JP5745779B2 - Hot water system - Google Patents

Description

  The present invention relates to a hot water supply system including a hot water storage tank that enables immediate hot water supply.

  Conventionally, there has been a hot water supply system equipped with a hot water storage tank and an electric heat pump hot water supply means. In such a hot water supply system, hot water heated by using inexpensive nighttime electric power is stored in a hot water storage tank by a heat pump hot water supply means, and hot water can be supplied from the hot water storage tank to a hot water supply channel to which a hot water discharge terminal is attached.

  However, since the heating capacity of the heat pump hot water supply means is determined assuming a low hot water supply load state at night, the heating capacity is often set low. Therefore, when a large amount of hot water is consumed in the hot water storage tank when the hot water supply load is high, there is a risk that the hot water supply capacity is insufficient and so-called “hot water out” occurs.

  In view of this, a hot water supply system has been proposed in which auxiliary hot water supply means using gas or oil is connected in parallel to the hot water storage tank in addition to the electric heat pump hot water supply means connected to the hot water storage tank (see, for example, Patent Document 1). . As described above, a hot water supply system is known in which the auxiliary hot water supply means and the heat pump hot water supply means are provided in parallel to the hot water storage tank so as to compensate for the lack of heating capacity of the heat pump hot water supply means.

  Further, in the hot water supply system of Patent Document 1, the following control is executed in order to improve the overall energy efficiency of the entire system.

  That is, (a) A predetermined amount of hot water is heated by the heat pump hot water supply means and stored in the hot water storage tank during a first time period mainly including nighttime when a low hot water supply load state is reached within one day. (B) Hot water supply to the hot water supply load only from the hot water storage tank when the hot water storage amount of the hot water storage tank is greater than or equal to a predetermined first hot water storage amount in a second time zone other than the first time zone within one day To do. (C) During the second time period, when the amount of hot water stored in the hot water storage tank falls below the first amount of hot water stored, hot water heating by the heat pump hot water supply means is added. (D) If the amount of hot water stored in the hot water storage tank falls below a predetermined second hot water storage amount that is less than the first hot water storage amount during the second time period, hot water supply by the auxiliary hot water supply means is further added.

  That is, hot water for supplying hot water supply in the second time zone (for example, 9:00 to 21:00) to the hot water storage tank in the first time zone (for example, 22:00 to 8:00) where inexpensive nighttime electricity can be used. Because the hot water is stored, the heat pump hot water supply means with a high coefficient of performance can be operated with high efficiency and at low cost, and the coefficient of performance is high according to the amount of hot water stored in the hot water tank during the second time period, mainly during the daytime. Since the capability of hot water supply from the heat pump hot water supply means to the auxiliary hot water supply means is added in order, high-efficiency hot water supply is possible without causing “hot water out” even at high hot water supply loads.

JP 2006-349201 A

  However, in the control described in Patent Document 1 described above, the hot water supply timing by the heat pump hot water supply means and the hot water supply timing by the auxiliary hot water supply means are determined in relation to the time zone and a predetermined remaining hot water amount (hot water storage amount). For this reason, it is difficult to respond flexibly to sudden changes in the hot water supply load.

  Further, for example, the first remaining hot water amount (hot water storage amount) is set to 100% in the first time zone and 80% in the second time zone, and the second remaining hot water amount (hot water storage amount) smaller than the first remaining hot water amount is set to the first. When set to 0% in the time zone and 50% in the second time zone, as shown in FIG. 5, the heat pump hot water supply means always performs hot water storage operation when the remaining hot water amount is less than the first remaining hot water amount. The remaining hot water amount has already increased (85%) at the time of entering the first time zone from the second time zone (22:00). Therefore, if there is no hot water supply load in the first time zone, only heat is dissipated, and the energy efficiency of the entire hot water supply system is reduced.

  Moreover, since there is a sufficient amount of remaining hot water at the time of entering the first time zone, as shown in the figure, the heat pump hot water supply means only stores 15% of hot water during the first time zone, and the nighttime electric power that is cheaper is available. Since it cannot be used effectively, the cost merit is small, and a sufficient reduction in operating cost cannot be expected. Further, as shown in FIG. 5, in the control described in Patent Document 1, depending on the setting of the second hot water storage amount in the second time zone, the auxiliary hot water supply means can be frequently driven by gas fired or oiled. Therefore, it cannot be said that it is necessarily advantageous in terms of running cost when considering the total for one day.

  In order to solve the above-described problem, the present invention controls the on / off state of the first heat source and the second heat source so that the set remaining hot water amount is set at times during execution of the remaining hot water amount control. The purpose is to provide a hot water supply system.

