JP6401464B2 - Heat pump hot water storage system - Google Patents

Description

  The present invention relates to a heat pump hot water storage type hot water supply apparatus that supplies hot water using hot water boiled by a heat pump type heating means stored in a hot water storage tank.

  Conventionally, in this type of heat pump hot water storage type hot water supply device, it is provided in the middle of a hot water storage tank for storing hot water and a heating circulation circuit for circulating hot water from the lower part of the hot water storage tank to the upper part of the hot water storage tank to heat the hot water in the hot water storage tank. A heat pump type heating means, and a boil-up control means for operating the heat pump type heating means to perform a boil-up operation when the hot water storage temperature of the hot water storage tank becomes lower than a predetermined boiling start start temperature in the daytime period. When the temperature suddenly drops, there is one that changes the predetermined boiling start determination temperature to a higher temperature.

Japanese Patent No. 3498671

  However, in this conventional system, even if the boiling increase operation is started when the temperature suddenly drops, the amount of hot water stored in the hot water storage tank has already greatly decreased. There was a problem that there was a high risk of running out of hot water in time.

To achieve the above object, the present invention provides a hot water storage tank for storing hot water, a water supply pipe connected to the lower part of the hot water storage tank, a hot water discharge pipe connected to the upper part of the hot water storage tank, and the hot water storage tank from the lower part of the hot water storage tank. A heating circuit that circulates hot water in the upper part, a heat pump type heating means that is provided in the middle of the heating circuit and that heats the heated hot water so as to match the boiling target temperature, and a plurality of the hot water storage tanks are provided. A hot water storage temperature sensor for detecting the hot water storage temperature, and when the hot water storage temperature sensor detects that the hot water storage amount in the hot water storage tank satisfies a predetermined boiling start condition in a specific time zone, the heat pump heating means is operated. Control means for performing a reheating operation for increasing the amount of stored hot water, the control means at the start of the specific time period or the reheating operation And to change the predetermined reheating start condition stored hot water temperature sensor located on top of the plurality of stored hot water temperature sensor at the end in response to the hot water storage temperature detected.

Also, a hot water storage tank for storing hot water, a water supply pipe connected to the lower part of the hot water storage tank, a hot water pipe connected to the upper part of the hot water storage tank, and a heating circulation for circulating hot water from the lower part of the hot water storage tank to the upper part of the hot water storage tank. A circuit, heat pump heating means for heating the heated hot water provided in the heating circulation circuit so as to coincide with the boiling target temperature, and a plurality of hot water storage temperatures for detecting the hot water temperature provided in the hot water storage tank a sensor, and a boiling target temperature recognizing means for recognizing the boiling target temperature, when it is detected that the hot water storage amount of the hot water storage tank by the hot water storage temperature sensor satisfies a predetermined reheating start condition at certain times and control means for performing additional boiling operation to increase the amount of hot water storage by operating the heat pump heating means, said control means, said boiling th And to change the predetermined reheating start condition raised the boiling temperature recognition means recognizes in accordance with the target temperature.

  In addition, when the hot water storage temperature or the boiling target temperature is equal to or higher than a predetermined value, it is assumed that a specific hot water temperature sensor among the plurality of hot water temperature sensors is equal to or lower than a predetermined temperature, and the hot water storage start temperature is used. Alternatively, when the boiling target temperature is lower than the predetermined value, it is determined that the hot water storage temperature sensor provided at a position lower than the specific hot water temperature sensor when the temperature is equal to or higher than the predetermined value has become equal to or lower than the predetermined temperature. The predetermined boiling start condition is changed in accordance with the hot water storage temperature or the boiling target temperature so as to set the increase start condition.

  In addition, when the hot water storage temperature or the boiling target temperature is equal to or higher than a predetermined value, it is assumed that a specific hot water temperature sensor among the plurality of hot water temperature sensors is equal to or lower than a predetermined temperature, and the hot water storage start temperature is used. Alternatively, when the boiling target temperature is lower than the predetermined value, the heating start condition is that the specific hot water storage temperature sensor is equal to or lower than the predetermined temperature lower than the predetermined temperature when the specific hot water temperature sensor is equal to or higher than the predetermined value. Thus, the predetermined boiling increase start condition is changed according to the hot water storage temperature or the boiling target temperature.

