JP5326650B2 - Heating control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating control device promptly and accurately detecting a circulating flow rate without using a direct detection means such as a flow rate sensor. <P>SOLUTION: A circulating pump is turned on to confirm and stir remaining water in a bathtub and it is confirmed that a water jet SW is turned on (S1, S2). A combustion burner is turned on for heating to a predetermined temperature, and the combustion burner is extinguished while maintaining the circulation state (S3-S5). Change in going temperature detected by a going temperature sensor downstream of a heat exchange is monitored, and a timer means is turned on to measure a lowering time value until the going temperature is lowered only by a set temperature difference &Delta;T (S6, S7). Based on a relationship table determining beforehand a relationship between the lowering time value and a value of the circulating flow rate, a value of the corresponding circulating flow rate is determined. The amount of remaining hot water is calculated by using the obtained value of the circulating flow rate and the shortage amount of hot water is filled (S9, S10). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a heating control device for a circulating fluid heated by a heat source in a heat exchanger, and in particular, without using a detection means such as a flow sensor to directly detect the flow rate, The present invention relates to a control technique that can be detected by a control process.

  Conventionally, as a heating control device of this type, for a hot water supply device provided with a recirculation circuit, the flow rate in the recirculation circulation channel can be detected without providing a flow rate sensor in the recirculation circulation channel. Have been proposed (see, for example, Patent Document 1). That is, in a one-can two-water channel hot water supply device in which a hot water supply heat exchanger and a reheating heat exchanger are heated by a common combustion burner, when the reheating is attempted, the water in the hot water supply circuit is simultaneously heated. It will be done. For this reason, when the reheating operation is performed independently, combustion of the combustion burner is stopped when the temperature on the hot water supply heat exchanger side exceeds a predetermined off temperature, and the combustion burner is combusted again when the temperature is lowered to the on temperature. The intermittent combustion operation is performed. In such a case, in order to detect the circulation flow rate in the recirculation circuit, the stop time from the combustion stop of the combustion burner to the start of the next combustion and the temperature of the circulation flow are detected, and these are detected. The combination of the stop time and the temperature is compared with the relation data of the stop time, the temperature of the circulation flow and the circulation flow rate created in advance, and the corresponding circulation flow rate is derived from the relation data.

  In addition, as a similar heating control device, a one-can / two-water-type hot water supply device in which the combustion burner is operated intermittently in the same manner as described above when the reheating operation is performed alone. There has been proposed one that detects a circulating flow rate in a circulation circuit without using a flow rate sensor. In other words, relationship data between the burner off time from the stop of combustion to the restart of combustion and the circulation flow rate is created in advance, and the temperature detection from the off temperature to the on temperature of the circulation flow and the combustion on / off information of the combustion burner are obtained. It detects and circulates the corresponding circulation flow rate by collating with the above relational data.

JP 11-159862 A JP 11-173664 A

  However, the circulating flow rate detection method in the heating control device has a disadvantage that the detected circulating flow rate is extremely inaccurate. That is, in the case of combustion stop, the fuel supply is shut off and extinguishes at the same time, so the timing of combustion stop can be almost accurately grasped as the output timing of the control signal of combustion stop, but the timing of combustion start depends on various factors In many cases, therefore, it does not coincide with the output timing of the control signal for starting combustion, and in reality, it is difficult to grasp the timing for starting combustion. In other words, even if the fuel supply is started and the ignition operation is performed, the ignition operation is not performed immediately, but several ignition operations are performed due to various factors such as blowing of wind and clogging of the flow path of the combustion exhaust gas. It may be ignited by repeating. For this reason, it is not practical to accurately grasp the start timing of combustion only by the output timing of a control signal for fuel supply operation, a control signal for ignition operation, etc., and combustion is performed at such timing. In the case of the circulating flow rate detection method used as the start timing, the value of the detected circulating flow rate is hardly accurate.

  By the way, in the recirculation circuit, it is impossible to install a normal water turbine type flow sensor in the recirculation circuit because it is trying to grasp the circulation flow rate by the complicated control as described above. This is because the rated discharge flow rate of the circulation pump does not represent the actual circulation flow rate. That is, the fluid circulated in the recirculation circuit is bathtub hot water, and it is expected that hair will be mixed in the bathtub hot water. It is not possible to detect the circulating flow rate directly. Even if the rated discharge flow rate of the circulation pump installed in the recirculation circuit is known, the recirculation flow rate in the recirculation circuit connecting the bathtub with the open water surface and the heat exchanger is It does not match the discharge flow rate, and the circulation flow rate cannot be grasped by the discharge flow rate of the circulation pump.

  On the other hand, if the object to be controlled is of a single can / two water channel type, especially when there is remaining hot water in the bathtub, it takes time to grasp the amount of remaining hot water. There is a problem that the time becomes long, and in order to solve this problem, the rapid and accurate detection (grasping) of the circulating flow rate of the recirculation circuit is a particularly important issue.

  That is, as a process for determining the amount of remaining hot water (processing for calculating the amount of remaining hot water), calorie calculation based on the comparison between the amount of heat applied by reheating and the temperature rise of the bath water, Calorie calculation based on the contrast with the temperature rise width, or calorie calculation based on the contrast between the amount of heat (cold heat) applied by pouring water from the hot water supply side and the temperature drop width of the bath water, can be considered. In this case, since the former two are inappropriate, it is necessary to apply calorific value calculation by water injection. In other words, in the case of reheating, since the heat exchanger for both reheating and hot water supply is heated by a common combustion burner, the combustion burner is operated for combustion for reheating operation. However, not all of the amount of heat generated by the combustion burner is applied to the circulating flow in the recirculation circuit, but is also applied to the hot water supply side. For this reason, the amount of combustion heat given to the reheating side cannot be specified, and the combustion operation itself or the amount of combustion is changed to prevent overheating on the hot water supply side as in the above-mentioned conventional one, and the combustion burner Therefore, it is impossible to accurately grasp the amount of heat applied. In addition, in the case of pouring, when pouring the hot water from the hot water supply side and dropping it into the bathtub by both transport using both the return circuit and the forward flow path, when passing through the heat exchanger in one flow path As a result of unintentional heating being applied to the tub, the total amount of heat supplied to the bathtub cannot be grasped.

