JP4388637B2 - Air conditioner - Google Patents

Description

[0001]
[Field of the Invention]
The present invention relates to an air conditioner in which a sensible heat cooler is installed inside a building, an external air conditioner is installed outside the air-conditioned room, and cold water is used as a heat medium.
[0002]
[Prior art]
FIG. 4 shows an example of a conventional air conditioner that uses cold water as a heat medium. An air-conditioned room a1, an air circulation path a2, a fan filter unit a3, and a sensible heat cooler b are installed in a building a. An external air conditioner c is installed outside, and sensible heat generated indoors is cooled by the sensible heat cooler b. In addition to the air cooler d, the external air conditioner c is provided with a heating coil c1, a steam humidifier c2, and a blower c3, and controls the temperature and humidity of the air supplied to the air-conditioned room a1. Cold water supplied from a refrigerator not shown is supplied to the sensible heat cooler b and the air cooler d through the control valves b1 and d1 of the parallel passages e11 and e12 from the cold water main pipe e1 and becomes high temperature. Water is discharged from the return main pipe e2.
[0003]
In such an air conditioner in which the humidity control to the air-conditioned room a1 is assigned to the external controller c and the temperature control is assigned to the sensible heat cooler b provided in the indoor circulation system, the required air conditioning operation is performed. In order to achieve this, it is necessary to control the amount of cold water passing through the cooler with high accuracy.However, if the temperature difference between the inlet and outlet of the cold water is large, the accuracy of the air conditioning temperature and humidity will decrease. When the humidity in the air-conditioning room is under dew point control, the temperature difference between the inlet and outlet of the chilled water in the air cooler must be kept at a small temperature difference of about 5 ° C to prevent condensation in the sensible heat cooler b. I must. However, in order to air-condition a large amount of air while maintaining the cold water at a small temperature difference, it is necessary to circulate a large amount of cold water, and the cooler and the water pump must have a large capacity. Equipment costs and power costs are high.
[0004]
[Problems to be solved by the invention]
It is an object of the present invention to allow an external air conditioner to perform a highly accurate air conditioning operation while performing large temperature difference water supply with a large temperature difference between the inlet and outlet of cold water and to reduce the load on the refrigerator.
[0005]
[Means for Solving the Problems]
Means for solving the above-mentioned problems are as described in each claim, and among them, the means of claim 1 sends circulating air to an air-conditioned room having a facility that generates a substantially constant cooling load throughout the year. An air circulation path is provided, a sensible heat cooler is installed in the air circulation path, an external air conditioner that air-conditions the outside air and sends it to the air-conditioned room is installed outside the room, and is covered by the sensible heat cooler and the external air conditioner. In the air conditioner that air-conditions the air conditioning room, a pre-heat exchanger is placed upstream of the air conditioner as viewed from the flow of air to be processed through the air conditioner, and an air cooler is placed downstream. Is sent in parallel to the sensible heat cooler and the air cooler, and the heat medium discharged from the air cooler is supplied to the front heat exchanger. In winter, the heat medium is sent to the sensible heat cooler, A feature is that the heat medium exiting the cooler is supplied to the pre-heat exchanger.
[0006]
According to this means, the sensible heat cooler of the air-conditioned room, the pre-heat exchanger of the external air conditioner, and the air cooler can be combined according to the outside air condition. Although the difference heat medium is supplied, the temperature difference of the heat medium is distributed to the pre-heat exchanger and the air cooler to cool, so even if a large temperature difference heat medium is used, the temperature difference per heat exchanger Thus, high cooling efficiency and high cooling accuracy are maintained. In winter, the pre-heat exchanger is heated with a high-temperature heat medium that has exited the sensible heat cooler, so no special piping is required .
[0007]
According to a second aspect of the present invention, there is provided an external control system comprising a circulation system cold water pipe for feeding water to a sensible heat cooler installed in an air circulation path leading to an air-conditioned room, and an air cooler and a front heat exchanger connected in series. The outdoor air chilled water pipes that supply water to the machine are arranged in parallel, the summer air valve is provided in the outdoor air chilled water pipes, and the sensible heat cooler and the pre-heat exchanger are connected by high temperature cold water pipes to separate the high temperature cold water pipes. The summer cooling valve is connected to the return main pipe, and the connection pipe of the air cooler and the pre-heat exchanger is connected to the return main pipe via the summer closing valve and the medium temperature cold water pipe. Open the valve and close the summer closing valve, cooling the sensible heat cooler circuit and the externally connected air cooler and the front heat exchanger connected in series in parallel. The summer valve is closed and the summer valve is opened. The sensible heat cooler and the pre-heat exchanger are operated in series, and the sensible heat cooler cools and the outside heat is heated by the pre-heat exchanger. To.