  According to the present invention, when the hot water storage temperature or the boiling target temperature is lower than the predetermined value, the amount of hot water discharged from the hot water storage tank increases, so there is a high possibility of hot water outbreak. Since the start-up condition is changed so that the timing is earlier, the possibility of hot water running out can be reduced.

Schematic configuration diagram of one embodiment of the present invention Flow chart for explaining the operation of the same embodiment Flowchart for explaining the operation of another embodiment

Next, a heat pump hot water storage type hot water supply apparatus according to an embodiment of the present invention will be described with reference to the drawings.
1 is a hot water storage tank unit, 2 is a heat pump unit constituting a heat pump type heating means, 3 is a hot water tap, 4 is a bathtub, and 5 is a remote controller.

<Hot water storage tank unit 1>
6 is a stainless steel hot water storage tank for storing hot water, 7 is a water supply pipe for supplying water to the bottom of the hot water storage tank 6, 8 is a hot water discharge pipe for discharging hot water from the top of the hot water storage tank 6, and 9 is a water supply bypass pipe branched from the water supply pipe 7. 10 is a mixing valve that mixes hot water from the hot water discharge pipe 8 and water from the water supply bypass pipe 9, 11 is a hot water supply pipe that guides the hot water mixed by the mixing valve 10 to the hot water tap 3, and 12 is hot water that flows through the hot water supply pipe 11. , A hot water supply temperature sensor for detecting the temperature of hot water flowing through the hot water supply pipe 11, a water supply temperature sensor for detecting the temperature of hot water flowing through the water supply pipe 7, and 15, a side surface of the hot water storage tank 6. A hot water storage temperature sensor that is provided in plural above and below to detect hot water storage temperature, 16 is a pressure reducing valve that is provided in the middle of the water supply pipe 7 to reduce the water supply pressure, and 17 is provided in communication with the upper part of the hot water storage tank 6. Swelling of hot water Overpressure relief for releasing overpressure by a is valve.

  Reference numeral 18 denotes a bath heat exchanger made of a stainless steel tube wound in a serpentine shape and disposed at the upper part of the hot water storage tank 6, and 19 is a bath circulation that connects the bathtub 4 and the bath heat exchanger 18 so that the bath water can circulate. The circuit, 20 is a bath circulation pump that circulates the bath water, 21 is a bath bypass pipe that bypasses the bath circulation circuit 19, and 22 is provided at a branch point or a junction of the bath circulation circuit 19 with the bath bypass pipe 21. Bath three-way valve that switches between circulating or bypassing the bath heat exchanger 18, 23 is a bath temperature sensor that detects the temperature of the bath water, 24 is a running water switch that detects that a flow rate of a certain amount or more has flowed, 25 Is a water level sensor that detects the water level in the bathtub 4 by detecting pressure.

  26 is a hot water pipe that branches from the hot water supply pipe 11 and communicates with the bath circulation circuit 19, 27 is a hot water on / off valve that opens and closes the flow path of the hot water pipe 26, and 28 detects the flow rate of hot water flowing through the hot water pipe 26. This is a hot water filling flow sensor.

  Reference numeral 29 denotes a heating circuit that connects hot water to the bottom of the hot water storage tank 6 and the heat pump unit 2 and the upper part of the hot water storage tank 6 so that hot water can circulate, and 30 denotes a hot water flow rate sensor 12 15. The detection values of the bath temperature sensor 23, the running water switch 24, and the water level sensor 25 are input to control the operation of the mixing valve 10, the bath circulation pump 20, the bath three-way valve 22, and the hot water on / off valve 27, and the heat pump unit 2 The hot water storage control means is connected to the remote controller 5 so that necessary information can be transmitted and received. Here, the hot water storage control means 30 has a logic circuit such as an MPU and controls the operation according to a program stored in advance while referring to the memory.

<Heat pump unit 2>
31 is a compressor that compresses the refrigerant, 32 is a water heat exchanger in which the refrigerant from the compressor 31 is circulated on the primary side and the secondary side is connected to the heating circuit 29, and 33 is a refrigerant that has flowed out of the water heat exchanger 32. The decompression expansion valve 34 decompresses and expands the refrigerant which has been decompressed and expanded by the decompression expansion valve 33 to become a low temperature and low pressure, and 35 represents the compressor 31, the water heat exchanger 32, the decompression expansion valve 33 and the evaporator. 34 is a refrigerant circulation circuit that connects the refrigerant to the refrigerant 34, and 36 is a blower that blows air as a heat source to the evaporator 34.

