JP3909310B2 - Heat pump water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat pump water heater, and relates to a heat pump water heater having a bath chasing function.
[0002]
[Prior art]
A conventional heat pump water heater has a large-capacity hot water storage tank, just like an electric water heater, and uses cheap discount electricity at night to boil hot water in the heat pump circuit and store it in the hot water storage tank. A hot water storage system that uses hot water during the day was common.
[0003]
However, in the above hot water storage system, the amount of hot water in the hot water storage tank is constant, the amount of hot water is insufficient on days when the amount of use is large, and the amount of energy lost due to cooling of the remaining hot water on days when the amount of use is small.
[0004]
In addition, in the case of bath use, after hot water is filled in the bathtub, if the hot water cools down, it is necessary to retreat, but the conventional hot water storage system has only one-sided hot water function from the hot water storage tank, so it can respond appropriately. could not.
[0005]
As the above improvement measures, there is one disclosed in Japanese Patent Application Laid-Open No. 2003-56904 (Patent Document 1) as a heat pump water heater to which a chasing function is added.
[0006]
In the heat pump water heater described in Patent Document 1, the refrigerant (carbon dioxide) that has been compressed by the compressor and becomes high temperature and high pressure circulates in the heat pump circuit having the refrigerant-water heat exchanger, whereby the refrigerant in the heat pump circuit is obtained. Heat is transferred from water to water, warming the water. The warmed water circulates through a hot water storage tank or circulates through a water-water heat exchanger through which the water in the bathtub circulates. The heated water circulates in the hot water tank, so that the water in the hot water tank is boiled. In addition, the heated water circulates through the water-water heat exchanger, thereby chasing the cold water in the bathtub.
[0007]
That is, by using carbon dioxide as a refrigerant, water can be heated to about 90 ° C. in a water-refrigerant heat exchanger, so that not only boiling water in hot water storage tanks but also replenishing water in bathtubs is a heat pump. It is disclosed to do with a circuit.
[0008]
[Patent Document 1]
JP 2003-56904 A
[0009]
[Problems to be solved by the invention]
In the heat pump water heater disclosed in Patent Document 1, when the faucet is opened, water is supplied from the water supply to the lower part of the hot water storage tank, and hot water in the upper part of the hot water storage tank is pushed out by this water and mixed with the cold water of the water supply by the mixing valve. The hot water is supplied at an appropriate temperature.
[0010]
That is, the heat pump water heater of Patent Document 1 performs heat pump operation only at night to store hot water in a hot water storage tank, and then does not perform heat pump operation, and bath water with a full hot water storage tank. It covers all water supply for upholstery, toilets, kitchens, etc.
[0011]
Therefore, an actual hot water storage tank having a large capacity of 300 to 450 L is used. If CO2 refrigerant is used, hot water as high as 90 ° C. can be stored, but energy loss due to natural heat dissipation increases as the temperature increases.
[0012]
Such a large-capacity hot water storage tank requires sufficient strength of the installation space and the installation floor. Because, when hot water is stored to the full capacity of the hot water storage tank, the mass reaches 500 kg, so the foundation construction at the installation site must be done to ensure sufficient strength, such as the verandas of apartments and apartments. It becomes difficult to install in a narrow place or a place with insufficient strength. Furthermore, when transporting the heat pump type hot water heater to the installation site of the customer, much cost and labor are required.
[0013]
In addition, the electricity rate is set at night discount and the heat pump is operated at night, and hot water is stored in the hot water storage tank. During the day, the heat pump is not operated in principle, and the hot water stored in the hot water storage tank is used. Use it.
[0014]
For this reason, sometimes the hot water in the hot water storage tank was used up, and it was not possible to boil it up immediately, causing hot water to run out. Also, in order to store a large amount of hot water at a temperature higher than the ambient temperature for a long time, heat is dissipated from the large surface of the hot water storage tank, resulting in energy loss. there were.
[0015]
Therefore, although the heat pump water heater of patent document 1 has the cost merit by night discount charge, the subject remained in the point of energy saving and global warming.
[0016]
Therefore, as one solution to prevent energy saving and global warming in the heat pump water heater, there is an instantaneous hot water supply method in which hot water is not stored as much as possible and a necessary amount of hot water is supplied when necessary. However, in order to realize an instantaneous hot water supply type heat pump device, unheated clean water must be heated in a very short time. For example, the capacity of the compressor is increased and the heat transfer capacity of the water-refrigerant heat exchanger is increased. There are issues such as up. In particular, when trying to discharge hot water at the water pressure of the water supply, if the water heat transfer tube through which water flows is made narrower or longer in order to increase heat transfer capacity, the pressure loss in the water heat transfer tube will increase, and sufficient water pressure will be provided at the time of hot water discharge. I found a problem that I could not obtain.
