JP4485406B2 - Hot water storage water heater - Google Patents

Description

  The present invention relates to a hot water storage tank comprising a hot water storage tank for storing the heat storage fluid heated by the heating means, and a hot water supply heat exchanger for exchanging heat between the heat storage fluid stored in the hot water storage tank and the hot water supply water. In particular, the present invention relates to the flow rate control of the primary side circulation circuit of the heat storage fluid to be circulated through the first circulation part of the heat exchanger for hot water supply.

  Conventionally, as this type of hot water storage type hot water supply device, a hot water storage tank for storing a heat storage fluid therein, a heating means comprising a supercritical heat pump cycle for heating the heat storage fluid in the hot water storage tank, and a stored heat storage fluid The first circulation part through which the water flows and the second circulation part through which the hot water supply water circulates are provided adjacent to each other, and the heat storage fluid and the hot water supply water are opposed to each other, and heat exchange is performed between them. There is known a hot water supply apparatus comprising a heat exchanger for hot water supply to be performed and a primary side circulation passage for circulating the heat storage fluid in the hot water storage tank to the first circulation part by the pump means and returning it to the lower part in the hot water storage tank. It has been.

  Furthermore, the apparatus includes first temperature detection means for detecting the temperature of hot water for water flowing into the second circulation part, and flow rate detection means for detecting the flow rate of hot water for water passing through the second circulation part to heat the hot water for hot water. The flow rate of the heat storage fluid flowing through the first circulation portion is determined based on the target temperature when the hot water is detected, the temperature of the hot water supply water detected by the first temperature detection means, and the flow rate of the hot water supply water detected by the flow rate detection means. It is adjusting.

And it is necessary to heat the hot water supply water to the target temperature by adjusting the flow rate of the heat storage fluid flowing through the first flow unit according to the temperature and flow rate of the hot water flow through the second flow unit. A heat storage fluid having a sufficient flow rate can be circulated through the first circulation part. That is, when the heat storage fluid flows out from the first circulation part, the temperature of the heat storage fluid can be lowered to the vicinity of the temperature of the hot water supply water before heating (see, for example, Patent Document 1).
JP 2001-153458 A

  However, in the above-mentioned Patent Document 1, when hot water supply or hot water filling is performed at a high flow rate higher than a predetermined value, the flow rate of hot water circulating in the second circulation section is for storing heat at a high temperature stored above the hot water storage tank. The heat exchange efficiency between the fluid and the hot water supply water is good, and the outlet temperature of the heat storage fluid flowing out from the first circulation part can be reduced.

  However, when hot water supply or hot water filling is performed at a low flow rate that is less than or equal to a predetermined value when the flow rate of hot water flowing through the second flow unit is high, the amount of heat stored in the heat storage fluid flowing through the first flow unit is large. The outlet temperature rises without being sufficiently lowered. As a result, a medium temperature heat storage fluid in a temperature range higher than the water supply temperature is stored in the hot water storage tank.

  Thereby, as a heating means, if the heating means which consists of a supercritical heat pump cycle heated to the high-temperature heat storage fluid like the said patent document 1, for example, the hot water temperature of the heat storage fluid before a heating will become high. When it comes, there is a problem that the operating efficiency (COP = heating capacity / power consumption) decreases due to an increase in the high pressure.

  In view of the above, an object of the present invention is to provide a hot water storage type hot water supply apparatus that is excellent in heat exchange capability between the heat storage fluid and the hot water supply water and that can improve the operating efficiency of the heating means. is there.

In order to achieve the above object, the technical means described in claims 1 to 7 are employed. That is, in the invention described in claim 1, the hot water storage tank (10) for storing the heat storage fluid therein, the heating means (20) for heating the heat storage fluid in the hot water storage tank (10), and the hot water storage tank (10 The first circulation part (30a) through which the heat storage fluid stored in) circulates and the second circulation part (30b) through which the hot water supply circulates are provided adjacent to each other, and the heat storage fluid and the hot water supply water are provided. A hot water supply heat exchanger (30) configured to be opposed to each other and exchanging heat between them, and a heat storage fluid in the hot water storage tank (10) are circulated to the first circulation part (30a), In a hot water storage type hot water supply apparatus comprising a primary side circulation passage (11) for returning to the lower part in the hot water storage tank (10),
Primary circulation passage (11), of the heat storage fluid stored in the hot water storage tank (10), both the heat storage stream of hot heat storage fluid and the medium temperature first flow portion (30a) And when the hot water is circulated and heated in the second flow part (30b), at least the temperature and flow rate of the hot water heated by the hot water heat exchanger (30) The hot water supply control means (40) for adjusting the temperature and the flow rate of the heat storage fluid flowing into the first circulation part (30a) is provided.

  According to this invention, the heat energy of the heat storage fluid according to the hot water supply output of hot water supplied to the second circulation part (30b) side can flow into the first circulation part (30a). The temperature of the heat storage fluid that has flowed out of the one circulation section (30a) can be brought close to the temperature of the hot water supply water before heating.

  Thereby, the heat storage fluid having a low temperature is returned into the hot water storage tank (10), so that the operation efficiency can be improved when the heating means (20) is boiled. Furthermore, it is possible to minimize the heat exchange loss during heat exchange between the heat storage fluid and the hot water supply water, thereby realizing a hot water supply system with excellent heat exchange efficiency.

In the invention according to claim 2, the hot water supply control means (40) includes a primary side inlet temperature detection means (54) for detecting the inlet temperature of the heat storage fluid flowing into the first circulation part (30a), Water supply temperature detecting means (51) for detecting the temperature of the hot water supply water flowing into the second circulation part (30b), and secondary flow rate detection for detecting the flow rate of the hot water supply water passing through the second circulation part (30b) Means (35a, 35b) and secondary outlet temperature detecting means (52) for detecting the outlet temperature of the hot water supply water flowing out from the second circulation part (30b),
Desired hot water supply temperature, target temperature when hot water is heated by the hot water supply heat exchanger (30), inlet temperature of the heat storage fluid detected by the primary side inlet temperature detection means (54), supply water temperature detection means ( 51) The feed water temperature detected by hot water, the flow rate of hot water detected by the secondary flow rate detecting means (35a, 35b), or the hot water detected by the secondary outlet temperature detecting means (52) Based on one of the outlet temperatures, the temperature and the flow rate of the heat storage fluid flowing into the first circulation part (30a) are adjusted.

