JP2933031B2 - Heat pump system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat pump system comprising a hot water storage tank and a refrigerant circuit.

[0002]

2. Description of the Related Art In a heat pump system as described above, cooling, heating or hot water can be performed by operating a refrigerant circuit having an indoor heat exchanger, an outdoor heat exchanger, a water heat exchanger and the like. I have. Furthermore, in the summer, etc., cold water is stored in a hot water storage tank at night using inexpensive late-night power, and this is used as a cold heat source during the daytime so that cooling operation with reduced power consumption can be performed. (For example, Japanese Patent Application No. 7-30806)
No. 4). Therefore, the peak cut time period during which the power demand becomes maximum in one day (generally PM 1: 00 to PM 4: 00)
In addition, there is a social advantage that power demand is suppressed and stable power supply is assisted, and also there is an advantage that cost-effective cooling for users can be achieved.

[0003]

However, the cooling operation rate in the peak cut time zone often differs depending on the use of the heat pump system. For example, homes often go out during the peak cut time period, and therefore, the cooling operation rate in the peak cut time period is not higher in a home heat pump system than in a commercial heat pump system. This is a general trend. Therefore, in such a heat pump system, even if the cost of the cooling operation during the peak cut time period using the cold storage water is individually inexpensive, it is possible to store unnecessary cold water by consuming late-night power when looking through the season. It is not uncommon for users to be able to enjoy the expected cost benefits.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and an object of the present invention is to prevent unnecessary cold water from being stored at night and reduce running costs by efficient cold storage operation. It is an object of the present invention to provide a heat pump system capable of reducing the heat.

[0005]

Therefore, the heat pump system according to the first aspect comprises a hot water storage tank 1 and an indoor heat exchanger 56.
a to 56c and a water heat exchanger 4;
A heat exchange path 5 is provided so as to be able to exchange heat with the water heat exchanger 4 and circulates hot water in the hot water storage tank 1 to control the temperature thereof. In a heat pump system configured to enable a cold storage operation for storing cold water and a cooling / cooling operation in which the cold heat of the cold water stored in the cooling operation is further cooled in the heat exchange path 5 during the cooling operation, the immediately preceding peak cut is performed. Only when the cooling operation is performed in the time zone, the cool storage operation is permitted in the subsequent midnight power time zone.

[0006] Here, the "peak cut time zone" refers to a time zone in which power demand is maximized in one day as described above, and is generally from PM 1: 00 to PM 4: 00.

[0007] The term "midnight power time zone" refers to a time zone in which cheap midnight power is supplied.

[0008] Further, the "cooling operation" herein includes a cooling / cooling operation, which is the same throughout the present specification.

In the heat pump system according to the first aspect of the present invention, it is necessary to determine whether or not it is necessary to store cold water during the midnight power time period by determining whether or not the cooling operation has been performed during the immediately preceding peak cut time period. Only when it is determined that the cold storage operation is permitted. Therefore, unnecessary cold water can be prevented from being stored at night, and the running cost can be reduced by an efficient cold storage operation.

The heat pump system according to claim 2 is
Only when the cooling operation is performed for a predetermined time or more in the immediately preceding peak cut time period, the cool storage operation is permitted in the subsequent midnight power time period.

In the heat pump system according to the third aspect, only when the cooling operation is performed in the peak cut time period for a predetermined number of consecutive days until the immediately preceding peak cut time period, the cool storage operation is permitted in the subsequent midnight power time period. It is characterized by doing so.

In the heat pump system according to the fourth aspect, only when the cooling operation is performed for a predetermined time or more continuously for a predetermined number of days in the peak cut time until the immediately preceding peak cut time, the cool storage operation is performed in the subsequent midnight power time. Is allowed.

[0013] In the heat pump system according to the second, third or fourth aspect, the running cost can be further reduced by a more efficient cold storage operation.

