JP3909312B2 - Heat pump water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat pump water heater, and more particularly to an instantaneous heat pump water heater that discharges water directly from a heat pump hot water supply circuit.
[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. It was common to use hot water during the day.
[0003]
However, in the above hot water supply 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, when using a bath, it is necessary to make a memorial by cooling the hot water after filling the bathtub. However, the conventional hot water supply system has only a one-sided hot water function from the hot water storage tank, so it can respond appropriately. There wasn't.
[0005]
As a measure for improving the above, there has been proposed a memorial function added. One such heat pump water heater is disclosed in Japanese Patent Laid-Open No. 2002-106963 (Patent Document 1).
[0006]
The conventional heat pump water heater of Patent Document 1 stores a large amount of hot water in a hot water storage tank so that hot water storage, hot water supply, hot water filling of a bath, and bath renewal operation can be performed by one unit. That is, the conventional heat pump water heater performs heat pump operation at night to store hot water in a hot water storage tank, and then does not perform heat pump operation. The water supply for the place and kitchen was provided.
[0007]
Therefore, a large hot water storage tank having 300 to 450 L is used. In addition, since the hot water storage temperature is higher, it can be diluted with water and used in a large amount. Therefore, the hot water is stored at a high temperature of 90 ° C. using a CO 2 refrigerant.
[0008]
[Patent Document 1]
JP 2002-106963 A
[0009]
[Problems to be solved by the invention]
As described above, the conventional heat pump type hot water heater requires a large-capacity hot water storage tank, and sufficient installation space and installation floor surface are required. In other words, considering the case where 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 carried out to ensure sufficient strength, and apartments and apartments It is difficult to install in a confined place such as a veranda in the country or in a place where the strength is insufficient, and furthermore, it takes a lot of cost and labor to transport the heat pump water heater to the customer's installation place. there were.
[0010]
In addition, conventional heat pump water heaters operate at night by using a discounted electricity charge at night, store hot water in hot water storage tanks and store hot water in hot water storage tanks during the day without heat pump operation. The usage is to use.
[0011]
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. In addition, because a large amount of hot water at a temperature higher than the ambient temperature is stored for a long time, heat is dissipated from the large surface of the hot water storage tank, resulting in wasted energy, so that the temperature drop can be warmed up at night. It was necessary to keep.
[0012]
That is, although the conventional heat pump water heater has the cost merit due to the night discount fee, there are still problems in terms of energy saving and global warming.
[0013]
The purpose of the present invention is small and light, excellent in transportability and installation, and boiled as much water as necessary when necessary, and used before the water is cooled. Excellent energy saving and prevention of global warming. It is to provide a heat pump water heater.
[0014]
Other objects and features of the present invention will become apparent from the following description.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, the heat pump water heater of the present invention uses tap water in the auxiliary tank in the auxiliary tank hot water circuit by warming tap water in the water-refrigerant heat exchanger of the heat pump refrigerant circuit at the time of hot water as much as possible. Thus, only the initial operation in which the water-refrigerant heat exchanger temperature of the heat pump refrigerant circuit does not increase is used.
[0016]
That is, the heat pump water heater of the present invention is A compressor, a water-refrigerant heat exchanger that exchanges heat between the refrigerant compressed by the compressor and the supplied water, a decompression device that decompresses the heat-exchanged refrigerant, and the decompressed refrigerant and air. A heat pump refrigerant circuit in which an evaporator for performing heat exchange is connected by a refrigerant pipe, water amount detection means for detecting the amount of supplied water, and heating the supplied water by the water-refrigerant heat exchanger A hot water supply circuit for instantaneous hot water supply capable of directly supplying hot water to the faucet via a hot water connector, and an auxiliary tank storing hot water for assisting the direct hot water supply. A heat pump hot water supply device for discharging hot water in the auxiliary tank when the amount of the supplied water is smaller than a predetermined amount when the hot water is discharged from the hot water connector. Thus, the object is achieved.
[0017]
In this way, the refrigerant circuit (the refrigeration cycle including the compressor) that consumes the most power in the hot water supply system does not have to be operated every time there is a small amount of hot water to save energy and prevent global warming. It is intended to be illustrated.
