water supply valve 18 of the water supply pipe WS has a water supply pump 18 operated by a predetermined control to supply water stored in the boiler feed water tank 19 to the inlet side of the water supply valve V1. It is connected. The operating principle of recovering the sensible heat of the exhaust gas and the latent heat of condensation by driving the water supply pump connected between the water supply tank and the inlet of the economizer (condensation heat exchanger) and the water supply valve connected between the outlet of the economizer and the water drum is detailed in Patent Document 1 above. Please refer to this.

The inlet (Wi1) of the tubing (22) in the pre-economizer 20 is connected to the feed water pump (18) through the first valve (SV1) that is opened and closed by a control signal, the outlet (Wo1) It is connected to the water supply pipe (WS), and a manual valve for discharging the water filled in the inside of the heat tube (22) is connected between the heat tube (22) and the bit (PIT).

Inlet Wi2 of the heat tube 36 installed inside the post-economizer 34 is connected to one side of the third and fifth valves SV3 and SV5, and second and fourth valves are provided at the outlet Woo2. One side of SV2, SV4 is connected. At this time, the other side of the third valve (SV3) is connected to the feed water pump 18, the other side of the fourth valve (SV4) is operated by the circulation pump control signal to supply the hot water supply water stored in the hot water tank (40) It is connected to the outlet of the pump circulating pump 44, the other side of the second valve (SV2) is connected to the inlet (Wi1) of the pre-economizer 20. Finally, the other side of the fourth valve (SV4) is connected to the hot water inlet of the hot water tank 40, and between the portion of the heat tube 36 and the external bit filthy water (filled in the heat tube 36) A sixth valve SV6 for draining water to the pit is connected.

The first valve SV1 to the sixth valve SV6 in the above configuration are all solenoid valves that are opened and closed by electrical valve control signals.

On the other hand, a water supply temperature sensor 17 for detecting a water supply temperature of the water supply source is connected to the connection pipe of one side of the water supply pump 18 and the first and third valves SV1 and SV3, and the hot water tank 40 ) Is connected to the hot water temperature sensor 42 for detecting the hot water temperature of the hot water supply water stored therein.

In FIG. 2, reference numeral 50 denotes a control unit that can be configured as a one-chip such as a microprocessor (MPU). In the internal memory area, ignition and combustion of the burner 12, rotation control of the flow motor constituting the blower 16, A program for pumping control of the feed water pump 18 and a program for controlling on / off (open / close) of the circulation pump 44 and the first valve SV1 to the sixth valve SV6 are masked. It is. The configuration and operation of the controller 50 to appropriately control the rotational speed of the induction motor of the blower 16, and the configuration and operation of the control of the water supply pump 18 are patented by the present applicant. The technique described in 0675094 (January 22, 2007) and Patent Document 1 can be applied.

In addition, the control unit 50 is on / off of the mode setting switch 51 connected between the ground and the input port, that is, the water supply temperature sensor 17 and the hot water tank 40 connected to the water supply line according to the automatic water supply / hot water supply mode The pre-economizer 20 and the post-economizer by reading the output of the hot water temperature sensor 42 which senses the hot water temperature and controlling the opening and closing of the first to sixth valves SV1 to SV6. Supplying water to the water drum 15 in the boiler body 10 while maximizing the heat-recovery of the exhaust gas discharged to the exhaust gas passage WGi through the 34, or supplying a large number of hot water supply water to the hot water tank 40 To operate. This operation will be described in more detail with reference to FIG. 3.

Before describing the operation of the dual effect economizer of the condensing boiler system having the dual effect economizer configured as shown in Figs. 1 and 2 with reference to Fig. 3, the feed water pump 18 is adapted to the water level of the water drum 15. It is assumed that normal temperature water of 10 ° C. to 15 ° C. is continuously supplied at a rotational speed to be supplied through the tubing 22, the valve V1b, and the water supply valve V4 of the pre-economizer 20.