[0008]
According to this means, the passage of the cooling water is switched by operating the summer opening valve and the summer closing valve, and the facility that generates a substantially constant cooling load throughout the year is cooled by the sensible heat cooler, and in summer The outside air sent to the air-conditioned room is cooled by the air conditioner, and the outside air sent to the air-conditioned room in winter is preheated by the pre-heat exchanger in the air conditioner and returns to the return medium. Cooling.
[0009]
Furthermore, the means of claim 3 includes a sensible heat cooler installed in an air circulation path leading to the air-conditioned room, an external air conditioner for adjusting the temperature of the outside air to the air-conditioned room, and supplying the sensible heat cooling And a common heat medium main pipe for sending cold water to the external air conditioner and a common return main pipe for receiving return water from the sensible heat cooler and the external air conditioner. In the air conditioner in which the air cooler is introduced and arranged in order from the outside air, the heat medium main pipe is branched so that the heat medium can be sent in parallel to the sensible heat cooler and the air cooler, Branch the heat medium exiting the sensible heat cooler one side back to the main pipe, the other to the front heat exchanger, the outlet of the front heat exchanger is connected to the return main pipe, and The outlet of the air cooler is joined in the middle of the conduit between the outlet of the pre-heat exchanger and the return main pipe, and the outlet and return of the sensible heat exchanger And during the main pipe, to the between the inlet of the heating medium main air cooler, between main return air cooler, characterized in that a respective on-off valve. This means is a concrete means for carrying out the inventions of claims 1 and 2.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a building, which is provided with an air-conditioned room 2 having a ventilation floor 2 a and an air circulation path 4 having a fan filter unit 3 for filtering and circulating air. A sensible heat cooler 5 is installed. The air-conditioned room 2 is a clean room, and many production apparatuses (not shown) are provided.
[0011]
An outside air conditioner, that is, an outside air conditioner 6 is installed outside the building 1, and an air cooler 7 and a front heat exchanger 8 are connected to the inside of the building 1 through a connecting pipe 11. A heater 10 including a heating coil and an electric heater is installed, and an air supply pipe 9 a for sending air conditioned by the external air conditioner 6 to the air-conditioned room 2 by the blower 9 communicates with the building 1. A humidifier (not shown) is provided on the downstream side of the heater 10.
[0012]
The chilled water main pipe 12 is for supplying a 7 ° C. heat medium cooled by a refrigerator (not shown), that is, chilled water. The chilled water main pipe 12 is branched into a circulatory system chilled water pipe 13 and an outdoor air chilled water pipe 14. The sensible heat cooler 5 provided in the air circulation path 4 is connected. The outdoor air system cold water pipe 14 supplies cold water as a heat medium to the external air conditioner 6, and is connected to the air cooler 7, and is connected to the downstream side of the air cooler 7 via the connection pipe 11. An exchange 8 is connected. A summer opening valve 15 is provided in the middle of the outdoor air system cold water pipe 14 when the outside air temperature is high, such as in summer, and closed when the outside air temperature is low, such as in winter. The outlet side of the sensible heat cooler 5 is connected to a high-temperature cold water pipe 16 for flowing high-temperature cold water that has absorbed heat generated in the air-conditioned room 2, and the high-temperature cold water pipe 16 is connected to the front heat exchanger 8. And is connected to a return main pipe 18 via another summer opening valve 17.
[0013]
The connecting pipe 11 is connected to the return main pipe 18 via a summer closing valve 19 and an intermediate temperature cold water pipe 20 which are closed when the temperature is high such as summer and open when the temperature is low such as winter. In the figure, reference numerals 5a, 7a, 8a are flow rate adjusting bypass passages, and the flow rate of the heat medium passing through the sensible heat cooler 5 and the air cooler 7 is controlled by a three-way valve. In addition to the three-way valve, control valves 5b and 7b are also provided.
