JP5120057B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply apparatus including a hot water supply heat exchanger that exchanges heat between a heat storage fluid stored in a tank and hot water supply water, and an auxiliary heat source device that can reheat the hot water supply water.

  Conventionally, for example, an apparatus described in Patent Document 1 is known as this type of hot water supply apparatus. This hot water supply apparatus connects a heat collector, which is a main heat source, to a hot water storage tank via a circulation pipe through which a heat medium flows, and includes a pressure pump in the middle of a hot water supply pipe connected to the hot water storage tank. Is provided with a branch pipe via a switching valve on the auxiliary heat source (water heater) on the suction side.

In the operation of this conventional hot water supply device, when the switching valve is switched so that hot water from the hot water storage tank flows directly to the inlet side hot water supply pipe of the pressurizing pump, the hot water in the hot water storage tank is used as an auxiliary heat source (hot water heater). Does not flow. On the other hand, when the switching valve is switched so that hot water from the hot water tank flows directly to the branch pipe, the hot water in the hot water tank does not flow directly to the pressurizing pump, but directly to the auxiliary heat source (hot water heater) side. Flowing. Then, the hot water in the hot water storage tank flows to the hot water tap side with the pressurizing pump via the branch pipe together with the hot water preliminarily heated with the hot water heater of the auxiliary heat source before flowing to the pressurizing pump (above, (See paragraphs 0022 and 0023 of Patent Document 1).
JP 10-47764 A

  However, in the conventional hot water supply apparatus, when switching from hot water supply not passing through the auxiliary heat source to hot water supply passing through the auxiliary heat source, there is a problem that cold water is discharged to the hot water tap side at the initial stage of switching. This is because cold water is stopped in the piping between the hot water storage tank and the auxiliary heat source, the piping between the auxiliary heat source and the hot water tap (outlet tap), or the like. The occurrence of the cold water stoppage becomes significant when the hot water supply path via the auxiliary heat source is used in winter or when the auxiliary heat source is not used for a while. When such cold water is suddenly discharged from a hot water tap (outlet tap) such as a shower, for example, a user who thinks that hot water is discharged is surprised and gives the user an unpleasant feeling.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a hot water supply device that does not discharge cold water, which is stopped in a pipe or the like connected to an auxiliary heat source device, to a user. .

  In order to achieve the above object, the following technical means are adopted. That is, the first invention according to the hot water supply apparatus is provided with a main heat source that heats and moves the hot water to the hot water supplied to the hot water terminal, and auxiliary water that is provided to further heat the hot water heated by the main heat source. The auxiliary heat source (4), which is a heat source, and the hot water heated by the main heat source, the flow that passes through the auxiliary heat source device and the flow that does not pass through the auxiliary heat source device, and then rejoins the flow that does not pass through the auxiliary heat source device And a flow rate control means (11) for adjusting the flow rates of both flows and a control device (100) for controlling the operation of the flow rate control means.

  The control device controls the operation of the flow rate control means and adjusts the flow rates of both the flows when a predetermined condition is satisfied, so that the pipes connected to the inside of the auxiliary heat source device and the pipe connected to the auxiliary heat source device are controlled. It is characterized in that the hot water supplied to the hot water supply terminal is mixed after mixing the stationary water staying inside and the hot water supply water heated by the main heat source.

According to the present invention, by controlling the flow rate control valve 11 when a predetermined condition is established, the hot water supply water controlled to an appropriate flow rate can be flowed into the auxiliary heat source device or the like. It can be heated by mixing with hot water on the heat source side. Furthermore, in order to mix this warmed water with hot water that has flowed without passing through the auxiliary heat source, an effect of increasing the temperature of the water is obtained, and after the water is sufficiently warmed, Hot water is discharged from the hot water supply terminal. As a result, it is possible to avoid a situation where the user is bathed in low-temperature stationary water. Therefore, it is possible to provide a hot water supply apparatus that does not discharge cold water, which is stopped in a pipe or the like connected to the auxiliary heat source device, to the user.

The main heat source includes a heating means (1) for heating a heat storage fluid that is heat-exchanged with hot water supplied to a hot water supply terminal, and a tank (2) for storing therein the heat storage fluid heated by the heating means. And a hot water supply heat exchanger (3) for heating the hot water supply water by exchanging heat between the heat storage fluid in the tank and the hot water supply water,
Drive means (9) for adjusting the flow rate of the heat storage fluid flowing through the hot water heat exchanger,
Further, the control device controls the temperature of the hot water to be mixed with the stationary water by further controlling the operation of the driving means when a predetermined condition is satisfied.

  According to this invention, the flow rate of the hot water to be mixed with the stationary water can be adjusted by the flow rate control means, and the temperature of the hot water can be adjusted by controlling the operation of the drive means. For this reason, since the state of the hot water to be mixed with the retained water can be controlled from both the temperature and the flow rate, the retained water can be discharged in a more desired state. Therefore, it is possible to hardly give the user an uncomfortable feeling due to the discharge of the stop water.

The predetermined condition is preferably established when the hot water is being discharged, and when the heat storage fluid in the tank becomes a predetermined temperature or lower. According to this invention, the hot water is transported while gradually warming in the hot water path during the hot water, and discharged from the hot water supply terminal together with the hot water supply water, so that the hot water temperature does not fluctuate and the user feels uncomfortable. Hard to give. Furthermore, since the fluid temperature in the tank is used as a criterion for determining whether or not to take measures to stop the discharge of the retained water, the retained water inside the auxiliary heat source device is supplied to the hot water supply terminal before the fluid temperature in the tank becomes too low. Can be spilled from. As a result, it becomes possible for the auxiliary heat source device to flow out the retained water at a temperature slightly higher than the temperature of the hot water supply water at which reheating starts, and when the auxiliary heat source device starts reheating, the low temperature retained water is discharged Therefore, efficient reheating can be performed.

  Further, the control device further reduces the temperature of the hot water to be mixed with the stationary water to a temperature equal to or lower than the second predetermined temperature, which is lower than the first predetermined temperature, when the stopped water is equal to or higher than the first predetermined temperature. Thus, the operation of the drive means (9) is controlled, and then the operation of the flow rate control means is controlled to mix the hot water supply water with the retained water.

  When the temperature of the stationary water is high, if this is mixed with hot water supply water and discharged, hot water that feels hot to the user is provided. Therefore, according to the present invention, by controlling the temperature of the hot water to be mixed with the stationary water to be lowered and then mixing, it is possible to eliminate the fact that the stationary water circulates in the pipe at a high temperature. It is possible to avoid hot water that is unexpectedly warm from the terminal.

  The main heat source includes heating means (1) for heating water to boil it to hot water, and a hot water storage tank (2) for storing hot water boiled by the heating means as hot water supply water. Connected to the flow control means.

  According to this invention, the hot water flowing out from the hot water storage tank is divided into a flow that does not pass through the auxiliary heat source device and a flow that passes through the auxiliary heat source device and then merges again into a flow that does not pass through the auxiliary heat source device by the flow rate control means. Thus, in the hot water supply apparatus in which the main heat source is a direct hot water discharge type, it is possible to prevent the user from hitting the low-temperature stop water directly and to discharge the stop water without causing discomfort to the user.