  CO2 refrigerant is used for the refrigerant circuit 35, and city water can be heated to an arbitrary temperature in the range of 65 ° C to 90 ° C.

  37 is a heating circulation pump provided in the heating circulation circuit 29 on the inlet side of the water heat exchanger 32, 38 is a discharge temperature sensor for detecting the temperature of the refrigerant discharged from the compressor 31, and 39 flows into the water heat exchanger 32. An incoming water temperature sensor for detecting the temperature of the water to be heated, 40 is a boiling temperature sensor for detecting the temperature of hot water heated by the water heat exchanger 32, 41 is an outside air temperature sensor for detecting the outside air temperature, and 42 is a discharge temperature sensor 38. The detection values of the incoming water temperature sensor 39, the boiling temperature sensor 40, and the outside air temperature sensor 41 are input to control the operation of the compressor 31, the decompression expansion valve 33, the blower 36, and the heating circulation pump 37, and the hot water storage tank unit 1 It is a heating control means connected to the hot water storage control means 30 so that necessary information can be transmitted and received. Here, the heating control means 42 has a logic circuit such as an MPU and controls the operation according to a program stored in advance while referring to the memory.

<Remote controller 5>
43 is a dot-matrix liquid crystal display unit that displays various information related to hot water supply (hot water set temperature, bath set temperature, amount of remaining hot water in the tank, hot water supply device operating state, date and time, etc.), 44 is hot water set temperature, bath set temperature, A cross key for setting a hot water filling set amount, 45 is a bath automatic key for performing bath automatic operation, 46 is a reheating key for performing bath water reheating operation, and 47 is an operation state of the hot water supply device. The remote control means connected to the hot water storage control means 30 of the hot water storage tank unit 1 so as to be able to transmit and receive necessary information is controlled so that the display unit 43 displays information corresponding to the operation of each operation key. is there. Here, the remote control means 47 has a logic circuit such as an MPU and controls the operation according to a program stored in advance while referring to the memory.

<Hot-water supply operation>
Next, operation during hot water supply will be described. When the hot-water tap 3 is opened, water from the water supply pipe 7 flows into the bottom of the hot water storage tank 6, and hot water at the top of the hot water storage tank 6 flows out from the hot water supply pipe 8, and from the water supply bypass pipe 9 by the mixing valve 10. It is mixed with water and flows out from the hot water supply pipe 11. When the hot water supply flow sensor 12 detects the start of hot water supply, the hot water storage control means 30 feedback-controls the opening of the mixing valve 10 so that the hot water temperature detected by the hot water temperature sensor 13 coincides with the set hot water temperature. Hot water supply at a hot water supply set temperature is performed until the stopper 3 is closed.

  At this time, the hot water storage control means 30 calculates the hot water amount (heat amount) consumed for the hot water supply from the hot water supply flow rate, the hot water supply temperature, and the hot water supply temperature, and integrates and stores the hot water supply load for the day. And the hot water storage control means 30 memorize | stores the integrated hot-water supply load for several days (here 7 days) over several days (here 7 days) every day.

<Bath operation>
Next, a bath operation when the bath automatic key 45 of the remote controller 5 is operated will be described. When the bath automatic key 45 is operated, the hot water storage control means 30 drives the bath circulation pump 20 with the bath three-way valve 22 on the side of the bath bypass pipe 21 and determines whether the running water switch 24 detects running water. The presence or absence of remaining hot water in the bathtub 4 is detected.

  When it is confirmed that the running water switch 24 is not turned ON, the hot water on / off valve 27 is opened and the mixing valve 10 is controlled so as to reach the bath set temperature with no remaining hot water in the bathtub 4. Start tensioning.

  When the hot water flow sensor 28 counts the hot water set amount, the hot water on / off valve 27 is closed, and then the bath circulation pump 20 is driven to confirm that there is running water with the running water switch 24, and the bath temperature sensor 23 When the temperature of the bath water to be detected is lower than the bath set temperature, the bath three-way valve 22 is switched to the bath heat exchanger 18 side to perform the bath water reheating operation, and the bath water temperature rises to the bath set temperature. The remote controller 5 notifies the completion of hot water filling.

