JP5940608B2 - Heat medium circulation system - Google Patents

Description

  The present invention relates to a heat medium circulation system that circulates a heat medium that moves heat generated by a heat source device.

For example, in the cold water circulation system described in Patent Document 1, cold water generated by a refrigerator is circulated through a cooling heat exchanger to cool a cooling object such as room air. The chilled water circulation system controls the cooling capacity exhibited by the cooling heat exchanger by adjusting the amount of chilled water circulated by a flow rate adjusting valve such as a control two-way valve.

Japanese Patent No. 4333818

When the cooling capacity required by the cooling heat exchanger increases, the chilled water circulation system increases the amount of chilled water to be circulated by increasing the opening of the flow rate adjustment valve accordingly. When the cooling capacity required for the cooling heat exchanger decreases, the cold water circulation system reduces the amount of cold water to be circulated by reducing the opening of the flow rate adjustment valve accordingly.

For this reason, when the cooling capacity required for the heat exchanger for cooling is small, the opening degree of the flow regulating valve is small. Therefore, the pressure loss generated in the flow rate adjustment valve becomes larger than when the required cooling capacity is large. That is, in the chilled water circulation system, when the required cooling capacity is small, the power consumption (power consumption) required by the pump device for circulating the chilled water is increased.

  An object of this invention is to provide the cold water circulation system which can reduce power consumption in view of the said point.

In order to achieve the above object, the present invention provides a plurality of heat exchangers for exchanging heat between a heat medium and a target in a heat medium circulation system that circulates a heat medium that moves heat generated by a heat source device (7). (5A), a pump device (P2) that circulates the heat medium, and a plurality of flow rate adjustment valves provided corresponding to each of the plurality of heat exchangers (5A), the heat exchanger (5A) A plurality of flow rate adjustment valves (5B) for adjusting the amount of supplied heat medium, and a plurality of flow rate adjustment valves (5B), each of which detects an opening degree and outputs an opening degree signal indicating the detected opening degree. The degree detection unit (S4) and a control unit to which at least an opening degree signal is input, and control capable of controlling the operation of the pump device (P2) and the opening degree of the flow rate adjusting valve (5B) in the power saving control mode. Part (10, 10A, 10B) Control mode, at least one flow control valve of the plurality of flow rate adjusting valve (5B) (hereinafter, the particular control valve (5BS) of. The flow rate adjustment valve) the opening of, before performing the power-saving control mode And a pump operation changing function for changing and controlling the operation of the pump device (P2) based on the opening change of the specific control valve (5Bs).

  Accordingly, in the present invention, the opening degree of the specific control valve (5Bs) is increased and the operation of the pump device (P2) is changed according to the increased opening degree, so that the necessary amount of circulating heat medium is secured. The pressure loss generated in the flow rate adjusting valve (5B) can be reduced. Therefore, it is possible to obtain a cold water circulation system capable of reducing power consumption.

  In addition, when changing and controlling the operation of the pump device (P2), the pump device (P2) is controlled so that the circulating heat medium amount is the same as that before the opening degree of the specific control valve (5Bs) is changed. It is desirable.

  Incidentally, the reference numerals in parentheses for each of the above means are examples showing the correspondence with the specific means described in the embodiments described later, and the present invention is indicated by the reference numerals in the parentheses of the above respective means. It is not limited to specific means.

It is a figure showing an outline of an air-conditioning system concerning an embodiment of the present invention. It is a figure which shows the outline | summary of the control system of the air conditioning system which concerns on embodiment of this invention. It is explanatory drawing of the cooling tower 7B which concerns on embodiment of this invention. It is a flowchart which shows the control which concerns on 1st Embodiment of this invention. It is a flowchart which shows the control which concerns on 2nd Embodiment of this invention.

  The “embodiment of the invention” described below shows an example of the embodiment. In other words, the invention specific items described in the claims are not limited to the specific means and structures shown in the following embodiments.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that at least one member or part described with at least a reference numeral is provided, except for cases where “plural”, “two or more” and the like are omitted.

(First embodiment)
1. 1. Configuration of air conditioning system 1.1 Outline of air conditioning system In the present embodiment, the heat medium circulation system according to the present invention is applied to an air conditioning system that performs air conditioning in a server room, a communication equipment room, and the like. That is, the air conditioning system according to the present embodiment cools a plurality of ICT devices and the like by supplying cooling air to heat-generating devices such as information communication technology devices (hereinafter referred to as ICT devices).

  As shown in FIG. 1, the plurality of ICT devices 1 are installed in a data center room or the like in a state assembled to the rack 3. The rack 3 is configured by a frame-shaped storage shelf in which a metal shelf frame and a column wall are combined.

  One side of the rack 3 is provided with a cold air passage (cold aisle) 3A to which cold air is supplied. The cool air is supplied from the duct space 3C provided under the floor of the cool air passage 3A to the rack 3 side, and then supplied to the cool air passage 3A from a plurality of cold air outlets (not shown) provided on the floor.