  In the case of water injection, first, the circulating pump is operated to agitate the bathtub hot water, a predetermined amount of water is poured from the hot water supply side to the bathtub, and the temperature is lowered after the circulation pump is operated to agitate the bathtub hot water. Next, the remaining hot water amount is calculated from the temperature difference and the known water injection temperature and water injection amount. Such a process requires a considerable time (for example, about 10 minutes).

  The present invention has been made in view of such circumstances, and an object of the present invention is to detect the circulation flow rate in the circulation circuit without using a direct detection means such as a flow rate sensor. And it is providing the heating control apparatus which can perform the detection of the circulating flow rate rapidly and correctly.

In order to achieve the above object, the present invention provides a circulation path through which a fluid is circulated, a heat exchanger interposed in the circulation path, and a heating source that heats and heats the fluid flowing through the heat exchanger. The following specific matters are provided for a heating control device applied to a heating device including: That is, a forward temperature detecting means for detecting the temperature of the forward fluid in the circulation path downstream of the heat exchanger in the circulation direction, and a circulating flow rate of the fluid circulated through the circulation path is detected by control processing. A circulating flow rate detection processing unit. The circulating flow rate detection processing unit includes timer means for measuring an elapsed time value and a table storage unit for storing a predetermined relation table. The relationship table shows that the flow rate of the fluid in the circulation path and the drop from when the heating operation of the heating source stops until the temperature of the forward fluid detected by the forward temperature detection means drops by the set temperature difference. It is assumed that the relationship with the time value is set in advance. Then, as the circulation flow rate detection process, the heating operation of the heating source is stopped while maintaining the inside of the circulation path in a fluid circulation state, while the temperature change of the forward fluid detected by the forward temperature detection means is monitored. The timer means measures the descent time value required for the temperature of the forward fluid to drop by the set temperature difference from the time when the heating operation is stopped, and corresponds from the relation table based on the measured descent time value. it configured to detect indexing the value of the circulating flow. Furthermore, as the circulating flow rate detection processing unit, a plurality of types of relationship tables set in advance in the table storage unit as being applied to a plurality of types of heat capacities that are different from each other in heat capacity of the heat exchanger at the time when the heating operation is stopped Is stored, and the relation table to be applied is changed and set depending on the output of the detected value or the set value representing the heat capacity (claim 1).

In the case of this invention, it is possible to accurately reflect the actual operating status of the heating device and the actual temperature change status of the circulating fluid as the descent time value measured by the timer means. Since the corresponding circulation flow rate value is calculated from the relation table based on the value, an accurate value can be obtained as the circulation flow rate value detected not by direct detection but by control processing. That is, the timing of extinguishing the heating source (for example, the combustion burner) can be accurately grasped compared with that of ignition (heating start) and the measurement by the timer means can be started because the control timing and the actual extinguishing match each other. In addition, since the time point at which the set temperature difference is generated can be accurately detected by the forward temperature detecting means, the fall time value measured by the timer means can accurately reflect the actual situation. Moreover, the measurement of the descent time value until the temperature of the circulating fluid drops by the set temperature difference after stopping the heating by the heating source is the main time required for the detection process, so the value of the circulation flow rate can be obtained quickly. . As described above, the circulation flow rate in the circulation circuit can be detected without using a direct detection means such as a flow rate sensor, and the circulation flow rate can be detected quickly and accurately. Note that the relationship table, in addition to the relational curve or table of values, Ru der but also the relational expression indicating the approximate expression such as the relation curve (equation). The detection value or setting value representing the heat capacity is, for example, the detection value of the return side temperature of the circulating flow when the circulating flow is returned to the heat exchanger, after being heated by the heat exchanger The detected value of the forward side temperature emitted from the heat exchanger or the set temperature of the fluid that is the heating target when stopping the heating operation may be used. Alternatively, a detection value of the combustion amount may be used as a detection value representing the heat capacity. Then, by changing and setting the relation table to be applied depending on the heat capacity of the heat exchanger in this way, the accuracy of the circulating flow rate value obtained by the detection process can be further increased.

  The heating device according to the present invention can be a bath with a recirculation circuit in which hot and cold water is circulated between a heat exchanger and a bathtub as a circulation path (Claim 2). In this case, it becomes possible to accurately and quickly grasp the circulation flow rate for the reheating in the reheating circulation path in which direct flow rate detection means such as a flow rate sensor cannot be installed due to contamination of hair or the like. .

  Further, the heating device includes a hot water supply circuit in addition to the reheating circulation circuit, and a can 2 configured to heat the reheating heat exchanger and the hot water heat exchanger by a common heating source. It can be constituted by a water bath type water bath with a water heater (Claim 3). In this case, especially when there is remaining hot water in the bathtub, it takes time to grasp the amount of remaining hot water, and as a result, the time until the completion of automatic hot water filling becomes longer. This makes it possible to solve the problems peculiar to the hot water bath with water heater. And when applying to such a 1 can 2 water channel type water heater with a hot water heater, there is a remaining hot water in the bathtub in the hot water filling control for the bathtub with the detection process of the circulating flow value by the circulating flow rate detection processing section. It can comprise so that it may perform in the state which detected doing (Claim 4). Not only is it possible to detect the value of the circulating flow rate using the remaining hot water, but the value of the circulating flow rate can be obtained at this stage, so that subsequent hot water filling control can be simplified. That is, when executing the hot water filling control for the bathtub, the hot water filling control unit for calculating the remaining hot water amount in the bathtub is further provided. As the hot water filling control unit, the value of the circulating flow rate detected by the circulating flow rate detection processing unit is obtained. It can be set as the structure which calculates the amount of remaining hot water using (Claim 5). Before the calculation of the remaining hot water amount, the value of the circulating flow rate is grasped by the detection processing by the circulating flow rate detection processing unit, so that the calculation of the remaining hot water amount becomes easy using the value of the circulating flow rate. The time required to complete the control can be significantly shortened compared to the case of a conventional can with a single can and two water channels.

