JP2006329457A - Hot water heating system and its circulated hot water temperature control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water heating system and a circulated hot water temperature control method, superior in durability of a heat source machine, energy saving property of the system, and silence without impairing amenity. <P>SOLUTION: A hot water temperature becomes lower in accompany with the stop of combustion. During the lowering, a prescribed time t1 has passed from the stop of the operation of a circulation pump or not is determined (Step S109). When the time is within t1, this state is kept as it is (NO in S109). When the prescribed time t1 has passed (YES in S109), the operation of the circulation pump 7 is restarted (step S110). Further, whether the temperature is lower than a set temperature Ts or not is determined (step S111). When the temperature is Ts or more, the state is kept as it is (NO in S111). When the temperature is lower than Ts (YES in S111), the combustion of a burner is restarted (step S112). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hot water heating system for supplying heating hot water to a terminal using a circulation pump and a circulating hot water temperature control method thereof.

  Conventionally, in a hot water heating system that supplies hot water with a circulation pump, burner combustion amount (maximum combustion, proportional combustion, minimum combustion, intermittent (ON-OFF) combustion) and circulation pump output (strong, weak) corresponding to the detected temperature of the hot water ) Is appropriately selected to reduce the number of times the combustion is turned on and off (for example, Patent Document 1). As a result, it is possible to extend the life of the equipment, save energy in the circulation pump, and reduce the noise.

However, since the heating load is generally small in the steady state, the room temperature rises even if the output of the circulation pump is weak and the operating condition is the minimum combustion amount. In this case, the combustion is stopped. In the above system, the circulation pump is continuously operated even in the combustion stopped state. Therefore, heat loss from the heat source unit heat exchanger and the piping during this period continuously occurs, which is a problem from the viewpoint of energy saving.
JP 2001-116267 A

  The present invention is intended to solve such problems, and is a hot water heating system excellent in durability of the heat source unit, energy saving of the system, and noise reduction without impairing comfort, and its circulating hot water temperature control. The technique regarding the method is provided.

The gist of the present invention is as follows. That is, the circulating hot water temperature control method of the hot water heating system according to the present invention is:
(1) A heat source that includes a combustion section that includes a burner and a heat exchanger, and that heats circulating hot water, a circulation pump, and a temperature sensor that detects the temperature of the circulating hot water, and a heat radiating terminal installed indoors In a hot water heating system comprising a hot water piping system connecting between a heat source device and a heat radiating terminal, during the burner intermittent combustion, the operation of the circulation pump is stopped in accordance with the combustion stop, and either the circulating hot water temperature or the combustion stop time is selected. The circulating hot water temperature control is performed by sequentially restarting the operation of the circulating pump and the burner combustion based on one or both of the predetermined conditions.

(2) The operation of the circulating pump is resumed prior to the restart of combustion after a lapse of a predetermined time from the stop of combustion.
(3) The predetermined time is determined according to a required hot water temperature from the terminal.
(4) The combustion is restarted when the temperature detected by the temperature sensor is equal to or lower than a predetermined temperature.
In this case, the circulation pump can be intermittently operated to measure the hot water temperature, and combustion can be resumed when the hot water temperature becomes a predetermined temperature or lower. Thereby, since the hot water temperature of a heating terminal part can be grasped | ascertained immediately inside an apparatus, energy-saving can be achieved without impairing comfort.
(5) It is characterized in that the time from the stoppage of the circulation pump to the resumption of operation is changed according to the rate of decrease in the circulating hot water temperature.
(6) In the hot water heating system according to (1) above, the hot water piping system further includes a shutoff valve, and when the burner combustion is stopped during intermittent combustion, the shutoff valve is closed instead of shutting down the circulation pump. And then, when the combustion is resumed, the closing valve is opened.

A hot water heating system according to the present invention includes:
(7) A heat source that includes a combustion section that includes a burner and a heat exchanger, and that heats circulating hot water, a circulation pump, and a temperature sensor that detects the temperature of the circulating hot water, and a heat radiating terminal installed indoors In a hot water heating system comprising a hot water piping system connecting between a heat source device and a heat radiating terminal, means for stopping the operation of the circulation pump in accordance with the combustion stop, and the circulating hot water temperature or the combustion stop time at the time of intermittent combustion of the burner And a means for restarting the operation of the circulating pump and burner combustion based on one or both of the predetermined conditions.

