KR101702178B1 - Chiller system - Google Patents

Abstract

The present invention relates to a chiller system.
A chiller system according to one aspect comprises: a plurality of chiller modules each comprising a compressor, a condenser and an evaporator; And a controller for controlling the plurality of chiller modules, the controller determining an expected load, determining a chiller module to operate among the plurality of chiller modules based on the determined expected load, and operating the determined chiller module.

Description

Chiller system

The present specification relates to a chiller system.

Generally, a chiller supplies cold water to a cold water consumer, and is characterized in that heat exchange is performed between a refrigerant circulating in a refrigeration system and cold water circulating between a cold water consumer and a refrigeration system to cool the cold water. The chiller is a large-capacity facility and can be installed in a large-scale building.

1 is a view showing a conventional chiller system.

Referring to FIG. 1, a conventional chiller system 1 includes a chiller unit and a demander 6. The customer 6 can be understood as an air conditioner using cold water as an example.

The chiller unit includes a compressor 2 for compressing refrigerant, a condenser 3 for condensing the refrigerant compressed in the compressor 2, an expansion device 4 for decompressing the refrigerant condensed in the condenser 3, And an evaporator (5) for evaporating the refrigerant decompressed in the expansion device (4).

The refrigerant is heat-exchanged with the outside air in the condenser (3), and can be heat-exchanged with the cold water in the evaporator (5).

The chiller system 1 includes a cold water pipe 8 for guiding the circulation of cold water by connecting the evaporator 5 and the customer 6 and a pump for supplying the cold water to the cold water pipe 8, (7).

When the pump 7 is operated, cold water can flow from the demander 6 to the evaporator 5 and from the evaporator 5 to the consumer 6 via the cold water pipe 8 have.

The evaporator (5) is provided with a refrigerant passage (5a) through which refrigerant flows and a cold water passage (5b) through which cold water flows. The coolant in the coolant channel 5a and the coolant in the coolant channel 5b may be indirectly heat-exchanged with each other.

The chiller unit may be provided in various sizes or capacities. Here, the size or the capacity of the chiller unit may be expressed in units of a freezing tone (RT) as a concept corresponding to the capability of the refrigeration system, that is, the refrigeration capacity.

The conventional chiller unit may be equipped with various refrigeration tones according to the size of a building or the like where the chiller unit is installed, the capacity of the circulating cold water, the air conditioning capacity, or the like. For example, the chiller unit may have a capacity of 1000RT, 1500RT, 2000RT, 3000RT, or the like.

Generally, as the capacity of the chiller unit increases, the volume of the chiller unit becomes larger.

Once the size of the building on which the chiller unit is installed or the required air conditioning capacity is determined, the capacity of the chiller unit is determined and the chiller unit is built based on the determined capacity.

However, since the chiller unit is a large-capacity facility, it takes several months for the production to be completed after the specific capacity is determined, and the consumer is complaining about the production period.

In addition, when the chiller unit is broken during the use of the chiller system, the operation of the entire chiller unit is limited, and it takes a long time to repair the chiller unit, thereby limiting the air conditioning operation of the building.

It is an object of the present invention to provide a chiller system with good product productivity and market responsiveness.

It is another object of the present invention to provide a chiller system capable of sequentially operating a plurality of compressors.

A chiller system according to one aspect comprises: a plurality of chiller modules each comprising a compressor, a condenser and an evaporator; And a controller for controlling the plurality of chiller modules, the controller determining an expected load, determining a chiller module to operate among the plurality of chiller modules based on the determined expected load, and operating the determined chiller module.

The plurality of chiller modules may have different capacities.

In addition, the controller may operate some or all of the plurality of chiller modules based on the expected load.

The controller also determines the expected load based on an expected load factor and an expected rate of rise and the expected load factor is determined based on the temperature of the cold water entering the evaporator and the target cold water outlet temperature, , The temperature of the cooling water flowing into the condenser, and the target cold water outflow temperature.

