JP4523461B2 - Operation control method for 1-pump heat source equipment - Google Patents

Description

  The present invention relates to an operation control method in a one-pump heat source facility used as a heat source supply system such as a district cooling and heating facility or a heat source supply system such as a factory or a building.

  2. Description of the Related Art Conventionally, a one-pump heat source facility has been known as a heat source facility used as a heat source supply system such as a district air conditioning facility or a heat source supply system such as a factory or a building.

  As shown in FIG. 4, the one-pump heat source equipment includes first to third heat source devices 51 </ b> A to 51 </ b> C that heat or cool a heat medium, and a heat medium heated or cooled by each of the heat source devices 51 </ b> A to 51 </ b> C. The heat medium pumps 52A to 52C for pressure feeding, the feed header 54 for collecting the heat medium pumped by the heat medium pumps 52A to 52C, and the heat exchangers (air conditioners) 58 disposed in each part (room), The return header 50 distributes the heat medium returned from the heat exchangers (air conditioners) 58, 58,... To the heat source devices 51A to 51C, and the feed header 54 and the return header 50. , A bypass valve 63 provided in the middle thereof, and a control device 60 that controls the heat source devices 51A to 51C and controls the opening degree of the bypass valve 63.

  In such a heat source facility, the heat medium pumped by the heat medium pumps 52A to 52C is cooled or heated by the heat source devices 51A to 51C, mixed in the feed header 54, and heat exchanger (air conditioner) via the outgoing water pipe. ) 58, 58. Then, after heat exchange in the heat exchangers (air conditioners) 58, 58..., The heat is returned to the return header 50 through the return water pipe, and is again pumped and circulated by the heat medium pumps 52A to 52C (Patent Document 1 below). -3 etc.)

  In the increase / decrease stage control of the heat source devices 51A to 51C by the control device 60, for example, as shown in FIG. 5, the number control based on the circulation flow rate Q, the heat source inlet temperature TI, and the water supply temperature TS is performed.

  Here, in FIG. 5, the heat source device step-down temperature setting value TIS that is the step-down condition of the heat source device is calculated from the following equation (2). In addition, the heat source equipment step-up temperature set value TSS is set to a fixed value (usually 8 ° C) throughout the year, the lower limit flow rate is the refrigerator rated flow rate x (number of units -1), and the upper limit flow rate is the refrigerator rated flow rate. × Number of operating units.

JP 2000-18683 A JP 2004-184052 A JP 2004-245560 A

  However, in the one-pump system heat source facility, the heat medium pumps 52A to 52C are operated at their ratings and the discharge pressure is kept constant, so that the flow rate in the heat source devices 51A to 51C is secured and destabilized (hunting, etc.) Therefore, there is a problem that the pump power cannot be reduced even at a small load.

  On the other hand, regarding the increase / decrease stage control of the heat source equipment, in the one-pump heat source equipment, the heat source equipment 51A to 51C exhibits its maximum capacity when there is a predetermined heat medium temperature difference (9 ° C. in the above example). In practice, however, a phenomenon occurs in which the temperature difference between the return and return of water decreases, especially at a small load. This drop in the return temperature difference is due to excessive cold water flowing into the heat exchanger 58 due to excessive opening of the valve or excessive pressure, insufficient air flow through the heat exchanger 58, heat exchange, etc. May occur when the heat exchanger is deteriorated, or may be caused by the provision of a terminal bypass (not shown) that bypasses the heat exchanger 58, for example. When the temperature difference between the return and return of the heat medium is reduced, the heat medium pumps 52A to 52C are operating at a rated operation, but the heat source devices 51A to 51C are in a state of operating with their own cooling capacity reduced. In this state, when the amount of heat required by the heat exchanger 58 increases, the number of steps to the second and third heat source devices 51B and 51C is increased even though the first heat source device 51A is in a throttle operation. It was supposed to be done. That is, before each heat source device 51A exhibits its maximum capacity, unnecessary stages are added to the second and third heat source devices 51B and 51C, and an uneconomic operation is performed.