[Action 1]

When the condensing boiler system configured as shown in FIGS. 1 and 2 is operated and the burner 12 is operated to heat the boiler body 10, the controller 50 determines that the boiler is initially operated in the process S1 of FIG. 3. In step S2, the output of the water supply temperature sensor 17 connected to the water supply line is read to determine whether the temperature of the water to be supplied is less than or equal to a predetermined temperature α. Here, the predetermined α ℃ is the optimum temperature of the boiler operating water, it means a temperature value of about 55 ℃.

If it is determined that the water supply temperature is less than or equal to α ° C. as a result of the search determination in step S2, the controller 50 may be connected to the first inlet Wi2, the outlet Wi2, and the drain ports of the post-economizer 34 in step S3. The fourth, fifth, and sixth valves SV1, SV4, SV5, and SV6 are all closed, and only the second valve SV2 and the third valve SV3 are controlled to be opened. That is, the opening and closing of the first to sixth valves SV1 to SV6 are controlled as shown in Table 1 below.

division 1st valve 2nd valve 3rd valve 4th valve 5th valve 6th valve Open / close Closed (closed) Open (open) Open (open) Closed (closed) Closed (closed) Closed (closed) Operation mode Rapid preheating water supply mode

When the first to sixth valves SV1 to SV6 maintain the closed or opened state as shown in [Table 1], the boiler operating water (water) discharged by pumping the feed water pump 18, that is, Only the feed water is supplied to the inlets Wi1 and Wi2 of the heat tubes 22 and 36 inside the pre-economizer 20 and the post-economizer 34. Therefore, when the water supply source water is supplied from the water supply pump 18 in the state where the opening and closing of the first to sixth valves SV1 to SV6 are controlled as shown in [Table 1] above, this is primarily performed by the post-economizer 34. It can be seen that after passing through the tubing 36 first, it is supplied to the water drum 15 in the boiler body 10 via the tubing 22 of the pre-economizer 20 as secondary. In this state, when the temperature of the exhaust gas discharged through the pipe 11 is increased by the operation of the burner 12, the heat tubes 22 and 36 inside the pre-economizer 20 and the post-economizer 34. The sensible heat of the exhaust gas and the latent heat of condensation are recovered by the operation of the high temperature exhaust gas in contact with the surface area. The sensible heat by recovering the sensible heat and the latent heat of condensation contained in the flue gas passages WG2 and WG3, respectively, by flowing normal temperature water to the heat tubes 22 and 36 in the two economizers 20 and 34 in series communication with each other by the above operation. And the heat recovery rate can be further increased by increasing the latent heat recovery area of condensation, that is, the surface area where the heat tube and the exhaust gas are in contact.

delete

In addition, the feed water supplied by the feed pump 18 is heated by the pre-economizer 20 and the post-economizer 34 tube tubes 22 and 36 in series communication on the exhaust gas discharge passage WGi. By supplying the water, the temperature of the feed water supplied to the water drum 15 of the boiler main body 10 can be quickly increased. Therefore, when the boiler is initially operated, the feed water is heated by the two pre-economizers 20 and the post-economizer 34 connected in series to increase the feed water of the boiler.

[Action 2]

In the state in which the boiler is operated under the control of the process S3 of FIG. 3, the controller 50 searches for the switching state of the mode setting switch 51 in the process S4 to determine whether the current operation mode is the hot water supply / water supply mode. Here, the hot water supply mode is an operation mode requiring a large amount of hot water, and is set when continuous hot water is used. If it is determined in step S4 that the current operation mode is the water supply mode, the controller 50 reads the output of the water supply temperature sensor 17 in step S5 to determine whether the temperature of the water supply source water is continuously lower than or equal to a preset temperature α ° C. do.

