JP2004125225A - Stirling cold heat supply system and its operation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten pulldown time when starting a Stirling cold heat supply system 1. <P>SOLUTION: This system is provided with a Stirling refrigerator unit 4 for generating cold heat by compressing-expanding operating gas, a heat carrying device 6 for carrying a secondary refrigerant to a cold heat using apparatus 3 by cooling the secondary refrigerant by the cold heat generated by the Stirling refrigerator unit 4 and a refrigerant chiller unit 8 having a compressor 71 for compressing a refrigerant, a condenser 72 for condensing the refrigerant by exchanging heat with outside air, a decompressor 74 for decompressing the refrigerant and an evaporator 75 for cooling a secondary refrigerant by exchanging heat between the refrigerant and the secondary refrigerant. At pulldown time, the refrigerant chiller unit 8 is operated, and the secondary refrigerant is cooled up to a prescribed temperature, and when reaching the prescribed temperature, operation of the refrigerant chiller unit 8 is stopped, and the Stirling refrigerator unit 4 is controlled so as to operate. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a Stirling cold heat supply system capable of supplying cold generated by using a Stirling refrigerator unit to cold heat utilization equipment, and an operation method thereof.
[0002]
[Prior art]
The Stirling refrigerator unit has features that it can be miniaturized, has a high coefficient of performance and refrigeration efficiency, and can generate a low temperature range. In addition, it is easy to replace chlorofluorocarbon (helium can be used) in recent global environmental problems. It has certain features.
[0003]
For this reason, freezers, refrigerators, commercial or home-use cold energy utilization equipment such as throw-in type coolers, low-temperature liquid circulators, low-temperature thermostats, thermostats, heat shock test equipment, freeze dryers, temperature characteristic test equipment, Utilization as a cold heat source in blood / cell storage devices, cold coolers, various measurement devices, and the like is being studied.
[0004]
FIG. 11 is a circuit diagram showing a schematic configuration of such a Stirling chiller supply system 100, which includes a Stirling refrigerator unit 110, a cooling water device 120 for processing waste heat of the Stirling refrigerator unit 110, a heat transfer device 130, and the like. (See Patent Documents 1 and 2).
[0005]
As shown in FIG. 12, such a Stirling refrigerator unit 110 makes the working gas (helium) in the compression space 113 formed between the compression piston 111 reciprocate in the compression cylinder 112 as shown in FIG. As the compression part 114 and the expansion piston 115 reciprocate in the expansion cylinder 116, the expansion part 118, the compression space 113 and the expansion space 117 expand the working gas in the expansion space 117 formed between them. And a heat storage section 119 provided in the gas flow path S for communicating
[0006]
Then, the motor 109 is driven and the crank mechanism 108 converts the rotational power into reciprocating power. The reciprocating power causes the compression piston 111 and the expansion piston 115 to reciprocate to compress / expand the working gas.
[0007]
The compressed working gas passes through the gas flow path S, accumulates heat in the heat storage unit 119 and moves to the expansion space 117, where it expands to generate cold heat (endothermic action).
[0008]
The cold heat cools the cold head 131 provided on the head of the expansion section 118. Since the secondary refrigerant circulates through the cold head 131, the secondary refrigerant is cooled and its temperature decreases.
[0009]
The working gas expanded in the expansion section 118 returns to the compression section 114 through the heat storage section 119, and one cycle ends.
[0010]
The expansion piston 115 moves with a phase advance of about 90 degrees with respect to the compression piston 111.
[0011]
The heat transfer device 130 has a secondary refrigerant pump 132 and the like that pressure-feeds the secondary refrigerant so that it can circulate in a secondary refrigerant circuit formed so as to connect the cold head 131 and the cold energy utilization device 101.
[0012]
By the way, when the working gas is compressed by the compression unit 114, the temperature rises. However, the temperature of the working gas moving to the expansion unit 118 via the heat storage unit 119 as it is rises, and the cooling heat generation efficiency decreases.
[0013]
Therefore, a cooling water device 120 (not shown in the seat 12) is provided around the gas flow path S from the compression section 114 to the heat storage section 119 to cool the working gas flowing therethrough. It has become.
