JP2010230175A - Hot water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable hot water supply system capable of surely storing hot water without lowering a temperature of the hot water while a minimum necessary number of heat pump type heat source machines are operated in a midnight power time zone. <P>SOLUTION: A hot water delivery flow rate Wa per unit time of each heat pump type heat source machine 2 is calculated from a water inflow temperature Wi to each heat pump type heat source machine 2, a set hot water delivery temperature Twa and an outside air temperature To. A necessary hot water storage amount Wn until hot water storage amount in a hot water storage tank 5 reaches a predetermined set hot water storage amount Wms is calculated from a remaining hot water amount Wm in the hot water storage tank 5 and the set hot water storage amount Wms. A time tn in the midnight power time zone from the start of the storage of hot water until the completion of the storage of hot water is calculated. The number N of the operating heat pump type heat source machines 2 in the midnight power time zone is calculated from the hot water delivery flow rate Wa, the necessary hot water storage amount Wn and the time tn. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hot water supply system including a plurality of heat pump heat source machines.

  There is known a hot water supply system in which hot water is generated by a plurality of heat pump heat source machines, the generated hot water is stored in a hot water storage tank, and a user can use the stored hot water as required (for example, Patent Document 1).

JP 2007-205698 A

  In a hot water supply system having a plurality of heat pump heat source units, from the viewpoint of energy saving and cost saving, operation is performed in the late-night power hours (for example, 22:00 to 8 o'clock), and the number of heat pump heat source units is the minimum necessary. It is desired that the hot water storage is completed immediately before the start of hot water supply.

  However, it is difficult to properly set the number of units to be operated.For example, even if hot water storage is completed before the last time of the midnight power hours, or when the hot water storage is completed before the last time of the midnight power hours, If the hot water storage is completed well before the final time, the hot water temperature may decrease.

  The present invention takes the above-mentioned circumstances into consideration, and its purpose is a reliability capable of reliably storing hot water without lowering the hot water temperature while operating the minimum number of heat pump heat source units in the midnight power hours. It is to provide an excellent hot water supply system.

  A hot water supply system according to a first aspect of the present invention controls a plurality of heat pump heat source devices that heat water to generate hot water, a hot water storage tank that stores hot water generated by these heat pump heat source devices, and the heat source devices. Control means, the control means, the hot water flow rate Wa per unit time of each heat pump type heat source machine, the incoming water temperature to each heat pump type heat source machine, a preset set hot water temperature, and Means for calculating from the outside air temperature, means for calculating the necessary hot water storage amount Wn until the hot water storage amount of the hot water storage tank reaches a predetermined hot water storage amount from the remaining hot water amount of the hot water storage tank and the set hot water storage amount, and midnight Means for calculating the time tn from the hot water storage start time to the hot water storage end time in the electric power time zone, and the number N of operating heat pump heat source units in the midnight electric power time zone, Wa, and means for calculating from the required amount of hot water storage Wn, and time tn.

  A hot water supply system according to a second aspect of the present invention controls a plurality of heat pump heat source devices that heat water to generate hot water, a hot water storage tank that stores hot water generated by these heat pump heat source devices, and the heat source devices. Each heat pump type heat source unit, and each heat pump type heat source unit has a hot water flow rate Wa per unit time, an incoming water temperature to each heat pump type heat source unit, a preset set hot water temperature, and an outside air temperature. And means for notifying the system controller of the calculated hot water flow rate Wa. The system control unit calculates a necessary hot water storage amount Wn until the hot water storage amount of the hot water storage tank reaches a predetermined hot water storage amount from the remaining hot water amount of the hot water storage tank and the predetermined hot water storage amount, Means for calculating the time tn from the hot water start time to the hot water end time in the midnight power time zone, and the number N of operating heat pump heat source units in the midnight power time zone, the hot water flow rate Wa, the required hot water storage amount Wn, and the time tn And calculating means.

  According to the hot water supply system of the present invention, it is possible to reliably store hot water without lowering the hot water temperature while operating the minimum number of heat pump heat source units in the late-night power hours.

The figure which shows the structure of 1st Embodiment of this invention. The flowchart for demonstrating the effect | action of 1st Embodiment. The figure which shows the relationship between the external temperature in 1st Embodiment, and the outgoing hot water flow rate as a hot water temperature. The figure which shows the structure of 2nd Embodiment of this invention. The flowchart for demonstrating the effect | action of 2nd Embodiment. The flowchart for demonstrating the effect | action of 3rd Embodiment. The figure which shows the relationship between the time concerning 4th Embodiment, and the number of driving | operations. The figure which shows the relationship between the time set in 4th Embodiment, and a driving | operation number.

