JP2009216321A - Freezing prevention control system and freezing prevention control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a freezing prevention control system maintaining a freezing prevention function of all outdoor units even in an air conditioning system equipped with a plurality of outdoor units in different installation situations, and allowing parallel usage with an electric power demand control. <P>SOLUTION: An air conditioning control part 8 controls an opening of a cold/hot water valve 12 for every outdoor unit 1 such that a temperature of cold/hot water flowing through a circulation piping 13 of an outdoor unit 1 outlet side is maintained at a freezing prevention set temperature. A fluctuation of a flow rate of the cold/hot water flowing from each cold/hot water valve 12 is measured by a flowmeter, and the air conditioning control part 8 increases a discharge pressure of a pump in proportion to the flow rate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a freeze prevention control system for a coil in an external air conditioner that performs heat exchange treatment between outside air intake air and circulating water flowing through a pipe.

  In an external air conditioner, a coil that exchanges heat between circulating water flowing through a pipe and outside air intake air may be frozen or ruptured due to a decrease in outside air temperature. In order to prevent freezing, for example, Patent Document 1 discloses a circulating water freeze prevention control device that monitors the circulating water temperature and adjusts the flow rate of the circulating water according to the circulating water temperature. This device controls a pump that circulates circulating water to increase the flow rate of the circulating water in inverse proportion to the circulating water temperature, thereby preventing freezing with the minimum necessary power consumption.

Japanese Utility Model Publication No. 1-100044

  Since the conventional circulating water freeze prevention control device is configured as described above, the opening degree control of the circulating water valve for adjusting the flow rate of the circulating water flowing to each external air conditioner is not performed. For this reason, there is a problem that a large amount of circulating water is required to flow the circulating water to all of the plurality of external air conditioners arranged in the pipe. In addition, since a large amount of circulating water flows, the power consumption of the pump increases. On the other hand, if the flow rate of circulating water is reduced for the purpose of reducing power consumption according to power demand control, depending on the installation status of the air conditioner (installation level, piping resistance, ambient temperature, etc.), all There is a problem that it is difficult to maintain the freeze prevention function of the external air conditioner.

  The present invention was made to solve the above-described problems, and maintains an anti-freezing function for all the external air conditioners, even in an air conditioning system including a plurality of external air conditioners with different installation conditions. It aims at realizing the freeze prevention control system which can be used together with demand control.

  A freeze prevention control system according to the present invention uses a cold / hot water thermometer that measures the temperature of cold / hot water in an external air conditioner, a cold / hot water valve that adjusts the flow of cold / hot water in the external air conditioner, and a cold / hot water thermometer. And an air conditioning controller that controls the opening degree of the cold / hot water valve for each external air conditioner according to the measured temperature of the cold / hot water.

  The freeze prevention control system according to the present invention includes an outside air thermometer for measuring the temperature of outside air, and the air conditioning control unit starts opening control of the cold / hot water valve when the temperature of the outside air falls below a predetermined value. It is a thing.

  In the freeze prevention control system according to the present invention, the air conditioning control unit controls the cold / hot water valve at a preset opening degree when a power demand control request is input from the outside.

  The anti-freezing control system according to the present invention measures a total flow rate of chilled / hot water adjusted by each chilled / hot water valve, a pump that supplies chilled / hot water to the external air conditioner, a discharge pressure adjusting unit that adjusts the discharge pressure of the pump The air conditioning control unit controls the discharge pressure adjusting unit so that the discharge pressure of the pump varies based on the total flow rate.

  The freeze prevention control method according to the present invention includes a temperature measurement step for measuring the temperature of cold / hot water flowing in the external air conditioner using a cold / hot water thermometer, and the temperature inside the external air conditioner based on the temperature measured in the temperature measurement step. The flow rate adjustment step for controlling the opening degree of the chilled water valve for adjusting the flow rate of the flowing chilled water for each external air conditioner, and the cooling temperature determined by the opening degree of the chilled water valve for each external air conditioner controlled in the flow rate adjustment step A discharge pressure adjusting step for adjusting the discharge pressure of the pump based on the total flow rate of water.

