Turbo refrigerator, refrigerator control device, method for controlling turbo refrigerator, and program

Abstract

A turbo refrigerator is provided with: a turbo compressor that compresses a refrigerant gas; a blade capable of adjusting the flow rate of the refrigerant gas sucked in by the turbo compressor; a condenser that condenses the refrigerant gas compressed by the turbo compressor by dissipating heat through heat exchange; an expansion valve that expands the liquid refrigerant extracted from the condenser; an evaporator that evaporates the liquid refrigerant expanded by the expansion valve by heat exchange by absorbing heat; and a refrigerator control device provided with: an acquisition unit for acquiring at least the state quantity of the refrigerant gas when the turbo refrigerator is started; an opening degree determination unit that determines the opening degree of the blade on the basis of the acquired state quantity; and an opening degree control unit that controls the opening degree of the blade on the basis of the determined opening degree.

Description

Technical Field

[0001] The present invention relates to a turbo refrigerator, a refrigerator control device, a control method for a turbo refrigerator, and a program. This application claims priority based on Japanese Patent Application No. 2022-144367 filed in Japan on September 12, 2022, and the contents thereof are incorporated herein by reference. Background Art

[0002] Patent document 1 discloses a turbo refrigerator, which includes a turbo compressor for compressing refrigerant gas and a suction capacity control unit for controlling the capacity of the refrigerant gas passing through the turbo compressor. In the turbo refrigerator disclosed in patent document 1, when the turbo compressor is started, the suction capacity control unit is set to a target opening. The target opening of the suction capacity control unit is set for the purpose of suppressing oil rise by causing foaming caused by the refrigerant dissolved in the lubricating oil in the oil tank of the turbo compressor when the turbo refrigerator is started.

[0003] Previous technical literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-186030 Summary of the invention

[0006] Technical issues to be solved by the invention

[0007] In a turbo refrigerator, when the load caused by the refrigerant gas sucked into the turbo compressor is large at startup, the starting current and startup time of the electric motor driving the turbo compressor increase. Therefore, when the turbo refrigerator is started, the opening of the blades at the refrigerant gas inlet provided in the turbo compressor is reduced to limit the suction flow rate of the refrigerant gas.

[0008] However, the flow rate of the refrigerant gas sucked by the turbo compressor at startup can vary according to the refrigerant state such as the refrigerant density at startup. Therefore, if the initially set blade opening is maintained, there is a problem that the turbo compressor does not match the refrigerant gas state at the startup of the turbo compressor, resulting in poor startup of the turbo compressor.

[0009] The turbo refrigerator described in Patent Document 1 does not solve such a problem.

[0010] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a turbo refrigerator, a refrigerator control device, a turbo refrigerator control method, and a program that can improve the startability regardless of the state of the refrigerant gas at the time of startup.

[0011] Means for solving technical problems

[0012] In order to solve the above-mentioned problems, the turbo refrigerator involved in the present invention comprises: a turbo compressor, which compresses refrigerant gas; blades, which can adjust the flow rate of the refrigerant gas sucked by the turbo compressor; a condenser, which dissipates heat and condenses the refrigerant gas compressed by the turbo compressor through heat exchange; an expansion valve, which expands the liquid refrigerant drawn out from the condenser; an evaporator, which absorbs heat and evaporates the liquid refrigerant expanded by the expansion valve through heat exchange; and a refrigerator control device, the refrigerator control device comprising: an acquisition unit, which acquires at least the state quantity of the refrigerant gas when the turbo refrigerator is started; an opening determination unit, which determines the opening of the blade based on the acquired state quantity; and an opening control unit, which controls the opening of the blade based on the determined opening.

[0013] In the refrigerator control device of the turbo refrigerator involved in the present invention, the turbo refrigerator comprises: a turbo compressor, which compresses refrigerant gas; a blade, which can adjust the flow rate of the refrigerant gas sucked by the turbo compressor; a condenser, which dissipates heat and condenses the refrigerant gas compressed by the turbo compressor through heat exchange; an expansion valve, which expands the liquid refrigerant drawn out from the condenser; and an evaporator, which absorbs heat and evaporates the liquid refrigerant expanded by the expansion valve through heat exchange. The refrigerator control device comprises: an acquisition unit, which acquires at least the state quantity of the refrigerant gas when the turbo refrigerator is started; an opening determination unit, which determines the opening of the blade based on the acquired state quantity; and an opening control unit, which controls the opening of the blade based on the determined opening.