  In addition, the code | symbol in the bracket | parenthesis of each said means is an example which shows a corresponding relationship with the specific means of embodiment mentioned later.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. In addition to the combination of the parts that clearly indicate that the combination is possible in each embodiment, the embodiments may be partially combined even if they are not clearly indicated unless there is a problem with the combination. It is also possible.

(First embodiment)
1st Embodiment which is one Embodiment of this invention is described according to FIGS. FIG. 1 is a schematic diagram showing a schematic configuration of a hot water supply apparatus according to the present embodiment. FIG. 2 is a block diagram showing a control configuration according to the hot water supply apparatus.

  The hot water supply apparatus of the present embodiment includes a main heat source that moves heat to hot water supplied to a hot water supply terminal and heats it, and an auxiliary heat source that further heats hot water supplied by the main heat source. . The main heat source includes heating means for heating a heat storage fluid that is heat-exchanged with hot water supplied to a hot water supply terminal, a hot water storage tank 2 that stores therein the heat storage fluid heated by the heating means, and a hot water storage tank 2 And a hot water supply heat exchanger 3 for performing heat exchange between the heat storage fluid and the hot water supply water to heat the hot water supply water.

  This hot water supply device is, for example, a hot water storage type heat pump type hot water supply device, which is mainly used for general household use, and heat storage hot water stored in the hot water storage tank 2 and hot water supply water are heated by a hot water supply heat exchanger 3. Replace and supply the heated hot water supply water to a hot water supply terminal (hand-washing faucet, currant, bath, etc.) provided in the kitchen, washroom, bathroom, etc., and when the predetermined condition is met, the auxiliary heat source 4 supplies hot water supply water. Furthermore, it has a function of adjusting the temperature by heating.

  As shown in FIG. 1, the hot water supply apparatus includes a heat pump unit 1 that is a heating unit that heats and exchanges heat with a high-temperature and high-pressure refrigerant, a hot water storage tank 2 that stores the hot water heated by the heat pump unit 1, Heat exchange is performed between the heat storage circulation circuit 6 provided so that the low-temperature water in the lower part of the hot water storage tank 2 flows out and is heated by the heat pump unit 1 and returns to the upper part of the hot water storage tank 2, and the hot water for heat storage and the hot water supply water. A hot water supply heat exchanger 3, an auxiliary heat source device 4 that can supplementarily heat the hot water supply water heated by the hot water supply heat exchanger 3, a control device 100 that controls the operation of the hot water supply device, It has.

  The heat pump unit 1 is configured such that at least refrigeration cycle functional components such as a compressor, a heat storage heat exchanger, an expansion valve, an evaporator, and an accumulator are connected in a ring shape. The heat pump unit 1 constitutes a supercritical heat pump cycle in which, for example, carbon dioxide having a low critical temperature is used as a refrigerant, whereby the refrigerant pressure on the high pressure side becomes equal to or higher than the critical pressure of the refrigerant.

  When the heat pump cycle is constituted by a supercritical heat pump, hot water having a temperature higher than that of a general heat pump cycle, for example, about 85 ° C. to 90 ° C. can be stored in the hot water storage tank 2. The heat pump cycle mainly performs a boiling operation in which hot water in the hot water storage tank 2 is boiled using late-night power in the late-night time zone, which is inexpensively set.

  In the heat storage circulation circuit 6, an incoming temperature thermistor for detecting the temperature of water supplied to the water-refrigerant heat exchanger, which is a heat storage heat exchanger in the heat pump unit 1, and a water-refrigerant heat exchanger outlet A boiling temperature thermistor for detecting the boiling temperature and an electric pump are provided. Then, the detected temperature signal of each thermistor is output to the control device 100.

  The hot water storage tank 2 is a vertically long container that stores hot water, which is a heat storage fluid that heats hot water, and is made of a metal having excellent corrosion resistance, for example, stainless steel. Water can be kept warm for a long time. In addition, the heat storage fluid is mainly composed of water, and may contain a preservative, an antifreezing agent, LLC, and the like. In addition, the heat storage fluid may be a mixture of heat storage materials having cross specific heat, such as microcapsules, dispersed in water and mixed, or may be mixed in a thriller form.

  The hot water in the hot water storage tank 2 is circulated by the operation of the electric pump of the heat storage circulation circuit 6. Thus, the hot water in the hot water storage tank 2 heated by the heat storage heat exchanger is sent to the upper part of the hot water storage tank 2 through the heat storage circulation circuit 6, so that the upper side in the hot water storage tank 2 is moved to the lower side. The heat is sequentially stored so as to form a plurality of temperature layers.

  The hot water supply heat exchanger 3 includes a primary side passage 3a and a secondary side passage 3b provided so that fluids flowing inside each other exchange heat. The primary side passage 3a is a flow path that communicates with the hot water storage tank 2 and through which hot water in the hot water storage tank 2 flows. The secondary side passage 3b is a flow path in which an upstream end is connected to the water supply pipe 10, and a downstream end is connected to the hot water supply pipe 13, and a flow path through which hot water supplied to the hot water supply terminal flows. is there. The primary side passage 3a and the secondary side passage 3b may have any form in which heat is exchanged between fluids flowing through the passages. For example, you may comprise by the double pipe structure in which one channel | path is formed in an inner side pipe | tube and the other channel | path is formed in the outer side pipe | tube which covers the outer side of an inner side pipe | tube. Moreover, it is preferable that the hot water supply heat exchanger 3 is an opposed heat exchanger in which the flow directions of the fluids flowing through the primary side passage 3a and the secondary side passage 3b are opposed to each other.

  The hot water storage tank 2 is connected to the primary side passage 3a so as to form a primary side circulation circuit 8 that is a circulation passage with the primary side passage 3a of the heat exchanger 3 for hot water supply. The primary side circulation circuit 8 is connected to a lead-out port provided at the uppermost part of the hot water storage tank 2, and detects the heat exchanger inlet temperature in a flow path connecting the lead-out port and the primary side passage 3a. A primary heat exchanger inlet temperature thermistor 18 is provided.

  Further, the primary side circulation circuit 8 is connected to an introduction port provided at the lowermost part of the hot water storage tank 2, and the hot water storage from the primary side passage 3 a is connected to a flow path connecting the introduction port and the primary side passage 3 a. A primary-side circulation return temperature thermistor 19 that detects the outlet temperature of the primary-side heat exchanger of the heat-storage fluid flowing out toward the lower part of the tank 2, and the heat-storage fluid is forcibly circulated to the primary-side circulation circuit 8. And a circulation pump 9 which is a heat storage fluid drive means. The temperature signals detected by the primary heat exchanger inlet temperature thermistor 18 and the primary circulation return temperature thermistor 19 are input to the input circuit of the control device 100.

  Upstream of the water supply pipe 10 is connected to a water pipe, and city water (tap water) is introduced into the secondary passage 3b of the heat exchanger 3 for hot water supply. The water supply pipe 10 is provided with a flow rate detector 16 and a water supply temperature thermistor 20. The flow rate detector 16 is detection means for detecting a flow rate (secondary flow rate) in the direction of the secondary passage 3b, and the feed water temperature thermistor 20 detects the temperature of city water, and the detected flow rate signal and temperature signal. Is input to the input circuit of the control device 100.

