JP2009030910A - Water heater, and heat pump type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water heater and a heat pump type water heater capable of eliminating a loss of water, and improving comfortability. <P>SOLUTION: This heat pump type water heater 1 having a hot-water storage tank 20 and hot-water supply piping 30 supplying hot water stored in the hot-water storage tank 20 to a faucet 33 is provided with: reflux piping 37 connected between the hot-water supply piping 30 and the hot-water storage tank 20; a reflux pump 38 interposed in the reflux piping 37; and a control part 40 controlling the operation of the reflux pump 38. The control part 40 operates the reflux pump 38 to return lukewarm hot water in the hot-water supply piping 30 to the hot-water supply tank 20 through the reflux piping 37, and introduces the hot water in the hot-water storage tank 20 into the hot-water supply piping 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hot water supply device and a heat pump hot water supply device that supply hot water in a hot water storage tank to a hot water supply port such as a faucet through a hot water supply pipe.

Conventionally, a heat pump unit having a compressor, a refrigerant-to-water heat exchanger, an expansion valve, a refrigerant-to-air heat exchanger, and a refrigerant pipe that sequentially connects these devices, and heating with the above-described refrigerant-to-water heat exchanger There is known a heat pump type hot water supply device having a hot water storage tank for storing the hot water and a hot water supply unit having a hot water supply pipe for supplying hot water stored in the hot water storage tank to a hot water supply port such as a faucet (for example, Patent Document 1).
In this type of heat pump type hot water supply apparatus, when the faucet is opened, hot water is supplied from the hot water storage tank to the faucet via the hot water supply pipe, whereby hot water is obtained from the faucet.
JP 2002-243275 A

However, in the heat pump type hot water supply apparatus described above, the temperature of the hot water remaining in the hot water supply pipe gradually decreases and cools with time.
That is, when the faucet is opened again after a certain amount of time has passed since the faucet is closed, not the hot water at the desired temperature, but the cold hot water in the hot water supply pipe starts to come out of the faucet.
Therefore, when using hot water having a desired temperature, it is necessary to wait until the hot water having the desired temperature comes out, and there is a problem that the hot water is wasted if the cold hot water during that time is discarded.
In particular, when the above-described heat pump type hot water supply apparatus is used for hot water supply to a shower in a bathroom, when the user opens the faucet, there is a problem that the user suddenly bathes in cold hot water and feels uncomfortable.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a hot water supply apparatus and a heat pump hot water supply apparatus that eliminates waste of water and improves comfort.

  In order to achieve the above object, the present invention provides a hot water supply apparatus having a hot water storage tank and a hot water supply pipe for supplying hot water stored in the hot water storage tank to a hot water supply port, between the hot water supply pipe and the hot water storage tank. A recirculation pipe connected to the recirculation pipe; a recirculation pump interposed in the recirculation pipe; and a control unit that controls the operation of the recirculation pump; the control unit operating the recirculation pump; The cooled hot water is returned to the hot water storage tank through the reflux pipe, and the hot water in the hot water storage tank is introduced into the hot water supply pipe.

Here, in the hot water supply apparatus of the above invention, the control unit is configured such that when the time for cooling the hot water remaining in the hot water supply pipe has elapsed after the supply of hot water to the hot water supply is stopped, The operation may be started, and the hot water cooled in the hot water supply pipe may be returned to the hot water storage tank.
The hot water supply apparatus of the present invention further includes a first temperature sensor that detects a temperature of the hot water in the reflux pipe, and the control unit is detected by the first temperature sensor after starting the operation of the reflux pump. The operation of the reflux pump may be stopped when it is indicated that hot water in the hot water storage tank has been introduced into the reflux pipe based on temperature.
Further, the hot water supply apparatus of the present invention includes a second temperature sensor that detects a temperature of the hot water in the hot water supply pipe, and the control unit has a preset hot water temperature set as a temperature of the hot water discharged from the hot water outlet. When the hot water remaining in the hot water supply pipe is shown to have cooled based on the difference from the temperature detected by the second temperature sensor, the operation of the reflux pump is started, When the hot water of the hot water storage tank is introduced into the hot water discharge pipe based on the difference from the temperature detected by the second temperature sensor, the operation of the reflux pump is stopped. Also good.
In the hot water supply apparatus of the invention, the control unit stops the operation of the reflux pump when hot water is supplied from the hot water storage tank to the hot water supply port while the reflux pump is operating. You may do it.
Further, in the hot water supply apparatus of the above invention, as the hot water is supplied from the hot water storage tank to the hot water outlet, a water supply pipe for replenishing the hot water storage tank with water, and a flow rate sensor for detecting the flow rate of the water in the water supply path, The control unit may detect supply of hot water from the hot water storage tank to the hot water supply port based on a detection result of the flow rate sensor.

  In order to achieve the above object, the present invention provides a heat pump unit having a compressor, a refrigerant-to-water heat exchanger, an expansion valve, a refrigerant-to-air heat exchanger, and a refrigerant pipe that sequentially connects these devices. A hot water storage unit that stores hot water heated by the refrigerant-to-water heat exchanger, and a hot water supply unit that supplies hot water stored in the hot water storage tank to a hot water outlet. A reflux pipe connected between the pipe and the hot water storage tank; a reflux pump interposed in the reflux pipe; and a control unit that controls the operation of the reflux pump. The pump is operated, the hot water cooled in the hot water supply pipe is returned to the hot water storage tank through the reflux pipe, and the hot water in the hot water storage tank is introduced into the hot water supply pipe.