[0014]
FIG. 2 shows an operating state at a high temperature such as summer, the summer closing valve 19 is closed, and the intermediate temperature cold water pipe 20 is disconnected. The 7 ° C. cold water flowing into the sensible heat cooler 5 from the cold water main pipe 12 through the circulation system cold water pipe 13 cools the sensible heat cooler 5 to become high temperature cold water of 17 ° C., and the high temperature cold water is converted into the high temperature cold water pipe 16. To return to the main pipe 18. The 7 ° C. cold water flowing in through the outdoor air system cold water pipe 14 and the summer opening valve 15 flows through a circuit in which the air cooler 7, the connecting pipe 11 and the pre-heat exchanger 8 are connected in series to become 17 ° C. high temperature cold water. It flows into the cold water pipe 16, merges with the high temperature cold water exiting the sensible heat cooler 5, and flows out from the return main pipe 18 through the summer opening valve 17. In some cases, a booster pump may be interposed in the series circuit.
[0015]
Since the chilled water flowing through the sensible heat cooler 5 and the external air conditioner 6 has an inlet temperature of 7 ° C. and an outlet temperature of 17 ° C., a large temperature difference water supply of 10 ° C. is performed. The amount of water supply is smaller than that for small temperature difference water supply, and the water pump, the sensible heat cooler 5, the air cooler 7, and the front heat exchanger 8 need only have a small capacity.
[0016]
As described above, since the large temperature difference water supply with a difference of 10 ° C. is performed also for the external conditioner 6, the inlet temperature of the air cooler 7 is set to 7 ° C., the outlet temperature is set to 12 ° C., and the inlet of the front heat exchanger 8 is set. The temperature can be set to 12 ° C. and the outlet temperature to 17 ° C. With this setting, the air cooler 7 and the front heat exchanger 8 change in temperature by 5 ° C., so the change in the water temperature per cooler is small and the fluctuation range of the temperature of the cooled air is kept small. The temperature can be controlled with high accuracy. Further, since the pre-heat exchanger 8 is provided in addition to the air cooler 7, the load on the air cooler 7 can be reduced, and the pre-cooling heat of the heat medium that has passed through the air cooler 7 can be reduced by the pre-heat exchanger 8. It can be used and cold energy is used effectively. Furthermore, since the large temperature difference water supply is performed, the apparatus is downsized and the power for conveying the heat medium is reduced.
[0017]
FIG. 3 shows the operating state at a low temperature such as winter, and the summer opening valves 15 and 17 are closed, the summer closing valve 19 is opened, the outside air chilled water pipe 14 is disconnected from the air cooler 7, and the summer opening is started. The downstream side of the valve 17 and the return main pipe 18 are not connected. That is, the branch from the cold water main pipe 12 to the air cooler 7 and the merge from the high temperature cold water pipe 16 to the return main pipe 18 are not functioned. Accordingly, the cold water flows from the circulation system cold water pipe 13 to the sensible heat cooler 5 to cool the air-conditioned room 2 to become high-temperature cold water at 17 ° C., and the high-temperature cold water flows through the high-temperature cold water pipe 16 and is preheated. The low-temperature outside air that enters the exchanger 8 and is sucked into the external air conditioner 6 is heated by the pre-heat exchanger 8 to lower the water temperature, becomes medium-temperature cold water at 12 ° C., and returns from the medium-temperature cold water pipe 20 to the main pipe 18. Returned.
[0018]
By this operation in winter, the high-temperature cold water of 17 ° C. exiting the sensible heat cooler 5 preheats the outside air entering the external air conditioner 6 with the pre-heat exchanger 8 , thereby reducing the amount of heat source used in the heating coil 10. Alternatively, the equipment of the heating coil 10 can be reduced in size, and the cold water temperature can be reduced to 12 ° C., whereby the load on the refrigerator as a cold heat source can be reduced. Furthermore, when the heating load of the heating coil 10 is small, the phenomenon that the water and steam in the heating coil 10 are frozen due to a low flow rate is dissipated from the pre-heat exchanger 8 for the heat acquired from the air-conditioned room 2. Can be avoided.
[0019]
The summer opening valve 19 shown in the figure is a two-way valve that opens and closes the intermediate temperature cold water pipe 20, but instead, the connection pipe 11 is switched to the outlet pipe 7b of the air cooler 7 and the intermediate temperature cold water pipe 20 side. It can be provided as a way valve.