  On the other hand, for the step-down control, the heat source device step-down temperature setting value TIS for each operating unit is T = 2 = TIS = 9.5 ° C., n = 3 under the conditions of TOS = 7 ° C. and TRS = 12 ° C .: TIS = 10.3 ° C, n = 4 units: TIS = 10.75 ° C, and as the number of operating units increases, the temperature difference of the heat source equipment step-down temperature setting value TIS becomes extremely small. The heat source inlet temperature TI is difficult to measure with high accuracy, and the chilled water return temperature (TRS) is an assumed value, and since it always changes in practice, there is a problem that the judgment of decrease in the number of operating units cannot be made accurately. It was.

  Therefore, the main problem of the present invention is to operate in a one-pump heat source facility in which power is reduced even in an inefficient operating state at a small load, and power is reduced by eliminating inefficient step-up control. It is to provide a control method.

In order to solve the above-mentioned problem, as the present invention according to claim 1, a plurality of heat source devices for cooling or heating the heat medium, and a heat medium that is provided corresponding to each heat source device and pumps the cooled or heated heat medium. A heat medium pump, a feed header that collects the heat medium from the heat source device, an external load device that is supplied with the heat medium from the feed header, and a heat medium that is heat-exchanged by the external load device are returned, A return header distributed to the heat source device, a bypass and bypass valve connecting the feed header portion or the vicinity thereof and the return header portion or the vicinity thereof, operation number control of the heat source device and operation control of the heat medium pump are performed. In a one-pump heat source facility comprising a control device,
A flow meter for measuring the circulating flow rate Q of the heat medium, a forward water thermometer for measuring the outgoing water temperature TS, an outlet thermometer for measuring the outlet temperature TO of the heat source device, and the heat source device A power meter for measuring the input value W, a steam flow meter or a gas flow meter, and a means for detecting the number of operating heat medium pumps;
The control device has, in advance, a set value table for each operating state of Normal, high, and low as the heat source outlet temperature setting value TOS and the heat source step-up temperature setting value TSS for each period divided based on the load state. The heat source outlet temperature set value TOS and the heat source step increase temperature set value TSS are set and changed based on the circulating flow rate Q of the heat medium and the number of heat medium pumps operated. Decrease the number of operating heat source devices based on the comparison between the circulation flow rate Q and the heat source device rated flow x the upper limit flow rate expressed by the number of units in operation and the comparison between the outgoing water temperature TS and the heat source stage temperature setting value TSS. Stage control is a comparison between the circulation rate Q of the heat medium and the lower limit flow rate expressed by the heat source equipment rated flow x (number of operating units -1), and the input value W to the heat source equipment and the preset heat source equipment reduction input setting. and performing, based on a comparison between the value WS Operation control method in the pump system heat source equipment is provided.

  In the first aspect of the present invention, the heat source equipment outlet temperature set value TOS, which is a fixed value in the conventional heat source equipment, is variably set for each period, and the heat source stage temperature setting which is a part of the stage increase condition is set. The value TSS is also variably set for each period.

  First, by variably setting the heat source equipment outlet temperature set value TOS for each period, equipment efficiency (COP) can be improved and power consumption can be reduced. In other words, when the circulation flow rate Q is small, if the heat source outlet temperature TO rises, the pump power increases due to the increase in the circulation flow rate. This increase is due to the decrease in the heat source device power due to the improvement in the equipment efficiency (COP) of the heat source equipment. Therefore, when considering the entire system including the heat source device and the pump, the power consumption decreases by increasing the outlet temperature TO.

Furthermore, regarding the step-down control, since it is possible to determine the appropriate reduction in the number of operating units by setting the step-down condition of the heat source device to the heat source device input value W, it is possible to prevent an unnecessary heat source device from being operated.
As the present invention according to claim 2, the change control of the heat source outlet temperature set value TOS and the heat source additional stage temperature set value TSS includes the circulation flow rate Q, the power reduction amount of the heat source device due to the heat source outlet temperature rise, and the pump power increase amount. Compared with the circulation flow rate setting value Qh that is balanced, the number of operating heat pumps, and the circulation flow rate Q, and the heat source equipment power decrease when the heat source outlet temperature setting value TOS is changed from Normal to Low, and the pump power increase The operation control method for a one-pump heat source facility according to claim 1, wherein the operation control method is performed by comparison with a circulating flow rate set value QI that balances the minute.