(1) A hot water supply system according to the present invention is connected to a hot water storage tank, a hot water terminal, and a hot water flow path connected to the hot water storage tank, and a hot water storage tank connected to the hot water storage tank via the main circulation flow path for hot water storage. A first heat source, a second heat source having relatively higher heating capacity and heating cost than the first heat source, and connected in communication with the hot water storage tank via an auxiliary circulation channel for hot water storage; and the hot water storage A sensor for continuously detecting the amount of hot water in the tank, and control means for controlling the amount of hot water in the hot water storage tank in order to perform stable hot water supply to the hot water supply flow path, A predetermined amount of hot water heated by the first heat source is stored in the hot water storage tank in advance, and then the first heat source and the heat source are set so as to have a set remaining hot water amount set during execution of the remaining hot water amount control. A hot water supply system for controlling the on / off state of the second heat source, While the first heat source is an electrically driven heat pump, the second heat source is a water heater using fossil fuel, and the control means is a first time during which nighttime power is applied for one day as an operation time. And the first set remaining hot water amount that is also used as a threshold value for the remaining hot water amount control is stored, and the first set remaining hot water amount is: If the amount of hot water in the hot water storage tank is less than the first set remaining hot water amount, the first heat source is operated, and if the amount exceeds the first set remaining hot water amount, the threshold value for stopping the operation of the first heat source. At least during the first time period, the first set remaining hot water amount is set to a predetermined amount in advance based on the capacity of the hot water storage tank, and the first heat source is preferentially driven, while the second In the time zone, keep the amount of remaining hot water sufficient to cover the amount of the first set remaining hot water. Are those gradually reduced per unit time period, wherein the control means, said first set remaining hot water with relatively the remaining hot water are fewer second setting remaining hot water is further stores the second If the amount of hot water in the hot water storage tank is less than the second set remaining hot water amount, the second heat source is operated, and if the set remaining hot water amount exceeds the second set remaining hot water amount, the second heat source The threshold value for stopping operation, and the control means gradually approaches the first set remaining hot water amount and the second set remaining hot water amount in the second time zone, and thereafter maintains a predetermined amount difference. It was decided to perform control .

( 2 ) The present invention provides the hot water supply system according to (1 ) , wherein a plurality of the first heat sources are arranged in parallel to the hot water storage tank, and the control means stores the amount of hot water stored in the hot water storage tank. The number of first heat sources to be driven is determined according to the degree that the amount is less than the first set remaining hot water amount.

( 3 ) According to the present invention, in the hot water supply system of ( 2 ), a plurality of the second heat sources are arranged in parallel to the hot water storage tank, and the control means has a hot water storage amount of the hot water storage tank. Whether or not to drive the second heat source is determined according to the degree below the second set remaining hot water amount, and the number of second heat sources to be driven is determined.

According to the present invention, since the on / off state of the two heat sources is controlled according to the hot water supply load, sufficient hot water can be supplied without causing a so-called “hot water outage”, and the amount of hot water supplied can be covered. It is possible to reduce the total operation time of the two heat sources in a day as much as possible, thereby saving energy and reducing CO ₂ . In addition, for example, all the hot water made on the previous day can be used up on the day, and it is possible to boil up the shortage with the first heat source or the second heat source on the day, so a money-saving system with extremely low running costs be able to.

It is a typical whole lineblock diagram of a hot-water supply system concerning one embodiment of the present invention. It is explanatory drawing which shows the basic example of the flow of the hot water supply control by the hot water supply system. It is explanatory drawing which shows the relationship between the operation | movement of the heat source by the hot-water supply system, and the amount of hot water storage. It is explanatory drawing which shows an example of the flow of the hot water supply control by the hot water supply system. It is explanatory drawing which shows the relationship between the operation | movement of the heat source by the conventional hot-water supply system, and the amount of hot water storage.

  An embodiment of a hot water supply system according to the present invention will be described with reference to the drawings. Hereinafter, hot water having a predetermined temperature or more suitable for hot water supply is referred to as “hot water” or “warm water”, and other than that, it includes “hot water” including water and slightly hot water. Further, the remaining hot water amount in the hot water tank 3 is expressed as a ratio (%) to the total capacity of the hot water tank 3.

  As shown in FIG. 1, a hot water supply system according to the present embodiment includes an electrically driven heat pump unit 1 as a first heat source, and a water heater 2 as a second heat source having a larger heating capacity than the heat pump unit 1. A cylindrical hot water storage tank 3 and a control unit 4 as control means for performing hot water supply control are provided. The water heater 2 as the second heat source uses fossil fuels such as oil and gas, so the heating capacity is larger and more stable than the heat pump unit 1, but the fuel cost is higher than the electricity cost. The cost, that is, the running cost is also larger than that of the heat pump unit 1.