The plurality of chiller modules may include a first chiller module and a second chiller module having a capacity greater than the capacity of the first chiller module. When the first chiller module determines that the operation method should be changed In this case, the controller may stop the first chiller module and activate the second chiller module, or may operate the first and second chiller modules together.

The plurality of chiller modules may include a first chiller module and a second chiller module having a capacity larger than the capacity of the first chiller module. When it is determined that the operation method should be changed in the course of operating the second chiller module The controller may stop the second chiller module and activate the first chiller module, or may operate the first and second chiller modules together.

The judgment criteria for judging whether or not an operation change is necessary includes a judgment criterion when the expected load is increased and a judgment criterion when the expected load is reduced.

The controller also determines whether an operation change is required based on the expected load factor and the predicted rate of change, and the expected load factor is determined based on the temperature of the cold water discharged from the evaporator and the target cold water outlet temperature, Rate can be determined based on the temperature of the cooling water flowing into the condenser and the target cold water outflow temperature.

In addition, if it is determined that the operation object is to be changed by the second chiller module during the operation of the first chiller module, the controller performs an activation sequence of the second chiller module, and after the activation sequence of the second chiller module is completed, The operation of the first chiller module can be stopped.

In addition, when it is determined that the operation target is changed by the first chiller module during the operation of the second chiller module, the controller reduces the opening of the guide vane of the second compressor, and when the opening of the guide vane reaches the reference opening The startup sequence of the first chiller module can be performed.

In addition, the controller may stop the operation of the second chiller module after the startup sequence of the first chiller module is completed.

A chiller system according to another aspect includes: a first chiller module having a first compressor; A second chiller module having a capacity larger than the capacity of the first chiller module and having a second compressor; And a controller for controlling the first chiller module and the second chiller module. When the controller determines that an operation start command has been input, the controller controls the first chiller module and the second chiller module to operate, And causes the determined chiller module to start operating.

According to another aspect, a chiller system includes a first chiller module having a first compressor; A second chiller module having a capacity larger than the capacity of the first chiller module and having a second compressor; And a controller for controlling the first and second chiller modules and the second chiller module, wherein, when at least one of the first and second chiller modules is operating, if the controller determines that the operation method should be changed , Stop the activated chiller module and allow another chiller module to operate, stop any chiller module while all chiller modules are in operation, or activate the remaining chiller module while one chiller module is operating.
Another aspect of the chiller system includes a plurality of chiller modules each comprising a compressor, a condenser and an evaporator; And a controller for controlling the plurality of chiller modules, the controller determining an expected load, determining a chiller module to operate among the plurality of chiller modules based on the determined expected load, operating the determined chiller module, The controller operates some or all of the plurality of chiller modules based on the expected load, wherein the expected load is determined by the cooling water temperature flowing through the condenser and the cold water temperature flowing through the evaporator.

According to the proposed invention, since the chiller system is provided in a modularized form, the chiller set can be manufactured quickly and effectively according to the size of the building where the chiller system is installed or the necessary air conditioning ability.

In addition, even if some chiller modules fail during the use of the chiller system, only the failed chiller module can be repaired or replaced, thereby preventing the chiller system from being operated for a long period of time.

In addition, there is an advantage in that it can cope with load effectively by performing logarithmic control using a plurality of chiller modules having different capacities.

Also, in the present invention, frequent on / off repetition of the chiller module can be prevented by differentiating the operation method change judgment criterion at the time of the load increase and the operating method change criterion at the time of the load decrease.

1 is a view showing a conventional chiller system.
2 is a diagram illustrating a configuration of a chiller system according to an embodiment of the present invention.
3 is a system diagram showing a configuration of a chiller module according to an embodiment of the present invention.
4 is a conceptual diagram of the chiller module of Fig.
5 is a perspective view illustrating a chiller set according to an embodiment of the present invention;
6 is a flow chart for explaining a control method in an initial operation of a chiller set according to an embodiment of the present invention;
7 is a flowchart illustrating a method of controlling a chiller set according to a load variation during operation of a chiller set according to an embodiment of the present invention.
8 is a graph showing the algebraic control standard of the chiller module according to the lift rate and the load ratio.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals whenever possible, even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; may be "connected," "coupled," or "connected. &Quot;

FIG. 2 is a diagram illustrating the configuration of a chiller system according to an embodiment of the present invention. FIG. 3 is a system diagram illustrating a configuration of a chiller module according to an embodiment of the present invention. It is a conceptual diagram.

