WO2016024505A1

WO2016024505A1 - Load distribution system

Info

Publication number: WO2016024505A1
Application number: PCT/JP2015/072204
Authority: WO
Inventors: 瑞樹田中
Original assignee: ダイキン工業株式会社
Priority date: 2014-08-11
Filing date: 2015-08-05
Publication date: 2016-02-18
Also published as: JP2016038189A

Abstract

In the present invention, a load distribution system is provided with a first refrigerator (51), a second refrigerator (52) arranged in parallel with the first refrigerator (51), a first pump (61) able to modify the volume of discharge of a heat medium, a second pump (62) that has a constant volume of discharge of the heat medium per unit time, secondary-side equipment (20), and a refrigerator number determination unit (182). If there is a gradual increase in a load that is demanded by the secondary-side equipment (20) and a demand is made for a load greater than or equal to a load that can be handled with the first refrigerator (51), which is a heat source machine that has a variable-speed compressor, then the refrigerator number determination unit (182) initiates driving of the second pump (62) so that the heat medium flows to the second refrigerator (52), which is a heat source machine that has a constant-speed compressor or is an endothermic-type heat source machine, and also controls driving of the first pump (61) so that the flow rate of the heat medium to the first refrigerator (51) is less than the flow rate of the heat medium to the second refrigerator (52).

Description

Load distribution system

The present invention relates to a load distribution system.

Conventionally, a heat source device having a variable speed compressor and a heat source device having a constant speed compressor or an absorption heat source device are arranged in parallel, and each heat source device is driven according to a load required from the use side equipment. There is a system to control. Here, it is known that the operation efficiency when the heat source machine or the absorption heat source machine having the constant speed compressor is driven with the rated capacity is much better than the heat source machine having the variable speed compressor. On the other hand, at the time of partial load, the operation efficiency of the heat source machine or the absorption heat source machine having the constant speed compressor is lower than that of the heat source machine having the variable speed compressor because the operation efficiency is lowered. For this reason, when using each heat source machine in combination, the conventional technology of improving the energy efficiency of the entire system by changing the load distribution of each heat source machine according to the load required from the user side equipment There is.

By the way, the load of each heat source machine has the property of being proportional to the supply amount of the heat medium to each heat source machine. In addition, a lower limit flow rate, which is the minimum flow rate of the heat medium required for operation, is set in the heat source unit in order to prevent an abnormal stop due to freezing or the like. For this reason, even when adjusting the supply amount of the heat medium to each heat source unit and changing the load distribution of each heat source unit, the heat medium is supplied to each heat source unit so that it does not fall below the lower limit flow rate. There is a problem that must be.

In order to solve this problem, in the system described in Patent Document 1 (Japanese Patent Laid-Open No. 2010-127559), in a heat medium circuit configured by sequentially connecting a plurality of pumps, a plurality of heat source units, and a use-side facility. A bypass pipe for returning the heat medium after passing through the heat source unit to the upstream side of the pump is provided. In this system, by changing the flow rate of the heat medium flowing through the bypass pipe, it is possible to set the load distribution to each heat source unit without considering the lower limit flow rate of the heat source unit.

However, in the system described in Patent Document 1, an inverter pump that can change the discharge capacity of the heat medium is regarded as an essential component. Those skilled in the art who have seen such prior art think that it is necessary to use all of the pumps that flow the heat medium to each heat source machine as inverter pumps, and give up realizing the optimum efficiency due to cost constraints. May end up.

Therefore, an object of the present invention is to provide a load distribution system capable of suppressing an increase in cost and appropriately setting load distribution to each heat source unit.

The load distribution system concerning the 1st viewpoint of the present invention is provided with the 1st heat source machine, the 2nd heat source machine, the 1st pump, the 2nd pump, the use side equipment, and the control part. The first heat source machine heats or cools the heat medium. The second heat source machine heats or cools the heat medium. The 2nd heat source machine is arranged in parallel with the 1st heat source machine. The first pump causes the heat medium to flow to the first heat source machine. The first pump can change the discharge capacity of the heat medium. The second pump causes the heat medium to flow to the second heat source machine. The second pump has a constant heat medium discharge capacity per unit time. The use side facility is supplied with a heat medium from the first heat source device and the second heat source device. A control part controls the drive number of a 1st heat-source machine and a 2nd heat-source machine according to the load requested | required from a utilization side installation. The first heat source machine is a heat source machine having a variable speed compressor. The second heat source machine is a heat source machine having a constant speed compressor or an endothermic heat source machine. When the load required from the use side equipment is gradually increased and a load higher than the load that can be handled by the first heat source machine is requested, the control unit causes the heat medium to flow to the second heat source machine. The driving of the second pump is started, and the driving of the first pump is controlled so that the flow rate of the heat medium for the first heat source device is smaller than the flow rate of the heat medium for the second heat source device.

Here, as a result of intensive studies, the present inventors have determined that each heat source machine is a system in which a heat source machine having a variable speed compressor and a heat source machine having a constant speed compressor or an endothermic heat source machine are arranged in parallel. When using in combination, the discharge capacity per unit time is constant even if a heat medium is flowed by a pump whose discharge capacity can be changed with respect to a heat source machine having a constant speed compressor or an endothermic heat source machine. It was found that even when the heat medium is flowed by the pump of No. 1, there is almost no difference in the flow rate of the heat medium flowing through the heat source machine having the constant speed compressor or the endothermic heat source machine due to the pressure with other pumps.

In the load distribution system according to the first aspect of the present invention, the heat medium flows to the second heat source machine that is a heat source machine having a constant speed compressor or an endothermic heat source machine by a pump having a constant discharge capacity per unit time. It is a configuration. For this reason, an amount of heat medium equivalent to that in the case where the heat medium flows through the second heat source device by the pump whose discharge capacity can be changed can be flowed through the second heat source device. Furthermore, since a pump having a constant discharge capacity per unit time is generally cheaper than a pump capable of changing the discharge capacity, the heat medium is transferred to the second heat source machine by a pump capable of changing the discharge capacity. The cost can be reduced compared to the case where the current flows.