  According to this invention, the cold / hot water thermometer that measures the temperature of the cold / hot water of the external air conditioner, the cold / hot water valve that adjusts the flow of the cold / hot water of the external air conditioner, and the cold / hot water temperature measured using the cold / hot water thermometer. Since it is configured to include an air conditioning control unit that controls the opening degree of the cold / hot water valve for each external air conditioner according to the temperature of the water, even an air conditioning system including a plurality of external air conditioners with different installation conditions It is possible to realize an anti-freezing control system capable of suppressing power consumption while maintaining the anti-freezing function of all the external air conditioners.

Embodiment 1 FIG.
1 is a configuration diagram showing the configuration of an external air handler according to Embodiment 1 of the present invention. The outside air conditioner 1 shown in FIG. 1 takes in outside air from the direction of arrow 2 and supplies the outside air intake air subjected to heat exchange processing in the direction of arrow 3 on the indoor side as adjusted air. Description of the return air duct through which the air returning from the room passes is omitted. Outside air intake air taken into the external air conditioner 1 from the direction of the arrow 2 is introduced into the cold / hot water coil 5 via the filter 4. The cold / hot water coil 5 performs a heat exchange process between cold water or hot water (hereinafter referred to as cold / warm water) flowing through a circulation pipe 13 described later and this outside air intake air. The adjusted air heated or cooled by this process is adjusted in humidity by the humidifier 6 and discharged in the direction of arrow 3 by the fan 7. The operation of each unit of the external air conditioner 1 is controlled by the air conditioning control unit 8.

  The air conditioning control unit 8 includes a thermometer (outside air thermometer) 9 that measures the temperature of outside air or outside air intake air, and a thermometer (cold and hot water) that measures the temperature of cold / hot water flowing in the circulation pipe 13 on the outlet side of the external air conditioner. Thermometer) 10 is connected to monitor the outside air temperature and the cold / hot water temperature output from thermometers 9 and 10. In addition, the air conditioning control unit 8 controls the damper 11 installed in an outside air intake duct (not shown) to adjust the flow rate of the outside air intake air. Moreover, the flow rate of cold / hot water is adjusted by controlling the cold / hot water valve 12 interposed in the circulation pipe 13.

  FIG. 2 is a configuration diagram illustrating the overall configuration of the air conditioning system according to Embodiment 1 of the present invention. In the air conditioning system shown in FIG. 2, an air conditioning unit 100, a heat source unit 200, and a pump unit 300 are connected by a circulation pipe 13, and cold / hot water is circulated. A flow meter 14 is installed in the middle of the circulation pipe 13 connecting the air conditioning unit 100 and the heat source unit 200, and the flow rate of cold / hot water is measured.

  In FIG. 2, the air conditioning unit 100 includes the external air conditioners 1a, 1b, 1c, thermometers 10a, 10b, 10c, and cold / hot water valves 12a, 12b, 12c shown in FIG. Moreover, thermometers 9a, 9b, and 9c (not shown) for measuring the outside air temperature taken into the outside air conditioners 1a, 1b, and 1c are installed to measure each outside air temperature. In addition, in FIG. 2, the description of the air conditioner which heat-exchanges the air flow which is heat-exchange-processed, such as an external air intake duct, an air supply duct, and a return air duct, and the internal conditioner which supplies the heat-exchange-processed external air intake air indoors. Omitted.

  The heat source unit 200 is a primary pump 15a, 15b, 15c that sends cold / hot water after heat exchange with the outside air intake air in the external air conditioner 1 to the cold / hot heat source device 16 and a cold / hot water that produces the cold / hot water required by the air conditioning unit 100. It has heat source equipment 16a, 16b, 16c.

