JP2007155263A - Factory air conditioning equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a refrigerating machine from uselessly operating due to heat generated in a circulation pump. <P>SOLUTION: An automatic control panel 80 determines whether or not a detected temperature of a water temperature sensor 70 is 10°C or higher in Step S100, and determines whether or not the opening of a cold water valve 60 is 60% or more in Step S110. When the thermal load in the factory is increased, the temperature of a water refrigerant is increased, and the opening of the cold water valve 60 is increased. Then the detected temperature of the water temperature sensor 70 becomes 10°C or higher (Step S110: YES), the opening of the cold water valve 60 becomes 60% or more (Step S110: YES), and the first refrigerating machine 10 is started (Step S120). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a factory air conditioner for cooling a factory.

  2. Description of the Related Art Conventionally, in factories that handle volatile substances, it is required to set a large number of ventilations in order to avoid volatilization of volatile substances in the factory and increase the concentration of volatile substances in the air.

  Corresponding to such a factory, a refrigerator that cools the water refrigerant, an indoor unit that introduces outside air, cools the introduced outside air with the water refrigerant cooled by the refrigerator, and blows it into the factory, and an electric motor There is a factory air conditioner equipped with a circulation pump that circulates water refrigerant between the refrigerator and the indoor unit by operating the electric motor.

  In this, a water temperature sensor that detects the temperature of the water refrigerant discharged from the indoor unit, and when the detected temperature of the water temperature sensor exceeds a threshold value, the refrigerator is started, and when the detected temperature of the water temperature sensor falls below the threshold value And a control device for stopping the refrigerator.

  In the factory air conditioner described above, the outside air temperature decreases at night in the intermediate period such as spring and autumn, so the amount of heat entering the factory is reduced. For this reason, since the heat load in the factory is smaller than in the summer, the amount of heat transferred from the outside air to the water refrigerant in the indoor unit is reduced. Therefore, the temperature of the water refrigerant discharged from the indoor unit may be lower than the above threshold value.

  Here, since the circulation pump generates heat from the electric motor as it operates, the water refrigerant discharged from the indoor unit is warmed by the heat from the electric motor despite the small heat load in the factory. If the water temperature exceeds the above threshold, the refrigerator may start. However, since the amount of heat generated from the circulation pump is small, after the refrigerator is started, the operation is stopped in a short period, and then the operation is repeated again for a short period of time. For this reason, the problem that a refrigerator consumes electric power wastefully arises.

  An object of this invention is to provide the factory air conditioner which suppressed that a freezer operate | moves wastefully with the heat which generate | occur | produces from a circulation pump in view of the said point.

  To achieve the above object, an indoor unit (50) including a first refrigerator (10), a blower (51), and a cooling heat exchanger (52), a circulation pump (40), and the cooling A water temperature detecting means (70) for detecting the temperature of the water refrigerant discharged from the heat exchanger, and detecting the heat load in the factory, and when the detected heat load is less than the first level, and the water temperature When the detected temperature of the detecting means is lower than the first cold water temperature, the first refrigerator is stopped at any one of the temperatures, and the detected heat load is equal to or higher than the first level and the water temperature is detected. And a control device (80) for starting the first refrigerator when the temperature detected by the means is equal to or higher than the first cold water temperature.

  Therefore, although the heat load in the factory is low, it is possible to suppress the operation of the first refrigerator by the heat generated from the circulation pump.

  In addition, the code | symbol in the bracket | parenthesis of each means described in a claim and this column shows the correspondence with the specific means as described in embodiment mentioned later.

  FIG. 1 shows an embodiment of a factory air conditioner according to the present invention. FIG. 1 shows a schematic configuration of a factory air conditioner. The factory air conditioner of this embodiment includes first and second refrigerators 10 and 20, water pipes 30, 31, 32, 33, a circulation pump 40, an indoor unit 50, a cold water valve 60, a water temperature sensor 70, and a room temperature sensor. 71, power switches 72a and 72b, a temperature setter 72c, an outside air temperature sensor 73, and an automatic control panel 80.

  The first and second refrigerators 10 and 20 are well-known refrigerators that cool the water refrigerant by the refrigeration cycle apparatus, respectively. The first and second refrigerators 10 and 20 are refrigerants in the water pipe 30. It is connected in parallel to the flow (see arrow Y in the figure).

  The water pipe 30 is provided for flowing the water refrigerant discharged from the first and second refrigerators 10 and 20 to the indoor unit 50. The water pipe 31 is provided to return the water refrigerant discharged from the indoor unit 50 to the first and second refrigerators 10 and 20.