This makes it possible to suppress an increase in cost and appropriately set the load distribution for each heat source device.

The load distribution system according to the second aspect of the present invention is the load distribution system according to the first aspect, wherein there are two or more first heat source units. The total capacity of the first heat source machine is equal to or less than the rated capacity of the second heat source machine. For this reason, when it comes to the situation where the 2nd heat source machine is driven in addition to the 1st heat source machine, the energy loss of the whole system can be suppressed by adjusting the flow rate of the heat medium to each first heat source machine. .

A load distribution system according to a third aspect of the present invention includes the heat medium circulation circuit in the load distribution system according to the first aspect or the second aspect. The heat medium circuit includes a forward header, a return header, a first path, and a bypass path. The forward header mixes the heat medium flowing out from the first heat source machine and the second heat source machine. In the return header, the heat medium that has been heat-exchanged in the user-side equipment flows back. A 1st path | route is a path | route which flows the heat medium of a return header to a forward header via a 1st pump and a 1st heat source machine. The bypass path is provided in the first path. The bypass path returns the heat medium after passing through the first heat source device to the upstream side of the first pump. In this load distribution system, the heat medium after passing through the first heat source device by the bypass path can be returned to the upstream side of the first pump.

In the load distribution system according to the first aspect of the present invention, it is possible to suppress an increase in cost and appropriately set load distribution to each heat source unit.

In the load distribution system according to the second aspect of the present invention, energy loss of the entire system can be suppressed.

In the load distribution system according to the third aspect of the present invention, the heat medium after passing through the first heat source device can be returned to the upstream side of the first pump.

1 is a schematic configuration diagram of a load distribution system according to an embodiment of the present invention. The control block diagram of the control apparatus with which a load distribution system is provided. The figure which shows the flow of the refrigerator number control by a chiller system controller. The schematic block diagram of the primary side equipment with which the load distribution system as a prior art is provided. The figure for demonstrating each energy loss of the load distribution system which concerns on this embodiment, and the load distribution system as a prior art. The schematic block diagram of the primary side equipment with which the load distribution system which concerns on the modification A is provided. The figure for demonstrating each energy loss of the load distribution system which concerns on the modification A, and the load distribution system as a prior art. The schematic block diagram of the primary side equipment with which the load distribution system which concerns on the modification B is provided. The figure for demonstrating each energy loss of the load distribution system which concerns on the modification B, and the load distribution system as a prior art.

Hereinafter, a load distribution system according to an embodiment of the present invention will be described with reference to the drawings. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention.

(1) Overall Configuration of Load Distribution System FIG. 1 is a schematic configuration diagram of a load distribution system according to an embodiment of the present invention. The load distribution system according to the present embodiment can suppress deterioration in energy efficiency of the entire system. Load distribution systems are mainly installed in relatively large buildings such as buildings, factories, hospitals, and hotels.

As shown in FIG. 1, the load distribution system includes a heating medium between a primary side equipment 10 as a heat source side equipment and a secondary side equipment 20 as a usage side equipment via a pipe connecting the both 10 and 20. As a system to circulate water.

The primary side equipment 10 mainly includes first to third refrigerators 51 to 53 as heat source units for heating or cooling a heat medium, and first to third refrigerators 51 to 53 provided corresponding to the first to third refrigerators 51 to 53. Third pumps 61 to 63.

In addition, the 1st refrigerator 51 of this embodiment is a heat source machine which has a variable speed compressor. The variable speed compressor is a compressor capable of changing the rotation speed. The first refrigerator 51 is a variable capacity type heat source device that can be operated by adjusting the capacity (refrigeration capacity) by switching the rotation speed of the compressor. The 2nd refrigerator 52 and the 3rd refrigerator 53 are heat source machines which have a constant speed compressor. A constant speed compressor is a compressor in which the rotational speed of the compressor is constant. By the way, in this embodiment, although the 2nd refrigerator 52 and the 3rd refrigerator 53 are heat source machines which have a constant speed compressor, the 2nd refrigerator 52 and the 3rd refrigerator 53 are absorption type heat source machines. May be. The absorption heat source machine is a heat source machine that does not include a compressor and has a constant capacity. That is, the 2nd freezer 52 and the 3rd freezer 53 are constant capacity type heat source machines.

In this embodiment, the variable capacity heat source unit is supplied with water from a pump whose discharge capacity can be changed, and the constant capacity type heat source unit is supplied with a pump having a constant discharge capacity per unit time. Water shall be supplied.

The secondary-side equipment 20 mainly includes first to ninth air conditioners 21 to 29 which are heat utilization devices installed in each air-conditioning target space (hereinafter referred to as indoor space) in the building. Then, cold water flows during cooling, warm water flows from the primary side equipment 10 to the secondary side equipment 20 during heating, and the first to ninth air conditioners 21 to 29 during operation of the secondary side equipment 20 are cooled or heated. Used for air conditioning.

The primary side equipment 10 is controlled by a chiller system controller 110, and the secondary side equipment 20 is controlled by an air conditioner controller 120.

(2) Detailed configuration of load distribution system (2-1) Heat medium circulation circuit 70
The heat medium circulation circuit 70 is a closed circuit filled with water, and is configured so that water circulates between the first to third refrigerators 51 to 53 and the first to ninth air conditioners 21 to 29. ing. The heat medium circulation circuit 70 includes first to third pumps 61 to 63, first to third refrigerators 51 to 53, a forward header 11, first to ninth air conditioners 21 to 29, and a return header. 12 are connected.