  The pump unit 300 includes headers 21 and 22 for controlling the amount of cold and hot water flowing through the circulation pipe 13, a bypass valve 17 interposed between the headers 21 and 22, and a plurality of circulation pipes arranged between the headers 21 and 22. 13 have secondary pumps 18a, 18b, 18c (pumps) disposed therein, and inverters 19a, 19b, 19c (discharge pressure adjusting units) for controlling the rotational speed of each secondary pump 18. The header 21 is provided with a pressure gauge 20 and measures the discharge pressure of cold / hot water discharged from the pump unit 300. The discharge pressure is controlled by adjusting the opening degree of the bypass valve 17 and the rotational speed of the secondary pumps 18a, 18b, 18c.

A connecting valve 24 interposed in the circulation pipe 13 that connects the header 22 and the header 23 adjusts the balance between the amount of cold / hot water flowing through the air conditioning unit 100 and the amount of cold / hot water flowing through the heat source unit 200.
The thermometer 10, the flow meter 14, and the pressure gauge 20 are each connected to the air conditioning control unit 8 and output measurement values. The air conditioning control unit 8 controls each unit of the air conditioning system using these measured values.

  In addition, if the external controller 1, the thermometers 9 and 10, the cold / hot water valve 12, the primary pump 15, the cold / hot heat source equipment 16, the secondary pump 18, and the inverter 19 determine the number of installation required by the design of an air conditioning system. Good. In addition, the air conditioning control unit 8 may be configured to be provided in one external air conditioner 1 or may be configured to be provided in an air conditioning system having a plurality of external air conditioners 1. In the following, in order to simplify the description, these parts are used one by one unless it is necessary to distinguish them.

Hereinafter, the operation of the freeze prevention control system will be described. FIG. 3 is a flowchart showing the operation of the freeze prevention control system according to Embodiment 1 of the present invention.
In step ST101, the air-conditioning control unit 8 activates the secondary pump 18 when the outside air temperature measured by the thermometer 9 becomes lower than a preset outside air temperature (outside air set temperature), and cool / warm water. The valve 12 is opened at the minimum set opening (for example, 10%), and the cold / hot water with the minimum flow rate is circulated in the circulation pipe 13 (step ST102). However, when the secondary pump 18 is already activated, the air conditioning control unit 8 controls only the opening degree of the cold / hot water valve 12.
The outside air set temperature may be a temperature (for example, 3 ° C.) at which the cold / hot water flowing in the cold / hot water coil 5 and the circulation pipe 13 of the external air conditioner 1 is not frozen, and may be a different temperature for each external air conditioner 1.

  In step ST103, the air-conditioning control unit 8 proceeds to the process of step ST104 when a preset time until the circulating pipe 13 reaches a uniform temperature regardless of the location has elapsed (step ST103 “Yes”). Note that the process of step ST103 is not essential, and the air conditioning control unit 8 may proceed to the process of step ST104 without waiting for the set time.

  In step ST104, the air conditioning control unit 8 proportionally controls the opening degree of the cold / hot water valve 12 so that the cold / hot water temperature measured by the thermometer 10 is maintained at the freeze prevention set temperature. Specifically, the thermometer 10 measures the cold / hot water temperature (temperature measurement step), and the air-conditioning control unit 8 controls the opening degree so that the cold / hot water temperature and the opening degree of the cold / hot water valve 12 are inversely proportional to each other. The flow rate in the pipe 13 is increased (flow rate adjustment step). The freeze prevention set temperature may be a temperature at which the cold / hot water does not freeze (for example, 1 ° C.), and may be a temperature different for each external air conditioner 1. Thereby, the flow rate of the cold / hot water flowing through the external air conditioner 1 can be adjusted according to the installation situation, and it is possible to prevent all the external air conditioners 1 from freezing. At this time, since only the minimum necessary flow rate is circulated through the circulation pipe 13, the conveyance power of the secondary pump 18 can be reduced.