  The circulation pump 40 is disposed in an intermediate portion of the water pipe 30 and has an electric motor. The operation of the electric motor causes the first and second refrigerators 10 and 20 and the indoor unit 50 to be connected. Circulate the water refrigerant.

  The indoor unit 50 includes an electric blower 51 and a heat exchanger 52 for cooling. The electric blower 51 introduces outside air and blows it out into the factory. The cooling heat exchanger 52 is connected to the water pipes 30 and 31 via the water pipes 32 and 33, and the outside air introduced by the electric blower 51 is supplied by the water refrigerant flowing from the water pipe 32. Cooling.

  The cold water valve 60 is an electromagnetic valve that is connected between the water pipes 30 and 32 and adjusts the flow rate flowing into the cooling heat exchanger 52. The room temperature sensor 71 detects the air temperature in the factory. The water temperature sensor 70 detects the temperature of the water refrigerant discharged from the cooling heat exchanger 52. The outside air temperature sensor 73 detects the temperature of outside air outside the factory.

The power switch 72a is a switch for supplying power from the commercial power source to the first and second refrigerators 10 and 20 and the circulation pump 40 and stopping the power. The power switch 72b is a switch that supplies power from the commercial power source to the electric blower 51 and stops it.
The temperature setter 72c is a switch for setting a target temperature of the air temperature in the factory. The automatic control panel 80 includes each sequence control circuit that controls the first and second refrigerators 10 and 20 and the chilled water valve 60 in parallel.

  Next, a specific operation of the factory air conditioner according to the present embodiment will be described with reference to FIGS. 2, 3, and 4.

  When the operator turns on the power switch 72a, power is supplied from the commercial power source to the first and second refrigerators 10, 20 and the circulation pump 40. Accordingly, since the circulation pump 40 is activated, the circulation pump 40 circulates the water refrigerant between the first and second refrigerators 10 and 20 and the indoor unit 50. Here, when the automatic control panel 80 determines that the power switch 72a is turned on based on the output signal from the power switch 72a, the first and second refrigerators according to the flowcharts of FIGS. Controls 10 and 20 are started.

  Next, when the operator turns on the power switch 72b, power is supplied from the commercial power source to the electric blower 51. Along with this, the electric blower 51 is activated, and the electric blower 51 introduces outside air into the factory.

  At this time, when the automatic control panel 80 determines that the power switch 72b is turned on based on the output signal from the power switch 72b, the control panel 80 starts controlling the chilled water valve 60 according to the flowchart of FIG. Hereinafter, the control of the first refrigerator 10, the control of the second refrigerator 20, and the opening degree control of the cold water valve 60 will be described individually.

(Control of first refrigerator 10)
Control of the first refrigerator 10 by the automatic control panel 80 will be described with reference to FIG.
First, it is determined in step S100 whether or not the detected temperature of the water temperature sensor 70 is 10 ° C. or higher. When the detected temperature of the water temperature sensor 70 is lower than 10 ° C. (step S100: NO), the determination process of step S100 is performed again, and when the detected temperature of the water temperature sensor 70 is 10 ° C. or higher (step S100: YES), step The process proceeds to S110.

  Here, it is determined in step S110 whether or not the opening degree of the cold water valve 60 is 60% or more. As will be described later, the opening degree of the cold water valve 60 is controlled in accordance with the heat load in the factory. And when the opening degree of the cold water valve 60 is less than 60% (step S110: NO), it returns to step S100. As described above, when the temperature detected by the water temperature sensor 70 is less than 10 ° C. and when the opening degree of the cold water valve is less than 60%, the first refrigerator 10 has The stop state is maintained.

  Thereafter, when the outside air temperature rises and the heat load in the factory increases, the opening degree of the chilled water valve 60 is widened as the heat load increases, and the indoor unit 50 is used for cooling as the outside air temperature rises. Since the amount of heat transferred from the outside air to the water refrigerant in the heat exchanger 52 increases, the temperature of the water refrigerant rises.

  At this time, when the detected temperature of the water temperature sensor 70 is 10 ° C. or higher (step S100: YES) and the opening degree of the cold water valve 60 is 60% or higher (step S110: YES), the first refrigerator 10 is started. (Step S120). Accordingly, the first refrigerator 10 cools the water refrigerant, and the cooled refrigerant is supplied to the cooling heat exchanger 52 by the operation of the circulation pump 40.

  Thereafter, as long as the detected temperature of the water temperature sensor 70 is 8 ° C. or higher (step S130: NO) and the opening degree of the cold water valve 60 is maintained at 50% or higher (step S140: NO), the first refrigerator 10 is operated. Continue state.