[1] A first embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, a plurality of heat pump heat source devices 2 and a sealed system tank 3 are connected to a water pipe 1 connected to a water supply source (not shown). Each heat pump type heat source device 2 has a heat pump type refrigeration cycle 10 and generates hot water by heating the water flowing in from the water pipe 1 through a water heat exchanger (not shown) of the heat pump type refrigeration cycle 10. .

  Hot water generated by each heat pump heat source device 2 is supplied to the system tank 3 and the open hot water storage tank 5 through the hot water pipe 4. In each heat pump type heat source device 2, a water temperature sensor 11 is attached to the water pipe 1, and a hot water temperature sensor 12 is attached to the hot water pipe 4. The water temperature sensor 11 and the hot water temperature sensor 12 are connected to the control unit 20 of the heat pump heat source unit 2 together with the outside air temperature sensor 13.

The control part 20 of each heat pump type heat source machine 2 has the following means (1) and (2) as main functions.
(1) The hot water flow rate (also referred to as heating capacity) Wa per unit time to the hot water pipe 4 is set to the incoming water temperature (detected temperature of the water temperature sensor 11) Twi, a predetermined set hot water temperature Twa, and the outside air temperature (outside Means for calculating from the temperature detected by the air temperature sensor 13 To

  (2) Means for notifying the system control unit 30 described later of the calculated hot water flow rate Wa.

  The hot water storage tank 5 stores hot water supplied from each heat pump heat source machine 2 and has a hot water amount sensor 6 for detecting the amount of hot water stored (remaining hot water amount) Wm. A hot water supply pipe 7 is connected to the lower part of the hot water storage tank 5, and a hot water supply pump 8 is provided in the middle of the hot water supply pipe 7. By the operation of the hot water supply pump 8, the hot water in the hot water storage tank 5 is supplied to the user side.

  On the other hand, to the system control unit 30, the control unit 20, the hot water sensor 6, the operation unit 31, the display unit 32, and the clock 33 of each heat pump heat source machine 2 are connected.

The system control unit 30 includes the following means (11) to (14) as main functions.
(11) The hot water storage amount Wn required for the hot water storage tank 5 to reach the set hot water storage amount Wms, the remaining hot water amount (detected hot water amount of the hot water sensor 6) Wm and the set hot water storage amount until reaching the set hot water storage amount Wms. Means to calculate from Wms.

  (12) Means for calculating a time tn from a hot water storage start time set mainly in a late-night power time zone from 22:00 to 8:00 the next morning to a hot water storage end time set.

  (13) The operating number N of each heat pump heat source unit 2 in the time zone set mainly in the late-night power time zone, the hot water flow rate Wa notified from each heat pump type heat source unit 2, the calculated necessary hot water storage amount Wn, and A means for calculating every predetermined time (for example, one hour) ts based on the calculated time tn.

  (14) Means for operating the calculated number N of heat pump heat source units 2 among the heat pump type heat source units 2 at a time tn from the hot water storage start time to the hot water storage end time based on the clock 33.

Next, the operation will be described with reference to the flowchart of FIG.
When the night hot water storage operation is set in the operation unit 31 (YES in step 101), when the time of the clock 33 reaches the hot water storage start time preset in the operation unit 31 (YES in step 102), each heat pump type The hot water flow rate Wa per unit time of the heat source unit 2 is calculated based on each incoming water temperature Twi, a preset hot water temperature Twa, and an outside air temperature To (step 103).

  Subsequently, the necessary hot water storage amount Wn until the hot water storage amount of the hot water storage tank 5 reaches a predetermined hot water storage amount Wms is calculated based on the remaining hot water amount Wm of the hot water storage tank 5 and the set hot water storage amount Wms (step). 104). Further, a time tn from the hot water storage start time to the hot water storage end time in the midnight power time zone is calculated (step 105). The hot water storage start time and the hot water storage end time can be freely set in advance by the operation unit 31.

  Further, the operating number N of each heat pump heat source unit 2 in the midnight power time zone is calculated based on the tapping flow rate Wa of each heat pump type heat source unit 2, the calculated required hot water storage amount Wn, and the calculated time tn. (Step 106). Then, among the heat pump heat source units 2, the calculated number N of heat pump heat source units 2 are operated (step 107). Along with the start of the operation, a time count t1 is executed by the clock 33 (step 108), and the time count t1 is compared with a predetermined time ts (step 109). When the time count t1 does not reach the predetermined time ts (NO in step 109) and is not the hot water storage end time preset in the operation unit 31 (NO in step 110), the operation of the same number N is continued. (Step 107).