  The flow rate that is changed by the control of the opening / closing of the hot / cold water valve 12 in step ST104 is measured by the flow meter 14 and output to the air conditioning control unit 8. When the hot / cold water flow rate measured by the flow meter 14 falls below the set minimum flow rate (step ST105 “Yes”), the air conditioning control unit 8 opens the bypass valve 17 in step ST106 and controls the inverter 19 to control the secondary pump. 18 is operated at the minimum rotational speed. By controlling the bypass valve 17 and the secondary pump 18, the cold / hot water flow rate is maintained above the set minimum flow rate.

When the air-conditioning control unit 8 confirms that the cold / hot water flow rate is equal to or higher than the set minimum flow rate in step ST107 (step ST107 “Yes”), in step ST108, the discharge pressure of the pump unit 300 is based on the cold / hot water flow rate. To set.
FIG. 4 is a graph showing an example of setting the discharge pressure according to Embodiment 1 of the present invention. In FIG. 4, the left vertical axis indicates the discharge set pressure of the pump unit 300, the right vertical axis indicates the number of operating the secondary pump 18 at the stage increase settings 1 and 2, and the horizontal axis is measured by the flow meter 14. Indicates the cold / hot water flow rate. The air conditioning controller 8 determines the discharge setting pressure so that the discharge pressure of the pump unit 300 becomes a value proportional to the cold / hot water flow rate measured by the flow meter 14 from the time when the cold / hot water flow rate exceeds the set minimum flow rate 40 ( Step ST108). As shown in FIG. 4, the air conditioning controller 8 controls the number of secondary pumps 18 by comparing the cold / hot water flow rate measured by the flow meter 14 with a preset increase / decrease stage flow rate.

  In step ST109, the air conditioning control unit 8 compares the discharge set pressure with the discharge pressure of the pump unit 300 measured by the pressure gauge 20. When the discharge pressure matches the discharge set pressure (step ST109 “Yes”), the air conditioning control unit 8 operates while maintaining the rotation speed of the secondary pump 18. On the other hand, when the discharge pressure does not coincide with the discharge set pressure (“No” in step ST109), the air conditioning control unit 8 controls the inverter 19 to increase or decrease the rotation speed of the secondary pump 18, and the discharge pressure is set to the discharge set pressure. To match. At this time, since only the minimum necessary flow rate is circulated through the circulation pipe 13, the conveyance power of the secondary pump 18 operating in the pump unit 300 can be reduced. Steps ST105 to ST111 are discharge pressure adjustment steps.

  As described above, according to the first embodiment, a plurality of external air conditioners 1 that supply air that has undergone heat exchange treatment between the outside air and the cold / hot water that circulates in the circulation pipe 13, and flow in the external air conditioner 1. A thermometer 10 for measuring the temperature of the cold / hot water, a cold / hot water valve 12 for adjusting the flow rate of the cold / hot water flowing in the external air conditioner 1, and an opening degree of the cold / hot water valve 12 according to the temperature of the cold / hot water. An air conditioning control unit 8 that controls every one is provided. Therefore, cold / hot water can be circulated with the minimum required flow volume according to the installation situation of each external air conditioner 1. Therefore, in the air conditioning system including a plurality of external air conditioners 1, all the external air conditioners 1 can be prevented from freezing.

  Further, according to the first embodiment, the secondary pump 18 that circulates the cold / hot water in the circulation pipe 13 and supplies the cold / hot water to the external controller 1, and the inverter 19 that adjusts the discharge pressure of the secondary pump 18, A flow meter 14 that measures the total flow rate of the chilled / hot water adjusted by the chilled / hot water valve 12, and the air-conditioning control unit 8 is an inverter so that the discharge pressure of the secondary pump 18 increases in proportion to the total flow rate. 19 and the number of secondary pumps 18 are controlled according to the total flow rate. Therefore, the conveyance power of the secondary pump 18 can be reduced. Therefore, power consumption of the air conditioning system can be suppressed.

  Further, according to the first embodiment, the outside air thermometer for measuring the temperature of the outside air is provided, and the air conditioning control unit 8 starts the opening degree control of the cold / hot water valve 12 when the outside air temperature falls below the outside air set temperature. I made it. Therefore, the freeze prevention control can be started only when the outside air temperature is low and there is a risk of freezing, and wasteful power consumption is not consumed.