If it is determined in step S5 that the current feed water temperature is less than or equal to a predetermined temperature α ° C., the controller 50 quickly controls the closing and heating of the first valve SV1 to the sixth valve SV6 in step S6. After controlling to the preheating operation mode, the process jumps to S4. That is, the controller 50 stops the circulation pump 44 in step S6, controls the fourth and fifth valves SV4 and SV5 to close, and then controls the second valve SV2 and the third valve SV3. ), And close the first valve (SV1).

In other words, the first to sixth valves SV1 to SV6 are controlled as shown in Table 1 above, so that the third tube 36 of the post-economizer 34 and the pre-economizer 20 in series communication with the third tube 36 are connected in series. Boiler operation, which is supplied to the water drum 15 of the boiler body 10 by heating the feed water supplied from the feed pump 18 by the tube 22 as hot exhaust gas discharged to the exhaust gas discharge path WGi. Raise the temperature of the water.

[Action 3]

When the temperature of the water supply source water sensed by the water supply temperature sensor 17 by the continuous operation of the boiler rises above a predetermined temperature α ° C., the controller 50 controls the first valve SV1 to the sixth valve SV6 in step S7. ) Switch to the quick hot water operation mode and jumps to the step S4 described above. That is, the controller 50 opens the first valve SV1 in step S7 and then closes the second valve SV2 and the third valve SV3. Thereafter, the fifth valve SV5 to the sixth valve SV6 are opened and the circulation pump 44 is operated.

When the circulation pump 44 is operated, the controller 50 counts the time with an internal timer, and when 10 or 20 seconds elapses, the sixth valve SV6 is closed (closed). The hot water supply water supplied to the fifth valve SV5 by the circulation pump 44 by the above operation is connected to the tubing 36 in the post-economizer 34 and maintained open for about 10 seconds or 20 seconds. Sewage filled in the inside of the heat tube 36 in the post-economizer 34 is discharged into the bit by the sixth valve SV6.

When the set time has elapsed, that is, 10 seconds or 20 seconds, the controller 50 opens the fourth valve SV4 for the value and then closes the sixth valve SV6. As described above, when the first to sixth valves SV1 to SV6 are sequentially controlled in the normal preheating water supply operation mode in step S7, the first valve SV1 is finally used as the inlet Wi1 of the pre-economizer 20. Only the water supply raw water passing through is supplied, and only the hot water supply water stored in the hot water tank 40 is supplied to the inlet Wi2 of the post-economizer 34 by the circulation pump 44.

The pre-economizer 20 feeds water to the water drum 15 by raising the boiler feed water temperature by the high-temperature exhaust gas discharged from the feed water pump 18 to the discharge passage WG2. The economizer 34 heats the hot water supply water circulated by the circulation pump 44 by the high-temperature exhaust gas discharged into the exhaust gas passage WG3, and then, through the fourth valve SV4 connected to the outlet WO2. Supply to the hot water tank (40).

That is, each of the pre-economizer 20 and the post-economizer 34 heats the water supply source water supplied from the water supply pump 18 and the hot water supply source water supplied from the circulation pump 44 with a high temperature exhaust gas. 15) and increase the temperature of the water supply and hot water supply to the hot water tank (40). Accordingly, by the above operation, the pre-economizer 20 and the post-economizer 34 have a low temperature on the surface of the inner tube 24 and 36 and a high temperature exhausted on the exhaust gas discharge passage WGi. Exhaust gas is brought into contact with each other, and the sensible and latent heat of the exhaust gas is recovered by the development.

[Action 4]

If the mode switch 51 shown in FIG. 1 is in the "on (hot water mode)" state, the controller 50 determines that the current operation mode is the hot water mode in step S4 of FIG. 3, and the hot water tank in step S8. The output of the hot water temperature sensor 42 connected to 40 determines whether or not the hot water temperature is below a predetermined β. In the present invention, the predetermined β ℃ means a value of about 65 ℃ as the optimum temperature for the user to use hot water.

