JP2004286395A - Latent heat recovery type heat source machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a latent heat recovery type heat source machine capable of extending the operable time of equipment by taking note with the neutralizing capacity of drain and rapidly stopping the operation thereof in abnormality. <P>SOLUTION: This heat source machine 1 comprises a primary heat exchanger 5 and a secondary heat exchanger 7. Drain generated in the secondary heat exchanger 7 flows from a receiving pan 81, passes a drain pipe 83, is sent to a neutralizer 85 for neutralization, and is drained from a drain pipe 91. A pH detection unit 93 is fitted to the drain pipe 91. A pH detected by the unit 93 comes out of a specified safe range, a stop gas solenoid valve 21 in a gas supply pipe 17 is closed to stop the operation of the heat source machine 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a latent heat recovery type heat source device provided in a water heater, a bath water heater, a hot water heater and the like. In particular, the present invention relates to a heat source device in which the operable time of the device can be extended as much as possible and the operation can be stopped immediately in the event of an abnormality.
[0002]
[Prior art]
The latent heat recovery type heat source unit has high thermal efficiency, and is about to be widely used as a heat source of a hot water supply unit such as a water heater, a bath water heater, and a floor heater. This latent heat recovery type heat source device includes a heat exchanger (secondary heat exchanger) that recovers latent heat of water vapor in combustion exhaust gas generated by being heated by a burner. High thermal efficiency is obtained by the latent heat recovery in the secondary heat exchanger in addition to the radiant heat by the flame and the heat exchange by the combustion gas in the primary heat exchanger.
[0003]
In a secondary heat exchanger that recovers latent heat, water vapor in exhaust gas exchanges heat with water in the exchanger to condense into water and generate a drain. A trace amount of NO _X or SO _X contained in the combustion exhaust gas is dissolved in the drain, and exhibits a strong acidity with a pH of about 3. The drain cannot be drained directly because it does not conform to the Sewerage Law, which has a pH standard of 5.8 to 8.6. For this reason, the heat source device is provided with a neutralizer for neutralizing the drain with a neutralizing agent, and the drain is neutralized to an appropriate pH and then drained to the sewer. As the neutralizing agent, for example, granular calcium carbonate or the like is used.
[0004]
Meanwhile, the operation of the latent heat recovery type heat source device is stopped based on the remaining amount of the neutralizing agent. The remaining amount of the neutralizing agent is not actually measured, but is estimated from the integrated combustion amount obtained by integrating the amount of fuel sent to the burner. Then, when the accumulated combustion amount approaches the maximum value of the accumulated combustion amount and it is estimated that the remaining amount of the neutralizing agent is small, first, the fact is displayed on a remote controller or the like, and then it is estimated that the amount is further reduced. And stop the operation automatically.
[0005]
Actually, about 2.9 kg of the neutralizing agent is mounted on one heat source unit, and this amount is equivalent to 15 years of the neutralizing agent consumption estimated by the above-mentioned integrated combustion amount. is there. On the other hand, the life of the machine body is designed to be about 10 years. In other words, the amount of the neutralizing agent is set so as to have a sufficient margin for the life of the device body.
[0006]
[Problems to be solved by the invention]
The above-mentioned integrated combustion amount is obtained by integrating the gas input and the usage time. Here, the gas input is a value (100%) assuming full combustion (for example, a combustion state when a plurality of hot water taps are opened at a time). In the case of full combustion, the drainage amount of the drain naturally increases, and a corresponding amount of the neutralizing agent is used. However, in practice, the heat source unit is not always used for full combustion, and in many cases, only one hot water tap is opened, so the actual drainage drainage and the amount of neutralizer consumed are , Less than when full combustion is assumed.
On the other hand, the usage time is set to 3000 hours in one example. This time is approximately equivalent to the lifetime (10 years) of the above-described designed device (for example, about 8.2 years when used for one hour at full combustion per day).
[0007]
After all, the upper limit of the integrated combustion amount (100% × 3000 hr) has a considerable margin in terms of the combustion state and the use time, compared to the value based on the life of the equipment and the neutralization capacity of the neutralizer. It is set to have. Then, even if the accumulated combustion amount approaches the maximum value and the remaining amount of the neutralizing agent is estimated to be small, a considerable amount of the neutralizing agent actually remains, and operation is possible in terms of the neutralizing capacity of the drain. Even in the state, the device stops.