2 to 4, a chiller system 10 according to an embodiment of the present invention includes a chiller module 100 in which a refrigeration cycle is formed, a cooling tower 20 for supplying cooling water to the chiller module 100, And a cold water consumer 30 through which cold water to be heat-exchanged with the chiller module 100 is circulated.

The cold water consumer 30 may be understood as a device or a space for performing air conditioning using cold water.

Between the chiller module 100 and the cooling tower 20, a cooling water circulating flow passage 40 is provided. The cooling water circulating passage 40 is a pipe for guiding the cooling water to circulate through the cooling tower 20 and the condenser 120 of the chiller module 100.

The cooling water circulating flow path 40 includes a cooling water intake flow path 42 for guiding the cooling water to flow into the condenser 120 and a cooling water outflow path 42 for guiding the cooling water heated in the condenser 120 to flow into the cooling tower 20. [ And may include a flow path 44.

At least one of the cooling water intake flow path 42 and the cooling water outflow flow path 44 may be provided with a cooling water pump 46 driven to flow the cooling water. For example, in FIG. 2, the cooling water intake flow path 42 is shown as being provided with the cooling water pump 46.

The cooling water outflow channel 44 is provided with a cooling water outflow temperature sensor 47 for sensing the temperature of the cooling water flowing into the cooling tower 20. The cooling water intake flow path 42 is provided with a cooling water intake temperature sensor 48 for sensing the temperature of the cooling water discharged from the cooling tower 20.

A cold water circulating passage (50) is provided between the chiller module (100) and the cold water consumer (30). The cold water circulation passage 50 is a pipe for guiding the cold water to circulate through the cold water consumer 30 and the evaporator 140 of the chiller module 100.

The cold water circulation passage 50 includes a cold water intake passage 52 for guiding cold water into the evaporator 140 and a cold water supply passage 52 for guiding the cold water cooled in the evaporator 140 to flow into the cold water consumer 30. [ And an outflow channel 54.

A cold water pump (56) driven for the flow of cold water may be provided in at least one of the cold water inlet flow path (52) and the cold water outlet flow path (54). For example, in FIG. 2, it is shown that the cold water supply flow path 52 is provided with the cold water pump 56.

The chilled water inlet passage 52 is provided with a cold water inlet temperature sensor 53 for sensing the temperature of the cold water flowing into the chiller module 100. The chilled water outlet passage 54 is connected to the chiller module 100, A cold water outflow temperature sensor 55 for sensing the temperature of the cold water may be provided.

As another example, the cold water inlet temperature sensor 53 and the cold water outlet water temperature sensor 55 may be provided in the chiller module 100.

The cold water consumer 30 may be a water-cooled air conditioner for exchanging air with cold water.

For example, the cold water consumer 30 includes an air handling unit (AHU) (Air Handling Unit) that mixes indoor air and outdoor air and then discharges the mixed air by exchanging heat with cold water, A fan coil unit (FCU) for discharging the air into the room after heat exchange with the indoor unit, and a bottom piping unit embedded in the floor of the room.

In Fig. 2, for example, the cold water consumer 30 is shown as being composed of an air handling unit.

Specifically, the air handling unit includes a casing 61, a cold water coil 62 provided inside the casing 61 and through which cold water passes, and a cooling water pipe 62 provided on both sides of the cold water coil 62, And air blowers 63 and 64 for blowing air into the room.

The blowers 63 and 64 include a first blower 63 for allowing indoor air and outdoor air to be sucked into the casing 61 and a second blower 63 for blowing out air to the outside of the casing 61. [ (64).