  As for which of the heat pump heat source devices 2 to operate, the operation time of each heat pump heat source device 2 is integrated, and the heat pump heat source devices 2 are operated in order from the shortest integration time.

  When the time count t1 reaches the predetermined time ts (YES in step 109), the time count t1 is cleared (step 111), the processing from step 101 is repeated, and the number N of operating units is newly calculated (step 106). ). Then, the newly calculated number N of heat pump heat source units 2 are operated (step 107).

  When the preset hot water storage end time is reached (YES in step 110), the time count t1 is cleared (step 111), and the process returns to step 101. In this case, since it is the hot water storage end time, the determination in step 102 is NO, and all the operations of the heat pump heat source device 2 in operation are stopped (step 112).

A specific example will be described.
When the operation start time is 22:00, the operation end time is 8:00 the next morning, the remaining hot water amount Wm of the hot water storage tank 5 at the operation start time is 1,000 (L; liter), and the set hot water storage amount Wms is 10,000 (L). 9,000 (L) is calculated as the required hot water storage amount Wn.

  As shown in FIG. 3, the hot water flow rate Wa per unit time of each heat pump heat source unit 2 is determined by using the set hot water temperature Twa, the outside air temperature To, and the incoming water temperature Twi as parameters. That is, under the conditions of the set hot water temperature Twa = 65 (° C.) and the outside air temperature To = 16 (° C.), the incoming water temperature Twi = 17 (° C.), the hot water flow rate Wa per unit time is 250 (L / h).

The time tn from the operation start time 22:00 to the operation end time 8 o'clock is 10 hours, and the following condition is satisfied with respect to the number N of operation.
Wn = 9000 = Wa · N · tn = 250 · N · 10
When the number of operating vehicles N is obtained from this condition, N = 9000/2500 = 3.6. Since the number of operating units including a decimal point is impossible in reality, “4” in the form of rounding off “3.6” is the operating number N.

  However, in the operation with the number of operating units raised to four, the amount of hot water stored in the hot water storage tank 5 reaches the set hot water storage amount Wms (= full tank) at, for example, 7:00 before the operation end time of 8:00. In this state, the heat of the hot water stored in the hot water storage tank 5 escapes through the wall surface of the hot water storage tank 5 for one hour from 7:00 to 8:00 of the operation end time, leading to a decrease in the hot water temperature. In addition, when hot water in the hot water storage tank 5 is used during operation, or when a change in the incoming water temperature Twi, a change in the outside air temperature To, a failure, or the like occurs in the heat pump heat source device 2 during operation, the operation end time 8 Sometimes, it may be less than the set hot water storage amount Wms.

  However, since the operation number N is calculated every hour from the operation start time 22:00 to the operation end time 8:00, the optimum operation number N according to the situation can be set sequentially. Therefore, the set hot water storage amount Wms can be ensured without a decrease in hot water temperature at the operation end time of 8:00. And since it is the minimum required number of operation N, while being able to obtain an energy saving effect, noise can be reduced.

[2] A second embodiment will be described. In the drawings, the same portions as those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.
As shown in FIG. 4, the system tank 3 is removed, and a hot water inlet of the reheater 40 is connected to a position of the hot water supply pipe 7 before the hot water supply pump 8 via a hot water pipe 41 and a pump 42. The hot water outlet of the machine 40 is communicated with the lower part of the hot water storage tank 5 through the hot water pipe 43.

  Based on a command from the system control unit 30, the reheater 40 periodically operates the pump 42 during hot water storage operation to take in hot water in the hot water storage tank 5, and whether the temperature of the hot water taken is below a predetermined value. Determine whether or not. Then, the reheater 40 determines that reheating is necessary if it is a predetermined value, for example, 60 (° C.) or less, and continues the operation of the pump 42 to take in hot water in the hot water storage tank 5, It is heated by a heat pump type refrigeration cycle or an electric heater and supplied to the hot water storage tank 5.

  However, since the reheater 40 is a device that raises hot water of 60 (° C.) to a higher level of 65 (° C.), for example, the operation efficiency is higher than that of the heat pump heat source device 2 that heats normal low temperature water. There is a feature of being bad. That is, it is desirable to operate each heat pump type heat source machine 2 well so that it may not depend on operation of the reheating machine 40 very much.

  Therefore, a hot water temperature sensor 50 is provided in the hot water storage tank 5, and the hot water temperature sensor 50 is connected to the system control unit 30.

