JP2019190741A - Storage-type hot water supply device - Google Patents

Abstract

To provide a storage-type hot water supply device capable of operating a heat pump heat source machine at a low output and improving an energy saving characteristic.SOLUTION: A storage-type hot water supply device comprises a hot water storage tank, a heat pump heat source machine, an auxiliary heat source machine, and control means for estimating a future hot water usage on the basis of a hot water usage history and for operating the heat pump heat source machine so as to control to perform the hot water storage of an estimated heat amount corresponding to a hot water usage estimated amount before a hot water supply estimated time. The heat pump heat source machine can adjust an output in an output range between a predetermined upper limit output and a lower limit output. The control means calculates an output of the heat pump heat source machine when performing the hot water storage of the estimated heat amount during a time ranging from a present time to the hot water supply estimated time, stands by when the calculated output is lower than the lower limit output, starts an operation of the heat pump heat source machine at the calculated output when the calculated output is in an output range, and starts an operation of the heat pump heat source machine at the upper limit output when the calculated output is larger than the upper limit output.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hot water storage hot water supply apparatus including a heat pump heat source device, an auxiliary heat source device, and a hot water storage tank. The present invention relates to a hot water storage hot water supply apparatus.

  Conventionally, the future hot water usage is predicted based on the past hot water usage history, and the heat pump heat source machine is operated before the predicted hot water supply time to supply hot water of the amount corresponding to the predicted hot water usage to the hot water storage tank. Hot water storage hot water storage devices that store hot water are widely used. Such a hot water storage and hot water supply device operates a heat pump heat source machine with high operating efficiency at a rated output (upper limit output in specifications), and completes the storage of the amount of heat predicted based on the hot water supply usage history immediately before using the hot water supply. Therefore, hot water that is not used even when hot water is stored and there is little heat dissipation loss and is excellent in energy saving, but further improvement in energy saving is also required.

  The coefficient of performance (COP) of the heat pump heat source machine during hot water storage has a great influence on the energy saving performance. Further, in the heat pump heat source device, the COP is improved as the output is adjusted to be lower. Therefore, in order to improve energy saving, it has been studied to store hot water at a low output by adjusting the output of the heat pump heat source so that the COP becomes high.

  Low-power operation reduces the amount of hot water stored per unit time, so hot water storage cannot be completed by the predicted hot water use time. Therefore, the hot water running out of hot water that can be discharged from the hot water storage tank while using hot water is generated. Complementing the shortage of hot water with an auxiliary heat source machine will reduce energy savings, so hot water storage is completed by the predicted hot water use time by accelerating the hot water start time according to the low output operation of the heat pump heat source machine Let

  As a hot water storage and hot water supply apparatus that adjusts the output of a heat pump heat source machine and stores hot water, a hot water storage and hot water supply apparatus that includes a heat pump heat source apparatus that can adjust the output in a plurality of stages is known, for example. This hot water storage hot water supply device calculates the output of the heat pump heat source unit required for hot water storage, and when the hot water is stored by alternately switching the output of the two stages of lower output than the calculated output and higher output than the calculated output, By adjusting the ratio of the time to the high output time, the average output is matched with the calculated output.

Japanese Patent Laid-Open No. 2006-61553

  However, the hot water storage hot water supply apparatus of Patent Document 1 requires a certain amount of time until the output is stabilized every time the output of the heat pump heat source apparatus is switched during hot water storage. During this time, the heat pump heat source apparatus is operated with a low COP. Therefore, COP does not improve and energy saving cannot be improved. In addition, the hot water storage temperature varies every time the output is switched, and the temperature of the hot water stored in the hot water storage tank may not be uniform.

  The objective of this invention is providing the hot water storage hot-water supply apparatus which can drive a heat pump heat-source machine by low output, and can improve energy saving property.

  The invention of claim 1 predicts future hot water supply usage based on a hot water storage tank, a heat pump heat source device, an auxiliary heat source device, and a history of hot water supply usage, and operates the heat pump heat source device before the predicted hot water supply time. In the hot water storage hot water supply apparatus having a control means for controlling the predicted heat quantity corresponding to the predicted hot water supply usage amount to store in the hot water storage tank, the output of the heat pump heat source unit is an output range between a predetermined upper limit output and a lower limit output. The control means calculates the output of the heat pump heat source device when storing the predicted amount of hot water in the time from the current time to the predicted hot water supply time, and the calculated output is less than the lower limit output. If the calculated output is within the output range, operation of the heat pump heat source machine is started with the calculated output, and the calculated output is equal to the upper limit output. Again large is characterized by starting the operation of the heat pump heat source device by the upper output.

