JP2003161545A - Heat pump type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump type water heater that operates with high COP irrespective of the season and prevents occurrence of a hot water outage. <P>SOLUTION: The heat pump type water heater comprises a heat pump unit 2 and a tank unit 3 having a hot water storage tank 3 for storing warm water heated in the heat pump unit 2. The frequency of a compressor 25 in the heat pump unit 2 and a fan air capacity of an evaporator 28 in the heat pump unit 2 are varied according to the season to provide operation control of boiling water of a given heat capacity within a given time. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type hot water supply device.

[0002]

2. Description of the Related Art Generally, a heat pump type hot water supply apparatus includes a tank unit 71 having a hot water storage tank 70 and a heat source unit 73 having a refrigerant circuit 72, as shown in FIG. Further, the refrigerant circuit 72 is configured by connecting a compressor 74, a water heat exchanger 75, an expansion valve 77 and an evaporator 78 in this order. The tank unit 71 includes the hot water storage tank 70 and a circulation path 79, and a water circulation pump 80 and a heat exchange path 81 are provided in the circulation path 79.
In this case, the heat exchange passage 81 is composed of the water heat exchanger 75.

In the above apparatus, when the compressor 74 is driven and the pump 80 is driven (operated), stored water (hot water) flows out from the intake port provided at the bottom of the hot water storage tank 70 into the circulation path 79, This flows through the heat exchange passage 81.
At this time, this hot water is heated (boiling up) by the water heat exchanger 75 and returned to the upper part of the hot water storage tank 70 from the hot water inlet. As a result, high-temperature hot water is stored in the hot water storage tank 70. In addition, since the current power rate system is set so that the power rate unit price at midnight is lower than that at daytime, this operation is low at midnight hours (for example, 23 hours).
In many cases, the running cost is reduced during the period from 07:00 to 7:00). That is, hot water used in the daytime at midnight is stored in the hot water storage tank 70.
The so-called total boiling operation is carried out.

Further, the amount of hot water required varies depending on the season and the number of people used, and the amount of hot water in the hot water storage tank 70 boiled during the midnight time may be insufficient. It was necessary to perform the reheating operation A in which the water was heated in the daytime. Furthermore, if the set amount of hot water is being boiled, but is used more than the planned amount of hot water, the hot water in the hot water storage tank 70 will run out. In such a case, it is necessary to perform the reheating operation B in which the shortage is boiled in the daytime.

[0005]

Conventionally, the above-mentioned full boiling operation and the reheating operations A and B were all operated at the same setting. That is, the frequency of the compressor 74, the evaporator 7
The fan rotation speed of 8 and the rotation speed of the circulation pump 80 were the same. However, since the incoming water temperature (the temperature of the water flowing into the heat exchange passage 81), the fan rotation speed of the evaporator 78, and the hot water outlet temperature (the temperature of the hot water flowing out of the heat exchange passage 81) differ depending on the season, However, the COP could not be optimized by operating with the same settings.

In addition, in the above-described reheating operation B for preventing (avoiding) running out of hot water, although it is necessary to boil a predetermined amount of hot water in a short time, the operation is performed with the same settings as other operations. When I went there, I could not boil in a short time. Therefore, in this reheating operation B, there are cases where the hot water runs out in time.

The present invention has been made in order to solve the above-mentioned conventional drawbacks, and its purpose is to enable a high COP operation regardless of the season and to prevent hot water shortage. It is to provide a heat pump hot water supply device capable of performing the above.

[0008]

Therefore, the heat pump type hot water supply apparatus according to claim 1 comprises a heat pump unit 2 and a tank unit 1 having a hot water storage tank 3 for storing the hot water boiled by the heat pump unit 2. The heat pump hot water supply device is characterized by performing operation control for changing the frequency of the compressor 25 of the heat pump unit 2 according to the season so as to boil hot water having a predetermined heat capacity within a predetermined time.