  At this time, the hot water storage control means 30 calculates the hot water amount consumed by the hot water filling (heat amount) from the hot water flow rate, the hot water temperature, and the hot water temperature, and accumulates and stores the hot water load for the day.

  On the other hand, when there is remaining hot water of the previous day in the bathtub 4 when the bath automatic key 45 is operated or when the reheating key 46 is operated, the flowing water switch 24 is used to check whether there is remaining hot water. Is detected, the bath three-way valve 22 is switched to the bath heat exchanger 18 side due to the remaining hot water, the bath water is retreated, and the bath water temperature detected by the bath temperature sensor 23 becomes the bath set temperature. When it reaches, the driving of the bath circulation pump 20 is stopped, and the completion of the chasing is notified by the remote controller 5.

<Boiling operation>
Next, the boiling operation will be described.
When the start time of the midnight time zone comes, the hot water storage control means 30 predicts the hot water supply load on the next day from the stored accumulated hot water supply loads for the past plural days, and calculates the target hot water storage amount. The current hot water storage amount of the hot water storage tank 6 detected by the hot water storage temperature sensor 15 is subtracted from the target hot water storage amount, and the boiling target amount to be heated during the midnight time zone is calculated.

Also, the hot water storage control unit 30 includes a storage and have been integrated hot water supply load of the last double several days, determines the boiling target temperature and a temperature detected by the water temperature sensor 14 or the outside air temperature sensor 41, the water heating target temperature Then, the required boiling time is calculated from the calculated boiling target amount, the feed water temperature, and the heating capacity of the heat pump unit 2 stored in advance as numerical values. The boiling start time is calculated by tracing the required boiling time from the end time of the midnight time zone.

  When the boiling start time arrives, the hot water storage control means 30 outputs an instruction to start the boiling operation to the heating control means 42, and the heating control means 42 has a temperature detected by the boiling temperature sensor 40. The compressor 31, the decompression expansion valve 33, the blower 36, and the heating circulation pump 37 are driven so as to coincide with the target heating temperature, and the boiling operation by the heat pump cycle is started.

  When the hot water storage temperature sensor 15 at the lowermost part of the hot water storage tank 6 detects a predetermined boiling end temperature or more, it is determined that the boiling has ended, and the hot water storage control means 30 issues an instruction to stop the boiling operation to the heating control means 42. The heating control means 42 stops driving of the compressor 31, the decompression expansion valve 33, the blower 36, and the heating circulation pump 37 and stops the heating operation by the heat pump cycle. The boiling operation is stopped when the end time of the midnight time zone comes before the boiling is completed.

<Boiling operation>
Next, the boiling increase operation will be described based on the flowchart of FIG.
When the end time of the midnight time zone, which is the start time of the specific time zone, is reached, the hot water storage control means 30 confirms the current hot water storage amount detected by the hot water temperature sensor 15 (step S1), and according to the hot water storage amount and the hot water supply load. Subtracted from the target hot water storage volume calculated in this step to calculate the shortage, and from this shortage, the boiling target temperature, the feed water temperature, and the heating capacity, the time required to boil the shortage in the daytime period (Predicted boiling increase time) is calculated (step S2).

  In the following step S3, the hot water storage control means 30 confirms the hot water storage temperature detected by the hot water storage temperature sensor 15 located at the uppermost part of the hot water storage tank 6, and the hot water storage temperature is lower than a predetermined value (here 75 ° C.). If it is lower than the predetermined value, the process proceeds to step S4, where the condition for starting the boiling increase operation is set to a predetermined boiling start condition 1, and if it is equal to or greater than the predetermined value, the process proceeds to step S5. The condition for starting the boiling increase operation is defined as a predetermined boiling increase start condition 2.

  Here, the boiling start condition 1 is that the fourth hot water storage temperature sensor 15 below the hot water storage tank 6 is below 50 ° C., and the boiling start condition 2 is that of the hot water storage tank 6. The condition that the third hot water storage temperature sensor 15 from the top falls below 50 ° C. is used as a condition for starting the heating operation, and the boiling starting condition 1 is started when the amount of hot water discharged from the hot water storage tank 6 is smaller. Therefore, it is set as a condition that it is easier to start boiling up than in boiling starting condition 2.