  According to the present invention, the cold hot water in the hot water supply pipe is returned to the hot water storage tank via the reflux pipe, and the hot water in the hot water storage tank is introduced into the hot water supply pipe, so that the cold hot water remains in the hot water supply pipe. Can be prevented. Therefore, since the user can obtain hot water that is not cooled from the beginning of hot water supply, the user does not have to wait until the hot water comes out, and the water during that time is not wasted. Furthermore, even if it is used for hot water supply in a bathroom, it is possible to improve comfort without being exposed to unexpectedly cooled hot water.

Embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>
FIG. 1 is a circuit diagram of a heat pump type hot water supply apparatus 1 according to the present embodiment.
As shown in FIG. 1, the heat pump hot water supply apparatus 1 includes a heat pump unit 2 and a hot water supply unit 3.

As shown in FIG. 1, the heat pump unit 2 includes a compressor 4, a refrigerant-to-water heat exchanger 5, an expansion valve 6, a refrigerant-to-air heat exchanger 7, and an accumulator 8. The devices are sequentially connected through the refrigerant pipe 9 to form a refrigeration cycle. CO ₂ is pressurized and sealed in the refrigerant pipe 9 as a refrigerant, and the refrigerant circulates in the refrigeration cycle in the direction indicated by the broken line arrow in the drawing according to the operation of the compressor 4.
The compressor 4 compresses the sucked refrigerant to generate a high-temperature and high-pressure refrigerant and discharges it. The refrigerant-to-water heat exchanger 5 heats water flowing in the flowing water pipe 10C by exchanging heat between the high-temperature refrigerant discharged from the compressor 4 and water flowing in the flowing water pipe 10C described later. Then, the refrigerant cooled by heat exchange is derived. The expansion valve 6 depressurizes the introduced refrigerant to generate a low-temperature and low-pressure refrigerant and derives it. The refrigerant-to-air heat exchanger 7 conducts heat exchange between the low-temperature and low-pressure refrigerant derived by the expansion valve 6 and the atmosphere, thereby raising the temperature of the refrigerant and then deriving the refrigerant. Here, a fan 11 is provided in the vicinity of the refrigerant-to-air heat exchanger 7, and the fan 11 blows air toward the refrigerant-to-air heat exchanger 7 to increase the efficiency of heat exchange. The accumulator 8 derives only the gaseous refrigerant out of the introduced refrigerant so that the compressor 4 sucks only the gaseous refrigerant.

On the other hand, the hot water supply unit 3 includes a hot water storage tank 20 for storing hot water heated by the refrigerant-to-water heat exchanger 5, as shown in FIG.
The hot water storage tank 20 is connected to the refrigerant-to-water heat exchanger 5 via the circulation path 10. The circulation path 10 includes an outward pipe 10A connecting the bottom 20C of the hot water storage tank 20 and the refrigerant-to-water heat exchanger 5, and a return pipe connecting the refrigerant-to-water heat exchanger 5 and the top 20A of the hot water storage tank 20. 10B and a flowing water pipe 10C for connecting one end of the forward pipe 10A and one end of the return pipe 10B in the refrigerant-to-water heat exchanger 5, and a circulation pump 21 is provided in the forward pipe 10A. Is provided. When this circulation pump 21 is driven, hot water stored at a temperature near the bottom 20C of the hot water storage tank 20 flows out to the flow pipe 10C in the refrigerant-to-water heat exchanger 5 through the forward pipe 10A, and flows into the water pipe. After being heated by the refrigerant heat at 10C to become hot hot water, it flows into the top 20A of the hot water storage tank 20 via the return pipe 10B and is stored again in the hot water storage tank 20. In this manner, in the hot water supply unit 3, circulation is performed in which the low-temperature hot water in the bottom portion 20 </ b> C of the hot water storage tank 20 is heated by the refrigerant-to-water heat exchanger 5 and flows into the top portion 20 </ b> A of the hot water storage tank 20. Thereby, the temperature rise of the hot water in the hot water storage tank 20 and temperature maintenance are performed.

  Inside the hot water storage tank 20, as shown in FIG. 1, a tank-side temperature sensor 22A for detecting the temperature of hot water stored near the top 20A of the hot water storage tank 20 and hot water stored near the intermediate portion 20B. A tank side temperature sensor 22B for detecting the temperature and a tank side temperature sensor 22C for detecting the temperature of the hot water stored in the vicinity of the bottom 20C are provided.

A water supply pipe 23 for supplying tap water to the hot water storage tank 20 is connected to the bottom 20 </ b> C of the hot water storage tank 20. The water supply pipe 23 is provided with a pressure reducing valve 24 and a check valve 25, and the tap water is decompressed to a predetermined pressure by the pressure reducing valve 24 and is always supplied to the hot water storage tank 20. Therefore, tap water pressure always acts in the hot water storage tank 20.
A flow rate sensor 26 is provided near the hot water storage tank 20 in the water supply pipe 23, and the flow rate of the tap water flowing through the water supply pipe 23 is detected by the flow rate sensor 26.
Here, when a user or the like opens the faucet 33 by twisting the handle of the faucet 33 (hot water outlet) or the like, and starts the hot water from the faucet 33, the hot water in the hot water storage tank 20 is supplied to the faucet 33, and accordingly The hot water storage tank 20 is replenished with tap water through the water supply pipe 23. That is, tap water flows through the water supply pipe 23 when the hot water is discharged from the tap 33. Further, the tap water does not flow in the water supply pipe 23 except for the above factors except when the hot water tank 20 is initially refilled with water. For this reason, the flow sensor 26 detects whether the hot water has been started and whether the hot water has been stopped through the detection of the flow rate of the water supply pipe 23.
In the following description, as described above, a user or the like opens the faucet 33 by twisting the handle of the faucet 33, and hot water is supplied from the hot water storage tank 20 to the faucet 33 and discharged from the faucet 33. On the contrary, when a user or the like closes the faucet 33 by twisting the handle of the faucet 33 and stops discharging the hot water from the faucet 33, this is called stoppage of the hot water.