In the heat pump type hot water supply device according to claim 1,
The frequency of the compressor 25 of the heat pump unit 2 is changed according to the season, and operation control is performed such that boiling water with a predetermined heat capacity is boiled within a predetermined time. That is, the frequency of the compressor 25 is set low in the summer when the outside air temperature is high and set high in the winter when the outside air temperature is low, thereby changing the capacity according to the season. This makes it possible to optimize the COP.

The heat pump type hot water supply apparatus according to a second aspect is characterized in that operation control is performed to change the fan air volume of the evaporator 28 of the heat pump unit 2 according to the season.

In the heat pump type hot water supply device according to claim 2,
The frequency of the compressor 25 and the fan air volume are changed according to the season, and operation control is performed such that boiling water having a predetermined heat capacity is boiled within a predetermined time. That is, in the summer when the outside air temperature is high, the frequency of the compressor 25 and the fan air flow rate are set low, and in the winter when the outside air temperature is low, the frequency and the fan air flow rate of the compressor 25 are set high, thereby improving the capacity according to the season. change. This makes it possible to further optimize the COP.

The heat pump hot water supply apparatus according to claim 3 is configured to secure the required amount of hot water by performing the boiling operation during the midnight time and the additional boiling operation during the daytime outside the midnight time. Both the boil-up operation and the additional boil-up operation are characterized in that the operation is controlled according to the season as described above.

In the heat pump hot water supply apparatus according to the third aspect, since the boiling operation at midnight and the additional boiling operation during the day are performed, the required hot water amount for one day exceeds the capacity of the hot water storage tank 3. Can also secure this required amount of hot water,
It is possible to prevent "out of water". Further, since the capacity of each operation is changed according to the season, the COP can be optimized.

In the heat pump type hot water supply apparatus according to the present invention, the frequency increasing operation for increasing the frequency of the compressor 25 above the frequency is performed at the time of reheating the shortage when the amount of hot water used exceeds the set required hot water amount. It is characterized by doing.

In the heat pump type hot water supply apparatus according to the fourth aspect, since the reheating is the frequency increasing operation for increasing the frequency, the boiling capacity is improved. Therefore, when boiling a certain amount of hot water to a predetermined temperature, the boiling time is shorter than the boiling time with normal capacity.

In the heat pump type hot water supply apparatus according to a fifth aspect of the present invention, when replenishing the shortage when the amount of hot water used exceeds the set required hot water amount, the fan air amount increasing operation is performed to increase the fan air amount above the fan air amount. It features.

In the heat pump type hot water supply apparatus according to the fifth aspect, since the air volume increasing operation for increasing the fan air quantity at the time of the reheating is performed, the capacity is improved. Therefore, the same as the heat pump type hot water supply apparatus according to the fourth aspect. , The reheating time is shortened.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, specific embodiments of the heat pump type hot water supply apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a simplified diagram of this heat pump type hot water supply device. This heat pump type hot water supply device comprises a tank unit 1 and a heat pump unit (heat source unit) 2, and water (hot water) in the tank unit 1 is heated by the heat pump unit 2. To do.

The tank unit 1 includes a hot water storage tank 3,
The hot water stored in the hot water storage tank 3 is supplied to a bath or the like (not shown). That is, the hot water storage tank 3 is provided with a water supply port 5 on its bottom wall and a hot water outlet 6 on its upper wall. Then, city water is supplied from the water supply port 5 to the hot water storage tank 3, and high-temperature hot water is discharged from the discharge port 6. Further, in the hot water storage tank 3, a water intake 10 is opened in the bottom wall thereof, and a hot water inlet 11 is opened in the upper part of the side wall (peripheral wall), so that the hot water intake 10 and the hot water inlet 11 are connected by a circulation path 12. Has been done. A water circulation pump 13 and a heat exchange passage 14 are provided in the circulation passage 12. A water supply channel 8 is connected to the water supply port 5.