[0014] In the control method of the turbo refrigerator involved in the present invention, the turbo refrigerator comprises: a turbo compressor, which compresses refrigerant gas; a blade, which can adjust the flow rate of the refrigerant gas sucked by the turbo compressor; a condenser, which dissipates heat and condenses the refrigerant gas compressed by the turbo compressor through heat exchange; an expansion valve, which expands the liquid refrigerant drawn out from the condenser; and an evaporator, which absorbs heat and evaporates the liquid refrigerant expanded by the expansion valve through heat exchange. The control method includes the following steps: when the turbo refrigerator is started, at least the state quantity of the refrigerant gas is obtained; based on the obtained state quantity, the opening degree of the blade is determined; and based on the determined opening degree, the opening degree of the blade is controlled.

[0015] The program involved in the present invention enables a computer of a turbo refrigerator to execute the following steps: when the turbo refrigerator is started, at least a state quantity of the refrigerant gas is obtained; based on the obtained state quantity, the opening of the blade is determined; and based on the determined opening, the opening of the blade is controlled, and the turbo refrigerator comprises: a turbo compressor, which compresses the refrigerant gas; blades, which can adjust the flow rate of the refrigerant gas sucked into the turbo compressor; a condenser, which dissipates heat and condenses the refrigerant gas compressed by the turbo compressor through heat exchange; an expansion valve, which expands the liquid refrigerant drawn out from the condenser; and an evaporator, which absorbs heat and evaporates the liquid refrigerant expanded by the expansion valve through heat exchange.

[0016] Effects of the Invention

[0017] According to the turbo refrigerator, refrigerator control device, turbo refrigerator control method, and program of the present invention, it is possible to improve the startability regardless of the state of the refrigerant gas at the time of startup. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a diagram showing the overall structure of a turbo refrigerator according to an embodiment of the present invention.

[0019] Figure 2 1 is a block diagram showing the functional structure of a refrigerator control device for the turbo refrigerator.

[0020] Figure 3 This is a flowchart showing the steps of a method for controlling a turbo refrigerator according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] Hereinafter, a mode for implementing a turbo refrigerator, a refrigerator control device, a turbo refrigerator control method, and a program according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments.

[0022] (Overall structure of turbo refrigerator)

[0023] like Figure 1 As shown, the turbo refrigerator 1 mainly includes a turbo compressor 3 for compressing refrigerant gas, a condenser 5 , an expansion valve 7 , an evaporator 9 , and a refrigerator control device 100 .

[0024] The condenser 5 condenses the high-temperature and high-pressure gas refrigerant compressed by the turbo compressor 3. The condenser 5 condenses the refrigerant gas compressed by the turbo compressor 3 by heat exchange with cooling water. The condenser 5 may be a shell and tube type or plate type heat exchanger.

[0025] The expansion valve 7 expands the liquid refrigerant condensed in the condenser 5. The expansion valve 7 is, for example, an electric type, and the opening degree thereof is arbitrarily set by the refrigerator control device 100.

[0026] The evaporator 9 evaporates the liquid refrigerant expanded by the expansion valve 7. The evaporator 9 absorbs heat from the liquid refrigerant expanded by the expansion valve 7 and evaporates the liquid refrigerant by heat exchange with water or the like to be cooled. As the evaporator 9, a shell and tube type or plate type heat exchanger can be exemplified.

[0027] The turbo compressor 3 is a centrifugal compressor, and is driven by an electric motor 11 whose rotation speed is controlled by an inverter (not shown). The output of the inverter is controlled by a refrigerator control device 100. The turbo compressor 3 has an impeller 3a that rotates around a rotating shaft 3b. The rotational power is transmitted from the electric motor 11 to the rotating shaft 3b via a speed increaser 15. The rotating shaft 3b is supported by a bearing 3c so as to be rotatable around the central axis of the rotating shaft 3b. The turbo compressor 3 compresses the refrigerant gas sucked into the casing (not shown) of the turbo compressor 3 by the impeller 3a that rotates around the rotating shaft 3b, and ejects it to the condenser 5.

