JP4155136B2 - Hot water storage type water heater with heating function - Google Patents

Description

  The present invention relates to a hot water storage type hot-water supply apparatus with a heating function that stores high-temperature hot water heated by a heating means such as a heat pump unit and also enables heating using the stored high-temperature hot water.

  As a conventional hot water storage type hot water supply device having a heating function, for example, one disclosed in Patent Document 1 is known. That is, this hot water storage type hot water supply apparatus heats hot water supplied to the lower side of the hot water storage tank by a heat pump cycle as a heating means and stores it as hot hot water from the upper side of the hot water storage tank. The hot water can be used in a bath or the like, and this high temperature hot water is circulated through, for example, a heat exchanger that heats the heat medium of the floor heating unit to perform a heating function. The low temperature hot water after heat exchange with the heat medium of the floor heating unit is returned between the high temperature hot water in the hot water storage tank and the hot water supply water.

  This makes it difficult for the low-temperature hot water after heat exchange to mix with the hot water, and the heat pump unit can preferentially heat the hot water on the lower side of the hot water storage tank, and the temperature with the high-temperature refrigerant in the heat pump unit. The difference is maintained so as to prevent the heat exchange performance of the heat pump unit from deteriorating.

However, with regard to the operation control of the floor heating unit, the hot water and heat medium circulation pumps are operated based on the detected temperature at a predetermined portion so that heat exchange from the hot water to the floor heating unit is performed satisfactorily. It is only a statement to say. In other words, as the floor heating unit is used, the amount of hot water in the hot water storage tank simply decreases as a matter of course, and the energy used in the heat pump cycle increases to newly heat the hot water supply water. However, it has not yet reached a point where it actively suppresses the increase in energy consumption.
Japanese Patent Laid-Open No. 2003-114053

  The present invention has been made in view of the above points, and provides a hot water storage type hot water supply device with a heating function that can reduce the amount of high-temperature hot water used for heating as much as possible and reduce the energy used by the heating means. With the goal.

  In order to achieve the above object, the present invention employs the following technical means.

In the first aspect of the present invention, the hot water storage tank for storing hot water in the upper portion of the hot water by heating the hot water supplied to the lower portion to the hot water by the heating means (120) provided outside. (110),
A first circulation circuit (130) that circulates so that hot water in the hot water storage tank (110) flows out to the outside and returns to the hot water supply side in the hot water storage tank (110);
A heating device (140) having a second circulation circuit (141) in which the heat medium circulates inside, and performing heating using the heat medium as a heating source;
A heat exchanger (150) provided in the first circulation circuit (130) for heating the heat medium with hot water;
The inside of the second circulation circuit (141) is opened and closed according to the temperature of the predetermined part (142) of the heating device (140), and the temperature of the predetermined part (142) is maintained at the target temperature based on the set temperature set by the user. In a hot water storage type hot water supply apparatus having a heating function having a valve mechanism (144),
After the temperature of the predetermined part (142) is saturated to the target temperature,
When the open / close cycle time of the valve mechanism (144) is shorter than a predetermined cycle time,
The circulation flow rate of the first circulation circuit (130) is stepped until the switching cycle time reaches a predetermined cycle time so that the temperature of the heat medium supplied to the heating device (140) side approaches the temperature of the predetermined part (142). The control means (160) which reduces automatically is provided.

After the temperature of the predetermined part (142) of the heating device (140) is saturated to the target temperature, the heat amount of heat radiated from the heating device (140) may be given to the heat medium, so the switching cycle time is a predetermined cycle. The temperature of the heat medium supplied to the heating device (140) side can be lowered so that time is reached. Therefore, on the first circulation circuit (130) side, the temperature of the hot water after the heat exchange may be lowered with respect to the temperature of the hot water in the heat exchanger (150), and for this purpose, the first circulation circuit (130). , The amount of hot water in the hot water storage tank (110) used can be reduced, and the amount of energy used by the heating means (120) can be reduced.

In addition, since the temperature of the heat medium is lowered, the opening / closing cycle time of the valve mechanism (144) can be lengthened, and the temperature hunting in the vicinity of the target temperature of the predetermined portion (142) is smoothed to heat the user. Feeling can be improved. At this time, appropriate control can be performed while feeding back the flow rate of the first circulation circuit (130) and the temperature of the heat medium so that the open / close cycle time becomes a predetermined cycle time.

  In addition, if the temperature of the heat medium is too low, the heating performance is deteriorated. In this case, the temperature of the heat medium may be increased by increasing the flow rate of the first circulation circuit (130).