  Next, in step S6, it is confirmed whether or not there is a predicted boiling time. If there is a predicted boiling time, the process proceeds to step S7 with Yes, and the boiling start condition determined in step S4 or step S5 is set. Monitor whether it is true.

  When the amount of heat in the hot water storage tank 6 is consumed by hot water supply or bath operation and the boiling start condition is satisfied (Yes in step S7), the hot water storage control means 30 outputs an instruction to start the boiling increase operation to the heating control means 42. Then, the heating control means 42 drives the compressor 31, the decompression expansion valve 33, the blower 36, and the heating circulation pump 37 so that the temperature detected by the boiling temperature sensor 40 coincides with the boiling target temperature, and the heat pump cycle. The boiling increase operation is started (step S8). At this time, the hot water storage control means 30 measures the operating time of the boiling increase operation and subtracts it from the predicted boiling increase time.

  Then, the hot water storage control unit 30 monitors whether or not the boiling stop condition is satisfied by the boiling operation (step S9), and when the boiling stop condition is satisfied, the hot water storage control unit 30 issues an instruction to stop the boiling operation. The heating control means 42 outputs to the heating control means 42, and the heating control means 42 stops driving the compressor 31, the decompression expansion valve 33, the blower 36, and the heating circulation pump 37 and stops the heating operation by the heat pump cycle (step S10). .

  Here, the boiling stop condition is that the hot water storage temperature sensor 15 at the bottom of the hot water storage tank 6 is 50 ° C. or higher, the remaining time of the predicted boiling time is 0, or the end time of a specific time zone. One of the conditions is that the start time of the midnight time zone is satisfied.

  Here, when hot water is supplied at an arbitrary hot water supply temperature, the rate of decrease in the amount of hot water stored in the hot water storage tank 6 is faster when the hot water storage temperature is lower than when the hot water storage temperature is high. Since the boiling start is started in a state where the amount of hot water discharged from the hot water storage tank 6 is small, when the hot water storage temperature is low, the start timing of the boiling increase is advanced, and the possibility of occurrence of hot water can be reduced. .

  On the other hand, when the hot water storage temperature is high, the rate of decrease in the hot water storage rate is slow even with the same hot water supply amount. Therefore, the amount of heat released from the hot water storage tank 6 is prevented while the hot water start is delayed by delaying the start timing of boiling. To improve the overall operation efficiency.

  Further, since the boiling start condition is changed based on the hot water storage temperature detected by the uppermost hot water storage temperature sensor 15 in the daytime period, if the hot water storage temperature is high immediately after the completion of boiling, the boiling start timing is delayed. When the hot water storage temperature is low due to the completion of boiling, or when the temperature of the hot water is low due to reheating of the bath, etc. It is possible to increase boiling in a situation where it is easy to perform, and to improve overall operation efficiency.

  After stopping the boiling increase operation, the process returns to the step S3, and the hot water storage temperature detected by the hot water storage temperature sensor 15 located at the uppermost portion of the hot water storage tank 6 is confirmed again, and the hot water storage temperature is set to a predetermined value (here, If the temperature is lower than the predetermined value, the process proceeds to step S4, where the condition for starting the boiling increase operation is set as a predetermined boiling start condition 1 and is equal to or higher than the predetermined value. Advances to step S5, and the condition for starting the boiling increase operation is set as a predetermined boiling start condition 2.

  Subsequently, in step S6, it is confirmed whether or not there is a remaining time of the predicted boiling time. If there is a predicted boiling time, the process proceeds to step S7 with Yes, and the above operation is performed. When the remaining time is 0, the process proceeds to step S11 with No, and the condition for starting the boiling increase operation is set as the boiling start condition 3.

  Here, the boiling start condition 3 is a condition for securing a minimum amount of stored hot water in order to prevent the hot water in the hot water storage tank 6 from becoming empty. Here, the hot water storage temperature sensor 15 at the top of the hot water storage tank 6 is used. The temperature is lower than 50 ° C. as a condition for starting the boiling operation, and is a condition that makes it difficult to start boiling than the above-described boiling start conditions 1 and 2.

  After the boiling increase start condition 3 is set, when the boiling increase start condition 3 is satisfied (Yes in step S7), the hot water storage control means 30 outputs an instruction to start the boiling increase operation to the heating control means 42, The heating control means 42 drives the compressor 31, the decompression expansion valve 33, the blower 36, and the heating circulation pump 37 so that the temperature detected by the boiling temperature sensor 40 coincides with the boiling target temperature, and is heated by the heat pump cycle. An additional operation is started (step S8).