When it is determined that the water supply temperature of the process S8 is equal to or less than β ° C, the controller 50 controls the first valve SV1 to the sixth valve SV6 in the rapid hot water operation mode of process S7 in process S9. That is, the fourth and fifth valves SV4 and SV5 are closed, the fifth valve SV5 to the sixth valve SV6 are opened, and the circulation pump 44 is operated. When the circulation pump 44 is operated, the controller 50 counts the time with an internal timer, and when 10 or 20 seconds elapses, the sixth valve SV6 is closed (closed). The hot water supply water supplied to the fifth valve (SV5) by the circulation pump 44 by the above operation is connected to the heat tube 36 in the post-economizer 34 to maintain the open state for about 10 seconds or 20 seconds Sewage filled in the inside of the heat tube 36 in the post-economizer 34 is discharged into the bit by the sixth valve SV6.

In addition, when the set time has elapsed, that is, 10 seconds or 20 seconds, the controller 50 opens the fourth valve SV4 for the value and then closes the sixth valve SV6. As described above, when the first to sixth valves SV1 to SV6 are controlled in the rapid hot water supply mode in step S9, water supply source water passing through the first valve SV1 to the inlet Wi1 of the pre-economizer 20 is eventually. Only water is supplied, and only the hot water supply water stored in the hot water tank 40 is supplied to the inlet Wi2 of the post-economizer 34 by the circulation pump 44. That is, the post-economizer 34 may be used exclusively for hot water supply, and stably heat the hot water supply water to supply the hot water tank 40.

Therefore, the pre-economizer 20 raises the boiler feed water temperature by the high-temperature exhaust gas discharged from the feed water pump 18 to the discharge passage WG2 and feeds the water to the water drum 15. The post-economizer 34 heats the hot water supply water circulated by the circulation pump 44 by the high-temperature exhaust gas discharged into the exhaust gas passage WG3 and then connects the fourth valve SV4 connected to the outlet wo2. Supply to the hot water tank (40) through.

[Action 5]

If the same operation as the operation 4 is continued and the temperature of the hot water supply water filled in the hot water tank 40 is equal to or higher than the preset β ° C., the controller 50 detects it in step S8 and the circulating pump 44 in step S10. ) To stop the hot water supply mode. In addition, the control unit 50 controls the first valve (SV1) to the sixth valve (SV6) in the rapid hot water operation mode of the step S6 in step S10. That is, the controller 50 stops the circulation pump 44 in step S10, controls the fourth and fifth valves SV4 and SV5 to close, and then controls the second valve SV2 and the third valve SV3. ), And close the first valve (SV1).

When the closing of the first valve (SV1) to the sixth valve (SV6) is controlled as described above, the tube 24 of the pre-economizer 20 and the post tube 36 of the post-economizer 34 are connected in series. By maintaining the state connected in series, the water supply source water supplied from the water supply pump 18 as two economizers is heated as the high-temperature exhaust gas discharged to the exhaust gas discharge path WGi, and thus the water drum of the boiler body 10 ( 15) Increase the heat recovery rate by quickly raising the temperature of the boiler operating water supplied.

The condensing boiler system having the dual-effect economizer according to the above-described embodiment uses the pre-economizer 20 and the post-economizer 34 in the casing 22 and 36 connected in series on the exhaust gas discharge path as necessary. It can be used to heat the water supply and hot water supply independently, it is possible to increase the recovery rate of the sensible and latent heat of the exhaust gas to improve the thermal efficiency.