[0017]
  The object of the present invention is to save energy by solving the above-mentioned problems.NeThe object is to provide an excellent heat pump water heater.
[0018]
[Means for Solving the Problems]
  In order to achieve the above object, the heat pump water heater of the present invention comprises:
  A compressor, a water-refrigerant heat exchanger that exchanges heat between the refrigerant compressed by the compressor and water, a decompression device that decompresses the heat-exchanged refrigerant, and heat exchange between the decompressed refrigerant and air An evaporator for performing a heat pump refrigerant circuit respectively connected by a refrigerant line;
  An instantaneous hot water supply circuit that heats water supplied from a water supply unit by the water-refrigerant heat exchanger and instantaneously supplies the heated hot water to a hot water outlet terminal;
  After the start of operation of the instantaneous hot water supply circuit, an auxiliary tank that transiently assists hot water supply from the instantaneous hot water circuit,
  A water-water heat exchanger for reheating a bath connected to a branch pipe branched from the instantaneous hot water supply circuit;
  A water on-off valve disposed between the instantaneous hot water supply circuit and the water-water heat exchanger on the branch pipe;
  The water on-off valve is closed when instantaneous hot water is supplied to the hot water terminal using the instantaneous hot water supply circuit,
It is a configuration.
[0019]
By adopting such a configuration, the water heated by the water-refrigerant heat exchanger can reduce the heat transfer from the hot water discharged to the unnecessary unit to the minimum on the route to the hot water outlet terminal such as a faucet or bathtub. This enables energy-saving operation.
[0020]
When the hot water heated to a desired temperature by the water-refrigerant heat exchanger is routed outside the hot water terminal, the valve is opened and the circulation pump draws the hot water from the hot water piping to the branch. That is, when reserving water accumulated in the bathtub, the valve is opened to the branch pipe branched from the hot water supply circuit, and hot water heated to the water-water heat exchanger is drawn by the circulation pump, and the water in the auxiliary tank is also drawn. When boiling water, the valve is opened on the branch pipe branched from the hot water supply circuit, and hot water heated by the water-refrigerant heat exchanger is drawn in by the circulation pump, so that heat transfer leakage from the water heated by the heat pump circuit is piped. The road configuration can be made as low as possible and can be operated efficiently.
[0021]
In addition, the water-water heat exchanger, which is a heat exchanger for bath remembrance, can be a compact heat exchanger by adopting a double tube structure in which a heat transfer tube is mounted inside a cylindrical tube. Since the entire outer periphery of the inner tube through which the bath circulating water flows can be heated with the heated circulating water, the heat transfer efficiency can be improved far more than in the conventional method in which separate heat transfer tubes are brought into contact with each other.
[0022]
Further, when hot water is discharged from the hot water supply circuit immediately after the start of the heat pump operation, the hot water stored in the auxiliary tank is supplied together to supply hot water, so that the shortage of water supply heating at the start of operation can be compensated. Insufficient feed water heating at the start of heat pump operation is a short time of about 1 to 2 minutes, and the size of the auxiliary tank is as small as 1/3 to 1/5 that of a conventional hot water storage tank. Therefore, at the time of initial installation of the heat pump water heater of the present invention, the water storage in the tank is completed earlier than before, and the boiling can be done in a short time, so that it can be used earlier than the conventional midnight power utilization type. You can wait in the state.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS. The heat pump water heater shown in FIG. 1 includes a heat pump refrigerant circuit 30, a hot water supply circuit 40, and operation control means 50.
[0024]
The heat pump refrigerant circuit 30 includes two refrigeration cycles. In each cycle, the compressors 1a and 1b, the condensers 2a and 2b, the decompression devices 3a and 3b, and the evaporators 4a and 4b are sequentially connected via refrigerant pipes. Is enclosed.
[0025]
The compressors 1a and 1b capable of capacity control are operated with a large capacity when a large amount of hot water is supplied. The compressors 1a and 1b are controlled in rotational speed from low speed rotation (for example, 2000 rotations / minute) to high speed rotation (for example, 8000 rotations / minute) by PWM control, voltage control (for example, PAM control) and combination control thereof.
[0026]
The water-refrigerant heat exchanger 2 includes refrigerant side heat transfer tubes 2a and 2b and feed water side heat transfer tubes 2e and 2f which are condensers in the refrigeration cycle. For example, heat exchange is performed between the refrigerant side heat transfer tubes 2a and 2b and the water supply side heat transfer tubes 2e and 2f by a configuration described later.
[0027]
The evaporators 4a and 4b are air-refrigerant heat exchangers that perform heat exchange between air and the refrigerant.