  The hot water storage tank 3 is formed in a closed circulation type and communicates with the raw water supply source via the raw water supply flow path 5 and also communicates with the hot water supply flow path 6 to which a hot water discharge terminal 61 such as a faucet or a shower head is attached. doing. The heat pump unit 1 includes a circulation pump 11, communicates with the hot water storage tank 3 through the hot water storage main circulation flow path 7, and passes through the hot water storage tank 3 to the raw water supply flow path 5 and the hot water supply flow path 6, respectively. Communicate. The hot water machine 2 communicates with the hot water storage tank 3 via the hot water storage auxiliary circulation flow path 8, and communicates with the raw water supply flow path 5 and the hot water supply flow path 6 via the hot water storage tank 3, respectively. A hot water machine circulation pump 81 is disposed in the middle of the hot water storage auxiliary circulation channel 8. Although not shown, various valve mechanisms and the like according to need are appropriately disposed in each of the flow paths 5, 6 and 7.

  That is, at the ceiling of the hot water storage tank 3, the base end of the hot water supply passage 6 in which a plurality of hot water discharge terminals 61 are attached and one end of the main circulation passage 7 for hot water storage for supplying hot water from the heat pump unit 1. Similarly, one end of an auxiliary circulation channel 8 for hot water storage for supplying hot water from the hot water machine 2 is connected in communication.

  On the other hand, at the bottom of the hot water tank 3, the distal end of the raw water supply passage 5 whose base end communicates with the water source, the other end of the main circulation passage 7 for hot water storage for supplying water to the heat pump unit 1, and the water heater The other end of the hot water storage auxiliary circulation flow path 8 for supplying water to 2 and the other end of the water supply pipe 63 communicatively connected to the mixing valve 62 provided at one end in the middle of the hot water supply flow path 6 are connected. Thus, since the hot water supply channel 6 can be supplied with water via the mixing valve 62, the hot water supply temperature can be adjusted by adjusting the amount of water supplied from the water source by adjusting the opening of the mixing valve 62.

  In the figure, reference numeral 31 denotes an upper inlet / outlet hot water inlet serving as a communication part between the hot water storage tank 3 and the hot water supply flow path 6, and reference numeral 32 denotes a lower water supply inlet serving as a communication part between the hot water storage tank 3 and the raw water supply flow path 5. Yes. Reference numerals 33 and 34 denote a lower connection port and an upper connection port that serve as a communication portion between the hot water storage tank 3 and the hot water storage main circulation flow path 7, and reference numerals 35 and 36 denote the hot water storage tank 3 and the hot water storage auxiliary circulation flow path 8. Reference numeral 37 denotes a communication port between the hot water storage tank 3 and the water supply pipe 63.

  As shown in the figure, in this embodiment, in order to facilitate understanding, the raw water supply flow path 5, the hot water supply flow path 6, the hot water storage main circulation flow path 7, the hot water storage auxiliary circulation flow path 8, and the water supply pipe 63 are independent of each other. However, for example, the water supply pipe 63 is configured to be branched from the raw water supply flow path 5 or the hot water storage main circulation flow path 7 and the hot water supply flow path 6 are connected. ) Or the like. That is, if the portion indicated by reference numeral 30 in FIG. 1 is a hot water tank unit, the design of piping and the like in the hot water tank unit 30 can be changed as appropriate.

  Moreover, in the hot water tank 3, as shown in the drawing, a plurality of temperature sensors 9 (9a to 9h) are arranged in series at predetermined intervals in the height direction, and the temperature detected by the temperature sensor 9 is used. The remaining amount in the hot water tank 3 can be calculated.

  That is, hot water is supplied from the hot water storage tank 3 to the hot water supply passage 6 from the upper inlet / outlet hot water inlet 31, but water corresponding to the hot water supplied is sequentially supplied from the lower inlet 32. Accordingly, the temperature in the hot water storage tank 3 decreases in order from the lowest side to the upper level. As a result, the hot water in the hot water tank 3 is stored in different layer states with different hot water temperatures.

  Therefore, the remaining hot water amount in the hot water tank 3 can be known from the detected temperatures of the temperature sensors 9 (9a to 9h) provided at different heights at predetermined intervals. For example, in the example shown in FIG. 1, it can be seen that about 30% (shaded portion) of the hot water at a temperature higher than the temperature that can be used for hot water supply remains in the upper part of the hot water tank 3.