The temperature of the predetermined portion (142) is the heating temperature of the heating device (140), the heating medium returned from the heating device (140) side to the heat exchanger (150) side, as in the invention of claim 2. And at least one of the room temperature of the room in which the heating device (150) is installed may be selected.

The invention according to claim 3 is characterized in that the heating means (120) is a heat pump unit (120) using a heat radiation action from a refrigerant compressed to a high temperature and a high pressure.

  As described in the first aspect of the present invention, by reducing the flow rate of the first circulation circuit (130), the hot water after passing through the heat exchanger (150) increases the temperature decrease. Since it returns to the hot water storage tank (110), the rise of the hot water supply water of a lower side part can be suppressed. Therefore, when the heating means is the heat pump unit (120), the temperature difference between the refrigerant in the heat pump unit (120) and the hot water supply is increased, and the coefficient of performance (heat radiation energy relative to the refrigerant compression energy) of the heat pump unit (120) is increased. Ratio) can be improved.

The invention according to claim 4 is characterized in that the refrigerant of the heat pump unit (120) is carbon dioxide.

  When carbon dioxide is adopted as the refrigerant of the heat pump unit (120), the temperature of the refrigerant that heats the hot water supply can be increased by using the supercritical region, and hot water can be efficiently boiled. Carbon dioxide is susceptible to the coefficient of performance due to the temperature difference with hot water. However, in the present invention, since the influence of the temperature difference can be suppressed as described above, the original merit of the heat pump unit (120) using carbon dioxide as a refrigerant can be utilized.

  In addition, the code | symbol in the parenthesis attached | subjected to each said means shows the correspondence with the specific means of embodiment description later mentioned.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic diagram showing a schematic configuration of a hot water storage type hot water supply apparatus (hereinafter referred to as a hot water supply apparatus) 100 with a heating function in the first embodiment.

  The hot water supply apparatus 100 includes a hot water storage tank 110 that stores high temperature hot water heated by the heat pump unit 120, and supplies hot water to a faucet, a shower, a bath, and the like, and a heating function using the high temperature hot water in the hot water storage tank 110. It is supposed to have.

  The hot water storage tank 110 is a metal tank (for example, made of stainless steel) having excellent corrosion resistance, and a heat insulating material (not shown) is arranged on the outer periphery so that hot water can be kept warm for a long time. ing. The hot water storage tank 110 has a vertically long shape, and an introduction port 111 is provided on the bottom surface thereof, and an introduction pipe 112 for introducing hot water (tap water) is connected to the lower side of the hot water storage tank 110. ing.

  On the other hand, a lead-out port 113 is provided on the upper surface of the hot water storage tank 110, and a lead-out pipe 114 for connecting the hot water in the hot water storage tank 110 is connected to the lead-out port 113. The outlet side of the outlet pipe 114 is connected to a faucet, a shower, a bath, and the like.

  A pipe 115 branched from the introduction pipe 112 is connected to the outlet pipe 114, and a mixing valve 116 is provided at the junction of the outlet pipe 114 and the pipe 115. The mixing valve 116 can adjust the mixing ratio of hot water from the outlet pipe 114 and tap water from the pipe 115 by adjusting the opening area ratio.

  The mixing valve 116 is an electric valve that adjusts the opening degree of the outlet pipe 114 and the pipe 115 by driving a valve body by a drive source such as a servo motor, and is operated by a control signal from a control device 160 described later. The operating state is output to the control device 160.

  On the bottom surface of the hot water storage tank 110, a discharge port 117 for discharging hot water of the lower side in the hot water storage tank 110 is provided, and on the upper surface of the hot water storage tank 110, on the upper side of the hot water supply water in the hot water storage tank 110. An inlet 118 for sucking (storing) hot water is provided. The discharge port 117 and the suction port 118 are connected by a heat pump circulation circuit 119, and a part of the heat pump circulation circuit 119 is disposed in a heat pump unit (corresponding to the heating means of the present invention) 120.

  The heat pump unit 120 forms a known heat pump cycle. Here, carbon dioxide is used as the refrigerant, and the refrigerant is compressed to a critical pressure or higher. A heat exchanger (not shown) is provided in a portion of the heat pump circulation circuit 119 disposed in the heat pump unit 120, and a hot water supply water in the hot water storage tank 110 discharged from the discharge port 117 is compressed to a high temperature. The hot water in the hot water storage tank 110 can be boiled (high temperature hot water) by heating it through the heat exchange and returning it to the hot water storage tank 110 from the suction port 118.