As shown in FIG. 1, the heat medium circulation circuit 70 includes a secondary side pipe 71, a first common pipe 72, a second common pipe 73, first to third pipes 74 to 76, a bypass pipe 77, Have. The secondary side pipe 71 connects the forward header 11 and the return header 12 so that water flows through the first to ninth air conditioners 21 to 29, respectively. The first common pipe 72 is connected to the return header 12. The second common pipe 73 is connected to the forward header 11. The first to third pipes 74 to 76 are pipes that connect the first common pipe 72 and the second common pipe 73. More specifically, the first to third pipes 74 to 76 are arranged in parallel so as to connect the branch point P1 located at the end of the first common pipe 72 and the branch point P2 located at the end of the second common pipe 73. It is the piping provided in. The bypass pipe 77 connects the return header 12 and the forward header 11.

(2-2) Primary equipment 10
In the primary side equipment 10, the three first to third refrigerators 51 to 53 serve as heat sources in the load distribution system. Each of the first to third refrigerators 51 to 53 is provided with one each of the first to third pumps 61 to 63. The first to third refrigerators 51 to 53 are connected in parallel to each other as shown in FIG. Specifically, the first pipe 74 is provided with the first pump 61 and the first refrigerator 51, the second pipe 75 is provided with the second pump 62 and the second refrigerator 52, and the third pipe 76 is provided with A third pump 63 and a third refrigerator 53 are provided.

The first to third refrigerators 51 to 53 are air-cooled heat pump chillers, and a compressor, an air side heat exchanger, an expansion valve, and a water side heat exchanger are sequentially connected to form a refrigerant circuit. Is filled with a refrigerant. As described above, the first refrigerator 51 is equipped with one or a plurality of variable speed compressors, and in this embodiment, the variable speed compressor is an inverter compressor whose capacity can be adjusted. As described above, the second and third refrigerators 53 are equipped with one or a plurality of constant speed compressors. In this embodiment, the constant speed compressors are compressors whose capacity cannot be adjusted. Instead of the constant speed compressor of this embodiment, a compressor whose capacity can be adjusted by hot gas bypass may be used.

The first to third pumps 61 to 63 are for flowing water to the first to third refrigerators 51 to 53, respectively, and play a role of circulating water in the heat medium circulation circuit 70. The first pump 61 causes water to flow to the first refrigerator 51. The first pump 61 is a pump capable of changing the discharge capacity, that is, a variable capacity pump, and is inverter-driven by the chiller system controller 110. For this reason, the first pump 61 can adjust the amount of water flowing to the first refrigerator 51 when flowing water to the first refrigerator 51. The second pump 62 causes water to flow to the second refrigerator 52. The second pump 62 is a constant speed pump in which the discharge amount of water per unit time is constant, and its start / stop is controlled by the chiller system controller 110. For this reason, the second pump 62 cannot adjust the amount of water flowing to the second refrigerator 52 when flowing water to the second refrigerator 52. The third pump 63 causes water to flow to the third refrigerator 53. The third pump 63 is a constant speed pump in which the discharge amount of water per unit time is constant, and its start / stop is controlled by the chiller system controller 110. For this reason, the third pump 63 cannot adjust the amount of water flowing to the third refrigerator 53 when flowing water to the third refrigerator 53.

In the primary side equipment 10, the first to third pumps 61 to 63 are driven, so that water (cold water or hot water) sent from the first to third refrigerators 51 to 53 is sent to the second common pipe 73 and the outgoing pipe. It flows to the secondary side pipe 71 through the header 11. In addition, the water returned from the secondary equipment 20 through the secondary pipe 71 flows into the return header 12 and then passes through the first common pipe 72 to the first to third refrigerators 51 to 53. Flowing.

Further, a bypass flow rate adjusting valve 77a is provided in the bypass pipe 13 connecting the forward header 11 and the return header 12. By changing the opening of the bypass flow rate control valve 77a and adjusting the flow rate of water that returns directly from the forward header 11 to the return header 12 through the bypass pipe 13, the flow rate of water flowing to the secondary equipment 20 is suppressed. be able to.

(2-3) Secondary equipment 20
The secondary side equipment 20 has nine first to ninth air conditioners 21 to 29 as heat utilization devices. The first to ninth air conditioners 21 to 29 use the cold water of the cold water or the hot water generated by the first to third refrigerators 51 to 53 of the primary side equipment 10 that is a heat source unit, respectively, Handle the load. In other words, the first to ninth air conditioners 21 to 29 perform air conditioning (cooling or heating) of the indoor space using cold water or hot water flowing from the primary side equipment 10.

The first to ninth air conditioners 21 to 29 are installed in the same or different indoor spaces. Each of the first to ninth air conditioners 21 to 29 is arranged in parallel between the secondary side pipe 71 extending from the forward header 11 and the secondary side pipe 71 connected to the return header 12. The first to ninth air conditioners 21 to 29 take in water from the secondary pipe 71 on the forward header 11 side and return the water to the secondary pipe 71 on the return header 12 side.

In each casing of the first to ninth air conditioners 21 to 29, an air passage through which air flows is formed. One end of a suction duct (not shown) is connected to the inflow end of the air passage, and one end of an air supply duct (not shown) is connected to the outflow end of the air passage. The other ends of the suction duct and the air supply duct are each connected to the indoor space.

In each casing of the first to ninth air conditioners 21 to 29, a blower fan, a heat exchanger, a flow rate adjusting valve, and the like are arranged. The heat exchanger causes heat exchange between water and air to cool or heat the air. As the heat exchanger, for example, a fin-and-tube heat exchanger having a plurality of heat transfer fins and a heat transfer tube penetrating the heat transfer fins is employed. In the heat transfer tube of the heat exchanger, water circulating between the primary side equipment 10 and the secondary side equipment 20 flows, and the heat of the water is supplied to the air via the heat transfer pipe and the heat transfer fins. The air is cooled or heated. The blower fan can change the rotational speed stepwise by inverter control, and can adjust the blown amount of heated or cooled air. The flow rate adjusting valve plays a role of adjusting the amount of water flowing to the air conditioner. That is, the flow rate of water flowing through each of the first to ninth air conditioners 21 to 29 is determined by the opening degree of each flow rate adjusting valve. Each blower fan and each flow rate adjustment valve are controlled by the air conditioner controller 120.

