JPH09112976A - Indoor machine of ice heat accumulating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a heat exchanging capability of an indoor device for an ice heat accumulating system in an excellent condition. SOLUTION: During a cooling operation, indoor air is circulated by fans 17 and 18 at outer surfaces of heat transfer coils 11 and 12 arranged side-by-side. At an initial stage of the cooling operation, a first valve 13 is opened and at the same time a second valve 14 is closed, and refrigerant of low temperature lower than 0 deg.C stored in an ice heat accumulating tank 1 is circulated only to the first heat transfer coil 11. As a frost of more than a predetermined amount is adhered to an outer surface of the aforesaid first heat transfer coil 11, this state is detected by a first differential pressure switch P, the first valve 13 is closed and the second valve 14 is opened to cause the refrigerant to be circulated only in the second heat transfer coil 12. Then, as a frost of more than a predetermined amount is adhered to the second heat transfer coil 12, the refrigerant is circulated only to the first heat transfer coil 11 through a second differential pressure switch P. Subsequently, an alternateoperation of the aforesaid two heat transfer coils 11 and 12 is repeated.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an indoor unit used in an ice heat storage system.

[0002]

2. Description of the Related Art Recently, an ice heat storage system has begun to attract attention in order to effectively utilize nighttime power and reduce peak power for cooling during the daytime. The ice heat storage system
The refrigerator is configured to freeze part of the liquid refrigerant in the ice heat storage tank and supply the liquid refrigerant in the tank (or a liquid refrigerant containing ice) to the heat transfer coil of the indoor unit. See, for example, Japanese Examined Patent Publication No. 4-2871).

[0003]

By the way, in order to increase the heat exchange capacity while making the above indoor unit compact, the above-mentioned refrigerant is used indoors at a temperature as low as almost 0 ° C (or 0 ° C or less). It is desirable to supply to the heat transfer coil of the machine. However, in this case, the following problem occurs.

That is, when the above-mentioned low-temperature refrigerant is supplied to the heat transfer coil of the indoor unit, the outer surface of the heat transfer coil is also at about 0 ° C.
Since it is cooled (or 0 ° C. or less), water vapor in the air easily becomes frost and adheres to its outer surface. Since the frost hinders heat transfer, the heat exchange capacity of the indoor unit is significantly reduced. In addition, when using a refrigerant containing ice, because the ice pieces and ice particles are clogged in the tube of the heat transfer coil of the indoor unit, the amount of liquid passing to the heat transfer coil of the same is likely to decrease,
There is an adverse effect that the heat exchange capacity of the indoor unit is further reduced. An object of the present invention is to maintain the heat exchange capacity of an indoor unit for an ice storage system in a good state.

[0005]

In order to achieve the above object, the present invention has an indoor unit for an ice heat storage system configured as follows.

(Invention of Claim 1) The invention of Claim 1 is configured as follows, for example, as shown in any one of FIGS. 1 to 3. Two systems of heat transfer paths 11 and 12 arranged in parallel to which a low-temperature refrigerant of approximately 0 ° C. or 0 ° C. or less is supplied, and a valve device 15 for controlling the refrigerant flow rate of each of the above heat transfer paths 11 and 12.
A blower means 19 for circulating the air to be cooled to the outer surface of each heat transfer path 11.12, and each heat transfer path 11.1 described above.
2 is provided with detection means 21 and 22 for detecting that a predetermined amount or more of frost has adhered to the outer surface, and control means 23 for controlling the valve device 15, and the control means 23 is for the detection means 21. One of the two heat transfer paths 11 and 12 in which frost is detected based on the detection signal of 22.
The valve device 15 is configured to be operable so as to prevent the flow of the low temperature refrigerant to the first heat transfer passage 1 and to allow the flow of the low temperature refrigerant to the other heat transfer path 12 in which no frost is detected. To do.

(Invention of Claim 2) The invention of Claim 2 is configured as follows, for example, as shown in FIG. Two heat transfer paths 11 and 12 arranged in parallel to which a low-temperature refrigerant of approximately 0 ° C. or 0 ° C. or less is supplied, and a valve device 15 that controls the refrigerant flow rate of each of the above heat transfer paths 11 and 12, and the same as above. Each heat transfer path 11 ・
Blower means 19 for circulating the air to be cooled on the outer surface of 12
And a control means 24 for controlling the valve device 15, so that the control means 24 alternately flows the low-temperature refrigerant into the heat transfer paths 11 and 12 according to a preset time. A timer 25 for operating the valve device 15 is provided.