An indoor air suction unit 65, an indoor air discharge unit 66, an ambient air suction unit 67 and an air conditioning air discharge unit 68 are formed in the casing 61.

When the blowers 63 and 64 are driven, a part of the air sucked into the indoor air suction unit 65 from the room is discharged to the indoor air discharge unit 66 and discharged to the indoor air discharge unit 66 And the remaining air is mixed with outdoor air sucked into the outside air suction unit 67 and exchanges heat with the cold water coil 62.

The mixed air that has been exchanged (cooled) with the cold water coil 62 can be discharged to the room through the air conditioning air discharge unit 68.

The chiller module 100 includes a compressor 110 for compressing a refrigerant, a condenser 120 for introducing high-temperature and high-pressure refrigerant compressed by the compressor 110, a condenser 120 for condensing the refrigerant condensed in the condenser 120, And an evaporator 140 for evaporating the refrigerant decompressed in the expansion devices 131 and 132. The evaporator 140 may be a condenser,

The expansion devices 131 and 132 include a first expansion device 131 that primarily expands the refrigerant discharged from the condenser 120 and a second expansion device 132 that secondarily expands the refrigerant separated from the economizer 150 Device 132 as shown in FIG.

The chiller module 100 includes a suction pipe 101 provided at an inlet side of the compressor 110 and guiding the refrigerant discharged from the evaporator 140 to the compressor 110, And a discharge pipe (102) provided on the side of the condenser (120) for guiding the refrigerant discharged from the compressor (110) to the condenser (120).

An oil return pipe 108 may be provided between the evaporator 140 and the compressor 110 to guide the oil present in the evaporator 140 to the suction side of the compressor 110 .

The compressor (110) includes an impeller (111) for compressing the refrigerant. Also, the compressor 110 includes a motor 112 for driving the impeller 111. The compressor 110 may include one or more gears for transmitting the driving force of the motor 112 to the impeller 111 side.

The compressor 110 may include a guide vane 114 for adjusting the flow rate of refrigerant flowing into and out of the impeller 111. That is, the guide vane 114 can control the opening of the path through which the refrigerant flows, and the flow rate of the refrigerant can be adjusted according to the opening degree adjustment. For example, when the opening degree of the guide vane 114 increases, the flow rate of the refrigerant increases, and when the opening degree decreases, the flow rate of the refrigerant decreases.

The condenser 120 and the evaporator 140 may be configured as a shell and tube heat exchanger so as to allow heat exchange between the refrigerant and water.

The condenser 120 includes a shell 121 forming an outer shell and a coolant inlet 122 formed at one side of the shell 121 and through which the refrigerant compressed by the compressor 110 flows, 121 and a refrigerant outlet 123 through which the refrigerant condensed in the condenser 120 flows out.

The condenser 120 includes a cooling water tube array 124 provided inside the shell 121 and guiding the flow of cooling water and a cooling water tube array 124 formed at one side of the end of the shell 121, And a cooling water outlet 126 formed at the other end of the shell 121 to allow cooling water to flow out from the cooling water tube array 124 .

The cooling water inflow part 125 is connected to the cooling water intake flow path 42 and the cooling water outflow part 126 is connected to the cooling water outflow path 44.

On the coolant outlet side of the condenser 120, an economizer 150 is provided. The first expansion device 131 is provided at the inlet side of the economizer 150. The refrigerant condensed in the condenser 120 flows into the economizer 150 after the first refrigerant is firstly absorbed by the first expansion device 131.

The economizer 150 may separate the liquid refrigerant and the gaseous refrigerant from the first reduced-pressure refrigerant. The separated gaseous refrigerant flows into the compressor (110), and the separated liquid refrigerant flows into the second expansion device (132) and can be secondarily reduced in pressure.

The evaporator 140 includes a shell 141 forming an outer appearance and a coolant inlet 142 formed at one side of the shell 141 and through which the refrigerant expanded in the second expansion device 132 flows, And a refrigerant outlet 143 formed on the other side of the evaporator 140 and through which refrigerant evaporated in the evaporator 140 flows out. The refrigerant outlet 143 may be connected to the suction pipe 101.