[0014]

Next, specific embodiments of the heat pump system of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a circuit diagram showing a water system in the heat pump system. In FIG. 1, reference numeral 1 denotes a hot water storage tank, and reference numeral 4 denotes a double-pipe water heat exchanger functioning as a condenser or an evaporator of a refrigerant circuit to be described later. A heat exchange path 5 is provided so as to be able to exchange heat with the water heat exchanger 4, and hot water flows from its inlet side 5b to its outlet side 5a by the operation of a circulation pump 15 interposed therebetween. I have. The outlet side 5a of the heat exchange path 5 is connected to the hot water pipe 17 and the cold water pipe 1 through the first three-way valve 11.
8 and the tapping pipe 17 is connected to the tapping port 6 provided in the middle part of the hot water storage tank 1, while the tapping port 6 is connected to the tapping pipe 6.
The water outlet pipe 18 is connected to the water outlet 8 provided in the hot water storage tank 1 at a lower position than that. On the other hand, the inlet side 5 b of the heat exchange path 5 branches into a hot water intake pipe 19 and a water intake pipe 20 via the second three-way valve 12. The hot water storage tank 1 is located at an intermediate position between the tap 6 and the tap 8.
The hot water intake pipe 9 is connected to the hot water intake port 9 provided on the hot water storage tank 1, while the water intake pipe 20 is connected to the water intake port 7 provided at the lower end of the hot water storage tank 1. In the same figure, reference numeral 22 denotes a water supply pipe for supplying city water to the hot water storage tank 1 while applying water supply pressure, and the hot water storage tank 1 side is connected to the first water supply pipe 24 and the second water supply pipe 25 via the third three-way valve 13. And the first water supply pipe 2 is provided at a first water supply port 2 provided at a lower end of the hot water storage tank 1.
4 is connected, and a second water supply port 10 provided in the hot water storage tank 1 at an intermediate position between the hot water inlet 9 and the water outlet 8.
Is connected to the second water supply pipe 25. Further, a hot water supply port 3 is provided at an upper end portion of the hot water storage tank 1 and a hot water supply pipe 23 is provided.
A drain pipe 21 for draining hot water stored in the hot water storage tank 1 is provided at the lower end. The above-mentioned water system circuit is controlled by the control means 14. The control means 14 is configured using a microcomputer having a CPU, a memory, an input / output interface, and the like. At the outlet side 5a of the heat exchange path 5, the temperature Tm of the water returned from the heat exchange path 5 to the hot water storage tank 1 is set.
A water temperature sensor 5a for detecting the temperature Ts of the city water stored in the hot water storage tank 1 is provided near the second water supply port 10 while the water temperature sensor 5c for detecting the temperature Ts is provided. The water temperature Tm and the city water temperature Ts detected by the respective sensors 5c and 25a are determined by the control unit 14 described above.
To be entered. In FIG.
Is an outside air temperature sensor, and the outside air temperature To detected here is
Are also input to the control means 14.

FIG. 3 is a circuit diagram showing a refrigerant system of a heat pump system having the water heat exchanger 4. The refrigerant system includes a compressor 51 and a four-way switching valve 5 as shown in FIG.
2. An outdoor heat exchanger 53 having an outdoor fan 54, an expansion valve 60, and indoor heat exchangers 56a to 56c each having an indoor expansion valve 68a to 68c and connected in parallel with each other.
Are sequentially connected by lines 69a to 69f.
The liquid shut-off valve 62 and the liquid receiver 55 are interposed in a pipe 69d toward zero, and a gas shut-off valve 63 is interposed in a pipe 69e. Also, a first solenoid valve 58 is interposed in a discharge line 69a of the compressor 51, and a first line 70a in which a second solenoid valve 59 and a first shutoff valve 65 are interposed is branched from the first solenoid valve 58. The other end of the water heat exchanger 4 is connected to one end of the water heat exchanger 4, and the other end of the water heat exchanger 4 and the liquid receiver 55 are connected to a second conduit 70b through a second closing valve 64 and a first capillary tube 67.
Connected with. And the compressor 5 is more than the first closing valve 65.
The first pipe 70a on the first side is connected to a suction pipe 69f of the compressor 51 by a third pipe 70c provided with a third solenoid valve 61, and provided on the liquid receiver 55 and the suction pipe 69f. The accumulator 57 is connected to the accumulator 57 by a fourth conduit 70d including the second capillary tube 66.