  Then, the hot water storage control unit 30 monitors whether or not the boiling stop condition is satisfied by the boiling operation (step S9), and when the boiling stop condition is satisfied, the hot water storage control unit 30 issues an instruction to stop the boiling operation. The heating control means 42 outputs to the heating control means 42, and the heating control means 42 stops driving the compressor 31, the decompression expansion valve 33, the blower 36, and the heating circulation pump 37 and stops the heating operation by the heat pump cycle (step S10). .

  Here, when the boiling start condition 3 is set as the boiling stop condition, the fact that the second hot water storage temperature sensor 15 from the top of the hot water storage tank 6 is 50 ° C. or higher is used as the boiling stop condition. We try to secure the minimum amount of hot water storage just to avoid the situation where can not be used.

  As described above, the predetermined boiling start condition is changed according to the hot water storage temperature, and when the hot water storage temperature is low, the start timing of the boiling increase is changed so that the possibility of occurrence of hot water shortage can be reduced. At the same time, when the hot water storage temperature is high, it is difficult to start the boiling increase operation, and the overall operation efficiency can be improved without performing the unnecessary boiling increase operation.

  In this embodiment, the hot water storage temperature is changed to the boiling increase start condition at which the hot water storage temperature is 75 ° C. or less and the boiling operation is easy to start. However, the present invention is not limited to this. When the hot water storage temperature is 85 ° C. or higher, the boiling start condition 4 (for example, the third from the top of the hot water storage tank 6 is less likely to start boiling than the boiling start condition 2 and more likely to start boiling than the boiling start condition 3). It is also possible to select that the hot water storage temperature sensor 15 is below 45.degree.

<Another embodiment>
Next, another embodiment of the present invention will be described with reference to the drawings. In the previous embodiment, the boiling start condition is changed according to the hot water storage temperature. In this embodiment, the boiling start condition is changed according to the boiling target temperature. Since the points are different, the same components as those of the previous embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  Here, the hot water storage control means 30 determines the boiling target temperature in the boiling operation as described above, and the hot water storage control means 30 functions as a boiling target temperature recognition means for recognizing the boiling target temperature. Is.

<Boiling operation>
Next, the heating operation of this embodiment will be described based on the flowchart of FIG.
When the end time of the midnight time zone, which is the start time of a specific time zone, is reached, the hot water storage control means 30 confirms the current hot water storage amount detected by the hot water temperature sensor 15 (step S12), and according to the hot water storage amount and the hot water supply load. Subtracted from the target hot water storage volume calculated in this step to calculate the shortage, and from this shortage, the boiling target temperature, the feed water temperature, and the heating capacity, the time required to boil the shortage in the daytime period (Predicted boiling increase time) is calculated (step S13).

  In subsequent step S14, the hot water storage control means 30 confirms the boiling target temperature determined in the boiling operation, and determines whether or not the boiling target temperature is lower than a predetermined value (here, 75 ° C.). If it is lower than the predetermined value, the process proceeds to step S15, where the condition for starting the boiling increase operation is set to a predetermined boiling increase start condition 1, and if it is equal to or greater than the predetermined value, the process proceeds to step S16 to perform the boiling increase operation. The condition for starting is set as a predetermined boiling start condition 2.

  Here, the boiling start condition 1 is that the fourth hot water storage temperature sensor 15 below the hot water storage tank 6 is below 50 ° C., and the boiling start condition 2 is that of the hot water storage tank 6. The condition that the third hot water storage temperature sensor 15 from the top falls below 50 ° C. is used as a condition for starting the heating operation, and the boiling starting condition 1 is started when the amount of hot water discharged from the hot water storage tank 6 is smaller. Therefore, it is set as a condition that it is easier to start boiling up than in boiling starting condition 2.

  Next, in step S17, it is confirmed whether or not there is a predicted boiling-up time. If there is a predicted boiling-up time, the process proceeds to step S18 with Yes, and the boiling start condition defined in step S15 or step S16 is set. Monitor whether it is true.