  The hot water supply pipe 13 is a pipe that connects the outlet of the secondary side passage 3b of the hot water supply heat exchanger 3 and a hot water supply terminal (hand-washing faucet, currant, bath, etc.) to the kitchen, washroom, bathroom, and the like. A hot water supply temperature thermistor 22 for detecting a hot water supply temperature and a flow rate counter 24 are provided on the downstream side of the hot water supply pipe 13. The hot water temperature signal and the flow rate signal detected by the hot water temperature thermistor 22 and the flow rate counter 24 are input to the input circuit of the control device 100.

  The hot water supply pipe 13 includes a secondary side outlet temperature thermistor 21 (secondary outlet temperature detection) that detects the temperature of hot water at the outlet of the secondary side passage 3b of the hot water supply heat exchanger 3 (heat exchanger secondary outlet temperature). Device). The detected heat exchanger secondary outlet temperature is input to the input circuit of the control device 100. Further, the hot water supply pipe 13 includes a branch portion where the hot water supply pipe 13 branches to the auxiliary heat source passage 15 on the downstream side of the secondary outlet temperature thermistor 21, and the flow control valve 11 is provided at this branch portion. Is provided.

  The flow rate control valve 11 can divert hot water flowing from the outlet of the secondary side passage 3b of the hot water supply heat exchanger 3, and can further control the flow rate ratio of the diverted flow. It is also a valve. In other words, the flow rate control valve 11 divides the hot water supply water into a flow that does not pass through the auxiliary heat source device 4 and a flow that passes through the auxiliary heat source device 4 and then merges again with the aforementioned one flow. Depending on the degree of opening, it is also a heat source switching means capable of switching between heating hot water using only the main heat source and reheating using the auxiliary heat source. That is, the flow control valve 11 can switch the hot water supply water that has flowed out of the secondary side passage 3b to flow through either the hot water supply pipe 13 side or the auxiliary heat source side passage 15 side, and to flow through both. The flow ratio can be adjusted by dividing the flow.

  In this way, in the present hot water supply device, the control device 100 controls the operation of the flow rate control valve 11 so that the hot water supply water passes through the auxiliary heat source device 4 according to the amount of heat stored in the hot water storage tank 2 constituting the main heat source. Switch whether or not. That is, when the amount of heat of the main heat source is insufficient (for example, when the hot water storage tank 2 has a small amount of high-temperature water and a large amount of medium-temperature water is stored), a flow control valve is used to supplement the amount of heat by the auxiliary heat source device 4. 11 is switched to the auxiliary heat source unit 4 side, and the auxiliary heat source unit 4 is operated to reheat the hot water supply water. Further, the control device 100 not only sets the flow rate control valve 11 on either the hot water supply pipe 13 side or the auxiliary heat source side passage 15 side to a 100% opening degree, but also sets both opening degrees to a range of 0 to 100%. The temperature of the hot water flowing through the auxiliary heat source passage 15 is adjusted by adjusting the flow rate ratio so that the hot water supply water flows in both directions. The hot water supply apparatus supplies hot water at a desired temperature to a hot water supply terminal such as a shower, a hot water tap, and a bath by performing such control.

  In the middle of the auxiliary heat source passage 15, there is provided an auxiliary heat source device 4 for reheating the hot water supply water flowing through the auxiliary heat source side passage 15, and the downstream end of the auxiliary heat source passage 15 joins the hot water supply pipe 13. ing. The auxiliary heat source device 4 has a heat generating part and a heat exchanging part that receives heat from the heat generating part, and the auxiliary heat source passage 15 passes through the heat exchanging part. The water passing through the auxiliary heat source passage 15 absorbs heat from the heat generating part when passing through the heat exchanging part. On the surface of the auxiliary heat source passage 15 passing through the heat exchanging part of the auxiliary heat source unit 4, a heat exchanging part temperature sensor 23 capable of detecting the temperature of the water flowing through the auxiliary heat source unit 4 is provided. The hot water supply temperature signal detected by the heat exchanger temperature sensor 23 is input to the input circuit of the control device 100.

  The auxiliary heat source device 4 is not particularly limited as long as it is a device capable of heating the hot water supply water passing therethrough. As the auxiliary heat source 4, for example, a small gas water heater that heats hot-water supply water that passes through the inside using a combustion flame of fuel such as gas, a device that uses a combustion part that burns kerosene as fuel, and a hot water storage tank. A heat storage fluid as a heat source, an electric heater using electricity, or the like can be employed.

  The water supply pipe 10 branches before the secondary passage 3 b of the hot water supply heat exchanger 3, and the branched pipe merges with the hot water supply pipe 13. A pipe from the branch part of the water supply pipe 10 to the junction part of the hot water supply pipe 13 is a secondary side bypass passage 14 that bypasses the hot water supply heat exchanger 3. A hot water supply mixing valve 12 is provided at the junction of the secondary bypass passage 14 and the hot water supply pipe 13.

  This hot water supply mixing valve 12 is a temperature adjustment valve that adjusts the temperature of hot water discharged to the hot water supply terminal side, and by adjusting the opening area ratio between the hot water supply pipe 13 side and the secondary side bypass passage 14 side, Control is performed to adjust the mixing ratio of the hot water supply water heated by the heat exchanger 3 and the city water to the set temperature. The control device 100 controls the hot water mixing valve 12 based on the temperature set by the remote controller 110 or the like and the temperature information detected by the feed water temperature thermistor 20, the secondary outlet temperature thermistor 21 and the hot water temperature thermistor 22. To do.

  The outer wall surface of the hot water storage tank 2 is provided with a plurality of hot water storage thermistors 17 which are water temperature sensors for detecting the amount of hot water for storing hot water and the temperature of the hot water storage. Five thermistors TH1, TH2, TH3, TH4, and TH5 are arranged in order from the top. The detected temperature signals of these five thermistors are respectively input to the input circuit of the control device 100, and can detect the temperature of the heat storage fluid and the amount of hot water at each water level. Moreover, TH1 located in the uppermost part among the plurality of hot water storage thermistors 17 can detect the temperature of hot water discharged from the hot storage fluid.

  An indirect tank 5 for supplying city water in the hot water storage tank 2 is placed on the top surface of the hot water storage tank 2. A water supply pipe through which city water flows and an escape pipe are connected to the upper part of the indirect tank 5, and a circulation pipe 7 connected to the lower part of the hot water storage tank 2 is connected to the lower part of the indirect tank 5. . A water level sensor is provided in the indirect tank 5, and water is automatically supplied into the indirect tank 5 by a detection signal of the water level sensor transmitted to the control device 100. When the water flowing through the water supply pipe is stored in the indirect tank 5, the water in the indirect tank 5 flows into the lower part of the hot water storage tank 2 through the circulation pipe 7, and excess water is released through the pipe for escape. It is discharged to the outside through.

  As shown in FIG. 2, the control device 100 includes an input circuit to which signals from various switches on the remote controller 110, flow rate detector 16, various thermistors 17 to 23, and communication signals from the flow rate counter 24 are input. A microcomputer that executes various calculations using signals from the input circuit, and a heat pump unit 1, an auxiliary heat source device 4, a circulation pump 9, a flow rate control valve 11, a hot water supply mixing valve 12 and the like based on the calculation by the microcomputer And an output circuit for outputting a communication signal to be controlled. The microcomputer incorporates a ROM or RAM as storage means and has a preset control program and an updatable control program.