  (8) The heat source device further includes a latent heat recovery heat exchanger.

  According to the present invention, since the circulation pump operation is stopped while the combustion is stopped during intermittent combustion, it is possible to reduce a heat dissipation loss from a portion that is in contact with the outside air, such as a heat exchanger or a pipe. Thereby, energy saving can be achieved.

On the other hand, since heat radiation from the indoor heating terminal is continuously performed even when the circulation pump operation is stopped, there is an effect that indoor comfort is not impaired.
In addition, in the invention in which the operation of the circulation pump is not stopped and the shutoff valve is opened and closed instead, the same effect can be obtained and the durability of the circulation pump can be improved.
In a system using a heat source unit equipped with a latent heat recovery heat exchanger, the heat efficiency of the latent heat recovery unit depends strongly on the temperature of the heat source unit, that is, the return temperature to the heat source unit. There is an effect that the return temperature at the time of restart can be expected to decrease.

  Hereinafter, an embodiment of a hot water heating system according to the present invention will be described in more detail with reference to FIGS. In addition, in order to avoid duplication, in each figure, the same structure is shown using the same code | symbol. Needless to say, the scope of the present invention is described in the claims and is not limited to the following embodiments.

(First embodiment)
This embodiment is an embodiment mainly corresponding to claim 2. FIG. 1 shows an overall configuration of a hot water heating system 1 according to a first embodiment of the present invention. In the figure, the hot water heating system 1 includes a heat source machine 2, a heating terminal 3, and a heating forward pipe H1 and a heating return pipe H2 connecting the heat source machine 2 and the heating terminal 3. The heat source unit 2 includes an open-type cistern 5, a circulation pump 7, a heat exchanger 8 that supplies heat obtained from the combustion gas to the heat medium (water), pipes H3 to H5 that connect these devices, A control unit 15 that controls operation control is provided. The cistern 5 is a buffer tank for expansion of hot water in the pipe accompanying the heating operation, and is configured to be drained to the outside through an overflow pipe (not shown) when the hot water rises above a predetermined water level. In the pipe H5 path, a thermistor 17 for detecting the outward hot water temperature and a thermal valve V1 as an on-off valve are provided.

  Hot water circulation during the heating operation of the hot water heating system 1 is performed as follows. As the operation starts, the circulation pump 7 is driven and the thermal valve V1 is opened. As a result, the water in the cistern 5 is sent to the heat exchanger 8 via the pipe H4, heated here to become warm water, and sent to the heating terminal 3 via the pipe H5 and the outgoing pipe H1. The hot water radiates heat indoors at the heating terminal 3 and is returned to the systern 5 via the return side pipe H2 and the pipe H3.

  The combustion system of the heat source unit 2 includes a gas pipe 10, a gas proportional valve V2, a burner 9, a combustion chamber (not shown), and a heat exchanger 8 as main components. The city gas supplied through the gas pipe 10 burns in the burner 9 and becomes combustion gas, and heats the circulating hot water in the heat exchanger 8. The combustion exhaust gas that has exited the heat exchanger 8 is discharged to the outside via an exhaust section (not shown). The combustion amount of the burner 9 is controlled by adjusting the opening of the gas proportional valve V2.

  The control system of the hot water heating system 1 includes a control unit 15 on the heat source device 2 side and a floor warming controller 13 installed on the indoor side. That is, the operation request from the floor warming controller 13 is transmitted to the control unit 15 in the heat source unit 2 through the control line 18, and the control unit 15 starts and stops the combustion of the burner 9 and adjusts the opening of the gas proportional valve V <b> 2. This is done by instructing the driving and stopping of the circulation pump 7, opening and closing of the thermal valve V1, etc., and responding to the request.