  In particular, in the present embodiment, eight temperature sensors 9 are provided, and the amount of remaining hot water can be detected almost continuously. That is, it is possible to detect the amount of remaining hot water almost continuously by calculation from the detected temperature of each hot water layer by each temperature sensor 9. Theoretically, as the number of temperature sensors 9 increases, the detection accuracy of the remaining hot water amount increases. However, considering the cost effectiveness, the interval between the temperature sensors 9, 9 is set to an appropriate value of, for example, about 200 mm. The number of temperature sensors 9 can be determined as appropriate according to the size of the hot water tank 3. In addition, it is preferable to provide at least 5 or more temperature sensors 9, and usually 5 to 10 are provided.

The heat pump unit 1 is a main heat source of the hot water supply system, and although not shown, a compressor for compressing the refrigerant to a high temperature, a hot water storage heat exchanger, a heat pump heat exchanger, an accumulator, and the like are provided. Has been. And the hot water taken from the lower connection port 33 of the hot water tank 3 is heated by the heat of the refrigerant discharged from the compressor. The heat pump unit 1 according to the present embodiment heats water with the heat of the air taken out through a natural refrigerant such as CO ₂ (carbon dioxide). The heated hot water is supplied to the hot water storage tank 3 from the upper connection port 34.

  In this hot water supply system mainly using the heat pump unit 1 as described above, since only the heat of the atmosphere is moved, more heat energy than the input energy can be used, and the running cost is excellent. That is, the heat pump unit 1 is more efficient than a heating device such as a boiler that burns and heats fossil fuel and has a low environmental load. Furthermore, it is possible to reduce running costs by performing circulating hot water supply at a temperature lower than the hot water storage temperature using the heat stored by performing high-temperature hot water storage using inexpensive nighttime electric power.

  On the other hand, the hot water machine 2 functions as an auxiliary hot water supply means for the heat pump unit 1, and heats hot water taken from the lower connection port 35 of the hot water tank 3 and supplies the hot water to the hot water tank 3 from the upper connection port 36. I am doing so. In this embodiment, it is comprised with the gas-fired vacuum type boiler. For example, a gas-fired vacuum boiler is provided with a furnace that heats the heat transfer water with a flame of a gas burner in the lower part of the can body, a U-shaped heat transfer tube in the decompressed air in the upper part of the can body, The heat transfer water sealed in is heated with a flame of a gas burner, the heat transfer tube in the decompressed air above is heated, and the water flowing in the heat transfer tube is heated. In this embodiment, the can output is, for example, about 100 kW.

  The control unit 4 also functions as a remaining hot water amount calculation means, and can be time-measured with a CPU, a control program, a computer having a storage means in which a set remaining hot water amount table, which will be described later, past operation history data, and the like are stored. The configuration includes a timer. The storage means is not particularly limited. For example, an EPROM or a working RAM may be provided.

  Moreover, the control part 4 is electrically connected with the temperature sensors 9a-9h provided in the hot water storage tank 3, and the detection signal output from each temperature sensor 9 is input into the said control part 4 so that it may show in figure. Is done. The control unit 4 is also electrically connected to the heat pump unit 1, the circulation pump 11, the hot water machine 2, and the hot water machine circulation pump 81.

  With such a configuration, the control unit 4 calculates the set remaining hot water amount necessary at that time based on the set remaining hot water amount table, the past operation history data, and the detection signal of the temperature sensor 9 so as to be the set remaining hot water amount. The operation of the heat pump unit 1 and the hot water machine 2, the operation of the circulation pump 11 and the circulation pump 81 for the hot water machine, and the drive control of various solenoid valves are performed to control the remaining hot water amount.

  That is, as shown in FIG. 2, when the operation of the hot water supply system is started, the control unit 4 first drives the heat pump unit 1 (first heat source) to supply the heated hot water to the hot water storage tank 3 in advance. A certain amount (for example, a preset amount between 80 and 100% of the hot water tank 3) is stored (step S1).

  Next, the control unit 4 determines the set remaining hot water amount (step S2). For example, an EPROM or the like stores a set remaining hot water amount table in which a set remaining hot water amount corresponding to the transition of the hot water supply amount corresponding to the environment such as a facility where the present hot water supply system is introduced is allocated for each unit time of the day, The CPU reads this and determines the set remaining hot water amount at that time.

  Next, the control unit 4 calculates the current remaining hot water amount based on the detection signal of the temperature sensor 9, and determines whether or not the current remaining hot water amount is smaller than the set remaining hot water amount (step S3). The control unit 4 supplies hot water from only the hot water storage tank 3 to the hot water supply passage 6 except when the current remaining hot water amount is smaller than the set remaining hot water amount.

  If it is determined that the current remaining hot water amount is smaller than the set remaining hot water amount, the control unit 4 supplies hot water to the hot water storage tank 3 based on the difference between the current remaining hot water amount and the set remaining hot water amount. 1 heat source), that is, whether or not the operation condition of the heat pump unit 1 (first heat source) is met (step S4).