  As in this embodiment, by using the supercritical region in the heat pump unit 120, the refrigerant discharge temperature from a compressor (not shown) can be increased. Therefore, hot water (eg, 90 ° C.) can be efficiently boiled up more efficiently than when a chlorofluorocarbon refrigerant or the like is employed. The heat pump unit 120 is operated by a control signal from a control device 160 described later, and outputs an operation state to the control device 160.

  The upstream side of the mixing valve 116 in the outlet pipe 114 and the inlet pipe 112 are connected by a circulation circuit (corresponding to the first circulation circuit of the present invention) 130, and a primary pump 131 is provided in the circulation circuit 130. ing. By the operation of the primary pump 131, hot water is led out from the outlet 113 of the hot water storage tank 110 and returned to the inlet 111 (hot water supply side) of the hot water storage tank 110.

  The primary pump 131 is a variable speed pump and operates so that the circulation flow rate in the circulation circuit 130 can be changed by a control signal from the control device 160 described later and outputs the operation state to the control device 160. I am doing so.

  A heat exchanger 150 is disposed in the middle of the circulation circuit 130. The heat exchanger 150 is a counter flow type heat exchanger, and performs heat exchange between high-temperature hot water flowing through the circulation circuit 130 and a heat medium flowing through a heating circulation circuit 141 described later to heat the heat medium. I have to.

  The floor heating unit (corresponding to the heating device in the present invention) 140 is an indoor heating device, and includes a heating circulation circuit 141, a floor panel 142, a floor sensor 143, a thermal valve 144, and the like.

  The heating circulation circuit (corresponding to the second circulation circuit of the present invention) 141 is provided with a secondary pump 147 so that the internal heat medium (water in this embodiment) is circulated by the secondary pump 147. I have to. The floor panel (corresponding to a predetermined portion in the present invention) 142 is heated using a heat medium as a heating source to heat the room. The floor panel 142 is provided with a floor sensor 143 so as to output a temperature signal of the heated floor panel 142 to the control device 160 described later.

  Further, the heating circulation circuit 141 is provided with a thermally operated valve (corresponding to the valve mechanism of the present invention) 144, and the opening and closing of the valve is controlled by the control device 160 described later. By opening and closing the valve, the heat medium in the heating circulation circuit 141 is circulated or stopped, and the temperature of the floor panel 142 is maintained at the target temperature based on the heating set temperature input to the heating remote controller 162 described later. .

  In the heating circulation circuit 141, the heat medium heated by the heat exchanger 150 flows out to the floor panel 142 (hereinafter referred to as a supply unit 141 a), and the heat medium flows from the floor panel 142 to the heat exchanger 150. Sensors 145 and 146 are provided on the side (hereinafter referred to as return part 141b), and the temperature signal of the heat medium at each part (for example, 55 ° C. for supply part 141a and 50 ° C. for return part 141b) will be described later. The data is output to the control device 160.

  A control device (corresponding to the control means of the present invention) 160 includes temperature signals from the sensors 143, 145, and 146, a hot water switch signal input by the user to the hot water remote controller 161, a hot water set temperature signal, and a user input to the heating remote controller 162. The operation of the mixing valve 116, the heat pump unit 120, each pump 131, 147, and the thermal valve 144 is controlled based on the heating switch signal, the heating set temperature signal, and the like.

  The hot water remote controller 161 is installed near a place where hot water is used, such as in a bathroom or kitchen, the heating remote controller 162 is installed in a room where the floor heating unit 140 is provided, and the main body of the controller 160 is installed in the hot water storage tank 110. Has been.

  Next, the operation of hot water supply apparatus 100 based on the above configuration will be described.

  When the hot water supply switch of the hot water remote controller 161 is turned on by the user, the control device 160 mainly uses the heat pump unit 120 in the late-night time zone (for example, from 23:00 on the current day to 7 o'clock on the next day) when the power rate is inexpensive. Is operated to heat the hot water in the hot water storage tank 110 and store it as hot water. When the user uses hot water in a faucet, shower, bath, etc., the valve opening of the mixing valve 116 is adjusted in accordance with the hot water supply set temperature, and the hot water and tap water are mixed to the tip of the outlet pipe 114. Take out the hot water from.

  When the hot water in the hot water storage tank 110 falls below a predetermined amount, the heat pump unit 120 is operated even outside the midnight time zone to increase boiling water.

  And in this invention, the control at the time of operating the floor heating unit 140 is given, and it demonstrates below using the control flowchart shown in FIG.