  The hot water heating system 1 is configured as described above. Next, a circulating hot water temperature control flow in this system will be described with reference to FIGS. 2 and 3. When there is a heating operation request (required hot water temperature Ts) from the floor warming controller 13, the operation of the circulation pump 7 is started (step S101), and then the thermal valve V1 is opened. Next, it is determined whether or not the hot water temperature exceeds T1 (step S102). If the detected value of the hot water temperature of the thermistor 17 at this time is T0 (NO in step S102, at this time position P0 in FIG. 3), the burner 9 is maximally burned when the proportional valve V1 is fully opened (step S103). In this state, combustion is continued until the hot water temperature exceeds T1.

When the hot water temperature exceeds T1 (YES in step S102), the opening degree of the gas proportional valve V2 is adjusted so as to maintain the set hot water temperature Ts by proportional combustion. In this case, if the heating load and the combustion amount are balanced, the required hot water temperature Ts is maintained at a certain valve opening (position P1 in FIG. 3).

  When the heating load is small and the hot water temperature is higher than the required temperature, the opening degree of the proportional valve V2 is further reduced. During this time, it is determined whether the hot water temperature has exceeded T2 at a predetermined interval (step S105). When T2 or less, the process returns to the determination step of S103 described above (NO in S105). When T2 is exceeded (YES in S105), burner 9 is in minimum combustion (step S106). It is determined whether the hot water temperature has exceeded T3 under the minimum combustion condition (step S107). When T3 or less, the process returns to the determination step of S105 described above (NO in S107). When T3 is exceeded (YES in S107), combustion of burner 9 is stopped, and then operation of circulation pump 7 is stopped (step S108). As the combustion stops, the hot water temperature decreases. During this time, it is determined whether a predetermined time (t1) has elapsed since the circulation pump was stopped (step S109). This state is continued within t1 (NO in S109). When predetermined time t1 has elapsed (YES in S109), operation of circulating pump 7 is resumed (step S110). Further, it is determined whether or not the temperature is lower than the set temperature Ts (step S111). If it is equal to or greater than Ts, this state is continued (NO in S111). When it falls below Ts (YES in S111), burner combustion is resumed (step S112).

  The above steps are continuously performed during operation. When there is a heating operation end request during operation, the operation of the entire system is stopped at that time (the same applies to the following embodiments).

(Second embodiment)
Next, another embodiment of the present invention will be described with reference to FIG. This embodiment is an embodiment mainly corresponding to claim 2. Since the configuration of the present embodiment is the same as that of the hot water heating system 1 in the first embodiment, the description thereof is omitted. The present embodiment is different from the above-described embodiment in that, in the above-mentioned embodiment, after the circulation pump operation is restarted (step S110), the combustion restart is determined based on the hot water temperature T. Is based on the required hot water temperature. That is, the time from the stop of combustion to the restart of combustion is made different from t2, t3, and t4, depending on the required hot water temperature of the terminal being 40 ° C, 60 ° C, or 80 ° C.

  Referring to FIG. 4, when there is a heating operation request (required hot water temperature Ts) from floor warming controller 13, operation of circulating pump 7 is started (step S201), and then thermal valve V1 is opened. The Next, it is determined whether or not the hot water temperature exceeds T1 (step S202). If the detected value of the hot water temperature of the thermistor 17 at this time is T0 (NO in step S202, at this time position P0 in FIG. 3), the burner 9 is fully burned when the proportional valve V1 is fully opened (step S203). In this state, combustion is continued until the hot water temperature exceeds T1.

When the warm water temperature exceeds T1 (YES in step S102), the opening of the gas proportional valve V2 is adjusted so as to maintain the set warm water temperature Ts by proportional combustion (step S204). In this case, if the heating load and the combustion amount are balanced, the required hot water temperature Ts is maintained at a certain valve opening (position P1 in FIG. 3).

  When the heating load is small and the hot water temperature is higher than the required temperature, the opening degree of the proportional valve V2 is further reduced. During this time, it is determined whether the hot water temperature has exceeded T2 at a predetermined interval (step S205). When T2 or less, the process returns to the determination step of S202 described above (NO in S205). When T2 is exceeded (YES in S205), burner 9 is in minimum combustion (step S206). Next, it is determined whether the hot water temperature has exceeded T3 under the combustion conditions (step S207). When T3 or less, the process returns to the determination step of S205 described above (NO in S207). When T3 is exceeded (YES in S207), combustion of burner 9 is stopped, and then operation of circulating pump 7 is stopped (step S208).