  Next, when the outside air temperature decreases, the amount of heat transferred from the outside air to the water refrigerant in the cooling heat exchanger 52 decreases. Accordingly, when the temperature detected by the water temperature sensor 70 is less than 8 ° C., YES is determined in step S130 and the first refrigerator 10 is stopped (step S150). Even when NO is determined in step S130, when the heat load in the factory decreases and the opening degree of the cold water valve 60 is less than 50% (step S140: YES), the first refrigerator 10 is stopped ( Step S150).

  Then, it returns to step S100 and repeats the control process of above-mentioned step S100-S150. Accordingly, the first refrigerator 10 is controlled based on the heat load in the factory and the temperature of the water refrigerant, and is started and stopped.

(Control of second refrigerator 20)
The automatic control panel 80 activates the second refrigerator 20 to assist the first refrigerator 10 when the outside air temperature is high such as in summer and the heat load in the factory is high. Hereinafter, control of the second refrigerator 20 by the automatic control panel 80 will be described with reference to FIG.

  First, the detected temperature of the water temperature sensor 70 is 12 ° C. or higher (step 200: YES), the opening degree of the cold water valve 60 is 60% or higher (step S210: YES), and the detected temperature of the outside air temperature sensor 73 is 25 ° C. or higher. (Step S220: YES), the second refrigerator 20 is started. Accordingly, the second refrigerator 20 cools the water refrigerant, and the cooled refrigerant is supplied to the cooling heat exchanger 52 by the operation of the circulation pump 40.

  Thereafter, the detected temperature of the water temperature sensor 70 is 10 ° C. or higher (step S240: NO), the opening degree of the cold water valve 60 is 50% or higher (step S250: NO), and the detected temperature of the outside air temperature sensor 73 is 20 ° C. or higher. If it is (step S260: NO), the operating state of the second refrigerator 20 is maintained.

  Thereafter, when the heat load in the factory is reduced and the temperature detected by the water temperature sensor 70 is less than 10 ° C., YES is determined in step S240, and the second refrigerator 20 is stopped (step S270). Even when NO is determined in step S240, if the opening degree of the cold water valve 60 is 50% or less, YES is determined in step S250, and the second refrigerator 20 is stopped (step S270). Furthermore, even when it is determined as NO in step S250, when the outside air temperature is lowered and the temperature detected by the outside air temperature sensor 73 is 20 ° C. or less, it is determined as YES in step S260 and the second refrigerator 20 is stopped ( Step S270).

  Then, it returns to step S200 and repeats the control process of above-mentioned step S200-S260. Thus, the second refrigerator 20 is controlled based on the heat load in the factory, the temperature of the water refrigerant, and the outside air temperature, and is started and stopped. Then, the water refrigerant cooled by the second refrigerator 20 is supplied to the cooling heat exchanger 52 by the operation of the circulation pump 40.

(Control of cold water valve 60)
Control of the cold water valve 60 by the automatic control panel 80 will be described with reference to FIG.
First, a temperature difference ΔT (= target temperature−detected air temperature) between a target temperature in the factory and a detected air temperature of the room temperature sensor 71 is obtained as a heat load in the factory (step S300). Accordingly, the opening degree of the cold water valve 60 is adjusted based on the temperature difference ΔT (step S310).

  Specifically, as shown in the characteristic diagram G in FIG. 4, the temperature difference ΔT (that is, the heat load in the factory) and the opening degree of the chilled water valve 60 are determined in advance so as to be specified on a one-to-one basis. As the temperature difference ΔT increases, the opening degree of the chilled water valve 60 is gradually increased. For this reason, as the temperature difference ΔT increases, the amount of water refrigerant flowing into the cooling heat exchanger 52 increases, and the cooling capacity of the cooling heat exchanger 52 increases. In the graph G in FIG. 4, temperature differences ΔT1 and ΔT2 corresponding to 60% and 50% of the opening degree of the cold water valve 60 correspond to the first level described in the claims.

By repeating the control processing of steps S300 and S310 as described above,
The cooling capacity of the cooling heat exchanger 52 is adjusted in accordance with the temperature difference ΔT, and the outside air introduced by the electric blower 51 is cooled by the adjusted cooling heat exchanger 52 and blown out into the factory.

  According to the present embodiment described above, the automatic control panel 80 uses the temperature of the water refrigerant and the heat load in the factory (specifically, the opening degree of the cold water valve 60) to provide the first and second refrigerators 10. , 20 are controlled. For this reason, although the heat load in the factory is small, it is possible to prevent the refrigerator from operating wastefully due to the heat generated by the circulation pump 40.