As the low temperature refrigerant in the above claims, brine containing ice chips or ice particles, a slurry mixture of the above ice chips and brine, and the above ice chips are removed. Liquid brine below ℃, ice water of about 0 ℃ containing ice chips, etc.
Cold water can be considered.

[0009]

[Action]

(Invention of Claim 1) The invention of Claim 1 operates as follows, for example, as shown in FIG. During the cooling operation, the air to be cooled is constantly circulated to the outer surface of each of the heat transfer passages 11 and 12 by the blowing means 19. Further, the low temperature refrigerant in the ice heat storage tank 1 can be circulated to the heat transfer paths 11 and 12 described above. In the initial stage of the cooling operation, the valve device 15 allows the flow of the refrigerant to the one heat transfer path 11 and blocks the flow of the refrigerant to the other heat transfer path 12. As a result, the air cooled in one heat transfer path 11 and the air passing through the other heat transfer path 12 are discharged into the room in a mixed state.

When a predetermined amount or more of frost adheres to the outer surface of the one heat transfer path 11 due to the continuation of the cooling operation, one of the detection means 21 detects it and the frost is detected based on the detection signal. The valve device 15 for preventing the flow of the low-temperature refrigerant to the one heat transfer path 11 and the other heat transfer path 12
Allows the flow of low temperature refrigerant to. As a result, the air cooled in the other heat transfer path 12 and the air passing through the one heat transfer path 11 are discharged into the room in a mixed state. Then, the frost adhering to the outer surface of one of the heat transfer paths 11 which is in the above-described pause is quickly melted by the retained heat of the air blown from the blower unit 19.

When a predetermined amount or more of frost adheres to the outer surface of the other heat transfer path 12 in the above by the cooling operation by the other heat transfer path 12, the other detecting means 22 detects it and
Based on the detection signal, the valve device 15 blocks the flow of the low temperature refrigerant to the other heat transfer path 12 and allows the flow of the low temperature refrigerant to the one heat transfer path 11. As a result, the air cooled in the one heat transfer path 11 and the air passing through the other heat transfer path 12 are discharged into the room in a mixed state. Then, the other heat transfer path 1 in the resting state
The frost attached to the outer surface of No. 2 is quickly melted by the retained heat of the air blown from the blower unit 19. During the cooling operation, the alternating operation of the one heat transfer path 11 and the other heat transfer path 12 is repeated.

(Invention of Claim 2) The invention of Claim 2 basically operates in the same manner as the invention of Claim 1 described above, but comparing with the operation of the invention of Claim 1, for example, FIG. As shown in, it differs in the following points. The time required from the start of the cooling operation by the heat transfer paths 11 and 12 until the predetermined amount or more of frost adheres to the heat transfer paths 11 and 12 is the amount of air blown by the air blower 19 and the circulation of the low-temperature refrigerant. Depending on the operating conditions such as quantity
The time required for the above-mentioned frost formation is previously input to the timer 25 of the control means 24.

During operation of one heat transfer path 11, when the operating time of the one heat transfer path 11 exceeds a set time,
The timer 25 blocks the flow of the low temperature refrigerant to the one heat transfer path 11 via the valve device 15 and allows the flow of the low temperature refrigerant to the other heat transfer path 12. This allows
The air cooled in the other heat transfer path 12 and the air passing through the one heat transfer path 11 are discharged into the room in a mixed state. The frost adhering to the outer surface of the one heat transfer path 11 during the above-mentioned suspension is quickly melted by the retained heat of the air blown from the blower unit 19.

When the cooling operation by the other heat transfer path 12 has passed the set time, the flow of the low temperature refrigerant to the other heat transfer path 12 is blocked by the valve device 15 and the heat transfer path 11 is transferred to the other heat transfer path 11. Allow the flow of low temperature refrigerant. As a result, the air cooled in the one heat transfer path 11 and the air passing through the other heat transfer path 12 are discharged into the room in a mixed state. Then, the other heat transfer path 12 in the rest state
The frost adhering to the outer surface of No. 3 is quickly melted by the retained heat of the air blown from the blower unit 19. During the cooling operation, the alternating operation of the one heat transfer path 11 and the other heat transfer path 12 is repeated.

[0015]

【The invention's effect】

(Invention of claim 1) The invention of claim 1 has the following effects.
During the cooling operation of one heat transfer path, the frost adhering to the outer surface of the other heat transfer path can be melted by the heat of the air to be cooled. Since the frost adhering to the outer surface of the heat transfer path can be melted by the retained heat of the air to be cooled, it is possible to prevent the predetermined amount or more of frost from adhering to each heat transfer path. Therefore, it is possible to prevent the heat transfer in the heat transfer path from being hindered by the frost, and it is possible to maintain the heat exchange capacity of the indoor unit in a good state.