  According to the present invention, in addition to the temperature and flow rate of hot water heated by the hot water supply heat exchanger (30), specifically, the inlet of the heat storage fluid flowing into the first circulation part (30a). The temperature of the heat storage fluid flowing into the first circulation part (30a) using any of the temperature, the desired hot water supply temperature, the target temperature, or the feed water temperature of the hot water supply water flowing into the second circulation part (30b); The flow rate can be easily controlled. Therefore, even if there is a change on the second circulation part (30b) side, it is possible to exhibit an accurate heat exchange capability according to the change.

  In the invention described in claim 3, the primary side circulation passage (11) is provided with a pump means (17) for circulating the heat storage fluid, and the hot water supply control means (40) rotates the pump means (17). It is characterized by adjusting the flow rate of the heat storage fluid flowing into the first circulation part (30a) by controlling the number. According to the present invention, the flow rate of the heat storage fluid can be easily and quickly adjusted by the pump means (17).

  In the invention according to claim 4, the primary circulation passage (11) is provided with pump means (17) for circulating the heat storage fluid and a flow rate adjusting valve (19) capable of adjusting the flow rate of the heat storage fluid. The hot water supply control means (40) controls the rotational speed of the pump means (17) to a constant level and controls the flow rate control valve (19) to flow the heat storage fluid flowing into the first circulation part (30a). It is characterized by adjusting.

  According to this invention, in the fluctuation range of the flow rate of hot water supplied to the second circulation part (30b) side, when the flow rate is extremely low, it may not be possible to control with the rotational speed of the pump means (17). A flow rate adjusting valve (19) may be used in addition to the pump means (17).

  In the invention according to claim 5, the primary side circulation passage (11) has a medium temperature heat storage fluid taken out from the hot water storage tank (10) and a medium temperature heat storage fluid taken out from the hot water storage tank (10). Is provided with primary side inlet temperature adjusting means (16) for adjusting the temperature of the heat storage fluid flowing into the first circulation part (30a), and the hot water supply control means (40) is provided in the first circulation part. The primary side inlet temperature adjusting means (16) is controlled so that the outlet temperature flowing out of (30a) approaches the vicinity of the feed water temperature of hot water supplying water flowing into the second circulation part (30b). .

  Specifically, according to the present invention, the thermal energy of the heat storage fluid flowing into the first circulation part (30a) is transferred to the second circulation part (30b) by using the primary side inlet temperature adjusting means (16). It can be easily adjusted according to the side.

  In the invention according to claim 6, on the downstream side of the second circulation part (30b), heat exchange is performed by the hot water supply heat exchanger (30) to the hot water supplied by the hot water supply heat exchanger (30). The hot water supply temperature adjusting means (34a, 34b) for adjusting the temperature of the hot water supply water by mixing with the hot water supply water before being heated is provided, and the target temperature is set to a temperature higher by a predetermined temperature than the desired hot water supply temperature. The temperature adjusting means (34a, 34b) mixes the hot water supplied to the target temperature with the hot water supply heat exchanger (30) and the hot water before the heat exchange with the hot water heat exchanger (30). It is characterized by adjusting to a desired hot water supply temperature.

  According to the present invention, the outlet temperature of the hot water supply water on the second circulation part (30b) side is changed to the second circulation part (30b) side by the temperature or flow rate of the heat storage fluid flowing into the first circulation part (30a). When the outlet temperature of the hot water supply water is adjusted, the responsiveness of the temperature change is slow, so the accuracy of temperature control may be reduced. Therefore, in the present invention, when the hot water supply temperature adjusting means (34a, 34b) is used, the temperature of the hot water supply water can be accurately adjusted to the desired hot water supply temperature.

  The invention according to claim 7 is characterized in that the heating means (20) is a supercritical heat pump cycle in which the pressure of the refrigerant becomes equal to or higher than the critical pressure, and heats the heat storage fluid with the refrigerant whose pressure is increased to the critical pressure or higher. It is said.

  According to the present invention, in the supercritical heat pump cycle, when the heat storage fluid is heated to a target temperature (for example, 65 to 90 degrees), the lower the temperature of the heat storage fluid before heating, the lower the high-pressure pressure. Cycle efficiency (COP = heating capacity / power consumption) is improved. Therefore, by heating the heat storage fluid reduced to near the temperature of the hot water supply water before heating in the supercritical heat pump cycle, the operation efficiency can be improved and power saving operation can be performed.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment mentioned later.

(First embodiment)
Hereinafter, a hot water storage type hot water supply apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a schematic diagram showing an overall configuration of a hot water storage type hot water supply apparatus to which the present invention is applied, and FIG. 2 is a flowchart showing a control process of a hot water supply control unit 40 as hot water supply control means.

  The hot water storage type hot water supply apparatus of the present embodiment is used for hot water supply for general household use, such as hot water supply and hot water filling to a bathtub, and as shown in FIG. 1, a hot water storage tank 10 for storing heat storage fluid therein, A heat pump unit 20 that is a heating means for heating the heat storage fluid, a first flow part 30a through which the heat storage fluid flows and a second flow part 30b through which the hot water supply water flows are provided adjacent to each other, and the heat storage fluid The hot water supply heat exchanger 30 is configured to be opposed to the hot water supply water, and exchanges heat between the two. The heat storage fluid is circulated to the first circulation part 30a and returned to the lower part in the hot water storage tank 10. Primary side circulation passage 11 for controlling the operation of this hot water supply system (hot water supply control unit 40, heat source control unit 43) and the like.

  The hot water storage tank 10 of the present embodiment is opened to the atmosphere through the air hole 10a, and the interior of the hot water storage tank 10 is maintained at atmospheric pressure. The hot water storage tank 10 is formed of, for example, a resin material and has a rectangular parallelepiped shape. Further, in order to reduce heat stored in the heat storage fluid in the hot water storage tank 10 from the wall surface of the hot water storage tank 10 to the atmosphere, the outer periphery of the hot water storage tank 10 is covered with a heat insulating material such as glass wool or urethane. May be.