[0008]
The present invention has been made in view of the above problems, and has taken measures to increase the operable time of the device by focusing on the neutralization capability of the drain, and to quickly stop the operation in the event of an abnormality. An object of the present invention is to provide a latent heat recovery type heat source device.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, a heat source device of the present invention includes a burner that burns fuel, a heat exchanger that is heated by the burner, and that also recovers latent heat of water vapor in combustion exhaust gas generated by the burner. A drain water drainage system that neutralizes and drains a drain generated in the heat exchanger, and a control unit that controls each unit, a heat source device including:
A drain pH detection unit is provided downstream of the drain neutralizer disposed in the drain drainage system, and a signal regarding the pH of the drain after neutralization is sent from the unit to the control unit, When the value is out of a predetermined range, the burner is stopped from burning.
Shut down equipment despite a significant amount of neutralizing agent remaining to actually detect the pH of the drain drained after neutralization and determine if the neutralizer has neutralization capacity As a result, while the device body is operating normally, the device can be operated until the neutralization capability of the neutralizer actually disappears.
[0010]
In the present invention, it has an integrator for integrating the amount of fuel sent to the burner,
The remaining amount of the neutralizing agent in the neutralizer is predicted based on the integrated value of the integrator, and if the predicted remaining amount of the neutralizing agent is less than a certain amount, a letter or error to that effect is made. After the code is displayed, the burner combustion can be stopped when the pH detection unit signal is out of the range.
In the first stage, by displaying based on the accumulated combustion amount as before, it becomes easy to take the following measures such as calling a service person.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, description will be made with reference to the drawings.
First, a configuration example of a latent heat recovery type heat source device used as a water heater will be described.
FIG. 2 is a diagram schematically illustrating a configuration of a main body and a main piping system of the latent heat recovery type heat source device according to one embodiment of the present invention.
In the combustion chamber 3 of the heat source unit 1, a primary heat exchanger 5, a secondary heat exchanger (latent heat recovery heat exchanger) 7, a burner 9, a fan 11, and the like are provided. An exhaust port 13 is provided in an upper part of the combustion chamber 3. In the combustion chamber 3, the burner 9, the primary heat exchanger 5, the secondary heat exchanger 7, and the exhaust port 13 are arranged in this order in the blowing direction of the fan 11. The fan 11 is provided with a rotation speed sensor 15.
[0012]
Gas is supplied to the burner 9 from a gas supply source through a gas supply pipe 17. The gas supply pipe 17 is provided with a filter 19, an original gas solenoid valve 21, and a gas proportional valve 23 from the upstream side. Further, the burner 9 is provided with a gas solenoid valve 25 and two capacity switching gas solenoid valves 27. Either one or both of the capacity switching gas solenoid valves 27 are opened according to the hot water supply capacity, and the amount of gas supplied to the burner 9 is adjusted. The opening degree of the gas proportional valve 23 and the gas supply time (time during which the gas solenoid valve is open) are sent to a control unit (not shown).
[0013]
The burner 9 is provided with a spark plug 31, a burner sensor 33, and a frame rod 35. The ignition plug 31 is ignited by an ignition device 37 to burn the combustion gas supplied to the burner 9. When the flame rod 35 detects the flame, the ignition device 37 is stopped. The burner sensor 33 detects the combustion of the burner and detects the burn-out of the burner. A safety device such as an overheat prevention device 39 is provided near the burner 9.
[0014]
The hot water supply system includes a water supply pipe 51 extending from the water supply source to the combustion chamber 3, a hot water supply pipe 53 exiting from the combustion chamber 3 to a kitchen, a washroom, and a hot water tap of a bath. The water supply pipe 51 first passes through the secondary heat exchanger 7 in the combustion chamber 3 and once exits the combustion chamber 3. After passing through the primary heat exchanger 5 in the combustion chamber 3 again, it exits the combustion chamber 3 and is connected to the hot water supply pipe 53.