When brine or water containing ice chips or ice particles is used as a low-temperature refrigerant, even if the ice chips or ice particles start to become clogged in the heat transfer path, the heat transfer path may be suspended during the rest of the heat transfer path. Since ice pieces and ice particles that have started to be clogged can be melted by the heat of the air to be cooled, the heat transfer passage can be prevented from being blocked inside the pipe and the heat exchange capacity of the indoor unit can be maintained in a good state.

(Invention of Claim 2) The invention of Claim 2 has the following effect in addition to the effect of Claim 1 described above. That is, according to the second aspect of the present invention, since the alternate operation of each heat transfer path is performed according to the set time of the timer, it is not necessary to provide the detection means for frost formation, so that the configuration of the control means is simplified.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 shows a first embodiment and is an overall system diagram of an ice heat storage system. A part of the liquid brine in the storage chamber 2 of the ice heat storage tank 1 is configured to be frozen by a refrigerator (not shown), and the brine in the tank 1 is
The refrigerant can be supplied to the indoor unit 4 provided in the middle of the circulation path 3. Reference numeral 5 is a supply pump.

The indoor unit 4 includes two systems of first heat transfer coil 11 and second heat transfer coil 12 arranged in parallel. Electromagnetic first valves 13 and second valves 14 for controlling the brine flow rates of the heat transfer coils 11 and 12 are provided at the inlets of the heat transfer coils 11 and 12, respectively. A valve device 15 is constituted by these two valves 13 and 14. Further, a first fan 17 and a second fan 18 for circulating the air in the room are provided on the outer surfaces of the heat transfer coils 11 and 12 described above. The two fans 17 and 18 form a blower unit 19.

First and second differential pressure switches P and P are provided in order to detect the pressure difference between the upstream side and the downstream side of the heat transfer coils 11 and 12 in the blowing direction. As frost adheres to the outer surface of the heat transfer coil 11 (or 12), the flow resistance of the air passing through the heat transfer coil 11 (or 12) above increases, so the above-mentioned upstream side and downstream side The pressure difference between and also increases. By detecting that the pressure difference becomes equal to or more than the set value by the differential pressure switch P, it is determined that the predetermined amount or more of frost has adhered to the outer surface of the heat transfer coil 11 (or 12). That is, the frost detection means 21 and 22 by the differential pressure switches P and P described above.
Is configured.

The motor 17a of each of the fans 17 and 18 described above
18a, the valves 13 and 14 described above, and the differential pressure switches P and P described above are connected to the electronic control means 23. The control means 23 operates as follows, for example.

During the cooling operation, the above two fans 17
18 are driving together. Further, in the initial stage of the cooling operation, the first valve 13 is opened and the second valve 14 is opened.
Is closed and the liquid brine in the tank 1 is supplied to the first heat transfer coil 11. As a result, the first fan 1
The air blown by 7 and cooled by the first heat transfer coil 11 and the blown air of the second fan 18 are mixed and discharged into the room (for example, refer to FIG. 5 described later).

By continuing the above cooling operation, the above first
As frost adheres to the outer surface of the heat transfer coil 11, the pressure difference between the upstream side and the downstream side of the first heat transfer coil 11 in the air blowing direction increases. When the first differential pressure switch P detects that the pressure difference becomes equal to or larger than the set value, the first valve 13 is closed and the second valve 14 is opened based on the detection signal. Then, the supply of the brine to the first heat transfer coil 11 is stopped and the brine is supplied to the second heat transfer coil 12, whereby the second fan 1
The air blown by 8 and cooled by the second heat transfer coil 12 and the air blown by the first fan 17 are mixed and discharged into the room. Then, the frost adhering to the outer surface of the first heat transfer coil 11 which is in the rest state is the first fan 1
It is melted early by the retained heat of the air blown from 7.

When a predetermined amount or more of frost adheres to the outer surface of the second heat transfer coil 12 of the same as above by the cooling operation by the second heat transfer coil 12, the above-mentioned is detected based on the detection signal of the second differential pressure switch P. The second valve 14 is closed and the first valve 13 is opened. Then, the supply of the brine to the second heat transfer coil 12 is stopped, and the brine is supplied to the first heat transfer coil 11, so that the first fan 17 blows the brine to the first heat transfer coil. The air cooled by 11 and the air blown by the second fan 18 are mixed and discharged into the room. Then, the second heat transfer coil 1 in the rest state
The frost attached to the outer surface of No. 2 is quickly melted by the retained heat of the air blown from the second fan 18. During the cooling operation, the alternating operation of the first heat transfer coil 11 and the second heat transfer coil 12 described above is repeated.