  During winter or when the auxiliary heat source 4 has not been used for a while, water should stop in the piping between the hot water storage tank 2 and the auxiliary heat source 4 or the piping between the auxiliary heat source 4 and the hot water outlet of the hot water supply terminal. There is. When this stopped water is cold cold water and a sufficient amount of stored hot water is not secured in the hot water storage tank 2 as the main heat source, if a shower is used, the auxiliary heat source 4 Control using reheating is performed. At this time, first, the low-temperature stop water flows out from the shower outlet, so the user may be exposed to cold water.

Therefore, in order to avoid such a situation, the present hot water supply apparatus adjusts the opening degree of the flow rate control valve 11 when a predetermined condition is satisfied, and passes the heated hot water supply water through the auxiliary heat source 4. The flow is divided into a flow that does not pass through the auxiliary heat source device 4, and the two are merged in the downstream region, so that the remaining water is mixed with hot water and warmed, and then flows out to the hot water supply terminal.

  Next, the operation of the hot water supply apparatus having the above configuration will be described. First, boiling control of the hot water supply device will be described. When the hot water supply switch of the remote controller 110 is turned on by the user, the control device 100 mainly uses a heat pump in the late-night time zone (for example, the time zone from 23:00 on the current day to 7 o'clock on the next day) where the power rate is inexpensive. The unit 1 is operated, the heat storage fluid in the hot water storage tank 2 is heated, and a necessary amount of heat is stored.

  That is, when the hot water storage thermistor detects that the necessary amount of heat does not remain in the hot water storage tank 2 the next day in the midnight power time zone, the control device 100 instructs the heat pump unit 1 to start boiling. Upon receiving the command, the heat pump unit 1 starts driving the circulation pump of the heat storage circulation circuit 6 after starting the compressor, and the low-temperature water taken out from the lower part of the hot water storage tank 2 is about 70 to 90 ° C. with a water-refrigerant heat exchanger. The hot water is returned to the hot water storage tank 2 from the upper part of the hot water storage tank 2 through the heat storage circulation circuit 6, and the hot water is stored sequentially by stacking from the upper part of the hot water storage tank 2. When the hot water storage thermistor 17 detects that the required amount of heat has been stored, the control device 100 commands the heat pump unit 1 to stop boiling, and the heat pump unit 1 stops the compressor and also stops the circulation pump 9. Then, the boiling operation is finished.

  Next, in a series of hot water supply control related to the hot water supply apparatus having the above-described configuration, an example of control that is performed when hot water is supplied to the auxiliary heat source device 4 will be described with reference to FIGS. First, FIG. 3 is a main flowchart showing the operation of the hot water supply apparatus of the first embodiment. The present hot water supply apparatus stops when the predetermined condition predetermined in the series of hot water supply control is satisfied (for example, when a first predetermined condition and a second predetermined condition described later are satisfied). Implement cold water countermeasure control that warms the water to a temperature that does not make the user uncomfortable and then discharges the hot water.

  When the power source of the hot water supply apparatus is turned on, the flow rate control valve 11 serving as the flow rate control means is open to the hot water outlet side so as to open the passage of the hot water supply pipe 13 100%, for example. Furthermore, low-temperature water stops in the auxiliary heat source passage 15 and the passage in the auxiliary heat source unit 4. Then, in step 10, the control device 100 is in the hot water supply waiting time at which the hot water supply terminal has not yet been discharged, and the temperature detected by the second thermistor TH2 from the top among the plurality of hot water storage thermistors 17. Is equal to or less than a value obtained by adding a predetermined temperature Tα to the hot water supply target temperature set by the user (hot water supply target temperature + Tα) (also referred to as condition 2). Here, the hot water supply target temperature is a temperature 5 ° C. higher than the hot water supply set temperature of the hot water discharged from the hot water supply terminal. The predetermined temperature Tα is, for example, 15 ° C.

  If the control device 100 determines that the condition of step 10 is not satisfied, then, at step 20, the current hot water is being discharged and the temperature detected by the hot water storage thermistor TH1 is set by the user. It is determined whether or not both conditions are satisfied (also referred to as condition 5) that is equal to or lower than a value obtained by adding a predetermined temperature Tα to the hot water supply target temperature (target hot water supply temperature + Tα). Both of these conditions are first predetermined conditions for determining whether or not to execute cold water countermeasure control that does not cause hot water in the auxiliary heat source device 4 or the like to be discharged at a low temperature. That is, if the determination in step 20 is yes, the cold water countermeasure control in step 40 can be performed through the determination process in step 30. Conversely, if the control device 100 determines that the condition of step 20 is not satisfied, it skips the cold water countermeasure control of step 40 and performs normal hot water supply control.

  If it is determined that the first predetermined condition in step 20 is satisfied, the control device 100 further determines in step 30 a second predetermined condition for determining whether or not the cold water countermeasure control can be performed. In step 30, it is determined whether or not the retained water inside the auxiliary heat source device 4 is in a cooled state. That is, the control device 100 determines whether or not the temperature inside the auxiliary heat source device 4 is lower than a predetermined first predetermined temperature. At this time, for example, a value detected by the heat exchanger temperature sensor 23 is used as the temperature inside the auxiliary heat source device 4. This first predetermined temperature is a temperature used to determine that the water stay is not in a relatively hot pool of heat, and the user does not feel uncomfortable even if the water is discharged toward the user. The maximum temperature is set.

  If the control device 100 determines that the second predetermined condition of Step 30 is satisfied (the stopped water is not in a hot state), the control device 100 regards that the stopped water is at a low temperature and cannot take out hot water from the hot water supply terminal as it is. Then, cold water countermeasure control is performed to warm the hot water by mixing the remaining water with hot water supply water in the pipe (step 40). As will be described later, the cold water countermeasure control is performed according to the subroutines shown in FIGS. 4 to 6, and the operations of the flow control valve 11 and the circulation pump 9 are appropriately controlled.

  On the other hand, if the control device 100 determines in step 30 that the second predetermined condition is not satisfied (it is equal to or higher than the first predetermined temperature), there is a possibility that the retained water is in a hot pool state. If the hot water is discharged together with the hot water supply water, there is a possibility that the user may feel uncomfortable. Therefore, the temperature is controlled after lowering the temperature of the stationary water (step 32 and step 34).

  In step 32, the control device 100 controls the rotational speed of the circulation pump 9 to a low rotational speed, and sets the target temperature of the heat exchanger secondary outlet temperature (hereinafter also referred to as heat exchange outlet temperature) from the first predetermined temperature. Also, control is performed so as to lower the temperature to a second predetermined temperature or less determined at a low temperature. For example, the target temperature is 5 to 10 ° C. lower than the normal target temperature. Further, in the control of step 32, for example, the circulating pump 9 is operated so as to lower the target temperature until the temperature inside the auxiliary heat source device 4 actually falls below a certain temperature (below the second predetermined temperature). You may make it repeat the process to make. In this control, first, the secondary side water heat-exchanged with the primary side fluid in the hot water supply heat exchanger 3 is brought into a lukewarm water state. Next, in step 34, by controlling the flow rate control valve 11 so that the passage on the auxiliary heat source unit 4 side is opened 100%, this warm water is caused to flow into the auxiliary heat source unit 4 and the retained water is stored in a hot state. Allow it to cool until it runs out and then pour out the hot water. Thereby, it can be avoided that warm hot water is unexpectedly discharged from the hot water supply terminal.