  Further, the heat storage fluid used is mainly water, and preservatives, antifreeze agents, LLC, and the like are added as necessary. In addition to these, a heat storage material having a high specific heat may be encapsulated by a technique such as a microcapsule and dispersed in water, or may be made into a thriller and flowable.

  Further, on the outer wall surface of the hot water storage tank 10, a plurality of (seven in this example) hot water storage thermistors 55, which are water temperature sensors for detecting the amount of hot water stored in the heat storage fluid or the hot water storage temperature, are provided in the vertical direction (of the hot water storage tank 10. The temperature information at each water level of the heat storage fluid filled in the hot water storage tank 10 is output to the hot water supply control unit 40 which is a hot water supply control means described later. Yes.

  Therefore, based on the temperature information from the plurality of hot water storage thermistors 55, the hot water supply control unit 40 has the hot water heated in the upper part of the hot water storage tank 10 and the low temperature heat storage fluid before being heated in the lower part of the hot water storage tank 10. Can be detected, and the hot water temperature of the heat storage fluid at each water level can be detected. Of the plurality of hot water storage thermistors 55, the hot water storage thermistor 55 provided at the uppermost part has a function of detecting the temperature of hot water discharged from the hot storage fluid.

  The heat pump unit 20 that heats the heat storage fluid uses a supercritical heat pump cycle in which, for example, carbon dioxide gas is used as a refrigerant so that the refrigerant pressure on the high-pressure side becomes equal to or higher than the critical pressure of the refrigerant. As is well known, this heat pump cycle includes refrigeration cycle functional parts such as a compressor, a heat exchanger for heating, an expansion valve, an evaporator, and an accumulator (not shown).

  Incidentally, the compressor (not shown) is driven by a built-in electric motor (not shown), compresses the gaseous refrigerant sucked from the accumulator to a critical pressure or more, and discharges it.

  A heating heat exchanger (not shown) exchanges heat between a refrigerant and a heat storage fluid. For example, a refrigerant passage (not shown) through which the refrigerant flows and a heating fluid passage (not shown) through which the heat storage fluid flows are provided. Is a counterflow heating heat exchanger (not shown) that is provided in a double-pipe structure and is configured such that the flow direction of the refrigerant and the flow direction of the heat storage fluid are opposed to each other.

  The expansion valve (not shown) depressurizes the refrigerant flowing out from the heating heat exchanger and supplies it to the evaporator (not shown). An evaporator (not shown) evaporates the refrigerant decompressed by an expansion valve (not shown) by heat exchange with the atmosphere. An accumulator (not shown) gas-liquid separates the refrigerant flowing out of the evaporator, sucks only the gas-phase refrigerant into the compressor, and stores excess refrigerant in the cycle.

  Further, a heating fluid passage (not shown) of the heating heat exchanger is connected to the hot water storage tank 10 via the fluid heating passage 21, and an electric pump (not shown) is operated to store heat in the hot water storage tank 10. The fluid circulates.

  Here, the fluid heating passage 21 is a circulation passage for sending the lowest heat storage fluid in the hot water storage tank 10 to the uppermost portion in the hot water storage tank 10, specifically, the upstream end of the fluid heating passage 21. Is connected to the bottom 10 b of the hot water storage tank 10, and the downstream end of the fluid heating passage 21 is connected to the upper part 10 c of the hot water storage tank 10.

  As a result, the heat storage fluid heated by heat exchange with the refrigerant in the heating heat exchanger (not shown) is sent to the upper part 10c of the hot water storage tank 10, so that the upper part of the hot water storage tank 10 moves from the upper side to the lower side. The heat is then stored in the heat storage fluid. The heat pump unit 20 is operated by a control signal from a heat source control unit 43 described later, and the operation state is output to the hot water supply control unit 40.

  In addition, the actuators in the heat pump unit 20 use AC power as a power source, and mainly heat up the heat storage fluid in the hot water storage tank 10 using midnight power in the midnight time zone where the charge setting is the cheapest. It is carried out.

  Note that, even in the daytime period, when the hot water storage temperature of the heat storage fluid decreases, the boiling operation is controlled. Incidentally, according to the supercritical heat pump cycle, a heat storage fluid having a temperature higher than that of a general heat pump cycle (for example, 85 to 90 ° C.) can be stored therein.

  Next, the primary-side circulation passage 11 causes the heat storage fluid in the hot water storage tank 10 to flow to the first flow section 30a side of the hot water supply heat exchanger 30 described later, and heat is exchanged by the hot water supply heat exchanger 30. Is a circulation passage for returning the stored heat storage fluid to the lower portion 10e in the hot water storage tank 10, and is a high-temperature medium that is a high-temperature take-out pipe 12, a medium-temperature take-out pipe 13, a forward pipe 14, a return pipe 15 It comprises a warm mixing valve 16 and a circulation pump 17 which is a pump means.

  The high-temperature take-out pipe 12 is a pipe for taking out a high-temperature heat storage fluid among the heat storage fluid stored in the hot water storage tank 10, and an upstream end is connected to an upper portion 10 d in the hot water storage tank 10. The medium temperature take-out pipe 13 is a pipe for taking out the medium temperature heat storage fluid having a lower temperature than the high temperature heat storage fluid among the heat storage fluid stored in the hot water storage tank 10. The upstream end is connected to an intermediate portion 10f between 10d and the lower portion 10e.

  The upstream pipe 14 has an upstream end connected to an outlet side of a high / medium temperature mixing valve 16 described later, and a downstream end connected to an upstream end of the first flow section 30a. The upstream end of the return pipe 15 is connected to the downstream end of the first circulation part 30 a, and the downstream end of the return pipe 15 is connected to the lower part 10 e in the hot water storage tank 10.

  The forward pipe 14 is provided with a thermistor 54 before heat exchange which is a primary side inlet temperature detection means for detecting the inlet temperature of the heat storage fluid flowing into the first circulation part 30a. Information is output to a hot water supply control unit 40 described later.