  As shown in the flowchart of FIG. 5, the system control unit 30 compares the hot water temperature Th detected by the hot water temperature sensor 50 with a set value Ths, for example, 65 (° C.) (step 121). When the hot water temperature Th is 65 (° C.) or higher (YES in step 121), the system control unit 30 keeps the set hot water temperature Twa of each heat pump heat source unit 2 at, for example, a normal 65 (° C.) (step 122). ), When the hot water temperature Th is less than 65 (° C.) (NO in step 121), the set hot water temperature Twa is increased to, for example, 75 (° C.) (step 123).

  The operating efficiency of each heat pump heat source device 2 is worse when the set hot water temperature Twa is 75 (° C.) than when 65 (° C.), but is much better than the deterioration of the operating efficiency of the reheater 40. .

  Thus, the operating rate of the reheating machine 40 can be reduced by adjusting the set hot water temperature Twa of each heat pump heat source machine 2 according to the hot water temperature Th. Thereby, the energy saving effect can be improved.

  Other configurations, operations, and effects are the same as those in the first embodiment. Therefore, the description is omitted.

[3] A third embodiment will be described. In the drawings, the same portions as those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.
Here, the system control unit 30 has the following means (21) to (26) instead of the means (11) to (14) of the first embodiment.
(21) The necessary hot water storage amount Wn until the hot water storage amount of the hot water storage tank 5 reaches a preset hot water storage amount Wms is determined from the remaining hot water amount (detected hot water amount of the hot water sensor 6) Wm and the set hot water storage amount Wms of the hot water storage tank. Means to calculate.

  (22) A means for calculating a time tn from the hot water storage start time to the hot water storage end time in the late-night power hours from 22:00 to 8:00 the next morning.

  (23) Based on the number N of operating heat pump heat source units 2 in the midnight power time zone, the hot water flow rate Wa notified from each heat pump type heat source unit 2, the calculated required hot water storage amount Wn, and the calculated time tn. Means to calculate.

  (24) When the calculated operation number N is not an integer, a value obtained by rounding down the decimal point of the operation number N for a predetermined time from the hot water start time is set as the new operation number Na, and the remaining time until the hot water end time Time is a means for setting a value obtained by rounding up the number of decimal places of the operating number N as a new operating number Nb.

  (25) When the calculated operation number N is an integer, among the heat pump heat source units 2, the calculated operation number N of heat pump type heat source units 2 are counted from the hot water storage start time based on the time measured by the clock 33. Means for driving at time tn until the hot water storage end time.

  (26) When the calculated operation number N is not an integer, the heat pump heat source unit 2 of the set operation number Na is operated based on the time of the clock 33 for a predetermined time from the hot water start time and until the hot water storage end time. Means for operating the heat pump type heat source unit 2 of the set number Nb of operation based on the time of the clock 33.

The operation will be described with reference to the flowchart of FIG.
The operating number N of each heat pump heat source device 2 in the midnight power time zone is calculated based on the tapping flow rate Wa of each heat pump heat source device 2, the calculated required hot water storage amount Wn, and the calculated time tn (step). 106).

  When the calculated operation number N is not an integer (YES in step 131), a value obtained by rounding down the decimal point of the operation number N for a predetermined time from the hot water storage start time is set as a new operation number Na, and the heat pump type of the operation number Na As the heat source unit 2 is operated, the remaining time until the hot water storage end time is set as a new operating number Nb by rounding up the decimal point of the operating number N, and the heat pump heat source unit 2 of the operating number Nb is operated. (Step 132).

  When the calculated operating number N is an integer (NO in step 131), the calculated number N of operating heat pump heat source units 2 is operated (step 133).

A specific example will be described.
When the operation start time is 22:00, the operation end time is 8:00 the next morning, the remaining hot water amount Wm of the hot water storage tank 5 at the operation start time is 1,000 (L), and the set hot water storage amount Wms is 10,000 (L), the necessary hot water storage 9,000 (L) is calculated as the amount Wn.

  As shown in FIG. 3, the hot water flow rate Wa per unit time of each heat pump type heat source device 2 has a characteristic that is determined by using the set hot water temperature Twa, the outside air temperature To, and the incoming water temperature Twi as parameters. That is, under the conditions of the set hot water temperature Twa = 65 (° C.) and the outside air temperature To = 16 (° C.), the incoming water temperature Twi = 17 (° C.), the hot water flow rate Wa per unit time is 250 (L / h).