Connected to the top 20A of the hot water storage tank 20 is a hot water supply pipe 30 for supplying hot water stored in the hot water storage tank 20 to the faucet 33 (hot water supply point) when hot water is supplied.
As shown in FIG. 1, the hot water supply pipe 30 has a first hot water supply pipe 30A and a second hot water supply pipe 30B. The first hot water supply pipe 30A has one end connected to the top 20A of the hot water storage tank and the other end connected to the mixing valve 31, and the second hot water supply pipe 30B has one end connected to the mixing valve 31 and the other end. Is connected to the faucet 33. The mixing valve 31 mixes hot water in the hot water storage tank 20 that has flowed in through the first hot water supply pipe 30A and tap water at a predetermined ratio during hot water to generate hot water having a hot water set temperature described later, The hot water supply pipe 30B flows out, and a bypass pipe 32 connected to the water supply pipe 23 is connected in addition to the first and second hot water supply pipes 30A and 30B.
When hot water is started, hot hot water near the top 20A of the hot water storage tank 20 flows into the mixing valve 31 through the first hot water supply pipe 30A, and tap water is mixed into the mixing valve 31 through the bypass pipe 32. The hot water stored in the hot water storage tank 20 and the tap water are mixed at a predetermined ratio in the mixing valve 31 to generate hot water having a hot water set temperature described later, and the generated hot water is used as the second hot water supply. The water is supplied to the faucet 33 through the pipe 30B, and the hot water from the faucet 33 is discharged.

  Further, a pressure relief pipe 39 is connected to the first hot water supply pipe 30 </ b> A in the vicinity of the hot water storage tank 20, and a pressure relief valve 19 is provided in the pressure relief pipe 39. The pressure relief valve 19 releases the pressure when the water stored in the hot water storage tank 20 is excessively heated and the pressure in the hot water storage tank 20 becomes excessive.

  By the way, in the conventional heat pump type hot water supply apparatus, when the hot water is stopped, the water that flows out from the hot water storage tank 20 toward the faucet 33 remains in the hot water supply pipe 30. Since the hot water remaining in the hot water supply pipe 30 is not heated, the temperature gradually decreases with the passage of time. When hot water is started again in this state, first, the low-temperature hot water remaining in the second hot water supply pipe 30B is supplied from the faucet. Thereafter, the low temperature hot water remaining in the first hot water supply pipe 30 </ b> A and the tap water are mixed in the mixing valve to generate hot water having a temperature lower than the desired temperature, and this low temperature hot water is supplied from the faucet 33. Conventionally, during this period, that is, until all the hot water remaining in the hot water supply pipe 30 is discharged, low-temperature hot water is discharged from the tap 33, which causes the disposal of hot water and the like. I was invited.

In view of this, the heat pump type hot water supply apparatus 1 of this embodiment has a reflux pipe 37 having one end 37A connected to the bottom 20C of the hot water storage tank 20 and the other end 37B connected to the vicinity of the faucet 33 in the hot water supply pipe 30. is doing. Then, by driving a recirculation pump 38 to be described later, the cooled hot water remaining in the hot water supply pipe 30 is returned to the bottom 20C of the hot water storage tank 20 through the recirculation pipe 37 and at the same time the top of the hot water storage tank 20 The hot hot water of 20A is introduced into the first hot water supply pipe 30 </ b> A to prevent the cold hot water from remaining in the hot water supply pipe 30.
Here, since one end 37A of the reflux pipe 37 is connected to the bottom 20C of the hot water storage tank 20, the cold hot water introduced into the hot water storage tank 20 through the reflux pipe 37 is the bottom where the low temperature hot water is stored. It flows in the vicinity of 20C. For this reason, the cold hot water introduced does not cause a temperature drop of the hot water in the hot water storage tank 20. Further, since the other end 37B of the reflux pipe 37 is connected to the vicinity of the tap 33 in the second hot water supply pipe 30B of the hot water supply pipe 30, the hot water supply pipe 30 is returned to the hot water storage tank 20 when the cold hot water in the hot water supply pipe 30 is returned. Most of the hot water remaining in the hot water can be returned to the hot water storage tank 20.
In addition, as shown in FIG. 1, the reflux pipe 37 is provided with a reflux pump 38 and a check valve 27. Under the driving of the reflux pump 38, the hot water in the hot water supply pipe 30 is returned to the hot water storage tank 20 through the reflux pipe 37, and the check valve 27 is a reverse flow in the reflux pipe 37, that is, hot water storage. This prevents the flow of hot water from the tank 20 toward the reflux pipe 37.

  The heat pump hot water supply apparatus 1 controls the tank side temperature sensors 22A, 22B, and 22C, controls the flow rate sensor 26, drives the compressor 4, drives the circulation pump 21, and controls the mixing valve 31. A control unit 40 that controls the entire heat pump hot water supply apparatus 1 through various controls such as opening control and drive control of the reflux pump 38, and a remote controller that gives various instructions to the control unit 40 (hereinafter referred to as "remote control"). 41.

