US-12624862-B2 - Hot water supply apparatus

US12624862B2US 12624862 B2US12624862 B2US 12624862B2US-12624862-B2

Abstract

A hot water supply apparatus includes: a first channel configured to send water in a medium-temperature layer (M) to a heating section; and a second channel configured to return water heated by the heating section to a tank. The second channel has an outflow port at a lower position than an inflow port of the first channel.

Inventors

Yasuhiro Kouno
Hideho SAKAGUCHI

Assignees

DAIKIN INDUSTRIES, LTD.

Dates

Publication Date: 20260512
Application Date: 20230310
Priority Date: 20200930

Claims (8)

1 . A hot water supply apparatus including: a heating section configured to heat water; and a tank configured to store the water heated by the heating section, the hot water supply apparatus being configured to form a low-temperature layer (L), a medium-temperature layer (M), and a high-temperature layer (H) from a lower end to an upper end of the tank, the hot water supply apparatus comprising: a first channel configured to send water in the medium-temperature layer (M) to the heating section; and a second channel configured to return the water heated by the heating section to the medium-temperature layer (M) of the tank, the second channel having an outflow port at a lower position than an inflow port of the first channel, the hot water supply apparatus further comprising a control unit configured to execute: a preparation operation of controlling the hot water supply apparatus so as to create a first hot water storage state in which the low-temperature layer (L), the medium-temperature layer (M), and the high-temperature layer (H) are formed in the tank; and a first operation of causing the water in the medium-temperature layer (M) in the tank in the first hot water storage state to flow through the first channel and causing all the water having flowed from the medium-temperature layer (M) into the first channel to flow through the heating section and the second channel sequentially, after the preparation operation, wherein, in the first operation, the heating section heats water flowing through the first channel, the hot water supply apparatus further comprises: a third channel configured to return the water heated by the heating section to the high-temperature layer (H) of the tank; a fourth channel configured to send water in the low-temperature layer (L) or water from a water source to the heating section; and a plurality of sensors configured to sense the temperatures of the low-temperature layer (L), the medium-temperature layer (M), and the high-temperature layer (H) and the temperature of water exiting from the heating section, and the preparation operation includes: a first preparation step, in response to a sensed temperature of water at the medium-temperature layer (M) being below a first set temperature, the controller is configured to cause water from the low-temperature layer (L) of the tank to flow to the heating section via the fourth channel and return via the third channel until the sensed temperature of water at the medium-temperature layer (M) is the first set temperature; and a second preparation step where, in response to a sensed temperature of water at the high-temperature layer (H) being below a second set temperature and a temperature of the water at the medium-temperature layer being at or above the first set temperature, the controller is configured to cause water from the medium-temperature layer (M) of the tank to flow to the heating section via the first channel and return via the third channel until the sensed temperature of the water at the high-temperature layer (H) is the second set temperature, the heating section heating the water from the medium-temperature layer (M) to a second temperature in the second preparation step, the second temperature being higher than the first temperature.
2 . The hot water supply apparatus of claim 1 , wherein the control unit is further configured to execute a second operation of causing the water in the medium-temperature layer (M) to flow through the first channel, the heating section, and the third channel sequentially.
3 . The hot water supply apparatus of claim 1 wherein the control unit is further configured to execute a third operation of causing the water in the low-temperature layer (L) or the water from the water source to flow through the fourth channel, the heating section, and the second channel sequentially.
4 . The hot water supply apparatus of claim 1 , wherein the control unit is further configured to execute a second operation of causing the water in the medium-temperature layer (M) to flow through the first channel, the heating section, and the third channel sequentially, and a third operation of causing the water in the low-temperature layer (L) or the water from the water source to flow through the fourth channel, the heating section, and the second channel sequentially.
5 . The hot water supply apparatus of claim 4 , wherein the control unit executes a fourth operation of causing the water in the low-temperature layer (L) or the water from the water source to flow through the fourth channel, the heating section, and the third channel sequentially.
6 . The hot water supply apparatus of claim 1 , further comprising: a sensor configured to sense a temperature of the water heated by the heating section before the water heated by the heating section is returned to the tank; a compressor configured to pump water through the heating section; and a valve configured to switch flow of the water from the heating section to one of the second channel or the third channel, wherein the control unit configured to control the valve and the compressor such that compressor operates at a first rate such that water returning to the tank via the second channel has a first temperature and the compressor operates at a second rate such that water returned through the third channel has a second temperature different from the first temperature.