  The high / medium temperature mixing valve 16 is a temperature control valve that is provided at a downstream side junction of the high temperature extraction pipe 12 and the intermediate temperature extraction pipe 13 and adjusts the inlet temperature of the heat storage fluid flowing into the first circulation part 30a. By adjusting the respective opening area ratios, the mixing ratio of the high-temperature heat storage fluid taken out from the high-temperature take-out pipe 12 and the medium-temperature heat storage fluid taken out from the medium-temperature take-out pipe 13 is adjusted.

  The high / medium temperature mixing valve 16 is electrically connected to a hot water supply control unit 40 to be described later. The temperature information of the heat storage fluid detected by the hot water storage thermistor 55 and the pre-heat exchange thermistor 54 and the hot water supply control unit. Control is performed based on the primary target temperature obtained at 40.

  Here, the hot water storage thermistor 55 provided at the uppermost part of the hot water storage tank 10 detects the temperature of hot water discharged from the hot storage fluid, and the hot water storage thermistor 55 provided in the vicinity of the intermediate portion 10f of the intermediate temperature extraction pipe 13 has an intermediate temperature. The temperature of the hot water used to discharge the heat storage fluid is detected.

  And the temperature control is carried out by the high / medium temperature mixing valve 16 so that the inlet temperature of the heat storage fluid detected by the thermistor 54 before heat exchange becomes the primary target temperature. Here, the primary side target temperature is obtained on the basis of the secondary side target temperature of hot water for water exchanged by the hot water supply heat exchanger 30, and is higher than the secondary side target temperature. The target temperature is set.

  Specifically, if the secondary target temperature is, for example, about the set temperature + 5 ° C., the primary target temperature is determined to be about the set temperature + 5 ° C. to 10 ° C. or less. When the hot water storage thermistor 55 provided in the vicinity of the intermediate portion 10f is higher than the primary target temperature, the high / medium temperature mixing valve 16 actively mixes more medium temperature heat storage fluid than high temperature heat storage fluid. The temperature is adjusted.

  In addition, when the hot water storage thermistor 55 provided in the vicinity of the intermediate portion 10f is lower than the primary target temperature, the high and intermediate temperature mixing valve 16 actively mixes more heat storage fluid having a higher temperature than the medium temperature storage fluid. The temperature is adjusted.

  In other words, based on the secondary target temperature of the hot water to be exchanged by the hot water heat exchanger 30, the high / middle temperature mixing valve 16 causes the primary target temperature to be higher than the secondary target temperature. The temperature is adjusted, and the medium temperature heat storage fluid is discharged based on the primary target temperature and the hot water storage thermistor 55 in the vicinity of the intermediate portion 10f. Here, the secondary target temperature is a target temperature referred to in the claims.

  And the circulation pump 17 is arrange | positioned in the middle of the return pipe 15, and is a pump which distribute | circulates the thermal storage fluid in the hot water storage tank 10 to the 1st distribution part 30a. Then, the rotational speed is controlled to be controlled based on the outlet temperature of the hot water supplied by the hot water supply heat exchanger 30 detected by the post-heat exchange thermistor 52 which is a secondary outlet temperature detecting means described later. It is electrically connected to the hot water supply control unit 40.

  In other words, the flow rate of the heat storage fluid flowing into the first circulation part 30a is determined by the rotation of the circulation pump 17 based on the outlet temperature, which is the temperature after the heat exchange of the hot water supplied by the hot water supply heat exchanger 30. It is adjusted by the number.

  In the present embodiment, the flow rate of the heat storage fluid flowing into the first circulation part 30a is adjusted by the number of rotations of the circulation pump 17, but not limited thereto, the return pipe 15 is heated by the hot water supply heat exchanger 30. A primary side post-heat exchange thermistor (not shown) for detecting the outlet temperature of the heat storage fluid after the exchanged heat exchange is provided, and the primary side circulation passage is based on the outlet temperature of the heat storage fluid after the heat exchange. The flow rate circulating through 11 may be controlled by the circulation pump 17.

  According to this, it is possible to provide a regulation value for the rotational speed of the circulation pump 17 so that the outlet temperature of the heat storage fluid returned to the lower portion 10e in the hot water storage tank 10 does not become a predetermined temperature or higher. Therefore, the heat storage fluid having a predetermined temperature or less can be returned to the lower portion 10e in the hot water storage tank 10.

  In addition, drain plugs 18 are respectively provided below the primary side circulation passage 11 and the fluid heating passage 21, and the heat storage fluid in the hot water storage tank 10 and the primary side circulation passage 11 as necessary. Can be drained manually.

  Next, the hot water supply heat exchanger 30 is connected to the first circulation part 30a connected to the primary side circulation passage 11 and through which the heat storage fluid in the hot water storage tank 10 flows, and to the water supply pipe 31 and the hot water supply pipe 32. The second circulation part 30b is arranged and arranged in the vertical direction outside the hot water storage tank 10. The downstream end of the first circulation part 30 a is connected to the return pipe 15 so as to communicate with the lower part 10 e of the hot water storage tank 10, and the upstream end of the first circulation part 30 a is connected to the forward pipe 14.

  On the other hand, as for the 2nd circulation part 30b, the upstream end is connected to the piping 31 for water supply, and the downstream end is connected to the piping 32 for hot water supply. Therefore, the hot water supply heat exchanger 30 has a flow direction of the heat storage fluid flowing from the top to the bottom in the first circulation part 30a and a flow of hot water to flow in the second circulation part 30b from the bottom to the top. It is a counterflow type heat exchanger which is opposite to the direction.

  Further, upstream of the water supply pipe 31, it is connected to a water pipe so that the tap water is led to the second circulation part 30b. The water supply pipe 31 is provided with a water supply thermistor 51 which is a water supply temperature detecting means, and outputs temperature information of tap water flowing through the water supply pipe 31 to the hot water supply control unit 40 which will be described later.

