JP2005241088A - Hot water storage type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the lowering of COP caused by the generation of the water of intermediate temperature, in a hot water storage type water heater wherein the hot water in a bathtub is reheated by using the hot water stored in the hot water storage tank. <P>SOLUTION: This hot water storage type water heater comprising a hot water storage tank unit, a capacity-variable compressor, a refrigerant-water heat exchanger, an expansion valve, an air heat exchanger and the like, further comprises a heating means for heating the hot water in the hot water storage tank, and a capacity-variable circulation pump forming a circulation circuit by connecting the hot water storage tank and the refrigerant-water heat exchanger by a water inlet pipe and a hot water outlet pipe, and the hot water in the hot water storage tank is circulated to the refrigerant-water heat exchanger of the heating means through the circulation circuit by driving the circulation pump, to be heated, and then returned to the hot water storage tank to heat the hot water in the hot water storage tank. A water temperature sensor is mounted on an inlet of the refrigerant-water heat exchanger or the water inlet pipe, a hot water tapping temperature sensor is mounted on an outlet of the refrigerant-water heat exchanger or the hot water outlet pipe, a flow rate c of the circulation pump is controlled on the basis of temperature difference t between a value b of the water temperature sensor and a value a of a hot water temperature sensor, and the rotational frequency of the compressor and an opening of the expansion valve are controlled on the basis of the flow rate c of the circulation pump. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hot water storage type hot water supply apparatus that uses hot water stored in a hot water storage tank to replenish hot water in a bathtub.

Conventionally, in this type of electric water heater and heat pump hot water storage type hot water supply device, hot water in the bathtub can be reheated using the hot water stored in the hot water tank. If this temperature is equal to or higher than the predetermined temperature, the bath circulation pump is driven to circulate the bath water to the heat exchanger and perform a reheating operation by exchanging heat with the hot water in the hot water storage tank. .
JP 2003-50048 A

  However, in this conventional system, when the hot water storage temperature sensor detects that the necessary amount of heat does not remain in the hot water storage tank the next day in the midnight power time zone, the cooking operation is started and compressed at a constant rotational speed. The machine is operated and the circulation pump is driven at a constant flow rate. For example, as shown in FIG. 4, if the hot water storage tank 2 has a capacity of 450 liters and the remaining hot water is 225 liters and is a medium temperature water of 50 ° C., about 17 ° C. The low temperature water is heated to a high temperature of about 65 ° C. with a refrigerant-water heat exchanger, returned to the hot water storage tank from the hot water pipe connected to the upper part of the hot water storage tank 2, and sequentially stacked from the upper part of the hot water storage tank. We will store hot water. The energy consumption efficiency (hereinafter referred to as COP) at this time is about 3.23. However, if there is medium-temperature water (about 50 ° C.) generated by the hot-pot cooking operation, the rise in the incoming water temperature (about 50 ° C.). C.) has a drawback that COP is significantly reduced (2.22 in this case).

  Accordingly, in order to solve the above problems, the present invention provides a hot water storage tank unit having a hot water storage tank in which hot water is stored by connecting a water supply pipe and a hot water supply pipe, a variable capacity compressor, and refrigerant-water. A heat exchanger, an expansion valve, an air heat exchanger, and the like, and a heating means for heating the hot water in the hot water storage tank, and the hot water storage tank and the refrigerant-water heat exchanger are connected by a water inlet pipe and a hot water outlet pipe for circulation. And a variable capacity circulation pump that circulates hot water in the middle of the circulation circuit, and the hot water in the hot water storage tank is driven by the circulation pump through the circulation circuit to generate refrigerant-water heat of the heating means. In a hot water storage hot water supply apparatus that heats the hot water in the hot water storage tank by circulating and heating to the exchanger and returning it back to the hot water storage tank, an incoming water temperature sensor is provided at the inlet of the refrigerant-water heat exchanger or the inlet pipe, Refrigerant-water heat exchanger outlet or A tapping temperature sensor is provided in a tapping pipe, the flow rate c of the circulation pump is controlled according to the temperature difference t between the value b of the incoming water temperature sensor and the value a of the tapping temperature sensor, and the compression is performed according to the flow rate c of the circulation pump. The rotation speed of the machine and the opening degree of the expansion valve are controlled.