  When it is determined that hot water is supplied by the operation of the heat pump unit 1 (step S4: YES), the control unit 4 drives the heat pump unit 1 (step S5) to supply hot water to the hot water storage tank 3 and return the process to step S2.

  On the other hand, when it is determined that hot water is not supplied by the operation of the heat pump unit 1 (step S4: NO), the control unit 4 does not supply hot water to the hot water storage tank 3 based on the difference between the current remaining hot water amount and the set remaining hot water amount. It is determined whether or not the operation is performed by the water heater 2 (second heat source), that is, whether or not the operation conditions of the water heater 2 (second heat source) are met (step S6).

  When it determines with supplying hot water by the driving | operation of the hot water machine 2 (step S6: YES), the control part 4 drives the hot water machine 2 (step S7), while supplying hot water to the hot water storage tank 3, and returns a process to step S2. Moreover, also when it determines with not performing hot water supply by driving | operation of the hot water machine 2 (step S6: NO), the control part 4 returns a process to step S2.

  As described above, the control unit 4 of the hot water supply system according to the present embodiment stores a predetermined amount of hot water heated by the heat pump unit 1 in the hot water storage tank 3 in advance, and thereafter, is set at times during execution of the remaining hot water amount control. The on / off state of the heat pump unit 1 and the hot water machine 2 is controlled so that the set remaining hot water amount is obtained.

  In addition, as the remaining hot water amount control by the control unit 4, the control unit 4 divides the operation time for executing the remaining hot water amount control into unit time zones, and sets the remaining hot water amount for each past unit time zone as past operation history data. It is possible to cover the required hot water supply amount to the hot water supply flow path 6 which is set based on the actual hot water supply performance and is predicted at times during execution of the remaining hot water amount control. Here, the past hot water supply performance for each unit time zone means that the time zone from midnight to 23:00 is divided into unit time (1 hour) in one day (24 hours), and each time zone (for example, The past average hot water supply amount (average amount of hot water used) at 0:00 to 1 o'clock. In addition, it is preferable to classify and manage the past average hot water supply amount according to day of the week (category such as a holiday, Saturday, Sunday, weekday).

  FIG. 3 shows the relationship between the operation of each heat source (heat pump unit 1 and hot water machine 2) and the amount of hot water stored in the hot water tank 3 when such remaining hot water amount control is performed. In the following, the relationship between the operation of each heat source (heat pump unit 1 and water heater 2) by the conventional system described in “Problems to be solved by the invention” and the amount of hot water stored in the hot water tank (FIG. 5) is compared. As an example, description will be given while comparing the two as appropriate.

  As shown in FIG. 3, the first time zone (22:00 to 8:00) in which nighttime power is applied and the second in which daytime power is applied during one day (24 hours) as the operation time of the hot water supply system. It is divided into the time zone (from 8:00 to 22:00). Then, the set remaining hot water amount serving as a threshold value for the remaining hot water amount control is set to a first set remaining hot water amount having a relatively large remaining hot water amount and a second set remaining hot water amount having a relatively small remaining hot water amount.

  Here, as shown in the drawing, the set remaining hot water amount in the first time zone is set in advance to a constant amount (for example, 100%) based on the capacity of the hot water storage tank 3, and the remaining hot water amount control is performed in the second time zone. The amount of remaining hot water is set variably so as to be able to secure the amount of hot water used to be predicted at times during execution. In this embodiment, from 8 o'clock to 16 o'clock, it is gradually decreased by 10% for each unit time zone, and after that, the setting of 20% is maintained.

  Moreover, the control part 4 is made to drive the heat pump unit 1 preferentially in the 1st time slot | zone. That is, in the first time zone, the heat pump unit 1 is operated until the hot water tank 3 is full, so that cheap nighttime electric power is effectively used.

  Further, the second set remaining hot water amount is set to 10% in the first time zone, while the second time zone is variable as in the first set remaining hot water amount. In this embodiment, it is set to 50% at 8 o'clock when entering the first time zone, and thereafter it is gradually reduced by 5% per unit time zone until 16:00, and thereafter 10% which is the same as the first time zone. The setting is maintained.

  Such control of the amount of remaining hot water is executed in the process flow shown in FIG. That is, when the operation of the hot water supply system is started, the controller 4 first drives the heat pump unit 1 (first heat source) to store the heated hot water in the hot water storage tank 3 at 100% (step S11). ).

  Next, the control unit 4 determines the first and second set remaining hot water amounts (step S12). Here, as described above, in the first time zone, the first set remaining hot water amount is set to 100% and the second set remaining hot water amount is set to 10%.