[Example 2]

Example 2 is to install and control the dual-effect economizer described above in the perfusion boiler, which will be described below with reference to FIG. 4 is a cross-sectional view of a boiler system according to a second embodiment of the present invention. In FIG. 4, reference numeral 10 denotes a boiler body wrapped with a thermal insulation case having a combustion chamber 5 formed therein, 12 burners, 13 air supply pipes, and 15A and 15 perpendicular to the combustion chamber 5 in the boiler body 10. It is a standing inner and outer water pipe. In addition, TV2 is a water supply pipe, TV1 is a steam transport pipe through which steam is discharged, A is an upper header, B is a lower header, and WG1 represents an exhaust gas discharge passage through which exhaust gas is discharged. For the operation of heating the boiler feed water supplied to the inner water pipe 15A and the outer water pipe 15B through the water supply pipe TV2 by the combustion operation of the perfusion boiler having such a structure, see the contents of Patent Document 2 above. Please.

The pre-economizer 20 and the post-economizer 34 are connected in series between the exhaust gas discharge passage WG1 of the perfusion boiler configured as shown in FIG. 4 and the flue 23 for discharging the exhaust gas to the outside. It is. The inlet (Wi1) and outlet (Wo1) and the inlet (Wi2) and outlet (Wo2) of the pre-economizer (20) of the pre-economizer 20 of the perfusion boiler as shown in Figure 4 to the perfusion boiler in the form shown in FIG. If applied as it is, the perfusion boiler can implement the same operation as the above-mentioned [Operation 1] to [Operation 5]. That is, a person skilled in the art who understands the technical idea of the present invention can easily change the furnace-tubular condensing boiler body 10 shown in FIG. 2 to the boiler body 10 of the perfusion boiler shown in FIG. 4.

5; Combustion chamber 10: boiler body
12 burner 14 air preheater
15: water drum 16: blower
17: water supply temperature sensor 18: feed water pump
20: pre-economizer 34: post economizer
40: hot water tank 42: hot water temperature sensor
50 Control part SV1 to SV6: Valve 1 to Valve 6

Claims (6)

