JP6118065B2 - Water-cooled air conditioning system and operation control method thereof - Google Patents

Description

  The present invention relates to a water-cooled air-conditioning system, and more particularly to a water-cooled air-conditioning system suitable as an air-conditioning system for small and medium-sized buildings.

  Referring to FIG. 6, the conventional water-cooled air conditioning system 100 connects the outgoing water header 101 and the return water header 102 with a bypass pipe 103, and connects the heat source unit 104, the outgoing water header 101, and the returned water header 102 to each other. A chilled water circulation circuit 105 and a secondary chilled water circulation circuit 106 connecting between the outgoing water header 101, each air conditioner 104 and the return water header 102, and the chilled water produced by the heat source device 104 is connected to the secondary chilled water circulation circuit 106 side. To supply. In this case, when the cooling load on the air conditioner 104 side is small, cold water is circulated to the bypass pipe 103 side, and the heat source device 104 is operated under constant outlet temperature control (for example, 7 ° C.).

  In such an air conditioning system, operation at a partial load with a load factor of 50% or less generally occupies about 70% or more of the total operation time. For this reason, in order to prevent a decrease in operating efficiency during this period, in large-scale building air conditioning systems, the control of the number of heat source units for low-load operation, the adoption of heat source units with high partial load efficiency, the variable flow rate of the transport system, heat storage Load leveling by system introduction is performed (for example, Patent Document 1).

JP 2009-63231 A

However, in medium and small-scale air conditioning systems, application of the control of the number of heat source units is limited because the heat load is small. Moreover, since the load leveling involves a significant change in the air conditioning system, it is difficult to adopt. For these reasons, there are cases in which medium and small-scale air conditioning systems have hardly taken measures against a decrease in operating efficiency at low loads.
The present invention is for solving the above-described problems, and provides a water-cooled air conditioning system technology that can avoid a decrease in operating efficiency at low loads without requiring a significant system change.

The gist of the present invention is as follows. That is, the water-cooled air conditioning system according to the present invention is
(1) In the water-cooled air conditioning system that circulates cold water produced by the heat source unit (2a) to one or more air conditioners (4) through the outgoing header (6) and the return water header (2f),
An air conditioner bypass pipe (2g) that bypasses the air conditioner (4) and connects the outgoing water header (6) and the return water header (2f);
An air storage unit (5) having a latent heat storage material filled in the air-conditioner bypass pipe (2g) path;
And comprising
Without using the circuit connecting the heat source machine (2a), the outgoing water header (6), the air conditioner (4), and the return water header (2f), the air conditioner can be used without supplying cold water to the heat storage and heat dissipation device (5) side. (4) normal operation mode supplied to the side,
Using a circuit connecting the heat source machine (2a), the outgoing water header (6), the heat storage and heat dissipation device (5), and the return water header (2f), at least a part of the cold water is circulated and supplied to the heat storage and heat dissipation device (5) side. Thermal storage operation mode to
Using the circuit connecting the incoming water header (6), the air conditioner (4), the return water header (2f), and the heat storage and heat dissipation device (5), the cold energy stored in the heat storage and heat dissipation device (5) during the heat storage operation mode is obtained. , A heat dissipation operation mode for circulating supply to the air conditioner (4),
Is configured so that operation can be switched as appropriate.

(2) In the above invention, further comprising a heat storage and heat dissipation device bypass pipe (31) that bypasses the heat storage and heat dissipation device,
And in the said thermal radiation operation mode, it comprised so that the return water which returns to a return water header could be mixed with the cold water from the said heat storage and heat dissipation apparatus, It was characterized by the above-mentioned.

In addition, the operation control method of the water-cooled air conditioning system according to the present invention includes:
(3) The water-cooled air conditioning system is characterized in that a return water ratio between cold water and return water from the heat storage and heat dissipation device is controlled in accordance with a cooling load on the air conditioner side.

According to the present invention, there is an effect that it is possible to avoid a decrease in operation efficiency at the time of a low cooling load by adding a simple facility without a significant system change.
Furthermore, since no major system changes are required, it is easy to adopt air conditioning systems for medium and small-sized buildings, which account for about 90% of existing buildings, and can meet Japan's demand for energy conservation promotion.