FIG. 2 is a block diagram showing a functional configuration of the heat pump type hot water supply apparatus 1.
The control unit 40 includes a CPU 42 for executing various programs and arithmetic processing, a ROM 43 for storing control programs and various data executed by the CPU 42, and a work area for temporarily storing calculation results and various data of the CPU 42. And a RAM 44 functioning as The control unit 40 includes an oscillator (not shown), generates a reference clock, and based on the reference clock, measures elapsed time such as predetermined times T1 and T2, which will be described later, and various timing operations. Can be executed.
The remote controller 41 includes an operation element 45 that performs an operation based on an instruction when the user gives an instruction, and a display unit 46 that displays various information, and is connected to the control unit 40 so as to be communicable. In the heat pump type hot water supply apparatus 1 of the present embodiment, the user can set the temperature of water to be supplied from the faucet 33 at the time of hot water supply (hereinafter referred to as “hot water set temperature”) via the remote controller 41. It has a configuration. When the user operates the operation element 45 to instruct the hot water set temperature, the CPU 42 of the control unit 40 generates hot water set temperature data 47 indicating the hot water set temperature based on a signal related to the operation, and the RAM 44. To remember.

Tank-side temperature sensors 22A, 22B, and 22C provided in each part in the hot water storage tank 20 transmit a signal related to the detected temperature to the control unit 40. Based on this signal, the CPU 42 of the control unit 40 uses the top 20 A, intermediate 20 B and bottom 20 C temperatures in the hot water storage tank 20 to indicate the current temperatures in the top tank temperature data 48 A, the intermediate tank temperature data 48 B, and the bottom. Tank temperature data 48C is generated and stored in the RAM 44.
The flow rate sensor 26 provided in the water supply pipe 23 transmits a signal related to the detected flow rate to the control unit 40. The CPU 42 of the control unit 40 generates flow rate data 50 indicating the flow rate of tap water flowing through the water supply pipe 23 based on this signal, and stores it in the RAM 44. As described above, when the hot water is discharged from the tap 33, the tap water flows through the water supply pipe 23 as the hot water storage tank 20 is replenished. Therefore, the CPU 42 refers to the flow rate data 50 so that the hot water is discharged. It can be determined whether or not the hot water is started and whether or not the hot water is stopped.

If the CPU 42 refers to the tank temperature data 48A, 48B, 48C stored in the RAM 44 and determines that the temperature of the hot water in the hot water storage tank 20 has not reached the predetermined temperature, it sends a drive signal to the circulation pump 21. By feeding and driving the circulation pump 21, the water in the hot water storage tank 20 is circulated through the circulation path 10, and the temperature of the hot water in the hot water storage tank 20 is increased. At the same time, the CPU 42 sends a drive signal to the compressor 4 to increase the motion capacity of the compressor 4, increase the temperature of the refrigerant discharged from the compressor 4, and increase rate of the temperature of water in the refrigerant-to-water heat exchanger 5. To improve.
Further, the CPU 42 refers to the hot water set temperature data 47 stored in the RAM 44 and controls the opening degree of each valve of the mixing valve 31 so that the temperature of the hot water discharged from the tap 33 becomes the hot water set temperature. As a result, the hot water in the hot water storage tank 20 and the tap water supplied from the bypass pipe 32 are mixed at a rate such that the hot water setting temperature is reached, and hot water having a temperature close to the hot water setting temperature is generated.
Further, the CPU 42 sends a drive signal to the recirculation pump 38 to drive the recirculation pump 38 in order to return the cooled hot water remaining in the hot water supply pipe 30 to the hot water storage tank 20 in accordance with predetermined conditions described later.

Next, the operation of the heat pump type hot water supply apparatus 1 will be described using a flowchart.
When the hot water supply is stopped, the heat pump hot water supply apparatus 1 according to the present embodiment starts measuring the elapsed time after the hot water supply is stopped, and when a predetermined time T1 to be described later elapses, the CPU 42 of the control unit 40 supplies the hot water supply pipe. It is considered that the hot water remaining in 30 has cooled with the passage of the predetermined time T1, and the reflux pump 38 is driven to return the cold hot water in the hot water supply pipe 30 to the hot water storage tank 20 via the reflux pipe 37. The operation of introducing the hot water into the hot water supply pipe 30 is executed. Hereinafter, operation | movement of the heat pump type hot-water supply apparatus 1 is explained in full detail using FIG. The operation shown in this figure is performed by the CPU 42 executing a control program stored in the ROM 43.

The CPU 42 of the control unit 40 continuously monitors whether or not the hot water has started by referring to the flow rate data 50 stored in the RAM 44 (step SA1). When the hot water is started (step SA1: YES), the CPU 42 constantly monitors whether or not the hot water is stopped by referring to the flow rate data 50 (step SA2).
When the hot water is stopped (step SA2: YES), the CPU 42 starts measuring the elapsed time after the hot water is stopped in order to detect the elapse of a predetermined time T1 set in advance (step SA3). In the present embodiment, the predetermined time T1 is a time required for the temperature of the hot water remaining in the hot water supply pipe 30 to cool down to such an extent that the user feels cold when the hot water is discharged. Is set. In addition, when it is desired that hot water at a relatively high temperature remain in the hot water supply pipe 30 at all times, the predetermined time T1 is set short, and a state where hot water at a relatively low temperature remains in the hot water supply pipe 30 appears. If this is allowed, the predetermined time T1 is set long. Further, during the night when the use frequency of the heat pump type hot water supply apparatus 1 is low, the length of the predetermined time T1 can be changed according to the time zone, such as setting the predetermined time T1 longer.
During the elapsed time measurement, the CPU 42 refers to the flow rate data 50 to continuously monitor whether or not the hot water is started (step SA4). This is because when hot water discharge is started during the elapsed time measurement, hot hot water in the hot water storage tank 20 newly flows into the hot water supply pipe 30 to the hot water supply pipe 30, so that the measurement for the predetermined time T <b> 1 needs to be started again. Because there is. When the hot water is started (step SA4: YES), the CPU 42 returns to step SA2 and monitors whether the hot water is stopped.
When the hot water has not started (step SA4: NO), the CPU 42 determines whether or not the predetermined time T1 has elapsed since the start of the elapsed time measurement. When the predetermined time T1 has not elapsed (step SA5: NO), the CPU 42 returns to step SA4 and monitors whether the hot water has started.