  First, it is determined in step S100 whether or not the switch of the heating remote controller 162 is ON. If it is ON, the primary pump 131 and the secondary pump 147 are operated in step S110. If it is determined NO in step S100, the switch ON confirmation is continued.

  In step S120, it is determined from the temperature signal of the floor sensor 143 whether or not the temperature of the floor panel 142 is saturated to the target temperature. If it is determined as NO, the saturation check is continued. Here, the target temperature is a temperature calculated according to a heating set temperature (for example, 30 ° C.) set by the user with the heating remote controller 162, but here, the floor panel 142 showing a direct temperature as a heating device. Therefore, the target temperature is assumed to be equal to the heating set temperature.

  If it is determined in step S120 that the temperature of the floor panel 142 (floor sensor 143) is saturated, the temperature of the heat medium in the supply unit 141a obtained from the sensor 145 is decreased by a predetermined amount (here, 2 degrees) in step S130. The rotational speed of the next pump 131 is decreased by a predetermined amount.

  The reason for reducing the rotational speed of the primary pump 131 is based on the following idea. That is, after the temperature of the floor panel 142 saturates to the target temperature, the amount of heat radiated from the floor panel 142 into the room may be given to the heat medium, so that the temperature difference between the sensors 145 and 146 is the same. However, the absolute value of the temperature of the heat medium may be lowered so as to approach the floor panel 142. For this purpose, the temperature of the hot water on the outflow side of the heat exchanger 150 in the circulation circuit 130 may be reduced (for example, the temperature difference between the inflow side and the outflow side of the heat exchanger 150). This increases the circulation flow rate of the circulation circuit 130.

  Then, in step S140, the opening / closing cycle time of the thermal valve 144 is compared with a predetermined cycle time determined in advance (here, 30 minutes to 1 hour). If the opening / closing cycle time is shorter than the predetermined cycle time, the process proceeds to step S130. Then, the rotational speed of the primary pump 131 is further reduced by a predetermined amount.

  If it is determined in step S140 that the open / close cycle time has become equal to the predetermined cycle time, the process proceeds to step 150, and the open / close cycle time is maintained until the heating switch is turned off.

  When it is determined in step S140 that the opening / closing cycle time has become longer than the predetermined cycle time, the temperature of the heat medium obtained from the sensor 145 is increased by a predetermined amount (here, 2 degrees) in step S160. The rotational speed is increased.

  If it is determined in step S150 that the heating switch has been turned off, both the primary pump 131 and the secondary pump 147 are stopped in step S170, and the heating control is terminated.

  From the above configuration explanation and operation explanation, in the present invention, the circulation flow rate of the circulation circuit 130 is lowered so as to lower the temperature of the heat medium of the supply unit 141a after the temperature of the floor panel 142 is saturated to the heating set temperature (target temperature). Since the opening / closing cycle time of the thermal valve 144 is set to a predetermined cycle time, the amount of hot water in the hot water storage tank 110 is reduced and the amount of energy (electric power) used by the heat pump unit 120 is reduced. Can be reduced. That is, it is possible to suppress the boiling of hot water outside the midnight time zone and to cope with the boiling up by cheap electric power in the midnight time zone as much as possible.

  In addition, since the temperature of the heat medium in the supply unit 141a is lowered, the open / close cycle time of the thermal valve 144 can be lengthened, and the temperature hunting in the vicinity of the target temperature of the floor panel 142 can be smoothed to the user. Heating feeling can be improved. At this time, appropriate control can be performed by feeding back the flow rate of the circulation circuit 130 and the temperature of the heat medium so that the open / close cycle time becomes a predetermined cycle time. In addition, if the temperature of the heat medium is too low, the heating performance is deteriorated. At that time, the temperature of the heat medium may be increased by increasing the flow rate of the circulation circuit 130.

  FIG. 3 shows the result of confirming the temperature of the heat medium in the supply unit 141a based on the above control, the floor panel 142 (data at three points in the representative part), and the opening / closing cycle time of the thermal valve 144 for a predetermined time after temperature saturation. Is shown. As the temperature of the heat medium decreases, the open / close cycle time of the thermal valve 144 increases, and the temperature change (temperature hunting) of the floor panel 142 also becomes smooth.

  Further, by reducing the circulation flow rate of the circulation circuit 130, the hot water after passing through the heat exchanger 150 increases the temperature drop and returns to the hot water storage tank 110, so that the hot water supply at the lower side is increased. Can be suppressed. Therefore, when the heating means is the heat pump unit 120, the temperature difference between the refrigerant in the heat pump unit 120 and the hot water supply is increased to improve the coefficient of performance (the ratio of the heat radiation energy to the refrigerant compression energy) of the heat pump unit 120. be able to.