  On the other hand, in the above heating control device, it is further provided with an outside air temperature detecting means for detecting the outside air temperature, and the circulation flow rate detection processing section as the circulation time value measured by the timer means or the circulation calculated from the relation table. The flow rate value can be corrected depending on whether the outside air temperature detected by the outside air temperature detecting means is high or low (Claim 6). By doing in this way, the influence of outside temperature is also taken into consideration and it becomes possible to detect the circulation flow rate more accurately.

  Alternatively, an outside air temperature detecting means for detecting the outside air temperature is provided, and a plurality of types of relation tables set in advance as those to be applied to a plurality of different outside air temperatures are stored in the table storage unit as the circulation flow rate detection processing unit. The relationship table to be applied can be changed and set depending on whether the outside air temperature detected by the outside air temperature detecting means is high or low (claim 7). By doing so, it becomes possible to detect the circulating flow rate more accurately by taking into account the influence of the outside air temperature by means different from the above correction processing.

As described above, according to the heating control device of any one of claims 1 to 7 , the descent time value accurately reflects the actual operating status of the heating device and the actual temperature change status of the circulating fluid. By measuring and calculating from the relationship table using this descent time value, the circulation flow rate in the circulation circuit can be detected without using a direct detection means such as a flow sensor. ing to be able to perform the detection quickly and accurately. In addition, since any heat capacity of the heat exchanger is taken into account, the accuracy of the circulating flow rate value obtained by the detection process can be further increased.

  In particular, according to claim 2, in a recirculation circuit where direct flow rate detection means such as a flow sensor cannot be installed due to contamination of hair or the like, the recirculation flow rate for reheating is accurately and quickly grasped. Will be able to.

  According to claim 3, especially when there is remaining hot water in the bathtub, it takes time to grasp the amount of remaining hot water, and as a result, the time until completion of automatic hot water filling becomes longer. This makes it possible to solve problems peculiar to a can with a two-channel water heater. According to the fourth aspect of the present invention, in the one-bottle / two-channel hot water bath equipped with a hot water heater, the circulation flow rate value detection process is executed in a state where it is detected that there is remaining hot water in the bathtub. Thus, not only can the processing of detecting the value of the circulating flow rate using the remaining hot water be performed, but also the value of the circulating flow rate can be obtained at this stage, so that subsequent hot water filling control can be simplified. . In addition, according to claim 5, since the value of the circulating flow rate is grasped by the detection process by the circulating flow rate detection processing unit before the calculation of the remaining hot water amount, the remaining hot water amount is calculated using the value of the circulating flow rate. As a result, the time required to complete the hot water filling control can be greatly shortened as compared with the case of the conventional one-can / two-water-channel hot water heater.

  Further, according to claim 6 or claim 7, it becomes possible to detect the circulation flow rate more accurately in consideration of the influence of the outside air temperature.

It is a mimetic diagram showing a bathtub with a 1 can 2 water channel type hot water heater to which an embodiment of the present invention is applied. It is a block diagram of the control composition concerning hot water filling control and circulation flow rate detection processing of a heating control device. It is a flowchart which mainly shows the procedure of a circulating flow rate detection process. FIG. 6 is a relationship diagram of temperature and time showing the change characteristic of the forward temperature after the combustion of the combustion burner is stopped when the circulating flow rate is large and when the circulation flow rate is small. It is a figure which shows the experimental data which measured the relationship between the temperature change immediately after the combustion stop of the combustion burner in various circulation flow in Example 1, and time. It is the figure showing the relationship between the temperature difference from combustion stop time, and time using the experimental data of FIG. It is the figure showing the relationship between a circulation flow rate value and the fall time value in which a predetermined temperature difference produces using the experimental data of FIG. It is a figure showing the relationship between the circulating flow value in Example 2, and the descent time value in which a predetermined temperature difference arises.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a can with two water channels and a water heater with a water heater as a heating device to which a heating control device according to an embodiment of the present invention is applied. This bath tub with a water heater is configured as a composite heat source machine type having both a hot water supply function, a bath reheating function, and a hot water filling function. In practicing the present invention, the present invention can be applied as long as it has at least a reheating function for a bath and a recirculation circuit is installed, and other configurations are not essential.

  In the figure, reference numeral 2 is a hot water supply circuit for realizing a hot water supply function, 3 is a reheating circulation circuit for realizing a bath reheating function, and 4 is a pouring circuit for realizing a bath filling function. There is a controller 5 for controlling the operation of each circuit. The hot water heater with water heater of the present embodiment includes a hot water supply heat exchanger 21 and a reheating heat exchanger 31 disposed in the same heat exchange can body, and is heated by the combustion heat of the common combustion burner 6. It is configured in a single can / two-channel system so that exchange heating is performed.

  The hot water supply circuit 2 heat-exchanges and heats the water introduced into the hot water supply heat exchanger 21 from the water inlet 22 connected to the water pipe by the combustion heat of the combustion burner 6, and the heated hot water is discharged into the hot water outlet 23. The hot water is supplied to a predetermined hot water supply location such as a hot water tap K such as a kitchen or a bathroom or the pouring circuit 4. A bypass passage 24 that bypasses the heat exchanger 21 is provided between the water inlet passage 22 and the hot water outlet passage 23, and water for the hot water from the hot water outlet passage 23 is adjusted by opening adjustment by position control of the bypass control valve 24a. The mixing ratio is changed and adjusted so that the temperature of the hot water tap K can be adjusted.

  A water flow rate sensor 25 and a water temperature sensor 26 are disposed in the water inlet 22, while the temperature of the hot water immediately after the hot water is discharged near the outlet of the heat exchanger 21 in the hot water path 23. A can body temperature sensor 27, a hot water supply flow rate control valve 28, and a hot water temperature sensor 29 for detecting the temperature of hot water supplied to the hot water tap K or a pouring passage 41 described later are disposed.