By the way, in the hot water storage tank 3, five remaining hot water amount detectors 18a, 18b, 18 are arranged at a predetermined pitch in the vertical direction.
c, 18d, and 18e are provided. Each of the remaining hot water amount detectors 18a ... Is made of, for example, a thermistor. Further, in the circulation path 12, an intake thermistor 20 is provided on the upstream side of the heat exchange path 14, and a hot water outlet thermistor 21 is provided on the downstream side of the heat exchange path 14.

Next, the heat pump unit (heat source unit) 2 is provided with a refrigerant circuit, and this refrigerant circuit includes a compressor 25.
A water heat exchanger 26 constituting the heat exchange passage 14, an electric expansion valve (pressure reducing mechanism) 27, and an air heat exchanger (evaporator) 28.
It is configured by connecting and in order. That is, the discharge pipe 29 of the compressor 25 is connected to the water heat exchanger 26, and the water heat exchanger 26
To the electric expansion valve 27 via a refrigerant passage 30, the electric expansion valve 27 to an evaporator 28 via a refrigerant passage 31, and the evaporator 28 and the compressor 25 with an accumulator 32 interposed therebetween. It is connected through the passage 33. Accordingly, when the water heat exchanger 26 drives the compressor 25, the heat exchange passage 14
The water flowing through can be heated. A fan 34 is attached to the air heat exchanger 28.

By the way, as shown in FIG. 2, the control unit of this heat pump type hot water supply apparatus has the above-mentioned remaining hot water amount detectors 18 respectively.
Based on the detected value detected by the remaining hot water amount detecting means 39, the remaining hot water amount detecting means 39 configured by a, 18b, 18c, 18d, etc., the setting means 40 for setting the data of the following Table 1 and the like Correcting means 41 for correcting the frequency and the like of the compressor 25
And the control means 42 and the like to which the data of the remaining hot water amount detecting means 39 and the setting means 40 are input. The control means 42
Can be configured using, for example, a microcomputer.

[0023]

[Table 1]

In the heat pump type hot water supply device, the control means 4 is based on the numerical value set by the setting means 40.
At 2, the compressor 25 is operated while controlling it. This table 1
Then, divide one year into five, and sequentially set the frequency of the compressor 25 to 86H in order to have the highest frequency in winter and the lowest frequency in summer.
z, 74 Hz, 58 Hz, 44 Hz and 40 Hz. Then, when the frequency of the compressor 25 is 86 Hz, the fan rotation speed of the fan 34 of the air heat exchanger 28 is set to 550 r.
When the frequency of the compressor 25 is 74 Hz, the fan rotation speed is 500 rpm, and the frequency of the compressor 25 is 5 rpm.
The fan speed is set to 500 rpm at 8 Hz, and the fan speed is set to 50 when the frequency of the compressor 25 is 44 Hz.
When the frequency of the compressor 25 is 40 Hz, the fan rotation speed is 450 rpm. In this case, the discharge temperature (discharge pipe temperature) limit value at each stage is set to 120 ° C. to 110 ° C. as shown in Table 1.

Next, the normal operation control of the heat pump type hot water supply apparatus configured as described above will be described with reference to FIG. As shown in step S1, operation is performed at the frequency of the compressor 25 (normal value), the fan rotation speed (normal value), and the discharge temperature limit value (normal value) that are set according to each season. That is, the compressor 25 is driven and the water circulation pump 13 is driven (operated). Then, stored water (hot water) flows out from the water intake 10 provided at the bottom of the hot water storage tank 3, and this flows through the heat exchange passage 14 of the circulation passage 12. At this time, this hot water is heated (boiled) by the water heat exchanger 26 and returned from the hot water inlet 11 to the upper part of the hot water storage tank 3. By continuously performing such an operation, hot water is stored in the hot water storage tank 3.