  According to a second aspect of the present invention, there is provided a current sensor for detecting the current value d1 of the heating means, and an inlet temperature sensor is provided at the inlet of the refrigerant-water heat exchanger or the inlet pipe, and the outlet of the refrigerant-water heat exchanger or the hot water. A hot water temperature sensor is provided in the pipe, a temperature difference t between the water temperature sensor value b and the hot water temperature sensor value a is calculated, and COP control means for maintaining t × c / d1 at a predetermined value x is provided. The rotation speed of the compressor and the opening degree of the expansion valve are controlled by the means.

  According to a third aspect of the present invention, there is provided a current sensor for detecting the current value d2 of the heating means and the hot water storage tank unit, and an inlet water temperature sensor is provided at the inlet or inlet pipe of the refrigerant-water heat exchanger, and the refrigerant-water heat exchange. A hot water temperature sensor is provided at the outlet or the hot water pipe, COP control means is provided for calculating a temperature difference t between the water temperature sensor value b and the hot water temperature sensor value a, and maintaining t × c / d2 at a predetermined value y. The COP control means controls the rotation speed of the compressor and the opening degree of the expansion valve.

  As described above, according to the present invention, even when medium-temperature water is generated by the chasing operation, the flow rate of the circulation pump, the rotation speed of the compressor, and the like are automatically adjusted to provide a highly efficient water heater. It is something that can be done.

  In addition, the COP is simply calculated from the temperature difference between the set hot water temperature and the incoming water temperature and the power consumption, and the flow rate of the circulation pump and the rotational speed of the compressor are automatically adjusted to maintain a high COP and are extremely efficient. A hot water heater can be provided.

  Next, an embodiment of the present invention will be described with reference to the drawings.

  In this hot water storage type hot water supply apparatus, hot water is boiled and stored in the midnight hours when the unit price of contracted power by time zone is low, and the hot water stored in the hot water is used for hot water supply. 1 is a hot water storage tank 2 for storing hot water. 3 is a heat pump unit as a heating means for heating hot water in the hot water storage tank, 4 is a hot water tap provided in a kitchen or a washroom, etc. 5 is a remote control for remotely operating the hot water storage type hot water supply device , 6 is a bathtub.

  The hot water storage tank 2 of the hot water storage tank unit 1 has a hot water supply pipe 7 connected to the upper end, a water supply pipe 8 connected to the lower end, a water inlet pipe 9 constituting a heat pump circulation circuit in the lower part, and a heat pump circulation circuit in the upper part. The hot water in the hot water storage tank 2 taken out from the incoming water pipe 9 by the heat pump unit 3 is boiled up and returned to the hot water storage tank 2 from the hot water storage pipe 2 to be stored in the hot water storage tank 8. As a result, hot water in the hot water storage tank 2 is pushed up, and hot water in the upper part of the hot water storage tank 2 is pushed out from the hot water supply pipe 7 to be supplied with hot water.

The heat pump unit 3 includes a compressor 11 having a variable number of revolutions, a refrigerant-water heat exchanger 12 as a condenser, an expansion valve 13, a forced air-cooled evaporator 14, and a hot water storage tank 2. A circulating pump 16 that circulates the hot water to the refrigerant-water heat exchanger 12 through the water inlet pipe 9 and the hot water outlet pipe 10, and a heat pump control unit 17 that controls the driving thereof. Is one in which carbon dioxide is used as a refrigerant to constitute a supercritical heat pump cycle. Since carbon dioxide is used as the refrigerant, it is possible to boil low temperature water to a high temperature of about 90 ° C. without an electric heater.
The power source of the compressor 11 or the heat pump unit 3 is provided with a current sensor 18 that always detects the current value d1 of the compressor 11 or the heat pump unit 3 as a whole.

Reference numeral 19 denotes an incoming water temperature sensor attached to the inlet pipe 9 or the inlet of the refrigerant-water heat exchanger 12, and detects the water temperature before being heated by the refrigerant-water heat exchanger 12 by a thermistor sensor or the like.
A hot water temperature sensor 20 is attached to the outlet pipe 10 or the outlet of the refrigerant-water heat exchanger 12, and detects the hot water temperature heated by the refrigerant-water heat exchanger 12 by a thermistor sensor or the like.