Embodiment 2. FIG.
In the said Embodiment 1, it was set as the structure which suppresses power consumption by adjusting the cold / hot water flow volume which flows into each external air conditioner, respectively, and restrict | limiting to the minimum required flow volume. In the second embodiment, the freeze prevention control system is configured to suppress power consumption while maintaining the freeze prevention function of all the external air conditioners in response to a request for power demand control.

FIG. 5 is a configuration diagram illustrating a configuration of an air conditioning system according to Embodiment 2 of the present invention. The air conditioning system shown in FIG. 5 has a configuration in which a power meter 25 and a power demand control unit 26 are added to the air conditioning system shown in the first embodiment. In FIG. 5, the same or corresponding parts as those in FIG.
The wattmeter 25 shown in FIG. 5 measures the power consumption of a building or the like in which an air conditioning system is introduced, that is, a demand value, and outputs it to the power demand control unit 26. When the demand value exceeds preset power, the power demand control unit 26 outputs a power demand excess signal. The air conditioning control unit 8 that has received the power demand excess signal performs power demand control by limiting the power consumption of the air conditioning system.

Next, the operation of the power demand control of the air conditioning system performed by the air conditioning control unit 8 that has received the power demand excess signal when the power demand control unit 26 outputs the power demand excess signal will be described. FIG. 6 is a flowchart showing an example of the power demand control operation of the freeze prevention control system according to Embodiment 2 of the present invention.
In FIG. 6, when the power demand excess signal is input from the power demand control unit 26, the air conditioning control unit 8 compares the opening degree of the cold / hot water valve 12 with a preset power demand setting opening degree (step ST201). . A different value can be set for each external air conditioner 1 in the power demand setting opening. For example, for an external air conditioner for supplying air to a place where there is a high need for indoor temperature control, set a larger power demand setting opening degree for an air conditioner that supplies air to a place where the need is low. Set the power demand setting opening of a smaller value.

  In step ST201, when the opening degree of the cold / hot water valve 12 is equal to or larger than the power demand setting opening degree (step ST201 “Yes”), the air conditioning control unit 8 controls the opening degree of the cold / hot water valve 12 to be the power demand setting opening degree. (Step ST202). On the other hand, when the opening degree of the cold / hot water valve 12 is smaller than the power demand setting opening degree (step ST201 “No”), the air conditioning control unit 8 maintains the current opening degree of the cold / hot water valve 12 (step ST203).

Next, the operation of the freeze prevention control system will be described. FIG. 7 is a flowchart showing an example of the operation of the freeze prevention control system according to Embodiment 2 of the present invention.
In FIG. 7, when the cold / hot water valve 12 is not fully closed (0%) (step ST301 “Yes”) and the outside air temperature is equal to or higher than the outside air set temperature (eg, 3 ° C.) (step ST302 “Yes”), When a power demand excess signal is input from power demand controller 26 (step ST303 “Yes”), power demand control shown in FIG. 6 is started in step ST304.
When the outside air temperature is higher than the outside air set temperature in summer or the like, the cold / warm water is not likely to freeze, so the freeze prevention control is not performed. Therefore, after the power demand control is finished in step ST304 or when there is no power demand excess signal input (step ST303 “No”), the process returns to step ST301 again.

  On the other hand, in the winter season when the cold / hot water valve 12 is fully closed (step ST301 “No”) and the outside air temperature is equal to or lower than the outside air set temperature (step ST305 “Yes”), the cold / hot water coil 5 of the external air conditioner 1 and Since the cold / hot water flowing in the circulation pipe 13 may freeze, the air conditioning control unit 8 starts anti-freezing control. The air-conditioning control unit 8 starts the secondary pump 18, opens the cold / hot water valve 12 at the minimum setting opening (for example, 10%), and circulates the cold / hot water with the minimum flow rate in the circulation pipe 13 (step ST306). . However, when the secondary pump 18 is already activated, the air conditioning control unit 8 controls only the opening degree of the cold / hot water valve 12. When the outside air temperature is higher than the outside air set temperature (step ST305 “No”), the process returns to step ST301.

