JP6604165B2 - Heat pump type water heater - Google Patents

Description

  The present invention relates to a heat pump type hot water supply apparatus capable of suitably performing hot water supply to a bathtub.

As a heat pump type hot water supply device, a hot water storage tank is combined with a heat pump that is connected to the hot water storage tank via a hot water circulation path and that allows the hot water sent from the hot water storage tank to be heated and returned to the hot water storage tank. In addition to general hot water supply, there is a hot water supply to a bathtub that is made possible (see, for example, Patent Documents 1 to 3).
Here, the hot water supply to the bathtub consumes a large amount of hot water, and after the hot water is filled, the shower is used in the bathroom. There are many cases. Therefore, when the hot water storage tank is downsized, simply filling the amount of heat stored in the hot water storage tank in advance cannot cope with the consumption of the hot water, and the heat pump needs to be restarted. However, when the amount of heat stored in the hot water storage tank is full and there is no so-called vacancy, it is substantially difficult to heat the hot water in the hot water storage tank further using a heat pump.
Therefore, in the past, as a comparatively simple method to cope with such a situation, after the hot water supply to the bathtub is started, the amount of the hot water reaches a predetermined amount, and the hot water storage tank has an appropriate space. There is a method of starting the operation of the heat pump when this occurs.

  However, in the past, there was room for improvement as described below.

  That is, conventionally, when performing hot water supply to a bathtub, the hot water supply flow rate (flow rate per unit time) to the bathtub is constant during the period from the start to the end of the hot water supply. It is a fact. For this reason, when the hot water supply flow rate to the bathtub is not so large, the time until the hot water supply amount to the bathtub reaches a predetermined amount after the hot water supply is started becomes longer, and the operation start timing of the heat pump is delayed. In this case, there is a possibility that the operation time of the heat pump cannot be extended although a lot of hot water is scheduled to be consumed thereafter. Since the heat pump has a relatively large start-up loss, it is desirable that the operation time be as long as possible as long as this heat pump is operated. However, if the heat pump operation start time is delayed, the energy efficiency of the entire hot water supply apparatus is increased accordingly. Becomes lower.

  As means for solving this, it is conceivable to increase the flow rate of hot water supplied to the bathtub and shorten the time until the amount of hot water supplied to the bathtub reaches a predetermined amount. However, when such a means is adopted, although the heat pump operation starts early, the consumption rate of the hot water in the hot water storage tank is fast, so the hot water heating by the heat pump cannot catch up with the consumption, and the hot water storage There is a problem that hot water in the tank is likely to occur early. Such a problem becomes more prominent as the capacity of the hot water storage tank is smaller.

Patent Documents 2 and 3 describe means for heating hot water using an auxiliary heat source device when hot water runs out in the hot water storage tank, and enabling continuous hot water supply to the hot water supply destination. .
However, the auxiliary heat source machine is configured to perform heat exchange between a combustion gas obtained by burning fuel gas and hot water using a heat exchanger and perform hot water heating, for example. The secondary energy efficiency (ratio of the secondary energy amount obtained from the original primary energy amount) is inferior. Therefore, when the auxiliary heat source unit is used, it is possible to cope with hot water in the hot water storage tank, but as described above, the start timing of the heat pump is delayed when hot water is supplied to the bathtub, or the hot water storage tank Due to the fact that hot water runs out easily, the operation time of the auxiliary heat source unit becomes long, and there is a problem that the energy efficiency of the entire hot water supply device is lowered.

JP 2011-52854 A JP 2014-89011 A JP 2014-70845 A

  The present invention has been conceived under the circumstances as described above, and to provide a heat pump type hot water supply device capable of performing hot water supply to a bathtub in an energy efficient and appropriate manner. That is the issue.

  In order to solve the above problems, the present invention takes the following technical means.

A heat pump type hot water supply apparatus provided by the present invention includes a hot water storage tank capable of hot water supply to a bathtub, and hot water connected to the hot water storage tank via a hot water circulation path and sent from the hot water storage tank. A heat pump that enables the operation of heating and returning the hot water to the hot water storage tank, and after the hot water supply to the bathtub is started, the operation of the heat pump is started when the hot water supply amount reaches a first predetermined amount A heat pump type hot water supply apparatus comprising: a control means; from the start of hot water supply to the bathtub until the hot water supply amount reaches the first predetermined amount or to the first predetermined amount. Hot water supply flow rate from the hot water storage tank to the bathtub (flow rate per unit time) during the first period until the second predetermined amount set in advance as a close value is reached than during the second period thereafter. There are many It is characterized by being configured to be.
In this invention, when hot water runs out in the said hot water storage tank, it can be set as the structure further equipped with the auxiliary heat source machine which can heat the hot water supplied to the said bathtub.