  The reheating circulation circuit 3 includes a reheating heat exchanger 31 through which the hot water in the bathtub B flows, a recirculation circulation path 32, and a circulation pump 33. The recirculation circuit 32 includes the return path 32a for returning the hot water in the bathtub B to the reheating heat exchanger 31 by the operation of the recirculation pump 33, and the reheating heat exchanger 31 and the common combustion burner. And an outward passage 32b for supplying hot water heated and reheated by the combustion heat of 6 to the bathtub B. The return path 32a detects the return temperature of the circulating hot water, the circulating pump 33, the water flow switch 34 that outputs a circulation determination ON command when the circulating flow passes, and the circulation determination ON command in order from the upstream side in the circulation direction. Thus, a return temperature sensor 35 for detecting the temperature of the hot water in the bathtub B (tub temperature) is provided. Further, in the outgoing path 32b on the downstream side in the circulation direction of the reheating heat exchanger 31, the recirculation temperature of the circulating hot water sent to the bathtub B after being subjected to heat exchange heating (refreshing heating) by the reheating heat exchanger 31 is detected. A forward temperature sensor 36 is disposed.

  Note that the combustion burner 6 performs a combustion operation in response to the supply of fuel gas from the fuel supply system 63 provided with the original gas valve 61 and the gas proportional valve 62 and the supply of combustion air from the blower fan 64. In the illustrated example, the combustion capacity can be switched in a plurality of stages by opening / closing switching control of the five capacity switching valves 65, 65,. A combustion system 66 is constituted by these components.

  The pouring circuit 4 switches between the hot water supply path 41 where the upstream end branches from the hot water supply path 23 of the hot water supply circuit 2 and the downstream end is joined to the recirculation circuit 32 and the execution and shut-off of the pouring by opening / closing switching. An electromagnetic pouring valve 42 and a pouring flow rate sensor 43 for detecting the pouring flow rate are provided. The pouring valve 42 is controlled to be opened and closed by the controller 5, and the hot water in the tapping path 23 is poured into the bathtub B through the pouring path 41 and the recirculation circulation path 32 (return path 32 a) as a result of pouring. The hot water filling is performed.

  The above-mentioned hot water heater equipped with a water heater is equipped with an MPU, a memory, and the like, and a controller 5 in which various control programs are stored allows various operation controls such as a hot water supply operation, a hot water filling operation by pouring and pouring water, and a reheating operation. In addition to being performed based on the output from the remote controller 51 and the outputs from the various sensors described above, the circulation flow rate of the recirculation circuit 3 can be detected without using a direct detection means such as a flow rate sensor as will be described later. This is done by the process. That is, the controller 5 includes a hot water supply control unit that performs a hot water supply operation on the hot water tap K by the hot water supply circuit 2 and a reheating control unit that performs a reheating operation that raises the hot water in the bathtub B to a predetermined temperature by the recirculation circuit 3. And a hot water filling control unit 52 (see FIG. 2) as a control means for performing hot water filling operation by pouring / watering into the bathtub B through the hot water pouring channel 41, and a circulating flow rate detection processing unit 53.

  The hot water supply control by the hot water supply control unit will be briefly described as follows. That is, when the hot water tap K is opened, water enters the water inlet 22 from the water pipe, and when the incoming water flow rate sensor 25 detects an incoming water flow rate of a minimum operating flow rate (MOQ; for example, 3 liters / minute) or more, the combustion system 6 The combustion operation control (for example, FF control) is started. Next, the combustion operation amount is controlled (for example, FB control) so that the hot water temperature set by the user is set in the remote controller 51 based on the detected values of the incoming water temperature from the incoming water temperature sensor 26 and the hot water temperature from the hot water temperature sensor 29. Is done. When the hot water tap K is closed by the user, the incoming water flow rate from the incoming water channel 22 becomes less than the minimum operating flow rate, and eventually zero, so the combustion operation is stopped and the hot water supply operation control is terminated.

  The chasing control by the chasing control unit is performed as follows. That is, when the user turns on the reheating switch of the remote controller 51, or when the user turns on the automatic bath switch in the previous stage and the filling of the water up to the predetermined water level in the bathtub B is finished by the filling of the hot water, the reheating is finished. A command is output, and the circulation pump 33 is operated in response to the refill command. When the water flow switch 34 is turned on by the start of the operation, the combustion operation control of the combustion system 66 is started and the combustion burner 6 is operated. This combustion operation is performed so that the return temperature detected by the return temperature sensor 35 maintains the set bath temperature. That is, if the return temperature detected by the return temperature sensor 35 is lower than the bath set temperature, the combustion operation is performed, and if it is equal to or higher than the bath set temperature, the combustion operation is stopped.

  The hot water filling control unit 52 first determines whether or not there is remaining hot water in the bathtub B (represented as “remaining hot water” including the remaining water) by the circulation determination, and if it is determined that there is no remaining hot water, for example, In a predetermined stage, the pouring circuit 4 pours water up to a predetermined water level, and if it is determined that there is remaining hot water, the remaining hot water is used to perform a circulating flow rate detection process, and then the remaining hot water amount is calculated. On the basis of the above, the hot water is poured by the pouring circuit 4 to fill the hot water to the predetermined water level. In the circulation determination, as shown in FIG. 3, the circulation pump 33 is operated (step S1), and it is determined whether or not the water flow switch 3 is turned on (step S2). If the water flow switch 3 is not turned on, there is no remaining hot water ( Alternatively, it is determined that the remaining hot water is present (NO in step S2). The pouring is performed by opening the pouring valve 42 and dropping the hot water at a predetermined temperature into the bathtub B through the pouring channel 41 and the recirculation circuit 32 by the combustion operation of the combustion burner 6.