  According to the above configuration, since the heat pump heat source device can be operated at a lower output than the upper limit output during hot water storage, the lower the output, the higher the COP of the heat pump heat source device, which increases the energy saving performance of the hot water storage hot water supply device. It can be improved.

  The invention of claim 2 is characterized in that, in claim 1, the control means adds a heat dissipation loss in a time from the current time to the predicted hot water supply time to the predicted heat quantity.

  According to the above configuration, it is possible to store hot water in consideration of heat dissipation loss that increases because the time required for hot water storage becomes longer due to the low output operation of the heat pump heat source unit, and the predicted amount of heat is reliably stored by the time of hot water use. You can avoid running out of hot water while using hot water.

  A third aspect of the invention is characterized in that, in any one of the first and second aspects, the control means calculates the output of the heat pump heat source unit at predetermined intervals.

  According to the above configuration, since the operation of the heat pump heat source device can be calculated and started every predetermined period, the low output operation opportunity of the heat pump heat source device is increased, and the energy saving performance of the hot water storage hot water supply device can be improved.

  According to the hot water storage hot water supply apparatus of the present invention, the heat pump heat source device can be operated at a low output to improve energy saving.

It is a figure which shows the whole structure of the hot water storage hot-water supply apparatus concerning the Example of this invention. It is a flowchart of the output calculation of the heat pump heat source machine which concerns on the Example of this invention. It is explanatory drawing of calculation output.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

Initially, the whole structure of the hot water storage hot-water supply apparatus 1 of this invention is demonstrated based on FIG.
The hot water storage hot water supply apparatus 1 includes a heat pump heat source unit 2 and a hot water storage hot water supply unit 3. The hot water storage hot water supply unit 3 performs, for example, a hot water storage tank 5 for storing hot water heated by the combustion-type auxiliary heat source device 4, the heat pump heat source device 2, and hot water usage prediction based on the hot water usage history and the predicted hot water usage amount. A control unit 7 (control means) for controlling the amount of heat (predicted amount of heat) corresponding to (predicted amount of hot water supply) to be stored in the hot water storage tank 5 before using the hot water supply is provided.

  The heat pump heat source unit 2 heats the hot water to the target hot water storage temperature by the heat absorbed from the outside air and stores the hot water in the hot water storage tank 5. Hot water stored in the hot water storage tank 5 by the operation of the heat pump heat source device 2 is used for hot water supply or filling of the bathtub 19. When hot water in the hot water storage tank 5 cannot be supplied at the hot water supply set temperature, hot water is heated by burning the fuel in the auxiliary heat source unit 4. The hot water supply set temperature can be set to a desired temperature by a user from an operation terminal (not shown), and the target hot water storage temperature is set higher than the hot water supply set temperature by the control unit 7.

  A hot water discharge passage 11 for discharging hot water stored in the hot water storage tank 5 is connected to the upper part of the hot water storage tank 5. The hot water passage 11 is provided with a hot water temperature sensor 11 a for detecting the hot water temperature of hot water supplied to the hot water mixing valve 12 through the hot water passage 11. A hot water supply passage 13 is connected to the lower part of the hot water storage tank 5 to supply hot water to the hot water storage tank 5 from an upper water source. A water supply temperature sensor 13 a for detecting the water supply temperature is disposed in the water supply passage 13.

  The water supply bypass passage 14 branches from the water supply passage 13 and is connected to the hot water / mixing valve 12. The hot water mixing valve 12 adjusts and mixes the mixing ratio of the hot water in the outlet hot water passage 11 and the upper water of the water supply bypass passage 14 for hot water supply at a hot water supply set temperature. A hot water supply passage 16 is connected to the hot water mixing valve 12, and hot water mixed by the hot water mixing valve 12 and adjusted to a hot water supply set temperature can flow through the hot water supply passage 16 and supply hot water to a hot water tap or the like not shown.