  In step ST307, the air-conditioning control unit 8 sets a preset time (for example, 5 minutes) until the circulating pipe 13 reaches a uniform temperature regardless of the location (step ST307 “Yes”), and then step ST311. Proceed to the process.

  On the other hand, when the outside air temperature is lower than the outside air set temperature (step ST302 “No”) in the situation where the air conditioner has already been activated in winter (step ST302 “No”), it is necessary to perform anti-freezing control. The air conditioning controller 8 compares the opening degree of the cold / hot water valve 12 with a minimum setting opening degree (for example, 10%) (step ST308). If the opening degree of the cold / hot water valve 12 is equal to or smaller than the minimum set opening degree as a result of the comparison (step ST308 “Yes”), the air conditioning control unit 8 moves the cold / hot water valve 12 to the minimum set opening degree to prevent freezing. Open (step ST309). On the other hand, if the opening degree of the cold / hot water valve 12 is larger than the minimum set opening degree as a result of the comparison (step ST308 “No”), there is no fear of freezing. Maintain the opening.

In step ST311, the air conditioning control unit 8 compares the cold / hot water temperature measured by the thermometer 10 with a freeze prevention set temperature (for example, 1 ° C.). As a result of the comparison, when the cold / hot water temperature is equal to or lower than the freeze prevention set temperature (step ST311 “Yes”), the air conditioning control unit 8 sets the cold / hot water valve 12 so that the cold / warm water temperature is maintained at the freeze prevention set temperature. Proportionally control the opening. Since this proportional control is the same as step ST104 in FIG. 3, description thereof is omitted.
As a result of the comparison, when the cold / hot water temperature is higher than the freeze prevention set temperature (step ST311 “No”), the process returns to step ST301.

After the proportional control in step ST312, even when a power demand excess signal is input from the power demand control 26 to the air conditioning control unit 8 (step ST313 "Yes"), the cold / hot water temperature is maintained at the freeze prevention set temperature. The air conditioning controller 8 continues the proportional control of the opening degree of the cold / hot water valve 12.
With the above control, when the demand value is predicted to exceed the set power, the opening degree of each cold / hot water valve is controlled so as to be equal to or less than the power demand setting opening degree for each air conditioner. The conveyance power of the secondary pump 18 can be reduced by limiting the flow rate of the cold / hot water flowing through the circulation pipe 13 while maintaining the indoor environment at a minimum. Therefore, power consumption of the air conditioning system can be suppressed. Note that power demand control is generally required in the summer and winter, but depending on the building application, power demand control may be required even in the intermediate period. Applicable.

As described above, according to the second embodiment, when the power demand excess signal is input from the power demand control unit 26 during the freeze prevention control, the freeze prevention control is given priority. The proportional control of the cold / hot water valve is performed so that the cold / hot water temperature is maintained at the anti-freezing set temperature every time, so that the necessary minimum opening degree can be suppressed and an excessive increase in demand can be suppressed. Moreover, the conveyance power of the secondary pump 18 can be reduced by limiting the flow rate of the cold / hot water flowing through the circulation pipe 13 to the minimum necessary. Therefore, to realize an anti-freezing control system that maintains the anti-freezing function of all external air conditioners and enables the combined use with power demand control even in an air conditioning system equipped with multiple external air conditioners with different installation conditions. Can do.
Also, in order to reduce power consumption, the operation of the external air conditioner 1 is not stopped, but the cold / hot water is circulated to each external air conditioner 1 at the opening degree of the cold / hot water valve 12 according to the importance. The environment can be maintained at a minimum.