According to such a configuration, the following effects can be obtained.
That is, during the first period at the beginning of hot water supply to the bathtub, since the hot water flow rate from the hot water storage tank to the bathtub is large, the time until the hot water supply amount (integrated hot water supply amount) reaches the first predetermined amount is short. Become. Therefore, the operation of the heat pump is started at an early stage, and the operation time of the heat pump is lengthened by that amount, and the energy efficiency of the entire apparatus can be improved. On the other hand, during the second period thereafter, since the hot water flow rate is reduced, the rate of decrease in the amount of stored heat in the hot water storage tank becomes slow, and the phenomenon that the hot water heating by the heat pump cannot keep up with the consumption of hot water is suppressed, It is possible to prevent the hot water in the hot water storage tank from running out early. In addition, if the hot water in the hot water storage tank is prevented from running out early in this way, when the auxiliary heat source device is used to cope with hot water in the hot water storage tank, the operation time of the auxiliary heat source device should be shortened. Thus, it is possible to improve the energy efficiency of the entire apparatus.

  In the present invention, preferably, the hot water supply pipe connected to the hot water storage tank is provided with an overflow prevention valve capable of restricting a hot water supply flow rate to a general hot water supply destination different from the bathtub and the bathtub. In this overflow prevention valve, the valve opening during the first period is larger than the valve opening during general hot water supply set during hot water supply to the general hot water supply destination, and the second period. The valve opening inside is configured to be smaller than the valve opening during general hot water supply.

According to such a configuration, it is possible to increase the difference in hot water flow rate in each of the first and second periods, shorten the first period, start the heat pump early, and It is possible to increase the effectiveness of extending the operation time of the heat pump by lengthening the period 2 to make it difficult for hot water in the hot water storage tank to run out early. Further, the overflow prevention valve is originally provided in the heat pump hot water supply apparatus, and since this overflow prevention valve is utilized, its configuration is reasonable.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

It is explanatory drawing which shows an example of the heat pump type hot-water supply apparatus which concerns on this invention. It is a flowchart which shows the example of the operation control performed in the heat pump type hot-water supply apparatus of FIG.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  The heat pump hot water supply device WH shown in FIG. 1 includes a heat pump H and a hot water storage tank unit U.

The heat pump H includes a refrigeration cycle 1 similar to that conventionally known. The refrigeration cycle 1 includes, for example, an evaporative heat exchanger 10 for absorbing heat from the outside air (atmosphere), a compressor 11, and a heat exchanger 12 for heating hot water (condensation heat) on a circulation flow path of a refrigerant such as CO _2. An exchanger) and an expansion valve 13 are provided.

  The hot water storage tank unit U is provided in the forward and backward piping portions 3a and 3b and the outward piping portion 3b that constitute the hot water circulation path 3 that connects the hot water storage tank 2, the heat exchanger 12 of the heat pump H, and the hot water storage tank 2. A circulation pump P, a main control unit 4 to which a remote controller 40 is connected, and an auxiliary heat source unit 8.

  Hot water replenishment from the outside to the hot water storage tank 2 is performed through a water inlet pipe 50 connected to the lower part of the hot water storage tank 2. The end of the incoming water pipe 50 is a water inlet 50 a to which the water supply pipe 90 is connected, and for example, tap water sent from the water supply pipe 90 flows into the hot water storage tank 2. The boiling of hot water in the hot water storage tank 2 is performed after the hot water in the lower region in the hot water storage tank 2 is sent to the hot water heating heat exchanger 12 through the hot water circulation path 3 by driving the circulation pump P. This is performed in such a manner that it is returned to the upper part in the hot water storage tank 2. Therefore, the hot water heated using the heat pump H is stored sequentially from the upper side to the lower side of the hot water storage tank 2. The hot water storage tank 2 is provided with a plurality of temperature sensors Sa for detecting the internal hot water temperature at appropriate intervals in the vertical direction, and based on the temperature distribution of the hot water in the hot water storage tank 2, the main controller 4 can determine the amount of heat stored in the hot water storage tank 2 and its change.