  Further, the hot water mixed by the hot water / water mixing valve 12 can be filled in the bathtub 19 via the hot water filling passage 18 branched from the hot water supply passage 16 and connected to the memorial circuit 17. The hot-water supply passage 16 is provided with a hot-water supply temperature sensor 16a for detecting the hot-water supply temperature and a hot-water supply flow rate sensor 16b for detecting the hot-water supply flow rate, and the hot-water supply passage 18 is provided with an on-off valve 18a that opens when the hot-water supply is filled. ing.

  An upstream heating passage 21 a that supplies hot water to the heat pump heat source device 2 is connected to the lower portion of the hot water storage tank 5, and a downstream heating passage 21 b that supplies hot water heated by the heat pump heat source device 2 to the hot water storage tank 5 is an upper portion of the hot water storage tank 5. A circulation heating circuit 21 is formed between the hot water storage tank 5 and the heat pump heat source unit 2 so that hot water can be circulated by the circulation pump 22. During hot water storage, the temperature detected by the temperature sensor 21c disposed in the downstream heating passage 21b is controlled to be the target hot water storage temperature set by the control unit 7.

  On the outer periphery of the hot water storage tank 5, a plurality of hot water temperature sensors 5a to 5e for detecting the temperature of the hot water stored therein are arranged at predetermined intervals in the vertical direction. The hot water temperature sensors 5a to 5e can detect the temperature of hot water stored and the amount of hot water at that temperature. The hot water storage temperature sensors 5a to 5e and the hot water storage tank 5 are covered with a heat insulating material (not shown) that reduces heat dissipation of the stored hot water.

  An auxiliary heating passage 23 for heating the hot water in the hot water storage tank 5 with the auxiliary heat source device 4 is branched from the hot water passage 11 and connected to the auxiliary heat source device 4. An auxiliary hot water passage 24 for discharging hot water heated by the auxiliary heat source device 4 is connected to the hot water supply passage 11 on the downstream side of the branch portion of the auxiliary heating passage 23. The adjustment valve 25 disposed in the auxiliary hot water passage 24 adjusts the amount of hot water supplied from the auxiliary hot water passage 24 to the hot water passage 11. In the auxiliary heating passage 23, a three-way valve 26 and a pump 27 for sending hot water to the auxiliary heat source unit 4 are arranged.

  A heat exchanger passage 28 branched from the auxiliary hot water passage 24 is connected to the three-way valve 26. The three-way valve 26 is switched so that hot water in the hot water storage tank 5 or hot water in the heat exchanger passage 28 can be supplied to the auxiliary heat source unit 4. The heat exchanger passage 28 is provided with a heat exchanger 28a and an on-off valve 28b. The heat exchanger 28 a is used for a chasing operation in which hot water in the bathtub 19 flowing through the chasing circuit 17 is heated by heat exchange with hot water heated by the auxiliary heat source unit 4 by the operation of the chasing pump 29. Further, a branch passage portion 13 b branched from the water supply passage 13 is connected to the heat exchanger passage 28 so that clean water can be supplied to the heat exchanger passage 28.

  The heat pump heat source device 2 is configured by connecting a compressor 32, a condensation heat exchanger 33, an expansion valve 34, and an evaporation heat exchanger 35 by a refrigerant circuit 36. The heat pump heat source unit 2 compresses the refrigerant enclosed in the refrigerant circuit 36 by the compressor 32 to a high temperature, and the hot water flowing through the circulation heating circuit 21 by the circulation pump 22 is converted into a high-temperature refrigerant in the condensation heat exchanger 33. Heat by heat exchange. The refrigerant after the heat exchange expands at the expansion valve 34 and becomes cooler than the outside air, absorbs heat from the outside air at the evaporating heat exchanger 35, and is then introduced into the compressor 32 again. The output of the heat pump heat source device 2 can be adjusted by changing driving conditions such as the rotational speed of the compressor 32.