(2-4) Control Device FIG. 2 is a control block diagram of a control device provided in the load distribution system. The control device mainly includes a chiller system controller 110 and an air conditioner controller 120. As described above, the chiller system controller 110 controls the first to third refrigerators 51 to 53 and the first to third pumps 61 to 63, and the air conditioner controller 120 controls the first to ninth air conditioners 21 to 29. To control.

Note that the detailed configuration related to the startup control of the chiller system controller 110 will be described in detail below.

(3) Operation of the load distribution system (3-1) Overall schematic operation In each of the first to ninth air conditioners 21 to 29, the indoor air taken in from the indoor space by the suction duct (not shown) Flow through air passage. This air is cooled / heated by cold water / hot water flowing from the primary side equipment 10 in each heat exchanger or the like. The cooled / heated air is supplied to the indoor space via an air supply duct (not shown), thereby cooling / heating the indoor space.

(3-2) Startup Control by Chiller System Controller 110 The chiller system controller 110 is mainly composed of a CPU 180 and a memory 190. The memory 190 includes a ROM and a RAM, and various programs and the like that are read and executed by the CPU 180 are stored in the ROM. The RAM functions as a work memory for the CPU 180 and stores information that can be rewritten by the CPU 180.

The chiller system controller 110 can change the number of operating refrigerators according to the load on the secondary equipment 20 (specifically, the thermal load of each indoor space to be processed by the first to ninth air conditioners 21 to 29). Control of the number of refrigerators to be performed is performed as control relating to the first to third refrigerators 51 to 53.

(3-3) Control of the number of refrigerators Next, functions related to the control of the number of refrigerators of the chiller system controller 110 will be described in detail.

As shown in FIG. 2, the CPU 180 that executes the program read from the ROM includes a secondary load amount calculation unit 181 and a refrigerator number determination unit 182 as functional units on the software related to activation control. Will be provided. The memory 190 stores a refrigerator characteristic table 191. In the refrigerator characteristic table 191, information on the types (capacity variable type, constant capacity type, etc.), compressor capacity, operating efficiency, and the like of the first to third refrigerators 51 to 53 is created and input in advance.

The secondary load amount calculation unit 181 calculates a load required by the secondary equipment 20. For example, the secondary load amount calculation unit 181 measures the measured value of the outgoing water temperature sensor 111 that measures the temperature of the water flowing from the primary side equipment 10 to the secondary side equipment 20 every predetermined time, and the secondary side equipment 20. Air conditioner that the secondary side equipment 20 is operating on the basis of the measured value of the return water temperature sensor 112 that measures the temperature of the water flowing from the primary side equipment 10 to the primary side equipment 10 and the amount of circulating water measured by the water quantity sensor 113. The load of the machine, that is, the load required by the secondary equipment 20 (hereinafter referred to as the required load amount) is calculated.

The refrigerator number determining unit 182 determines the number and capacity of the refrigerators to be operated so that the required load amount calculated by the secondary load amount calculating unit 181 is processed. Then, the refrigerator number determining unit 182 controls the first to third pumps 61 to 63 and the first to third refrigerators 51 to 53 according to the determined number and capacity of the refrigerators. In other words, the refrigerator number determining unit 182 has a role as a functional unit for reviewing the refrigerator to be operated from the start control to the end of the start control. Specifically, the refrigerator number determining unit 182 reviews one or a plurality of refrigerators that are already in operation every predetermined time. More specifically, the number-of-refrigerating machine determination unit 182 determines the primary side determined last time when a predetermined time has elapsed based on the measured / estimated load of the secondary equipment 20 while the start-up control is being executed. The operation number and capacity of the refrigerator of the facility 10 are corrected.

Here, using the refrigerator characteristic table 191 stored in the memory 190, the refrigerator number determining unit 182 determines the number and capacity of the refrigerators to be operated. The number of refrigerators determination unit 182 determines the number and capacity (load) of refrigerators by selecting an appropriate combination from the operating combinations of the first to third refrigerators 51 to 53 according to the required load amount. To do.

For example, when the load required from the secondary-side equipment 20 is small, that is, when the required load amount can be processed by operating only the first refrigerator 51, the number-of-freezer determining unit 182 It is determined that only the refrigerator 51 is operated. And when the load requested | required from the secondary side equipment 20 increases gradually and the load more than the load which can be coped with by the 1st freezer 51 is requested | required, ie, only the 1st freezer 51 is operated, a required load When the amount cannot be processed and it is necessary to operate the second refrigerator 52 in addition to the first refrigerator 51, a determination is made to operate the second refrigerator 52 in addition to the first refrigerator 51. When the operation (drive) of the second refrigerator 52 is started, the refrigerator number determining unit 182 causes the flow rate of water to the first refrigerator 51 to be smaller than the flow rate of water to the second refrigerator 52. In addition, the first pump 61 and the second pump 62 are controlled. Then, the capacities of the first refrigerator 51 and the second refrigerator 52 are determined according to the amount of water flowing through the first refrigerator 51 and the second refrigerator 52. After that, when the load required from the secondary side equipment 20 is gradually increased and a load more than the load that can be handled by the first refrigerator 51 and the second refrigerator 52 is required, that is, the first refrigerator 51 and If the required load cannot be processed even if the second refrigerator 52 is operated, and the third refrigerator 53 needs to be operated in addition to the first refrigerator 51 and the second refrigerator 52, the first refrigerator It is determined that the third refrigerator 53 is operated in addition to the machine 51 and the second refrigerator 52. When the operation (drive) of the third refrigerator 53 is started, the refrigerator number determining unit 182 determines that the flow rate of water with respect to the first refrigerator 51 is relative to the second refrigerator 52 and the third refrigerator 53, respectively. The first to third pumps 61 to 63 are controlled so as to be less than the flow rate of water. Then, the capacities of the first to third refrigerators 51 to 53 are determined according to the amount of water flowing to the first to third refrigerators 51 to 53. On the other hand, when the first to third refrigerators 51 to 53 are in operation, the load required from the secondary side equipment 20 is gradually reduced to operate the first refrigerator 51 and the second refrigerator 52. When the required load amount can be processed, the number-of-freezer determining unit 182 determines to stop the operation of the third refrigerator 53 and operate the first refrigerator 51 and the second refrigerator 52. I do. Moreover, when the 1st freezer 51 and the 2nd freezer 52 are driving | operating, the load requested | required from the secondary side equipment 20 reduces gradually, and a required load is made to drive only the 1st freezer 51. When the amount can be processed, the refrigerator number determining unit 182 determines to stop the operation of the second refrigerator 52 and operate only the first refrigerator 51.