It is a figure showing the whole water-cooling type air-conditioning system 1 composition concerning a first embodiment. It is a figure which shows the detailed structure of the thermal storage / dissipation apparatus. It is a figure which shows the cold water circulation channel in the normal operation mode of the water cooling type air conditioning system. It is a figure which shows the cold water circulation channel in the heat storage operation mode of the water cooling type air conditioning system. It is a figure which shows the cold water circulation flow path in the thermal radiation operation mode of the water cooling type air conditioning system. It is a figure which shows the whole structure of the water cooling type air conditioning system 30 which concerns on 2nd embodiment. It is a figure which shows the cold water circulation flow path in the heat storage operation mode of the water cooling type air conditioning system. It is a figure which shows the cold water circulation flow path in the thermal radiation operation mode of the water cooling type air conditioning system. It is a figure which shows the whole structure of the water cooling type air conditioning system 40 which concerns on 3rd embodiment. It is a figure which shows the cold water circulation flow path in the heat storage operation mode of the water cooling type air conditioning system. It is a figure which shows the cold water circulation flow path in the thermal radiation operation mode of the water cooling type air conditioning system. It is a figure which shows the whole structure of the water cooling type air conditioning system 50 which concerns on 4th embodiment. It is a figure which shows the cold water circulation flow path in the heat storage operation mode of the water cooling type air conditioning system. It is a figure which shows the cold water circulation flow path in the thermal radiation operation mode of the water cooling type air conditioning system. It is a figure which shows the whole structure of the water cooling type air conditioning system 60 which concerns on 5th embodiment. It is a figure which shows the cold water circulation flow path in the heat storage operation mode of the water cooling type air conditioning system. It is a figure which shows the cold water circulation flow path in the thermal radiation operation mode of the water cooling type air conditioning system. It is a figure which shows the structure of the conventional water cooling type air conditioning system.

  Hereinafter, an embodiment of an air-conditioning system according to the present invention will be described in more detail with reference to FIGS. 1 (a) to 5 (c). In the drawings, the same components are denoted by the same reference numerals, and redundant description is omitted. Needless to say, the scope of the present invention is described in the claims and is not limited to the following embodiments.

<First embodiment>
Referring to FIG. 1A, an air conditioning system 1 includes a primary side chilled water circulation system 2 and a secondary side chilled water circulation system 3.
The primary side cold water circulation system 2 is interposed in a heat source machine 2a that is a cold water generation source, a heat source machine outlet pipe 2c that supplies cold water produced by the heat source machine 2a to the outgoing header unit 6, and a pipe 2c path. A two-way valve 2h, a heat source unit inlet pipe 2d for returning the return water from the return water header 2f to the heat source unit 2a, and a bypass pipe 2g directly connecting the two headers. The outgoing header unit 6 includes a primary outgoing header 2e, a secondary outgoing header 3e, and a secondary circulation pump 3g. A heat storage and heat dissipation device 5 is interposed in the bypass pipe 2g path. Moreover, the primary side circulation pump 2b is interposed in the heat source unit inlet pipe 2d path. Although detailed illustration is omitted, the air conditioner 4 is an AHU (Air Handling Unit) or FCU (Fan Coil Unit) equipped with a heat exchanger and a blower, and exchanges heat between cold water and room air to bring the cold air into the air-conditioned room. It can be supplied.
In addition, you may arrange | position the primary side circulation pump 2b in the downstream of the heat-source equipment 2a, and the heat-source equipment exit piping 2c side.

  With reference to FIG.1 (b), the thermal storage / radiation apparatus 5 is equipped with the structure by which the small spherical latent heat storage material 5a was filled inside the outer side container 5b and the heat insulation layer 5c. As the latent heat storage material 5a, a paraffin-based latent heat storage material or the like can be used.

The secondary-side chilled water circulation system 3 includes an incoming water header unit 6, an outgoing water pipe 3a, a branch pipe 3c, a return water pipe 3b, and an air conditioner 4 interposed in the route of the branch pipe 3c, And a valve 3d as a main component. Although not shown in detail, the secondary chilled water circulation system 3 includes a plurality of secondary chilled water circulation systems 3 ′.
A differential pressure sensor S1 capable of measuring a differential pressure (Pr) between the headers is installed between the outgoing header 2e and the return header 2f, and the secondary circulation pump 3g is controlled so that Pr becomes a constant value. It is configured as follows.
In addition, assuming a case where the required amount of water on the secondary side is lower than the lower limit amount of water of the first circulating pump 3g, there may be a pipe that bypasses between the primary side outgoing water header 2e and the secondary side outgoing water header 3e. is there.