Then, in step S2, it is determined whether or not the incoming water temperature (temperature of the intake thermistor 20) T6 is 60 ° C. or higher. If the temperature is 60 ° C. or higher, the temperature of the hot water from the lower part of the hot water storage tank 3 is 60 ° C. or higher. Therefore, it is determined that the hot water in the hot water storage tank 3 is boiling, and the process proceeds to step S3 to stop this operation. If the temperature is lower than 60 ° C. in step S2, it is determined that the hot water in the lower part of the hot water storage tank 3 has not boiled yet, and the process returns to step 1 to continue the normal boiling operation until boiling.

In this case, the operating condition (normal value) is changed for each season as shown in Table 1 above. Therefore, hot water having a predetermined heat capacity can be boiled within a predetermined time throughout the year. That is, in winter, since the water temperature is low, the frequency of the compressor 25 is increased to improve the capacity.
In the summer, the temperature of the incoming water is high, so the compressor 25 is operated at a low frequency. This makes it possible to optimize the COP regardless of the season.

By the way, as this operation, it is preferable to operate in the midnight time zone (from 23:00 to 7:00) shown in FIG. This is because the current electricity tariff system sets the unit price of electricity at midnight to be lower than that at daytime. However, even if the operation is performed as shown in the flow chart of FIG. 3, if the required hot water amount for one day does not boil in the late-night hours (if the hot water storage tank 3 capacity is exceeded), the daytime shown in FIG. It is necessary to perform an additional reheating operation (additional boiling operation) from 7:00 to 23:00. This additional boiling operation is also performed at the normal value according to each season (set value in Table 1, etc.).

Next, the daytime additional boiling operation will be described with reference to the flow chart of FIG. First, step S
In step 4, it is determined whether the temperature (T5) detected by the remaining hot water amount detector 18e is 45 ° C. or lower. If T5 is above 45 ° C, there is hot water above 45 ° C up to the bottom of the hot water storage tank 3, so there is no need to perform additional reheating operation, and if T5 is below 45 ° C. This is because the lower part of the hot water storage tank 3 has low-temperature hot water, and it is necessary to perform additional additional boiling operation. Therefore, if it is determined in step S4 that it is not necessary to perform the additional boiling operation, the additional boiling operation is waited for without additional reheating. If it is determined that the additional boiling operation is required, the process proceeds to step S5 and the additional boiling operation is started.

In this step S5, as in step S1 of FIG. 3, the compressor 2 set for each season is set.
The operation is performed at the frequency of 5 (normal value), the fan rotation speed (normal value), and the discharge temperature limit value (normal value). Next, step S
Then, the process proceeds to 6 to determine whether or not to finish the additional reheating operation. In this case, the water temperature (T6) entering the heat exchange passage 14 is detected by the water thermistor 20, and it is judged whether this temperature is a predetermined temperature or not, and a predetermined time (for example, 1 hour) set in advance is determined. Determine if it is finished.
That is, whether the water temperature (T6) exceeds 60 ° C,
Alternatively, if the additional operation time has ended, the process proceeds to step S7 to stop and end this operation. Further, if the incoming water temperature (T6) is less than 60 ° C. and the additional operation time has not ended, it is determined that this additional boiling operation is still necessary, and it is determined that the additional boiling operation has ended. Continue this additional boiling operation until.

As described above, when the hot water in the hot water storage tank 3 is used and reduced, and the additional boiling operation becomes possible, the additional boiling operation is performed, thereby ensuring the required amount of hot water for one day. Therefore, the hot water in the hot water storage tank 3 can be prevented from running out. Moreover, the hot water storage tank 3
When the hot water in the inside runs low, it will be replenished for that amount, and so-called "after-burning" operation will be performed, and it is possible to prevent useless extra-heating operation during the daytime when the fee is high.

By the way, as described above, the operation of only the midnight time period, or the operation of the midnight time period and the additional boiling operation is performed to bring up the required amount of hot water for one day. An unscheduled amount of hot water may be used, and in such a case, it is necessary to perform a reheating operation for replenishment, which is different from the additional boiling operation. Since this reheating operation is replenishment for unscheduled use, there is a risk of running out of hot water in the hot water storage tank 3 and causing "out of hot water" unless it is replenished in a short time.