The first valve 13 and the second valve 14 are
It may be configured by an electric valve whose opening degree can be adjusted. In this case, it is possible to quickly adjust the cooling temperature by controlling the flow rate of the brine supplied to the one heat transfer coil 11 (or 12) during the cooling operation. When circulating brine containing ice such as ice chips or ice particles as the refrigerant, select the appropriate flow rate according to the ice content with the above motorized valve to distribute ice in cold water. It is possible to make the states uniform. As a result, the temperature distribution inside the tube of the heat transfer coil can be made uniform, and the cooling capacity can be improved.

2 to 4 show a second embodiment, a third embodiment and a fourth embodiment, respectively, and the above-mentioned first embodiment.
A part of the embodiment is modified as follows. In the second to fourth embodiments, the first
Elements having the same functions as those in the embodiment will be described with the same reference numerals.

(Second Embodiment) In the second embodiment of FIG. 2, the valve device 15 is composed of one three-way valve. Further, each of the detection means 21 and 22 includes an air temperature sensor T _A that detects the outlet temperature of the cooled air and a refrigerant temperature sensor T _C that detects the outlet temperature of the brine. As the frost adheres to the heat transfer coil 11 (or 12), the temperature difference between the outlet temperature of the air and the outlet temperature of the brine increases. Therefore, it is noted that the temperature difference exceeds the set value. The defrosting of the heat transfer coil 11 (or 12) is started based on the detection by the two temperature sensors T _A and T _C.

(Third Embodiment) In the third embodiment of FIG. 3, the blower means 19 is composed of one fan. Further, each of the detecting means 21 and 22 is composed of a coolant temperature sensor T _C that detects the outlet temperature of the brine. As the frost adheres to the heat transfer coil 11 (or 12), the brine outlet temperature decreases, so that the temperature sensor T indicates that the temperature has become equal to or lower than the set value.
_The defrosting of the heat transfer coil 11 (or 12) is started based on the detection by _C.

(Fourth Embodiment) In the fourth embodiment of FIG. 4, the refrigerant temperature sensor T _C in FIG. 3 (third embodiment) is omitted, and is constructed as follows. It That is, similarly to each of the first to third embodiments, two parallel heat transfer paths 11 and 12 to which a low-temperature refrigerant is supplied are provided, and the refrigerant flow rate of each heat transfer path 11 and 12 is changed. The valve device 15 is configured to be controllable, and an air blower 19 for circulating the air to be cooled is provided on the outer surface of each of the heat transfer passages 11 and 12 above.
Then, the valve device 15 is controlled to be opened / closed in accordance with a preset time by the timer 25 provided in the control means 24, whereby the low temperature refrigerant is alternately flown to the heat transfer passages 11 and 12.

The above embodiments can be modified as follows. The valve device 15 may be provided on the outlet side of the heat transfer coils 11 and 12 above, instead of being provided on the inlet side of the heat transfer coils 11 and 12. In order to increase the cooling capacity, a large amount of brine is supplied to the one heat transfer coil 11 (or 12) while the other heat transfer coil 12 (or 11) is not defrosted. A small amount of brine may be supplied. In this case, in the above-described first embodiment of FIG. 1, third embodiment of FIG. 3, and fourth embodiment of FIG. 4, the first valve 13 and the second valve 14 are configured by motor-operated valves whose opening can be adjusted. It suffices to do so. In the second embodiment of FIG. 2, the valve device 15 composed of a three-way valve may be configured as a variable diversion type.

The blower means 19 is a motor 17a-1.
It is preferable that the amount of air flow can be adjusted by an inverter attached to 7b or the amount of air flow can be adjusted by a damper. In order to defrost the resting heat transfer coil 11 (or 12) by the air to be cooled, a defrost-dedicated fan that supplies relatively warm air such as air staying in the upper space of the room is used. Alternatively, the warm air of the dedicated fan may be mixed with the supply air of the blower unit 19 described above. In this case, the heat transfer coil 11 (or 12)
The frost attached to the can be efficiently melted. Note that the supply of the cooled air by the blower unit 19 may be not only the forced ventilation as shown in each embodiment but also the suction ventilation.