  A cold air outlet is not provided in the passage 3B opposite to the cold air passage 3A across the rack 3. In the passage 3B, air supplied from the cold air passage 3A to the ICT device 1 and having undergone heat exchange with the ICT device 1 flows. That is, the passage 3B is a hot air passage (hot aisle) through which heated air (hot air) flows.

  The air conditioning unit 5 generates cooling air supplied to the ICT equipment 1 side. In a server room or the like in which a plurality of ICT devices 1 are installed, at least one (two in FIG. 1) air conditioning unit 5 is installed.

  As shown in FIG. 2, each air conditioning unit 5 is configured by an air handling unit (AHU) having an indoor heat exchanger 5A, a flow rate adjusting valve 5B, an indoor blower 5C, and the like. The indoor heat exchanger 5A exchanges heat between the cold water supplied from the heat source device 7 and the air that forms the heat exchange target.

  The heat source device 7 generates cold heat. The cold heat is supplied to the indoor heat exchanger 5A by cold water as a heat medium. The heat medium, that is, cold water is supplied to the indoor heat exchanger 5A (the air conditioning unit 5) by the primary pump P1 and the secondary pump P2.

  The flow rate adjusting valve 5B is provided in each indoor heat exchanger 5A. The flow rate adjusting valve 5B adjusts the amount of chilled water supplied to the indoor heat exchanger 5A. The indoor blower 5C is a blower capable of supplying cold air to the ICT device 1 side and adjusting the air volume.

  The heat source device 7 is installed outdoors. The cold water generated by the heat source device 7 is supplied to the indoor (air conditioning unit 5) side by the primary pump P1, and then distributed and supplied to each air conditioning unit 5 by the secondary pump P2.

  The bypass flow path L1 is a chilled water circuit that absorbs a flow rate difference when the discharge flow rate of the primary pump P1 and the discharge flow rate of the secondary pump P2 are different. For example, when the opening degree of the flow rate adjustment valve 5B becomes small and the discharge flow rate of the secondary pump P2 decreases, the reduced amount flows through the bypass flow path L1.

  The heat source device 7 includes a heat source machine 7A, a cooling tower 7B, a cooling water pump P3, and the like. The heat source unit 7A is configured by a vapor compression refrigerator that circulates a refrigerant such as chlorofluorocarbon to move the heat on the low temperature side to the high temperature side.

  The cooling tower 7B cools the cooling water by exchanging heat between the cooling water heat-exchanged with the refrigerant and at least one of air and water. The cooling tower 7B according to the present embodiment is a hermetic cooling tower as shown in FIG. The cooling tower 7B is provided with an outdoor fan 7C, a sprinkler 7D, an outdoor heat exchanger 7E, and the like.

  The outdoor heat exchanger 7E mainly exchanges heat between the atmosphere and the cooling water. The outdoor blower 7C is a blower that can blow air to the outdoor heat exchanger 7E and adjust the amount of blown air. For this reason, if the rotation speed of the outdoor blower 7C is increased or decreased to increase or decrease the amount of air flow, the heat exchange capacity between the cooling water and the atmosphere can be increased or decreased.

  The water sprinkler 7D sprinkles water to the outdoor heat exchanger 7E. When water is sprinkled on the outdoor heat exchanger 7E, the sprinkled water absorbs heat from the outdoor heat exchanger 7E and evaporates or rises in temperature. Thereby, a cooling water is cooled largely compared with the case where watering is not carried out. That is, by controlling the operation of the sprinkler 7D, the heat exchange capacity between the cooling water and the atmosphere can be adjusted.

1.2 Air Conditioning System Capacity Adjustment Device The heat exchange capacity generated in the indoor heat exchanger 5A, that is, the cooling capacity generated in the indoor heat exchanger 5A is determined by the opening degree of the flow rate adjustment valve 5B, the air flow rate of the indoor fan 5C, It varies depending on the amount of cold water supplied to the heat exchanger 5A (the amount of water delivered by the secondary pump P2) and the temperature of the cold water (the refrigeration capacity generated by the heat source device 7).

  The refrigerating capacity generated in the heat source device 7, that is, the refrigerating capacity generated in the heat source unit 7A (vapor compression type refrigerating machine) is added to the cooling capacity of the cooling tower 7B, the circulating water amount of the cooling water, etc. It varies depending on the rotational speed of the provided compressor and the opening degree of the expansion valve. The cooling capacity of the cooling tower 7B varies depending on the amount of air blown by the outdoor blower 7C and the amount of water sprayed by the water sprinkler 7D.

  That is, the flow rate adjusting valve 5B, the indoor blower 5C, the secondary pump P2, the cooling water pump P3, the outdoor blower 7C, the sprinkler 7D, and the like function as a capacity adjusting device that adjusts the heat exchange capacity generated in the indoor heat exchanger 5A. To do. Hereinafter, when the flow rate adjusting valve 5B, the indoor blower 5C, and the like are collectively referred to as a capacity adjusting device.