  In the present embodiment, carbon dioxide is adopted as the refrigerant of the heat pump unit 120, but the temperature of the refrigerant that heats the hot water supply can be increased by using the supercritical region, and the hot water is efficiently boiled. However, carbon dioxide is susceptible to the coefficient of performance due to the temperature difference with hot water. However, in the present invention, since the influence of the temperature difference can be suppressed as described above, the original merit of the heat pump unit 120 using carbon dioxide as a refrigerant can be utilized.

(Other embodiments)
In the first embodiment, the temperature of the floor panel 142 is used as a predetermined portion in order to determine whether or not the target temperature with respect to the heating set temperature is saturated. However, the temperature is not limited to this, and the heat medium temperature in the return portion 141b. (Sensor 146), the room temperature of the room in which the floor heating unit 140 is installed, and a combination of the temperature of the floor panel 142 and the room temperature as shown in FIG. Incidentally, FIG. 4 is exhibited by the Research Committee on Amenity Evaluation of Floor Heating, and more comfortable heating is performed by incorporating the temperature range indicated by the hatched portion in FIG. be able to.

  Moreover, although demonstrated as what was applied to the floor heating unit 140 as a heating apparatus, you may apply to a bathroom dryer, a panel heater, a fan convector, an underfloor heat radiator, etc. in addition to this.

  Further, although carbon dioxide is used as the refrigerant of the heat pump unit 120, the invention is not limited to this, and a CFC refrigerant (R410 or the like) may be used.

  Furthermore, the heating means is not limited to the heat pump unit 120 but may be an electric heater or the like.

It is a schematic diagram which shows schematic structure of the hot water storage type hot water supply apparatus with a heating function in 1st Embodiment of this invention. It is a flowchart which shows the control flow at the time of the heating of the hot water storage type hot water supply apparatus with a heating function. It is a time chart which shows the temperature of a heat medium, the temperature of a floor panel, and the open / close state of a thermal valve when the control shown in FIG. 2 is performed. It is a map which shows the comfortable range at the time of heating in floor panel temperature and room temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Hot water storage type hot water supply apparatus with a heating function 110 Hot water storage tank 120 Heat pump unit (heating means)
130 Circulation circuit (first circulation circuit)
140 Floor heating unit (heating device)
141 Circulation circuit for heating (second circulation circuit)
142 Floor panel (predetermined part)
144 Thermally operated valve (valve mechanism)
150 heat exchanger 160 control device (control means)

Claims (4)

A hot water storage tank (110) for storing hot water in the hot water by the heating means (120) provided outside is heated to hot water by replenishing the lower side, and storing the hot water in the upper side of the hot water.
A first circulation circuit (130) that circulates so that hot water in the hot water storage tank (110) flows out to the outside and returns to the hot water supply side in the hot water storage tank (110);
A heating device (140) having a second circulation circuit (141) in which a heat medium circulates inside, and performing heating using the heat medium as a heating source;
A heat exchanger (150) provided in the first circulation circuit (130) for heating the heat medium with the hot water;
The inside of the second circulation circuit (141) is opened / closed according to the temperature of the predetermined part (142) of the heating device (140), and the temperature of the predetermined part (142) is based on the set temperature set by the user. In a hot water storage hot water supply apparatus with a heating function having a valve mechanism (144) for maintaining
After the temperature of the predetermined portion (142) is saturated with the target temperature,
When the opening / closing cycle time of the valve mechanism (144) is shorter than a predetermined cycle time,
The first circulation circuit (130) until the opening / closing cycle time reaches the predetermined cycle time so that the temperature of the heat medium supplied to the heating device (140) side approaches the temperature of the predetermined portion (142). ) Is provided with control means (160) for stepwise reduction of the circulating flow rate . The temperature of the predetermined part (142) includes the heating temperature of the heating device (140), the temperature of the heat medium returned from the heating device (140) side to the heat exchanger (150) side, and the heating device (150). The hot water storage type hot-water supply apparatus with a heating function according to claim 1 , wherein the temperature is set to at least one of the room temperatures of a room in which is installed. The hot water storage type hot water supply with heating function according to claim 1 or 2 , wherein the heating means (120) is a heat pump unit (120) using a heat radiation action from a refrigerant compressed to a high temperature and a high pressure. apparatus. The hot water storage type hot water supply apparatus with a heating function according to claim 3 , wherein the refrigerant is carbon dioxide.

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