  The cold water countermeasure control in step 40 is performed according to a subroutine shown in FIG. As shown in FIG. 4, the control device 100 first controls the opening degree of the flow rate control valve 11 by feedforward control (step 41), and at the same time, controls the rotational speed of the circulation pump 9 by feedback control. (Step 42). And cold water countermeasure control is implemented by performing repeatedly control of step 41 and step 42 until the determination process of step 43 is satisfy | filled.

  The control in step 41 is performed according to the control characteristic diagram shown in FIG. FIG. 5 is a control characteristic diagram used in the feedforward control of the flow control valve 11 in step 41 of FIG. This control characteristic diagram shows the relationship between the mixing ratio of the stationary water with respect to the total flow rate by the flow rate control valve 11 and the opening degree of the auxiliary heat source side passage of the flow rate control valve 11, and is stored in the control device 100 in advance. It is a predetermined table. The opening degree of the flow control valve 11 is an opening degree that is determined in accordance with the mixing ratio due to a characteristic unique to the flow control valve 11 to be used. The control device 100 determines the opening degree of the auxiliary heat source side passage of the flow control valve 11 according to this characteristic diagram, and controls the flow control valve 11 to the determined opening degree. The mixing ratio on the horizontal axis shown in FIG. 5 is calculated based on Equation 1 below.

(Formula 1)
Mixing ratio = (hot-water supply set temperature-auxiliary heat source internal temperature) / (heat exchange outlet temperature-auxiliary heat source internal temperature) x 100
Here, the hot water supply set temperature is a set temperature of hot water discharged from the hot water supply terminal. The internal temperature of the auxiliary heat source device is an actual value detected by the heat exchanging portion temperature sensor 23, and the heat exchange outlet temperature is an actual value detected by the secondary side outlet temperature thermistor 21.

  The control device 100 obtains the opening degree of the auxiliary heat source device side passage of the flow control valve 11 from the mixing ratio calculated by substituting the actual measurement value into Equation 1 and the control characteristic diagram of FIG. As shown in FIG. 5, the flow rate control valve 11 is configured such that the opening degree of the auxiliary heat source device side passage decreases with the mixing ratio as the heat exchange outlet temperature increases.

  The control in step 42 is performed according to a subroutine shown in FIG. FIG. 6 is a flowchart showing a subroutine of the rotational speed control (feedback control) of the circulation pump 9 in step 42 of FIG. In this subroutine, the process of increasing or decreasing the rotational speed of the circulation pump 9 is repeated until the determination process of step 422 is satisfied. That is, in step 422, until the difference between the heat exchanger outlet temperature and the heat exchanger outlet target temperature (for example, the hot water supply set temperature + 5 ° C.) is within the allowable deviation (for example, within 0.1 ° C.), Feedback control of the number of rotations of the pump 9 is executed. For example, when the heat exchange outlet temperature is higher as the difference between the two exceeds 0.1 ° C., the control device 100 controls to reduce the rotational speed of the circulation pump 9 in step 421, and conversely the heat exchange outlet. If the temperature is low, control is performed in step 421 to increase the rotational speed of the circulation pump 9. The rotational speed of the circulation pump 9 is controlled such that the difference between the heat exchange outlet temperature and the heat exchange outlet target temperature falls within a predetermined allowable deviation while applying feedback in this way.

  The control device 100 performs the feedforward control of the opening degree of the flow rate control valve 11 and the feedback control of the rotational speed of the circulation pump 9, whereby the internal temperature of the auxiliary heat source and the target temperature thereof are determined in step 43. When it is determined that the difference from (for example, the hot water supply set temperature + 5 ° C.) is within the allowable deviation (for example, within 0.5 ° C.), the cold water countermeasure control is completed.

  In this way, the remaining water inside the auxiliary heat source device 4 flows through the auxiliary heat source passage 15 in a state where the hot water is mixed with hot water having a target temperature that is higher by a predetermined temperature than the hot water set temperature and the temperature rises. Since it joins with the hot water supply water of the said temperature in the piping 13 for hot water, the temperature rises further and it is discharged to the hot water supply terminal. And this cold water countermeasure control of the stationary water is continued until the temperature inside the auxiliary heat source becomes higher than the hot water supply set temperature, so that there is a low temperature in the inside of the auxiliary heat source etc. and the pipe connected thereto. Water is no longer present, and low-temperature stationary water can be reliably removed.

  On the other hand, if the control apparatus 100 determines that the condition of the previous step 10 is satisfied, the flow control valve 11 is moved through the passage on the auxiliary heat source unit 4 side in step 12 without performing the cold water countermeasure control in step 40. Control to open 100%. Next, the control device 100 performs control to switch the opening degree of the flow control valve 11 to the hot water side (fully open the hot water supply pipe 13 and fully close the auxiliary heat source passage 15 side) (step 14). This switching control is performed according to a subroutine shown in FIG. FIG. 7 is a flowchart showing a control subroutine for switching the flow rate control valve 11 to the outlet side in step 14 of FIG.

  As shown in FIG. 7, in step 141, the controller 100 adds the predetermined temperature Tβ to the hot water supply target temperature set by the user as the temperature detected by the second hot water storage thermistor TH 2 from the top (hot water supply target). It is determined whether or not both conditions of higher than (temperature + Tβ) and the flow rate counter of the hot water are less than a predetermined value (also referred to as condition 1) are satisfied. The hot water supply target temperature is, for example, 5 ° C. higher than the hot water supply set temperature, and the predetermined temperature Tβ is, for example, 20 ° C. The discharged water flow rate counter is a flow rate signal detected by the flow rate counter 24.

  If it is determined that both conditions of step 141 (condition 1) are satisfied, the control device 100 returns the flow rate control valve 11 to the hot water supply side, so that in step 142 the flow rate control valve 11 is a passage on the hot water supply pipe 13 side. Is controlled to 100%. Conversely, if it is determined that both conditions of step 141 are not satisfied, the control device 100 does not return the flow rate control valve 11 to the hot water side, and ends this control while leaving the auxiliary heat source side open.

  Next, an outline of conditions when various states of the hot water supply device are transitioned in the control related to the flow control valve 11 of the present application will be described with reference to FIG. As shown in FIG. 8, the right side of the figure shows a state where there is a sufficient amount of hot water stored in the hot water storage tank 2 and the opening of the flow control valve 11 is open to the hot water outlet side, and the left side of the figure is the hot water storage tank 2. This shows a state in which there is not enough hot water storage inside and the opening of the flow control valve 11 is open to the auxiliary heat source unit 4 side.

  Further, the left side of the figure further includes “a state with medium hot water” and “a state without medium hot water” in the hot water storage tank 2. The “state with intermediate temperature water” is a state where there is not enough hot water storage in the hot water storage tank 2 but intermediate temperature water exists. Condition 6 that is satisfied when the state is changed from “the state where there is no medium-temperature water” to “the state where there is intermediate-temperature water” is that the temperature detected by the hot water storage thermistor TH2 is a value obtained by adding a predetermined temperature Tγ to the average water supply temperature (average water supply temperature) + Tγ), and the hot water supply flow rate is larger than a value obtained by adding a predetermined flow rate to the required hot water supply flow rate. The predetermined temperature Tγ is 20 ° C., for example. This required hot water supply flow rate is calculated by Equation 2.