  As shown in FIG. 2, the operation of the capacity adjusting device is controlled by the integrated control device 10. The integrated control device 10 is a capacity adjustment device via an air conditioner control unit 10A, a secondary pump control unit 10B, a primary pump control unit 10C, a heat source control unit 10D, a cooling water pump control unit 10E, and a cooling tower control unit 10F. Indirect control of each device constituting the.

  The air conditioner control unit 10A controls the operation of the air conditioning unit 5, that is, the flow rate adjusting valve 5B, the indoor blower 5C, and the like. The secondary pump control unit 10B controls the amount of cold water supplied to the air conditioning unit 5 by controlling the operation of the secondary pump P2.

  The primary pump control unit 10C controls the operation of the primary pump P1. The heat source control unit 10D controls the heat source unit 7A, that is, the rotational speed of the compressor, the opening degree of the expansion valve, and the like. The cooling water pump control unit 10E controls the operation of the cooling water pump P3 to control the circulation amount of the cooling water. The cooling tower control unit 10F controls the amount of air blown by the outdoor fan 7C, the amount of water sprayed by the water sprinkler 7D, and the like.

  The integrated control device 10 and the control units 10A to 10F are configured by including a computer having a CPU, a ROM, a RAM, and the like. A program for executing the control is stored in advance in a nonvolatile storage unit such as a ROM provided in the integrated control device 10 and the control units 10A to 10F.

2. 2.1 Control action by integrated control device 2.1 Outline of control action <Autonomous control of each control unit>
Each of the control units 10A to 10F includes a drive circuit that drives a control target of the control unit, and directly controls the control target. The integrated control device 10 issues a control command signal to each of the control units 10A to 10F.

  That is, after receiving the control command signal from the integrated control device 10, each of the control units 10A to 10F autonomously executes specific control for realizing the content of the control command signal. The integrated control device 10 and the control units 10A to 10F can execute at least a normal control mode and a power saving control mode as control modes.

  For example, each air conditioning unit 5 is provided with a blown air temperature sensor S1. The blown air temperature sensor S1 detects the temperature of the air supplied indoors from the air conditioning unit 5, that is, the temperature of the air for which heat exchange has been completed in the indoor heat exchanger 5A (hereinafter referred to as temperature after heat exchange).

  In the normal control mode, the air conditioner control unit 10A is configured so that the post-heat exchange temperature detected by the blown air temperature sensor S1 (hereinafter referred to as blown air temperature) The flow rate adjusting valve 5B and the indoor blower 5C are controlled so that the temperature after heat exchange (hereinafter referred to as the target blowing temperature Tao) is achieved.

  That is, the air conditioner control unit 10A autonomously controls the operation of the air conditioning unit 5 so as to be the current target blowing temperature Tao unless the new target blowing temperature Tao is set by the integrated control device 10.

  Specifically, the air conditioner control unit 10A increases the flow rate of the chilled water supplied to the indoor heat exchanger 5A by increasing the opening degree of the flow rate adjustment valve 5B as the target blowing temperature Tao decreases, and the target blowing temperature The higher the temperature Tao is, the smaller the flow rate of the cold water supplied to the indoor heat exchanger 5A is decreased by decreasing the opening degree of the flow rate adjusting valve 5B.

  Note that the air conditioner control unit 10A according to the present embodiment does not uniquely determine the opening degree of the flow rate adjustment valve 5B with respect to the target blowing temperature Tao. That is, the air conditioner control unit 10A monitors the current blown air temperature (the detected temperature of the blown air temperature sensor S1), and adjusts the flow rate adjustment valve 5B so that the current blown air temperature and the target blown temperature Tao are reduced. Change the opening sequentially.

  The air conditioner control unit 10A, when it is necessary to rapidly reduce the temperature in the server room (room temperature), that is, as the value obtained by subtracting the target blowing temperature Tao from the current blowing air temperature increases, Increase air flow.

  In addition, if the amount of blown air increases while the temperature and flow rate of the cold water supplied to the indoor heat exchanger 5A (the opening degree of the flow rate adjustment valve 5B) are constant, the blown air temperature rises. For this reason, 10 A of air conditioner control parts enlarge the opening degree of the flow regulating valve 5B according to the increase in ventilation volume so that the blowing air temperature may be maintained at the target blowing temperature Tao.

  In the normal control mode, the primary pump control unit 10C and the secondary pump control unit 10B are set to a preset flow rate (hereinafter referred to as a target chilled water circulation amount Wro) unless a flow rate change command is received from the integrated control device 10. ) Autonomously controls the primary pump P1 and the secondary pump P2 so that the cold water circulates.

  When the primary pump control unit 10C and the secondary pump control unit 10B receive the flow rate change command from the integrated control device 10 in the normal control mode, the received new circulation amount is set as the target chilled water circulation amount Wro. The primary pump P1 and the secondary pump P2 are autonomously controlled.