The evaporator 140 includes a cold water tube array 144 provided inside the shell 141 to guide the flow of cold water and a cold water tube array 144 formed at one end of the shell 141 and connected to the cold water tube array 144 And a cold water outlet 146 formed at the other end of the shell 141 to allow the cold water to flow out of the cold water passage 145.

The cold water inflow portion 147 is connected to the cold water inflow passage 52 and the cold water outflow portion 148 is connected to the cold water outflow passage 54.

5 is a perspective view illustrating a chiller set according to an embodiment of the present invention.

Referring to FIG. 5, the chiller set according to an embodiment of the present invention may include a plurality of chiller modules 201 and 202. The plurality of chiller modules 201, 202 may be connected in series or in parallel.

In FIG. 5, for example, a plurality of chiller modules 201 and 202 are connected in parallel.

The plurality of chiller modules 201 and 202 may include a first chiller module 201 and a second chiller module 202. Here, the first chiller module 201 and the second chiller module 202 have the same structure as the chiller module described with reference to FIG. 3 and FIG. In addition, the first and second chiller modules 201 and 202 may have the same capacity and size, or may have different capacities and sizes.

Hereinafter, the capacity of the first chiller module 201 and the capacity of the second chiller module 202 are different from each other, and the capacity of the second chiller module 202 is greater than the capacity of the first chiller module 202 I will explain.

The first chiller module 201 may include a first compressor 210, a first condenser 220 and a second evaporator 240. The second chiller module 202 may include a second compressor 212, A second condenser 222, and a second evaporator 242.

The chiller set may further include a cooling water connection pipe 260 connecting the first condenser 220 and the second condenser 222 and a cooling water connection pipe 260 connecting the first evaporator 240 and the second evaporator 242 And a cold water connection pipe (250).

Here, the cold water connection pipe 250 serves as a passageway for transferring cold water having passed through the cold water tube array of the first evaporator 240 to the second evaporator 242 side. Specifically, the cold water that has passed through the cold water tube array of the first evaporator 240 is joined at the cold water connection pipe 250, and then branched to the cold water tube array of the second evaporator 242.

The cooling water connection pipe 260 serves as a passageway for transferring the cooling water having passed through the cooling water tube array of the first condenser 220 to the second condenser 222 side. Specifically, the cooling water having passed through the cooling water tube array of the first condenser 220 is merged at the cooling water connection pipe 260, and then branched into the cooling water tube array of the second condenser 222.

The first compressor 210, the first evaporator 240, and the first condenser 220 are stacked along the vertical direction of the installation surface of the first chiller module 201, as described above, And the second compressor 212, the second evaporator 242, and the second condenser 222 are disposed in a stacked state along the vertical direction of the installation surface of the second chiller module 200 .

The chiller set may further include a controller 270 for controlling the respective chiller modules 201 and 202. The control panel 270 may be configured to input various control commands and display status information of the chiller modules 201 and 202.

The controller 270 may include a memory 272 for storing various types of information.

Hereinafter, a method of controlling the chiller set of the present embodiment will be described.

FIG. 6 is a flowchart illustrating a control method of the chiller set according to an embodiment of the present invention. FIG. 7 is a flowchart illustrating a control method of the chiller set according to an exemplary embodiment of the present invention. 8 is a graph showing a logarithmic control reference of the chiller module according to the heading rate and the load ratio.

2, 6 and 8, when the operation start command of the chiller system is inputted, the operation of the chiller system is started (S1). That is, the operation of the chiller set is started.

When the operation of the chiller set is started, the controller 270 determines an expected load (S2). Then, based on the determined expected load, a chiller module (or compressor) to be operated is determined (S3).

The expected load can be determined based on the first expected load factor and the first predicted load factor.

Specifically, the first expected load factor may be determined based on the current cold water intake temperature sensed by the cold water intake temperature sensor 53 and the target cold water outflow temperature stored in the memory 272.