  Hot water is discharged from the hot water storage tank 2 through a hot water supply pipe 51 connected to the upper part of the hot water storage tank 2. For example, a hot water tap 91 and a bathtub 92 are piped to the hot water outlet 51 a at the end of the hot water piping 51 and the hot water outlet 52 a of the pipe 52 branched and connected to the hot water piping 51. General hot water supply and hot water supply to the bathtub 92 by opening the on-off valve V3 are possible. Although illustration explanation is omitted, it is also possible to branch-connect a piping that enables hot water supply to the hot water heating terminal to the hot water piping 51.

The auxiliary heat source device 8 heats hot water to be hot water supplied when hot water runs out in the hot water storage tank 2 and can continue appropriate hot water supply to the hot water supply destination. If such an auxiliary heat source device 8 is provided, it is possible to use a hot water storage tank 2 having a relatively small capacity. The auxiliary heat source unit 8 is a combustion type heat source unit having a burner 80 for burning fuel gas and a heat exchanger 81 for heating hot water using the combustion gas generated by the burner 80. The hot water discharge pipe 51 is provided with an excessive outflow prevention valve V1 and a mixing valve V2. The overflow prevention valve V1 is for restricting the hot water flow rate to prevent the hot water flow rate from the hot water storage tank 2 from becoming excessive because the hot water flow rate from the hot water storage tank 2 depends on the water pressure of the water supply pipe 90. It is. The mixing valve V <b> 2 is for controlling the amount of hot water mixed in the hot water outlet pipe 51 from the branch pipe 53 branchedly connected to the incoming water pipe 50.

  The main control unit 4 cooperates with the auxiliary control unit 4A provided in the heat pump H to execute operation control of each part of the heat pump type hot water supply device WH and various data processing controls. It corresponds to an example of means. The main control unit 4 has a learning ability based on past heat demand, predicts future heat demand generation time and heat demand amount, and boiles hot water with a heat amount corresponding to the predicted heat demand in advance. The operation of storing (heat storage) in the hot water storage tank 2 is controlled. Further, the main control unit 4 is configured to execute control as described later when hot water is supplied to the bathtub 92.

  Next, an example of the operation of the heat pump type hot water supply apparatus WH and an operation processing procedure executed by the main control unit 4 will be described with reference to the flowchart of FIG.

  First, when hot water supply to the bathtub 92 is executed, hot water corresponding to the hot water supply and the amount of heat used within a predetermined time thereafter are boiled up and stored in the hot water storage tank 2. It is in the state. In such a state, when the hot water supply to the bathtub 92 is started, the valve opening of the overflow prevention valve V1 is made larger than the valve opening set at the time of general hot water supply (S1: YES, S2). Therefore, the hot water supply flow rate at the beginning of the hot water supply is increased.

  When hot water supply to the bathtub 92 is started and the amount of hot water supplied reaches the first predetermined amount, the operation of the heat pump H is started at that time (S3: YES, S4). The first predetermined amount is, for example, 10 L, but is not limited to this. The period from the start of hot water supply until the hot water supply amount reaches the first predetermined amount corresponds to an example of the first period in the present invention. During this period, as described above, the hot water supply flow rate is increased, and the amount of hot water supplied from the hot water storage tank 2 to the bathtub 92 increases rapidly. Therefore, the first period is shortened, and the operation of the heat pump H is accelerated. Be started. Therefore, the operation time of the heat pump H can be increased accordingly. In the heat pump hot water supply device WH of the present embodiment, as a basic control method of the heat pump H when hot water is supplied to the bathtub 92, when the amount of hot water supplied to the bathtub 92 reaches a first predetermined amount. A method of starting operation is adopted, and this method is utilized as it is.

  At the same time as the operation start timing of the heat pump H, the valve opening degree of the overflow prevention valve V1 is made smaller than the valve opening degree set at the time of general hot water supply, and the hot water supply flow rate is made small (S5). Such a period after the switching time of the valve opening corresponds to an example of a second period in the present invention. Thereafter, when hot water runs out in the hot water storage tank 2, the auxiliary heat source unit 8 is driven, and the low temperature hot water discharged from the hot water storage tank 2 is heated by the auxiliary heat source unit 8 and then supplied to the bathtub 92 (S6). : YES, S7). Thereafter, when the hot water filling to the bathtub 92 is completed, the driving of the auxiliary heat source unit 8 is stopped (S8: YES, S9). Further, the operation of the heat pump H is stopped when the amount of heat stored in the hot water storage tank 2 reaches a required amount in the future (S10: YES, S11).