Next, the operation of the heat pump system having the above configuration will be described. First, when a cool storage operation command is issued from a control device (not shown) of the entire heat pump system, the control means 14 performs the following control on the refrigerant system circuit. That is, the four-way switching valve 52 shown in FIG. 3 is switched to the passage side shown by a solid line to open the first solenoid valve 58, the third solenoid valve 61 and the expansion valve 60, while the second solenoid valve 59 and each indoor expansion valve are opened. The valves 68a to 68c are closed. Then, the refrigerant discharged from the compressor 51 is circulated as indicated by the dashed arrow shown in the figure, so that the outdoor heat exchanger 53 functions as a condenser and the water heat exchanger 4 functions as an evaporator. On the other hand, for the water system circuit, the first three-way valve 11 shown in FIG.
The circulating pump 15 is operated by switching the three-way valve 13 to the broken line side and the second three-way valve 12 to the solid line side.
Then, the stored water inside flows out from the water intake port 7 provided at the lower end of the hot water storage tank 1, and flows through the heat exchange path 5 via the water intake pipe 20. At this time, the water is cooled by the water heat exchanger 4 functioning as an evaporator, becomes cold water, and is returned from the water outlet 8 to the hot water storage tank 1 again through the water discharge pipe 18. By continuing such an operation, the cold water is stored at the lower end side of the hot water storage tank 1 near the water outlet 8.

Next, the case of performing the cooling operation will be described. The control means 14 performs control for performing cooling operation in response to a cooling operation command from a control device (not shown) of the entire hot water supply apparatus. For the refrigerant system circuit, the four-way switching shown in FIG. The valve 52 is switched to the passage side indicated by a solid line, and the first solenoid valve 58, the expansion valve 60, and each of the indoor expansion valves 68a to 68c
, The second solenoid valve 59 and the third solenoid valve 61 are closed, and the refrigerant discharged from the compressor 51 is circulated as indicated by the solid line in FIG. Then, the indoor heat exchangers 56a to 56c function as evaporators, and the outdoor heat exchanger 53 functions as a condenser.

Further, in the cooling operation, a case will be described in which the cooling / cooling operation is performed by using the cold water stored in the cooling operation. The control means 14 performs control for performing the cooling / cooling operation in response to a cooling / cooling operation command from a control device (not shown) of the entire heat pump system. Four-way switching valve 5 shown in
2, the first solenoid valve 58, the third solenoid valve 61 and the expansion valve 60 are closed, while the second solenoid valve 59 and each of the indoor expansion valves 68a to 68c are opened. The refrigerant discharged from the compressor 51 is circulated as indicated by a dashed line in FIG. Then, the indoor heat exchangers 56a to 56c are made to function as evaporators, and the water heat exchanger 4 is made to function as a condenser without operating the outdoor heat exchanger 53. on the other hand,
For the water system circuit, the second three-way valve 12 shown in FIG. 2 is switched to the solid line side, and the third three-way valve 13 is switched to the broken line side.
The first three-way valve 11 is provided with the above-mentioned city water temperature sensor 2.
The city water temperature Ts detected at 5a and the water temperature sensor 5c
Is controlled on the basis of the return water temperature Tm detected in step (1). That is, the water temperature Tm is compared with the city water temperature Ts, and if the water temperature Tm is equal to or lower than the city water temperature Ts, the first three-way valve 11 is switched to the broken line side, while the water temperature Tm is higher than the city water temperature Ts. At that time, the first three-way valve 11 is switched to the solid line side. With the above control, each of the three-way valves 11, 12, 1
3 and the circulating pump 15 is operated, the cold water stored in response to the cold storage operation command flows out of the water intake port 7 provided at the lower end of the hot water storage tank 1, and this flows through the water exchange pipe 20 through the heat exchange path. Distribute 5 Then, the cold water is allowed to cool down to the water heat exchanger 4 functioning as a condenser, and is returned to the hot water storage tank 1 again. At this time, the temperature of the cold water rises by absorbing heat in the heat exchange path 5, but when the temperature is still lower than that of the city water, the cold water returns to the lower end side near the water outlet 8 while When the temperature is already higher than the city water, the water is returned to the upper end side from the vicinity of the tap 6. Therefore, it is possible to prevent the temperature of the stored cold water from being raised by hot water having a temperature higher than that of city water, and to perform a cooling operation with high efficiency.