(Formula 2)
Necessary hot water flow rate = minimum heating capacity of auxiliary heat source / {target hot water supply temperature− (average water supply temperature + Tγ)}
In addition, the minimum heating capability of the auxiliary heat source device is a value determined by the capability of the heat exchanging part of the auxiliary heat source device 4 to be used. For example, when the auxiliary heat source 4 is a gas combustion type, the capacity of the gas combustion unit.

  The “state without intermediate hot water” is a state where there is not enough hot water storage in the hot water storage tank 2 and there is no intermediate hot water. Condition 7 that is satisfied when the state is changed from “the state where there is intermediate temperature water” to “the state where there is no intermediate temperature water” is that the temperature detected by the hot water storage thermistor TH 1 + Tγ) or less, or the hot water supply flow rate is less than the required hot water supply flow rate.

  The right side of the figure further includes “a state in which hot water from the hot water storage tank 2 is waiting” and “a state in which hot water is being discharged from the hot water storage tank 2”. Condition 3 in which “a state waiting for hot water from the hot water storage tank 2” is satisfied is when hot water from the hot water storage tank 2 is not detected and hot water is stopped. Condition 4 in which “a state in which hot water is being discharged from the hot water storage tank 2” is satisfied is a case in which hot water from the hot water storage tank 2 is detected.

  When the condition 1 in the above-described step 141 is satisfied, the state “waiting for hot water from the hot water storage tank 2” from the “state in which the flow control valve 11 opens the auxiliary heat source device 4” on the left side of the drawing to the right side in the drawing. ”. When the above-described condition 2 in Step 10 is satisfied, the “state in which the flow rate control valve 11 opens the auxiliary heat source 4 side” on the left side of the figure from “the state of waiting for hot water from the hot water storage tank 2” on the right side of the figure. ”.

  When the condition 5 is satisfied, the state shifts from “the state in which hot water is being discharged from the hot water storage tank 2” on the right side of the drawing to “the state in which the flow control valve 11 opens the auxiliary heat source device 4” on the left side of the drawing. Condition 5 is that the temperature detected by the hot water storage thermistor TH1 is equal to or lower than a value obtained by adding a predetermined temperature Tα to the hot water supply target temperature (hot water supply target temperature + Tα).

  Next, an outline of the control specifications of the circulation pump 9 in each state of the hot water supply apparatus will be described with reference to FIG. The operation of the circulating pump 9 described here is performed corresponding to each state shown in FIG. First, when the hot water is discharged in the state shown on the right side of FIG. 8, only the amount of stored hot water in the hot water storage tank 2 is used as a heat source, and the flow control valve 11 is controlled so as to fully open the passage on the hot water side. The operation of the pump 9 is controlled by adjusting the rotational speed so that the target temperature (heat exchange outlet target temperature) becomes the hot water supply set temperature.

  In addition, when the hot water is discharged in the state of “with intermediate warm water” shown on the left side of FIG. 8, although there is intermediate warm water, the amount of stored hot water is not sufficient, so the stored hot water amount and the auxiliary heat source 4 are used as heat sources, and the flow rate control is performed. The valve 11 is controlled so that the passage of the auxiliary heat source device 4 is fully opened, and the operation of the circulation pump 9 is rotated so that the target temperature (heat exchange outlet target temperature) becomes a value obtained by adding 20 ° C. to the average feed water temperature. The number is adjusted and controlled.

  In addition, when the hot water is discharged in the “no intermediate temperature water” state shown on the left side of FIG. 8, since the intermediate temperature water and the stored hot water cannot be used, only the auxiliary heat source device 4 is used as a heat source, and the flow control valve 11 is an auxiliary device. Control is performed to fully open the passage of the heat source device 4, and the circulation pump 9 is stopped.

  Next, the operation of the hot water in the “state with medium hot water” that can be performed after the above-described cold water countermeasure control is performed will be described with reference to FIG. FIG. 10 is a flow chart showing a subroutine for target temperature fluctuation countermeasure control that is performed when hot water is discharged using the medium temperature water in the hot water storage tank 2 after step 40 (cold water countermeasure control) in FIG. .

  When the above condition 6 is satisfied after the cold water countermeasure control in step 40 described above is performed, the circulation pump 9 has the heat exchange outlet target temperature set to a value obtained by adding 20 ° C. to the average feed water temperature as described above. Therefore, the temperature fluctuates with respect to the heat exchange outlet target temperature (hot water supply set temperature + 5 ° C.) set by the cold water countermeasure control, and there is a concern that the user may feel uncomfortable when the hot water is discharged.

  Therefore, the control device 100 first starts the operation of the auxiliary heat source unit 4 in step 50 and controls the flow rate control valve 11 to fully open the passage on the side of the auxiliary heat source unit, and in step 51, the target temperature of the circulation pump 9 is reached. A process of setting a certain heat exchange outlet target temperature to the hot water supply set temperature is executed. In order to finally set the heat exchange outlet target temperature to a value obtained by adding 20 ° C. to the average water supply temperature, in step 51, the heat exchange outlet target temperature is first set to a high temperature, and the temperature of the hot water supply water after heat exchange is high. It is intended to be. In step 52, the control device 100 continues the operation by lowering the heat exchange outlet target temperature by a predetermined temperature Δt every predetermined time (for example, by 1 ° C. every 1 second). A process of gradually lowering the temperature is executed. The processing in step 52 continues until the heat exchange outlet target temperature reaches a value obtained by adding 20 ° C. to the average feed water temperature.

  Then, the control device 100 adjusts the opening area ratio between the hot water supply piping 13 side and the secondary bypass passage 14 side of the hot water supply mixing valve 12 so that the temperature detected by the hot water supply temperature thermistor 22 becomes the hot water supply set temperature. Thus, hot water supply water and city water are mixed as necessary, and the opening of a flow rate adjustment valve (not shown) is adjusted so that a set flow rate is obtained. Thereby, hot water of the conditions desired by the user is discharged to the hot water supply terminal.

  When performing hot water using the auxiliary heat source device 4 after the cold water countermeasure control is performed, the target temperature fluctuation can be suppressed by implementing such a target temperature fluctuation countermeasure control for the circulation pump 9. It is possible to provide a hot spring that makes it difficult for the user to feel the temperature change.

  Also, by this control, when the amount of stored hot water in the hot water storage tank 2 is low and a sufficient amount of heat cannot be obtained by the hot water supply heat exchanger 3, the hot water supplied by the auxiliary heat source device 4 is used together to perform the desired hot water discharge by the user. This can eliminate unnecessary driving and reduce running costs.

  The effects provided by the hot water supply apparatus according to this embodiment will be described below. The present hot water supply apparatus includes a main heat source that transfers heat to hot water supplied to a hot water supply terminal and heats it, an auxiliary heat source 4 that is provided to further heat hot water heated by the main heat source, and a main heat source The water for hot water heated in step 1 is divided into a flow that does not pass through the auxiliary heat source device 4 and a flow that passes through the auxiliary heat source device 4 and then merges again with a flow that does not pass through the auxiliary heat source device 4. And a control device 100 for controlling the operation of the flow control valve 11.

  Then, when the predetermined condition is satisfied, the control device 100 controls the operation of the flow control valve 11 and adjusts the flow rates of both flows when the predetermined condition is satisfied, whereby the auxiliary heat source device 4 is controlled. The hot water supplied to the hot water supply terminal is mixed after the stationary water staying inside the pipe and the pipe connected to the auxiliary heat source device 4 are mixed with hot water supplied by the main heat source.