According to such operation control, after the operation of the heat pump H is started, the flow rate of hot water supplied to the bathtub 92 is reduced, so that the rate of decrease in high-temperature hot water in the hot water storage tank 2 is reduced. For this reason, hot water shortage in the hot water storage tank 2 is prevented from occurring at an early stage. As a result, the operation time of the heat pump H can be increased while delaying the timing at which the driving of the auxiliary heat source unit 8 is started. In order to increase the overall energy efficiency of the heat pump hot water supply device WH, it is desired to operate the heat pump H for a long time so that the driving time of the auxiliary heat source unit 8 is as short as possible. To meet such demands. Further, as described above, in this embodiment, since the operation start timing of the heat pump H can be advanced, the heat pump H can be used more effectively and the overall energy efficiency can be increased.

  When the hot water storage tank 2 has a large capacity, hot water may not run out. In this case, the auxiliary heat source unit 8 is not driven, and the amount of heat stored in the hot water storage tank 2 is not increased. Is stopped at the time when the required amount is reached (S6: NO, S12: YES, S10: YES, S11).

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the heat pump hot water supply apparatus according to the present invention can be variously modified within the range intended by the present invention.

In the embodiment described above, the timing at which the valve opening degree of the overflow prevention valve V1 is switched from the larger opening degree to the smaller opening degree is such that the amount of hot water supplied from the hot water storage tank 2 to the bathtub 92 has reached the first predetermined amount. This is preferable because it coincides with the operation start time of the heat pump H. However, the present invention is not limited to this.
In the present invention, when the hot water supply amount that triggers the operation of the heat pump H reaches a second predetermined amount that is set in advance as a value close to the first predetermined amount, instead of the first predetermined amount. Thus, the valve opening degree of the excessive outflow prevention valve V1 may be switched. As a specific example, for example, when the first predetermined amount is 10L, a value such as 9L or 11L close to this can be set as the second predetermined amount. According to such a configuration, although there is a slight time difference between the operation start timing of the heat pump H and the switching timing of the valve opening degree of the overflow prevention valve V1, the effect intended by the present invention is appropriately obtained. It is possible.
The means for changing the hot water supply flow rate from the hot water storage tank 2 to the bathtub 92 is not necessarily limited to the overflow prevention valve V1, and for example, a flow rate adjustment valve is provided in the bathtub piping (pipe 52 in FIG. 1), and this flow rate adjustment is performed. You may make it change the hot_water | molten_metal supply flow volume using a valve.

WH Heat pump type hot water supply device H Heat pump U Hot water storage tank unit P Circulation pump V1 Overflow prevention valve 2 Hot water storage tank 3 Hot water circulation path 4 Main control section (control means)
8 Auxiliary heat source 51 Piping for hot water 92 Bathtub

Claims (3)

A hot water storage tank capable of filling the bathtub with hot water,
A heat pump connected to the hot water storage tank via a hot water circulation path and capable of heating the hot water sent from the hot water storage tank and returning it to the hot water storage tank;
Control means for starting operation of the heat pump when the hot water supply amount reaches a first predetermined amount after the start of hot water supply to the bathtub,
A heat pump type hot water supply device comprising:
From the start of hot water supply to the bathtub until the hot water supply amount reaches the first predetermined amount, or until a second predetermined amount preset as a value close to the first predetermined amount is reached. The heat pump type hot water supply apparatus is characterized in that the hot water supply flow rate from the hot water storage tank to the bathtub is increased during the period 1 as compared with the second period thereafter. The heat pump type hot water supply apparatus according to claim 1,
A heat pump type hot water supply apparatus further comprising an auxiliary heat source device capable of heating hot water supplied to the bathtub when a hot water outage occurs in the hot water storage tank. The heat pump type hot water supply apparatus according to claim 1 or 2,
The hot water supply pipe connected to the hot water storage tank is provided with an overflow prevention valve capable of restricting the hot water flow rate to the hot water supply destination different from the bathtub and the bathtub,
In this overflow prevention valve, the valve opening during the first period is larger than the valve opening during general hot water supply set during hot water supply to the general hot water supply destination, and during the second period. A heat pump type hot water supply apparatus configured such that the opening is made smaller than the valve opening during general hot water supply.

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