Therefore, this reheating operation is operated according to the flow chart shown in FIG. In this reheating operation, first, in step S8, it is determined whether or not this reheating operation is necessary. In this case, the remaining hot water amount detector 18
It is determined whether the temperature (T1) detected in a is 45 ° C. or lower. That is, if this temperature (T1) is 45 ° C. or lower, the temperature of the hot water in the upper part of the hot water storage tank 3 is 45 ° C.
This is because the following low temperatures are in a state where there is no hot water to be used and it is necessary to reheat. Therefore, when the temperature (T1) exceeds 45 ° C. in step S8, it is determined that it is not necessary to perform the additional heating operation, and the additional heating operation is not performed until the additional heating operation is required. Then, in step S8, the temperature (T
If 1) determines that the reheating operation needs to be performed at 45 ° C. or less, the process proceeds to step S9 and the reheating operation is performed.

In this reheating operation, the correction means 41 is applied to the frequency (normal value) of the compressor 25, the fan speed (normal value), and the discharge temperature limit value (normal value) which are set according to each season. The operation is performed by adding the correction values 1, 2, and 3 set in. The frequency correction value 1 is 5 to 10 Hz, the fan rotation speed correction value 2 is 50 rpm, and the discharge temperature limit value correction value 3 is 10 ° C. This correction value 1,
The boiling capacity can be improved by adding a few. Therefore, when boiling a certain amount of hot water to a predetermined temperature, the correction values 1, 2, and
It is possible to shorten the operation time with a value obtained by adding 3.
That is, when the amount of hot water required for one day is used more than planned, this shortage can be replenished in a short time.

Next, the process proceeds to step S10, and it is judged whether or not this reheating operation is to be ended. That is, in step S10, it is determined whether the temperature (T1) is 60 ° C. or higher and whether this operation has been continued for a predetermined time (for example, 30 minutes). And the temperature (T1) is 60 ℃
If the above is the case and it continues for 30 minutes, it is determined that this reheating operation is stopped, the process proceeds to step S11, and the operation is stopped and ended. Also, the temperature (T1) is 6
If the temperature is below 0 ° C or does not continue for 30 minutes,
It is determined that it is not necessary to stop the reheating operation, and the reheating operation is continued until it is determined that the reheating operation is finished.

When the operation shown in the flow chart of FIG. 6 is carried out, the additional hot water can be boiled in a short time, and "out of hot water" where the hot water of a desired temperature cannot be secured during use is prevented. be able to. By the way, in the reheating operation of the flowchart shown in FIG. 6, the frequency increasing operation for increasing the frequency of the compressor 25 and the air volume increasing operation for increasing the fan air volume are performed. You may That is, it is possible to improve the boiling capacity even if either one of the increasing operations is performed, and it is possible to reduce the operation time of the reheating operation. However, if the frequency increasing operation and the air volume increasing operation are performed at the same time, a reliable capacity improvement can be achieved, a shortage of shortage can be quickly achieved, and "runout" can be avoided more reliably.

In the above-described embodiment, the total amount boiling operation shown in FIG. 3, the additional boiling operation shown in FIG. 5, and the additional heating operation shown in FIG. 6, the temperature T2 of the hot water amount detector 18b and the hot water amount detector 18c.
Although the temperature T3, the temperature T3 of the hot water amount detector 18d, the temperature T4 of the hot water amount detector 18e, the hot water discharge thermistor 21 and the like are not used, these may be used. By using these, the temperature distribution condition of the hot water storage tank 3 can be grasped with certainty, and the boiling operation, the additional boiling operation, and the reheating operation can be performed more finely, and the control of each operation is stable. To do.