  Here, the refrigerant-water heat exchanger 12 employs a counter flow system in which the refrigerant and hot water in the hot water storage tank 2 that is heated water face each other, and in the supercritical heat pump cycle, the refrigerant is exchanged during heat exchange. The water to be heated can be efficiently heated to a high temperature because it is condensed in the supercritical state, and according to the temperature difference t between the refrigerant-water heat exchanger 12 inlet temperature b and the refrigerant outlet temperature a. In addition to controlling the rotational speed of the expansion valve 12 or the compressor 11, the COP control means 21 for controlling the flow rate c of the circulation pump 16 is provided, so that the water to be heated is heated in a very good COP state. Is possible.

  Next, 22 is a heat exchanger made of a stainless steel snake tube for heating the hot water in the bathtub 6, and is arranged at the upper part in the hot water storage tank 2. A bath circulation circuit 26 comprising a bath return pipe 25 provided with a bath circulation pump 24 is connected so that hot water in the bathtub 6 can be circulated, and the hot water in the bathtub 6 is heated by the high-temperature water in the hot water storage tank 2 to keep warm. Or it is something that is chased.

  27 is a bath return temperature sensor that detects the temperature of the bath water flowing into the heat exchanger 22 through the bath return pipe 25, and 28 is a bath that flows out of the heat exchanger 22 and flows into the bath 6 through the bath forward pipe 23. This is a temperature sensor 28 that detects the temperature of water.

  Next, 29 is a hot water mixing valve composed of an electric mixing valve that mixes hot water from the hot water supply pipe 7 and low temperature water from the water supply bypass pipe 30 branched from the water supply pipe 8. The mixing ratio is controlled so that the hot water temperature detected by the provided hot water temperature sensor 32 becomes the hot water supply set temperature set by the user using the remote controller 5.

  Reference numeral 33 denotes a hot water filling pipe branched from the hot water supply pipe 31 and communicated with the bath return pipe 25. The hot water filling pipe 33 includes a hot water filling valve 34 for starting / stopping hot water filling to the bathtub 6, and a bathtub 6. A bath flow counter 35 that counts the amount of hot water filled in and a check valve 36 that prevents the bath water from flowing back to the hot water supply pipe 31 are provided.

  Next, a plurality of hot water storage temperature sensors 37 are arranged in the vertical direction of the hot water storage tank 2. In this embodiment, five hot water storage temperature sensors are arranged and are referred to as 37a, 37b, 37c, 37d, 37e from the top. The amount of heat remaining in the hot water storage tank 2 is detected based on the temperature information detected by the temperature sensor 37, and the vertical temperature distribution in the hot water storage tank 2 is detected.

  A hot water supply control unit 38 includes a microcomputer that receives the input of each sensor in the hot water storage tank unit 1 and controls driving of each actuator, and constitutes a control unit. The remote controller 5 is connected to the hot water supply control unit 38 by wireless or wired so that the user can set an arbitrary hot water set temperature and bath set temperature.

  The hot water supply control unit 38 receives outputs of the plurality of hot water storage temperature sensors 37a to 37e, and determines whether the remaining heat amount in the hot water storage tank 2 is sufficient based on the detected temperatures. 39 is provided.

  The remote controller 5 is provided with a hot water supply temperature setting switch 40 for setting the hot water supply set temperature and a bath temperature setting switch 41 for setting the bath set temperature, and hot water at the bath set temperature is supplied to the bathtub 6 of the remote control 5. A bath automatic switch 42 that fills the hot water amount set by a hot water amount setting switch (not shown) and keeps it warm for a predetermined time, a reheating switch 43 that retreats the bathtub water, and hot water in the hot water storage tank 2 A reheating switch 44 for increasing a certain amount even during the daytime period is provided. The remote controller 5 is provided with a dot matrix display unit 45, a speaker 46 for outputting a buzzer sound and voice guidance, and a remote control unit 47 for controlling them.