  In the above-described embodiment, the example in which the first and second refrigerators 10 and 20 are controlled using the opening degree of the cold water valve 60 as the heat load in the factory has been described. The first and second refrigerators 10 and 20 may be controlled using the temperature difference ΔT between the temperature and the detection value of the room temperature sensor 71.

  In the above-described embodiment, the example in which the factory air conditioner is configured by using the two refrigerators 10 and 20 has been described. However, the present invention is not limited thereto, and the factory air conditioner is configured by using only one refrigerator. Also good.

  In the above-described embodiment, an example in which the outside air temperature is used when controlling the refrigerator 20 has been described. However, the refrigerator 20 may be controlled using only the air temperature in the factory and the temperature of the water refrigerant.

  In the above-described embodiment, the example of calculating the temperature difference ΔT between the target temperature in the factory and the actual air temperature in the factory as the heat load in the factory has been described. The heat load in the factory may be calculated by taking humidity, amount of solar radiation, etc. into account for the temperature difference ΔT.

  In the above-described embodiment, the example in which the outside air temperature is 25 ° C. and 20 ° C. is described as the first outside air temperature. However, the present invention is not limited to this, and other values other than the outside air temperature 25 ° C. and 20 ° C. may be used. .

  In the above-described embodiment, an example in which 10 ° C. and 8 ° C. are used as the first cold water temperature has been described. However, the present invention is not limited to this, and other values other than 10 ° C. and 8 ° C. may be used.

In the above-described embodiment, an example in which 12 ° C. and 10 ° C. are used as the second cold water temperature has been described. However, the present invention is not limited to this, and other values other than 12 ° C. and 10 ° C. may be used.
In the above-described embodiment, the example of using 60% and 50% as the opening degree of the cold water valve 60 used when controlling the first and second refrigerators 10 and 20 has been described. Other values may be used.

It is a mimetic diagram showing one embodiment of the factory air conditioner concerning the present invention. It is a flowchart which shows a control process in order to control the 1st refrigerator of FIG. It is a flowchart which shows a control process in order to control the 1st refrigerator of FIG. It is a flowchart which shows a control process in order to control the cold water valve of FIG.

Explanation of symbols

10, 20 ... Refrigerator, 40 ... Circulation pump, 50 ... Indoor unit,
60 ... Cold water valve, 70 ... Water temperature sensor, 71 ... Room temperature sensor,
72a, 72b ... power switch, 72c ... temperature setting device, 73 ... outside air temperature sensor, 80 ... automatic control panel.

Claims (3)

A first refrigerator (10) for cooling the water refrigerant;
A blower (51) that introduces outside air and blows it out into the factory, and a cooling heat exchanger (52) that cools the outside air introduced by the blower with water refrigerant cooled by the first refrigerator. Indoor unit (50),
A circulation pump (40) having an electric motor and circulating the water refrigerant between the first refrigerator and the heat exchanger by the operation of the electric motor;
Water temperature detecting means (70) for detecting the temperature of the water refrigerant discharged from the cooling heat exchanger;
The thermal load in the factory is detected, and when the detected thermal load is lower than the first level and when the detected temperature of the water temperature detecting means is lower than the first cold water temperature, Sometimes the first refrigerator is stopped, and the first refrigeration is performed when the detected heat load is not less than a first level and the detected temperature of the water temperature detecting means is not less than a first cold water temperature. A control device (80) for starting the machine;
A factory air conditioner comprising: A second refrigerator (20) arranged in parallel with the first refrigerator with respect to the refrigerant flow by the circulation pump and cooling the water refrigerant together with the first refrigerator;
The control device includes a case where the detected thermal load is equal to or higher than the first level, and a time when the detected temperature of the water temperature detecting means is equal to or higher than a second cold water temperature equal to or higher than the first cold water temperature. The second refrigerator is stopped at any one time, the detected heat load is not less than the first level, and the detected temperature of the water temperature detecting means is not less than the second cold water temperature. The factory air conditioner according to claim 1, wherein the second refrigerator is activated at a certain time. An outside air temperature sensor (73) for detecting outside air;
The control device is configured such that when the detected heat load is less than the first level, when the detected temperature of the water temperature detecting means is less than a second cold water temperature, and when the detected temperature of the outside air sensor is the first outside air. The second refrigerator is stopped at at least one time when the temperature is lower than the temperature, the detected heat load is not less than the first level, and the detected temperature of the water temperature detecting means is the second temperature. 3. The factory air conditioner according to claim 2, wherein the second refrigerator is started when the temperature is equal to or higher than the cold water temperature and the detected temperature of the outside air sensor is equal to or higher than the first outside air temperature.

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