According to a third aspect of the present invention, there is provided the operation control method for a one-pump heat source facility according to any one of the first and second aspects, wherein the heat source equipment step-down input set value WS is obtained by the following equation (1). .

  As described above in detail, according to the present invention, even in an inefficient operation state at a small load, the power source outlet temperature set value TOS is increased to reduce power by increasing the heat source equipment efficiency. Further, the increase control of the number of operating heat source devices is performed based on the circulation flow rate Q and the outgoing water temperature TS, and the decrease control of the operation number of the heat source devices is performed based on the circulation flow rate Q of the heat medium and the input value W to the heat source device. By performing based on the above, it is possible to prevent the number of operating units from being increased even though the heat source device is performing the throttle operation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[Configuration of 1-pump heat source equipment]
A one-pump heat source facility 1 shown in FIG. 1 is provided corresponding to a plurality of heat source devices 2A to 2C for cooling or heating a heat medium and each of the heat source devices 2A to 2C, and a heat medium that pumps the heat medium. The pumps 3A to 3C, the feed header 4 that collects the heat medium from the heat source devices 2A to 2C, the external load devices 9, 9 ... such as an air conditioner to which the heat medium is supplied from the feed header 4, and the external load device The heat medium exchanged by 9, 9... Is returned, and the return header 10 distributed to each of the heat source devices 2A to 2C is connected to the feed header portion 4 or the vicinity thereof and the return header portion 10 or the vicinity thereof. It comprises a bypass 13 and a bypass valve 12 and a control device 8 that controls the operation number of the heat source devices 2A to 2C and the operation control of the heat medium pumps 3A to 3C.

As measuring instruments, a flow meter 14 for measuring the circulating flow rate of the heating medium, a return water thermometer 15 for measuring the return water temperature TR, and a forward water thermometer for measuring the outgoing water temperature TS. 20, a thermometer 16 for measuring the inlet temperature TI of the heat source device, a thermometer 18 for measuring the outlet temperature TO of the heat source device, and a wattmeter for measuring an input value W to the heat source devices 2A to 2C A steam flow meter or a gas flow meter (not shown) and an operating number detection means (not shown) of the heat medium pumps 3A to 3C are arranged.
[Operation control by the control device 8]
The control device 8 sets, as the heat source outlet temperature set value TOS and the heat source step-up temperature set value TSS in advance, a set numerical value table for each of the normal, high, and low operating states for each period divided based on the load state. The heat source outlet temperature set value TOS and heat source booster temperature set value TSS are set and changed based on the circulating flow rate Q of the heat medium and the number of operating heat pumps. Q is based on the comparison of the rated flow rate of heat source equipment x the upper limit flow rate expressed by the number of units in operation and the comparison of the incoming water temperature TS and the heat source stage temperature setting value TSS. For comparison of the flow rate Q and the lower limit flow rate expressed by the heat source device rated flow rate x (number of operating units -1), and the comparison between the input value W to the heat source device and the heat source device stepped input setting value WS set in advance. It is to be performed based on.
[Setting of heat source outlet temperature setting value TOS and heat source additional temperature setting value TSS]
More specifically, the setting numerical value table of the heat source outlet temperature setting value TOS and the heat source additional temperature setting value TSS is based on the past results, etc., and the setting value of the heat source outlet temperature setting value TOS and the heat source additional temperature setting value TSS Are determined according to the operation state of Normal, high, and low, for example, every month or season. As shown in Table 1, this set numerical value table is generally determined so that the temperature difference between the heat source outlet temperature set value TOS and the heat source additional stage temperature set value TSS is 1 ° C. In addition, the setting numerical value table is determined for the month or the season, but may be classified according to any index as long as the operation state of the heat source device is classified according to the load situation (operating situation). .