  The evaporative heat exchanger 35 includes an outside air temperature sensor 35a for detecting the outside air temperature and a blower 35b. Moreover, the heat pump heat source device 2 includes a heat pump control unit 37 that controls the compressor 32, the expansion valve 34, the blower 35b, and the like. The heat pump control unit 37 is communicably connected to the control unit 7 which is a main control unit of the hot water storage hot water supply apparatus 1 and controls the operation so as to adjust the output of the heat pump heat source device 2 in accordance with an instruction from the control unit 7. The upper limit output and the lower limit output of the adjustable output range of the heat pump heat source unit 2 are determined by the range in which the compressor 32 can be stably driven and the outside air temperature. The lower the outside air temperature, the lower the upper limit output and the lower limit output. The upper limit output under a predetermined condition is the rated output. The heat pump heat source unit 2 takes about 10 minutes at maximum until the heat pump cycle is stabilized after startup or after changing the operating conditions.

  The control unit 7 controls hot water supply and the like based on detection signals from various sensors, and learns and stores hot water use conditions such as the amount of hot water used, the time of hot water use, and various temperatures at that time. Based on the learned hot water usage history (hot water usage history), the controller 7 periodically predicts future hot water usage every predetermined period (for example, every 5 minutes). In the hot water use prediction, the next hot water use time to be predicted (predicted hot water time), the amount of heat corresponding to the predicted amount of hot water supply (predicted heat amount), and the like are set. And the control part 7 calculates the output of the heat pump heat source unit 2 so that the hot water storage of the predicted heat amount is completed before the hot water supply prediction time based on the hot water supply use prediction. This output calculation will be described based on the flowchart of FIG. Si (i = 1, 2,...) In the figure represents a step.

  First, in S1, the current hot water storage amount A [J] is calculated from the temperature and the amount of hot water stored in the hot water storage tank 5 at the current time t0, and the process proceeds to S2. The current hot water storage heat amount A can also be calculated from the hot water supply usage history and heat dissipation loss.

  Next, in S2, a future hot water supply use prediction is performed based on the hot water supply use history, and the process proceeds to S3. The predicted hot water supply time t1 and the predicted heat quantity B [J] are set by this hot water supply use prediction.

  Next, in S3, a hot water storage period T [s] from the current time t0 to the predicted hot water supply time t1 is calculated, and the process proceeds to S4. At this time, the heat dissipation loss amount H [J] in the hot water storage period T is also calculated. The heat dissipation loss amount H is calculated based on, for example, the hot water storage period T, the loss coefficient, and the hot water storage amount.

  Next, in S4, a required time α [s] from the start of the heat pump heat source device 2 to stabilization at the rated output is set, and the process proceeds to S5. The required time α may be a preset constant value, or may use an actual value based on the hot water supply usage history.

  Next, in S5, the output (calculated output P [W]) of the heat pump heat source unit 2 is calculated by calculation based on the current hot water storage amount A, the predicted heat amount B, the hot water storage period T, and the required time α, and the process proceeds to S6. . The calculated output P is an output when the hot water storage of the amount of heat to be stored is completed at the predicted hot water supply time t1, and specifically, P = (B−A) / (T−α). The calculated heat output P considering the heat dissipation loss may be calculated by adding the heat dissipation loss amount H in the hot water storage period T to the predicted heat amount B, that is, P = (B + HA− / T−α). Even if the hot water storage period T is long, occurrence of hot water shortage can be suppressed.

  Next, in S6, it is determined whether or not the calculated output P is smaller than the lower limit output of the heat pump heat source unit 2. The lower limit output uses the lower limit output in the specification, but may be calculated based on the detected temperature (outside air temperature) of the outside air temperature sensor 35a. When the determination is Yes, the process proceeds to S7, does not start the operation of the heat pump heat source unit 2, waits until the next output calculation, and returns to S1. If the determination is No, the process proceeds to S8.

  Next, in S8, it is determined whether or not the calculated output P is larger than a predetermined upper limit output of the heat pump heat source unit 2. The upper limit output also uses the upper limit output in the specification, but may be calculated based on the outside air temperature. When the determination is Yes, the process proceeds to S9, the operation of the heat pump heat source unit 2 is started at the upper limit output, and the process returns. If the determination is No, that is, if the calculated output P is greater than or equal to the lower limit output and less than or equal to the upper limit output, the process proceeds to S10, and the operation of the heat pump heat source unit 2 starts with the calculated output P and returns.

  When the operation of the heat pump heat source device 2 is started, other operation conditions such as a target hot water storage temperature in the hot water storage of the amount of heat (BA) to be stored from now on and the number of revolutions of the circulation pump 22 are also set. The COP of the heat pump heat source device 2 is improved as the target hot water storage temperature is lower. However, since the temperature stratification formed in the hot water storage tank 5 is disturbed if the hot water temperature is lower than the hot water storage tank 5 currently stored, The temperature is not set lower than the hot water temperature stored in the tank 5.