[0028]
The defrosting electromagnetic valves 5a and 5b are open / close valves that open while the electromagnetic coil provided is energized. The solenoid valves 5a and 5b bypass the high-temperature and high-pressure refrigerant gas discharged from the compressors 1a and 1b to the inlet side of the evaporators 4a and 4b. When the evaporators 4a and 4b are frosted in winter, the solenoid valves 5a and 5b open the on-off valves so that the high-temperature and high-pressure refrigerant gas discharged from the compressors 1a and 1b is connected to the evaporators 4a and 4b with refrigerant piping. It works by flowing through and melting frost.
[0029]
The hot water supply circuit 40 has a configuration that realizes a water circulation circuit necessary for hot water storage, hot water supply, hot water bathing, bath bathing, and the like by switching pipes.
[0030]
The heat pump hot water supply circuit is a main hot water supply circuit of the heat pump water heater of this embodiment. The water taken in from the water supply fitting 6 which is a connection port with the water supply is depressurized by the pressure reducing valve 7 and sent to the bypass valve 8. The bypass valve 8 is a proportional valve that not only distributes water to the water-refrigerant heat exchanger 2 or the auxiliary tank 9 but also distributes water to the branch pipe 2i for temperature adjustment of hot water to be discharged. The clean water that has passed through the water supply check valve 23 from the bypass valve 8 is warmed by the water supply heat transfer pipes 2e and 2f through the water supply pipe 2c. The warmed water is discharged from the heat pump water heater to the outside of the heat pump water heater 13 through the hot water supply pipe 2d via the heat exchange flow rate adjustment valve 11 and from the hot metal fitting 13 connected to the hot water supply pipe 2d. Each configuration is sequentially connected through a water pipe.
[0031]
The tank hot water supply circuit includes an auxiliary tank 9, and this auxiliary tank 9 is formed of a cylindrical and small-sized tank formed in a vertically long shape, and is 1/3 of the hot water storage tank provided in a conventional hot water storage type hot water supply machine. It is a small hot water storage tank of ~ 1/5. And the auxiliary | assistant tank 9 stores the hot water of a certain high temperature which can be mixed with the warm water from a heat pump hot-water supply circuit, when the temperature of the hot water supplied by a heat pump hot-water supply circuit is low.
[0032]
Specifically, the hot water stored in the auxiliary tank 9 flows out to the hot water discharge pipe 2d through the branch pipe 2h when the tank flow rate adjusting valve 12 is opened. At this time, the warm water is sent out from the auxiliary tank 9 because the clean water supplied through the water supply fitting 6 is injected into the auxiliary tank 9 with the water pressure adjusted through the water pipe through the pressure reducing valve 7 and the bypass valve 8. Because.
[0033]
The hot water storage circuit used when warming the water in the auxiliary tank 9 is configured between the auxiliary tank 9 and the water-refrigerant heat exchanger 2. That is, the tank flow rate adjustment valve 12 connected to the branch pipe 2h branched from the hot water supply pipe 2d is opened, and the tank circulation pump 10 draws water from the lower part of the auxiliary tank 9. The drawn water is subjected to heat exchange through the water supply pipe 2c and the water supply heat transfer pipes 2e and 2f. The hot water that has passed through the hot water supply pipe 2 d passes through the heat exchange flow rate adjustment valve 11 and the tank flow rate adjustment valve 12 and is guided to the auxiliary tank 9. This hot water storage circuit is also used when reheating hot water in the auxiliary tank 9, in other words, pursuing hot water in the auxiliary tank 9.
[0034]
The basic structure of the bath hot water supply circuit for supplying hot water to the bathtub is the same as that of the heat pump hot water supply circuit, and hot water is distributed to the branch pipe 2j branched from the hot water supply pipe 2d instead of hot water from the hot metal fitting 13. By opening the bath pouring valve 14 connected to the branch pipe 2j, hot water is injected into the bathtub 18 passing through the bath sensor fitting 15 and connecting to the bath outlet fitting 16. Of course, when the hot water is filled in the bathtub 18, the hot water supply from the auxiliary tank 9 to the bathtub 18 is not limited to the minimum required amount in addition to the direct hot water supply from the water-refrigerant heat exchanger 2. To do.
[0035]
The bath remedy circuit that reheats the hot water in the bathtub 18 is a water conduit between the bathtub 18 and the water-water heat exchanger 20. After the water drawn from the bathtub 18 by the bath circulation pump 19 through the hot metal fitting 17 is sent to the bath heat transfer pipe 20 b and heated by heat exchange, the temperature of the hot water is measured after passing through the bath sensor fitting 15. The hot water is supplied to the bathtub 18 through the hot metal fitting 16.