According to this, by controlling the flow rate control valve 11 when a predetermined condition is satisfied, the remaining water is mixed with hot water supply water and warmed and then discharged, so that the user unexpectedly bathes the low-temperature stationary water. Can be avoided. Therefore, even when the stationary water is cold water, the stationary water can be discharged so as not to cause discomfort to the user.

  The main heat source includes a heat pump unit 1 that heats a heat storage fluid that is heat-exchanged with hot water supplied to a hot water supply terminal, a hot water storage tank 2 that stores therein a heat storage fluid heated by the heat pump unit 1, and hot water storage. A hot water supply heat exchanger 3 that heats the hot water supply water by exchanging heat between the heat storage fluid in the tank 2 and the hot water supply water. Further, the present hot water supply apparatus includes a circulation pump 9 that adjusts the flow rate of the heat storage fluid flowing through the hot water supply heat exchanger 3. And the control apparatus 100 controls the temperature of the hot water for mixing with a stationary water by further controlling the action | operation of the pump 9 for circulation when a predetermined condition is satisfied.

  According to this, the flow rate of the hot water to be mixed with the stationary water can be adjusted by the flow control valve 11, and the temperature of the hot water can be adjusted by the control of the circulation pump 9. For this reason, since the state of the hot water supply water is controlled from both sides of temperature and flow rate, the retained water can be discharged in a more desired state. Therefore, in the hot water supply apparatus in which the main heat source is an indirect type, it is possible to prevent the user from being directly exposed to the low-temperature stop water, and to discharge the stop water without causing discomfort to the user.

  Further, in the case of a hot water supply apparatus in which the main heat source is an indirect type, even when the hot water storage temperature is lowered, it is possible to carry out a hot water supply operation that uses the medium-temperature water reaching the upper part of the hot water storage tank 2 without waste. Furthermore, by lowering the circulating return temperature, it is possible to suppress an increase in the feed water temperature to the heat pump unit 1 and to provide an improvement in the coefficient of performance of the heat pump unit 1 and a reduction in running cost. Moreover, in this hot water supply apparatus, it is possible to perform a good hot water supply operation without providing a medium temperature water take-out pipe or a mixing valve for collecting the medium temperature water in the hot water storage tank 2, so that the number of parts can be reduced and the product cost can be reduced. .

The predetermined condition is preferably established when the hot water is being discharged, and when the heat storage fluid in the hot water storage tank 2 becomes a predetermined temperature or lower. According to this, the stop water is mixed with the hot water supply water in the piping during the hot water, and is conveyed while gradually raising the temperature in the hot water supply route, and discharged from the hot water supply terminal. Therefore, it is possible to discharge the stop water that is kind to the user without fluctuation of the tapping temperature. Further, in order to determine whether or not to implement the countermeasure for stopping water discharge using the fluid temperature in the hot water storage tank 2, the internal temperature of the auxiliary heat source 4 and the like before the fluid temperature in the hot water storage tank 2 becomes too low. Stop water can be discharged to the hot water supply terminal. Thereby, it becomes possible to make the said stationary water flow out at the temperature a little higher than the temperature of the hot water for which the auxiliary heat source device 4 starts reheating. Therefore, when the auxiliary heat source device 4 starts reheating, the low-temperature stationary water has already been discharged, so that efficient reheating can be performed.

  In addition, when the stay water is equal to or higher than the first predetermined temperature, the control device 100 sets the temperature of the hot water to be mixed with the stop water to be equal to or lower than the second predetermined temperature lower than the first predetermined temperature. Thus, the operation of the circulation pump 9 is controlled, and then the operation of the flow control valve 11 is controlled so that the hot water supply water is mixed with the retained water.

  According to this control, it is possible to prevent the hot water pool water from flowing through the piping by mixing the hot water supply water to be mixed with the stationary water so as to lower the temperature. Therefore, it can be avoided that hot water that is too warm is unexpectedly discharged from the hot water supply terminal, and the user is not uncomfortable.

(Second Embodiment)
2nd Embodiment demonstrates the hot water supply apparatus which is another form with respect to the hot water supply apparatus demonstrated in the said 1st Embodiment, and cold water countermeasure control accompanying this. FIG. 11 is a schematic diagram illustrating a schematic configuration of the hot water supply apparatus according to the present embodiment. FIG. 12 is a main flowchart showing the operation of the hot water supply apparatus. FIG. 13 is a flowchart showing a subroutine of cold water countermeasure control in step 40a of FIG. This hot water supply apparatus is different from the hot water supply apparatus shown in FIG. 1 in that hot water stored in the hot water storage tank 2 is directly discharged from a hot water supply terminal as hot water supply water. As a result, the hot water supply apparatus does not include the hot water supply heat exchanger 3 and the primary side circulation circuit 8 and the members associated therewith. Instead, the hot water storage tank 2 is connected to the water supply pipe 10 at the bottom. The introduction pipe 25 for introducing city water is connected. In FIG. 11, the same reference numerals as those shown in FIG. 1 denote the same constituent elements that exhibit the same operations and effects, and the description thereof is as described in the first embodiment.

  Next, the operation of the hot water supply apparatus will be described with reference to FIGS. Further, in the main flowchart of FIG. 12, steps denoted by the same reference numerals as those in the drawing shown in FIG. 3 perform the same processing as in FIG. 3, and each part has the same operation and effect. The description is as described in the first embodiment.

  Therefore, the cold water countermeasure control in step 40a will be described below. As shown in FIG. 13, the control device 100 first controls the opening degree of the flow control valve 11 by feedforward control (step 41a). And this cold water countermeasure control is implemented by repeatedly performing the control of step 41 until the determination process of step 43 is satisfied.

  The control in step 41a is performed according to the control characteristic diagram similar to that shown in FIG. The control device 100 determines the opening degree of the auxiliary heat source side passage of the flow control valve 11 according to this characteristic diagram, and controls the flow control valve 11 to the determined opening degree. However, the mixing ratio is calculated based on Equation 3 below.

(Formula 3)
Mixing ratio = (hot-water supply set temperature-auxiliary heat source internal temperature) / (tank outlet temperature-auxiliary heat source internal temperature) x 100
Here, the tank outlet temperature is the temperature of hot water flowing out of the tank detected by the tank outflow temperature thermistor 18a.

  The control device 100 obtains the opening degree of the auxiliary heat source device side passage of the flow control valve 11 from the mixing ratio calculated by substituting each actual measurement value into Equation 3 and the control characteristic diagram of FIG.

  The control device 100 repeats the above feedforward control of the opening degree of the flow control valve 11 until the determination process in step 43 is satisfied, and in step 43, the auxiliary heat source device internal temperature and its target temperature (for example, a hot water supply set temperature + 5 ° C.) If it is determined that the difference from the above is within the allowable deviation (for example, within 0.5 ° C.), the cold water countermeasure control is completed.

  In this way, the remaining water inside the auxiliary heat source device 4 flows through the auxiliary heat source passage 15 in a state of being mixed with the hot water for hot water flowing out from the hot water storage tank 2 and rising in temperature, and again in the hot water supply pipe 13. In order to merge with the hot water supply water, the temperature rises further and the hot water is discharged to the hot water supply terminal. And this cold water countermeasure control of the stationary water is continued until the temperature inside the auxiliary heat source becomes higher than the hot water supply set temperature, so that there is a low temperature in the inside of the auxiliary heat source etc. and the pipe connected thereto. Water is no longer present, and low temperature water can be reliably removed.