[0014]
As shown in FIG. 11, the cooling water device 120 includes a working gas side heat exchanger (not shown) for exchanging heat between the working gas and the cooling water, a radiator 121 for exchanging heat between the cooling water and the atmosphere, and a working gas side heat exchanger. And a radiator 121 for circulating cooling water.
[0015]
As a result, the working gas is cooled, and the heat is radiated to the atmosphere, thereby improving the cold heat generation efficiency.
[0016]
[Patent Document 1]
JP 200-186618 A
[Patent Document 2]
JP 200-186519 A
[0017]
[Problems to be solved by the invention]
However, the above configuration has a problem that it takes a certain amount of time to activate the Stirling chilled heat supply system 100 to lower the secondary refrigerant to a desired temperature (for example, −80 ° C.) (hereinafter referred to as pull-down). is there.
[0018]
That is, the Stirling refrigerator unit 110 is a cycle in which a working gas such as helium is compressed, dissipated, expanded, and absorbs heat, unlike a refrigeration cycle in which normal compression, condensation, decompression, and evaporation are repeated. Although it has the generation capability, the temperature drop rate of the cold heat is not large in a unit time sense, and the time required for the secondary refrigerant to reach a desired temperature is lengthened depending on the magnitude of the cooling load of the secondary refrigerant.
[0019]
Therefore, it takes a certain amount of time to pull down the Stirling refrigerator unit 110, the heat transfer device 130, and the cold energy utilization device 101 to a desired temperature range.
[0020]
Needless to say, as shown in FIG. 13, it is possible to shorten the time required for pull-down by increasing the cold-heat supply capacity by using a plurality of Stirling refrigerator units 110, but in such a case, the cost is increased. There is a problem that causes.
[0021]
Therefore, the present invention provides a Stirling refrigeration supply system and a method for operating the sterling refrigeration unit, which have a simple and inexpensive configuration, can shorten the pull-down time, and can increase the refrigeration capacity of the Stirling refrigerator unit. The purpose is to:
[0022]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 includes a Stirling refrigerator unit that compresses and expands a working gas to generate cold heat, and cools a secondary refrigerant by cold generated by the Stirling refrigerator unit. In a Stirling cold heat supply system including a heat transfer device that transfers a secondary refrigerant to a cold heat utilization device, a compressor that compresses the refrigerant, and a refrigerant that is discharged from the compressor exchanges heat with the outside air or water. A refrigerant chiller unit including a condenser for condensing the refrigerant, a decompression device for decompressing the refrigerant from the condenser, and an evaporator for cooling a secondary refrigerant by an evaporating action of the refrigerant decompressed by the decompression device is provided. It is characterized by having.
[0023]
The invention according to claim 2 is characterized in that the working gas of the Stirling refrigerator unit is helium gas, and the refrigerant of the refrigerant chiller unit is R404A.
[0024]
According to a third aspect of the present invention, when starting the Stirling chilled heat supply system according to the first or second aspect, after operating the refrigerant chiller unit to cool the secondary refrigerant to a predetermined temperature, the Stirling refrigerator unit is operated. It is characterized by operating and stopping the operation of the refrigerant chiller unit.
[0025]
The invention according to claim 4 is characterized in that a period is provided for simultaneously operating the Stirling refrigerator unit and the refrigerant chiller unit.
[0026]
According to a fifth aspect of the present invention, when the operation of the Stirling cold heat supply system according to the first or second aspect is started, the secondary chiller unit is operated to simultaneously operate to a predetermined temperature to cool the secondary refrigerant, and Starting the operation of the Stirling refrigerator unit from a temperature appropriately higher than the predetermined temperature, simultaneously operating the refrigerant chiller unit and the Stirling refrigerator unit in this temperature range, and stopping the operation of the refrigerant chiller unit when the predetermined temperature is reached. And controlling only the Stirling refrigerator unit to operate.