  On the discharge side of the primary pump P1 or the secondary pump P2 (primary pump P1 in this embodiment), a cold water temperature sensor S2 for detecting the temperature of the cold water is provided. In the normal control mode, the heat source control unit 10 </ b> D sets the “target chilled water discharge temperature” set by the integrated control device 10 as the chilled water temperature detected by the chilled water temperature sensor S <b> 2 (hereinafter referred to as chilled water discharge temperature). (Hereinafter, it is referred to as the target cold water temperature Two.) "

  That is, the heat source control unit 10D autonomously controls the operation of the heat source unit 7A so as to be the current target cold water temperature Two, unless the new target cold water temperature Two is set by the integrated control device 10.

  In the normal control mode, the cooling water pump control unit 10E sets the circulation amount of the cooling water “target circulation amount of cooling water (hereinafter referred to as target circulation amount Wfo)” set by the integrated control device 10. The cooling water pump P3 is controlled so that

  In the cooling tower control unit 10F, the temperature of the cooling water cooled in the cooling tower 7B is “target cooling water temperature (hereinafter referred to as target cooling water temperature Tco)” set by the integrated control device 10. The cooling tower 7B is controlled so that it becomes. The “cooling water temperature” is detected by the cooling water temperature sensor S3.

  In the normal control mode, if the chilled water discharge temperature cannot be cooled to the target chilled water temperature Two by only controlling the heat source unit 7A, the integrated control device 10 controls the cooling water pump control unit 10E and the cooling tower control. A command for increasing the target circulation amount Wfo or a command for decreasing the target cooling water temperature Tco is issued to at least one of the sections 10F.

2.2 Power saving control and margin <Power saving control mode>
The power saving control mode is a control for reducing the power consumption of the air conditioning system by increasing the opening of the flow rate adjusting valve 5B and reducing the load (discharge pressure) of the secondary pump P2 as compared with the normal control mode. Mode.

Specifically, in the power saving control mode, (1) the opening degree of at least one flow rate adjusting valve (hereinafter, the flow rate adjusting valve is referred to as a specific control valve 5Bs) among the plurality of flow rate adjusting valves 5B. Before executing the control mode, that is, compared with the normal control mode, the function is increased (hereinafter, this function is referred to as an opening changing function), and (2) at least secondary based on the opening change of the specific control valve 5Bs. The operation of the pump P2 is changed and controlled (hereinafter, this function is referred to as a pump operation changing function).

  The integrated control device 10 determines the opening degree of the flow rate adjusting valve 5B based on the opening degree signal output from the opening degree detection unit S4 configured by a potentiometer or the like. When the opening degree changing function is executed, the opening degree of the specific control valve 5Bs is controlled to be equal to or more than a preset opening degree. The opening signal is input to the integrated control device 10 via the air conditioner control unit 10A.

  During the pump operation changing function, the secondary pump P2 is controlled so that the circulating chilled water amount is the same as that before the opening degree of the specific control valve 5Bs is changed. That is, in the power saving control mode, the integrated control apparatus 10 issues a command to increase the opening degree of the specific control valve 5Bs to the air conditioner control unit 10A after selecting the specific control valve 5Bs.

  Thereby, in the secondary pump control part 10B, since the autonomous control function which maintains the present amount of cold water circulation works, the rotation speed (discharge pressure) of the secondary pump P2 falls. At this time, the secondary pump control unit 10B gradually reduces the rotational speed (discharge pressure) of the secondary pump P2 within a predetermined change range based on the opening change of the specific control valve 5Bs. .

  Further, the secondary pump control unit 10B is configured so that the rotation speed (discharge pressure) of the secondary pump P2 is within a range in which the pressure at a part that is a predetermined dimension or more away from the discharge unit of the secondary pump P2 is equal to or higher than a preset lower limit pressure. Is gradually reduced.

  “Pressure at a site separated by a predetermined dimension or more from the discharge portion” is intended to be a so-called “end pressure”. That is, as the indoor heat exchanger 5A farther from the secondary pump P2, the amount of circulating cold water becomes smaller due to the influence of pressure loss. For this reason, in order to ensure the necessary amount of circulating cold water, it is necessary to maintain the “end pressure” at or above a predetermined pressure.

  In addition, “terminal pressure (pressure at a part away from the discharge part by a predetermined dimension or more)” is, of course, the pressure at the part actually located at the terminal, “estimated using“ pipe length, flow rate, etc. ” Any of “pressure” may be used.

  In the present embodiment, a flow meter or the like that directly detects the chilled water circulation amount is not provided. Therefore, in the present embodiment, the relationship between the rotational speed (discharge pressure) of the secondary pump P2, the opening degree of the flow rate adjustment valve 5B, and the amount of chilled water is obtained in advance by testing, and the secondary pump P2 is used by using the test result. The number of revolutions (discharge pressure) is estimated.

The integrated control device 10 selects the specific control valve 5Bs according to the following rules. That is, among the plurality of flow control valve 5B, to select at least one particular control valve from the flow rate adjusting valve the opening is in the preset below opening.