[0036]
Next, control of the heat pump water heater in this embodiment will be described. The operation control means 50 of the heat pump water heater performs the operation / stop of the heat pump refrigerant circuit 30 and the rotation speed control of the compressors 1a, 2b according to the operation settings of the kitchen remote controller 51 and the bath remote controller 52, and the tank circulation pump 10, bath By controlling the operation / stop of the circulation pump 19 and the bypass valve 8, the heat exchange flow rate adjustment valve 11, the tank flow rate adjustment valve 12, the hot water solenoid valve 14, and the water on / off valve 21, hot water storage operation, hot water supply operation, Driving and memorial operation.
[0037]
The operation control means 50 is preferably controlled to operate at a high rotational speed faster than the normal hot water supply operation speed in order to shorten the heating start-up time immediately after the heat pump circuit starts operation. In addition, after use of hot water supply at the hot water outlet terminal, the hot water storage operation function is provided every time the operation is stopped after the tank hot water storage operation is performed.
[0038]
Next, other control-related equipment provided in the heat pump water heater in the present embodiment will be described. Similar to the detection of the hot water supply temperature to the bathtub 18 by the bath sensor fitting 15, the temperature of the water heated by the water-refrigerant heat exchanger 2, the water stored in the auxiliary tank 9, the hot water to be discharged, and other A temperature sensor that detects the temperature state of each part, a pressure sensor that detects the discharge pressure of the compressors 1a and 2b, a water level sensor that detects the water level in the bathtub 17, and the like (both not shown) are provided. Input to the operation control means 50. The operation control means 50 controls each device based on these signals.
[0039]
The water on-off valve 21 is connected to the branch pipe 2g branched from the hot water supply circuit, and is provided at a position between the water-refrigerant heat exchanger 2 and the bath heat exchanger 20. The water circuit to the bath heat exchanger 20 is closed except during bathing to prevent heat leakage from the water-refrigerant heat exchanger 2 to the bath heat exchanger 20. For example, if this water on-off valve 21 is not provided and the hot water supply piping 2d of the hot water supply circuit and the bath heat exchanger 20 that is a water-water heat exchanger are continuous through the water in the pipe, Even if water does not flow into the branch pipe 2g, it is thermally continuous, so heat leakage proceeds from the bath heat exchanger 20. Similarly, also in the branch pipes 2h, 2i, and 2j branched from the hot water supply pipe 2d, a pipe configuration in which the tank flow rate control valve 12, the bypass valve 8 and the bath pouring valve 14 connected at the ends of the branch pipes are opened and closed as necessary. As a result, heat leakage during hot water supply is extremely reduced.
[0040]
Moreover, the bath check valve 22 and the water supply check valve 23 flow water only in one direction, respectively, to prevent backflow. The bath pouring valve 14 is also required to have the same function. That is, the water up to the branch pipe 2j is water or warm water, but the water in the bathtub 18 is at the tip of the bath pouring valve 14, and the water in the bathtub 18 is mixed upstream of the branch pipe 2j. For there should not be anything to do.
[0041]
The relief valve 24 operates when the hot water pressure in the auxiliary tank exceeds a predetermined level, and functions to protect the device against pressure.
[0042]
An embodiment of the water-refrigerant heat exchanger 2 will be described with reference to FIG. The water-refrigerant heat exchanger 2 has two refrigerant heat transfer tubes 2a and 2b and two water supply heat transfer tubes 2e and 2f. The refrigerant heat transfer tubes 2a and 2b and the feed water electric heat tubes 2e and 2f are alternately arranged. The structure is rolled up in a cylindrical shape by contact.
[0043]
The feed water heat transfer pipes 2e and 2f are located in the water-refrigerant heat exchanger 2 and heated by the water feed pipe 2c through which water taken in through the water feed fitting 6 or water from the auxiliary tank 9 passes and the water-refrigerant heat exchanger 2 are heated. It is a pipe line divided into two in parallel with the outlet pipe 2d through which the water is passed. Compared to the case of one, the water flow area of the feed water heat transfer tubes 2e, 2f and the contact area with the refrigerant heat transfer tubes 2a, 2b are doubled, so that the individual length can be halved, The internal resistance during water flow can be reduced to ¼. Accordingly, the internal pressure loss of the water-refrigerant heat exchanger 2 during water flow is also reduced to ¼ compared to the case of one, and the overall height can be lowered, making manufacture and storage easy.