[0027]
According to a sixth aspect of the present invention, when the Stirling chilled heat supply system according to the first aspect is started to operate, the refrigerant chiller unit and the Stirling refrigerator unit are simultaneously operated to a predetermined temperature to cool the secondary refrigerant, and When the temperature reaches the temperature, the operation of the refrigerant chiller unit is stopped, and control is performed such that only the Stirling refrigerator unit is operated.
[0028]
According to a seventh aspect of the present invention, there is provided a Stirling refrigerating unit that generates cold heat by compressing and expanding a working gas, and cools a secondary refrigerant by the cold generated by the Stirling refrigerating unit. In a Stirling cold heat supply system including a heat transfer device that conveys the refrigerant, a compressor that compresses the refrigerant, and a condenser that condenses the refrigerant by exchanging heat with the outside air or water of the refrigerant discharged from the compressor. A decompression device for decompressing the refrigerant from the condenser, an evaporator for cooling the secondary refrigerant by an evaporating action of the refrigerant decompressed by the decompression device, and a Stirling refrigeration by evaporating the refrigerant decompressed by the decompression device. A second evaporator for absorbing heat radiation from the heat exchanger unit, and a switching valve for switching whether the refrigerant from the condenser is effectively evaporated by the evaporator or effectively evaporated by the second evaporator. Characterized by comprising.
[0029]
The invention according to claim 8 is characterized in that the pressure reducing device for the evaporator is different from the pressure reducing device for the second evaporator.
[0030]
According to a ninth aspect of the present invention, when the Stirling cold heat supply system according to the seventh or eighth aspect is started to operate, the switching valve is switched so that the refrigerant condensed in the condenser is effectively evaporated in the evaporator. Operating the refrigerant chiller unit to cool the secondary refrigerant to a predetermined temperature, and then switching the switching valve so that the refrigerant condensed in the condenser is effectively evaporated in the second evaporator. How to operate the cold heat supply system.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram of a Stirling cooling / heating supply system 1 applied to the description of the first embodiment, and FIG. 2 is a diagram showing a configuration of the Stirling refrigerator unit.
[0032]
The Stirling cold heat supply system 1 includes one Stirling refrigerator unit 4 that generates cold heat, a cooling water device 5 that exchanges heat with working gas in the Stirling refrigerator unit 4 and radiates the heat, and a secondary refrigerant ( For example, HFE: a material capable of sufficiently transferring heat at a desired temperature of the secondary refrigerant such as hydrofluoroether) is circulated between the Stirling refrigerator unit 4 and the cold heat utilization equipment 3 so that the Stirling refrigeration is performed. Transport device 6 for supplying the cold generated by the cooling unit 4 to the cold utilization device 3, a control device 7 for controlling the entire Stirling cold / hot supply system 1 so as to supply the required amount of cold from the cold utilization device 3, pull-down The main component is a refrigerant chiller unit 8 for cooling the secondary refrigerant in order to reduce the time.
[0033]
As shown in FIG. 13, it is possible to increase the cold heat supply capacity by using a plurality of Stirling refrigerator units 4 and thereby shorten the pull-down time. In this case, however, an expensive Stirling refrigerator unit 4 is used. Since a plurality of such devices must be provided, the cost increases.
[0034]
Further, for example, in the case of a cold heat utilizing device 3 such as a low temperature prober used in a semiconductor facility, a large amount of cold heat during use is not required. If the pull-down time is shortened by using the refrigerator unit 4, surplus capacity is generated, and the economic efficiency is reduced.
[0035]
Therefore, in the present invention, as described later, a refrigerant chiller unit 8 having a compressor, a condenser, a decompression device, an evaporator, and the like is provided to shorten a pull-down time.
[0036]
As shown in FIG. 2, the Stirling refrigerator unit 4 is formed between the crank part 12 for converting the rotational power of the motor 11 into reciprocating power and the compression piston 14 by reciprocating in the compression cylinder 15. A compression section 17 for compressing the working gas in the compression space 16, an expansion section 21 for expanding the working gas in an expansion space 20 formed between the expansion piston 18 by reciprocating the expansion piston 18 in the expansion cylinder 19, and a compression. It has a heat storage section 22 and the like made of a metal mesh sheet or the like provided in a gas flow path S that connects the space 16 and the expansion space 20.