  The water-cooled air conditioning system 1 is configured as described above. Next, referring to FIGS. 1C to 1E, a control flow for supplying cold water to the air conditioner in the present embodiment will be described sequentially. . In the following flow, each step is performed at a predetermined time interval in consideration of stabilization of control. Further, the control command of the present embodiment is executed by a control unit (not shown). In the following flow, the operating states of the two-way valve 2h and the circulation pump 2b under each operating condition are as shown in Table 1.

  At the start of the control, the heat source unit 2a is operated under a constant outlet temperature control (for example, 7 ° C.). It is assumed that the primary circulation pump 2b is in an operating state and the two-way valve 2h is in an open state. Further, the secondary circulation pump 3g performs control so as to maintain the inter-header differential pressure (Pr) at a constant value. The cold water circulation in this state is as shown by the thick line in FIG.

  Thereafter, for example, due to a decrease in cooling demand of the air conditioner 4, the amount of circulating water by the secondary side circulation pump 3 g decreases due to the opening degree of the control valve 3 d becoming small or fully closed. On the other hand, since the amount of water circulated by the primary side circulation pump 2b does not change, the difference in the amount of water is supplied to the bypass pipe 2g side, and the corresponding cold energy is stored in the heat storage and heat dissipation device 5 installed in the bypass pipe 2g path. It will be. The cold water circulation in this state is as shown by a thick line in FIG.

  From this state, if the inter-header differential pressure (Pr) is lower than the preset minimum value (P_min), it is determined that the cooling load on the air conditioner side is further smaller, and the heat source device 2a and the primary side circulation pump 2b is stopped and the two-way valve 2h is closed. Accordingly, the cold water circulation is as shown in FIG. 1E, and the air conditioner 4 is cooled by the heat radiation from the heat storage and heat dissipation device 5.

Thereafter, when the inter-header differential pressure (Pr) exceeds the minimum value (P_min), the two-way valve 2i is opened, and the operation of the heat source unit 2a and the primary side circulation pump 2b is restarted.
In the present embodiment, an example in which switching from the heat source machine operation to the heat radiation operation of the heat storage and heat dissipation device 5 is controlled by the differential pressure (Pr) between the headers is shown. It can also be set as the aspect determined by the heat storage state (for example, internal temperature) of the latent heat storage material in the heat radiator 5.

  In addition, even when the heat source device 2a and the primary circulation pump 2b are stopped due to failure or maintenance inspection, the two-way valve 2h is closed in the same manner as described above, thereby releasing heat stored in the heat storage and heat dissipation device 5. The air conditioner 4 can be cooled.

<Second Embodiment>
Further, another embodiment of the present invention will be described. The present embodiment relates to a mode in which a primary circulation pump is used during heat radiation by the heat storage and heat dissipation device 5 and the water supply temperature is adjusted by mixing the return water according to the load during heat radiation to increase the heat radiation operation. .

Referring to FIG. 2A, the configuration of the water-cooled air conditioning system 30 according to the present embodiment is different from the above-described water-cooled air-conditioning system 1 in that the primary-side circulation pump 36 is installed on the heat source unit outlet piping 2c side. It has been done. In addition, a circulation pump bypass pipe 37 that connects the heat source unit outlet pipe 2c and the bypass pipe 2g is provided. Further, a heat storage / radiation device bypass pipe 31 that bypasses the heat storage / heat dissipation device 5 and connects the return water header 2 f and the bypass pipe 37 is provided. Furthermore, two-way valves 32, 33, 35 and a three-way valve 34 are interposed in the piping path connecting the heat source device 2a and the outgoing water header 2e. In addition, the bypass two-way valve 2h interposed in the piping 2c path | route of the water cooling type air conditioning system 1 is not provided.
The other configuration is the same as that of the water-cooled air conditioning system 1, and thus a duplicate description is omitted.

Next, the aspect of the cold water circulation in the heat storage operation mode and the heat radiation operation mode of the water-cooled air conditioning system 30 will be described. In addition, since the cold water circulation flow path in the normal operation mode is the same as that in each of the above-described embodiments, a duplicate description is omitted.
Table 2 shows the operation control of the control valve and the circulation pump under each operation condition.