The low temperature refrigerant supplied to the heat transfer coils 11 and 12 may be a brine containing ice instead of the liquid brine. In this case, ice pieces or ice particles in the supplied brine may be clogged in the heat transfer coil 11 (or 12). However, the clogged ice chips and ice particles
While the heat transfer coil 11 (or 12) is at rest, the fan 17
(Or 18) is quickly melted by the retained heat of the air blown from it, so it does not hinder the next operation. In addition,
The low temperature refrigerant may be cold water or ice water at approximately 0 ° C.

The valves 13 and 14 may be fluid pressure operated type instead of electromagnetic type or electric type. Further, in the first embodiment of FIG. 1 and the second embodiment of FIG. 2, the blower unit 19 may be a single fan instead of disposing the two fans 17 and 18. .

Next, an example of arrangement of the heat transfer coils in each of the above embodiments will be described with reference to FIGS. The arrow in each figure has shown the flow of air. In the first arrangement example of FIG. 5, two packages 26 and 27 are arranged in parallel in the vertical direction, and the heat transfer coils 11 and 12 are provided in the respective packages 26 and 27. The air blown from a fan (not shown) passes through the heat transfer coils 11 and 12 and is discharged into the room in a mixed state.

In the second arrangement example of FIG. 6, two packages 2 are provided.
6.27 are arranged in parallel in the horizontal direction, and each package 2
The above-mentioned heat transfer coils 11 and 12 are provided in 6.27.

In the third arrangement example of FIG. 7, two packages 2 are provided.
6 ・ 27 are arranged in series in the horizontal direction, and each package 2
The above-mentioned heat transfer coils 11 and 12 are provided in 6.27. This third arrangement example corresponds to the first arrangement example and the second arrangement example.
Compared to the arrangement example, when the air flow rate is the same, the air flow rate per package is doubled, so that the cooling capacity is improved and the air passing through the two heat transfer coils 11 and 12 can be mixed well.

The fourth arrangement example in FIG. 8 is one package 2
Two heat transfer coils 11 and 12 are arranged in parallel in the up-down direction inside 8. Note that two heat transfer coils may be arranged in parallel or in series in the horizontal direction within one package.

[Brief description of the drawings]

FIG. 1 shows the first embodiment of the present invention and is an overall system diagram of an ice heat storage system.

FIG. 2 shows the second embodiment of the present invention and is a system diagram of an indoor unit for the ice heat storage system.

FIG. 3 shows a third embodiment of the present invention and is a diagram corresponding to FIG. 2 described above.

FIG. 4 shows a fourth embodiment of the present invention and is a view corresponding to FIG. 2 above.

FIG. 5 is a schematic diagram showing a first arrangement example of heat transfer coils in each of the above embodiments.

FIG. 6 is a schematic diagram showing a second arrangement example of the heat transfer coil.

FIG. 7 is a schematic diagram showing a third arrangement example of the heat transfer coils of the same.

FIG. 8 is a schematic diagram showing a fourth arrangement example of the heat transfer coils of the same.

[Explanation of symbols]

11.12 ... Heat transfer path (heat transfer coil), 15 ... Valve device, 19
... blower means, 21/22 ... detection means, 23 ... control means,
24 ... Control means, 25 ... Timer.

Claims (2)

[Claims] 1. A heat transfer path (11) (12) of two systems arranged in parallel, which is supplied with a low temperature refrigerant of approximately 0 ° C. or less, and a refrigerant of each of the heat transfer paths (11) (12). Valve device that controls the flow rate
(15), blower means (19) for circulating the air to be cooled to the outer surface of each heat transfer path (11) (12), and the outer surface of each heat transfer path (11) (12) Detecting means (21) (22) for detecting that a predetermined amount or more of frost is attached, and the valve device (1
5) controlling means (23) for controlling the detecting means (21) (22).
Based on the detection signal of the heat transfer path (11) (1) of the above two systems
Of the 2), the flow of the low temperature refrigerant to the one heat transfer path (11) in which frost is detected is blocked, and the flow of the low temperature refrigerant to the other heat transfer path (12) in which no frost is detected is allowed. An indoor unit for an ice heat storage system, characterized in that the valve device (15) is operated as described above. 2. A heat transfer path (11) (12) of two systems arranged in parallel, which is supplied with a low temperature refrigerant of approximately 0 ° C. or below 0 ° C., and a refrigerant of each of the heat transfer paths (11) (12). Valve device that controls the flow rate
(15), blower means (19) for circulating the air to be cooled to the outer surface of each heat transfer path (11), (12), and the above valve device
A control means (24) for controlling (15), and the control means (24) alternately supplies the low temperature refrigerant to the heat transfer paths (11) and (12) according to a preset time. An indoor unit for an ice heat storage system, comprising a timer (25) for operating the valve device (15) so as to flow.