[0018]
The heat pump water heater of the present invention is A compressor, a water-refrigerant heat exchanger that exchanges heat between the refrigerant compressed by the compressor and the supplied water, a decompression device that decompresses the heat-exchanged refrigerant, and the decompressed refrigerant and air. A heat pump refrigerant circuit in which an evaporator for performing heat exchange is connected by a refrigerant pipe, water amount detection means for detecting the amount of supplied water, and heating the supplied water by the water-refrigerant heat exchanger A hot water supply circuit for instantaneous hot water supply capable of directly supplying hot water to the faucet via a hot water connector, and an auxiliary tank storing hot water for assisting the direct hot water supply. The heat pump water heater is configured to operate the heat pump refrigerant circuit when the amount of the supplied water exceeds a predetermined amount when the hot water is discharged from the hot water connector. Thus, the object is achieved.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS.
[0020]
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.
[0021]
The heat pump refrigerant circuit 30 includes two refrigeration cycles. In each cycle, the compressors 1a and 1b, the water-refrigerant heat exchangers 2a and 2b, the decompression devices 3a and 3b, and the evaporators 4a and 4b are sequentially connected via the refrigerant pipes. A refrigerant is sealed inside.
[0022]
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.
[0023]
The water-refrigerant heat exchanger 2 includes refrigerant side heat transfer tubes 2a and 2b and water supply side heat transfer tubes 2e and 2f. 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.
[0024]
The evaporators 4a and 4b are air refrigerant heat exchangers that exchange heat between air and refrigerant.
[0025]
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.
[0026]
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.
[0027]
The heat pump hot water supply circuit is a main hot water supply circuit of the heat pump water heater of this embodiment. Water from a water supply source taken in from a water supply connector (water supply connector) 6 which is a connection port with the water supply is decompressed by a pressure reducing valve 7 and sent to a water supply amount sensor 8. The water that has passed through the feed water check valve 23 from the feed water amount sensor 8 is warmed by the feed water heat transfer tubes 2e and 2f via the feed water piping 2c. The warmed water passes through the hot water supply pipe 2d through the heat exchange flow rate adjusting valve 11 in the middle, and the temperature of the water is monitored by the mixed temperature adjusting thermistor 53. To do. Each configuration is sequentially connected through a water pipe.
[0028]
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.
[0029]
Specifically, the hot water stored in the auxiliary tank 9 flows into the hot water supply pipe 2d through the branch pipe 2h when the tank flow rate adjustment valve 12 is opened, passes through the mixed temperature adjustment thermistor 53, and then passes through the hot water connection fitting 6. To do. At this time, the warm water is sent out from the auxiliary tank 9 when the clean water supplied through the water supply connector (water supply connector) 6 (water from the water supply source) is supplied through the pressure reducing valve 7 and the water supply amount sensor valve 8. It is because it is inject | poured into the auxiliary tank 9 with the water pressure adjusted through piping.
[0030]
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.
[0031]
In addition, since the tank circulation pump 10 operates during the hot water storage operation, the hot water that has passed through the heat AC amount adjusting valve 11 tends to enter the bath heat exchanger through the water opening / closing valve 21. A memorial check valve 55 prevents this. If the follow-up check valve 55 is not provided, the water on / off valve 21 must be completely sealed. However, this is difficult to achieve with current commercial products. Therefore, a memorial check valve 55 is provided. This valve 55 causes a short circuit between the bath heat exchanger 20 and the water / refrigerant heat exchanger 2 to prevent heat loss.
[0032]
The bath hot water supply circuit for supplying hot water to the bathtub is basically the same as 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 that passes through the bath sensor fitting 15 and is connected to the bath outlet connector 16. Of course, when hot water is filled in the bathtub 18, the auxiliary tank hot water supply from the auxiliary tank 9 to the bathtub 18 within the range where the amount of hot water in the auxiliary tank 9 does not fall below the minimum required amount together with the direct hot water supply from the water-refrigerant heat exchanger 2. To do.
[0033]
When the bath is filled with water, when the temperature of the refrigerant side heat transfer tubes 2a, 2b does not rise sufficiently, such as when the refrigeration cycle starts up or when the ambient temperature is low, the temperature of the water supply side heat transfer tubes 2e, 2f reaches the set value. There are times when I don't. At this time, along with the direct hot water supply by the bath hot water filling circuit, the auxiliary tank hot water is supplied from the auxiliary tank 9 to the bathtub 18 within a range where the amount of hot water in the auxiliary tank 9 does not become the minimum required amount or less.
[0034]
This is determined by the mixing temperature adjusting thermistor 53. That is, based on the detection result of the mixed temperature adjusting thermistor 53, the operation control means 50 gives an instruction to the thermal AC amount adjusting valve 11 and the tank flow rate adjusting valve 12, and for example, the set temperature is 43 ° C. When the temperature of the hot water passing through 11 is 35 ° C., the thermal AC regulating valve 11 is throttled and the tank flow rate regulating valve 12 is opened, for example, a large amount of hot water of 65 ° C. in the auxiliary tank 9 is taken out to the bathtub 18 as hot water of 43 ° C. Hot water is to be supplied.