[0028] The turbo compressor 3 may be a type not including the speed increaser 15 (for example, a motor direct-coupled type).

[0029] A vane 13 (so-called inlet guide vane: IGV) is provided at the refrigerant suction port of the turbo compressor 3. The vane 13 can adjust the opening of the refrigerant suction port by means of an opening adjustment mechanism 17 including a motor or the like. By adjusting the opening of the vane 13, the flow rate of the refrigerant sucked into the turbo compressor 3 at the refrigerant suction port is adjusted.

[0030] The refrigerator control device 100 controls the operation of each part of the centrifugal refrigerator 1. In the present embodiment, the refrigerator control device 100 controls the opening degree of the blade 13 by controlling the opening degree adjustment mechanism 17 when the centrifugal refrigerator 1 is started.

[0031] A pressure sensor 120 is provided on the outlet side of the evaporator 9. The pressure sensor 120 detects the pressure of the refrigerant gas on the outlet side of the evaporator 9. The pressure sensor 120 outputs the detection result of the pressure of the refrigerant gas to the refrigerator control device 100.

[0032] Figure 2 1 is a block diagram showing the functional structure of a refrigerator control device for the turbo refrigerator.

[0033] The refrigerator control device 100 can be constructed using a computer and hardware including a peripheral circuit or peripheral device of the computer, wherein the computer includes a CPU (Central Processing Unit), a volatile and non-volatile storage device, an input / output device, a communication device, etc. Figure 2 As shown, the refrigerator control device 100 includes an acquisition unit 101, an opening degree determination unit 102, an opening degree control unit 103, and a storage unit 105 as a functional structure composed of a combination of hardware and software such as a program executed by a computer.

[0034] The acquisition unit 101 acquires information necessary for determining the opening degree of the vane 13 required when the turbo refrigerator 1 is started (hereinafter referred to as the required vane opening degree).

[0035] The acquisition unit 101 acquires the device information of the turbo compressor 3. Examples of the device information of the turbo compressor 3 include the model of the turbo compressor 3, the type of refrigerant used, and the shape of the blade 13.

[0036] The device information of the turbo compressor 3 may be input to the refrigerator control device 100 from the outside by an operator, or may be acquired from an external storage device or the like storing the device information of the turbo compressor 3 .

[0037] Furthermore, the acquisition unit 101 acquires the state information of the turbo refrigerator 1 when it is started (just before it is started) as the required information for determining the required blade opening. The acquisition unit 101 acquires at least the state quantity of the refrigerant gas as the state information. In the present embodiment, the acquisition unit 101 acquires the pressure of the refrigerant gas sucked by the turbo compressor 3 as the state quantity of the refrigerant gas. The acquisition unit 101 acquires the detection result of the pressure of the refrigerant gas at the outlet side of the evaporator 9 detected by the pressure sensor 120 as the pressure of the refrigerant gas sucked by the turbo compressor 3. The acquisition unit 101 can acquire the temperature of the refrigerant gas sucked by the turbo compressor 3 as the state quantity of the refrigerant gas.

[0038] In addition, the acquisition unit 101 acquires the operating speed of the turbo compressor 3 when the turbo refrigerator 1 is in stable operation as state information. The operating speed may be input to the refrigerator control device 100 from the outside by an operator, or may be set in advance in the refrigerator control device 100 from the outside when the turbo refrigerator 1 is started, and the value of the operating speed stored in the storage unit 105 is acquired.

[0039] The storage unit 105 stores the device information, status information, and the like acquired by the acquisition unit 101 .

[0040] The opening degree determination unit 102 determines the required blade opening degree of the blade 13 when starting the turbo refrigerator 1 based on the device information and the state information acquired by the acquisition unit 101 .

[0041] The opening control unit 103 controls the opening adjustment mechanism 17 based on the required blade opening determined by the opening determination unit 102 , thereby controlling the opening of the blade 13 .

[0042] (Control method of turbo refrigerator)

[0043] Figure 3 This is a flowchart showing the steps of a method for controlling a turbo refrigerator according to an embodiment of the present invention.