  Next, when it is determined that there is remaining hot water (YES in step S2), the circulating flow rate detection processing unit 53 detects the circulating flow rate of the recirculation circuit 3 using the remaining hot water. FIG. 2 shows a control configuration for only hot water filling and circulating flow rate detection processing, and FIG. 3 is a flowchart for hot water control centering on circulating flow rate detection processing. In addition, it is desirable that the operation of the circulation pump 33 in step S1 described above is continued for a certain period of time to stir the remaining hot water in the bathtub B so as to maintain a uniform temperature. As the circulation flow rate detection process, first, the operation of the circulation pump 33 is maintained as it is, combustion of the combustion burner 6 is started, and bath water is replenished (step S3). Then, the return temperature detected by the return temperature sensor 35 and the forward temperature detected by the forward temperature sensor 36 are recorded. Here, the reason why both the return temperature and the return temperature are detected and recorded during the reheating period is to be used in the subsequent calculation of the remaining hot water amount (step 9).

  When the bath water temperature obtained from the detected return temperature rises to a predetermined target temperature (YES in step S4), the combustion of the combustion burner 6 is stopped (extinguishes) (step S5). At the same time, the detected temperature at the time of extinguishing is recorded and the timer means 531 is started. If the temperature drops by a set temperature difference ΔT (for example, ΔT = 1 ° C. or 2 ° C.) from the detected forward temperature (° C.) at the time of fire extinguishing (YES in step S6), the timer value of the timer means 531 at the time of the temperature drop is set. Output (step S7). This timer value represents a descent time value required for the temperature of the circulating flow at the installation position of the forward temperature sensor 36 to drop by a set temperature difference ΔT from the time when the combustion burner 6 is extinguished. Then, based on the timer value, the corresponding circulation flow value is calculated from the relation table stored in advance in the table storage unit 532, and the calculated circulation flow value is set as the circulation flow value in the recirculation circulation path 32 (step). S8).

  Thus, the circulating flow value detection process is completed, and the circulating flow value can be detected (acquired) without using a directly measuring device such as a flow sensor. In addition, the circulating flow rate detection process can be completed in just a few seconds after starting the circulating flow rate detection process as will be described later, which is about 10 minutes when the circulating flow rate value is grasped by the conventional heat amount calculation by water injection. Even when compared with the required time, the circulating flow rate value can be detected very quickly. Further, since the start of the required timer value is the time when the combustion burner 6 is extinguished, it is possible to accurately grasp the start time, and at the end of the timer value, the detected forward temperature has dropped by the set temperature difference ΔT. Therefore, it is possible to accurately grasp the end of the period, and as a result, it is possible to measure a very accurate value as a timer value to be collated with the relational table, and the corresponding circulation based on the accurate timer value. Since the flow rate value is derived, an accurate circulating flow rate value can be obtained.

  FIG. 4 shows the relationship between the set temperature difference ΔT and the descent time value required for the forward temperature at the installation position of the forward temperature sensor 36 on the downstream side of the reheating heat exchanger 31 to drop by ΔT. This will be described with reference to FIG. The bathtub hot water returned from the bathtub B through the return path 32 a by the combustion operation of the combustion burner 6 is heat-exchanged and heated in the reheating heat exchanger 31, and the hot water having increased in temperature is sent from the reheating heat exchanger 31 to the outgoing path 32 b. The flow to the downstream temperature sensor 36 position. For this reason, the going temperature Th detected by the going temperature sensor 36 gradually increases. When the combustion burner 6 is extinguished at time τ0 while the operation of the circulation pump 33 continues, the going temperature at the position of the going temperature sensor 36 continues to slightly increase in temperature for only a minute time, but turns to a temperature drop at a rapid degree. It will be. When a small temperature difference ΔT is set as the temperature drop, the temperature drop degree becomes steeper as the circulating flow rate becomes larger, and the temperature drop becomes gentler as the circulating flow rate becomes smaller. For this reason, the descent time value required for the temperature drop of the temperature difference ΔT from the fire extinguishing time τ0 is longer than the descent time value Δτ2 when the circulating flow rate is large, and the descent time value Δτ1 when the circulating flow rate is small. It will show the characteristics. From the above, there is a correlation between the descent time value required for the temperature drop by the temperature difference ΔT and the circulation flow rate, and as described in the examples described later, the descent time value, the circulation flow value, and If the relationship table between the two is determined by experiments in advance, the circulation flow rate value can be determined easily, quickly and accurately simply by measuring the descent time value. Regarding the rapidity, the descent time values Δτ1 and Δτ2 indicate that the bath water (circulated hot water) corresponding to the flow volume of the outgoing path 32b in the range from the heat exchanger 31 to the outgoing temperature sensor 36 passes through the position of the outgoing temperature sensor 36. In order to correspond to the descent time value required to finish, the above descent time value measurement is completed in seconds instead of minutes, and the circulation flow value can be calculated very quickly. .

  When the detection of the circulating flow rate value is completed in step S8, the remaining hot water amount is calculated by the hot water filling control unit 52 using this circulating flow rate value (step 9). The remaining hot water amount is calculated by calculating the amount of heat using the detected return temperature, detected forward temperature, and the circulating flow rate value recorded during the reheating period (step S3). That is, the integrated heat quantity given by reheating by the combustion burner 6 is obtained by multiplying the temperature rise width obtained by subtracting the detected return temperature from the detected forward temperature and integrating the circulating flow value according to the elapsed time. And what is necessary is just to calculate the amount of remaining hot water from this integrated calorie | heat amount and the temperature rise of the return temperature (bath hot water temperature) in the same elapsed time.

  If the amount of remaining hot water can be ascertained in the calculation of step S9, the amount of hot water (or amount of water) to be added up to the set water level of the hot water filling for bathtub B can be ascertained. The hot water filling control unit 52 performs the hot water filling operation (step S10).

<Other embodiments>
In addition, this invention is not limited to the said embodiment, Various other embodiments are included. That is, in the said embodiment, although the can with a 1 can 2 channel type hot water heater was shown as an application object of a heating control apparatus, it is not restricted to this, Each of the heat exchanger for hot water heaters and the reheating heat exchanger is each A two-can, two-water channel type water heater equipped with a hot water heater configured to be subjected to heat exchange heating by an independent combustion burner may be applied. In addition, the application object of the present invention relating to the processing for detecting the circulation flow rate value may be at least a circulation circuit in which a heat exchanger heated by a heating source is provided in the middle. The present invention can be applied not only to a circuit but also to other circulation circuits. Furthermore, the present invention may be applied not only to a combustion burner that burns fuel gas as a heating source, but also to a combustion burner that burns liquid fuel such as petroleum, or a device that uses an electric heater as a heating source.