The time tn from the operation start time 22:00 to the operation end time 8 o'clock is 10 hours, and the following equation is established with respect to the number N of operations.
Wn = 9000 = Wa · N · tn = 250 · N · 10
When the number of operating units N is obtained, N = 9,000 / 2500 = 3.6 units. Since the number of operating units including a decimal point is impossible in reality, 3.6 units are rounded to N = 4 units.

  However, in an operation in which the number of operating units that should be 3.6 units is raised to four units, as shown in FIG. 7, the hot water storage amount of the hot water storage tank 5 is set at 7 o'clock before the operation end time 8 o'clock. (= Full), at which point the operation will be stopped. In this state, the heat of the hot water stored in the hot water storage tank 5 escapes through the wall surface of the hot water storage tank 5 for 1 hour from 7:00 to 8:00, and the hot water temperature is lowered.

  Therefore, when the operating number N = 3.6 is calculated, as shown in FIG. 8, the value “3” obtained by rounding off the decimal point of the operating number N for 4 hours from the hot water start time is the new operating number Na. For the remaining 6 hours until the hot water storage end time, a value “4” rounded up below the decimal point of the number N of operating units is set as the new number Nb of operating units.

  In this manner, by adjusting the number N of operations, the set hot water storage amount Wms can be reliably ensured without a decrease in hot water temperature at the operation end time of 8:00.

  Other configurations, operations, and effects are the same as those in the first embodiment. Therefore, the description is omitted.

[4] Modification
In addition, in each said embodiment, there is no limitation about the number of the heat pump type heat source machines 2, and it can select suitably according to the usage-amount of the hot water by the user side. In addition, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. It is also possible to delete some components from all the components shown in each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Water pipe, 2 ... Heat pump type heat source machine, 4 ... Hot water pipe, 5 ... Hot water storage tank, 6 ... Hot water quantity sensor, 7 ... Hot water supply pipe, 8 ... Hot water supply pump, 10 ... Heat pump refrigeration cycle, 11 ... Incoming water temperature sensor, 12 DESCRIPTION OF SYMBOLS ... Hot water temperature sensor, 13 ... Outside temperature sensor, 20 ... Control part, 30 ... System control part, 31 ... Operation part, 32 ... Display part, 33 ... Clock, 40 ... Reheater, 50 ... Hot water temperature sensor

Claims (4)

In a hot water supply system comprising a plurality of heat pump heat source devices that heat water to generate hot water, a hot water storage tank that stores hot water generated by these heat pump heat source devices, and a control means that controls each of the heat source devices,
The control means includes
Means for calculating the hot water flow rate Wa per unit time of each heat pump heat source unit from the incoming water temperature to each heat pump type heat source unit, a predetermined set hot water temperature, and the outside air temperature;
Means for calculating a necessary hot water storage amount Wn until the hot water storage amount of the hot water storage tank reaches a set hot water storage amount from a remaining hot water amount of the hot water storage tank and the set hot water storage amount;
Means for calculating a time tn from the hot water storage start time to the hot water storage end time in the midnight power time zone;
Means for calculating the number N of operation of each heat pump heat source unit in the late-night power hours from the hot water flow rate Wa, the necessary hot water storage amount Wn, and the time tn;
A hot water supply system characterized by comprising: In a hot water supply system comprising a plurality of heat pump heat source devices that heat water to generate hot water, a hot water storage tank that stores hot water generated by these heat pump heat source devices, and a system control unit that controls each of the heat source devices. ,
Each of the heat pump heat source units calculates a hot water flow rate Wa per unit time from the temperature of the incoming water to each of the heat pump heat source units, a predetermined set hot water temperature, and the outside air temperature, and the calculated hot water temperature. Means for notifying the system controller of the flow rate Wa,
The system control unit calculates a necessary hot water storage amount Wn until the hot water storage amount of the hot water storage tank reaches a set hot water storage amount from the remaining hot water amount of the hot water storage tank and the set hot water storage amount, and starts hot water storage in the midnight power hours The means for calculating the time tn from the time to the hot water storage end time, and the number N of operating each heat pump heat source machine in the midnight power time zone are calculated from the hot water flow rate Wa, the necessary hot water storage amount Wn, and the time tn. Having means,
A hot water supply system characterized by that.   The hot water supply system according to claim 1 or 2, wherein the means for calculating the number N of operating units executes the calculation every predetermined time from the start of hot water storage. When the calculated operation number N is not an integer, a value obtained by rounding off the decimal point of the operation number N is set as a new operation number for a predetermined time from the hot water storage start time, and the remaining time until the hot water storage end time is the operation number Means for setting a value obtained by rounding up the decimal point of N as a new operating number;
The hot water supply system according to claim 1 or 2, further comprising:

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