The integrated control apparatus 10 according to the present embodiment selects the flow rate adjustment valve having the largest opening degree as the specific control valve 5Bs among the “ flow rate regulating valves whose opening degree is less than the preset opening degree”. . That is, in the power saving control mode according to the present embodiment, one flow rate adjustment valve 5B is selected as the specific control valve 5Bs.

And the integrated control apparatus 10 performs a power saving control mode for every predetermined period set in advance as a general rule. However, the power saving control mode is not executed in the following cases.
That is, (1) when the margin A relating to any one of the plurality of indoor heat exchangers 5A under the control of the integrated control device 10 is equal to or less than a preset warning threshold, Do not execute the power control mode. Details of the margin A will be described later.

  (2) The number of flow rate adjustment valves 5B in which the opening degree of the flow rate adjustment valve 5B is greater than or equal to a preset opening degree (hereinafter referred to as a limit opening degree) is greater than or equal to a preset limit number. Sometimes, the power saving control mode is not executed.

  “Do not execute the power saving control mode” means that (a) before the power saving control mode is executed (in the normal control mode), even if the next power saving control mode execution timing comes, When the mode is not executed, and (b) during the execution of the power saving control mode, it means either the case where the power saving control mode is stopped or stopped.

  The limit opening and the limit number according to the present embodiment are determined and changed by the integrated control device 10 based on the cooling capacity (hereinafter referred to as an air conditioning load) required for the indoor heat exchanger 5A. That is, the limit opening and the limit number indicate conditions for stopping the power saving control mode.

  Since the opening degree of the flow rate adjusting valve 5B is increased in the power saving control mode, the margin A tends to decrease in the power saving control mode, as shown in Equation 1 described later. Therefore, in the embodiment, when the increase rate of the air conditioning load is positive, the limit opening and the limit number are made smaller than when the increase rate of the air conditioning load is negative.

  In the present embodiment, the air conditioning load is determined using the temperature difference between the detected temperature of the blown air temperature sensor S1 and the target blown temperature Tao. That is, the integrated control device 10 determines that the air conditioning load is larger as the value obtained by subtracting the target blowing temperature Tao from the detected temperature of the blowing air temperature sensor S1 is larger.

<Degree>
The margin A is a parameter relating to the difference between the maximum heat exchange capability adjustable by the capability adjustment device and the actual heat exchange capability. In the present embodiment, even when each device is controlled by autonomous control in the normal control mode, the margin A for each device is controlled so as to be maintained at a predetermined value or more.

For example, the margin A for the air conditioning unit 5 is defined by one of the following.
(1) 1- (Average opening degree of a plurality of flow control valves 5B)
(2) 1-{(average of actual number of revolutions of indoor fan 5C / maximum number of revolutions of indoor fan 5C)}
Maximum number of rotations: upper limit number of rotations of each indoor fan 5C (3) 1 / {(average of blown air temperature-target blown temperature Tao)}
(4) 1-{(average of blown air temperature-target blow temperature Tao)} / n
n: A value corresponding to (blow air temperature−target blow temperature Tao), which is a preset value, that is, n means an allowable temperature difference (allowable deviation temperature).
(5) 1 / {(average of cold water discharge temperature−target cold water temperature Two)}
(6) 1-{(average of cold water discharge temperature−target cold water temperature Two)} / n
n: A value corresponding to (cold water discharge temperature−target cold water temperature Two), which is a preset value, that is, n means an allowable temperature difference (allowable deviation temperature).

2.3 Details of Control Operation FIG. 4 shows a control flow in the power saving control mode. A program for executing this control is stored in advance in a nonvolatile storage unit such as a ROM provided in the integrated control apparatus 10. The program is executed by the CPU of the integrated control apparatus 10.

  This control is activated simultaneously with the activation of the air conditioning system. When this control is activated, it is first determined whether or not a predetermined time has elapsed since the previous power saving control mode was executed or the air conditioning system was activated (S1).

  If it is determined that the predetermined time has not elapsed (S1: NO), S1 is executed again. When it is determined that the predetermined time has elapsed (S1: YES), the limit opening and the limit number are set (S3, S5).

  Next, after the specific control valve 5Bs is selected from the plurality of flow rate adjustment valves 5B (S7), the air conditioning zone that the air conditioning unit 5 (indoor heat exchanger 5A) having the selected specific control valve 5Bs serves is selected. A margin A is calculated (S9).

  It is determined whether the margin A calculated in S9 is greater than or equal to the warning threshold (S11). If it is determined that the margin A is less than the warning threshold value (S11: NO), the discharge pressure (rotation speed) of the secondary pump P2 is increased and changed by a predetermined value (S13), and then S1. Is executed.

  When it is determined that the margin A is greater than or equal to the warning threshold value (S11: YES), the opening degree (X%) of the flow rate adjustment valve 5B is greater than or equal to the limit opening degree (X). It is determined whether the number is equal to or greater than the limit number Nmax (S15).