[0044] like Figure 3 As shown, when the turbo refrigerator 1 is started, first, the acquisition unit 101 acquires the device information of the turbo compressor 3 (step S10). The acquisition unit 101 reads and acquires the model of the turbo compressor 3, the type of refrigerant used, the shape of the blade 13, etc. as the device information of the turbo compressor 3 from the storage unit 105. More specifically, the acquisition unit 101 acquires the allowable front-to-back pressure difference ΔPsb of the blade 13 that is preset based on the shape of the blade 13, etc. The allowable front-to-back pressure difference ΔPsb of the blade 13 refers to the preset allowable value of the pressure difference between the upstream side and the downstream side of the refrigerant gas in the suction direction of the blade 13. In addition, the acquisition unit 101 acquires the correction value K of the preset allowable front-to-back pressure difference ΔPsb according to the model of the turbo compressor 3. In addition, the acquisition unit 101 acquires a function (calculation formula) that indicates the correlation between the pressure (or temperature) of the refrigerant and the density ρ of the refrigerant that is preset for each type of refrigerant used. This function is obtained by acquiring information on (saturated) pressure-(saturated) temperature-density of the refrigerant from a database of physical property values ​​of the refrigerant (for example, REFPROP based on the National Institute of Standards and Technology (NIST) of the United States), and establishing an approximate formula from the data.

[0045] Next, the acquisition unit 101 acquires the state information of the turbo refrigerator 1 when it is started (immediately before it is started) (step S20). The acquisition unit 101 acquires the detection result of the pressure of the refrigerant gas at the outlet side of the evaporator 9 detected by the pressure sensor 120 as the state information. In addition, the acquisition unit 101 acquires the operating speed of the turbo compressor 3 when the turbo refrigerator 1 is in stable operation as the state information.

[0046] Next, the opening determination unit 102 determines the required vane opening as the opening of the vane 13 when starting the turbo compressor 3 based on the device information acquired in step S10 and the state information acquired in step S20 (step S30). In the present embodiment, step S30 includes steps S31 to S36 shown below.

[0047] First, the opening degree determination unit 102 calculates the required vane opening degree of the vane 13 required when starting the turbo compressor 3 (step S31 ).

[0048] To this end, the opening degree determination unit 102 calculates the density ρ of the refrigerant immediately before starting the turbo compressor 3 using a preset function based on the type of refrigerant used in the turbo refrigerator 1 obtained in step S10 and the detection result of the refrigerant gas pressure obtained in step S20 .

[0049] Then, the opening degree determination unit 102 calculates the blade opening degree increase / decrease coefficient XB according to the following equation (1) using the allowable front-rear pressure difference ΔPsb acquired in step S10 , the correction value K, and the operating speed of the turbo compressor 3 acquired in step S20 .

[0050] XB=(ΔPsb×K) / f(ρ)×XN)…(1)

[0051] In addition, f(ρ) is a reference estimated pressure difference of the blade 13 when the turbo compressor 3 is started, which is calculated based on the density of the refrigerant gas and according to a predetermined function. The equipment information of the turbo compressor 3 read from the storage unit 105 includes the difference between each model (model difference). The reference estimated pressure difference is used to include the model difference and is used as a control base (base) for each model of the turbo compressor 3. In addition, XN is an increase or decrease coefficient of the Mach number determined according to the rotation speed of the turbo compressor 3. The larger the Mach number (rotation speed of the turbo compressor 3), the more refrigerant flows into the turbo compressor 3, and the load on the blade 13 increases. The increase or decrease coefficient of the Mach number is used to take into account the load change on the blade 13 corresponding to the Mach number.

[0052] The opening determination unit 102 calculates the required blade opening of the blade 13 required when starting the turbo compressor 3, based on the blade opening increase / decrease coefficient XB calculated by the formula (1), by using a predetermined function f(XB). Here, if the opening (=angle) of the blade 13 changes, the force (resistance for swinging the blade 13) from the refrigerant (fluid) changes accordingly. Therefore, it is preferable to calculate the required blade opening of the blade 13 in consideration of the blade opening increase / decrease coefficient XB.