[0020]
【The invention's effect】
As described above, according to the means of claim 1, an air cooler and a pre-heat exchanger are provided in series in the external air conditioner, and in the summer, cooling water is supplied to the serial cooler and the heat exchanger. Since the temperature change of the cooling water is shared, a large temperature difference water supply that requires a small amount of water can be carried out, and the air cooler, the pre-heat exchanger, the water pump, etc. can be made small and of small power. Further, since the amount of change in the water temperature per cooler is small, the fluctuation range of the air temperature is small, and there is an effect that highly accurate control can be performed. In winter, the high-temperature chilled water generated by cooling the cooling load that exists even in winter is used for heating the outside air that is sucked into the external air conditioner and is cooled by the outside air, so that the heating load and the load on the refrigerator can be reduced. There is.
[0021]
Further, according to the means of claim 2 or claim 3, the same effect as described in claim 1 can be obtained by a simple operation of switching the cooling water passage between the summer open valve and the summer close valve or the open / close valve according to the season. There is an advantage that can be played.
[Brief description of the drawings]
FIG. 1 is an arrangement diagram of each element showing an embodiment of the present invention. FIG. 2 is an explanatory diagram of an action in summer. FIG. 3 is an explanatory diagram of an action in winter.
2 Air-conditioned room 4 Air circulation path 5 Sensible heat cooler 6 External conditioner 7 Air cooler 8 Pre-heat exchanger 11 Connection pipe 12 Chilled water main pipe 13 Circulation chilled water pipe 14 Outside air chilled water pipe 15, 17 Summer opening valve 16 High temperature cold water pipe 18 Return main pipe 19 Summer closing valve 20 Medium temperature cold water pipe

Claims (3)

  An air circulation path that sends circulating air to an air-conditioned room that has facilities that generate a substantially constant cooling load throughout the year is installed, and a sensible heat cooler is installed in the air circulation path to conditioned the outside air and send it to the air-conditioned room. In an air conditioner that installs an air conditioner to be aired outside and air-conditions the air-conditioned room with a sensible heat cooler and an external air conditioner, on the upstream side of the air conditioner as viewed from the flow of air to be processed passing through the air conditioner A pre-heat exchanger and an air cooler are arranged downstream. In summer, the heat medium is sent in parallel to the sensible heat cooler and the air cooler, and the heat medium from the air cooler is pre-heat exchanged. An air conditioner configured to supply a heat medium to a sensible heat cooler and supply the heat medium discharged from the sensible heat cooler to a pre-heat exchanger in winter.   A chilled water pipe that feeds water to the sensible heat cooler installed in the air circulation path leading to the air-conditioned room, and an outdoor air chilled water pipe that feeds water to the external air conditioner that is connected in series with the air cooler and the pre-heat exchanger Are arranged in parallel, the summer air valve is provided in the outside air system cold water pipe, the sensible heat cooler and the pre-heat exchanger are connected by a high temperature cold water pipe, and the high temperature cold water pipe is returned through another summer valve opening. Connect to the main pipe, connect the connection pipe of the air cooler and the pre-heat exchanger to the return main pipe via the summer closing valve and the medium temperature cold water pipe, and in summer, open the two summer opening valves and close the summer closing valve In parallel, the sensible heat cooler circuit and the externally connected air cooler and front heat exchanger connected in series are cooled in parallel. In winter, the two summer valves are closed and the summer valve is closed. The air conditioner is characterized in that the sensible heat cooler and the front heat exchanger are operated in series, cooled by the sensible heat cooler, and heated by the front heat exchanger. A sensible heat cooler installed in the air circulation path leading to the air-conditioned room, an external air conditioner that regulates the temperature of the outside air to be supplied to the air-conditioned room, and cold water to the sensible heat cooler and the external air conditioner And a common return main pipe that receives the return of the return water from the sensible heat cooler and the external conditioner. A pre-heat exchanger and an air cooler are installed in the external conditioner from the outside air. In the air conditioners arranged in order, the heat medium main pipe is branched so that the heat medium can be sent in parallel to the sensible heat cooler and the air cooler, and the heat from the sensible heat cooler Branch the medium conduit back to the main pipe and the other to the front heat exchanger, and connect the outlet of the front heat exchanger to the return main pipe and the outlet of the air cooler to the front. The middle of the conduit between the outlet of the stationary heat exchanger and the return main pipe, and the heat medium main pipe between the outlet of the sensible heat exchanger and the return main pipe And between the inlet of the air cooler, between main return air cooler, air conditioner, characterized in that a respective on-off valve.

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