  When it is determined that the number Nmax of the flow rate adjusting valves 5B that are equal to or greater than the limit opening (X) is equal to or greater than the limit number (S15: YES), S1 is executed. When it is determined that the number Nmax of the flow rate adjusting valves 5B that are equal to or greater than the limit opening (X) is less than the limit number (S15: NO), the opening of the specific control valve 5Bs is equal to or less than full open. In addition, the discharge pressure of the secondary pump P2 is reduced so that the current amount of chilled water circulation is maintained while being set to an opening greater than the limit opening (X) (S17).

3. Features of the air-conditioning system according to the present embodiment In the present embodiment, the opening of the specific control valve 5Bs is increased and the operation of the secondary pump P2 is changed according to the increased opening. While ensuring, the pressure loss which generate | occur | produces in the flow regulating valve 5B can be reduced. Therefore, it is possible to obtain a cold water circulation system capable of reducing power consumption.

(Second Embodiment)
The “power saving control mode” according to the present embodiment is “(a) a total opening value or an average opening value obtained by integrating the opening amounts of the plurality of flow rate adjusting valves 5B, or a maximum opening amount among the plurality of flow rate adjusting valves 5B. (B) The operation of the secondary pump P2 and the opening degree of the flow rate adjustment valve 5B are controlled so that the degree is equal to or greater than a predetermined value.

  That is, unless the integrated control device 10 issues a command to change the target outlet temperature Tao to the air conditioner control unit 10A, the air conditioner control unit 10A executes autonomous control for maintaining the current amount of chilled water circulation.

  For this reason, the integrated control device 10 does not issue a command to change the target outlet temperature Tao to the air conditioner control unit 10A, and gives a command to the secondary pump control unit 10B to reduce the discharge pressure of the secondary pump P2. Then, the air conditioner control unit 10A increases the opening degree of the flow rate adjustment valve 5B in order to maintain the current amount of cold water circulation.

  Therefore, in the present embodiment, the total opening or the average opening obtained by integrating the opening of the plurality of flow control valves 5B, or the maximum opening among the plurality of flow control valves 5B is equal to or greater than a predetermined value. Until the discharge pressure of the secondary pump P2 is reduced.

  That is, FIG. 5 shows a control flow in the power saving control mode according to the present embodiment. A program for executing this control is stored in advance in a nonvolatile storage unit such as a ROM provided in the integrated control apparatus 10. The program is executed by the CPU of the integrated control apparatus 10. FIG. 5 shows an example in which “the average opening of the openings of the plurality of flow rate adjusting valves 5B” is used.

  This control is activated simultaneously with the activation of the air conditioning system. When this control is activated, it is first determined whether or not the predetermined time has elapsed since the previous power saving control mode was executed or the air conditioning system was activated (S21).

  If it is determined that the predetermined time has not elapsed (S21: NO), S1 is executed again. When it is determined that the predetermined time has elapsed (S21: YES), the flow rate adjustment valve 5B that satisfies the following exclusion requirements among the plurality of flow rate adjustment valves 5B has a total opening amount or an average opening amount obtained by integrating the opening amounts. Is excluded from the flow rate adjustment valve 5B which is a target when calculating the value of (S23).

  The “exclusion requirement” is “(a) the indoor heat exchanger 5A corresponding to the indoor fan 5C in which the air flow rate is equal to or less than a predetermined air flow rate, and (b) supplied to the indoor heat exchanger 5A. The opening degree of the flow rate adjusting valve 5B that adjusts the amount of chilled water is equal to or greater than a predetermined opening degree.

  Next, it is determined whether or not the value of the average opening degree of the flow rate adjustment valves 5B that are not to be excluded among the plurality of flow rate adjustment valves 5B is greater than or equal to a predetermined target value (S25). When the average opening value is equal to or greater than the target value (S25: YES), S1 is executed after the discharge pressure (rotation speed) of the secondary pump P2 is increased by a predetermined range (S29). .

When the value of the average opening is less than the target value (S25: NO), S1 is executed after the discharge pressure (rotation speed) of the secondary pump P2 is lowered by a predetermined range (S27).
As described above, also in the present embodiment, the opening degree of the flow rate adjusting valve 5B is increased and the operation of the secondary pump P2 is changed according to the increased opening degree, so that the necessary amount of circulating cold water is secured. The pressure loss generated in the flow rate adjusting valve 5B can be reduced. Therefore, it is possible to obtain a cold water circulation system capable of reducing power consumption.

  In the present embodiment, the opening degree of the flow rate adjusting valve 5B is autonomously changed by changing the discharge pressure of the secondary pump P2, but the present embodiment is limited to this. For example, the discharge pressure of the secondary pump P2 may be controlled to decrease autonomously by changing the average opening degree of the flow rate adjusting valve 5B to a predetermined opening degree or more.