[0037]
In the Stirling refrigerator unit 4, the crank part 12 is housed in a crank housing 24 forming a crank chamber 23 and has a crank 26 connected to a motor shaft 25, a connecting rod 27 connected to the crank 26 at one end, and a connecting rod 27. The cross guide head 28 is connected to the other end of the cross guide head 27, and a cross guide liner 29 that restricts the movement direction of the cross guide head 28 in one direction.
[0038]
As a result, the rotational power of the motor 11 is converted into reciprocating power by the crank section 12, and the compression piston 14 and the expansion piston 18 reciprocate.
[0039]
The expansion piston 18 moves with the phase advanced by about 90 degrees with respect to the compression piston 14.
[0040]
The compression piston 14 and the expansion piston 18 are connected to a cross guide head 28 via a piston rod 30. One end of the compression piston 14 and the expansion piston 18 is firmly fixed to the piston rod 30, and the other end is tightly fixed to the fixed plate 36. A fixed oil seal bellows 37 is provided.
[0041]
The oil seal bellows 37 is a metal bellows that expands and contracts with the reciprocating movement of the piston rod 30, and hermetically partitions the space on the compression piston 14 and expansion piston 18 side and the space on the cross guide head 28 side.
[0042]
As a result, the oil 38 for lubricating the cross guide head 28 and the like adheres to the compression piston 14 and the expansion piston 18, thereby preventing the refrigeration efficiency from being reduced by entering the compression space 16 and the expansion space 20.
[0043]
Further, the space (hereinafter, referred to as a back pressure chamber) 39 sandwiched between the oil seal bellows 37 and the compression piston 14 or the expansion piston 18 is sealed by the oil seal bellows 37.
[0044]
Therefore, when the compression piston 14 and the expansion piston 18 reciprocate, the atmosphere in the back pressure chamber 39 is compressed and expanded, and the energy required for the compression and expansion becomes a motor load, thereby lowering the cooling heat generation efficiency.
[0045]
Therefore, a buffer tank 41 in which the back pressure chamber 39 and the crank chamber 23 are connected via a bellows 40 is provided.
[0046]
Further, a working gas side heat exchanger 35 is provided so as to cover the compression space 16 or to surround the gas flow path S communicating the compression space 16 and the heat storage unit 22, so that the cooling water circulates. ing.
[0047]
In the Stirling refrigerator unit 4 having such a configuration, when the compression piston 14 moves from the bottom dead center to the top dead center, the working gas in the compression space 16 is compressed. During this time, the expansion piston 18 moves upward and reaches the top dead center, and then moves downward.
[0048]
The working gas compressed with the upward movement of the compression piston 14 flows through the gas flow path S and is sent to the expansion section 21 side, and when the expansion piston 18 moves down, the working gas passes through the heat storage section 22 and expands in the expansion space. 20.
[0049]
When the working gas passes through the heat storage unit 22, the heat is stored in the heat storage unit 22.
[0050]
As the expansion piston 18 reaches the bottom dead center, the compression piston 14 moves from the top dead center to the bottom dead center, and the working gas expands.
[0051]
Since the expansion process at this time is an isothermal expansion process, heat absorption accompanying the expansion is performed via the cold head 45 provided at the top of the expansion space 20, and as a result, the temperature of the cold head 45 decreases and cold heat is generated. Since the secondary refrigerant is circulated in the cold head 45 in thermal contact as described later, the secondary refrigerant is cooled by the generated cold.
[0052]
As the compression piston 14 approaches the bottom dead center, the expansion piston 18 starts to move upward, and the working gas exchanges heat with the heat storage unit 22 via the gas passage S and returns to the compression space 16.
[0053]
By operating such a cycle as one cycle, the cold heat of the cold head 45 is used for the cold heat utilization device 3.
[0054]
The heat transfer device 6 includes a cold heat source-side heat exchanger for exchanging heat between the cold and the secondary refrigerant, and the cold heat source-side heat exchanger is formed by the cold head 45 described above. Hereinafter, the cold head 45 is referred to as a cold heat source side heat exchanger 45.