A condensing boiler system having a dual effect economizer, comprising: a boiler body comprising a combustion chamber having an exhaust gas discharge passage, a water drum formed around or within the combustion chamber, and a burner installed in the combustion chamber to generate flame; Installed on the exhaust gas discharge passage having a tube for supplying water to the water drum therein, and recovers the sensible heat and the latent heat of condensation by heating the water flowing through the tube by the hot exhaust gas Pre-economizer; A hot water tank unit configured to include a hot water tank in which hot water is stored, and a circulation pump connected to an outlet of the hot water tank and pumping hot water stored in the hot water tank by a circulation control signal to circulate the hot water into hot water; A post-economizer which has a inner tube having an inlet and an outlet therein and is in series communication with the pre-economizer and recovers the sensible heat and the latent heat of condensation by heating the water flowing into the thermotube by the hot exhaust gas. Wow; A third valve for opening and closing water supplied from outside to the pre-economizer and the post-economizer, and a third valve for supplying the hot water supply water to the post-economizer, respectively. Wow; Fourth and fifth valves, one side of which is connected to the outlet of the post-economizer and the other side of which is respectively connected to the inlet of the pre-economizer and the water inlet of the hot water tank, are alternately opened and closed according to a drain valve control signal. ; A water supply temperature sensor for detecting a water supply temperature of the water supply source water supplied to the first and second water supply valves; Opening and closing of the first to fifth valves such that the pre-economizer and the post-economizers heat the water supply source water through the first valve and the hot water supply water through the third valve when the detected water supply water is above a preset temperature. A control unit for controlling opening and closing of the first to fifth valves such that the pre-economizer and the post-economizers heat only the water supply water through the first valve and the second valve when the detected water supply water is below a preset temperature. Condensing boiler system having a dual-effect economizer, characterized in that consisting of. A condensing boiler system having a dual effect economizer, comprising: a boiler body comprising a combustion chamber having an exhaust gas discharge passage, a water drum formed around or within the combustion chamber, and a burner installed in the combustion chamber to generate flame; ; Installed on the exhaust gas discharge passage having a tube for supplying water to the water drum therein, and recovers the sensible heat and the latent heat of condensation by heating the water flowing through the tube by the hot exhaust gas Pre-economizer; A hot water tank in which hot water is stored, a hot water temperature sensor for detecting a hot water temperature of hot water in the hot water tank, and a hot water tank connected to an outlet of the hot water tank to circulate the hot water stored in the hot water tank by a circulation control signal. A hot water tank unit composed of a pump; A post-economizer which has a inner tube having an inlet and an outlet therein and is in series communication with the pre-economizer and recovers the sensible heat and the latent heat of condensation by heating the water flowing into the thermotube by the hot exhaust gas. Wow; A third valve for opening and closing water supplied from outside to the pre-economizer and the post-economizer, and a third valve for supplying the hot water supply water to the post-economizer, respectively. Wow; Fourth and fifth valves, one side of which is connected to the outlet of the post-economizer and the other side of which is respectively connected to the inlet of the pre-economizer and the water inlet of the hot water tank, are alternately opened and closed according to a drain valve control signal. ; When the sensed hot water supply temperature is lower than or equal to a preset temperature, opening and closing of the first to fifth valves is performed such that the pre-economizer and the post-economizers heat the water supply water through the first valve and the water supply water through the third valve, respectively. A control unit for controlling opening and closing of the first to fifth valves such that the pre-economizer and the post-economizers heat only the feed water through the first valve and the second valve when the detected hot water temperature is equal to or greater than a preset temperature. Condensing boiler system having a dual-effect economizer, characterized in that consisting of. A condensing boiler system having a dual effect economizer, comprising: a boiler body comprising a combustion chamber having an exhaust gas discharge passage, a water drum formed around or within the combustion chamber, and a burner installed in the combustion chamber to generate flame; Installed on the exhaust gas discharge passage having a tube for supplying water to the water drum therein, and recovers the sensible heat and the latent heat of condensation by heating the water flowing through the tube by the hot exhaust gas Pre-economizer; A hot water tank in which hot water is stored, a hot water temperature sensor for detecting a hot water temperature of hot water in the hot water tank, and a hot water tank connected to an outlet of the hot water tank to circulate the hot water stored in the hot water tank by a circulation control signal. A hot water tank unit composed of a pump; A post-economizer which has a inner tube having an inlet and an outlet therein and is in series communication with the pre-economizer and recovers the sensible heat and the latent heat of condensation by heating the water flowing into the thermotube by the hot exhaust gas. Wow; A third valve for opening and closing water supplied from outside to the pre-economizer and the post-economizer, and a third valve for supplying the hot water supply water to the post-economizer, respectively. Wow; Fourth and fifth valves, one side of which is connected to the outlet of the post-economizer and the other side of which is respectively connected to the inlet of the pre-economizer and the water inlet of the hot water tank, are alternately opened and closed according to a drain valve control signal. ; A water supply temperature sensor for detecting a water supply temperature of the water supply source water supplied to the first and second water supply valves; The pre-economizer and the post-economizer through the first valve when the detected water supply source water is more than the first preset temperature or less than the second preset temperature according to the water supply / hot water supply mode and the third The opening and closing of the first to fifth valves are controlled to respectively heat the hot water supply water through the valve, and the pre-economizer when the detected water supply water supply is below a preset first temperature or the hot water supply temperature is above a preset second temperature. And a control unit configured to control opening and closing of the first to fifth valves such that the post-economizers heat only the feed water through the first and second valves. The method according to any one of claims 1 to 3, wherein the post-pre-economizer is connected to a drain valve for draining the water filled in the inner tube located inside the drain valve, characterized in that the drain valve is opened and closed by the control unit Condensing boiler system with dual effect economizer. The condensing boiler system of claim 4, wherein the first to fifth valves and the drain valve are electric valves that are opened and closed by an electrical signal. The condensing boiler system according to claim 4, wherein a switch for supplying a mode setting signal for setting an operation mode to a water supply mode and a hot water supply mode to the controller is further connected according to a user's selection.

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