7 . The hot water supply apparatus of claim 1 , wherein the preparation operation of controlling the hot water supply apparatus includes creating the first hot water storage state in which a temperature of the low-temperature layer (L) is below the temperature of the medium-temperature layer (M), the temperature of the medium-temperature layer (M) corresponds to the first set temperature, and a temperature of the high-temperature layer (H) is higher than the first set temperature.
8 . The hot water supply apparatus of claim 7 , wherein the preparation operation of controlling the hot water supply apparatus includes creating the first hot water storage state in which the temperature of the high-temperature layer (H) corresponds to the second set temperature higher than the first set temperature.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a Continuation of PCT International Application No. PCT/JP2021/035326, filed on Sep. 27, 2021, which claims priority under 35 U.S.C. 119 (a) to Patent Application No. 2020-165038, filed in Japan on Sep. 30, 2020, all of which are hereby expressly incorporated by reference into the present application. TECHNICAL FIELD The present disclosure relates to a hot water supply apparatus. BACKGROUND ART A hot water supply apparatus that generates hot water using a heating section and supplies the generated hot water from a tank to a target has been known. Patent Document 1 discloses a hot water supply apparatus configured to form a low-temperature layer, a medium-temperature layer, and a high-temperature layer in a tank. The hot water supply apparatus executes an operation of heating the water in the low-temperature layer, using the heating section, and then returning the water to the medium-temperature layer, and an operation of heating the water in the medium-temperature layer, using the heating section, and then returning the water to the high-temperature layer. As a result of these operations, the low-temperature layer, the medium-temperature layer, and the high-temperature layer are formed in the tank from a lower end portion to an upper end portion of the tank (see FIG. 7 of the document). Accordingly, this tank has less heat dissipation loss than a tank forming only a high-temperature layer. CITATION LIST Patent Document Patent Document 1: WO 2016/001980 SUMMARY A hot water supply apparatus according to a first aspect includes: a heating section (13) configured to heat water; and a tank (30) configured to store the water heated by the heating section (13), the hot water supply apparatus being configured to form a low-temperature layer (L), a medium-temperature layer (M), and a high-temperature layer (H) from a lower end to an upper end of the tank (30), the hot water supply apparatus including: a first channel (41) configured to send water in the medium-temperature layer (M) to the heating section (13); and a second channel (42) configured to return the water heated by the heating section (13) to the tank (30), the second channel (42) having an outflow port (42a) at a lower position than an inflow port (41a) of the first channel (41). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a piping system diagram illustrating a general configuration of a hot water supply unit according to an embodiment. FIG. 2 is a block diagram illustrating a controller and devices connected to the controller. FIG. 3 is a schematic piping system diagram of the hot water supply apparatus and illustrates a first preparation operation. FIG. 4 is a schematic piping system diagram of the hot water supply apparatus and illustrates a second preparation operation. FIG. 5 is a schematic piping system diagram of the hot water supply apparatus and illustrates a first operation. FIG. 6 is a schematic piping system diagram of the hot water supply apparatus and illustrates a second operation. FIG. 7 is a schematic piping system diagram of the hot water supply apparatus and illustrates a third operation. FIG. 8 is a schematic piping system diagram of the hot water supply apparatus and illustrates a fourth operation. FIG. 9 is a schematic piping system diagram of a hot water supply apparatus according to a first variation. FIG. 10 is a schematic piping system diagram of a hot water supply apparatus according to a second variation. FIG. 11 is a schematic piping system diagram of a hot water supply apparatus according to a third variation. FIG. 12 is a schematic piping system diagram of a hot water supply apparatus according to a fourth variation. DESCRIPTION OF EMBODIMENT An embodiment of the present disclosure will be described below with reference to the drawings. The embodiment described below is merely an exemplary one in nature, and is not intended to limit the scope, applications, or use of the invention. Embodiment A hot water supply apparatus (20) according to the present disclosure will be described. <General Configuration> The hot water supply apparatus (20) of the present disclosure is applied to a hot water supply unit (1). The hot water supply unit (1) heats water supplied from a water source, and stores the heated water (hot water) in a tank (30). The water source is a channel through which water is supplied, and includes a water supply system. The hot water in the tank (30) is supplied to a predetermined target. The target includes a shower, a faucet, and a bathtub. As illustrated in FIG. 1, the hot water supply unit (1) includes a heat source apparatus (10), the hot water supply apparatus (20), and a controller (100). <Heat Source Apparatus> The heat source apparatus (10) is a heat source for producing hot water. The heat source apparatus (10) is a heat pump heat source unit. The heat source apparatus (10) includes a refrigerant circuit (11). The refrigerant circuit (11) of the