  Further, the hot water supply pipe 32 is provided with a thermistor 52 after heat exchange which is a secondary side outlet temperature detection means for detecting the outlet temperature of the hot water for water exchanged in the second circulation part 30b. The temperature information in 32 is output to a hot water supply control unit 40 described later. The downstream side of the hot water supply pipe 32 is branched into a hot water supply pipe 33a leading to the kitchen and a hot water supply pipe 33b leading to the bathroom.

  The ends of the hot water supply pipes 33a and 33b are connected to hot water faucets (not shown). By opening the hot water faucets, hot water supply to the kitchen, hot water filling to the bathtub, etc. can be performed. Further, in the middle of each of the hot water supply pipes 33a and 33b, hot water supply mixing valves 34a and 34b as hot water supply temperature adjusting means, hot water supply thermistors 53a and 53b, and flow rate counters 35a and 35b as secondary flow rate detection means are provided. It has been.

  The hot water supply mixing valves 34a and 34b are temperature control valves for adjusting the hot water supply temperature of hot water to be discharged to the hot water supply pipes 33a and 33b. By adjusting the ratio of the opening areas of the hot water supply pipes 33a and 33b, The exchanged hot water supply water and the tap water from the water supply pipe 31 are adjusted to adjust the mixing ratio so that the set temperature is a desired hot water supply temperature.

  Incidentally, in this embodiment, the outlet temperature of the hot water for which heat is exchanged in the second circulation part 30b is the secondary target temperature, for example, hot water for about a set temperature of + 5 ° C. is introduced. The hot water mixing valves 34 a and 34 b are electrically connected to a hot water supply control unit 40 to be described later, and hot water supply water detected by the set temperature, the water supply thermistor 51, the heat exchange thermistor 52, and the hot water supply thermistor 53. It is controlled based on the temperature information.

  The hot water supply thermistors 53a and 53b output temperature information in the hot water supply pipes 33a and 33b, and the flow rate counters 35a and 35b output flow rate information in the hot water supply pipes 33a and 33b to the hot water supply control unit 40 described later. The hot-water supply mixing valves 34a and 34b perform feedback control based on the hot-water supply temperature detected by the hot-water supply thermistors 53a and 53b.

  Next, the hot water supply control unit 40 is mainly composed of a microcomputer, and a built-in ROM (not shown) is provided with a preset control program, and temperature information from the thermistors 51 to 55, Based on the flow rate information from the flow rate counters 35a and 35b and the operation signal from the operation switch, the set temperature switch, etc. provided in the kitchen remote control 41 and the bath remote control 42 which are operation panels, the circulation pump 17 and the high / medium temperature mixing valve 16, actuators in the primary circulation passage 11 such as the hot water mixing valves 34a and 34b and the hot water supply pipes 33a and 33b are controlled.

  The heat pump unit 20 is provided with a heat source control unit 43 and is electrically connected to the hot water supply control unit 40. Similarly to the hot water supply control unit 40, the heat source control unit 43 is configured mainly with a microcomputer, and a built-in ROM (not shown) is provided with a preset control program, and various thermistors The actuators in the heat pump unit 20 are controlled on the basis of temperature information and the like.

  Further, in the heat source control unit 43, the hot water storage temperature detected from the hot water storage thermistor 55 provided at the uppermost part in order to keep the hot water temperature of the heat storage fluid heated by the heat exchanger for heating (not shown) at a constant temperature. Based on the above, the rotational speed of the electric pump (not shown) is controlled.

  In the present embodiment, one intermediate temperature extraction pipe 13 is provided in the intermediate part 10f between the upper part 10d and the lower part 10e in the hot water storage tank 10 in the primary-side circulation passage 11, but this is not limiting. An intermediate temperature take-out pipe 13 may be provided, and a switching valve (not shown) for selecting any one of them may be provided.

  According to this, among the heat storage fluid stored in the hot water storage tank 10, the medium temperature heat storage fluid can be taken out more positively than the high temperature heat storage fluid. Thereby, the temperature of the heat storage fluid returned to the lower part 10e in the hot water storage tank 10 can be lowered.

  Next, the operation of the hot water storage type hot water supply apparatus having the above configuration will be described. First, when a power switch (not shown) is turned on, a heat source control unit 43 causes an actuator such as a heat pump cycle part (not shown) and an electric pump (not shown) in the heat pump unit 20 to reach a midnight time zone where the charge setting is cheap. The heat storage fluid in the hot water storage tank 10 is heated by controlling the temperature and the high temperature (for example, 85 ° C.) heat storage fluid is stored in the hot water storage tank 10.

  Then, using the stored high-temperature heat storage fluid as a heat source, the hot water supplied by the hot water supply heat exchanger 30 and the tap water are mixed to supply hot water to a hot water supply target location such as a kitchen, washroom, and bathtub. It is.

  Hereinafter, description will be made based on the flowchart shown in FIG. As shown in FIG. 2, when the user opens a hot water tap (not shown) at the end of the hot water supply pipes 33a and 33b, flow rate information is output to the hot water supply control unit 40 by the flow rate counters 35a and 35b. The Thus, in step 410, it is determined whether or not a hot water supply command has been detected. If a flow rate equal to or greater than a predetermined value is in circulation, the hot water control control process is started by detecting the hot water supply command.

  In step 420, the set temperature input to the hot water supply control unit 40, temperature information from various thermistors, and flow rate information from the flow rate counters 35a and 35b are read and stored. In step 430, it is determined whether or not the input set temperature and flow rate information are changed compared to the stored temperature and flow rate information.

  Here, since it is the first data immediately after the start, it is determined that the set temperature and flow rate information have changed, and the process proceeds to step 440. In step 440, the command rotational speed of the circulation pump 17 is calculated. Specifically, the secondary target temperature is obtained from the stored set temperature. Then, the required hot water supply capacity is obtained based on the secondary target temperature and the flow rate information from the flow rate counters 35a and 35b. Then, the primary target temperature is obtained based on the set temperature or the secondary target temperature.

  And the instruction | indication rotation speed of the circulation pump 17 is calculated from the characteristic of the relationship between the primary side supply capability and instruction | indication rotation speed which were preset based on required hot water supply capacity | capacitance and primary side target temperature. In step 450, the circulation pump 17 is operated at the indicated rotational speed.