In the present embodiment, when the refrigerator to be operated is determined, the refrigerator number determining unit 182 operates the pump that supplies water to the operated refrigerator with a predetermined capacity and supplies water to the refrigerator that is not operated. Stop pump operation.

(3-4) Flow of Control of Number of Refrigerators Each step of control of the number of chillers by the chiller system controller 110 will be described with reference to FIG. In the following description, 100% capacity of each refrigerator means the rated capacity of each refrigerator.

In the control of the number of refrigerators, as described above, the secondary side load amount calculation unit 181 calculates the load of the secondary side equipment 20 based on the temperature of the outgoing water, the temperature of the circulating water, and the amount of water, and based on that. The refrigerator number determining unit 182 determines the number and capacity of refrigerators to be operated.

First, in step S11, it is determined to operate the first refrigerator 51, and only the first refrigerator 51 is operated. Specifically, the first pump 61 is controlled so that the water temperature on the outlet side of the first refrigerator 51 becomes a set temperature, and the variable speed compressor is driven with a predetermined capacity (inverter output). Then, the process proceeds to step S12.

In step S12, the secondary load amount calculation unit 181 and the refrigerator number determination unit 182 determine whether or not the capacity of the first refrigerator 51 has reached 100%. Then, when it is determined in step S12 that the capacity of the first refrigerator 51 has reached 100%, the process proceeds to step S13. On the other hand, if it is determined in step S12 that the capacity of the first refrigerator 51 has not reached 100%, the process returns to step S12.

In step S13, the refrigerator number determining unit 182 determines the start of operation of the second refrigerator 52 in addition to the first refrigerator 51, and proceeds to step S14. In step S14, when the capacity of the first pump 61 is not fixed at the minimum capacity (here, the minimum capacity that can be exhibited based on the pump characteristics), the capacity of the first pump 61 is fixed at the minimum capacity. At the same time, the capacity of the first refrigerator 51 is determined to be the capacity according to the flow rate. Further, when the operation of the second refrigerator 52 has not been started, the second pump 62 is started to be driven and the compression provided in the second refrigerator 52 in order to start the operation of the second refrigerator 52. Start the machine. As a result, the first refrigerator 51 and the second refrigerator 52 are operated, and an amount of water that flows with the minimum capacity of the first pump 61 flows to the first refrigerator 51, and the remaining water flows to the second. It will flow to the refrigerator 52. Then, the process proceeds to step S15.

In step S15, the secondary load amount calculation unit 181 and the refrigerator number determination unit 182 determine whether or not the capacity of the second refrigerator 52 has reached 100%. If it is determined in step S15 that the capacity of the second refrigerator 52 has reached 100%, if the capacity of the first pump 61 is not released, the capacity of the first pump 61 is determined in step S16. While releasing the fixation, the first pump 61 is controlled so that the capacity of the second refrigerator 52 is maintained at 100%. Thereafter, the process proceeds to step S19. On the other hand, if it is determined in step S15 that the capacity of the second refrigerator 52 has not reached 100%, in step S17, the capacity of the second refrigerator 52 continues for a certain time or more and is less than 85%. Judge whether or not. If it is determined in step S17 that the capacity of the second refrigerator 52 continues to be less than 85% for a predetermined time or longer, the refrigerator in which the refrigerator number determining unit 182 is operated is determined as the first refrigerator in step S18. The refrigerator 51 is determined, that is, the second refrigerator 52 is determined to be reduced, and the driving of the second refrigerator 52 and the second pump 62 is stopped. As a result, only the first refrigerator 51 is operated. Then, it returns to step S12. On the other hand, if it is determined in step S17 that the capacity of the second refrigerator 52 continues for a certain time or more and is not less than 85%, the process returns to step S14.

In step S19, the secondary load amount calculation unit 181 and the refrigerator number determination unit 182 determine whether the respective capacities of the first refrigerator 51 and the second refrigerator 52 have reached 100%. When it is determined in step S19 that the capacities of the first refrigerator 51 and the second refrigerator 52 have reached 100%, the process proceeds to step S20. On the other hand, if it is determined in step S19 that the capacities of the first refrigerator 51 and the second refrigerator 52 have not reached 100%, the process returns to step S17.

In step S20, the refrigerator number determining unit 182 determines the start of operation of the third refrigerator 53 in addition to the first refrigerator 51 and the second refrigerator 52, and the capacity of the first pump 61 is fixed at the minimum capacity. If not, in step S21, the capacity of the first pump 61 is fixed to the minimum capacity, and the capacity of the first refrigerator 51 is determined as the capacity corresponding to the flow rate. Further, when the operation of the third refrigerator 53 has not been started, the third pump 63 is started to be driven and the compression provided by the third refrigerator 53 is started in order to start the operation of the third refrigerator 53. Start the machine. As a result, the first to third refrigerators 51 to 53 are operated, and the first refrigerator 51 is supplied with an amount of water that flows with the minimum capacity of the first pump 61, and the remaining water is supplied to the second refrigerator. It will flow equally to the machine 52 and the third refrigerator 53. Then, the process proceeds to step S22.