[0055]
The heat transfer device 6 has a secondary refrigerant pump 46 that circulates the secondary refrigerant to the cold heat utilization equipment 3 as a main component.
[0056]
When the Stirling refrigerator unit 4 compresses the working gas, the temperature of the working gas rises, and when the working gas is sent to the expansion section 21 via the heat storage section 22 in a state where the temperature has risen, the cooling heat generation efficiency decreases. For this reason, a cooling water device 5 is provided to release the heat of the working gas to the atmosphere and transfer it to the expansion section 21.
[0057]
In the cooling water device 5, a cooling water passage is formed so as to surround the gas flow passage S between the compression space 16 and the heat storage unit 22 in the Stirling refrigerator unit 4, and an operation for exchanging heat between the working gas and the cooling water is performed. A gas-side heat exchanger 35, a radiator 65 that is an air-side heat exchanger that exchanges heat of the cooling water exchanged by the working gas-side heat exchanger 35 with the atmosphere, and sends air to the radiator 65 to cool the cooling water and the air. And a cooling water pump 67 that circulates cooling water between the working gas side heat exchanger 35 and the radiator 65.
[0058]
The refrigerant chiller unit 8 includes a compressor 71 for compressing a low-temperature refrigerant such as R404A, a condenser 72 for exchanging heat from the compressor 71 with outside air to condense the refrigerant, and a decompression for decompressing the refrigerant from the condenser 72. The main components of the device 74 include an evaporator 75 for exchanging heat between the refrigerant depressurized by the decompression device 74 and the secondary refrigerant to cool the secondary refrigerant, a receiver tank 73 for adjusting the amount of circulating refrigerant, and the like. .
[0059]
The evaporator 75 is a heat exchanger having a double pipe structure or a plate-type two-circuit heat exchanger. The refrigerant and the secondary refrigerant circulate, and the refrigerant absorbs heat from the secondary refrigerant and evaporates. Thereby, the secondary refrigerant is cooled.
[0060]
The control device 7 has a temperature detector 76 for detecting the secondary refrigerant, a register 77 for storing the detected temperature, and settings for operating and stopping the Stirling refrigerator unit 4 and the refrigerant chiller unit 8 when the temperature reaches a preset temperature. It has a memory 78 in which the values are stored, a control unit 79 for reading the set values from the memory 78, comparing the contents with the contents of the register 77, and operating and stopping the Stirling refrigerator unit 4 and the refrigerant chiller unit 8 and the like.
[0061]
The temperature of the secondary refrigerant is detected at predetermined time intervals, and a plurality of measurement results are stored in the register 77.
[0062]
Next, the operation of the Stirling cold heat supply system 1 having such a configuration and a control method thereof will be described.
[0063]
FIG. 3 is a diagram schematically showing a pull-down characteristic (solid line) (hereinafter referred to as a pull-down characteristic) in the Stirling refrigerator unit 4 and a pull-down characteristic (dashed-dotted line) in the refrigerant chiller unit 8. As can be seen from the figure, at startup, the temperature of the Stirling refrigerator unit 4 drops more slowly than the refrigerant chiller unit 8 and can be lowered to a temperature of -80 ° C or less.
[0064]
On the other hand, in the refrigerant chiller unit 8 using R404A as the refrigerant, the temperature drops faster than the Stirling refrigerator unit 4 at startup, but it is difficult to lower the temperature to lower than −40 ° C.
[0065]
Therefore, in the present invention, as shown in FIG. 4, the refrigerant chiller unit 8 is operated at the time of startup (the area indicated by a dashed line), and reaches a temperature range (for example, −40 ° C.) where the temperature drop rate of the refrigerant chiller unit 8 becomes slow. Then, by switching to the operation of the Stirling refrigerator unit 4, the pull-down time is shortened while maintaining the cold heat supply capability up to extremely low temperatures.