  Further, in the second time zone, the first set remaining hot water amount is gradually increased from 100% to 10 per unit time zone based on the past hot water supply performance for each unit time zone as past operation history data stored in the EPROM. It is set to decrease by% (see FIG. 3). On the other hand, the second set remaining hot water amount is set to be gradually decreased from 50% by 5% for each unit time zone (see FIG. 3).

  Next, the control unit 4 determines whether or not the current remaining hot water amount is smaller than the first set remaining hot water amount and larger than the second set remaining hot water amount (step S13). When the current remaining hot water amount is equal to or greater than the first set remaining hot water amount, the control unit 4 supplies hot water from only the hot water storage tank 3 to the hot water supply passage 6.

  If the first set remaining amount> the current remaining hot water amount> the second set remaining amount is satisfied (step S13: YES), the heat pump unit 1 is driven to operate (step S14), and hot water is supplied to the hot water tank 3. At the same time, the process returns to step S11.

  On the other hand, if the first set remaining hot water amount> the current remaining hot water amount> the second set remaining hot water amount is not satisfied in step S13 (step S13: NO), the control unit 4 determines whether the current remaining hot water amount is smaller than the second set remaining hot water amount. It is determined whether or not (step S15).

  If the second set remaining amount> the current remaining hot water amount (step S13: YES), the water heater 2 is operated to supply hot water to the hot water tank 3 (step S16), and the second set remaining amount> current remaining hot water amount. If not (step S13: NO), the process returns to step S11.

  Thus, in the remaining hot water amount control in the hot water supply system according to the present embodiment, when the remaining hot water amount in the hot water storage tank 3 is equal to or larger than the first set remaining hot water amount (or exceeds the first set remaining hot water amount), hot water is supplied from only the hot water storage tank 3. When hot water is supplied to the flow path 6 and the remaining hot water amount in the hot water storage tank 3 falls below the first set remaining hot water amount (or falls below the first set remaining hot water amount), the heat pump unit 1 is driven. The hot water machine 2 is driven when it falls below the second remaining hot water amount less than the first set remaining hot water amount (or less than the second set remaining hot water amount), and the first set remaining hot water amount is being executed during hot water supply control. The amount of remaining hot water is variably set so as to be able to cover the predicted amount of hot water used.

Incidentally, the remaining hot water amount control (hereinafter also referred to as “main control”) in the present embodiment shown in FIG. 3 and the comparative example shown in FIG. 5 have the same hot water supply load (the amount of hot water supplied to the hot water supply passage 6). Condition (180%). Further, since the capacity of the hot water machine 2 is doubled that of the heat pump unit 1, the 1 hour operation time by the hot water machine 2 corresponds to the 2 hour operation time of the heat pump unit 1. Therefore, the operation ratio of the heat pump unit 1 and the hot water machine 2 and the total of each operation time are as shown in Table 1. In Table 1, “HP” indicates a heat pump unit.

  As is apparent from Table 1, the operation rate of the heat pump unit 1 in the first time zone subject to the application of a cheap night charge is much larger in this control than in the comparative example, and the fuel cost is higher. The operation time of the hot water machine 2 is much shorter in this control than in the comparative example.

  In other words, in the comparative example, the first set remaining hot water amount is fixed to a constant amount in each of the first time zone and the second time zone, and even when the hot water is not supplied in the second time zone, Since the heat pump is always driven to store up to the first set remaining hot water amount below the 1 set remaining hot water amount, the remaining hot water amount reaches 85% at the time of 22:00 as shown in FIG. Therefore, only 15% is stored in the first time zone where the night charge is applied, and the cost merit is reduced. In the comparative example, since the second set remaining hot water amount in the second time is set as high as 50% in anticipation of safety, the hot water heater operates relatively quickly when the hot water supply load increases. Thus, as is apparent from Table 1, it can be seen that the total operation rate of the heat pump unit 1 per day is greatly improved in the present plan than in the comparative example.

  Further, in this control, the time until the hot water supply is actually started after the hot water tank 3 is filled by effectively using the first time zone is about 2 hours, whereas the comparison of FIG. In the example, it takes about 8 hours until the hot water supply is actually started after it is full. Compared to this control, the time until the stored hot water is actually supplied is extremely long. That is, since the heat radiation load becomes large, it is an obstacle to energy saving of the entire system.

  By the way, in embodiment mentioned above, it demonstrated by the example using the single heat pump unit 1 and the hot water machine 2, respectively. However, a plurality of heat pump units 1 and hot water machines 2 may be used.