In the heat pump system configured as described above, the operation of the control means 14 when a cold storage operation command is issued from the overall control device will be described with reference to the flowchart of FIG. When the entire control device knows from the timer that it has entered the midnight power time zone,
A cold storage operation command is issued to the control means 14. When receiving the cold storage operation command in step S1, the control means 14
Next, in step S2, it is determined whether or not the summer mode button of the remote controller (not shown) is turned on. This summer mode button can be turned on / off by the user
This is for setting whether or not to use the heat pump system in the summer mode. When the heat pump system is used in the summer mode, for example, control to prohibit energization of a midnight power heater (not shown) is performed. On the other hand, when the user does not use the summer mode, it is considered that the cooling operation is not frequently performed. Therefore, when it is determined in step S2 that the summer mode button is OFF, the process proceeds to step S7, and the cold storage operation is performed. Not performed.

If the summer mode button is ON, the process proceeds to step S3, and the history of the cooling operation during the peak cut time period is examined. That is, the control means 14 stores the time at which the cooling operation was performed retroactively in the memory device, and performs the cooling operation continuously for one hour or more in the peak cut time period of PM 1:00 to 4:00. It is determined whether or not the operation has been performed in both the immediately preceding peak cut time period and the previous day's peak cut time period.
When it is determined that the cooling operation has been performed, the process proceeds to step S4. However, when it is determined that such a cooling operation has not been performed, it is considered that there is a low possibility that the cooling operation will be performed on the next day, so the process proceeds to step S7. The cold storage operation is not performed.

By the way, the control means 14 controls the PM of the day.
The outside air temperature To at 1:00 is read from the outside air temperature sensor 16 and stored in the memory device.
Therefore, in step S4, it is determined whether or not the outside air temperature To at PM 1:00 is 30 ° C. or higher.
When the temperature is not 30 ° C. or more, even if the cooling operation has the above history, it is determined that the possibility of performing the cooling operation during the peak cut time period on the next day is low, and the process proceeds to step S7 to perform the cold storage operation. Not performed.

On the other hand, the outside air temperature To at 1:00 PM
Is equal to or higher than 30 ° C., the process proceeds to step S5. In step S5, the cool storage start permission time (for example, AM
At 3:00), the water temperature Ts in the hot water storage tank 1 is read from the city water temperature sensor 25a. This water temperature Ts is 30 ° C.
If not, the cold storage operation is started in step S6,
If the temperature is not equal to or lower than 30 ° C., considerable power consumption can be considered for the cold storage operation itself. Therefore, the process proceeds to step S7 and the cold storage operation is not performed. In step S6, the time when the cold storage operation is started is determined using the outside air temperature To and the water temperature Ts instead of immediately starting the cold storage operation.