[0015]
The water supply pipe 51 is provided with a drain plug 55, a filter 57, a water amount sensor 59, and a water input thermistor 61 in this order from the upstream side. A drain plug 63 is provided in a portion after passing through the primary heat exchanger 7. The hot water supply pipe 53 is provided with a can body thermistor 65, a water amount adjustment valve 67, a hot water discharge thermistor 69, and a drain tap 71 in this order from the upstream side. The water supply pipe 51 and the hot water supply pipe 53 are bypassed by a bypass pipe 75 provided with a bypass water amount adjusting valve 73. Each thermistor and each valve are connected to a control unit (not shown). The control unit opens and closes the bypass water amount adjustment valve 73 and adjusts the mixing ratio of cold water and hot water so that the hot water temperature detected by the hot water thermistor 69 becomes an appropriate temperature. Further, the control unit adjusts the water amount adjusting valve and the drain plug so that the pressure in these pipes is appropriately maintained.
[0016]
Below the secondary heat exchanger 7 in the combustion chamber 3, a saucer 81 is attached. The receiving tray 81 communicates via a drain pipe (drain drainage system) 83 with a neutralizer 85 shown at the lower right of the figure. A water level electrode 87 for measuring the water level is provided on the upper part of the neutralizer 85, and a drain plug 89 is provided on the lower part. The outlet of the neutralizer 85 is connected to a drain pipe 91. The kind of the neutralizing agent may be the same as the conventional one, for example, calcium carbonate. The amount of the neutralizing agent can be reduced as compared with the conventional case.
[0017]
The drain pipe 91 is provided with a pH meter or a pH electrode (pH detection unit) 93, and measures the pH of the drain water discharged from the neutralizer 85. As the pH meter 93, an ordinary redox potentiometer type can be used. This type of pH meter detects a pH value by determining a potential difference between a glass electrode and a calomel electrode serving as a reference electrode. Also, a semiconductor type or the like can be used. The pH value detected by the pH meter 93 is sent to the control unit. Management of the pH value in the control unit will be described later.
[0018]
The start and stop of the device, setting of the desired hot water temperature, and the like are performed by a remote controller (not shown) connected to the control unit. The remote control is installed in an easy-to-operate kitchen or the like.
[0019]
Next, the latent heat recovery operation in the combustion chamber 3 will be described.
In the primary heat exchanger 5, a combustion gas is supplied to the burner 9, and the gas is ignited by a spark plug 31. At the same time, the combustion air is sent from the fan 11 and the gas burns, generating flame and combustion gas. The primary heat exchanger 5 is heated by the radiant heat of this flame and the combustion gas, and the medium to be heated (water) flowing in the pipe is heated. Thereafter, the combustion gas is sent by the fan 11 in the direction of the secondary heat exchanger 7 further upward. The combustion gas exchanges heat with water flowing in the secondary heat exchanger 7 to lower the temperature, and the water vapor in the combustion gas condenses into water. The combustion gas is then exhausted from the exhaust port 13.
[0020]
The water condensed with the water vapor in the combustion gas drops on the tray 81, and reaches the neutralizer 85 from the plate 81 through the drain pipe 83. Then, the water is neutralized to an appropriate pH by the neutralizer 85 and drained from the outlet to the drain pipe 91.
[0021]
On the other hand, the water supplied from the water supply pipe 51 first passes through the secondary heat exchanger 7, where it exchanges heat with the combustion gas and steam, and the temperature rises to some extent. Then, the warmed water passes through the primary heat exchanger 5, where it is heated by the radiant heat of the flame and the combustion gas and sent to the hot water supply pipe 53.
[0022]
Next, a processing method until the device is stopped based on the pH value of the drain will be described.
FIG. 1 is a flowchart showing processing when the operation of the heat source device according to the embodiment of the present invention is stopped.
First, at S1, the control unit calculates the integrated combustion amount as in the conventional case. The integrated combustion amount is obtained by multiplying the opening of the gas proportional valve by the operating time of the device. The upper limit value of the integrated combustion amount is, for example, a case where the opening degree of the gas proportional valve 23 is 100% and the usable time is 3000 hours. In S2, it is determined whether or not the integrated combustion amount has reached a first amount at which the remaining amount of the neutralizing agent is estimated to be somewhat lower. Here, the first amount is, for example, a case where the usable time reaches 20 hours remaining (that is, a case where the use time reaches 2980 hours) or the like. When it is determined that the accumulated combustion amount has reached the first amount and the remaining amount of the neutralizing agent is not more than a certain level, in S3, the remote controller informs the remote controller of the first stage of stopping the device by a character (for example, “neutralizing agent”). Is reduced. ") Or an error code (for example, lighting of a predetermined lamp). However, in this case, the operation of the device can be continued because the neutralizing agent remains.