[0044]
In particular, when instantaneous hot water supply such as instantaneous hot water supply using gas is performed using a heat pump, water circulation is attempted by the water pressure of the water supply source. However, the internal pressure loss of the water-refrigerant heat exchanger 2 becomes a resistance during direct water flow and becomes negative to the tapping pressure. For example, when the water supply pressure is 200 kPa, if there is a pressure loss of 100 kPa in the conventional water-refrigerant heat exchanger, the hot water pressure becomes 100 kPa, and there is a risk that the water pressure will drop and the amount of hot water will be insufficient. However, in the case of the water-refrigerant heat exchanger 2 in the present embodiment, the pressure loss is ¼ 25 kPa, so that the tapping pressure is 175 kPa, and a sufficient water pressure and tapping amount can be maintained. In the heat pump water heater that heats hot water directly with a heat pump and supplies hot water with the function of chasing the water in the bathtub, the structure of the water-refrigerant heat exchanger 2 in this embodiment performs heat exchange between water and the refrigerant. The heat exchange efficiency of the water-refrigerant heat exchanger is further increased by separating the bath heat exchanger from the water-refrigerant heat exchanger.
[0045]
Next, an example of the heat exchanger 20 for bath remedy will be described with reference to FIG. The bath heat exchanger 20 has a double tube structure, and a space 20c partitioned by a bath water heat transfer tube 20b is provided inside a hot water heat transfer tube 20a using a copper tube. Warm water heated by the water-refrigerant heat exchanger 2 flows through the space 20c through hot water pipes 20d connected to both ends of the hot water heat transfer pipe 20a. The bath water heat transfer tube 20b through which hot water in the bathtub flows is connected to a bath water pipe 20e led out from both end portions 20f of the hot water heat transfer tube 20a. The hot water heat transfer pipe 20a is a copper straight pipe that is generally used, and squeezes both ends 20f of the hot water heat transfer pipe 20a so as to be joined and sealed to the outside of the bath water pipe 2e. The bath water heat transfer tube 20b has a concave / convex shape, a star shape, a multi-leaf tube or the like in order to increase the contact area with the hot water. The hot water pipe 20d opens to both ends of the hot water heat transfer pipe 20a and is electrically connected to the space 20c through which the hot water flows.
[0046]
The bath heat exchanger 20 has a double pipe structure as described above, so that the bath water heat transfer pipe 20b through which water in the bathtub 18 that is a heated body flows is in the circulation space of hot water that is a heated body. Is provided. Therefore, the bath water heat exchanger 20 has a bath water heat transfer tube 20b that transfers heat on the entire outer periphery thereof, and can be a compact water / water heat exchanger with good heat transfer.
[0047]
In the conventional heat exchanger for bath remedy, heat is exchanged between the refrigerant heat transfer tube and the bath water heat transfer tube.If the inner tube is damaged, the high pressure refrigerant enters the water circuit and the There is a risk of affecting the drinking water system that is the drinking water inside, and a double pipe structure in which one pipe penetrates the other inside cannot be adopted. As shown in FIG. It had to be an independent piping structure.
[0048]
In addition, the bath memory heat exchanger 20 considers the following points. That is, the circulating water of bath water may contain impurities. If this bath water flows through the space 20C side, impurities are trapped by irregularities on the tube surface, which may cause clogging. Therefore, in this embodiment, the hot water having passed through the water-refrigerant heat exchanger 2 is allowed to flow through the space 2C.
[0049]
That is, in the embodiment of the present invention, the bath recuperation heat exchanger 20 and the water-refrigerant heat exchanger 2 are separated, and the water-water heat exchange between the heated circulating water and the bath circulating water is performed so as to be duplicated. It can be said that the adoption of a pipe structure has become possible.
[0050]
With the configuration described above, the heat pump water heater in the present embodiment starts the heat pump operation simultaneously with the start of use of the hot water supply, and can directly supply the hot water boiled in the water-refrigerant heat exchanger 2 to the hot water outlet terminal. 18 hot water is chased by a heat exchanger 20 for baths having a double-pipe structure to obtain an energy saving and warming prevention effect.
[0051]
Next, the operation of the heat pump water heater will be described based on the flowcharts of FIGS. 4 to 7 with reference to the heat pump circuit 30 and the hot water circuit 40 of FIG.
[0052]
FIG. 4 is an example of a flowchart showing the operation during installation. The heat pump water heater is transported from the manufacturing site and installed at the installation location desired by the user (step 60), the water supply fitting 6 is connected to a water supply source such as water supply, and the main plug of the water supply source is opened (step 61). Then, water supply is started from the water supply source (step 62), and the water is decompressed and adjusted to a constant pressure by the pressure reducing valve 7, and then flows into the hot water storage tank 9, the water-refrigerant heat exchanger 2 and each water pipe and is full. Water supply is continued until it becomes (step 63).
[0053]
In addition, each apparatus at the time of installation of a heat pump water heater is set to the following initial states. The bypass valve 8 is open on the auxiliary tank 9 side and closed on the branch pipe 2i side, which is the hot metal fitting 13 side. The heat exchange flow rate adjustment valve 11, the tank flow rate adjustment valve 12, and the water on-off valve 21 are all open. 14 is in a closed state.