  By the operation of the circulation pump 17, the heat storage fluid in the hot water storage tank 10 flows into the first circulation part 30a. In step 460, the heat storage fluid flowing into the first circulation part 30a is changed to the primary side. The temperature is adjusted by the high / medium temperature mixing valve 16 so as to reach the target temperature.

  Thereby, the hot water supply water which distribute | circulates to the 2nd distribution part 30b receives the thermal energy of the fluid for thermal storage, and is heated. In step 470, the rotational speed of the circulation pump 17 is feedback controlled so that the outlet temperature of the hot water supply water detected by the thermistor 52 after heat exchange becomes the secondary target temperature (for example, about the set temperature + 5 ° C.). To do.

  That is, when the outlet temperature detected by the thermistor 52 after heat exchange is lower than the secondary target temperature, the number of revolutions of the circulation pump 17 is increased to increase the flow rate circulating through the primary circulation path 11. As a result, the amount of heat exchange between the heat storage fluid flowing through the first circulation section 30a and the hot water supply water flowing through the second circulation section 30b increases, so that the outlet temperature of the hot water supply water rises.

  Conversely, when the outlet temperature detected by the thermistor 52 after heat exchange is higher than the secondary target temperature, the number of revolutions of the circulation pump 17 is reduced to decrease the flow rate circulating through the primary circulation passage 11. . As a result, the amount of heat exchange between the heat storage fluid flowing through the first circulation section 30a and the hot water supply water flowing through the second circulation section 30b decreases, and the outlet temperature of the hot water supply water decreases.

  If the flow rate or set temperature is changed while the hot water tap is open, whether or not the input set temperature and flow rate information are changed compared to the stored temperature and flow rate information in step 430 described above. If there is a change, the instruction rotational speed of the circulation pump 17 is calculated in step 440. Thereby, the response | compatibility according to a change can be reflected in real time.

  On the other hand, in the high / medium temperature mixing valve 16, feedback control is performed so that the inlet temperature of the heat storage fluid detected by the thermistor 54 before heat exchange becomes the primary target temperature (for example, set temperature + 5 ° C. to 10 ° C. or less). ing. That is, when the inlet temperature of the heat storage fluid detected by the thermistor 54 before heat exchange is lower than the primary target temperature, control is performed such that the high temperature heat storage fluid is increased and mixed with the medium temperature heat storage fluid. .

  In contrast, when the inlet temperature of the heat storage fluid is higher than the primary target temperature, the medium temperature heat storage fluid is increased and mixed with the high temperature heat storage fluid. As a result, the heat storage fluid at a low temperature (for example, about the water supply temperature + 5 ° C.) is returned to the lower portion 10 e in the hot water storage tank 10.

  For example, when the heat storage fluid in the hot water storage tank 10 is heated by the heat pump unit 20 and there are many high temperature heat storage fluids in the hot water storage tank 10 and few medium temperature heat storage fluids, the low temperature heat storage fluid is used. However, the temperature of the heat storage fluid returned to the hot water storage tank 10 is increased upward due to the difference in specific gravity of the heat storage fluid over time. The intermediate layer (medium temperature) is formed between the lower temperature and the upper and lower temperatures.

  On the other hand, in the hot water supply mixing valves 34a and 34ba, hot water supply water having a secondary target temperature (set temperature + about 5 ° C.) exchanged by the second circulation part 30b and tap water supplied from the water supply pipe 31 Are mixed and the temperature is adjusted to the set temperature. Thereby, hot water at a desired hot water supply temperature is supplied from the hot water tap.

  By the way, in the control method of this embodiment, since the circulation flow rate of the primary side circulation passage 11 is adjusted from the beginning based on the amount of hot water supply on the secondary side, the water supply faucet is slightly opened. Rising characteristics are degraded. In order to solve this problem, there is a method of adjusting the flow rate circulating through the primary-side circulation passage 11 as described above after setting the initial rotational speed of the circulation pump 17 high.

  However, in this method, when the flow rate of hot water supplied from the hot water supply pipes 33a and 33b is high, there is little heat exchange loss and the hot water is returned to the lower part 10e in the hot water storage tank 10 at a low temperature. However, in the case of hot water supply with a low flow rate or short-time hot water supply, the amount of heat supplied on the primary side is excessive, and the return temperature to the hot water storage tank 10 is increased.

  Hereinafter, since the return temperature was compared between this method and the present invention, description will be made based on FIG. FIG. 3A shows the rotational speed of the circulating pump 17 when the circulating pump 17 is operated at a rotational speed higher by about 5 seconds after the hot water tap is opened and then the rotational speed of step 470 is feedback controlled. It is a characteristic view which shows the relationship between the primary side exit temperature of a fluid for thermal storage.

  FIG. 3B is a characteristic diagram showing the relationship between the rotational speed of the circulation pump 17 and the primary outlet temperature of the heat storage fluid in accordance with the flowchart shown in FIG. According to this, in FIG. 3A, the heat exchange loss on the primary side of the hot water supply heat exchanger 30 is larger, and the return temperature to the hot water storage tank 10 is higher. Therefore, the low-temperature heat storage fluid can be returned to the lower portion 10e in the hot water storage tank 10 by adjusting the flow rate on the primary side with the number of revolutions based on the amount of hot water supply on the secondary side from the beginning as in the present invention. it can.

  According to the hot water storage type hot water supply apparatus according to the first embodiment described above, the primary side circulation passage 11 mixes both the high temperature and medium temperature heat storage fluids among the heat storage fluid stored in the hot water storage tank 10. Are configured to flow into the first circulation part 30a.

  Thereby, the medium temperature heat storage fluid is used, and the low temperature heat storage fluid can be returned to the lower part 10e in the hot water storage tank 10. Therefore, the operation efficiency can be improved when the heat pump unit 20 is heated.

  In addition, when hot water is circulated and heated in the second circulation part 30b, the first circulation part 30a is supplied to the first circulation part 30a based on at least the temperature and flow rate of the hot water heated by the hot water heat exchanger 30. A hot water supply control unit 40 that adjusts the temperature and flow rate of the inflowing heat storage fluid is provided.