  The control device 8 sets and changes the heat source outlet temperature set value TOS and the heat source step-up temperature set value TSS based on the circulating flow rate Q of the heat medium and the number of operating heat medium pumps. Here, the heat source outlet temperature setting value TOS is set to the outlet temperature setting value TO of the heat source devices 2A to 2C, which has been conventionally fixed, and the outlet temperature of the heat medium is relatively increased throughout the year at low load periods. The power consumption is reduced by improving the heat source efficiency of the heat source devices 2A to 2C.

  Specifically, as shown in the flowchart of FIG. 2, at the start of operation of the heat source facility 1, first, the heat source outlet temperature set value and the stage increasing condition normal corresponding to the time are read and set in the control device 8. (Step-1).

  Next, the circulation flow rate Q measured by the flow meter F is compared with a preset circulation flow rate setting value Qh (hereinafter also referred to as an upper limit flow rate setting value). When Q ≧ Qh, the heat source equipment outlet temperature is compared. Change the set value TOS and the heat source equipment step-up temperature set value TSS to the step-up condition High (Step-2). Here, the upper limit flow rate setting value Qh is a circulating flow rate that balances the power reduction amount of the heat source devices 2A to 2C due to the rise of the heat source outlet temperature TO and the pump power increase amount.

  For example, the Qh calculation example when the heat source devices 2A to 2C are air-cooled chillers is shown below.

  The air-cooled chiller power Eref is obtained from the following equation (3).

  On the other hand, the pump power Epom can be obtained from the following equation (5).

  The circulation flow rate Q is obtained from the following equation (6).

  The following equation (7) is established from the condition that the increase in heat source device power and the decrease in pump power when the heat source device outlet temperature set value TOS is changed from Normal to High.

  From the above equations (3) and (5) to (7), the following equation (8) is established.

  The load factor q is obtained from the above equation (8), and the upper limit flow rate setting value Qh is calculated from the above equation (6). Note that other heat source devices can be calculated based on the same concept.

  In Step-2 above, when Q <Qh, if the number of operating heat medium pumps 3A to 3C is two or more, increase the heat source equipment outlet temperature set value TOS and the heat source equipment increased temperature set value TSS. The condition Normal is maintained (Step-3). Further, when the circulating flow rate Q is equal to or lower than the lower limit flow rate setting value QI of the circulating flow rate, the heat source device outlet temperature setting value TOS and the heat source device increasing temperature setting value TSS are changed to the increasing condition Low (Step-4). The lower limit flow set value QI of the circulating flow can be calculated by the same calculation procedure as the upper limit flow set value Qh.

In addition, if there is a change in conditions, a waiting time is set for the timer setting time until it stabilizes, the heat source equipment outlet temperature setting value TOS is used for heat source equipment capacity control, and the heat source equipment additional temperature setting value is used for heat source number control. Send TSS.
[Increase / decrease control of heat source equipment]
Regarding the increase / decrease stage control of the heat source devices 2A to 2C, as shown in FIG. 3, the increase in the number of operating heat source devices is a comparison between the circulation flow rate Q and the upper limit flow rate represented by the heat source device rated flow × the number of operating units. And the lowering of the number of operating heat source devices is the lower limit expressed by the circulation flow rate Q and the heat source device rated flow x (number of operating units -1). The comparison is made based on the comparison with the flow rate and the comparison between the input value W (electric power, steam or gas measurement value) to the heat source device and the heat source device step-down input set value WS set in advance.

  At this time, the heat source equipment stage reduction input set value WS, which is the stage reduction condition, is calculated by the following equation (1).

  As described above, the circulation flow rate Q is equal to or less than the lower limit value represented by the heat source device rated flow rate × (number of operating units−1), and the input value W is equal to or less than the heat source device reduction step input set value WS. By doing so, it is possible to accurately determine the number of units to be operated in response to changes in capacity due to heat source equipment outlet water temperature set value TOS, outside air temperature, and aging degradation. Incidentally, when the heat source equipment step-down input setting value WS for each of the above-mentioned operating units is a = 1.0, b = 1.0, C = 0.0, n = 2 units: WS = 50%, n = 3 units: WS = 67 %, N = 4 units: WS = 75% and the difference between the set values is large, so the power consumption or current value, steam volume, and gas volume to be measured can be measured with high accuracy, so it is possible to accurately determine the number of units to be operated. Will be made.