  The effects provided by the hot water supply apparatus according to this embodiment will be described below. The main heat source of the hot water supply apparatus includes a heat pump unit 1 that heats water to boil it to hot water, and a hot water storage tank 2 that stores hot water boiled by the heat pump unit 1 as hot water supply water. And the hot water storage tank 2 is connected to the flow control valve 11 by piping.

  According to this configuration, the hot water flowing out of the hot water storage tank 2 is rejoined by the flow control valve 11 into a flow that does not pass through the auxiliary heat source device 4 and a flow that does not pass through the auxiliary heat source device 4 after passing through the auxiliary heat source device 4. The stationary water and the hot water supply water can be merged in the pipe, mixed, and discharged. Therefore, in a hot water supply apparatus in which the main heat source is a direct hot water type, it is possible to prevent the user from being directly exposed to low-temperature stationary water, and to discharge the stationary water without causing discomfort to the user.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, step 43 in each of the above embodiments may be replaced with the following determination process. That is, by controlling the flow rate control valve 11, the time may be measured from the time when hot water is supplied through the auxiliary heat source device 4, and the cold water countermeasure control may be terminated when a predetermined time has elapsed. The predetermined time is, for example, an experimental value obtained by an evaluation experiment using a master machine that is the same machine as the hot water supply apparatus, and is stored in advance in a program. The predetermined time may be variable after the product is installed by operating a dip switch or the like provided in the device.

  Thus, by ending the cold water countermeasure control by the timer mechanism by the elapse of a predetermined time, there is no heat exchanger temperature sensor 23, and the temperature of the water in the auxiliary heat source unit 4 or the auxiliary heat source passage 15 cannot be measured. Even in this case, a hot water supply device that reliably flows out of the hot water supply terminal in a state where hot water is mixed with the hot water for hot water can be obtained.

  Moreover, in each said embodiment, you may implement step 41 and step 41a not by feedforward control but by feedback control which makes hot water supply preset temperature target temperature.

  In the first embodiment, the target temperature (target temperature in step 422) in the rotational speed control of the circulation pump 9 may be set to a higher temperature. In this case, by adjusting the opening degree of the downstream hot water supply mixing valve 12, the hot water supply water having a high temperature is mixed with tap water to lower the temperature to adjust the hot water supply set temperature, and then the hot water is discharged.

  In the first embodiment, the target temperature (target temperature in step 422) in the rotational speed control of the circulation pump 9 is set to a value obtained by adding 5 ° C. to the hot water supply set temperature. May be. For example, as a reference in the case of making it variable, the target temperature is made variable according to the opening degree of the auxiliary heat source side passage of the flow control valve 11. Specifically, when the opening degree of the auxiliary heat source side passage of the flow control valve 11 changes to 10%, 12%, 14%, and 16%, the target set temperature is added to the hot water supply set temperature by 1 ° C., respectively. And a value obtained by adding 2 ° C to the hot water supply set temperature, a value obtained by adding 3 ° C to the hot water set temperature, and a value obtained by adding 4 ° C to the hot water set temperature.

  Moreover, the subroutine (control which switches the flow control valve 11 to the hot water side passage fully open) of the said 1st Embodiment is implemented after the cold water countermeasure control of step 40 is implemented in the main flowchart shown in FIG. You may be made to do.

It is the schematic diagram which showed schematic structure of the hot water supply apparatus which concerns on 1st Embodiment of this invention. It is the block diagram which showed the structure which concerns on control of the hot water supply apparatus of 1st Embodiment. It is the main flowchart which showed the action | operation of the hot water supply apparatus of 1st Embodiment. It is the flowchart which showed the subroutine of the cold water countermeasure control in step 40 of FIG. FIG. 5 is a control characteristic diagram used in feedforward control of the flow control valve 11 in step 41 of FIG. 4. FIG. 5 is a flowchart showing a subroutine for rotational speed control (feedback control) of circulation pump 9 in step 42 of FIG. 4. FIG. 6 is a flowchart showing a subroutine for switching control of the flow control valve 11 in step 14 of FIG. 3. It is the figure which put together the conditions in which each state changes in control of the flow control valve 11 of this application. It is the figure which showed the outline | summary of the control specification of the circulation pump 9 in every state of this application. FIG. 4 is a flowchart illustrating a target temperature fluctuation countermeasure control subroutine that is performed when hot water is discharged using medium temperature water in the hot water storage tank 2 after step 40 (cold water countermeasure control) in FIG. 3. It is the schematic diagram which showed schematic structure of the hot water supply apparatus which concerns on 2nd Embodiment. It is the main flowchart which showed the action | operation of the hot water supply apparatus of 2nd Embodiment. It is the flowchart which showed the subroutine of the cold water countermeasure control in step 40a of FIG.

Explanation of symbols

1 ... Heat pump unit (heating means)
2 ... Hot water storage tank (tank)
3 ... Heat exchanger for hot water supply 4 ... Auxiliary heat source 9 ... Pump for circulation (drive means)
11 ... Flow control valve (flow control means)
100 ... Control device

Claims (5)

A main heat source that transfers heat to the hot water used in the hot water supply terminal,
An auxiliary heat source device (4) which is an auxiliary heat source provided to further heat the hot water supply water heated by the main heat source;
The hot water supply water heated by the main heat source is divided into a flow that does not pass through the auxiliary heat source device and a flow that passes through the auxiliary heat source device and then rejoins the flow that does not pass through the auxiliary heat source device, and Flow rate control means (11) for adjusting the flow rates of both flows;
A control device (100) for controlling the operation of the flow rate control means;
With
The control device is connected to the inside of the auxiliary heat source device and to the auxiliary heat source device by controlling the operation of the flow rate control means and adjusting the flow rates of both flows when a predetermined condition is satisfied. A hot water supply apparatus for mixing hot water staying in a pipe with hot water for hot water heated by the main heat source and then discharging the hot water to the hot water supply terminal. The main heat source is
Heating means (1) for heating a heat storage fluid to be heat-exchanged with hot water supplied to the hot water supply terminal;
A tank (2) for storing therein the heat storage fluid heated by the heating means;
A hot water supply heat exchanger (3) for performing heat exchange between the heat storage fluid in the tank and the hot water supply water to heat the hot water supply water,
Drive means (9) for adjusting the flow rate of the heat storage fluid flowing through the hot water supply heat exchanger;
The said control apparatus controls the temperature of the said hot-water supply water mixed with the said stationary water by further controlling the action | operation of the said drive means, when predetermined conditions are satisfied. Hot water supply device. 3. The hot water supply apparatus according to claim 2, wherein the predetermined condition is established when the hot water is being discharged and when the heat storage fluid in the tank becomes a predetermined temperature or lower.   The control device further includes a second predetermined temperature that is lower than the first predetermined temperature when the retained water is equal to or higher than a first predetermined temperature. The operation of the drive means (9) is controlled to be as follows, and then the operation of the flow rate control means is controlled to mix the hot water supply water with the detention water. Water heater.   The main heat source includes a heating means (1) for heating water to boil it into hot water, and a hot water storage tank (2) for storing hot water boiled by the heating means as hot water supply water. The hot water supply apparatus according to claim 1, wherein the tank is connected to the flow rate control means.

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