On the other hand, when the predetermined time T1 has elapsed (step SA5: YES), the hot water in the hot water supply pipe 30 has cooled with the elapse of the predetermined time T1, so the CPU 42 transmits a drive signal to the reflux pump 38. The hot water in the hot water supply pipe 30 is returned to the hot water storage tank 20 through the return pipe 37 and the hot water in the hot water storage tank 20 is supplied with hot water. It introduce | transduces into the piping 30 (step SA6).
Thereafter, the CPU 42 starts measuring the elapsed time from the start of driving of the reflux pump 38 in order to detect the elapse of a predetermined time T2 set in advance (step SA7). The predetermined time T2 is a time for which the reflux pump 38 should be driven. When the reflux pump 38 is driven for the predetermined time T2, almost all of the water remaining in the hot water supply pipe 30 is returned to the hot water storage tank 20, and the hot water storage The time for hot water in the tank 20 to be introduced into the hot water supply pipe 30 is set.

  While the recirculation pump 38 is being driven, the CPU 42 refers to the flow rate data 50 to determine whether or not the hot water has started (step SA8). When the hot water is started (step SA8: YES), the CPU 42 stops driving the reflux pump 38 (step SA9), returns to step SA2, and again monitors whether the hot water is stopped (step SA2). . This is because hot water supplied from the hot water storage tank 20 to the faucet 33 when hot water is started while the recirculation pump 38 is driven is connected to the hot water storage tank 20 via the recirculation pipe 37 under the drive of the recirculation pump 38. Thus, the pressure of the water flowing from the hot water storage tank 20 to the faucet 33 is attenuated in the hot water supply pipe 30, and the water pressure of the hot water discharged from the faucet 33 is attenuated. This is to prevent this by interrupting the driving of the reflux pump 38.

  If the hot water has not started in step SA8, the CPU 42 determines whether or not the predetermined time T2 has elapsed since the reflux pump 38 was driven (step SA10). When the predetermined time T2 has not elapsed (step SA10: NO), the CPU 42 returns to step SA8 and monitors whether the hot water has started. On the other hand, when the predetermined time T2 has elapsed (step SA10: YES), almost all of the cooled hot water remaining in the hot water supply pipe 30 is returned to the hot water storage tank 20 by driving the reflux pump 38 for the predetermined time T2. Since the hot water in the hot water storage tank 20 can be regarded as having been introduced into the hot water supply pipe 30, the CPU 42 stops driving the reflux pump 38 (step SA11), returns to step SA1, and whether or not the hot water is started. To monitor.

  As described above, according to the present embodiment, the heat pump type hot water supply apparatus 1 includes the recirculation pipe 37 connected between the hot water supply pipe 30 and the hot water storage tank 20 and the recirculation pump interposed in the recirculation pipe 37. 38 and a control unit 40 that controls the operation of the reflux pump 38, and this control unit 40 operates the reflux pump 38, and cools hot and cold water in the hot water supply pipe 30 through the reflux pipe 37. Since the hot water in the hot water storage tank 20 is introduced into the hot water supply pipe 30, it is possible to prevent the cooled hot water from remaining in the hot water supply pipe. Therefore, since the user can obtain hot water that is not cooled from the beginning of hot water supply, the user does not have to wait until the hot water comes out, and the water during that time is not wasted. Furthermore, even if it is used for hot water supply in a bathroom, it is possible to improve comfort without being exposed to unexpectedly cooled hot water.

  Further, in the present embodiment, after the supply of hot water to the faucet 33 is stopped, the control unit 40 drives the reflux pump 38 when a predetermined time T1 has passed so that the hot water remaining in the hot water supply pipe 30 is cooled. The cold hot water in the hot water supply pipe 30 is returned to the hot water storage tank 20. For this reason, it is possible to automatically drive the reflux pump 38 at an appropriate timing, and to reliably prevent the hot water contained in the hot water supply pipe 30 from remaining.

  In the present embodiment, when the control unit 40 determines that hot water is supplied from the hot water storage tank 20 to the faucet 33 while the reflux pump 38 is being driven, the control unit 40 stops driving the reflux pump 38. For this reason, as described above, even when the hot water is started during the driving of the reflux pump 38, the reflux pipe 37 is connected to the hot water supplied from the hot water storage tank 20 to the faucet 33 under the driving of the reflux pump 38. Therefore, the pressure of the water discharged from the tap 33 is not attenuated by applying a force to return to the hot water storage tank 20.