  Next, the terminal required hot water temperature is determined (step S209). When the required temperature is 40 ° C., it is determined whether the combustion stop time has exceeded t2 (step S210). When t2 or less (NO in S210), the combustion stop is continued. When t2 is exceeded (YES in S210), the operation of the circulation pump is resumed (step S213), and then combustion is resumed (step S214).

  When the required temperature is 60 ° C., it is determined whether the combustion stop time has exceeded t3 (step S211). When t3 or less (NO in S211), the combustion stop is continued. When t3 is exceeded (YES in S211), the operation of the circulation pump is resumed (step S213), and then combustion is resumed (step S214).

  When the required temperature is 80 ° C., it is determined whether the combustion stop time has exceeded t4 (step S212). When t4 or less (NO in S212), the combustion stop is continued. When t4 is exceeded (YES in S212), the operation of the circulation pump is resumed (step S213), and then combustion is resumed (step S214).

In the above description, the required hot water temperature is an example, and an arbitrary temperature condition can be selected.
(Third embodiment)
Furthermore, another embodiment of the present invention will be described with reference to FIG. This embodiment corresponds to the sixth aspect. Since the configuration of the present embodiment is the same as that of the hot water heating system 1 in the first embodiment, the description thereof is omitted. The present embodiment is different from the above-described embodiment in that, in the above-described embodiment, when the hot water temperature exceeds the upper limit temperature, the operation of the circulation pump 7 is stopped together with the combustion stop. Instead of this, the thermal valve V1 is closed. In this case, the hot water is circulated in the machine via a bypass pipe (not shown) in the heat source machine 2.

  In FIG. 5, steps S301 to S308 are the same as those in the above-described embodiment, and a description thereof will be omitted. Next, when the hot water temperature exceeds T3 (YES in S308), the combustion is stopped and then the thermal valve V1 is closed (step S309). Along with this, the hot water temperature decreases. It is determined whether a predetermined time t1 has elapsed since the circulation pump was stopped (step S310). When it is within t1, this state is continued (NO in S310). When predetermined time t1 has elapsed (YES in S310), thermal valve V1 is opened again (step S311). Subsequent steps are the same as those in the first embodiment, and a description thereof will be omitted.

(Fourth embodiment)
Furthermore, another embodiment of the present invention will be described with reference to FIG. This embodiment corresponds to claim 5. The configuration of the present embodiment is also the same as that of the hot water heating system 1 in the first embodiment. The difference between the present embodiment and the first embodiment is that in the first embodiment, the operation of the circulation pump 7 is resumed after a predetermined time (t1) has elapsed since the circulation pump operation was stopped. The time (ts) until the circulation pump operation is restarted is set based on the hot water temperature decrease rate.

  In FIG. 6, steps S401 to S408 are the same as those in the first embodiment, and a description thereof will be omitted. Next, a hot water temperature decrease rate (ΔT) is calculated (step S409). Further, a predetermined circulation pump stop time (ts) is set based on the hot water temperature decrease rate (step S410). Then, it is determined whether the set time ts has elapsed since the circulation pump operation was stopped (step S411). When it is within ts, this state is continued (NO in S411). When the set time ts has elapsed (YES in S411), the operation of the circulation pump 7 is resumed (step S412). Subsequent steps are the same as those in the first embodiment, and a description thereof will be omitted.