上表において、放熱運転モードの三方弁３４は、温度センサＳ３１の温度が設定値となるように、配管３１側、３７側の開度を制御する（※１）。
上表の弁制御により、蓄熱運転モード、放熱運転モードにおける冷水循環はそれぞれ図２（ｂ）、図２（ｃ）の循環流路となり、水冷式空調システム１と同様の通常運転、蓄熱運転、放熱運転が行われる。

In the above table, the three-way valve 34 in the heat radiation operation mode controls the opening degree on the pipe 31 side and the 37 side so that the temperature of the temperature sensor S31 becomes a set value (* 1).
Due to the valve control in the above table, the chilled water circulation in the heat storage operation mode and the heat radiation operation mode becomes the circulation flow path of FIG. 2 (b) and FIG. 2 (c), respectively. A heat dissipation operation is performed.

<Third embodiment>
Further, another embodiment of the present invention will be described. The present embodiment relates to a mode in which a secondary circulation pump is used for the heat radiation operation mode and the return water is mixed according to the load at the time of heat radiation to extend the heat radiation operation, particularly in an emergency such as a heat source machine failure. This is an aspect that enables air conditioning to be secured.

  Referring to FIG. 3A, the configuration of the water-cooled air conditioning system 40 according to this embodiment is different from that of the above-described water-cooled air-conditioning system 1 in that the return heat header 2f and the incoming water are bypassed by bypassing the heat storage and heat dissipation device 5. This is that a return water bypass pipe 43 connecting the header 2e is provided. A three-way valve 41 is interposed at the junction of the return water bypass pipe 43 and the bypass pipe 2g. Further, a temperature sensor S41 is disposed in the vicinity of the outlet of the incoming water header 2e. The other configuration is the same as that of the water-cooled air conditioning system 1, and thus a duplicate description is omitted.

  Next, the aspect of the cold water circulation in the normal operation mode, the heat storage operation mode, and the heat radiation operation mode of the water-cooled air conditioning system 40 will be described. Table 3 shows the operation control of the control valve and the circulation pump under each operating condition.

（※２）放熱運転モードの三方弁４１は、温度センサＳ４１の温度が設定値となるように、配管２ｇ側、４３側の開度を制御する。

(* 2) The three-way valve 41 in the heat radiation operation mode controls the opening degree of the piping 2g side and the 43 side so that the temperature of the temperature sensor S41 becomes a set value.

  By the valve control shown in the above table, the chilled water circulation in the heat storage operation mode and the heat radiation operation mode becomes the circulation flow paths of FIGS. 3B and 3C, respectively. In the heat radiation operation mode, cold water (eg, 7 ° C.) discharged from the heat storage / heat dissipation device 5 and recirculated cold water (eg, 12 ° C.) through the return water bypass pipe 43 are mixed within a range that does not hinder the operation of the air conditioner 4, Since the cooling capacity is reduced because the air is supplied to the air conditioner 4, the heat radiation operation mode time can be extended.

<Fourth embodiment>
Further, another embodiment of the present invention will be described. The present embodiment relates to a mode in which the cold water circulation of the entire system is performed only by the circulation pump 2b.

Referring to FIG. 4A, the configuration of the water-cooled air conditioning system 50 according to the present embodiment is different from that of the water-cooled air-conditioning system 1 in that the incoming water header 57 in the secondary-side cold water circulation system 3 The water header, the secondary circulation pump, and the piping 3f are not provided.
A pipe 51 connecting the bypass pipe 2g and the heat source unit inlet pipe 2d and a pipe 52 bypassing the heat source unit 2a are provided. Furthermore, the bypass pipe 2g is provided with a two-way valve 53, the pipe 51 is provided with a two-way valve 54, and the pipe 52 is provided with a two-way valve 55. The other configuration is the same as that of the water-cooled air conditioning system 1, and thus a duplicate description is omitted.

Next, the aspect of the cold water circulation in the heat storage operation mode and the heat radiation operation mode of the water-cooled air conditioning system 50 will be described.
Table 4 shows the operation control of the control valve and the circulation pump under each operation condition.

  Due to the valve control in the above table, the chilled water circulation in the heat storage operation mode and the heat radiation operation mode becomes the circulation flow path of FIG. 4 (b) and FIG. 4 (c), respectively. A heat dissipation operation is performed.