  Further, in a partial area of the display unit 45, a hot water storage amount display unit 48 for visually displaying the remaining hot water amount in the hot water storage tank 2 is provided, which is calculated by the residual heat amount determination unit 39. The number of lighting of the bar display indicating the remaining hot water is changed in the figure simulating the hot water storage tank 2 according to the remaining hot water amount.

  The remote control unit 47 is provided with a character information memory 49 that stores character information to be displayed on the display unit 45 and a voice synthesis IC 50 that stores voice guidance voices notified from the speaker 46.

  Note that 51 is an overpressure relief valve for releasing the overpressure of the hot water storage tank 2, 52 is a pressure reducing valve for reducing the pressure of the water supply, 53 is a hot water supply flow counter for counting the amount of hot water to be supplied, and 54 is for detecting the temperature of the water supply. It is a feed water temperature sensor.

  The COP control means 21 includes a current value d1 of the heat pump unit 3 as a heating means, a temperature difference t between the value a of the hot water temperature sensor 20 and the value b of the incoming water temperature sensor 19, and the flow rate c of the circulation pump 16 to t × The number of revolutions of the compressor 11 and the opening degree of the expansion valve 13 are controlled so as to calculate a rough COP by calculating c / d1 and maintain the predetermined value x.

  Note that the COP of this type of hot water storage type hot water supply device can be obtained by the formula {(hot water temperature a-water temperature b) × circulation flow rate c ÷ power consumption}. Therefore, the calculation formula (t × c / d1) is simply calculated by using the current value d1 instead of the power consumption and determining the predetermined value x.

Next, the operation of the first embodiment will be described.
First, the reheating operation of the bath will be described. When the reheating switch 43 of the remote controller 5 is turned on, a start condition check of the reheating operation is performed, and the remaining heat amount determination unit 39 of the hot water supply control unit 38 enters the hot water storage tank 2. The hot water storage temperature detected by the attached hot water storage temperature sensor 37 is checked. If the hot water storage temperature in the vicinity of the heat exchanger 22 is equal to or higher than a predetermined temperature (here, 50 ° C.), the remaining amount of heat can be replenished. Since the start condition is satisfied and the bath circulation pump 24 is started to drive, the hot water stored in the upper part of the hot water storage tank 2 and the bath water are subjected to heat exchange. When the temperature detected by the bath return temperature sensor 27 reaches the reheating target temperature, the hot water supply control unit 38 stops driving the bath circulation pump 24 and ends the reheating operation.

  Then, after the chasing operation is stopped, the user can recognize that the chasing operation has been stopped by a buzzer sound and voice guidance from the remote controller 5 at a remote location, and the display unit 45 of the remote controller 5. In addition, the fact that the chasing operation has been stopped is displayed by text information, and the hot water storage amount display section 48 blinks, so that it is intuitively understood that the chasing operation has been stopped due to insufficient hot water storage. Can be recognized.

  At this time, the hot water temperature in the hot water storage tank 2 is a high temperature water region of 65 to 90 ° C. above the heat exchanger 22, a medium temperature water region in which heat is taken away by the additional cooking operation of the bath, and the temperature is lowered. If the amount of heat used for the additional cooking operation is large, the temperature of the medium temperature water will eventually reach about 50 ° C., and the uppermost high temperature water will be separated into three layers in the low temperature water region of the feed water temperature (5 to 20 ° C.) It is used for hot water supply in order.

  Next, when the hot water storage temperature sensor 37 detects that the necessary amount of heat does not remain in the hot water storage tank 2 in the midnight power time zone, the hot water supply control unit 38 instructs the heat pump control unit 17 to start boiling. To emit. Upon receiving the command, the heat pump control unit 17 starts driving the compressor 11 and then starts to drive the circulation pump 16, and cool water of about 5 to 20 ° C. taken out from the water inlet pipe 9 connected to the lower part of the hot water storage tank 2. Heated to a high temperature of about 65 to 90 ° C. with the heat exchanger 12, returned to the hot water storage tank 2 from the hot water discharge pipe 10 connected to the upper part of the hot water storage tank 2, and sequentially stacked from the upper part of the hot water storage tank 2 to store the hot water. To go. When the hot water storage temperature sensor 37 and the hot water temperature sensor 20 detect that the necessary amount of heat has been stored, the hot water supply control unit 38 issues a boiling stop command to the heat pump control unit 17, and the heat pump control unit 17 turns on the compressor 11. At the same time, the circulating pump 16 is stopped and the boiling operation is finished.