Next, the operation and effect of the hot water storage hot water supply apparatus 1 of the present invention will be described.
As shown in FIG. 3, at the current time t0, the current hot water storage heat amount A is calculated, hot water supply use prediction is performed, and the predicted hot water supply time t1 and the predicted heat amount B are set. Further, the hot water storage period T from the current time t0 to the predicted hot water supply time t1 is calculated, and the required time α until the stable operation of the heat pump heat source unit 2 is set. And the calculation output P is calculated by the calculation based on the hot water storage A, the predicted heat B, the hot water storage period T, and the required time α. The amount of heat stored by the stable operation of the heat pump heat source device 2 is represented by a straight line L1, and the slope of the straight line L1 corresponds to the calculated output P.

  If the calculated output P is smaller than the lower limit output, the heat pump heat source machine 2 is not operated and waits until the next output calculation. When the calculation output P is larger than the upper limit output, the operation of the heat pump heat source apparatus 2 is started at the upper limit output. When the calculated output P is equal to or higher than the lower limit output and lower than the upper limit output, the operation of the heat pump heat source apparatus 2 is started with the calculated output P. Therefore, the COP can be improved by operating the heat pump heat source device 2 at a lower output than the upper limit output during hot water storage, and the energy saving performance of the hot water storage hot water supply device 1 can be improved.

  Moreover, since the hot water storage period T becomes longer due to the low output operation of the heat pump heat source unit 2, the heat dissipation loss increases. Taking this heat dissipation loss into consideration, hot water is stored by calculating the calculated output P corresponding to the slope of the straight line L2 by adding the heat dissipation loss amount H in the hot water storage period T to the predicted heat amount B. At this time, the amount of heat actually stored is represented by a straight line L1, and the predicted amount of heat B can be reliably stored by the predicted hot water supply time t1 to avoid running out of hot water during use of the hot water supply. In addition, since the operation of the heat pump heat source device 2 is calculated every predetermined period and the operation is started, there are many opportunities for hot water storage to be performed at a low output close to the lower limit output, so that the energy saving performance of the hot water storage hot water supply device 1 can be improved. . Independently of the hot water supply usage prediction, the output calculation can be performed every minute for a predetermined period, for example, so as not to miss the opportunity of operation with as low an output as possible.

  In addition, those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention, and the present invention includes such modifications.

1: Hot water storage hot water supply device 2: Heat pump heat source machine 5: Hot water storage tanks 5a to 5e: Hot water storage temperature sensor 7: Control unit 16: Hot water supply passage 21: Circulation heating circuit 21c: Temperature sensor 22: Circulation pump 32: Compressor 33: Condensation heat Exchanger 34: Expansion valve 35: Evaporative heat exchanger 35a: Outside air temperature sensor 35b: Blower 36: Refrigerant circuit 37: Heat pump control unit

Claims (3)

A hot water storage tank, a heat pump heat source machine, an auxiliary heat source machine, and predicting future hot water use based on the history of hot water use, and operating the heat pump heat source machine to correspond to the predicted hot water usage before the hot water forecast time In a hot water storage and hot water supply apparatus comprising control means for controlling the predicted amount of heat so as to store hot water in the hot water storage tank,
The output of the heat pump heat source machine can be adjusted within an output range between a predetermined upper limit output and a lower limit output,
The control means calculates the output of the heat pump heat source when performing hot water storage of the predicted heat amount in the time from the current time to the predicted hot water supply time, and waits if the calculated output is smaller than the lower limit output, If the calculated output is within the output range, start the operation of the heat pump heat source unit with the calculated output. If the calculated output is greater than the upper limit output, start the operation of the heat pump heat source unit with the upper limit output. A hot water storage and hot water supply device characterized by:   2. The hot water storage hot water supply apparatus according to claim 1, wherein the control unit adds a heat radiation loss in a time from the current time to the predicted hot water supply time to the predicted heat quantity.   The hot water storage and hot water supply apparatus according to claim 1 or 2, wherein the control means calculates the output of the heat pump heat source unit every predetermined period.