[0066]
Such operation control will be described with reference to the flowchart shown in FIG. In addition, when the temperature of the secondary refrigerant is T, (1) when T ≧ −35 ° C., when (2) −35 ° C.> T ≧ −40 ° C., (3) -40 In the case of ℃> T ≧ −76 ° C., the processing is performed in the case of (4) −76 ° C.> T ≧ −80 ° C. and in the case of (5) T <−− 80 ° C.
[0067]
In the following description, a case will be described in which control is performed based on temperatures such as −35 ° C., −40 ° C., −76 ° C., and −80 ° C., but such a temperature is merely an example as described below. I will add
[0068]
That is, −40 ° C. is an example of the reached temperature of the secondary refrigerant by the refrigerant chiller unit 8, and −80 ° C. is an example of the temperature required by the cold heat utilization device 3. Depending on the type of the refrigerant in the refrigerant chiller unit 8 and the configuration including the size of the chiller 8, the ultimate temperature of the refrigerant chiller unit 8 may be different, and the temperature required for the cold heat utilization device 3 is also other than -80 ° C. Sometimes.
[0069]
The temperature of -35 ° C. is an example of a temperature at which the pull-down characteristic begins to become noticeable because the pull-down characteristic of the refrigerant chiller unit 8 approaches a temperature at which the pull-down characteristic decreases (the temperature decrease rate decreases). As in the case of the temperature, the temperature differs depending on the refrigerant and configuration in the refrigerant chiller unit 8.
[0070]
Further, at −76 ° C., since the Stirling refrigerator unit 4 supplies cold heat in a certain temperature range by repeating the operation and the stop, the operating and stopping conditions of the Stirling refrigerator unit 4 are set so that the cooling heat in this temperature range can be supplied. Is a setting parameter determined by the temperature required of the cold heat utilization device 3 as a matter of course.
[0071]
Then, when the system is started, that is, when the operation is started, it is first determined whether or not the temperature of the secondary refrigerant is within a temperature range of T ≧ −35 ° C. in (1). Only the unit 8 is operated (the processing of steps SA1 → SA2).
[0072]
As a result, the secondary refrigerant exchanges heat with the refrigerant in the evaporator 75 and is cooled to lower the temperature. As shown in FIGS. 3 and 4, the temperature drop of the secondary refrigerant due to the operation of the refrigerant chiller unit 8 is faster than the temperature drop of the secondary refrigerant by the Stirling refrigerator unit 4, so that the pull-down time can be reduced. become.
[0073]
Next, it is determined whether or not the temperature of the secondary refrigerant is within the temperature range of -2 ° C.> − 35 ° C.> T ≧ −40 ° C. In this temperature range, the Stirling refrigerator unit 4 is also operated. Then, simultaneous operation with the refrigerant chiller unit 8 is performed (the processing of steps SA1 → SA3 → SA4).
[0074]
As described above, since the temperature decrease rate decreases as the temperature of the refrigerant chiller unit 8 approaches the ultimate temperature, if the temperature reaches the ultimate temperature of −40 ° C., the pull-down time may become longer. There is.
[0075]
Therefore, when the dulling of the pull-down characteristic starts to become remarkable, the simultaneous operation with the Stirling refrigerator unit 4 is performed, so that the pull-down time can be further reduced.
[0076]
In this way, when the temperature of the secondary refrigerant becomes −40 ° C. or less and enters the temperature range of −40 ° C.> T ≧ −76 ° C. in (3), the operation of the refrigerant chiller unit 8 is stopped and the Stirling refrigerator The operation is switched to the operation of only the unit 4 (the processing of steps SA1 → SA3 → SA5 → SA6).
[0077]
Since the ultimate temperature of the refrigerant chiller unit 8 is −40 ° C., even if the refrigerant chiller unit 8 is operated any more, the secondary refrigerant cannot be cooled. Is cooled. Therefore, the operation of the refrigerant chiller unit 8 is stopped, and only the operation of the Stirling refrigerator unit 4 is performed.
[0078]
When the Stirling refrigerator unit 4 starts operating and the temperature of the secondary refrigerant falls within the range of −76 ° C.> T ≧ −80 ° C. in (4), it is determined whether or not the temperature of the secondary refrigerant continues to drop. .