[0023]
While the operation of the device is continued, it is determined in S4 whether the integrated combustion amount has reached a second amount in which the remaining amount of the neutralizing agent is estimated to be zero. Here, the second amount is a time when the use time has reached the usable time of 3000 hours. Then, in step S5, the remote controller indicates that the device is in the second stage of stopping the device by characters (for example, "Please contact a service person.") Or error codes (for example, blinking of a predetermined lamp). However, in this case, as described above, the amount of the neutralizing agent has a considerable margin, and the actual combustion amount is smaller than the integrated combustion amount. It remains and it is possible to continue operation of the equipment.
[0024]
After the display at the second stage is performed, in S6, the pH value detected by the pH meter 93 starts to be sent to the control unit, and the control unit manages this pH value. Then, while the operation of the device is further continued, in S7, it is determined whether or not the pH value is out of a safe range of 5.8 to 8.6 that conforms to the Sewerage Law. If the pH value is out of the safe range, it indicates that the neutralization capability has actually been lost in the neutralizer 85, and the operation of the device is stopped in S8. Specifically, the original gas solenoid valve 21 of the gas supply pipe 17 is closed.
[0025]
In this example, the detection of the pH is started after the second-stage display is performed, but the pH may be detected from the start of the operation of the device.
[0026]
In this way, the heat source unit can be operated until the neutralizing device loses its neutralizing ability if the device main body is in a normal state. In the case where the amount of the neutralizing agent is 15 years of the integrated combustion amount as in the current situation, the period until the neutralizing capability of the neutralizer is lost is much longer than 15 years. However, since the equipment has a design life (10 years), a considerable amount of neutralizer is wasted at present. Therefore, by performing the above-described control, the amount of the neutralizing agent can be made smaller than the current amount.
[0027]
【The invention's effect】
As is apparent from the above description, according to the present invention, the pH of the drain is detected by the pH detection unit, and the shutdown of the device is determined from the actual neutralization capacity of the neutralizer. The apparatus can be operated until the neutralization capacity of the neutralizer is lost, and the operation is stopped immediately when the neutralization capacity decreases. Therefore, the operable time of the device can be extended, and the amount of the neutralizing agent mounted on the heat source device can be reduced.
[Brief description of the drawings]
FIG. 1 is a flowchart showing processing when the operation of a heat source device according to an embodiment of the present invention is stopped.
FIG. 2 is a diagram schematically showing a configuration of a main body of a latent heat recovery type heat source device and a main piping system according to one embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat source unit 3 Combustion chamber 5 Primary heat exchanger 7 Secondary heat exchanger 9 Burner 11 Fan 13 Exhaust port 15 Rotation speed sensor 17 Gas supply pipe 19 Filter 21 Original gas solenoid valve 23 Gas proportional valve 25 Gas solenoid valve 27 Capability switching Gas solenoid valve 31 Ignition plug 33 Burner sensor 35 Frame rod 37 Ignition device 39 Overheat prevention device 51 Water supply pipe 53 Hot water supply pipe 55 Drain plug 57 Filter 59 Water volume sensor 61 Water thermistor 63 Drain plug 65 Can body thermistor 67 Water volume adjustment valve 69 Hot water thermistor 71 Drain plug 73 Bypass water amount adjusting valve 75 Bypass pipe 81 Receiving tray 83 Drain pipe 85 Neutralizer 87 Water level electrode 89 Drain plug 91 Drain pipe 93 pH meter

Claims (2)

A burner for burning fuel,
A heat exchanger that is heated by the burner and also recovers latent heat of steam in the combustion exhaust gas generated by the burner;
A drain drainage system for neutralizing and draining a drain generated in the heat exchanger,
A control unit for controlling each unit,
A heat source device comprising:
On the downstream side of the drain neutralizer arranged in the drain drainage system, a drain pH detection unit is attached,
A heat source unit, wherein a signal regarding the pH of the drain after neutralization is sent from the unit to the control unit, and when the value of the signal is out of a predetermined range, the combustion of the burner is stopped. Having an integrator for integrating the amount of fuel sent to the burner,
Predict the remaining amount of the neutralizing agent in the neutralizer based on the integrated value of the integrator,
When the estimated remaining amount of the neutralizing agent is less than a certain amount, a display to that effect is displayed by a character or an error code,
2. The heat source unit according to claim 1, wherein the burner stops burning when the pH detection unit signal is out of the range.

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