[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. The water drawn from the bathtub 18 through the hot-water hot-water connection fitting (hot-water hot-water connection fitting) 17 by the bath circulation pump 19 is sent to the bath heat transfer pipe 20b and heated by heat exchange, and passes through the bath sensor metal fitting 15. After the temperature of the hot water is measured, the hot water is supplied to the bathtub 18 through the bath hot water connector (outlet hot water connector) 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. Hot water supplied to the bathtub 18 is detected by the bath sensor fitting 15, the temperature of water stored in the auxiliary tank 9 is detected by the temperature sensor (A, B, C), or hot water is discharged from the mixed temperature adjusting thermistor 53. A temperature sensor that detects the temperature of water heated by the water-refrigerant heat exchanger 2 and other parts as well as a pressure sensor that detects the discharge pressure of the compressors 1a and 2b, A water level sensor or the like (not shown) for detecting the water level in the bathtub 17 is provided, and each detection signal is 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. In addition, it is difficult for the commercially available water on-off valve 21 to completely close the water circuit. In this embodiment, a memorial check valve 55 is provided to prevent this.
[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, 2b and two water supply heat transfer tubes 2e, 2f. The refrigerant heat transfer tubes 2a, 2b and the water supply electric heat tubes 2e, 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]
That is, in the present invention, the double bath structure is adopted by separating the heat exchanger 20 for bath remedy from the water-refrigerant heat exchanger 2 and performing water-water heat exchange between the heated circulating water and the bath circulating water. Is now possible.
[0049]
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.
[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 the branch pipe 2i side, which is the side of the hot water connector 13 is closed. 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. The valve 14 is closed.
[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 performed 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 performed on the auxiliary tank 9 using a thermistor (temperature sensors (A, B, C)). The water temperature of each lower part is detected and determined.
[0059]
FIG. 5 is an example of a flowchart showing the operation when hot water is used.
[0060]
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, the pressure reducing valve 7, and the 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 water connector 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 water connector 13 (step 77).
[0061]
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, since the refrigerant sent to the water-refrigerant heat exchanger 2 is sufficiently hot and high in pressure, the temperature is low, and the water-refrigerant heat exchanger 2 as a whole is cooled, so that the heating ability to heat water 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.
[0062]
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.
[0063]
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.
[0064]
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.
[0065]
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.
[0066]
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).
[0067]
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 tank hot water supply operation and the heat pump hot water supply operation, the operation control means 50 always starts the tank hot water storage operation (step 74), and detects the completion of the hot water storage using a temperature sensor (A, B, C), thermistor, etc. After completion of hot water storage is determined (step 75), the operation is terminated (step 76). .
[0068]
However, the detection of the tank hot water storage state by the thermistor is always performed, and the hot water temperature and the amount of hot water remain in the auxiliary tank almost equal to the hot water storage completion state even after the heat pump hot water operation is stopped because it is used for an extremely short time (described later). In the case of face washing and hand washing), it is determined that the hot water storage is completed, and the tank hot water storage operation is not performed.
[0069]
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.
[0070]
The operation of the heat pump water heater at the time of face washing, hand washing, etc., in which, for example, 1.5 L or less of hot water is consumed from a faucet (not shown) connected to the end of the hot water connector (hot water connector) 13 Is as shown by the thick solid line in FIG.
[0071]
That is, when the amount of hot water supply is small, the heat pump refrigerant circuit 30 is basically not operated by using hot water in the auxiliary tank 9. This is because even when a small amount is consumed, power consumption increases when the heat pump refrigerant circuit 30 is operated.
[0072]
Regarding the operation, when the faucet (not shown) connected to the tip of the hot water connector 13 is first opened, the hot water in the auxiliary tank 9 is subjected to the water pressure of the water supply, so that it passes through the tank flow rate adjustment valve 12. Hot water is poured out. At this time, the amount of water consumed in the auxiliary tank 9 is replenished although it is slightly smaller than that of the water supply source. Of course, the water supplied from this water supply source is first adjusted to a water pressure of 160 kpa by the pressure reducing check valve 7 and reaches the water supply amount sensor 8. Here, a sensor having a structure to be described later confirms, for example, whether or not a flow rate of 1.5 L or less per minute is consumed based on the amount of water supplied from the water supply source. If the amount of water of 1.5 L / min or more passes here, the operation control means 50 that has detected the signal from the feed water amount sensor 8 instructs the operation of the heat pump refrigerant circuit 30. In this case, the operation of the heat pump refrigerant circuit 30 is not performed because the amount of water that has passed through the feed water amount sensor 8 is 1.5 L / min or less, but this amount of water is a numerical value that is appropriately determined.