  For example, a plurality of heat pump units 1 are arranged in parallel with respect to the hot water tank 3, and the control unit 4 drives the heat pump unit 1 according to the degree to which the amount of hot water stored in the hot water tank 3 is less than the set remaining hot water amount. The number of units is determined.

  In addition, a plurality of hot water machines 2 are arranged in parallel to the hot water tank 3, and the control unit 4 drives the hot water machine 2 according to the degree to which the amount of hot water stored in the hot water tank 3 is less than the set remaining hot water amount. It may be determined whether or not the number of hot water machines 2 to be driven is determined.

  Further, both the heat pump unit 1 and the water heater 2 may be arranged in parallel with each other with respect to the hot water tank 3. Also in this case, the control unit 4 determines the number of units to be driven according to the degree to which the hot water storage amount of the hot water storage tank 3 is less than the set remaining hot water amount.

As described above, the start / stop state of the heat pump unit 1 and the hot water machine 2 is set so that the set remaining hot water amount is set at the time when the remaining hot water amount control is being executed while the plurality of heat pump units 1 and the hot water machines 2 are arranged. By controlling and determining the number of units to be driven, for example, a large-scale public bath facility, hot spring facility, etc. can realize energy saving and CO ₂ saving, and a hot water supply system with low running cost can be realized. It can be easily provided according to the scale.

  As mentioned above, although this invention was demonstrated through embodiment mentioned above, as long as it does not deviate from the meaning of this invention, you may change a specific structure suitably.

For example, the heat pump unit 1 has been described assuming an efficient CO ₂ heat pump. However, the heat pump unit 1 is not necessarily limited to the heat pump unit 1 using a CO ₂ heat pump.

  Moreover, although demonstrated using the single hot water storage tank 3, as the hot water storage tank 3, a plurality of hot water storage tanks can be arranged in series. In the example described above, the hot water tank 3 is a vertical type, but it may be a horizontal type.

  Moreover, although the hot water machine 2 as a 2nd heat source comprised with the gas-fired vacuum type boiler, an oil-fired boiler etc. may be sufficient and it is not limited to a vacuum type.

    From the embodiment described above, the following hot water supply system is realized.

  (1) A hot water storage tank 3 and a hot water supply terminal 61 are attached, and a hot water supply passage 6 communicated and connected to the hot water storage tank 3, and a heat pump unit 1 connected in communication via the hot water storage tank 3 and the hot water storage main circulation flow path 7 ( The water heater 2 (second heat source), which has a heating capacity and heating cost relatively higher than those of the first heat source) and is connected to the hot water storage tank 3 via the hot water storage auxiliary circulation channel 8. ) And temperature sensors 9a to 9h (sensors) for detecting the remaining hot water amount in the hot water tank 3 in a stepless manner, and the remaining hot water amount control in the hot water tank 3 is performed in order to perform stable hot water supply to the hot water supply passage 6. And a control unit 4 (control means). The control unit 4 stores a predetermined amount of hot water heated by the heat pump unit 1 in the hot water storage tank 3 in advance, and is set occasionally during execution of the remaining hot water amount control. Heat pump unit 1 so that the amount of remaining hot water is set Fine the hot water supply system for controlling the start-stop state of the water heater 2.

According to such a configuration, a heat source (for example, the heat pump unit 1) that has a relatively low running cost but a poor hot water supply capability, and a heat source that has a high running cost but a high hot water supply capability (for example, a hot water machine 2). Since the on / off state of the two heat sources is controlled in accordance with the hot water supply load, sufficient hot water can be supplied without causing so-called “hot water out”. Then, since it is possible to reduce as much as possible operating time of a day total two heat sources to cover such hot water supply amount, energy saving, the saving CO _2. In addition, since it is possible to use up all the hot water made on the previous day, and to heat up the missing part using either the heat pump unit 1 or the hot water machine 2 on the same day, or both, It is possible to provide a hot water supply system that is money-saving with low running cost and has extremely high ability to cope with increase and decrease in hot water supply load.

  (2) The said control part 4 (control means) divides the working time (for example, 1 day) which performs remaining hot water amount control in a unit time zone (1 hour), and sets the said set remaining hot water amount for every past unit time zone. A hot water supply system that is set based on the actual hot water supply performance of the hot water supply so as to cover the required hot water supply amount to the hot water supply flow path 6 that is predicted at times during execution of the remaining hot water amount control.

  According to such a configuration, it is possible to control the amount of remaining hot water finely, and it is possible to further enhance the effect (1).

  (3) A plurality of the heat pump units 1 (first heat sources) are arranged in parallel to the hot water storage tank 3, and the control unit 4 (control means) is configured such that the amount of hot water stored in the hot water storage tank 3 is the set remaining hot water amount. The hot water supply system which determines the number of the heat pump units 1 driven according to the degree which fell below.