(Fifth embodiment)
Furthermore, another embodiment of the present invention will be described with reference to FIG. This embodiment corresponds to the eighth aspect. The present embodiment is different from the first embodiment in that the hot water heating system 1 according to the first embodiment has one heat exchanger, whereas the hot water heating system 20 according to the present embodiment has heat. It has two exchangers. That is, a latent heat recovery heat exchanger 21 is provided in the middle of the hot water pipe connecting the circulation pump 7 and the heat exchanger 8. As a result, the hot water is guided to the heat exchanger 8 after passing through the open systern 5 → the circulation pump 7 → the heat exchanger 21. On the other hand, regarding the configuration of exhaust heat recovery, the heat exchanger 21 is provided on the downstream side of the heat exchanger 8 in the exhaust gas path. The heat exchanger 21 is provided with a condensed water neutralization device (not shown). With such a configuration, the combustion gas generated in the burner 9 is heated in the heat exchanger 8 and then the latent heat is recovered in the heat exchanger 21 and finally passes through the exhaust section (not shown). And discharged to the outside. For this reason, compared with the conventional system, the return temperature to the heat exchanger 21 becomes lower and the latent heat recovery amount increases. In addition, the condensed water collect | recovered with the heat exchanger 21 is drained outside after passing a neutralization apparatus.

  The present invention is widely applicable to hot water heating systems regardless of the heat source.

It is a figure which shows the hot water heating system. It is a figure which shows the combustion control flow in 1st embodiment. It is a figure which shows the relationship between burner combustion control and warm water temperature in 1st embodiment. It is a figure which shows the combustion control flow in 2nd embodiment. It is a figure which shows the combustion control flow in 3rd embodiment. It is a figure which shows the combustion control flow in 4th embodiment. It is a figure which shows the hot water heating system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot water heating system 2 Heat source machine 3 Heating terminal 5 Open type cistern 4 High temperature terminal 7 Circulating pump 8 Heat exchanger 9 Burner 10 Gas piping 13 Floor warming controller 15 Control part 17 Thermistor 18 Control line H1-H5 Heating piping TH0 Condensation avoidance Temperature TL Low temperature V1 Thermal valve V2 Gas proportional valve

Claims (9)

A heat source including a combustion section that includes a burner and a heat exchanger and heats circulating hot water, a circulation pump, and a temperature sensor that detects the temperature of the circulating hot water, a heat radiating terminal installed indoors, and a heat source And a hot water heating system comprising a hot water piping system connecting between the heat radiating terminals,
During burner intermittent combustion, the operation of the circulation pump is stopped in accordance with the combustion stop, and the operation of the circulation pump and the burner combustion are sequentially resumed based on a predetermined condition of one or both of the circulating hot water temperature and the combustion stop time. A circulating hot water temperature control method for a hot water heating system, wherein the circulating hot water temperature control is performed. The method for controlling the circulating hot water temperature of a hot water heating system according to claim 1, wherein the operation of the circulating pump is restarted prior to resuming combustion after a predetermined time has elapsed since the stop of combustion. The circulating hot water temperature control method for a hot water heating system according to claim 2, wherein the predetermined time is determined according to a required hot water temperature from the terminal. 4. The method for controlling the circulating hot water temperature of a hot water heating system according to claim 1, wherein combustion is resumed when a temperature detected by the temperature sensor is equal to or lower than a predetermined temperature. The method for controlling the circulating hot water temperature of the hot water heating system according to any one of claims 1 to 4, wherein the time from the stoppage of the circulation pump to the resumption of operation is changed according to the rate of decrease in the circulating hot water temperature. The hot water heating system according to claim 1, further comprising a shutoff valve in the hot water piping system, and when the burner combustion is stopped during intermittent combustion, the shutoff valve is closed instead of shutting down the circulation pump. A method for controlling the circulating hot water temperature of a hot water heating system, wherein the closing valve is opened when combustion is resumed. A heat source including a combustion section that includes a burner and a heat exchanger and heats circulating hot water, a circulation pump, and a temperature sensor that detects the temperature of the circulating hot water, a heat radiating terminal installed indoors, and a heat source And a hot water heating system comprising a hot water piping system connecting between the heat radiating terminals,
Means for stopping the operation of the circulation pump in accordance with the stop of combustion at the time of burner intermittent combustion;
Means for resuming operation of the circulation pump and burner combustion based on a predetermined condition of either or both of the circulating hot water temperature and the combustion stop time;
A hot water heating system characterized by comprising: The hot water heating system according to claim 7, wherein the heat source device further includes a latent heat recovery heat exchanger. 5. The circulating hot water temperature control method for a hot water heating system according to claim 4, wherein the circulating pump is operated intermittently to measure the hot water temperature.

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