[0053] Thus, the higher the pressure of the refrigerant gas obtained in step S20 is, the larger the required blade opening of the blade 13 calculated in step S31 is. Also, the higher the operating speed of the turbo compressor 3 obtained in step S20 is, the larger the required blade opening of the blade 13 is.

[0054] Next, the opening determination unit 102 confirms whether the required blade opening of the blade 13 calculated in step S31 falls within the preset opening range of the blade 13. The opening determination unit 102 determines the required blade opening of the blade 13 so that it falls between the preset minimum opening setting value and the maximum opening setting value of the blade 13.

[0055] First, the opening degree determination unit 102 determines whether the required blade opening degree of the blade 13 calculated in step S31 is equal to or greater than a preset minimum opening degree setting value (step S32 ).

[0056] In step S32, when the required blade opening is not greater than the minimum opening setting value (step S32: No), the opening determination unit 102 updates the required blade opening of the blade 13 when starting the turbo compressor 3 to the minimum opening setting value (step S33) for determination. This prevents the actual opening of the blade 13 from becoming too small when starting the turbo compressor 3.

[0057] Then, in step S32 , when the required blade opening is equal to or greater than the minimum opening setting value (step S32 : Yes), the opening determination unit 102 determines whether the required blade opening of the blade 13 calculated in step S31 is equal to or less than a preset maximum opening setting value (step S34 ).

[0058] In step S34, when the required blade opening is not less than the maximum opening setting value (step S34: No), the opening determination unit 102 updates the required blade opening of the blade 13 when starting the turbo compressor 3 to the maximum opening setting value and determines it (step S35). This prevents the actual opening of the blade 13 from becoming too large when starting the turbo compressor 3.

[0059] Furthermore, in step S34, when the required blade opening is less than the maximum opening setting value (step S34: Yes), the opening determination unit 102 directly determines the required blade opening of the blade 13 calculated in step S31 as the required blade opening of the blade 13 when starting the turbo compressor 3 (step S36).

[0060] The opening control unit 103 controls the opening adjustment mechanism 17 based on the required opening of the vane determined as described above, thereby adjusting the actual opening of the vane 13. Thereafter, the refrigerator control device 100 starts the turbo compressor 3.

[0061] After starting the turbo compressor 3 , the refrigerator control device 100 adjusts the opening degree of the vane 13 according to the operating rotation speed of the turbo compressor 3 .

[0062] (Effect)

[0063] In the turbo refrigerator 1, refrigerator control device 100, turbo refrigerator control method and program of the above-mentioned structure, at least the state quantity of the refrigerant gas is acquired when the turbo refrigerator 1 is started, and the opening degree of the blade 13 is controlled according to the acquired state quantity. Thus, at the startup of the turbo refrigerator 1, the opening degree of the blade 13 can be made to correspond to the state of the refrigerant gas at that time. Therefore, regardless of the state of the refrigerant gas at the startup, the startup performance of the turbo refrigerator 1 can be improved.

[0064] Furthermore, as a state quantity of the refrigerant gas, the density of the refrigerant gas can be calculated by acquiring the pressure of the refrigerant gas sucked into the turbo compressor 3. Thus, the opening degree of the vane 13 can be controlled according to the density of the refrigerant gas when the turbo refrigerator 1 is started.

[0065] Furthermore, by detecting the pressure of the refrigerant gas at the outlet side of the evaporator 9 by the pressure sensor 120 , the pressure of the refrigerant gas sucked into the turbo compressor 3 can be easily acquired as the state quantity of the refrigerant gas.

[0066] Furthermore, the pressure difference caused by the refrigerant gas acting on the blade 13 can be obtained based on the pressure of the refrigerant gas sucked by the turbo compressor 3 and the operating speed of the turbo compressor 3 when the turbo refrigerator 1 is in stable operation. By calculating the opening of the blade 13 based on the obtained pressure difference, it is possible to suppress the opening adjustment of the blade 13 from being hindered by the pressure difference acting on the blade 13, and at the same time, the opening of the blade 13 can be appropriately adjusted.

[0067] Furthermore, by determining the opening degree of the blade 13 so as to fall between the minimum opening degree setting value and the maximum opening degree setting value, the opening degree of the blade 13 can be appropriately adjusted.