[0073]
Accordingly, the water that has turned to the water refrigerant heat exchanger 2 side as shown by the thick dotted line in FIG. 6 is simply a water pipe and passes through the water refrigerant heat exchanger 2 because the water refrigerant heat exchanger 2 is stopped. In the state (tap water), it passes through the heat exchange amount adjusting valve 11 and is discharged to the hot water connector 13 side along with hot water coming from the auxiliary tank 9 side.
[0074]
At this time, the thermal AC amount adjusting valve 11 and the tank flow rate adjusting valve 12 adjust the opening degree of the valve to adjust the amount of water or hot water coming from each. In order to execute this adjustment control, the detection result of the mixed temperature adjustment thermistor 53 is required. That is, based on the detection result of the mixed temperature adjustment thermistor 53, control is performed to throttle the heat AC amount adjustment valve 11 through which water flows when hot water having a high set temperature is discharged, and to throttle the tank flow rate adjustment valve 12 when hot water having a low set temperature is discharged. To do.
[0075]
When a large amount of water from the water supply source enters the auxiliary tank 9 and the temperature of the water at the bottom of the auxiliary tank 9 is detected to be, for example, 50 ° C. or less from the detection result of the temperature sensor A, the operation control means 50 In consideration of other operating conditions, in order to warm 50 ° C. hot water in the auxiliary tank 9, the tank circulation pump 10 is operated and the tank hot water storage operation by the water / refrigerant heat exchanger 2 is executed. Control to keep the temperature at the set temperature.
[0076]
7 and 8 show a specific structure of the water supply amount sensor in the present embodiment. When water flows in the direction of arrow H (auxiliary tank 9 side), the feed water amount sensor 8 detects the amount of water between the magnet 8b that the propeller 8a rotates and the hall element 8c (attached to the main body side). A pulse signal corresponding to the number of revolutions, that is, a configuration in which a signal group of one pulse is sent to the operation control means 50 by one rotation of the propeller 8a, and the operation control means 50 detects the amount of water per unit time. A bypass valve 54 is connected in the direction of arrow I. The bypass valve 54 is a proportional valve capable of distributing water to the branch pipe 2i in order to adjust the temperature of the hot water discharged from the feed water amount sensor 8. The bypass valve 54 is opened when the temperature of the hot water discharged through the hot-water supply connector 13 is high and hot water from the water supply source is added to lower the temperature of the hot water. The instruction to open the bypass valve 54 is executed by the operation control means 50 according to a detection result of a thermistor or the like provided near the hot water connector 13 (not shown).
[0077]
A temperature sensor attached to the auxiliary tank 9 in FIG. B. For example, the temperature sensor A is mounted at a position 200 mm from the bottom of the auxiliary tank, the temperature sensor B is mounted at the center of the auxiliary tank, and the temperature sensor C is mounted at a position 200 mm from the top of the auxiliary tank. When the temperature in the auxiliary tank 9 falls below the set value, the tank circulating pump 10 is operated and the water / refrigerant heat exchanger 2 is operated, and the tank hot water storage operation is started to warm up to the set value.
[0078]
Further, the flow rate of water flowing per unit time may be detected by the feed water amount sensor 8, and the compressors 1a and 1b in the heat pump refrigerant circuit may be operated. However, the accumulated flow rate per unit time is detected from the feed water amount sensor 8. It goes without saying that the operation control means 50 may be controlled so as to operate the compressors 1a and 1b, calculated from the results. Further, the water supply amount sensor 8 may be added with a thermistor or the like to measure the water temperature from the water supply source and vary the rotation speed of the compressor. That is, when the temperature of the supplied water is low, the control may be corrected so as to increase the rotational speed of the compressor.
[0079]
【The invention's effect】
As described above, according to the present invention, a heat pump water heater that can contribute to energy saving and prevention of global warming can be provided.
[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 operations during installation and boiling of the auxiliary tank in the heat pump water heater of one embodiment of the present invention.
FIG. 5 is a flowchart showing an operation when hot water is used in the heat pump water heater of one embodiment of the present invention.
FIG. 6 is a diagram showing a flow from water supply to tapping when the amount of tapping is small in the schematic diagram of FIG.