Although the specific embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications can be carried out within the scope of the present invention. For example, the setting value (normal value) of the frequency of the compressor 25 for each season is not limited to that shown in Table 1. One year is divided into 6 or more or 4 or less ranges, and the range is set to each range. A corresponding normal value may be set. If a large range is set, finer control can be performed. Further, as the amount of increase in frequency during frequency increase operation (correction value 1) and the amount of increase in fan air flow during air volume increase operation (correction value 2), depending on the required additional heating amount, additional heating time, etc. Further, it can be arbitrarily increased or decreased according to each season or the like. Note that, in the additional boiling operation (additional operation in the daytime in order to secure the required required hot water amount), the frequency increasing operation or the air volume increasing operation may be performed if necessary.

[0039]

According to the heat pump type hot water supply apparatus of the first aspect, the capacity can be changed according to the season, and CO
It is possible to optimize P (high COP operation). That is, stable operation can be performed at a low running cost throughout the year, and the life of the device can be improved.

According to the heat pump type hot water supply apparatus of claim 2, the capacity can be changed with high accuracy according to the season, the COP can be optimized, and the running cost can be reduced throughout the year. Stable operation is possible, and the life of the device can be further improved.

According to the heat pump type hot water supply apparatus of claim 3, since the boiling operation at midnight time and the additional boiling operation for the shortage of the required hot water quantity during the daytime outside of this midnight time are performed, the required hot water quantity for one day is required. Even if the amount exceeds the capacity of the hot water storage tank, the required amount of hot water can be secured, and the occurrence of "out of hot water" can be prevented. As a result, the hot water can be stably supplied, and the user can spend comfortably. In addition, since the capacity of each operation is changed according to the season, stable operation can be performed at a low running cost throughout the year.

According to the heat pump type hot water supply device of the fourth or fifth aspect, the capacity is improved at the time of reheating the shortage when the amount of hot water used is larger than the set required amount of hot water.
This makes it possible to replenish this shortage in a short time when more than the preset daily hot water requirement is used, and to effectively prevent "out of hot water" due to this use. it can.

[Brief description of drawings]

FIG. 1 is a simplified diagram showing an embodiment of a heat pump type hot water supply device of the present invention.

FIG. 2 is a simplified block diagram of a control unit of the heat pump water heater.

FIG. 3 is a flowchart showing an operation control of the heat pump type hot water supply device.

FIG. 4 is an explanatory diagram of a midnight time period and a daytime when the heat pump hot water supply device operates.

FIG. 5 is a flowchart showing an additional boiling operation of the heat pump type hot water supply device.

FIG. 6 is a flowchart showing a reheating operation of the heat pump type hot water supply device.

FIG. 7 is a simplified diagram of a conventional heat pump type hot water supply device.

[Explanation of symbols]

1 tank unit 2 heat pump unit 3 hot water storage tank 25 compressor 28 Evaporator

Claims (5)

[Claims] 1. A heat pump type hot water supply apparatus comprising: a heat pump unit (2); and a tank unit (1) having a hot water storage tank (3) for storing hot water boiled by the heat pump unit (2). A heat pump type hot water supply apparatus characterized by performing operation control for changing the frequency of the compressor (25) of the heat pump unit (2) according to the season so as to boil hot water having a predetermined heat capacity within a time period. 2. The heat pump hot water supply apparatus according to claim 1, wherein operation control is performed to change the fan air volume of the evaporator (28) of the heat pump unit (2) according to the season. 3. The boiling operation during the midnight time and the additional boiling operation during the daytime outside of the midnight time are configured to secure the required amount of hot water, and the boiling operation during the midnight time and the additional boiling operation are performed. The heat pump hot water supply apparatus according to claim 1 or 2, wherein both the operation and the operation are controlled according to the season as described above. 4. The compressor (25) at the time of reheating the shortage when the amount of hot water used exceeds the set required amount.
The heat pump hot water supply apparatus according to claim 3, wherein a frequency increasing operation is performed to increase the frequency of the above-mentioned frequency above the above frequency. 5. The air volume increasing operation for increasing the fan air volume above the fan air volume when replenishing a shortage when the amount of hot water used exceeds the set required hot water volume. Item 4. A heat pump type hot water supply device.