  In the present embodiment, the control unit 40 refers to the flow rate data 50 stored in the RAM 44 to determine whether hot water has been supplied from the hot water storage tank 20 to the faucet 33. Here, if the flow rate sensor 26 is provided in the hot water supply pipe 30, hot water flows through the hot water supply pipe 30 due to the driving of the reflux pump 38 during the driving of the reflux pump 38. Even if the hot water is started, the flow sensor 26 and the control unit 40 cannot recognize that the hot water has been started. In this regard, in this embodiment, the flow rate sensor 26 is provided in the water supply pipe 23, and depending on whether or not the hot water storage tank 20 is replenished with water through the water supply pipe 23, the flow rate sensor 26 is connected to the faucet 33. Since it is determined whether or not hot water has been supplied, the supply can be reliably detected without being affected by the driving of the reflux pump 38.

Second Embodiment
Next, a second embodiment will be described.
FIG. 4 is a circuit diagram of the heat pump hot water supply apparatus 60 according to the present embodiment. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
In this embodiment, as shown in FIG. 4, the return pipe side temperature sensor 28 (first temperature sensor) is provided in the return pipe 37, and the temperature of the hot water flowing through the return pipe 37 is determined by the return pipe side temperature sensor 28. Can be detected. This configuration is different from the first embodiment.

FIG. 5 is a block diagram showing a functional configuration of the heat pump hot water supply apparatus 60 according to the present embodiment.
The recirculation pipe side temperature sensor 28 transmits a signal related to the detected temperature to the control unit 40. Based on this signal, the CPU 42 of the control unit 40 generates return pipe temperature data 51 indicating the current temperature of hot water in the return pipe 37 and stores it in the RAM 44.

  Next, the operation of the heat pump type hot water supply apparatus 60 will be described using a flowchart. In the first embodiment, after the driving of the reflux pump 38 is started, it is determined whether or not the predetermined time T2 has elapsed, and when the predetermined time T2 has elapsed, the driving of the reflux pump 38 is stopped. On the other hand, in the present embodiment, after the driving of the reflux pump is started, when the temperature of the hot water flowing through the reflux pipe 37 becomes equal to or higher than a predetermined temperature D1, which will be described later, the cold hot water in the hot water supply pipe 30 is returned to the hot water storage tank 20. The hot water storage tank 20 is regarded as having been introduced into the hot water supply pipe 30, and the driving of the reflux pump is stopped. Hereinafter, operation | movement of the heat pump type hot-water supply apparatus 60 is explained in full detail using FIG. The operation shown in this figure is performed by the CPU 42 executing a control program stored in the ROM 43.

As shown with the same reference numerals in FIG. 6, the process up to step SA6, that is, the process until the driving of the reflux pump 38 is started is performed in the same procedure as in the first embodiment.
After starting the driving of the reflux pump 38 (step SA6), the CPU 42 refers to the flow rate data 50 without starting the measurement of the elapsed time from the start of the driving of the reflux pump 38. Is determined (step SA8). When the hot water is started (step SA8: YES), the CPU 42 stops driving the reflux pump 38 (step SA9), returns to step SA2, and monitors whether the hot water is stopped (step SA2).
On the other hand, when the hot water has not started (step SA8: NO), the CPU 42 refers to the reflux pipe temperature data 51 stored in the RAM 44, and the temperature of the hot water flowing through the reflux pipe 37 is equal to or higher than a predetermined temperature D1. Is determined (step SB1). Here, the predetermined temperature D1 is a temperature at which it can be confirmed that hot water in the hot water storage tank 20 has been introduced into the reflux pipe 37, and the temperature of the hot water in the reflux pipe 37 exceeds the predetermined temperature D1. Thus, it can be considered that the hot water cooled in the hot water supply pipe 30 has been returned to the hot water storage tank 20 and the hot water storage tank 20 has been introduced into the hot water supply pipe 30.
When the hot water in the reflux pipe 37 has not reached the predetermined temperature D1 (step SB1: NO), the CPU 42 returns to step SA8 and determines whether or not the hot water is started. On the other hand, when the hot water in the reflux pipe 37 is equal to or higher than the predetermined temperature D1 (step SB1: YES), the hot water in the hot water supply pipe 30 can be regarded as being sufficiently high, and the CPU 42 stops driving the reflux pump 38. (Step SB2), the process returns to Step SA1 again to monitor whether hot water supply is started again.

  As described above, in the present embodiment, the return pipe side temperature sensor 28 is provided in the return pipe 37, and the controller 40 detects the temperature of the hot water in the return pipe 37 detected by the return pipe side temperature sensor 28. However, when the temperature becomes equal to or higher than the predetermined temperature D1, the operation of the reflux pump 38 is stopped. For this reason, the reflux pump 38 can be driven only while it is necessary for the hot water in the hot water supply pipe 30 to reach an appropriate temperature.

<Third Embodiment>
Next, a third embodiment will be described.
FIG. 7 is a circuit diagram of the heat pump type hot water supply apparatus 70 according to the present embodiment. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
In this embodiment, as shown in FIG. 7, a hot water supply pipe side temperature sensor 29 (second temperature sensor) is provided in the second hot water supply pipe 30 </ b> B of the hot water supply pipe 30. The temperature of the hot water flowing through the pipe 30 can be detected. This configuration is different from the first embodiment.

FIG. 8 is a block diagram showing a functional configuration of the heat pump hot water supply apparatus 70 according to the present embodiment.
The hot water supply pipe side temperature sensor 29 transmits a signal related to the detected temperature to the control unit 40. Based on this signal, the CPU 42 of the control unit 40 generates hot water supply pipe temperature data 52 indicating the current temperature of hot water in the hot water supply pipe 30 and stores it in the RAM 44.