<Fifth embodiment>
Further, another embodiment of the present invention will be described. The present embodiment relates to a mode in which the heat radiation operation is extended for a long time by appropriately mixing the return water with the outgoing water according to the cooling load in the heat radiation operation mode.

With reference to FIG. 5A, the configuration of the water-cooled air conditioning system 60 according to the present embodiment is different from the water-cooled air-conditioning 50 described above in that a bypass pipe 61 that connects the heat source unit inlet pipe 2d and the pipe 51 is provided. The three-way valve 62 is installed at the junction of both pipes.
The other configuration is the same as that of the water-cooled air conditioning system 60, and therefore redundant description is omitted.

  Next, the aspect of the cold water circulation in each operation mode of the water cooling type air conditioning system 60 will be described. Table 5 shows the operation control of the control valve and the circulation pump under each operating condition.

（※３）放熱運転モードにおいて、三方弁６２は温度センサＳ７１の温度が設定値となるように、配管２ｇ側、５７側の開度を制御する。
上表の弁制御により、蓄熱運転モード、放熱運転モードにおける冷水循環はそれぞれ図５（ｂ）、図５（ｃ）の循環流路となり、水冷式空調システム１と同様の通常運転、蓄熱運転、放熱運転が行われる。

(* 3) In the heat radiation operation mode, the three-way valve 62 controls the opening degree on the pipe 2g side and the 57 side so that the temperature of the temperature sensor S71 becomes a set value.
By the valve control in the above table, the chilled water circulation in the heat storage operation mode and the heat radiation operation mode becomes the circulation flow path of FIG. 5 (b) and FIG. 5 (c), respectively. A heat dissipation operation is performed.

  The present invention is widely applicable to water-cooled air conditioning systems regardless of the type of heat source, refrigerant, building structure, and the like.

1, 30, 40, 50, 60 ··· Water-cooled air conditioning system 2 ··· Primary side cold water circulation system 2a · Heat source device 2b · Primary side circulation pump 2e and 57 · · · Outflow header 2f ... Return water header 2g ... Air conditioning bypass piping 3 ... Secondary side cold water circulation system 4 ... Air conditioner 5 ... Heat storage / dissipation device 6 ... Outbound header unit 2h , 32, 33, 35, 42, 53-56, 63-65... Two-way valve 34, 41, 62... Three-way valve S1,.・ Temperature sensor

Claims (3)

In the water-cooled air conditioning system that circulates cold water produced by the heat source device (2a) to one or more air conditioners (4) through the outgoing header (6) and the return water header (2f),
An air conditioner bypass pipe (2g) that bypasses the air conditioner (4) and connects the outgoing water header (6) and the return water header (2f);
An air storage unit (5) having a latent heat storage material filled in the air-conditioner bypass pipe (2g) path;
And comprising
Without using the circuit connecting the heat source machine (2a), the outgoing water header (6), the air conditioner (4), and the return water header (2f), the air conditioner can be used without supplying cold water to the heat storage and heat dissipation device (5) side. (4) normal operation mode supplied to the side,
When the cooling demand on the air conditioner side decreases, at least one of the cold water is used by using a circuit connecting the heat source unit (2a), the forward water header (6), the heat storage / radiation device (5), and the return water header (2f). A heat storage operation mode in which a part is circulated and supplied to the heat storage and dissipation device (5) side,
When the cooling demand on the air conditioner side further declines, a heat storage operation mode is established using a circuit connecting between the incoming water header (6), the air conditioner (4), the return water header (2f), and the heat storage and heat dissipation device (5). A heat radiation operation mode in which the cold energy stored in the heat storage and heat dissipation device (5) is circulated and supplied to the air conditioner (4);
A water-cooled air conditioning system characterized in that the operation can be appropriately switched. The heat storage and heat dissipation device bypass pipe (31) that bypasses the heat storage and heat dissipation device is further provided,
The water-cooled air conditioning system according to claim 1, wherein in the heat radiation operation mode, the return water returning to the return water header can be mixed with the cold water discharged from the heat storage and heat dissipation device. The water-cooled air conditioning system according to claim 1 or 2 ,
A water-cooled air conditioner that improves operation efficiency at low cooling loads by appropriately switching the normal operation mode, the heat storage operation mode, or the heat dissipation operation mode in accordance with the cooling load on the air conditioner side. System operation control method.

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