  The timing chart of FIG. 3 will be described. This shows a case where the remaining hot water of 50 ° C. is present up to an intermediate water level (225 liters) of the 450 liter hot water storage tank 2 by the bathing operation. 2 Low temperature water of about 17 ° C. taken out from the inlet pipe 9 connected to the lower part is heated to a high temperature of about 65 ° C. by the refrigerant-water heat exchanger 12, and hot water is stored from the outlet pipe 10 connected to the upper part of the hot water storage tank 2. The hot water is stored in the tank 2 by laminating the hot water tank 2 in order from the top. If the flow rate c of the circulation pump 16 at this time is 1.1 liters / min and the current value of the compressor 11 is 5.7 A, the COP will be about 3.23, and the operation will be continued until the low-temperature water disappears. If it continues for 4 hours, the medium temperature water of 50 ° C. reaches the inlet pipe 9.

If medium temperature water is detected by the incoming water temperature sensor 19, the COP control means 21 calculates t × c / d1, and the compressor 11 rotates in order to maintain the same level of COP as when low temperature water is heated. The number increases and changes to a current value of 8.4 A, the opening of the expansion valve 13 is automatically adjusted to the optimum opening according to the rotation speed of the compressor 11, and the flow rate of the circulation pump 16 is also 1 .6 liter / min.
Further, since the circulation flow rate increases, the boiling time is about 5.7 hours, which is 1.1 hours shorter than the conventional example.

  Next, the hot water supply operation will be described. When the hot water tap 4 is opened, the water supplied from the water supply pipe 8 flows into the hot water storage tank 2. The hot water stored in the hot water storage tank 2 flows into the hot water supply mixing valve 29 through the hot water supply pipe 7 and is mixed with the low temperature water from the hot water supply bypass pipe 30, and the hot water control section 38 sets the mixing ratio of the hot water supply mixing valve 29. The adjusted hot water at the hot water supply set temperature is supplied from the hot water tap 4. Then, the hot water supply is completed by closing the hot water tap 4.

  Next, the hot water filling operation to the bathtub 6 will be described. When the automatic bath switch 42 of the remote controller 5 is operated, the hot water supply control unit 38 opens the hot water filling valve 34. Then, the hot water adjusted to the set temperature by the hot water supply mixing valve 29 is poured from the hot water filling pipe 33 to the bathtub 6 through the hot water return pipe 25, and a bath flow rate counter 35 provided in the middle of the hot water filling pipe 33 is predetermined. When the amount of hot water filling is counted, the hot water supply control unit 38 closes the hot water filling valve 34 and ends the hot water filling operation.

  In addition, it is not limited to said Example 1 of this invention, The same effect can be acquired even if it changes to the incoming water temperature sensor 18 and applies the detection temperature of the hot water storage temperature sensor 32 to the value b. .

  Further, even if the total operating current value d2 of the heat pump unit 3 and the hot water storage tank unit 1 which are heating means is used instead of the current value d1 of the heating means, the same value can be obtained by setting the predetermined value to y by the COP control means 21. An effect can be obtained.

The schematic block diagram of the hot water storage type hot-water supply apparatus of the Example of this invention. The principal part block diagram of the Example. The timing chart figure explaining the action | operation of the Example. The timing chart explaining the action | operation of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot water storage tank unit 2 Hot water storage tank 3 Heat pump unit 6 Bath 11 Compressor 12 Refrigerant-water heat exchanger 13 Expansion valve 16 Circulation pump 19 Incoming water temperature sensor 20 Hot water temperature sensor 21 COP control means

Claims (3)