  Next, the operation of the heat pump type hot water supply apparatus 70 will be described using a flowchart. In the first embodiment, after the hot water is stopped, when the predetermined time T1 has elapsed, the driving of the reflux pump 38 is started, and when the predetermined time T2 has elapsed, the driving of the reflux pump is stopped. On the other hand, in the present embodiment, when the difference between the hot water set temperature set by the user and the temperature of the hot water in the hot water supply pipe 30 becomes equal to or higher than a predetermined temperature D2 described later, the hot water remaining in the hot water supply pipe 30 is reduced. It is considered that the cooling has been cooled, and the driving of the reflux pump is started. When this difference becomes equal to or lower than the predetermined temperature D3, it is considered that hot water in the hot water storage tank 20 has been introduced into the hot water supply pipe 30, and the driving of the reflux pump 38 is stopped. . Hereinafter, operation | movement of the heat pump type hot-water supply apparatus 70 is explained in full detail using FIG. The operation shown in this figure is performed by the CPU 42 executing a control program stored in the ROM 43.

The CPU 42 acquires the hot water set temperature data 47 and the hot water supply pipe temperature data 52 stored in the RAM 44, and determines whether or not the difference between the hot water set temperature and the temperature of the hot water in the hot water supply pipe 30 is equal to or higher than a predetermined temperature D2. Judgment is made (step SC1). Here, in the present embodiment, the predetermined temperature D2 is defined as the set temperature of hot water and the temperature of hot water in the hot water supply pipe 30 such that the user feels cold when the hot water in the hot water supply pipe 30 is discharged. It is a difference, and when the difference between the hot water set temperature and the temperature of the hot water in the hot water supply pipe 30 exceeds the predetermined temperature D2, it can be considered that the hot water in the hot water supply pipe 30 is sufficiently cooled. In addition, when it is desired that hot water at a relatively high temperature remains in the hot water supply pipe 30 at all times, the predetermined temperature D2 is set low, and a state in which hot water at a relatively low temperature remains in the hot water supply pipe 30 appears. If this is allowed, the predetermined temperature D2 is set large. In addition, during the night when the use frequency of the heat pump hot water supply device 1 is low, the predetermined temperature D2 can be changed according to the time zone, for example, by setting the predetermined temperature D2 high.
When the difference between the hot water set temperature and the temperature of hot water in the hot water supply pipe 30 is equal to or higher than the predetermined temperature D2 (step SC1: YES), the CPU 42 transmits a drive signal to the circulation pump 21 to drive it.

While the recirculation pump 38 is being driven, the CPU 42 monitors whether or not the hot water is started with reference to the flow rate data 50 (step SC3) as in the first embodiment, and when the hot water is started (step SC3: YES), the driving of the reflux pump is stopped (step SC4), and the process returns to step SC1.
On the other hand, when the hot water has not started (step SC3: NO), the CPU 42 acquires the hot water set temperature data 47 and the hot water supply pipe temperature data 52 stored in the RAM 44, and the hot water set temperature and the hot water supply pipe 30 are obtained. It is determined whether or not the difference between the hot and cold water is within a predetermined temperature D3 (step SC5). Here, the predetermined temperature D3 is set so that the user does not feel cold when the hot water in the hot water storage tank 20 is introduced into the recirculation pipe 37 and the hot water is discharged as a result of driving the recirculation pump. This is the difference between the hot water set temperature that can be considered that the temperature and the temperature of the hot water in the hot water supply pipe 30 are close to each other, and the temperature of the hot water in the hot water supply pipe 30. When the difference between the hot water set temperature and the temperature of the hot water in the hot water supply pipe 30 is within the predetermined temperature D3, the hot water cooled in the hot water supply pipe 30 is returned to the hot water storage tank 20, and the hot water in the hot water storage tank 20 is supplied to the hot water supply pipe. It can be considered that it was introduced at 30.
When the difference between the hot water set temperature and the temperature of the hot water in the hot water supply pipe 30 is greater than the predetermined temperature D3 (step SC5: NO), the CPU 42 returns to step SC3 and monitors whether the hot water has started. When the difference between the hot water set temperature and the temperature of hot water in the hot water supply pipe 30 is equal to or lower than the predetermined temperature D3 (step SC5: YES), the hot water set temperature is set to such an extent that the user does not feel cold when the hot water is discharged. Since the temperature of the hot water in the hot water supply pipe 30 is sufficiently close, the CPU 42 stops driving the recirculation pump 38 (step SC4), returns to step SC1, and again returns to the hot water set temperature data stored in the RAM 44. 47 and hot water supply pipe temperature data 52 are acquired, and it is determined whether or not the difference between the hot water set temperature and the temperature of the hot water in the hot water supply pipe 30 is equal to or higher than a predetermined temperature D2 (step SC1).

  As described above, in the present embodiment, the hot water supply pipe side temperature sensor 29 is provided in the hot water supply pipe 30, and the CPU 42 of the control unit 40 is configured as the temperature of the hot water discharged from the faucet 33. When the difference between the set temperature and the temperature detected by the hot water supply pipe side temperature sensor 29 becomes equal to or higher than the predetermined temperature D2, the driving of the reflux pump 38 is started, and the hot and cold water in the hot water supply pipe 30 is cooled. When the temperature of the hot water set temperature and the temperature detected by the hot water supply pipe side temperature sensor 29 becomes equal to or lower than the predetermined temperature D3, the driving of the reflux pump 38 is stopped. For this reason, it is possible to prevent the hot water in the hot water supply pipe 30 from being lowered to the extent that the user feels cold at the time of hot water supply, and hot water close to a desired temperature can be discharged immediately after the start of hot water supply.