[0054]
Next, when full water is confirmed in step 63, it is determined that the water supply is completed, and the power switch is turned on (step 64). Then, the operation of the heat pump refrigerant circuit 30 and the hot water supply circuit 40 is started under the control of the operation control means 50, and the tank hot water storage operation is performed (step 65). In this tank hot water storage operation, the operation of the compressors 1a and 1b is started, and the gaseous refrigerant in the compressors 1a and 1b is compressed and heated to be a high-temperature and high-pressure refrigerant and sent to the water-refrigerant heat exchanger 2.
[0055]
As a result, in the water-refrigerant heat exchanger 2, the high-temperature refrigerant flowing in the refrigerant heat transfer tubes 2a and 2b and the water flowing in the feed water heat transfer tubes 2e and 2f exchange heat, the refrigerant dissipates heat, and the water is heated. . The radiated refrigerant is decompressed by the decompression devices 3a and 3b, and further expanded and evaporated by the evaporators 4a and 4b to become a gaseous state and return to the compressors 1a and 1b again. By continuing this heat pump operation, water passing through the water-refrigerant heat exchanger 2 is heated.
[0056]
In the tank hot water storage operation, the operation of the tank circulation pump 10 is started in the hot water storage circuit together with the heat pump operation, and the water drawn from the water inlet at the lower part of the auxiliary tank 9 is supplied to the tank circulation pump 10 and the water-refrigerant heat exchanger 2. Then, it circulates to the auxiliary tank 9 through the heat exchange flow rate adjustment valve 11 and the tank flow rate adjustment valve 12.
[0057]
As a result, the hot water heated by the water-refrigerant heat exchanger 2 is stored from the upper part of the auxiliary tank 9, and when the entire auxiliary tank 9 reaches the boiling state, it is determined that the hot water storage is completed (step 66), and the operation is started. Stop (step 67).
[0058]
In addition, the tank full determination is made by detecting a full water state using, for example, a water level sensor or a pressure sensor, and the hot water storage completion determination is made by detecting the water temperature in each of the upper, middle, and lower parts of the auxiliary tank 9 using, for example, a thermistor. It is. (Not shown)
FIG. 5 is an example of a flowchart showing the operation when hot water is used.
[0059]
When the faucet is opened at the tap terminal and hot water is used (step 70), the operation control means 50 activates the compressors 1a and 1b to start the operation of the heat pump circuit 30, and the water supply fitting 6, pressure reducing valve 7, and bypass. An instantaneous hot water supply operation (step 71) is performed by the hot water supply circuit of the valve 8, the water supply check valve 23, the water-refrigerant heat exchanger 2, the heat exchange flow rate adjustment valve 11, and the hot metal fitting 13. At the same time, the tank hot water supply operation is performed by the hot water supply circuit of the water supply fitting 6, the pressure reducing valve 7, the bypass valve 8, the hot water storage tank 9, the tank flow rate adjusting valve 12, and the hot metal fitting 13 (step 77).
[0060]
Here, the heat pump refrigerant circuit 30 sends the high-temperature refrigerant compressed by the compressors 1a and 1b to the water-refrigerant heat exchanger 2, heats the water flowing in from the water supply pipe 2c, and flows out to the hot water supply pipe 2d. At the start of operation, the refrigerant sent to the water-refrigerant heat exchanger 2 is sufficiently hot and high in pressure, and the temperature is low, and the water-refrigerant heat exchanger 2 as a whole is cooled. Is not enough. As the time elapses, the refrigerant becomes high temperature and pressure, and the heat generated by the condensed refrigerant is increased accordingly, and the ability to heat water increases.
[0061]
However, it usually takes about 5 to 6 minutes for the heating capacity of the heat pump operation to reach a high temperature stable state. Therefore, the operation control means 50 controls the operation by setting the rotation speed of the compressor at a higher speed than usual until the high temperature stable state is reached immediately after the start of operation, and the water heat transfer pipe described above is placed in the water-refrigerant heat exchanger 2. In this embodiment, the rise time can be reduced to about 1 to 2 minutes due to the synergistic effect of providing a plurality of paths in parallel. Further, the auxiliary tank for storing hot water required until the heat pump circuit is stabilized can be sufficiently miniaturized, and an instantaneous hot water supply system using a heat pump can be realized.
[0062]
Then, after performing a tank hot water supply operation for supplying hot water from the auxiliary tank for a predetermined time immediately after the start of operation (about 1 to 2 minutes), the operation control means 50 operates to stop the tank hot water supply operation, and instantaneous hot water supply Only operation is switched (steps 72, 78, 79). The determination of the tank hot water supply in step 78 may be made based on the temperature of the hot water actually flowing through the hot water supply pipe 2d in addition to measuring the operation time of the heat pump circuit.