[0068] (Other Implementations)

[0069] As mentioned above, although the embodiment of the present invention is described in detail with reference to the drawings, the specific structure is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present invention are also included.

[0070] Furthermore, in the above-described embodiment, the steps of the method for controlling the centrifugal chiller 1 are exemplified, but the order thereof can be changed as appropriate.

[0071] Furthermore, part or all of the program executed by the computer in the above-mentioned embodiments may be distributed via a computer-readable storage medium or a communication line.

[0072] <Note>

[0073] The centrifugal chiller 1 , the chiller control device 100 , the control method and the program of the centrifugal chiller 1 described in the embodiment can be understood, for example, as follows.

[0074] (1) A turbo refrigerator 1 according to a first embodiment includes: a turbo compressor 3 for compressing a refrigerant gas; a vane 13 for adjusting a flow rate of the refrigerant gas sucked into the turbo compressor 3; a condenser 5 for condensing the refrigerant gas compressed by the turbo compressor 3 by dissipating heat; an expansion valve 7 for expanding the liquid refrigerant drawn out from the condenser 5; an evaporator 9 for evaporating the liquid refrigerant expanded by the expansion valve 7 by absorbing heat; and a refrigerator control device 100, wherein the refrigerator control device 100 includes: an acquisition unit 101 for acquiring at least a state quantity of the refrigerant gas when the turbo refrigerator 1 is started; an opening determination unit 102 for determining an opening degree of the vane 13 based on the acquired state quantity; and an opening control unit 103 for controlling the opening degree of the vane 13 based on the determined opening degree.

[0075] The turbo refrigerator 1 acquires at least the state quantity of the refrigerant gas when the turbo refrigerator 1 is started, and controls the opening degree of the vane 13 according to the acquired state quantity. Thus, when the turbo refrigerator 1 is started, the opening degree of the vane 13 can be made to correspond to the state of the refrigerant gas at that time. Therefore, the startability of the turbo refrigerator 1 can be improved regardless of the state of the refrigerant gas at the time of startup.

[0076] (2) The turbo refrigerator 1 according to the second aspect is the turbo refrigerator 1 according to (1), wherein the acquisition unit 101 acquires at least one of a pressure and a temperature of the refrigerant gas sucked into the turbo compressor 3 as the state quantity of the refrigerant gas.

[0077] Thus, by acquiring at least one of the pressure and temperature of the refrigerant gas sucked into the turbo compressor 3 as the state quantity of the refrigerant gas, the opening degree of the vane 13 can be controlled according to the state of the refrigerant gas when the turbo refrigerator 1 is started.

[0078] (3) The turbo refrigerator 1 involved in the third embodiment is the turbo refrigerator 1 of (2), wherein the turbo refrigerator 1 includes: a pressure sensor 120 for detecting the pressure of the refrigerant gas at the outlet side of the evaporator 9, and the acquisition unit acquires 101 the pressure of the refrigerant gas detected by the pressure sensor 120 as the state quantity of the refrigerant gas.

[0079] Thus, by detecting the pressure of the refrigerant gas at the outlet side of the evaporator 9 by the pressure sensor 120 , the pressure of the refrigerant gas sucked into the turbo compressor 3 can be easily acquired as the state quantity of the refrigerant gas.

[0080] (4) The turbo refrigerator 1 involved in the fourth embodiment is the turbo refrigerator 1 of (2) or (3), wherein the acquisition unit 101 acquires the operating speed of the turbo compressor 3 when the turbo refrigerator 1 is in stable operation, and the opening determination unit 102 calculates the opening of the blade 13 based on the pressure difference between the upstream side and the downstream side of the refrigerant gas in the suction direction of the blade 13.

[0081] Thus, the pressure difference between the upstream side and the downstream side of the refrigerant gas in the suction direction of the blade 13 can be obtained based on at least one of the pressure and temperature of the refrigerant gas sucked by the turbo compressor 3 and the operating speed of the turbo compressor 3 when the turbo refrigerator 1 is in stable operation. By calculating the opening of the blade 13 based on the obtained pressure difference, it is possible to suppress the adjustment of the opening of the blade 13 from being hindered by the pressure difference acting on the blade 13, and at the same time, the opening of the blade 13 can be appropriately adjusted.