[0079]
As a result, if the temperature of the secondary refrigerant continues to decrease, the current state in which only the Stirling refrigerator unit 4 is operated is maintained (the processing of steps SA1, SA3, SA5, SA8, SA9, and SA6).
[0080]
On the other hand, when the temperature of the secondary refrigerant has stopped decreasing, it is determined that the secondary refrigerant has reached the desired temperature, and the operation of the Stirling refrigerator unit 4 is also stopped (step SA1 → SA3 → SA5 → SA8 → SA9 → SA10).
[0081]
The determination as to whether or not the temperature drop is continued is made based on a temperature change obtained from the temperatures of the plurality of secondary refrigerants stored in the register 77.
[0082]
Finally, when the temperature of the secondary refrigerant reaches T <−80 ° C. in (5), the operation of the Stirling refrigerator unit 4 is stopped because the secondary refrigerant has reached the desired temperature (step SA1 → SA3 → SA5 → SA8 → SA10).
[0083]
As described above, when the operation of the Stirling chilled heat supply system 1 is started and pull-down is performed, only the refrigerant chiller unit 8 is operated to shorten the pull-down time. It becomes possible and convenience is improved.
[0084]
Next, a second embodiment of the present invention will be described with reference to the drawings. The description of the same configuration as in the first embodiment will be omitted as appropriate.
[0085]
In the first embodiment, in order to shorten the pull-down time, only the refrigerant chiller unit 8 is operated when the operation of the Stirling chilled heat supply system 1 is started. Control for switching to operation of only the refrigerator unit 4 was performed.
[0086]
On the other hand, in the present embodiment, as shown in FIG. 6, the pull-down time is further reduced by simultaneously operating the refrigerant chiller unit 8 and the Stirling refrigerator unit 4 at startup. .
[0087]
In FIG. 6, a two-dot chain line indicates a case where the refrigerant chiller unit 8 and the Stirling refrigerator unit 4 are simultaneously operated, and a solid line indicates a pull-down characteristic when only the Stirling refrigerator unit 4 is operated. I have. In order to show the difference from the pull-down characteristic in the configuration according to the first embodiment, the pull-down characteristic in the first embodiment is indicated by a dotted line.
[0088]
FIG. 7 is a flowchart showing the operation control procedure in such a case. As a large control flow, (1) T ≧ -40 ° C., (2) T <-40 ° C., (3) -40 In the case of ° C>T> -76 ° C, the process is divided into the case of (4) T ≦ -80 ° C.
[0089]
First, when the Stirling cold energy supply system 1 is started, it is determined whether or not the temperature of the secondary refrigerant is within the temperature range of T ≧ −40 ° C. (1). The temperature of the secondary refrigerant immediately after startup is often room temperature, and in such a case, the Stirling refrigerator unit 4 and the refrigerant chiller unit 8 are operated (the processing of steps SB1, SB2, and SB3).
[0090]
In the case of this control, the determination process at -35 ° C. is not provided as in the first embodiment. This is because, as is clear from the above description, since the simultaneous operation of the Stirling refrigerator unit 4 and the refrigerant chiller unit 8 is performed immediately after the start-up, it is necessary to make the pull-down characteristic of the refrigerant chiller unit 8 slow down. Because there is no.
[0091]
When the Stirling refrigerator unit 4 and the refrigerant chiller unit 8 are simultaneously operated and the temperature of the secondary refrigerant decreases, and the temperature falls within the temperature range of T <−40 ° C. in (2), the operation of the refrigerant chiller unit 8 is further continued. It does not make sense to do so, and rather the refrigerant chiller unit 8 becomes a thermal load, so the operation of the refrigerant chiller unit 8 is stopped (the processing of steps SB1, SB2, and SB4).
[0092]
Thereafter, when the temperature of the secondary refrigerant is in the temperature range of −3 ° C.>T> −76 ° C. in (3), only the Stirling refrigerator unit 4 is operated, and the temperature change of the secondary refrigerant is determined.