  Further, the stage increase condition is that the circulation flow rate Q exceeds the upper limit value represented by the heat source equipment rated flow rate x the number of units in operation and the water temperature TS exceeds the heat source equipment step increase temperature setting value TSS. It is possible to prevent the number of operating units from being increased even though the heat source devices 2A to 2C are performing the throttle operation.

1 is a block diagram showing a one-pump heat source facility 1 according to the present invention. It is a flowchart which shows the setting / change method of the heat source exit temperature setting value TOS and the heat source stage temperature setting value TSS. It is a flowchart which shows the increase / decrease stage control of a heat source apparatus. It is a block diagram which shows the conventional 1 pump system heat source installation. It is a flowchart which shows the increase / decrease stage control of the conventional heat source apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... 1 pump system heat source equipment, 2A-2C ... Heat source apparatus, 3A-3C ... Heat medium pump, 4 ... Feed header, 8 ... Control apparatus, 9 ... External load apparatus, 10 ... Return header, 12 ... Bypass valve, 13 ... Bypass, 14 ... Flow meter, 15, 16, 20 ... Thermometer, 17 ... Differential pressure gauge

Claims (3)

A plurality of heat source devices that cool or heat the heat medium, a heat medium pump that is provided corresponding to each heat source device and that pumps the cooled or heated heat medium, and a feed that collects the heat medium from the heat source device A header, an external load device to which a heat medium is supplied from the feed header, a return header to which the heat medium exchanged by the external load device is returned and distributed to each heat source device, and the feed header section or the vicinity thereof 1-pump heat source equipment comprising a bypass and a bypass valve connecting the return header part or the vicinity thereof, and a control device for controlling the number of operating heat source devices and operating the heat medium pump,
A flow meter for measuring the circulating flow rate Q of the heat medium, a forward water thermometer for measuring the outgoing water temperature TS, an outlet thermometer for measuring the outlet temperature TO of the heat source device, and the heat source device A power meter for measuring the input value W, a steam flow meter or a gas flow meter, and a means for detecting the number of operating heat medium pumps;
The control device has, in advance, a set value table for each operating state of Normal, high, and low as the heat source outlet temperature setting value TOS and the heat source step-up temperature setting value TSS for each period divided based on the load state. The heat source outlet temperature set value TOS and the heat source step increase temperature set value TSS are set and changed based on the circulating flow rate Q of the heat medium and the number of heat medium pumps operated. Decrease the number of operating heat source devices based on the comparison between the circulation flow rate Q and the heat source device rated flow x the upper limit flow rate expressed by the number of units in operation and the comparison between the outgoing water temperature TS and the heat source stage temperature setting value TSS. Stage control is a comparison between the circulation rate Q of the heat medium and the lower limit flow rate expressed by the heat source equipment rated flow x (number of operating units -1), and the input value W to the heat source equipment and the preset heat source equipment reduction input setting. and performing, based on a comparison between the value WS Operation control method in the pump system heat source facilities.   The change control of the heat source outlet temperature set value TOS and the heat source outlet temperature set value TSS includes the circulation flow rate Q and the circulation flow rate set value Qh that balances the power reduction amount of the heat source device due to the heat source outlet temperature rise and the pump power increase amount. Comparison, heat medium pump operation number, circulation flow rate Q, and heat flow rate setting value QI that balances the decrease in heat source equipment power and the increase in pump power when heat source outlet temperature setting value TOS is changed from Normal to Low The operation control method in the 1 pump type heat source equipment of Claim 1 performed by comparison with. The operation control method for a one-pump heat source facility according to any one of claims 1 and 2, wherein the heat source device reduction stage input set value WS is obtained by the following equation (1).

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