In step S22, the secondary load amount calculation unit 181 and the refrigerator number determination unit 182 determine whether the respective capacities of the second refrigerator 52 and the third refrigerator 53 have reached 100%. And when it is judged that the capacity | capacitance of the 2nd refrigerator 52 and the 3rd refrigerator 53 reached | attained 100% in step S22, when the capacity | capacitance fixation of the 1st pump 61 is not cancelled | released, in step S23, The first pump 61 is controlled so that the capacities of the first pump 61 are released and the capacities of the second refrigerator 52 and the third refrigerator 53 are maintained at 100%, and the process returns to step S22. On the other hand, when it is determined in step S22 that the capacities of the second refrigerator 52 and the third refrigerator 53 have not reached 100%, in step S24, the capacities of the third refrigerator 53 continue for a certain time or more. It is judged whether it is less than 92.5%. If it is determined in step S24 that the capacity of the third refrigerator 53 continues for a certain time or more and is less than 92.5%, the refrigerator in which the refrigerator number determining unit 182 is operated in step S25. The first refrigerator 51 and the second refrigerator 52 are determined, that is, it is determined to reduce the third refrigerator 53, and the process returns to step S16. As a result, the first refrigerator 51 and the second refrigerator 52 are operated, and the operation of the third refrigerator 53 is stopped. On the other hand, if it is determined in step S24 that the capacity of the third refrigerator 53 continues for a certain time or more and is not less than 92.5%, the process returns to step S21.

(4) Features (4-1)
Here, as a result of intensive studies, the present inventors have determined that each heat source machine is a system in which a heat source machine having a variable speed compressor and a heat source machine having a constant speed compressor or an endothermic heat source machine are arranged in parallel. In combination with the heat source device having a constant speed compressor or the heat absorption type heat source device, whether the heat medium is flown by a variable capacity pump, the heat medium is flown by a constant speed pump, It has been found that there is almost no difference in the flow rate of the heat medium flowing through the heat source device having a constant speed compressor or the endothermic heat source device due to the pressure with the pump.

In the present embodiment, water is supplied from the first pump 61, which is a variable capacity pump, to the first refrigerator 51, which is a variable capacity type heat source apparatus, and the second refrigerator 52, which is a constant capacity type heat source apparatus. The third refrigerator 53 is supplied with water from the second pump 62 and the third pump 63 which are constant speed pumps. Regardless of whether the heat medium is flown by a capacity variable type pump or the constant speed pump, the heat source machine of constant capacity type is changed to a heat source machine of constant capacity type due to the pressure with other pumps. Since there is almost no difference in the flow rate of the flowing heat medium, the second refrigerator 52 and the third refrigerator 52 and the third refrigerator 53 are supplied with the same amount of water as when the water flows from the variable capacity pump. It can flow to the third refrigerator 53. Furthermore, since the constant speed pump is generally less expensive than the variable displacement pump, the constant speed pump is compared with a case where water flows through the second refrigerator 53 and the third refrigerator 53 by the variable displacement pump. Cost.

This makes it possible to suppress an increase in cost and to appropriately set the load distribution for each refrigerator.

(4-2)
FIG. 4 is a schematic configuration diagram of a primary-side facility provided in a load distribution system as a conventional technique. FIG. 5 is a diagram for explaining the energy loss of each of the load distribution system according to the present embodiment and the load distribution system as the prior art. In addition, in FIG. 5, the energy loss range in each of the load distribution system which concerns on this embodiment, and the load distribution system as a prior art is typically shown by hatching. Further, in FIG. 5, the capacity ratio between the constant speed pumps (second pump 62 and third pump 63) and the variable displacement pump (first pump 61) is the maximum due to the characteristics of the pump. Therefore, the energy loss range is shown in the case where the minimum capacity of the variable capacity pump at the time of starting the heat source apparatus of constant capacity is 50%.

The conventional load distribution system is the same as that of the present embodiment except that a constant speed pump is employed as the first pump 61 ′ in the heat medium circulation circuit 70 included in the load distribution system according to the present embodiment. It is assumed to be a configuration. Then, the refrigerators to be operated are determined in the order of the first refrigerator 51 ′, the second refrigerator 52 ′, and the third refrigerator 53 ′ so that the required load amount from the secondary equipment is processed. To do.

Here, when the variable capacity type heat source unit is operated, the power consumption increases or decreases depending on the capacity. However, when the constant capacity type heat source unit is operated, the power consumption is the same regardless of the capacity. . For this reason, wasteful power consumption can be suppressed by adjusting the amount of the heat medium flowing through the constant-capacity type heat source unit so that the capability of the constant-capacity type heat source unit can be maximized.

In the load distribution system as the prior art, the amount of water flowing to the first refrigerator 51 ′ to the third refrigerator 53 ′ cannot be adjusted, so that the second refrigerator 52 ′ is operated in addition to the first refrigerator 51 ′. Is started, an equal amount of water flows through each of the first refrigerator 51 ′ and the second refrigerator 52 ′. If it does so, as shown in FIG. 5, the capability of a constant capacity type heat source machine (2nd freezer 52 ') will be lost by 50% at maximum. Further, when the operation of the third refrigerator 53 ′ is started in addition to the first refrigerator 51 ′ and the second refrigerator 52 ′, an equal amount is added to each of the first to third refrigerators 51 ′ to 53 ′. Water flows. Then, as shown in FIG. 5, the capacity of the constant capacity type heat source machine (the second refrigerator 52 'and the third refrigerator 53') is lost up to about 67%.