  When the amount of heat in the hot water storage tank 6 is consumed by hot water supply or bath operation and the boiling start condition is satisfied (Yes in step S18), the hot water storage control means 30 outputs an instruction to start the boiling increase operation to the heating control means 42. Then, the heating control means 42 drives the compressor 31, the decompression expansion valve 33, the blower 36, and the heating circulation pump 37 so that the temperature detected by the boiling temperature sensor 40 coincides with the boiling target temperature, and the heat pump cycle. The boiling increase operation by is started (step S19). At this time, the hot water storage control means 30 measures the operating time of the boiling increase operation and subtracts it from the predicted boiling increase time.

  Then, the hot water storage control unit 30 monitors whether or not the boiling stop condition is satisfied by the boiling operation (step S20). When the boiling stop condition is satisfied, the hot water control unit 30 issues an instruction to stop the boiling operation. Output to the heating control means 42, the heating control means 42 stops driving the compressor 31, the decompression expansion valve 33, the blower 36 and the heating circulation pump 37 to stop the heating operation in the heat pump cycle (step S21). ).

  Here, the boiling stop condition is that the hot water storage temperature sensor 15 at the bottom of the hot water storage tank 6 is 50 ° C. or higher, the remaining time of the predicted boiling time is 0, or the end time of a specific time zone. One of the conditions is that the start time of the midnight time zone is satisfied.

  Here, when hot water is supplied at an arbitrary hot water supply temperature, the rate of decrease in the amount of hot water stored in the hot water storage tank 6 is faster when the hot water storage temperature is lower than when the hot water storage temperature is high. Since boiling is started when the amount of hot water discharged from the hot water storage tank 6 is small, when the boiling target temperature is low, the timing of starting boiling increases and the possibility of occurrence of hot water is reduced. Can do.

  On the other hand, when the boiling target temperature is high, the rate of decrease in the amount of hot water is slow even with the same amount of hot water supply. It is possible to improve the overall operation efficiency by reducing the heat radiation amount.

  After stopping the boiling increase operation, the process returns to step S17 to check whether or not there is a remaining time for the predicted boiling increase time. If there is a predicted boiling increase time, the process proceeds to step S18 with Yes, When the operation is performed and the remaining time of the predicted boiling time is zero, the process proceeds to step S22 with No, and the condition for starting the boiling increase operation is set as the boiling start condition 3.

  Here, the boiling start condition 3 is a condition for securing a minimum amount of stored hot water in order to prevent the hot water in the hot water storage tank 6 from becoming empty. Here, the hot water storage temperature sensor 15 at the top of the hot water storage tank 6 is used. The temperature is lower than 50 ° C. as a condition for starting the boiling operation, and is a condition that makes it difficult to start boiling than the above-described boiling start conditions 1 and 2.

  After the boiling increase start condition 3 is set, if the boiling increase start condition 3 is satisfied (Yes in step S18), the hot water storage control means 30 outputs an instruction to start the boiling increase operation to the heating control means 42, The heating control means 42 drives the compressor 31, the decompression expansion valve 33, the blower 36, and the heating circulation pump 37 so that the temperature detected by the boiling temperature sensor 40 coincides with the boiling target temperature, and is heated by the heat pump cycle. The additional operation is started (step S19).

  Then, the hot water storage control unit 30 monitors whether or not the boiling stop condition is satisfied by the boiling operation (step S20). When the boiling stop condition is satisfied, the hot water control unit 30 issues an instruction to stop the boiling operation. Output to the heating control means 42, the heating control means 42 stops driving the compressor 31, the decompression expansion valve 33, the blower 36, and the heating circulation pump 37 to stop the heating operation by the heat pump cycle (step S 21). .

  Here, when the boiling start condition 3 is set as the boiling stop condition, the fact that the second hot water storage temperature sensor 15 from the top of the hot water storage tank 6 is 50 ° C. or higher is used as the boiling stop condition. We try to secure the minimum amount of hot water storage just to avoid the situation where can not be used.

  As described above, the predetermined boiling start condition is changed according to the boiling target temperature, and when the boiling target temperature is low, the timing for starting boiling is changed so that hot water can run out. When the boiling target temperature is high, it is difficult to start the boiling increase operation, and the overall operation efficiency can be improved without performing the unnecessary boiling increase operation.