[0082] (5) The turbo refrigerator 1 according to the fifth aspect is the turbo refrigerator 1 according to any one of (1) to (4), wherein the opening degree determination unit 102 determines the opening degree of the blade 13 so as to fall between a preset minimum setting value and a preset maximum setting value of the opening degree of the blade 13 .

[0083] Thus, the opening degree of the blade 13 is determined so as to fall between the minimum setting value and the maximum setting value, thereby making it possible to appropriately adjust the opening degree of the blade 13 .

[0084] (6) A refrigerator control device 100 for a turbo refrigerator 1 according to a sixth embodiment, the turbo refrigerator 1 comprising: a turbo compressor 3 for compressing a refrigerant gas; a vane 13 for adjusting the flow rate of the refrigerant gas sucked into the turbo compressor 3; a condenser 5 for condensing the refrigerant gas compressed by the turbo compressor 3 by dissipating heat; an expansion valve 7 for expanding the liquid refrigerant drawn out from the condenser 5; and an evaporator 9 for evaporating the liquid refrigerant expanded by the expansion valve 7 by absorbing heat, the refrigerator control device 100 comprising: an acquisition unit 101 for acquiring at least a state quantity of the refrigerant gas when the turbo refrigerator 1 is started; an opening determination unit 102 for determining the opening degree of the vane 13 based on the acquired state quantity; and an opening control unit 103 for controlling the opening degree of the vane 13 based on the determined opening degree.

[0085] Thus, the startability of the turbo refrigerator 1 can be improved regardless of the state of the refrigerant gas at the time of startup.

[0086] (7) A control method for a turbo refrigerator 1 according to a seventh aspect, the turbo refrigerator 1 comprising: a turbo compressor 3 for compressing a refrigerant gas; a vane 13 for adjusting the flow rate of the refrigerant gas sucked into the turbo compressor 3; a condenser 5 for condensing the refrigerant gas compressed by the turbo compressor 3 by dissipating heat; an expansion valve 7 for expanding the liquid refrigerant drawn out from the condenser 5; and an evaporator 9 for evaporating the liquid refrigerant expanded by the expansion valve 7 by absorbing heat, the control method comprising the following steps: obtaining at least a state quantity of the refrigerant gas when the turbo refrigerator 1 is started; determining the opening degree of the vane 13 based on the obtained state quantity; and controlling the opening degree of the vane 13 based on the determined opening degree.

[0087] Thus, the startability of the turbo refrigerator 1 can be improved regardless of the state of the refrigerant gas at the time of startup.

[0088] (8) The program involved in the eighth mode causes a computer provided in a turbo refrigerator 1 to execute the following steps: when the turbo refrigerator 1 is started, at least a state quantity of the refrigerant gas is obtained; based on the obtained state quantity, the opening degree of the blade 13 is determined; and based on the determined opening degree, the opening degree of the blade 13 is controlled, wherein the turbo refrigerator comprises: a turbo compressor 3 for compressing the refrigerant gas; a blade 13 for adjusting the flow rate of the refrigerant gas sucked into the turbo compressor 3; a condenser 5 for condensing the refrigerant gas compressed by the turbo compressor 3 by dissipating heat through heat exchange; an expansion valve 7 for expanding the liquid refrigerant drawn out from the condenser 5; and an evaporator 9 for evaporating the liquid refrigerant expanded by the expansion valve 7 by absorbing heat through heat exchange.

[0089] Thus, the startability of the turbo refrigerator 1 can be improved regardless of the state of the refrigerant gas at the time of startup.

[0090] Industrial Applicability

[0091] According to the turbo refrigerator, refrigerator control device, turbo refrigerator control method, and program of the present invention, it is possible to improve the startability regardless of the state of the refrigerant gas at the time of startup.

[0092] Explanation of symbols

[0093] 1- turbo refrigerator, 3- turbo compressor, 3a- impeller, 3b- rotating shaft, 3c- bearing, 5- condenser, 7- expansion valve, 9- evaporator, 11- motor, 13- blades, 15- speed increaser, 17- opening adjustment mechanism, 100- refrigerator control device, 101- acquisition unit, 102- opening determination unit, 103- opening control unit, 105- storage unit, 120- pressure sensor.