[0063]
In this way, hot water is transiently supplied from the auxiliary tank 9 only at the start of operation, and then hot water heated by the water-refrigerant heat exchanger 2 is directly supplied, so that the heating delay at the start of operation can be eliminated. The capacity of the auxiliary tank 9 can be significantly reduced compared to the conventional case. It is to be noted that the capacity of the auxiliary tank 9 can be shortened by increasing the heating capacity of the water-refrigerant heat exchanger 2 to a stable state as quickly as possible and shortening the time of the transient tank hot water operation using the hot water of the auxiliary tank 9. Will lead to a further reduction in the size.
[0064]
For this purpose, it is desirable to increase the capacity of the heat pump refrigerant circuit 30, particularly the compressor output, to about 15 kW, which is about three times higher than the generally used 5 kW, but it is only necessary to develop a new compressor. However, each part of the heat pump refrigerant circuit 30 needs to be newly studied, which is extremely difficult. Therefore, in one embodiment of the present invention, as described above, a two-cycle heat pump system using two compressors is used, and the reliability of the conventional technology and the results are ensured.
[0065]
The operation control means 50 stops the tank hot water supply operation when the amount of remaining hot water in the auxiliary tank 9 becomes a predetermined value or less, and makes only the instantaneous hot water supply operation (steps 78 and 79).
[0066]
Next, when the hot water supply is finished and the faucet of the hot water supply terminal is closed (step 80), if the tank hot water supply operation and the heat pump hot water supply operation are performed immediately after the hot water is used, both the heat pump hot water supply operation and the tank hot water supply operation are performed. To stop. If the tank hot water supply operation is stopped and only the heat pump hot water supply operation is performed, the instantaneous hot water supply operation is stopped. (Steps 73 and 79)
Further, after stopping both the hot water supply operation of the tank and the hot water supply operation of the heat pump, the operation control means 50 always starts the hot water storage operation of the tank (step 74), detects the completion of the hot water storage using a thermistor and the like and determines the completion of the hot water storage (step 75). The operation is terminated (step 76).
[0067]
However, because the thermistor detects the state of hot water storage in the tank at all times, if the hot water temperature and the amount of water remain in the auxiliary tank almost the same as the hot water storage completion status even after the heat pump hot water operation is stopped, the hot water storage It is determined that the tank is hot and the tank hot water storage operation is not performed.
[0068]
According to the above, the operation control means 50 has a hot water storage operation function every time the hot water storage operation is performed until the hot water storage is completed after the intended operation is completed in every operation. The hot water of a predetermined temperature is full, so that the fear of a drop in hot water at the start of operation and running out of hot water during use can be solved.
[0069]
FIG. 6 is a flowchart showing an embodiment of a hot water filling operation by automatic bath operation. The bath automatic button is pressed and turned on (step 85). When the set time comes, the tank hot water supply operation (step 92) is performed simultaneously with the bath hot water supply operation (step 87). In the bath hot water supply operation, the heat pump hot water supply operation described in FIG.
[0070]
That is, for about 2 minutes immediately after the start of the heat pump operation, the bath hot water operation and the tank hot water storage operation are performed at the same time. It becomes only. Further, during the bath water supply operation, the bath hot water temperature and the amount of hot water in the bathtub are continuously detected, and the bath water supply operation is stopped when hot water at a predetermined temperature reaches the predetermined amount in the bathtub. (Steps 89, 90, 91)
FIG. 7 is a flowchart showing an embodiment of bath remedy by automatic bath operation. When the bath automatic button is pressed and turned on (step 95), the hot water temperature and the hot water amount in the bathtub are detected every predetermined time (for example, 30 minutes) after the hot water supply to the bath (step 96). If the value is out of the value, the bath chasing operation (step 97) is performed, and the bath operation is stopped by setting the hot water temperature and the hot water amount within predetermined values. (Steps 98 to 101)
As described above, according to each embodiment of the present invention, the water-refrigerant heat exchanger and the bath water-water heat exchanger are separated, and the hot water supply circuit from the water-refrigerant heat exchanger to the outlet terminal is made independent. As a result, it was possible to heat and discharge hot water with a heat pump with little heat loss.
[0071]
In addition, by separating the water-refrigerant heat exchanger and the bath heat exchanger, each of the water-refrigerant heat exchanger and the bath heat exchanger can have an optimum structure. Improving the start-up characteristics, enabling the instantaneous hot water supply system that operates only when necessary and supplies only the required amount of hot water with the heat pump circuit, and achieves the effects of drastic downsizing of the hot water storage tank, energy saving, etc. I was able to.