  A hot water storage tank unit having a hot water storage tank connected to the hot water supply pipe and a hot water storage tank, and a variable capacity compressor, a refrigerant-water heat exchanger, an expansion valve, an air heat exchanger, etc. A heating means for heating the hot water in the tank, the hot water storage tank and the refrigerant-water heat exchanger are connected by a water inlet pipe and a hot water outlet pipe to form a circulation circuit, and a variable capacity for circulating hot water in the middle of the circulation circuit. A circulating pump, and the hot water in the hot water storage tank is heated by circulating the hot water in the hot water storage tank through the circulation circuit to the refrigerant-water heat exchanger of the heating means and returning it to the hot water storage tank. In the hot water storage type hot water supply apparatus for heating the hot water in the tank, an inlet temperature sensor is provided at the refrigerant-water heat exchanger inlet or inlet pipe, and an outlet temperature sensor is provided at the refrigerant-water heat exchanger outlet or outlet pipe, Value b of the incoming water temperature sensor and The flow rate c of the circulation pump is controlled according to the temperature difference t of the value a of the hot water temperature sensor, and the rotational speed of the compressor and the opening degree of the expansion valve are controlled according to the flow rate c of the circulation pump. Hot water storage type hot water supply device.   A hot water storage tank unit connected with a hot water supply pipe and a hot water supply pipe and having a hot water storage tank for storing hot water therein; a variable capacity compressor; a refrigerant-water heat exchanger; an expansion valve; an air heat exchanger; A heating means for heating the hot water in the tank, the hot water storage tank and the refrigerant-water heat exchanger are connected by a water inlet pipe and a hot water outlet pipe to form a circulation circuit, and a variable capacity for circulating hot water in the middle of the circulation circuit. A circulating pump, and the hot water in the hot water storage tank is heated by circulating the hot water in the hot water storage tank through the circulation circuit to the refrigerant-water heat exchanger of the heating means and returning it to the hot water storage tank. The hot water in the tank is heated and a bath circulation pump is provided in the hot water storage tank to circulate the hot water in the bathtub, and the hot water stored in the hot water storage tank is provided in the bath circulation circuit. In addition In the hot water storage type hot water supply apparatus, wherein the bath circulation pump is driven to circulate the bath water to the bath heat exchanger and re-drive the bath heat exchanger, the current value of the heating means a current sensor for detecting d1, a water temperature sensor at the refrigerant-water heat exchanger inlet or water inlet pipe, a water temperature sensor at the refrigerant-water heat exchanger outlet or water outlet pipe, and a water temperature sensor of the water temperature sensor. A COP control means is provided for calculating a temperature difference t between the value b and the tapping temperature sensor value a, and maintaining t × c / d1 at a predetermined value x. By this COP control means, the rotational speed of the compressor and the opening of the expansion valve are provided. Hot water storage type hot water supply device characterized by controlling the degree.   A hot water storage tank unit having a hot water storage tank connected to the hot water supply pipe and a hot water storage tank, and a variable capacity compressor, a refrigerant-water heat exchanger, an expansion valve, an air heat exchanger, etc. A heating means for heating the hot water in the tank, the hot water storage tank and the refrigerant-water heat exchanger are connected by a water inlet pipe and a hot water outlet pipe to form a circulation circuit, and a variable capacity for circulating hot water in the middle of the circulation circuit. A circulating pump, and the hot water in the hot water storage tank is heated by circulating the hot water in the hot water storage tank through the circulation circuit to the refrigerant-water heat exchanger of the heating means and returning it to the hot water storage tank. The hot water in the tank is heated and a bath circulation pump is provided in the hot water storage tank to circulate the hot water in the bathtub, and the hot water stored in the hot water storage tank is provided in the bath circulation circuit. In addition In the hot water storage type hot water supply apparatus, wherein the bath circulation pump is driven and the bath water is circulated through the bath heat exchanger so as to carry out reheating operation, the heating means and the hot water storage tank A current sensor for detecting the current value d2 of the unit, a water temperature sensor at the refrigerant-water heat exchanger inlet or water inlet pipe, a water temperature sensor at the refrigerant-water heat exchanger outlet or water outlet pipe, A temperature difference t between the value b of the entry water temperature sensor and the value a of the tapping water temperature sensor is calculated, and COP control means for maintaining t × c / d2 at a predetermined value y is provided. By this COP control means, the rotational speed of the compressor A hot water storage type hot water supply device that controls the opening degree of an expansion valve.

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