For example, the first expected load factor may be determined by the following equation (1).

At this time, the cold water rated temperature difference is a constant stored in the memory 272.

The first predicted rising rate can be determined based on the current cooling water intake temperature sensed by the cooling water intake temperature sensor 48 and the target cold water outflow temperature.

For example, the first predicted heading rate can be determined by the following equation (2).

At this time, the temperature difference of the cooling water, the rated cooling water outflow temperature, and the rated cold water outflow water temperature are constants stored in the memory 272.

The controller 270 compares the determined first expected load factor and the first predicted rate with information stored in the memory 272 to determine the expected load.

Referring to FIG. 8, the memory 272 stores three ranges for determining the predicted load according to the load rate and the rate of change during the initial operation of the chiller set.

In FIG. 8, the left area of the left dotted line is the first initial area, the area between the two dotted lines is the second initial area, and the right area of the right dotted line is the third initial range.

At this time, the left dotted line is the second chiller module operation reference line, and the right dotted line is the first chiller module and the second chiller module operation reference line.

The controller 270 determines the first chiller module 201 as a module to be operated when the first expected load factor and the first predicted rising rate fall within the first range.

The controller 270 determines the second chiller module 202 as a module to be operated when the first expected load factor and the first predicted rising rate belong to the second range.

The controller 270 determines the first chiller module 201 and the second chiller module 202 as modules to be operated when the first expected load factor and the first predicted heading rate fall within the third range.

Then, the controller 270 activates the determined chiller module (or compressor) (S4).

Next, referring to FIGS. 7 and 8, when it is determined that one chiller module operates in the step of FIG. 6, one chiller module (or compressor) operates (S11).

While one chiller module is operating, the controller 270 determines whether it is necessary to change the operation method (S12).

At this time, in order to prevent frequent on / off of the chiller module due to the load variation, one chiller module starts to operate, and after a predetermined time has elapsed, the controller 270 judges whether or not the operation method needs to be changed . The predetermined time may be, for example, one hour, and the predetermined time may be changed depending on the installation environment or location of the chiller system.

If it is determined in step S12 that the operation method needs to be changed, the controller 270 determines a chiller module (or a compressor) to be operated (S13). Then, operation of the determined chiller module (or compressor) is started (S14).

Specifically, the controller 270 determines the expected load based on the second expected load factor and the second predicted load factor, and determines whether the operation method should be changed based on the determined expected load.

The change in operating mode in the present invention means that one additional chiller module is operated while the operated chiller module is changed or one chiller module is operated or one chiller module is stopped while two chiller modules are operating And the like.

The second expected load factor can be determined, for example, based on the difference between the present cold water outflow temperature and the target cold water outflow temperature.

At this time, when the current cold water outflow temperature is higher than the target cold water outflow temperature, the second expected load rate becomes larger, and when the current cold water outflow temperature is lower than the target cold water outflow temperature, the second expected load rate becomes smaller.

The second predicted rising rate can be determined based on the current cooling water intake temperature and the target cold water outlet temperature. Alternatively, the second predicted rate can be determined based on the difference between the condensation pressure and the evaporation pressure.

Referring to FIG. 8, the memory 272 stores five ranges for determining the predicted load according to the load rate and the load rate at the time of operation of the chiller set.

8, the region between the first load reduction reference line and the first load increase reference line is the second operation range, the region between the first load increase reference line and the second load decrease reference line is the first operation range, Region is the third operation range, the region between the second load reduction reference line and the second load increase reference line is the fourth operation range, and the right region of the second load increase reference line is the fifth operation range.

For example, when the second expected load factor and the second predicted rising rate are located in the first operation range or the second operation range while the first chiller module 201 is operating, the controller 270 It is judged that the change of the driving method is unnecessary. In other words, since the capacity of the first chiller module 201 can cope with the load, it is unnecessary to change the operation method.