In the above heat pump system,
Even if it becomes late-night power time zone, it does not start cold storage operation unconditionally, but only when cooling operation for more than 1 hour is performed in the peak cut time zone for two days until the last peak cut time zone Then, the cool storage operation is permitted during the following midnight power hours. Therefore, the cold storage operation is performed only when there is a high possibility that the cooling operation will be performed again during the immediately following peak cut time period, and it is possible to avoid storing unnecessary cold water and reduce the running cost of the cooling operation. it can. Further, since the outside air temperature To and the water temperature Ts are also used as judgment data when permitting the cold storage operation, the running cost of the cooling operation can be further reduced.

Although the specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be implemented with various modifications within the scope of the present invention. For example, the water system circuit shown in FIG. 2 and the refrigerant system circuit shown in FIG. 3 of the heat pump system are examples, and are limited to those shown in the figure if the same cooling operation, cooling / cooling operation, and cold storage operation are possible. Not in translation. Although the operation of the control means 14 has been described using the flowchart of FIG. 1, the duration and the number of days of the cooling operation in the peak cut time period, or the outside air temperature To and the water temperature Ts in the hot water storage tank 1 at PM 1:00 are as follows. The determination may be made by comparing with a reference different from the reference shown in FIG. Although the above heat pump system is configured using a single hot water storage tank 1, the present invention is also applied to a heat pump system configured using a plurality of hot water storage tanks to reduce the running cost of cooling operation. Can be.

[0026]

According to the heat pump system of the first aspect of the present invention, it is determined whether or not it is necessary to store cold water during the midnight power time period by determining whether or not the cooling operation has been performed during the immediately preceding peak cut time period. The cold storage operation is permitted only when it is determined that. Therefore, unnecessary cold water can be prevented from being stored at night, and the running cost can be reduced by an efficient cold storage operation.

In the heat pump system according to the second, third or fourth aspect, the running cost can be further reduced by the more efficient cold storage operation.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an operation of a control unit of a heat pump system according to an embodiment of the present invention.

FIG. 2 is a water circuit diagram of the heat pump system.

FIG. 3 is a refrigerant circuit diagram of the heat pump system.

[Explanation of symbols]

 1 Hot Water Storage Tank 4 Water Heat Exchanger 5 Heat Exchange Path 56a Indoor Heat Exchanger 56b Indoor Heat Exchanger 56c Indoor Heat Exchanger

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Atsushi Matsubara 1000 Oya, Okamotocho, Kusatsu-shi, Shiga 2 Daikin Industries, Ltd. Shiga Works (56) References JP-A-1-244228 (JP, A) JP-A-1-244227 (JP, A) JP-A-6-235557 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F24F 11/02

Claims (4)

(57) [Claims] A hot water storage tank (1) and an indoor heat exchanger (5)
6a-56c) and a water heat exchanger (4), and a refrigerant circuit provided so as to be able to exchange heat with the water heat exchanger (4) and circulating hot water in the hot water storage tank (1). A heat exchange path (5) for controlling the temperature of the hot water, cooling operation, cold storage operation for storing cold water in the hot water storage tank (1) by midnight power, and cold water stored during the cooling operation. In the heat pump system configured to be able to perform the cooling / cooling operation in which the cooling heat is allowed to cool down in the heat exchange path (5), the cooling operation is performed in the immediately preceding peak cut time period, and the cooling operation is performed in the subsequent midnight power time period. A heat pump system wherein cold storage operation is permitted. 2. The heat pump system according to claim 1, wherein the cool storage operation is permitted in a subsequent midnight power time zone only when the cooling operation is performed for a predetermined time or more in the immediately preceding peak cut time zone. . 3. The cooling operation is permitted in the subsequent midnight power time zone only when the cooling operation is performed in the peak cut time zone for a predetermined number of consecutive days until the immediately preceding peak cut time zone. The heat pump system according to claim 1, wherein 4. The cool storage operation is permitted in a subsequent midnight power time zone only when a cooling operation for a predetermined time or more has been performed for a predetermined time continuously for a predetermined number of days until the immediately preceding peak cut time zone. 2. The method according to claim 1, wherein
Heat pump system.