  For the timer value (fall time value required for temperature drop of temperature difference ΔT from the time of fire extinguishing) or the circulating flow value calculated from the relational table based on the timer value in the above embodiment, the outside air temperature Corrections may be made depending on how high or low. For example, an outside air temperature sensor 71 (for example, an F point thermistor; see FIG. 1 or FIG. 2) is installed as an outside air temperature detecting means, and if the outside air temperature detected by the outside air temperature sensor 71 is lower than the reference temperature range, the degree of temperature drop. Therefore, it is considered that the time required for the temperature drop is shortened, so that a positive correction is made to the timer value output from the timer means 531. On the contrary, if the outside air temperature is higher than the reference temperature range, Add negative correction. The correction width may be, for example, plus / minus 0.05 seconds. By adding such correction based on the outside air temperature, it becomes possible to obtain an even higher precision (accuracy) as the circulation flow rate value obtained by the detection process.

  Alternatively, the table storage unit 532 stores a plurality of types of relationship tables that are set in advance to be applied to a plurality of different outside temperatures, and is detected by the outside temperature sensor 71 serving as the outside temperature detecting means. The relationship table to be applied may be changed and set depending on whether the temperature is high or low.

In the above embodiment, in addition, when the predetermined relationships between the fall time value and the circulating flow rate value as a relationship table, sets a plurality of types of relationship table differs depending height whether the temperature of the circulating flow of extinguishing time so as to. That is, for each of a plurality of different temperatures as the temperature of the circulating flow (fluid circulating in the circulation path; bathtub hot water), a relationship table to be applied to the circulating flow at that temperature is set, and these multiple types of relationship tables are set. It is stored in the table storage unit 532 to be your memorial service. Then, during the circulation flow rate detection process, a relation table corresponding to the return temperature is called based on the return temperature detected by the return temperature sensor 35, and the value of the circulation flow rate is calculated from the relation table. Note that the set temperature set in the remote controller 51 may be used as the circulating flow temperature instead of the return temperature. In short, as will be described in detail in the second embodiment, in order to detect the circulating flow rate value with higher accuracy in consideration of the effect of the heat mass (heat capacity) of the heat exchanger 31, the heat mass is used at the time of extinction. A simple understanding is made based on the temperature of the circulating flow, and the correction is made based on the temperature of the circulating flow at the time of extinction. Such correction may be added to the correction based on the outside temperature.

  The relational table stored in the table storage unit 532 may be stored in the table storage unit 532 before shipment from the factory, or may be stored in the table storage unit 532 after the heating device is installed at the use site. Or any of them. Further, after use, the relationship table may be updated and stored in a new one.

  As the relationship table, a relationship curve (including a linear relationship line obtained by approximating the relationship curve to a straight line) may be set as a broken line, an alternate long and short dash line or a solid line in FIG. A mathematical expression that defines such a relationship curve may be set, a numerical table may be set, or any of them may be set. As a relation curve, an approximate expression is determined from the test results obtained by the test as described later using, for example, the least square method, and the coordinate system of the descent time value and the circulation flow rate value is specified based on this approximate expression. Alternatively, the approximate expression itself may be set as a relation table. Also, when the numerical table is set as a relation table and there is no circulating flow value that exactly matches, the circulating flow value can be calculated by linear interpolation between adjacent circulating flow values. Good.

<Example 1>
The way in which the forward temperature detected by the forward temperature sensor 36 changes after the combustion burner 6 is extinguished is tested under various condition settings by changing the combination of the target set temperature and the circulating flow rate. Was measured. And based on the measurement result, the relationship between the value of the circulation flow rate and the descent time value (elapsed time) required to drop the temperature by a predetermined temperature difference ΔT was examined.

  The condition settings tested are as follows. That is, in the state where 100 L (liter) of remaining hot water of about 20 ° C. is stored in the bathtub B using the 1 can / two water channel type hot water bath shown in FIG. 1, the circulation flow rate is 4 L / min, 5 L / Each circulation flow of min, 6L / min, 7L / min, 8L / min, and 9L / min is created, and 33 ° C, 42 ° C, and 48 ° C are set as the set temperature on the remote control, and reheating is performed by the combustion burner 6 It was. That is, for example, the set temperature was set to 33 ° C., and the circulation flow rate was changed to the above-mentioned 6 types of 4 L / min to 9 L / min, and the conditions were set by combining these similarly for the set temperatures of 42 ° C. and 48 ° C. Then, the change in the forward temperature detected by the forward temperature sensor 36 was measured from the time when the initial reheating heating was completed (the combustion burner 6 was extinguished by shutting off the fuel gas supply). The measurement timing was performed at a period of 0.1 second. The measurement results are shown in FIG. FIG. 5 shows the detected temperature at the time of fire extinguishing on the vertical axis and the elapsed time on the horizontal axis. In addition, for example, a change curve illustrated as “33 ° C.-9.0 L / m” in the same figure indicates a change curve when the circulating flow rate is set to 9.0 L / min at a set temperature of 33 ° C. The case where it is heated to approximately 51 ° C. by the combustion heat from the combustion burner 6 to be heated to the set temperature 33 ° C. and then supplied to the bathtub B is shown. According to FIG. 5, after the extinguishing of the combustion burner 6, the going-out temperature shows the same tendency as before the extinguishing until a minute time (for example, 1.0 to 1.5 seconds) elapses, but after that, the temperature rapidly increases. I'm descending. The actual circulation flow value was confirmed using a Karman vortex flowmeter.

  FIG. 6 is a rewrite of the measurement result of FIG. In FIG. 6, the temperature difference from the going-out temperature at the time of fire extinguishing is plotted on the vertical axis, and the elapsed time is plotted on the horizontal axis. According to FIG. 6, the fall time value (elapsed time) required for the temperature drop of ΔT = 1.0 ° C. is in the range of 1.8 to 2.9 seconds, and is required for the temperature drop of ΔT = 2.0 ° C. The fall time value (elapsed time) was in the range of 2.1 to 3.4 seconds. The smaller the value of the circulation flow rate, the larger the descent time value tends to increase, and this tendency is the same as the characteristic of FIG.