  In the two embodiments described above, the boiling start condition is not limited to the above example. For example, among the plurality of hot water storage temperature sensors 15, the hot water storage temperature sensor 15 (here, the hot water storage tank 6). The condition is that the third hot water storage temperature sensor 15) from the top is equal to or lower than the predetermined temperature. If the feed water temperature or the outside air temperature is lower than the predetermined value, the predetermined temperature is 55 ° C., and the hot water storage temperature or the boiling target temperature is predetermined. If the temperature is higher than the specified value, the predetermined temperature is set to 50 ° C. If the hot water storage temperature or the boiling target temperature is lower than the predetermined value, the temperature starts to increase in a direction that makes it easy to start boiling if the temperature is higher than the predetermined temperature. The conditions may be changed.

2 Heat pump unit (heat pump heating means)
6 Hot water storage tank 7 Water supply pipe 8 Hot water discharge pipe 14 Water supply temperature sensor 15 Hot water storage temperature sensor 29 Heating circulation circuit 30 Hot water storage control means (control means, boiling temperature recognition means)

Claims (4)

A hot water storage tank for storing hot water, a water supply pipe connected to the lower part of the hot water storage tank, a hot water pipe connected to the upper part of the hot water storage tank, and a heating circuit for circulating hot water from the lower part of the hot water storage tank to the upper part of the hot water storage tank; A heat pump type heating means that is provided in the middle of the heating circulation circuit and that heats the heated hot water so as to match the boiling target temperature, and a hot water storage temperature sensor that is provided in the hot water storage tank and detects the hot water storage temperature. When the hot water storage temperature sensor detects that the hot water storage amount in the hot water storage tank satisfies a predetermined heating start condition in a specific time zone, the heating pump heating means is operated to increase the hot water storage amount. Control means for performing a plurality of hot water storage temperature sensors at the start of the specific time zone or at the end of the boiling increase operation. The heat pump hot water storage type water heater, characterized in that the stored hot water temperature sensor located Chi topped so as to change said predetermined reheating start condition in accordance with the hot-water storage temperature detected. A hot water storage tank for storing hot water, a water supply pipe connected to the lower part of the hot water storage tank, a hot water pipe connected to the upper part of the hot water storage tank, and a heating circuit for circulating hot water from the lower part of the hot water storage tank to the upper part of the hot water storage tank; A heat pump type heating means that is provided in the middle of the heating circulation circuit and that heats the heated hot water so as to match the boiling target temperature, and a hot water storage temperature sensor that is provided in the hot water storage tank and detects the hot water storage temperature. A heating target temperature recognizing means for recognizing the boiling target temperature, and when the hot water storage temperature sensor detects that the amount of hot water stored in the hot water storage tank satisfies a predetermined boiling start condition in a specific time zone, the heat pump and control means for performing additional boiling operation to increase the amount of hot water storage by operating the equation heating means, the control means, the water heating target temperature The heat pump hot water storage type hot water supply apparatus is characterized in that so as to change said predetermined reheating start condition in accordance with the boiling target temperature identification means recognizes.   When the hot water storage temperature or the boiling target temperature is equal to or higher than a predetermined value, a heating start condition is that a specific hot water temperature sensor of the plurality of hot water temperature sensors is equal to or lower than a predetermined temperature, and the hot water storage temperature or the When the boiling target temperature is lower than the predetermined value, it starts to increase that the hot water storage temperature sensor provided at a position lower than the specific hot water storage temperature sensor when the heating target temperature is equal to or higher than the predetermined value is equal to or lower than the predetermined temperature. The heat pump hot water storage type hot water supply apparatus according to claim 1 or 2, wherein the predetermined boiling increase start condition is changed according to the hot water storage temperature or the boiling target temperature so as to satisfy the conditions.   When the hot water storage temperature or the boiling target temperature is equal to or higher than a predetermined value, a heating start condition is that a specific hot water temperature sensor of the plurality of hot water temperature sensors is equal to or lower than a predetermined temperature, and the hot water storage temperature or the When the boiling target temperature is lower than the predetermined value, the heating start condition is that the specific hot water storage temperature sensor is equal to or lower than a predetermined temperature lower than the predetermined temperature when the specific hot water temperature sensor is equal to or higher than the predetermined value. The heat pump hot water storage type hot water supply apparatus according to claim 1 or 2, wherein the predetermined boiling increase start condition is changed according to the hot water storage temperature or the boiling target temperature.

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