  According to this, the thermal energy of the heat storage fluid according to the hot water supply output of the hot water for water circulated to the 2nd circulation part 30b side can be flowed into the 1st circulation part 30a, and the 1st circulation part 30a. It is possible to make the temperature of the heat storage fluid flowing out from the vicinity of the temperature of the hot water supply water before heating.

  Therefore, the heat storage fluid having a low temperature is returned to the hot water storage tank 10, so that the operation efficiency can be improved when the heat pump unit 20 is heated. In addition, the heat exchange loss on the primary side during heat exchange between the heat storage fluid and the hot water supply water can be minimized, and a hot water supply system with excellent heat exchange efficiency can be realized.

  Specifically, the set temperature, the secondary target temperature that is the target temperature when heating hot water using the hot water supply heat exchanger 30, the inlet temperature of the heat storage fluid detected by the thermistor 54 before heat exchange, the feed water thermistor 51 Flow into the first circulation part 30a based on either the temperature of the feed water detected at the flow rate, the flow rate on the secondary side detected by the flow counters 35a, 35b, or the outlet temperature of the hot water supply water detected by the thermistor 52 before heat exchange. The temperature and the flow rate of the heat storage fluid to be adjusted are adjusted.

  According to this, in addition to the temperature and flow rate of hot water supplied by the hot water supply heat exchanger 30, the inlet temperature of the heat storage fluid flowing into the first circulation part 30a, the desired hot water temperature, the target temperature, Alternatively, it is possible to easily control the temperature and flow rate of the heat storage fluid flowing into the first circulation part 30a by using any one of the feed water temperatures of the hot water flowing into the second circulation part 30b. Therefore, even if there is a change on the second circulation part 30b side, it is possible to exhibit an accurate heat exchange capability corresponding to the change.

  Further, by controlling the number of rotations of the circulation pump 17 and adjusting the flow rate of the heat storage fluid flowing into the first circulation part 30a, the flow rate of the heat storage fluid can be easily and quickly adjusted by the circulation pump 17. .

  Further, a high / medium temperature mixing valve 16 for adjusting the inlet temperature of the heat storage fluid flowing into the first circulation part 30a is provided, and the outlet temperature flowing out of the first circulation part 30a is supplied to the second circulation part 30b. By controlling the high / intermediate temperature mixing valve 16 by the hot water supply control unit 40 so as to approach the vicinity of the supply temperature of the hot water supply water that flows in, the thermal energy of the heat storage fluid flowing into the first flow unit 30a is transferred to the second flow. It is possible to adjust easily according to the part 30b side.

  Also, hot water mixing valves 34a and 34b are provided on the downstream side of the second circulation section 30b, and the hot water mixing valves 34a and 34b are used as hot water water heated to the secondary target temperature by the hot water heat exchanger 30. The tap water from the water supply pipe 31 is mixed and adjusted to a desired hot water supply temperature.

  According to this, the outlet temperature of the hot water supply water on the second circulation part 30b side is set to the outlet temperature of the hot water supply water on the second circulation part 30b side by the temperature or flow rate of the heat storage fluid flowing into the first circulation part 30a. If adjusted, the responsiveness of the temperature change is slow, so the accuracy of temperature control may be reduced. Therefore, in the present invention, if the hot water supply mixing valves 34a and 34b are used, the temperature of the hot water supply water can be accurately adjusted to a desired hot water supply temperature.

  Further, the heat pump unit 20 is a supercritical heat pump cycle in which the pressure of the refrigerant becomes equal to or higher than the critical pressure, and the heat storage fluid is heated by the refrigerant whose pressure is increased to be higher than the critical pressure. When the fluid is heated to a target temperature (for example, 65 to 90 degrees), the lower the temperature of the heat storage fluid before heating, the lower the high-pressure pressure, thereby improving cycle efficiency (COP = heating capacity / power consumption).

  Therefore, by heating the heat storage fluid reduced to near the temperature of the hot water supply water before heating in the supercritical heat pump cycle, the operation efficiency can be improved and power saving operation can be performed.

(Second Embodiment)
In the first embodiment described above, the flow rate of the heat storage fluid flowing into the first circulation part 30a is adjusted by the circulation pump 17, but this is not limiting, and as shown in FIG. The flow rate adjusting valve 19 may be provided to the hot water supply control unit 40 to control the opening degree of the flow rate adjusting valve 19 to adjust the flow rate of the heat storage fluid.

  According to this, in the fluctuation range of the flow rate of the hot water supplied to the second circulation part 30b side, when the flow rate is extremely low, the rotation speed of the circulation pump 17 may not be controlled. Alternatively, the flow control valve 19 may be used.

(Third embodiment)
In the above embodiment, the hot water supply heat exchanger 30 is arranged outside the hot water storage tank 10 to configure the primary-side circulation passage 11, but not limited thereto, specifically, as shown in FIG. The hot water supply heat exchanger 30 may be housed in the hot water storage tank 10. However, at this time, the return pipe 15 of the primary-side circulation passage 11 is disposed in a lower portion in the hot water storage tank 10. The circulation pump 17 is provided in the forward pipe 14.

(Other embodiments)
In the above embodiment, the heat pump unit 20 using carbon dioxide as a refrigerant has been described as a heating unit. However, the present invention is not limited to this, and a general heat pump cycle using a refrigerant such as chlorofluorocarbon or alternative chlorofluorocarbon may be used.

  Moreover, in the above embodiment, the hot water storage tank 10 does not necessarily need to use a resin material, and may be shape | molded with a metal material. Moreover, the shape of the hot water storage tank 10 may not be a rectangular parallelepiped shape but may be a cylindrical shape, for example. In addition, although the hot water storage tank 10 is formed in an open air type, a hot water storage tank having a sealed type structure may be used. In this case, however, parts for protecting the tank such as a pressure reducing valve and a pressure relief valve are required.