  In FIG. 6, the combination of the drop time value and the circulation flow value at the temperature difference ΔT = 1.0 ° C. and the combination of the drop time value and the circulation flow value at the temperature difference ΔT = 2.0 ° C. The measurement results were extracted, and the measurement results extracted for the coordinates where the descent time value (indicated as “elapsed time” in FIG. 7) was set on the vertical axis and the circulation flow rate was set on the horizontal axis were plotted. This is shown in FIG.

  FIG. 7 shows the relationship between various circulating flow rate values and the descent time value (elapsed time) required to drop the temperature by the temperature difference ΔT when circulating at that circulating flow rate. The case of the temperature difference ΔT = 1 ° C. is indicated by a broken line, and the case of the temperature difference ΔT = 2 ° C. is indicated by a solid line. According to this, even if there is a difference between the set temperatures 33 ° C., 42 ° C., and 48 ° C., that is, a difference in the degree of heating by the combustion burner 6, the relationship between the circulation flow rate and the descent time value is represented by a substantially constant relationship curve. It can be seen that the relationship between the circulation flow rate and the descent time value at a certain temperature difference ΔT shows a substantially constant relationship. Therefore, a circulation flow rate-fall time value relationship table (relation curve or numerical table) as shown in FIG. 7 is obtained in advance by testing, and this relationship table is stored in the circulation flow rate detection processing unit 53 (see FIG. 2). In this case, by measuring a timer value (see step S7 in FIG. 3) corresponding to the above descent time value, it is possible to determine and detect the value of the circulating flow rate from the relation table. For example, the temperature difference ΔT = 1. If 2.2 seconds are output as the timer value in the case of ° C., 6.4 L / min can be obtained as the value of the circulating flow rate from the relation table of FIG.

<Example 2>
The second embodiment is different from the first embodiment in that the measurement purpose and the like are the same as those in the first embodiment, but various conditions are measured more precisely than in the first embodiment. That is, as in the first embodiment, various conditions are set by changing the combination of the target set temperature and the circulating flow rate as to how the forward temperature detected by the forward temperature sensor 36 changes after the combustion burner 6 is extinguished. The change in the going-out temperature was measured. And based on the measurement result, the relationship between the value of the circulation flow rate and the descent time value (elapsed time) required to drop the temperature by a predetermined temperature difference ΔT was examined.

  The condition settings tested are as follows. That is, using a can with two water channels and a hot water heater shown in FIG. 1, in a state where 100 L (liter) of remaining hot water of about 20 ° C. is stored in the bathtub B, a predetermined flow rate is maintained under a constant circulation flow rate. The set temperature was set, and the reheating with the combustion burner 6 was performed up to this set temperature. Then, the temperature of the circulating hot water gradually rises due to reheating, and the initial reheating is completed when the return temperature detected by the return temperature sensor 35 reaches the set temperature (the combustion burner is cut off by the supply of fuel gas being cut off). From the time point 6 was extinguished), the change in the forward temperature detected by the forward temperature sensor 36 and the passage of time were monitored. Then, the elapsed time (fall time value) when the detected forward temperature drops by a temperature difference ΔT = 1 ° C. from the time of extinguishing the combustion burner 6 and the elapsed time (fall) when the temperature drop by a temperature difference ΔT = 2 ° C. Time value). The temperature change was measured at a cycle of 0.01 seconds, and the elapsed time was measured at a unit of 0.01 seconds (10 msec unit). The time point at which the temperature drop by the temperature difference ΔT was taken as the point at which the temperature drop by 1 ° C. or 2 ° C., which is the temperature difference ΔT, was detected three times. In addition, the actual circulating flow value was measured with an electromagnetic flow meter capable of measuring with higher accuracy than the Karman vortex flow meter of Example 1, and was measured up to 0.01 L / min with this electromagnetic flow meter.

  In such a measurement test, a combination of a predetermined number of circulating flow rates and three set temperatures (33 ° C., 40 ° C., 48 ° C.) was set, and ΔT = 1 ° C. and a temperature drop of 2 ° C. for each. Time (fall time value) was measured. That is, 13 kinds of circulating flow rates at a set temperature of 33 ° C. (actual values are 4.00, 4.02, 4.91, 4.95, 5.99, 6.04, 7.12, 7.11, 8.04) , 8.03, 8.63, 8.61, 8.60 L / min), 22 kinds of circulating flow rates at a set temperature of 40 ° C. (actual values are 4.03, 4.06, 4.50, 4.51, 4 97, 4.99, 5.48, 5.50, 5.99, 5.99, 6.51, 6.51, 7.03, 7.03, 7.00, 7.48, 7.53 , 7.96, 8.05, 8.48, 8.65, 8.61 L / min), 12 kinds of circulating flow rates at a set temperature of 48 ° C. (actual values are 3.99, 3.99, 4.98, 5) .02, 6.03, 6.01, 7.12, 7.13, 7.98, 8.01, 8.66, 8.66 L / min) for a total of 47 sets Test was carried out.

  FIG. 8 is a graph showing a descent time value measured as an elapsed time until a temperature drop of ΔT = 1 ° C. and 2 ° C. with respect to the coordinates where the elapsed time (fall time value) is set on the horizontal axis and the flow rate is set on the vertical axis. Plots are made at the points of the corresponding measured circulation flow rate values, and a relationship curve representing the relationship between the two is shown. The relational curve shown in FIG. 8 is specified by an approximate expression that assumes a relationship between the circulation flow rate Q and the descent time value τ with a certain basic relational expression and is specified based on the actual measurement value.