  In Embodiment 2 above, in steps ST201 and ST202, the chilled / hot water valve 12 of each external air conditioner 1 is controlled to be equal to or less than the power demand set opening, but the adjusted air sent by the external air conditioner 1 is used. A configuration may be adopted in which the set temperature of the internal conditioner that supplies the air to the room is shifted higher by a preset value. Furthermore, the preset value may be a value that differs for each internal adjuster depending on the importance. In the case of this configuration, when the set temperature of the internal air conditioner becomes high, the cold / hot water flowing through the external air conditioner 1 decreases, and as a result, the flow rate of the cold / hot water flowing through the circulation pipe 13 is limited. Therefore, even in this configuration, the indoor environment can be maintained at a minimum, and the power consumption of the air conditioning system can be suppressed.

It is a block diagram which shows the structure of the external air handler which concerns on Embodiment 1 of this invention. It is a block diagram explaining the whole structure of the air conditioning system which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the freeze prevention control system which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the freeze prevention control system which concerns on Embodiment 1 of this invention. It is a graph which shows the example of a setting of the discharge pressure which concerns on Embodiment 1 of this invention. It is a block diagram explaining the structure of the air conditioning system which concerns on Embodiment 2 of this invention. It is a flowchart which shows one example of the electric power demand control operation | movement of the freeze prevention control system which concerns on Embodiment 2 of this invention. It is a flowchart which shows one example of operation | movement of the freeze prevention control system which concerns on Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 External controller 2, 3 Arrow 4 Filter 5 Cold / hot water coil 6 Humidifier 7 Fan 8 Air-conditioning control part 9,10 Thermometer 11 Damper 12 Cold / hot water valve 13 Circulation piping 14 Flow meter 15 Primary pump 16 Cold / hot heat source equipment 17 Bypass Valve 18 Secondary pump 19 Inverter 20 Pressure gauge 21, 22, 23 Header 24 Connection valve 25 Power meter 26 Power demand control unit 40 Minimum set flow rate 100 Air conditioning unit 200 Heat source unit 300 Pump unit

Claims (5)

In the anti-freezing control system for preventing freezing of the cold / hot water in a plurality of external air conditioners that exchange heat between the cold / hot water flowing inside and the outside air,
A cold / hot water thermometer for measuring the temperature of the cold / hot water of the external controller;
A cold / hot water valve for adjusting a flow rate of the cold / hot water of the external controller;
An anti-freezing control system comprising: an air conditioning control unit that controls an opening degree of the cold / hot water valve for each external controller in accordance with the temperature of the cold / hot water measured using the cold / hot water thermometer. An outside air thermometer that measures the temperature of the outside air
The anti-freezing control system according to claim 1, wherein the air conditioning control unit starts opening control of the cold / hot water valve when the temperature of the outside air falls below a predetermined value.   The anti-freezing control system according to claim 1 or 2, wherein the air-conditioning control unit controls the cold / hot water valve at a preset opening degree when a power demand control request is input from the outside. . A pump for supplying cold and hot water to the external air conditioner;
A discharge pressure adjusting unit for adjusting the discharge pressure of the pump;
A flow meter for measuring the total flow of the cold / hot water adjusted by each cold / hot water valve,
The air conditioning control unit controls the discharge pressure adjusting unit so that the discharge pressure of the pump varies based on the total flow rate. Anti-freezing control system. Cooling / warm water freezing control in an air conditioning system that supplies chilled / warm water to each of the plurality of external air conditioners by pumps, exchanges heat between the chilled / warm water flowing in the plurality of external air conditioners and the outside air, and sends out regulated air In the anti-freezing control method to be performed,
A temperature measurement step of measuring the temperature of the cold / hot water flowing in the external air conditioner using a cold / hot water thermometer;
Based on the temperature measured in the temperature measurement step, a flow rate adjustment step for controlling the opening degree of the cold / hot water valve for adjusting the flow rate of the cold / hot water flowing in the external air conditioner for each external air conditioner;
A discharge pressure adjusting step for adjusting the discharge pressure of the pump to vary based on the total flow rate of the cold / hot water determined by the opening degree of the cold / hot water valve for each external controller controlled in the flow rate adjusting step; A freeze prevention control method comprising:

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