[0072]
Also, by installing a water on / off valve that connects to the heat exchanger for the bath at the branch that is not on the hot water supply circuit from the water-refrigerant heat exchanger to the hot water outlet terminal, Heat loss to the bath heat exchanger can be prevented.
[0073]
【The invention's effect】
  According to the present invention, energy savingNeAn excellent heat pump water heater can be provided.
[0074]
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an embodiment of a schematic configuration of a heat pump refrigerant circuit, a hot water storage circuit, and components in a heat pump water heater of the present invention.
FIG. 2 is a structural diagram of a water-refrigerant heat exchanger showing an embodiment of the present invention.
FIG. 3 is a structural diagram of a heat exchanger for baths showing an embodiment of the present invention.
FIG. 4 is a flowchart showing an embodiment of the operation at the time of installation and boiling of the auxiliary tank in the heat pump water heater of the present invention.
FIG. 5 is a flowchart showing an embodiment of an operation when hot water is used in the heat pump water heater of the present invention.
FIG. 6 is a flowchart showing an embodiment of an operation at the time of bathing and bathing in the heat pump water heater of the present invention.
FIG. 7 is a flowchart showing an embodiment of bath remedy by automatic bath operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1a, 1b ... Compressor 2 ... Water-refrigerant heat exchanger 2a, 2b ... Refrigerant heat transfer pipe 2c ... Water supply pipe 2d ... Hot water supply pipe 2e, 2f ... Water supply heat transfer pipe 3a, 3b ... Pressure reducing device 4a, 4b ... Evaporator 5a, 5b ... Solenoid valve for defrosting 6 ... Water supply fitting 7 ... Pressure reducing valve 8 ... Bypass valve 9 ... Auxiliary tank 10 ... Tank circulation pump 11 ... Heat exchange flow rate adjustment valve 12 ... Tank flow rate adjustment valve 13 ... Hot metal fitting 14 ... Bath pouring Valve 15 ... Bath sensor fitting 16 ... Bath bath fitting 17 ... Bath bath fitting 18 ... Bathroom 19 ... Bath circulation pump 20 ... Bath heat exchanger 20a ... Hot water heating pipe 20b ... Bath water heat transfer pipe 21 ... Water open / close valve 22 ... Bath reverse Stop valve 22 ... Water supply check valve 24 ... Relief valve 30 ... Heat pump refrigerant circuit 40 ... Hot water supply circuit 50 ... Operation control means 51 ... Kitchen remote control 52 ... Bath remote control

Claims (6)

A compressor, a water-refrigerant heat exchanger that exchanges heat between the refrigerant compressed by the compressor and water, a decompression device that decompresses the heat-exchanged refrigerant, and heat exchange between the decompressed refrigerant and air An evaporator for performing a heat pump refrigerant circuit respectively connected by a refrigerant line;
An instantaneous hot water supply circuit that heats water supplied from a water supply unit by the water- refrigerant heat exchanger and instantaneously supplies the heated hot water to a hot water outlet terminal;
After the start of operation of the instantaneous hot water supply circuit, an auxiliary tank that transiently assists hot water supply from the instantaneous hot water circuit,
A water-water heat exchanger for reheating a bath connected to a branch pipe branched from the instantaneous hot water supply circuit;
A water on-off valve disposed between the instantaneous hot water supply circuit and the water-water heat exchanger on the branch pipe;
The water on- off valve is a heat pump water heater that is closed when the hot water supply circuit is used to instantaneously supply water to the outlet terminal . A circulation pump for sending hot water of the water-water heat exchanger to the water-refrigerant heat exchanger;
Before Kisui - heat pump hot water supply apparatus according to claim 1, wherein for driving the circulation pump by opening the water-off valve in the case of performing the reheating bath water heat exchanger. A circulation pump for sending hot water in the auxiliary tank to the water-refrigerant heat exchanger;
A tank flow rate adjusting valve disposed between the auxiliary tank on the second branch pipe branched from the instantaneous hot water supply circuit ,
2. The heat pump water heater according to claim 1, wherein when the tank is reheated to warm the water in the auxiliary tank, the tank flow rate control valve is opened to drive the circulation pump. A flow rate adjusting valve is provided in the instantaneous hot water supply circuit and downstream of the water-refrigerant heat exchanger, and the flow rate adjusting valve is operated when the hot water from the auxiliary tank is mixed and discharged from the hot water terminal. Item 4. The heat pump water heater according to any one of Items 1 to 3 .   The heat-pump water heater according to claim 1, wherein the water-water heat exchanger has a double pipe structure including a heat transfer pipe inside a cylindrical pipe.   The heat pump water heater according to claim 1, wherein the heat pump refrigerant circuit includes two refrigeration cycles and shares the water-refrigerant heat exchanger.

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