In the present embodiment, the pump that supplies water to the first refrigerator 51 ′, which is a variable capacity heat source machine, is a variable capacity pump. The minimum capacity of the first pump 61 can be determined based on the pump characteristics of the first to third pumps 61 to 63. For this reason, when starting the operation of the second refrigerator 52 in addition to the first refrigerator 51, an amount of water flowing with the minimum capacity of the first pump 61 is caused to flow to the first refrigerator 51, and the remaining water Can flow to the second refrigerator 52. Thereby, when starting the operation of the second refrigerator 52 in addition to the first refrigerator 51, as shown in FIG. 5, the capacity loss of the constant-capacity heat source unit (second refrigerator 52) is reduced. The maximum is 33%. Further, when starting the operation of the third refrigerator 53 in addition to the first refrigerator 51 and the second refrigerator 52, an amount of water flowing with the minimum capacity of the first pump 61 is supplied to the first refrigerator 51. The remaining water can be allowed to flow to the second refrigerator 53 and the third refrigerator 53. As a result, when starting the operation of the third refrigerator 53 in addition to the first refrigerator 51 and the second refrigerator 52, as shown in FIG. And the loss of capacity of the third refrigerator 53) is 40% at the maximum. As described above, in the present embodiment, the amount of water that flows to the first refrigerator 51 due to the pump characteristics is minimized, and the remaining water is allowed to flow to the second refrigerator 52 and the third refrigerator 53 to reduce the amount of water. Since the capacity of the second refrigerator 52 and the third refrigerator 53 can be maximized, the energy loss of the entire system can be suppressed as compared with the load distribution system as the prior art. .

(4-3)
In this embodiment, since the operation of the first refrigerator 51 is not stopped when the operation of the second refrigerator 52 is started, the compressor can be prevented from being stopped due to the thermo-off in the first refrigerator 51. Thereby, while being able to respond | correspond quickly with respect to the required load amount from the secondary side equipment 20, the shortening of the apparatus lifetime by the increase in the frequency | count of a start / stop of a compressor can be prevented.

(5) Modification (5-1) Modification A
FIG. 6 is a schematic configuration diagram of primary-side equipment included in the load distribution system according to Modification A. FIG. 7 is a diagram for explaining the energy loss of each of the load distribution system according to Modification A and the load distribution system as the prior art. In addition, in FIG. 7, the energy loss range in the load distribution system as a prior art is typically shown by hatching. Further, in FIG. 7, the capacity ratio between the constant speed pumps (second pump 62 and third pump 63) and the variable displacement pump (first pump 61) is the maximum due to the characteristics of the pump. Therefore, the energy loss range is shown in the case where the minimum capacity of the variable capacity pump at the time of starting the heat source apparatus of constant capacity is 50%.

In the above embodiment, only one variable capacity type heat source machine (first refrigerator 51) is provided among the plurality of heat source machines. Instead of this, two or more variable capacity type heat source units may be provided.

For example, in the load distribution system according to Modification A, as shown in FIG. 6, the first refrigerator 251 and the second refrigerator 252 are variable capacity heat source machines, and the third refrigerator 253 has a constant capacity. It is a heat source machine of the type. The first pump 261 and the second pump 262 are variable displacement pumps, and the third pump 263 is a constant speed pump. And the 1st freezer 251, the 2nd freezer 252, and the 3rd freezer 253 are determined in order of the refrigerating machine to operate so that the demand load amount from the secondary side equipment may be processed. It is assumed that the minimum capacities of the first refrigerator 251 and the second refrigerator 252 that are variable capacity heat source machines are 15%, respectively. That is, in this modification, the total capacity of the first refrigerator 251 and the second refrigerator 252 is equal to or less than the rated capacity of the third refrigerator 253.

On the other hand, the load distribution system as the prior art shown in FIG. 7 is the heat medium circulation circuit provided in the load distribution system according to this modification, except that constant speed pumps are employed as the first pump and the second pump. It is assumed that the configuration is the same as that of the present modification. And it shall determine in order of a 1st freezer, a 2nd freezer, and a 3rd freezer as a freezer to be operated so that a demand load amount from a secondary side equipment may be processed.

The load distribution system as the prior art includes the first refrigerator and the second refrigerator as variable capacity heat source machines with a minimum capacity of 15%, but the amount of water flowing to the first to third refrigerators is adjusted. Therefore, when the operation of the third refrigerator is started in addition to the first refrigerator and the second refrigerator, an equal amount of water flows through each of the first to third refrigerators. If it does so, as shown in FIG. 7, the capacity | capacitance of a 3rd refrigerator will be lost about 33% at maximum.

On the other hand, in this modification, the pumps that supply water to the first refrigerator 251 and the second refrigerator 252 that are variable capacity heat source machines are variable capacity pumps. The minimum capacities of the first pump 261 and the second pump 262 can be determined based on the pump characteristics of the first to third pumps 261 to 263. For this reason, when starting the operation of the third refrigerator 253 in addition to the first refrigerator 251 and the second refrigerator 252, the amount of water flowing with the minimum capacity of the first pump 261 and the second pump 262 is increased. It is possible to flow to the first refrigerator 251 and the second refrigerator 252, and to flow the remaining water to the third refrigerator 253. Accordingly, when the operation of the third refrigerator 53 is started in addition to the first refrigerator 51 and the second refrigerator 52, the capacity of the third refrigerator 253 can be maximized. As shown in FIG. 3, the loss of the third refrigerator 253 can be eliminated.

In this way, in the multiple heat source units with which the load distribution system is equipped, the total capacity of the minimum capacity of the variable capacity type heat source unit is equal to or less than the rated capacity of the constant capacity type heat source unit. When starting the operation of the constant capacity type heat source apparatus in addition to the heat source apparatus, the energy loss of the entire system can be suppressed by adjusting the flow rate of the heat medium to the variable capacity type heat source apparatus.

Moreover, in the said embodiment, although the example provided with three refrigerators as a heat source apparatus which heats or cools a heat medium is shown, the number of heat source apparatuses is not limited to this, One or several units | sets are provided. It is only necessary that the variable capacity type heat source apparatus and one or a plurality of constant capacity type heat source apparatuses are provided in parallel. Further, the number of air conditioners that are heat utilization devices is not limited to the above embodiment.

(5-2) Modification B
FIG. 8 is a schematic configuration diagram of primary-side equipment included in the load distribution system according to Modification B. FIG. 9 is a diagram for explaining the energy loss of each of the load distribution system according to Modification B and the load distribution system as the prior art. In addition, in FIG. 9, the energy loss range in the load distribution system which concerns on this modification, and the load distribution system as a prior art is typically shown by hatching. The minimum capacity of the first refrigerator 51, which is a variable capacity heat source machine, is assumed to be 15%. It is assumed that the load distribution system as a conventional technique has the same configuration as the system including the primary side equipment shown in FIG.