(Other embodiments)
In the above-described embodiment, one flow rate adjustment valve 5B is provided in one indoor heat exchanger 5A. However, the present invention is not limited to this, and a plurality of indoor heat exchangers 5A are provided. One flow rate adjusting valve 5B may be provided. That is, the amount of cold water supplied to the plurality of indoor heat exchangers 5A may be controlled by one flow rate adjusting valve 5B.

  In the above-described embodiment, the present invention has been described by taking a plurality of air conditioning units 5 (indoor heat exchanger 5A) installed in the same room as an example. However, the present invention is not limited to this, for example, a plurality of air conditioning units 5 The present invention can be applied when there is a server room and at least one indoor heat exchanger 5A is installed in each server room.

  In the above-described embodiment, the present invention is suitable for an air conditioning system using only cold heat, but the application of the present invention is not limited to this, and the present invention is also applied to an air conditioning system that can also use hot and cold heat. it can.

  In the above-described embodiment, water is used as the heat medium, and the heat exchange target is air. However, the application of the present invention is not limited to this. For example, the heat exchange target is a coolant, and The present invention can also be applied to a cooling system that supplies a cooling liquid to a heat dissipation part of an ICT device.

  In the above-described embodiment, the ICT device 1 has been described as an example of the heat generating device. However, the present invention is not limited to this, and power supply such as a storage battery or an uninterruptible power supply for supplying power to the ICT device. It can also be applied to equipment.

Although the heat source device 7 according to the above-described embodiment is a water-cooled type including the cooling tower 7B, the present invention is not limited to this, and may be an air-cooled heat source device 7 (heat source unit 7A). Good.
The air conditioning system according to the above-described embodiment performs air conditioning of the server room in which the ICT equipment is installed. However, the present invention is not limited to this, and is applied to, for example, an air conditioning system for office buildings. Is possible.

  In the above-described embodiment, each control unit 10A to 10F is configured by a controller capable of autonomous control, and the integrated control device 10 is configured to control each control unit 10A to 10F in an integrated manner. Is not limited to this.

  That is, for example, the control units 10A to 10F and the integrated control device 10 may be used as one controller, and the entire air conditioning system (heat medium circulation system) may be controlled by the single integrated control device 10.

  In the above-described embodiment, the opening degree of the specific control valve 5Bs whose opening degree is changed by the power saving control mode and the limit opening degree are the same opening degree, but the present invention is not limited to this. The two openings may be different openings.

  In the above-described embodiment, the cold heat is generated by the vapor compressor type refrigerator, but the present invention is not limited to this. For example, when the waste heat can be sufficiently secured, the adsorption type refrigerator Or you may produce | generate cold with an absorption refrigerator.

  Further, the present invention is not limited to the above-described embodiment as long as it matches the gist of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 ... ICT apparatus 3 ... Rack 3A ... Cold wind passage 3C ... Duct space 3B ... Passage 5 ... Air-conditioning unit 5A ... Indoor heat exchanger 5B ... Flow control valve 5C ... Indoor fan 5Bs ... Specific control valve 7 ... Heat source device 7A ... Heat source machine 7B ... Cooling tower 7C ... Outdoor blower 7D ... Sprinkler 7E ... Outdoor heat exchanger 10 ... Integrated controller 10A ... Air conditioner controller 10B ... Secondary pump controller 10C ... Primary pump controller 10D ... Heat source controller 10E ... Cooling Water pump control unit 10F ... Cooling tower control unit P1 ... Primary pump P2 ... Secondary pump L1 ... Bypass flow path P3 ... Cooling water pump

Claims (16)