If the second expected load factor and the second predicted rising rate are located in the third operation range while the first chiller module 201 is operating, the controller 270 may change the operation method . That is, since the capacity of the first chiller module can not cope with the load, it is necessary to change the operation method.

Accordingly, the controller 270 operates the second chiller module 202, which is larger than the capacity of the first chiller module 201, to stop the first chiller module 201. [

Specifically, the controller 270 performs an activation sequence of the second chiller module 202 during operation of the first chiller module 201. The startup sequence of the second chiller module 202 may include an oil circulation sequence in which the oil is circulated into the second compressor 212 of the second chiller module 202 and the opening sequence of the guide vanes of the second compressor 212 May include an increasing guide vane operation sequence.

The controller 270 performs a stop sequence for stopping the first chiller module 201 when the start sequence of the second chiller module 202 is completed, 201). Of course, it is also possible to stop the first chiller module 201 without performing the stop sequence.

On the other hand, when the second expected load factor and the second predicted rising rate are located in the fourth operating range while the second chiller module 202 is operating, the controller 270 determines whether the operation method is changed . In other words, since the capacity of the second chiller module can cope with the load, it is not necessary to change the operation method.

If the second expected load factor and the second predicted rising rate are located in the fifth operation range while the second chiller module 202 is operating, the controller 270 determines that the operation method needs to be changed . That is, since the capacity of the second chiller module 202 can not cope with the load, it is necessary to change the operation method.

Accordingly, the controller 270 further activates the first chiller module 201 while the second chiller module 202 is operating.

Meanwhile, when the second expected load factor and the second predicted rising rate are located in the fourth operation range while the first and second chiller modules 201 and 202 operate together, the controller 270) determines that the operation method needs to be changed. That is, since the capacity of the second chiller module 202 can correspond to the load, it is necessary to change the operation method. Accordingly, the controller 270 may stop the first chiller module 201.

When the second expected load factor and the second predicted rising rate are located in the second operation range while the second chiller module 202 is operating, the controller 270 determines that the operation method needs to be changed do. That is, since the capacity of the first chiller module 201 can correspond to the load, it is necessary to change the operation method. Accordingly, the controller 270 may stop the second chiller module 202 and operate the first chiller module 201.

If it is determined that the operation target is changed to the first chiller module 201 while the second chiller module 202 is operating, the opening of the guide vane of the second compressor 212 of the second chiller module 202 Can be reduced. When the opening degree of the guide vane of the second compressor 212 reaches the reference opening degree, the startup sequence of the first chiller module 201 is performed. The startup sequence of the first chiller module 201 is the same as the startup sequence of the second chiller module 201 described above.

When the startup sequence of the first chiller module 201 is completed, the first chiller module 201 operates normally, and after the stop sequence of the second chiller module 202 is performed, the second chiller module 202 ) Is stopped. Of course, it is also possible that the second chiller module 202 is stopped without performing the stop sequence.

According to the present invention, there is an advantage in that it is possible to effectively cope with a load by performing logarithmic control using a plurality of chiller modules having different capacities.

In addition, in the present invention, the operating method change judgment criterion at the time of increasing the expected load differs from the operating method change criterion at the time of the anticipated load reduction. This is to prevent frequent on / off repetition of the chiller module.

For example, when the judgment method of the operation method at the time of the increase in the expected load is the same as the judgment method of the operation method at the time of the increase in the expected load, that is, when the first load reduction reference line and the second load increase reference line are the same line in Fig. 2 < / RTI > expected load ratio and the second predicted rising rate are frequently changed at a position adjacent to the reference line, the first chiller module is turned off, the second chiller module is turned on, the second chiller module is turned off, In such a case, there may be a problem that the power consumption is increased and the load can not be stably responded to.

However, in the case of the present invention, frequent on / off of the chiller module is prevented because the operating method change judgment criterion at the time of increasing load is different from the operating condition change criterion at the time of decreasing the load. Therefore, the power consumption is reduced and the load can be stably There are advantages to be able to.