That is, as the above basic relational expression, the circulation flow rate Q is expressed by the descent time value τ and the temperature T of the circulating flow at the time of extinction as shown in the following expression (1). Note that a is a predetermined constant.
Q = a / {τ−f (T)} (1)
In this basic relational expression, the circulation flow rate Q and the descent time value τ are in a reciprocal relationship (Q = a / τ) and the denominator related to the descent time value τ is expressed by a function of the temperature T. It is defined as subtracted from the value τ. As a function of the temperature T, a linear function (f (T) = b · T + c) may be used. Substituting this into equation (1) yields the following equation (2).
Q = a / {τ− (b · T + c)} (2)
As the temperature T, the return temperature detected by the return temperature sensor 35 at the time of fire extinguishing may be applied, but the value of the set temperature may be applied for convenience. This is because the heating control is executed such that the return temperature reaches the set temperature, the reheating is finished, and the fire is extinguished. Then, for each of the remaining constants a, b, and c, for the two types of cases of ΔT = 1 ° C. and 2 ° C., for example, based on the measured descent time value and the measured circulation flow value, for example, the minimum What is necessary is just to specify by calculation using a square method and to use as an approximate expression.

  The concept of the above approximate expression is based on the following concept. That is, as described with reference to FIG. 4 for the temperature change characteristics after the fire extinguishing of the combustion burner 6, the timing at which the temperature starts to drop suddenly is delayed when the circulating flow rate is small than when it is large. This is considered to be an effect based on the difference in size of the heat mass (heat capacity) of the heat exchanger 31, and the size of the heat mass can be easily determined by the temperature of the circulating flow at the time of fire extinguishing. Referring to FIG. 8, at the same circulating flow rate, there is a tendency to shift slightly with respect to the right side position in FIG. 8 when the set temperature is high compared to when the set temperature is low, and the shift amount increases as the temperature difference ΔT increases. It shows a tendency to increase. Although the influence of the heat mass due to the temperature of the circulating flow at the time of fire extinguishing may be ignored as in the example of FIG. 7, the circulating flow value detection processing may be performed. In order to perform the process, correction may be added based on the temperature T of the circulating flow at the time of extinguishing in consideration of the influence of the heat mass. For example, a correction term based on the temperature T as in the above formula (1) or formula (2) is taken into account, and a relational curve or a relational expression (approximate expression) corrected based on the temperature T may be set. .

2 Hot water supply circuit 3 Recirculation circuit 5 Controller (heating control device)
6 Combustion burner (heating source)
21 Heat Exchanger for Hot Water Supply 31 Heat Exchanger for Reheating 32 Recirculation Circulation Path 32b Outbound Path (circulation path on the downstream side in the circulation direction)
35 Return temperature sensor 36 Outward temperature sensor (outward temperature detection means)
52 Hot water filling control unit 53 Circulating flow rate detection processing unit 71 Outside air temperature sensor (outside air temperature detecting means)
531 Timer means 532 Table storage section B bathtub

Claims (7)

A heating control device applied to a heating device including a circulation path through which a fluid circulates, a heat exchanger interposed in the circulation path, and a heating source that heats and heats the fluid flowing through the heat exchanger Because
A forward temperature detecting means for detecting the temperature of the forward fluid in the circulation path at a position downstream in the circulation direction from the heat exchanger, and a circulation for detecting the circulation flow rate of the fluid circulated through the circulation path by control processing. A flow rate detection processing unit,
The circulating flow rate detection processing unit includes timer means for measuring an elapsed time value and a table storage unit for storing a predetermined relationship table, wherein the relationship table includes the circulating flow rate of the fluid in the circulation path, and the heating Circulating flow rate detection processing is set in advance with respect to the relationship with the descent time value from when the source heating operation stops until the temperature of the forward fluid detected by the forward temperature detection means drops by the set temperature difference. The heating operation of the heating source is stopped while maintaining the fluid circulation state in the circulation path, while the temperature change of the forward fluid detected by the forward temperature detection means is monitored, and the temperature of the forward fluid is Measured by the timer means the descent time value required to drop the temperature by a set temperature difference from the time when the heating operation was stopped, and based on the measured descent time value from the relation table By indexing the values of the circulation flow rate to respond it is configured to detect, furthermore,
The circulating flow rate detection processing unit has a plurality of types of relationship tables set in advance in the table storage unit to be applied to a plurality of types of heat capacities that are different from each other in heat capacity of the heat exchanger when the heating operation is stopped. stored, that is configured to receive the output of the detection value or the set value representing the heat capacity changes and sets the relationship table to be applied depending upon which the output value,
Pressurized thermal control device, characterized in that. The heating control device according to claim 1,
The said heating apparatus is a heating control apparatus which is a bath pot provided with the reheating circulation path through which bathtub hot water is circulated between a heat exchanger and a bathtub as a circulation path. The heating control device according to claim 2,
The heating device includes a hot water supply circuit in addition to a reheating circulation circuit, and is configured to be heated by a common heating source for a reheating heat exchanger and a hot water heat exchanger. Heating control device that is a hot water heater with water heater. The heating control device according to claim 3,
The circulation flow rate detection processing unit is configured to execute a detection process of a circulation flow rate value in a state in which the remaining hot water is present in the bathtub in the hot water filling control for the bathtub. The heating control device according to claim 3 or 4, wherein
In order to execute the hot water filling control for the bathtub, a hot water filling control unit that calculates the remaining hot water amount in the bathtub is provided.
The hot water filling control unit is configured to calculate a remaining hot water amount using a value of the circulating flow rate detected by the circulating flow rate detection processing unit. The heating control apparatus according to any one of claims 1 to 5,
An outside air temperature detecting means for detecting the outside air temperature,
The circulating flow rate detection processing unit corrects the descent time value measured by the timer means or the circulating flow rate value calculated from the relationship table depending on whether the outside air temperature detected by the outside air temperature detecting means is high or low. A heating control device configured as described above. The heating control apparatus according to any one of claims 1 to 5,
An outside air temperature detecting means for detecting the outside air temperature,
The circulating flow rate detection processing unit stores in the table storage unit a plurality of types of relationship tables that are preset as applied to a plurality of different outside air temperatures, and the level of the outside air temperature detected by the outside air temperature detecting means A heating control device configured to change and set a relation table to be applied.

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