FIG. 7 is a partial cross-sectional front view of a water supply amount sensor used in an example of the present invention.
8 is a partial cross-sectional side view of FIG. 7;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1a, 1b ... Compressor 2 ... Water-refrigerant heat exchanger 2a, 2b ... Refrigerant side heat transfer pipe 2c ... Water supply pipe 2d ... Hot water supply pipe 2e, 2f ... Water supply side heat transfer pipe 3a, 3b ... Pressure-reducing device 4a, 4b ... Evaporator 5a , 5b ... Solenoid valve for defrosting 6 ... Feed water connector 7 ... Pressure reducing valve 8 ... Feed water sensor 9 ... Auxiliary tank 10 ... Tank circulation pump 11 ... Heat AC amount regulating valve 12 ... Tank flow rate regulating valve 13 ... Outlet connector ( 14 ... Bath pouring valve 15 ... Bath sensor fitting 16 ... Bath hot spring connection tool (hot spring connection fitting) 17 ... Bathing hot water connection tool (hot spring connection fitting) 18 ... Bathtub 19 ... Bath circulation pump 20 ... Bath heat exchange 20a ... Hot water electric heat pipe 20b ... Bath water heat transfer pipe 21 ... Water on / off valve 22 ... Bath check 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 Mocon 52 ... bath remote controller 53 ... mixing temperature adjusting thermistor 54 ... bypass valve 55 ... add 焚逆 stop valve A. B. C: Temperature sensor.

Claims (5)

A compressor, a water-refrigerant heat exchanger that exchanges heat between the refrigerant compressed by the compressor and the supplied water, a decompression device that decompresses the heat-exchanged refrigerant, and the decompressed refrigerant and air. A heat pump refrigerant circuit in which an evaporator for performing heat exchange of each is connected by a refrigerant pipe,
Water amount detecting means for detecting the amount of supplied water;
The supplied water before Kisui - the hot water heated by the refrigerant heat exchanger, the hot water, and hot water supply circuit for instant water heater that can be directly hot water to the faucet through a tapping fitting,
In order to assist the direct hot water supply, an auxiliary tank storing hot water,
A heat pump water heater equipped with
Wherein the tapping fitting or RaIzuru water to Rutoki, heat pump water heater for tapping hot water in the auxiliary tank when the water supply amount of water is less than a predetermined amount. A compressor, a water-refrigerant heat exchanger that exchanges heat between the refrigerant compressed by the compressor and the supplied water, a decompression device that decompresses the heat-exchanged refrigerant, and the decompressed refrigerant and air. A heat pump refrigerant circuit in which an evaporator for performing heat exchange of each is connected by a refrigerant pipe,
Water amount detecting means for detecting the amount of supplied water;
The supplied water before Kisui - the hot water heated by the refrigerant heat exchanger, the hot water, and hot water supply circuit for instant water heater that can be directly hot water to the faucet through a tapping fitting,
In order to assist the direct hot water supply, an auxiliary tank storing hot water,
A heat pump water heater equipped with
Wherein the tapping fitting or RaIzuru water to Rutoki, heat pump water heater for operating the heat pump refrigerant circuit when the water supply amount of water exceeds a predetermined amount. A compressor, a water-refrigerant heat exchanger for exchanging heat between the refrigerant compressed by the compressor and water supplied via a water supply connector, a decompressor for decompressing the heat-exchanged refrigerant, and a decompressor A heat pump refrigerant circuit in which an evaporator that performs heat exchange between the generated refrigerant and air is connected by a refrigerant pipe,
Water amount detecting means for detecting the amount of supplied water;
The supplied water before Kisui - the hot water heated by the refrigerant heat exchanger, the hot water, and hot water supply circuit for instant water heater that can be directly hot water to the faucet through a tapping fitting,
In order to assist the direct hot water supply, an auxiliary tank storing hot water,
A heat pump water heater equipped with
The tapping fitting or RaIzuru water to Rutoki, wherein when the water supply amount of water is less than the predetermined amount is tapped hot water in the auxiliary tank, operating the heat pump refrigerant circuit when the water supply amount of water exceeds a predetermined amount Heat pump water heater. The amount of water receiving the output from the detection means, the water supply amount of water in the heat pump water heater according to claim 2 or 3, wherein with the operation control means for controlling the operation start and operation stop of the heat pump refrigerant circuit based. 5. The water amount detection unit according to claim 1, wherein a magnet is attached to a propeller side that rotates with flowing water, and the rotation speed of the propeller is detected as a pulse signal between hall elements provided on the main body side . The heat pump water heater according to item 1 .

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