Claims

1. A turbo refrigerator, comprising: turbo compressor, compressing refrigerant gas; a blade capable of adjusting the flow rate of the refrigerant gas sucked into the turbo compressor; A condenser for condensing the refrigerant gas compressed by the turbo compressor by dissipating heat through heat exchange; an expansion valve for expanding the liquid refrigerant drawn from the condenser; an evaporator for absorbing heat and evaporating the liquid refrigerant expanded by the expansion valve through heat exchange; and Refrigerator control device, The refrigerator control device comprises: an acquisition unit, which acquires at least the state quantity of the refrigerant gas when the turbo refrigerator is started; an opening determination unit, which determines the opening of the blade according to the acquired state quantity; and The opening control unit controls the opening of the blade according to the determined opening.

2. The turbo refrigerator according to claim 1, wherein: The acquisition unit acquires at least one of a pressure and a temperature of the refrigerant gas sucked into the turbo compressor as a state quantity of the refrigerant gas.

3. The turbo refrigerator according to claim 2, comprising: a pressure sensor detecting the pressure of the refrigerant gas at the outlet side of the evaporator, The acquisition unit acquires the pressure of the refrigerant gas detected by the pressure sensor as a state quantity of the refrigerant gas.

4. The turbo refrigerator according to claim 2 or 3, wherein: The acquisition unit acquires the operating speed of the turbo compressor when the turbo refrigerator is in stable operation. The opening degree determination unit calculates the opening degree of the vane based on a pressure difference between an upstream side and a downstream side of the vane in a suction direction of the refrigerant gas.

5. The turbo refrigerator according to claim 1 or 2, wherein: The opening degree determination unit determines the opening degree of the blade so as to fall between a preset minimum opening degree setting value and a preset maximum opening degree setting value of the blade.

6. A refrigerator control device for a turbo refrigerator, the turbo refrigerator comprising: turbo compressor, compressing refrigerant gas; a blade capable of adjusting the flow rate of the refrigerant gas sucked into the turbo compressor; A condenser for condensing the refrigerant gas compressed by the turbo compressor by dissipating heat through heat exchange; an expansion valve for expanding the liquid refrigerant drawn from the condenser; and The evaporator absorbs heat and evaporates the liquid refrigerant expanded by the expansion valve through heat exchange. The refrigerator control device comprises: an acquisition unit, which acquires at least a state quantity of the refrigerant gas when the turbo refrigerator is started; an opening determination unit, which determines the opening of the blade according to the acquired state quantity; and The opening control unit controls the opening of the blade according to the determined opening.

7. A control method for a turbo refrigerator, the turbo refrigerator comprising: turbo compressor, compressing refrigerant gas; a blade capable of adjusting the flow rate of the refrigerant gas sucked into the turbo compressor; A condenser for condensing the refrigerant gas compressed by the turbo compressor by dissipating heat through heat exchange; an expansion valve for expanding the liquid refrigerant drawn from the condenser; and The evaporator absorbs heat and evaporates the liquid refrigerant expanded by the expansion valve through heat exchange. The control method comprises the following steps: When the turbo refrigerator is started, at least the state quantity of the refrigerant gas is obtained; Determining the opening of the blade according to the acquired state quantity; and The opening degree of the blade is controlled according to the determined opening degree.

8. A program for causing a computer provided in a turbo refrigerator to execute the following steps: When the turbo refrigerator is started, at least a state quantity of the refrigerant gas is obtained; Determining the opening of the blade according to the acquired state quantity; and According to the determined opening, the opening of the blade is controlled, The turbo refrigerator comprises: a turbo compressor for compressing the refrigerant gas; a blade capable of adjusting the flow rate of the refrigerant gas sucked into the turbo compressor; A condenser for condensing the refrigerant gas compressed by the turbo compressor by dissipating heat through heat exchange; an expansion valve for expanding the liquid refrigerant drawn from the condenser; and The evaporator absorbs heat and evaporates the liquid refrigerant expanded by the expansion valve through heat exchange.

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