In addition, embodiment mentioned above shows the one aspect | mode of this invention to the last, and a deformation | transformation and application are arbitrarily possible within the scope of the present invention.
For example, in the first and second embodiments, the present invention has been described by taking the heat pump type hot water supply device 1 as an example. However, the present invention is not limited to the heat pump type hot water supply device 1 but also a hot water storage tank and a hot water supply device. The present invention can be widely applied to a hot water supply apparatus including a hot water discharge pipe that flows out from a hot water storage tank.
Further, in the second embodiment, the driving of the reflux pump 39 is stopped when the temperature detected by the reflux pipe side temperature sensor 28 becomes equal to or higher than the predetermined temperature D1 during the driving of the reflux pump 38. The location where the temperature sensor is provided is not limited to the reflux pipe, and may be provided in the hot water supply pipe as in the third embodiment.
Further, an open / close valve may be provided in the hot water supply pipe 30 so that the open / close valve is closed while the reflux pump 38 is driven so that hot water is not supplied.

It is a circuit diagram of the heat pump type hot-water supply apparatus which concerns on 1st Embodiment. It is a block diagram which shows the functional structure of a heat pump type hot-water supply apparatus. It is a flowchart which shows operation | movement of a heat pump type hot-water supply apparatus. It is a circuit diagram of the heat pump type hot-water supply apparatus which concerns on 2nd Embodiment. It is a block diagram which shows the functional structure of a heat pump type hot-water supply apparatus. It is a flowchart which shows operation | movement of a heat pump type hot-water supply apparatus. It is a circuit diagram of the heat pump type hot-water supply apparatus which concerns on 3rd Embodiment. It is a block diagram which shows the functional structure of a heat pump type hot-water supply apparatus. It is a flowchart which shows operation | movement of a heat pump type hot-water supply apparatus.

Explanation of symbols

1, 60, 70 Heat pump hot water supply device 2 Heat pump unit 3 Hot water supply unit 4 Compressor 5 Refrigerant to water heat exchanger 6 Expansion valve 7 Refrigerant to air heat exchanger 8 Accumulator 9 Refrigerant piping 20 Hot water storage tank 23 Water supply pipe 26 Flow rate sensor 28 Return pipe side temperature sensor (first temperature sensor)
29 Hot water supply pipe side temperature sensor (second temperature sensor)
30 Hot water supply piping 33 Faucet (hot water supply port)
37 Reflux piping 38 Reflux pump 40 Control unit

Claims (7)

In a hot water supply apparatus having a hot water storage tank and a hot water supply pipe for supplying hot water stored in the hot water storage tank to a hot water outlet,
A reflux pipe connected between the hot water supply pipe and the hot water storage tank, a reflux pump interposed in the reflux pipe, and a control unit for controlling the operation of the reflux pump;
The control unit operates the reflux pump, returns the hot water cooled in the hot water supply pipe to the hot water storage tank through the reflux pipe, and introduces the hot water in the hot water storage tank into the hot water supply pipe. Hot water supply device. The controller is
When the time for cooling the hot water remaining in the hot water supply pipe has elapsed after the supply of hot water to the hot water supply is stopped, the operation of the reflux pump is started, and the cold hot water in the hot water supply pipe is It returns to a hot water storage tank. The hot water supply apparatus of Claim 1 characterized by the above-mentioned. A first temperature sensor for detecting a temperature of hot water in the reflux pipe;
The controller, after starting the operation of the reflux pump, when it is indicated that the hot water in the hot water storage tank has been introduced into the reflux pipe based on the temperature detected by the first temperature sensor, The hot water supply device according to claim 1 or 2, wherein the operation of the reflux pump is stopped. A second temperature sensor for detecting the temperature of the hot water in the hot water supply pipe;
Based on the difference between the hot water set temperature preset as the temperature of hot water discharged from the hot water outlet and the temperature detected by the second temperature sensor, the controller is configured to store hot water remaining in the hot water supply pipe. When it is shown that it has cooled, start operation of the reflux pump,
When it is indicated that hot water in the hot water storage tank has been introduced into the hot water supply pipe based on the difference between the hot water set temperature and the temperature detected by the second temperature sensor, the operation of the reflux pump is performed. The hot water supply device according to claim 1, wherein the hot water supply device is stopped. The control unit stops the operation of the recirculation pump when the hot water is supplied from the hot water storage tank to the hot water supply port while the recirculation pump is operated. The hot water supply device according to any one of 4. Along with the supply of hot water from the hot water storage tank to the hot water outlet, a water supply pipe for replenishing the hot water storage tank with water, and a flow rate sensor for detecting the flow rate of water in the water supply path,
The hot water supply device according to claim 5, wherein the control unit detects supply of hot water from the hot water storage tank to the hot water supply port based on a detection result of the flow rate sensor. A heat pump unit having a compressor, a refrigerant-to-water heat exchanger, an expansion valve, a refrigerant-to-air heat exchanger, and a refrigerant pipe that sequentially connects these devices;
A hot water storage unit having a hot water storage tank for storing hot water heated by the refrigerant-to-water heat exchanger, and a hot water supply pipe for supplying hot water stored in the hot water storage tank to a hot water outlet,
A reflux pipe connected between the hot water supply pipe and the hot water storage tank, a reflux pump interposed in the reflux pipe, and a control unit for controlling the operation of the reflux pump;
The control unit operates the reflux pump, returns the hot water cooled in the hot water supply pipe to the hot water storage tank through the reflux pipe, and introduces the hot water in the hot water storage tank into the hot water supply pipe. Heat pump water heater.

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