In the above embodiment, the two chiller modules constitute one set of chillers. Alternatively, even when three or more chiller modules constitute one set of chillers, the idea of the present invention can be applied equally.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. Furthermore, the terms "comprises", "comprising", or "having" described above mean that a component can be implanted unless otherwise specifically stated, But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

201: first chiller module 202: second chiller module
210: first compressor 212: second compressor
220: first condenser 222: second condenser
240: first evaporator 242: second condenser
270: Controller

Claims (13)

A plurality of chiller modules each comprising a compressor, a condenser and an evaporator; And
And a controller for controlling the plurality of chiller modules,
The controller determines an expected load, determines a chiller module to operate among a plurality of chiller modules based on the determined expected load, activates the determined chiller module,
The controller activating some or all of the plurality of chiller modules based on the expected load,
The controller determines the expected load based on an expected load factor and an expected load factor,
The predicted load factor is determined based on the temperature of the cold water flowing into the evaporator, the target cold water outlet temperature and the cold water temperature difference,
Wherein the predicted rising rate is determined based on a temperature of the cooling water flowing into the condenser, a target cold water outflow temperature, a cooling water temperature difference, a rated cooling water outflow temperature and a rated cold water outflow temperature. The method according to claim 1,
Wherein the plurality of chiller modules have different capacities. delete delete The method according to claim 1,
Wherein the plurality of chiller modules includes a first chiller module and a second chiller module having a capacity larger than that of the first chiller module,
If it is determined that the operation method should be changed during the operation of the first chiller module,
The controller stops the first chiller module and activates the second chiller module, or operates the first and second chiller modules together. The method according to claim 1,
Wherein the plurality of chiller modules includes a first chiller module and a second chiller module having a capacity larger than that of the first chiller module,
If it is determined that the operation method should be changed during the operation of the second chiller module,
Wherein the controller stops the second chiller module and activates the first chiller module, or operates the first and second chiller modules together. The method according to claim 5 or 6,
The judgment criteria for judging whether or not the operation change is necessary includes a judgment criterion when the expected load is increased and a judgment criterion when the expected load is reduced. The method according to claim 5 or 6,
The controller determines whether or not an operation change is required based on the expected load factor and the predicted rate of change,
The predicted load factor is determined based on the temperature of the cold water discharged from the evaporator, the target cold water outlet temperature and the cold water rated temperature difference,
Wherein the predicted rate of rise is determined on the basis of the temperature of the cooling water flowing into the condenser, the target cold water outflow temperature, the cooling water rated temperature difference, the rated cooling water outflow temperature and the rated cold water outflow temperature. 6. The method of claim 5,
If it is determined that the operation object is to be changed by the second chiller module during the operation of the first chiller module,
Wherein the controller performs the startup sequence of the second chiller module and stops the operation of the first chiller module after the start sequence of the second chiller module is completed. The method according to claim 6,
If it is determined that the operation object is to be changed by the first chiller module during the operation of the second chiller module,
Wherein the controller reduces the opening of the guide vane of the compressor of the second chiller module and performs the startup sequence of the first chiller module when the opening degree of the guide vane reaches the reference opening degree. 11. The method of claim 10,
Wherein the controller stops the operation of the second chiller module after the startup sequence of the first chiller module is completed. A first chiller module having a first compressor, a first condenser, and a first evaporator;
A second chiller module having a capacity greater than that of the first chiller module and having a second compressor, a second condenser, and a second evaporator; And
And a controller for controlling the first chiller module and the second chiller module,
Wherein the controller determines a chiller module to operate among the first and second chiller modules when the operation start command is input,
The controller determines a Chiller module to operate based on the expected load,
The controller determines the expected load based on an expected load factor and an expected load factor,
The predicted load factor is determined based on the temperature of the cold water flowing into the first and second evaporators, the target cold water outlet temperature and the cold water rated temperature difference,
Wherein the predicted rising rate is determined based on the temperature of the cooling water flowing into the first and second condensers, the target cold water outflow temperature, the cooling water temperature difference, the rated cooling water outflow temperature and the rated cold water outflow temperature. delete

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