  According to such a configuration, it is possible to easily cope with the scale of a facility where a large amount of hot water supply is expected, such as a large public bath facility or a hot spring facility.

  (4) A plurality of the hot water machines 2 (second heat sources) are arranged in parallel with respect to the hot water storage tank 3, and the control unit 4 (control means) A hot water supply system that determines whether or not to drive the hot water machine 2 according to the degree to which the amount of hot water has fallen, and determines the number of hot water machines 2 to be driven.

  Even in such a configuration, it is possible to easily cope with a facility for which a large amount of hot water supply is expected, such as a large public bath facility or a hot spring facility.

  (5) A hot water supply system in which the heat pump unit 1 (first heat source) includes an electrically driven heat pump, and the water heater 2 (second heat source) uses fossil fuel.

  According to such a configuration, since an existing heat source that is stable in quality can be used instead of a special heat source, an unnecessary increase in cost can be suppressed when the above-described hot water supply system is realized.

  (6) A day that is an operation time is divided into a first time zone in which nighttime power is applied (for example, 22:00 to 8:00) and a second time zone in which daytime power is applied (for example, 8:00 to 22). And the set remaining hot water amount in the first time zone is set in advance to a constant amount based on the capacity of the hot water tank 3, and the control unit 4 (control means) controls the first time zone. In the hot water supply system, the heat pump unit 1 (first heat source) is preferentially driven.

  According to such a configuration, it is possible to effectively use cheap nighttime electric power and to provide an energy saving and cost saving hot water supply system.

DESCRIPTION OF SYMBOLS 1 Heat pump unit 2 Hot water machine 3 Hot water tank 4 Control part (control means)
5 Raw water supply flow path 6 Hot water supply flow path 7 Main circulation flow path for hot water storage 8 Auxiliary circulation flow path for hot water storage 9 Temperature sensor

Claims (3)

A hot water tank,
A hot water supply channel, to which a hot water discharge terminal is attached, and is connected to the hot water storage tank,
A first heat source connected in communication with the hot water storage tank via a hot water storage main circulation channel;
A heating capacity and heating cost relatively higher than those of the first heat source, and a second heat source connected in communication with the hot water storage tank via an auxiliary circulation channel for hot water storage;
A sensor for continuously detecting the amount of hot water in the hot water tank;
Control means for controlling the amount of remaining hot water in the hot water storage tank in order to perform stable hot water supply to the hot water supply flow path,
The control means includes
A predetermined amount of hot water heated by the first heat source is stored in the hot water storage tank in advance, and then the first heat source and the heat source are set so as to have a set remaining hot water amount set during execution of the remaining hot water amount control. A hot water supply system for controlling the on / off state of the second heat source,
While the first heat source is an electrically driven heat pump, the second heat source is a water heater using fossil fuel,
The control means stores one day, which is an operation time, by dividing it into a first time zone in which nighttime power is applied and a second time zone in which daytime power is applied, and a threshold value for remaining hot water control. The first set remaining hot water amount is stored,
If the amount of hot water in the hot water storage tank is less than the first set remaining hot water amount, the first heat source is operated, and if the first set remaining hot water amount exceeds the first set remaining hot water amount, 1 is a threshold value for stopping the operation of the heat source,
At least during the first time period, the first set remaining hot water amount is set to a predetermined amount in advance based on the capacity of the hot water storage tank, and the first heat source is preferentially driven, while in the second time period, The first set remaining hot water amount is gradually decreased every unit time zone while securing a remaining hot water amount sufficient to cover the usage amount ,
The control means further stores a second set remaining hot water amount that is relatively small with respect to the first set remaining hot water amount,
If the amount of hot water in the hot water storage tank is less than the second set remaining hot water amount, the second heat source is operated, and if the second set remaining hot water amount exceeds the second set remaining hot water amount, 2 is a threshold for stopping the operation of the heat source of
In the second time zone, the control means performs control so that the first set remaining hot water amount and the second set remaining hot water amount gradually approach each other, and thereafter a difference between the predetermined amounts is maintained. Hot water supply system. A plurality of the first heat sources are arranged in parallel to the hot water storage tank;
The control means includes
2. The hot water supply system according to claim 1, wherein the number of first heat sources to be driven is determined in accordance with a degree that a hot water storage amount of the hot water storage tank is less than the first set remaining hot water amount. A plurality of the second heat sources are arranged in parallel to the hot water storage tank;
The control means includes
Determining whether or not to drive the second heat source according to the degree to which the amount of hot water stored in the hot water storage tank is less than the second set remaining hot water amount, and determining the number of second heat sources to be driven; The hot water supply system according to claim 2 .

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