In addition to the above embodiment, a bypass path may be provided that returns the heat medium after passing through the variable capacity heat source apparatus to the upstream side of the pump that supplies the heat medium to the variable capacity heat source apparatus. .

For example, as shown in FIG. 8, a bypass pipe 174 serving as a bypass path connecting the downstream side (exit side) of the first refrigerator 51 and the upstream side (inlet side) of the first pump 61 is water in the return header 12. Will be described as being connected to a first pipe 74 as a path through which the gas flows to the forward header 11 via the first pump 61 and the first refrigerator 51. The bypass pipe 174 is provided with a flow rate adjustment valve 174a. The flow rate adjusting valve 174 a can adjust the flow rate of water that passes through the first refrigerator 51 and returns to the upstream side of the first pump 61 by changing the opening degree. For this reason, by adjusting the flow rate adjustment valve 174a, the amount of water flowing to the constant capacity heat source machine (second refrigerator 52 or third refrigerator 53) out of the total amount of water circulating in the heat medium circulation circuit is reduced. Can be increased. And since the capability of the 1st freezer 51 can be reduced to the minimum capability, as shown in Drawing 9, in addition to the 1st freezer 51, the operation of the 2nd freezer 52 is started, and the 1st freezer When the operation of the third refrigerator 53 is started in addition to the machine 51 and the second refrigerator 52, the capacity loss of the constant capacity type heat source machine (the second refrigerator 52 or the third refrigerator 53) is the largest. 15%.

As described above, in this modification, a bypass path is provided to return the heat medium after passing through the variable capacity type heat source apparatus to the upstream side of the pump that supplies the heat medium to the variable capacity type heat source apparatus. Therefore, since the capacity of the variable capacity type heat source machine can be fixed to the minimum capacity, the capacity of the constant capacity type heat source machine can be maximized. Thereby, compared with the load distribution system as a prior art, the energy loss (loss) of the whole system can be suppressed.

In addition, there is not only a bypass path for returning the heat medium after passing through the variable capacity type heat source machine to the upstream side of the pump that supplies the heat medium to the variable capacity type heat source apparatus. A bypass path is provided to return the heat medium after passing through the heat source unit to the upstream side of the pump that supplies the heat medium to the constant capacity type heat source unit, and supplies the heat medium to the constant capacity type heat source unit. In a system having a primary-side facility in which a variable capacity pump is employed as a pump to perform the heat transfer, a heat medium that is heat-exchanged by a constant-capacity type heat source unit is used in order to perform appropriate load distribution to each heat source unit. When bypass control is performed without sending to the next-side equipment, the power of the pump that supplies the heat medium to the heat source unit with a constant capacity is wasted. In addition, when the primary equipment is renewed in the configuration where a constant speed pump is used as a pump for supplying a heat medium to a constant capacity heat source machine (when a refrigerator is replaced or added). ), The pump for supplying the heat medium to the heat source device with a constant capacity must be changed from a constant speed pump to a variable displacement pump, resulting in an increase in cost.

On the other hand, when the primary equipment with a constant-speed pump is used as a pump for supplying a heat medium to a constant-capacity heat source machine (when replacing or adding a refrigerator), By adopting the configuration of the primary side equipment provided in such a system, it is not necessary to change the pump that supplies the heat medium to the heat source unit with a constant capacity, and all the heat exchanged by the heat source unit with the constant capacity is performed. Since the heat medium is sent to the secondary equipment, it is possible to suppress an increase in cost at the time of renewal and to suppress waste of pump power during operation.

The present invention is capable of suppressing an increase in cost and appropriately setting load distribution for each heat source unit, and has a heat source unit having a variable speed compressor and a constant speed compressor as a plurality of heat source units. Application to a system including a heat source machine or an absorption heat source machine is effective.

11 Outbound header 12 Return header 20 Secondary side equipment (use side equipment)
51 First refrigerator (first heat source machine)
52 Second refrigerator (second heat source machine)
61 1st pump 62 2nd pump 182 Refrigerator number determination part (control part)

JP 2010-127559 A

Claims

A first heat source machine (51) for heating or cooling the heat medium;
A second heat source unit (52) that heats or cools the heat medium and is arranged in parallel with the first heat source unit;
A first pump (61) capable of changing a discharge capacity of the heat medium and flowing the heat medium to the first heat source unit;
A second pump (62) in which the discharge capacity of the heat medium per unit time is constant, and the heat medium flows to the second heat source unit;
A use side facility (20) to which a heat medium is supplied from the first heat source machine and the second heat source machine;
A control unit (182) for controlling the number of driven first heat source units and the second heat source unit according to the load required from the use side facility,
With
The first heat source machine is a heat source machine having a variable speed compressor,
The second heat source machine is a heat source machine having a constant speed compressor or an absorption heat source machine,
When the load required from the use-side facility gradually increases and a load greater than the load that can be handled by the first heat source device is requested, the control unit transfers the heat medium to the second heat source device. And the first pump is driven so that the flow rate of the heat medium to the first heat source unit is smaller than the flow rate of the heat medium to the second heat source unit. Control,
Load distribution system.
There are two or more first heat source machines,
The total capacity of the minimum capacity of the first heat source machine is less than or equal to the rated capacity of the second heat source machine.
The load distribution system according to claim 1.
A forward header (11) for mixing the heat medium flowing out from the first heat source device and the second heat source device;
A return header (12) through which a heat medium heat-exchanged in the user-side equipment flows back;
A first path through which the heat medium of the return header flows to the forward header via the first pump and the first heat source unit;
A bypass path which is provided in the first path and returns the heat medium after passing through the first heat source unit to the upstream side of the first pump;
Including a heat medium circulation circuit,
The load distribution system according to claim 1 or 2.