It is a schematic diagram which shows the whole structure of the hot water storage type hot water supply apparatus in 1st Embodiment of this invention. It is a flowchart which shows the control processing by the hot water supply control part 40 in 1st Embodiment of this invention. (A) is the characteristic figure which shows the relationship between the rotation speed of the circulation pump 17 when the initial rotation speed is set high, and the primary side exit temperature of the heat storage fluid, (b) is based on the control system in 1st Embodiment. It is a characteristic view which shows the relationship between the rotation speed of the circulation pump 17, and the primary side exit temperature of the heat storage fluid. It is a schematic diagram which shows the whole structure of the hot water storage type hot water supply apparatus in 2nd Embodiment of this invention. It is a schematic diagram which shows the whole structure of the hot water storage type hot water supply apparatus in 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Hot water storage tank 11 ... Primary side circulation passage 16 ... High / medium temperature mixing valve (primary side inlet temperature control means)
17 ... Circulation pump (pump means)
19 ... Flow control valve 20 ... Heat pump unit (heating means)
DESCRIPTION OF SYMBOLS 30 ... Heat exchanger for hot water supply 30a ... 1st distribution | circulation part 30b ... 2nd distribution | circulation part 34a, 34b ... Mixing valve for hot water supply (hot-water supply temperature adjustment means)
35a, 35b ... flow rate counter (secondary flow rate detection means)
40 ... Hot water supply control unit (hot water supply control means)
51 ... Water supply thermistor (water supply temperature detection means)
52 ... Thermistor after heat exchange (secondary outlet temperature detection means)
54 ... Thermistor before heat exchange (primary inlet temperature detection means)

Claims (7)

A hot water storage tank (10) for storing heat storage fluid therein;
Heating means (20) for heating the heat storage fluid in the hot water storage tank (10);
A first circulation part (30a) through which the heat storage fluid stored in the hot water storage tank (10) circulates and a second circulation part (30b) through which the hot water supply water circulates are provided adjacent to each other, and the heat storage fluid And the hot water supply water are configured to face each other, and a hot water supply heat exchanger (30) for exchanging heat between the two,
A primary-side circulation passage (11) for circulating the heat storage fluid in the hot water storage tank (10) to the first circulation part (30a) and returning it to the lower part in the hot water storage tank (10). In the hot water storage hot water supply equipment provided,
The primary side circulation path (11), the hot water storage tank (10) of the heat storage fluid which is stored in said both first flow part and the heat storage flow of hot heat storage fluid and medium temperature Configured to flow into (30a),
And when hot water is circulated through the second circulation part (30b) and heated, the temperature of the hot water heated by the hot water heat exchanger (30) and its flow rate are at least determined. A hot water storage type hot water supply apparatus comprising hot water supply control means (40) for adjusting a temperature and a flow rate of a heat storage fluid flowing into one circulation part (30a). The hot water supply control means (40)
Primary side inlet temperature detection means (54) for detecting the inlet temperature of the heat storage fluid flowing into the first flow part (30a);
A feed water temperature detection means (51) for detecting a feed water temperature of the hot water supply water flowing into the second circulation part (30b);
Secondary flow rate detection means (35a, 35b) for detecting the flow rate of hot water for water passing through the second circulation part (30b);
A secondary-side outlet temperature detecting means (52) for detecting the outlet temperature of the hot-water supply water flowing out from the second circulation part (30b),
Desired hot water supply temperature, target temperature when heating hot water using the hot water supply heat exchanger (30), inlet temperature of the heat storage fluid detected by the primary side inlet temperature detection means (54), the supply water temperature Detected by the hot water supply water temperature detected by the detection means (51), the hot water flow rate detected by the secondary flow rate detection means (35a, 35b), or the secondary outlet temperature detection means (52) 2. The hot water storage device according to claim 1, wherein the temperature and the flow rate of the heat storage fluid flowing into the first circulation part (30 a) are adjusted based on any one of the outlet temperatures of the hot water supply water. Water heater. The primary side circulation passage (11) is provided with pump means (17) for circulating the heat storage fluid,
The hot water supply control means (40) controls the number of rotations of the pump means (17) to adjust the flow rate of the heat storage fluid flowing into the first circulation part (30a). Or the hot water storage type hot-water supply apparatus of Claim 2. The primary side circulation passage (11) is provided with a pump means (17) for circulating the heat storage fluid and a flow rate adjusting valve (19) capable of adjusting the flow rate of the heat storage fluid,
The hot water supply control means (40) controls the rotation speed of the pump means (17) to be constant and controls the flow rate control valve (19) to flow into the first circulation part (30a). The hot water storage type hot water supply apparatus according to claim 1 or 2, wherein the flow rate of the fluid is adjusted. In the primary side circulation passage (11), the high temperature heat storage fluid extracted from the hot water storage tank (10) is mixed with the medium temperature heat storage fluid extracted from the hot water storage tank (10). A primary inlet temperature adjusting means (16) for adjusting the temperature of the heat storage fluid flowing into the one circulation section (30a) is provided;
The hot water supply control means (40) is configured so that the outlet temperature flowing out of the first circulation part (30a) approaches the vicinity of the water supply temperature of hot water flowing into the second circulation part (30b). The hot water storage type hot water supply apparatus according to any one of claims 1 to 4, wherein the secondary side inlet temperature adjusting means (16) is controlled. On the downstream side of the second circulation part (30b), the hot water supply water before the hot water supply heat exchanger (30) exchanges heat with the hot water supply water heat exchanged by the hot water supply heat exchanger (30). Is provided with hot water supply temperature adjusting means (34a, 34b) for adjusting the temperature of hot water supply water,
The target temperature is set to a temperature that is higher than a desired hot water supply temperature by a predetermined temperature,
The hot water supply temperature adjusting means (34a, 34b) is a hot water supply water before the hot water supply water heated to the target temperature by the hot water supply heat exchanger (30) is heat-exchanged by the hot water supply heat exchanger (30). The hot water storage type hot water supply apparatus according to claim 2 , wherein the hot water supply temperature is adjusted to a desired hot water supply temperature.   The said heating means (20) is a supercritical heat pump cycle in which the pressure of the refrigerant becomes equal to or higher than the critical pressure, and heats the heat storage fluid with the refrigerant whose pressure is increased to the critical pressure or higher. The hot water storage type hot water supply apparatus according to any one of 6.

Images