In a heat medium circulation system for circulating a heat medium that moves heat generated by a heat source device,
A plurality of heat exchangers for exchanging heat between the heat medium and the heat exchange object;
A pump device for circulating the heat medium;
A plurality of flow rate adjusting valves provided corresponding to the plurality of heat exchangers, wherein the flow rate adjusting valves adjust the amount of heat medium supplied to the heat exchanger;
While detecting the opening of the plurality of flow control valves, an opening detection unit that outputs an opening signal indicating the detected opening;
A control unit to which at least the opening signal is input, the control unit being capable of controlling the operation of the pump device and the opening of the flow rate adjustment valve in a power saving control mode,
The power saving control mode is:
An opening change in which the opening of at least one of the plurality of flow control valves (hereinafter, the flow control valve is referred to as a specific control valve) is made larger than before the power saving control mode is executed. function, and have a pump operation changing function of changing controlling the operation of the pump device on the basis of the opening degree variation of the specific control valve,
The control unit selects the specific control valve from among the plurality of flow rate adjustment valves, the flow rate adjustment valve having an opening less than a preset opening. . The control unit selects, as the specific control valve, a flow rate adjusting valve having the largest opening degree among the " flow rate regulating valves whose opening degree is less than a preset opening degree". 2. The heat medium circulation system according to 1. 3. The heat medium circulation system according to claim 1, wherein when the opening degree changing function is executed, the control unit sets the opening degree of the specific control valve to a predetermined opening degree or more. The controller does not execute the power saving control mode when the number of the flow rate adjusting valves whose opening is equal to or greater than a preset opening is equal to or greater than a preset limit number. The heat medium circulation system according to any one of claims 1 to 3 , wherein The heat medium circulation system according to claim 4 , wherein the control unit can change the limit number based on a cooling capacity required in the heat exchanger. The said control part can change the said "predetermined opening degree" based on the cooling capacity required by the said heat exchanger, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. Heat medium circulation system. A temperature detection unit that detects a temperature of a heat exchange target cooled by the heat exchanger and outputs a temperature signal indicating the detected temperature to the control unit,
The heat medium circulation system according to claim 5 or 6 , wherein the control unit calculates a cooling capacity required in the heat exchanger based on the temperature signal. A capacity adjusting device for adjusting a heat exchanging capacity generated in the heat exchanger;
A margin calculating unit that calculates a parameter (hereinafter referred to as “margin”) relating to a difference between the maximum heat exchange capability adjustable by the capability adjusting device and the actual heat exchange capability;
The control unit does not execute the power saving control mode when the margin related to any one of the plurality of heat exchangers is equal to or less than a preset warning threshold value. The heat medium circulation system according to any one of claims 1 to 7 . The heat medium circulation system according to any one of claims 1 to 8 , wherein the control unit executes the power saving control mode at predetermined intervals set in advance. The said control part reduces the discharge pressure of the said pump apparatus based on the opening degree change of the said specific control valve at the time of execution of the said pump operation change function, The one of Claim 1 thru | or 8 characterized by the above-mentioned. Described in the heat medium circulation system. The controller is configured to reduce the discharge pressure of the pump device stepwise within a predetermined change width based on a change in the opening of the specific control valve when the pump operation change function is executed. heating medium circulation system according to claim 1 0 of. The said control part reduces the rotation speed of the said pump apparatus based on the opening degree change of the said specific control valve at the time of execution of the said pump operation change function, The one of Claim 1 thru | or 8 characterized by the above-mentioned. Described in the heat medium circulation system. In a heat medium circulation system for circulating a heat medium that moves heat generated by a heat source device,
A plurality of heat exchangers for exchanging heat between the heat medium and the object;
A pump device for circulating the heat medium;
A plurality of flow rate adjusting valves provided corresponding to the plurality of heat exchangers, wherein the flow rate adjusting valves adjust the amount of heat medium supplied to the heat exchanger;
While detecting the opening of each of the plurality of flow control valves, an opening detection unit that outputs an opening signal indicating the detected opening;
And at least a control unit the position signal is input, the maximum opening degree of the plurality of values of total opening or an average degree of opening of flow control valve which is integrated or the plurality of flow rate adjusting valve in advance A control unit capable of controlling the operation of the pump device and the opening of the flow regulating valve so as to be equal to or more than a predetermined value ;
Provided for each of the heat exchangers, and a blower for blowing air blown into the room as the target ,
The heat exchanger corresponding to the blower in which the air volume is equal to or less than a predetermined air volume, and the opening degree of the flow rate adjustment valve that adjusts the amount of the heat medium supplied to the heat exchanger is predetermined. When the calculated opening is equal to or greater than the opening, the control unit excludes the opening of the flow rate adjustment valve from the calculation target when calculating the total opening or the average opening. Heating medium circulation system. The control unit determines an opening degree of the flow rate adjustment valve according to a heat exchange capability required in the heat exchanger, and a control mode for setting the opening degree of the flow rate adjustment valve to the determined opening degree. heat medium circulation system according to any one of claims 1 to 1 3, characterized in that it is feasible. During execution of the power saving control mode, the control unit controls the operation of the pump device so that the pressure at a part separated from the discharge unit of the pump device by a predetermined dimension or more is equal to or higher than a preset pressure. heating medium circulation system according to any one of claims 1 to 1 4, characterized in that. A heat source device for generating cold heat;
A plurality of heat exchangers that exhibit cooling capacity by the heat medium cooled by the cold, and
A pump device for circulating the heat medium;
A plurality of flow rate adjustment valves provided corresponding to each of the plurality of heat exchangers, a plurality of flow rate adjustment valves for adjusting the amount of heat medium supplied to the heat exchanger;
While detecting the opening of each of the plurality of flow control valves, an opening detection unit that outputs an opening signal indicating the detected opening;
A control unit to which at least the opening signal is inputted, and a control unit configured by a computer capable of controlling the operation of the pump device and the opening of the flow rate adjustment valve in a power saving control mode. A program used for a medium circulation system,
When executing the power saving control mode, the control unit,
An opening change in which the opening of at least one of the plurality of flow control valves (hereinafter, the flow control valve is referred to as a specific control valve) is made larger than before the power saving control mode is executed. Function, and act as a pump operation change function to change and control the operation of the pump device based on the opening change of the specific control valve ,
Furthermore, in the opening degree change function, the specific control valve is selected from among the plurality of flow rate adjustment valves, the flow rate adjustment valve having an opening degree less than a preset opening degree. Program for circulating heat medium.