[0093]
As a result, when the temperature of the secondary refrigerant continues to drop, the current state in which only the Stirling refrigerator unit 4 is operated is maintained (the processing of steps SB1, SB5, SB6, and SB4).
[0094]
On the other hand, when the temperature of the secondary refrigerant has stopped decreasing, it is determined that the secondary refrigerant has reached the desired temperature, and the operation of the Stirling refrigerator unit 4 is also stopped (step SB1 → SB5 → SB6 → SB7). processing).
[0095]
Finally, when the temperature of the secondary refrigerant becomes T <−− 80 ° C. in (4), the operation of the Stirling refrigerator unit 4 is stopped because the secondary refrigerant has reached the desired temperature (step SB1 → SB5 → SB7).
[0096]
As described above, immediately after the start, the Stirling refrigerator unit 4 and the refrigerant chiller unit 8 are operated simultaneously, so that the pull-down time can be greatly reduced, and the cold heat utilization equipment 3 can be used promptly. Convenience is improved.
[0097]
Next, a third embodiment of the present invention will be described with reference to the drawings. The description of the same configuration as that described above will be appropriately omitted.
[0098]
In the first and second embodiments, the pull-down time is reduced by operating the refrigerant chiller unit 8 only when the temperature of the secondary refrigerant is −40 ° C. or higher, such as when the Stirling cold heat supply system 1 is started. Was shortened.
[0099]
In the case of such a configuration, the refrigerant chiller unit 8 was not used at all during use (when the temperature required by the cold energy utilization device 3 was reached and the utilization of the cold energy utilization device 3 was started).
[0100]
This is because the temperature required by the cold heat utilization device 3 is extremely low at −80 ° C. and the ultimate temperature of the refrigerant chiller unit 8 is −40 ° C. Therefore, cooling of the secondary refrigerant using the refrigerant chiller unit 8 is performed. It was because they could not do it.
[0101]
Therefore, in the present embodiment, when the temperature of the secondary refrigerant is −40 ° C. or more, the secondary refrigerant is cooled by the refrigerant chiller unit 8 and the temperature of the secondary refrigerant becomes −40 ° C. or less. The cooling water of the Stirling refrigerator unit 4 is cooled by the refrigerant chiller unit 8.
[0102]
As described above, in the Stirling refrigerating unit 4, in order to increase the efficiency of generating cold heat, the working gas on the working gas side heat exchanger 35 in the cooling water device 5 and the working gas, which has been compressed in the compression section and has become hot, And heat exchange.
[0103]
At this time, the heat of the working gas is absorbed by the cooling water due to the heat exchange, and the cooling water is circulated to the radiator 65 and radiated to the atmosphere.
[0104]
Therefore, by causing the heat exchange between the refrigerant and the cooling water in the evaporator 75 of the refrigerant chiller unit 8 having a lower temperature than the atmosphere, the cooling water becomes lower in temperature, and as a result, the temperature of the working gas can also be lowered. become.
[0105]
By lowering the temperature of the working gas, the cycle efficiency in the Stirling refrigerator unit 4 is increased, the cooling heat generation efficiency is improved, the temperature drop of the secondary refrigerant can be increased, and the ultimate temperature of the Stirling refrigerator is also reduced. Be improved.
[0106]
With such an effect, as shown in FIG. 13, it is possible to generate cold heat corresponding to the case where a plurality of Stirling refrigerator units 4 are used, and to operate the refrigerant chiller unit 8 at all times. Economic efficiency is improved compared to the case.
[0107]
FIG. 8 is a circuit diagram showing a configuration of the Stirling cooling / heating supply system 1 having such an operation. The configuration of the refrigerant chiller unit 8 and the configuration of the cooling water device 5 are different from the configuration shown in FIG.
[0108]
That is, a second evaporator 80 and a second decompression device 81 are additionally provided in the refrigerant chiller unit 8, and the circulation path of the refrigerant is switched by a three-way valve (switching valve) 82. The second evaporator 80 replaces the radiator 65 of the cooling water device 5.
[0109]
In such a configuration, when the secondary refrigerant is cooled by the refrigerant chiller unit 8, the three-way valve 82 is switched so that the refrigerant circulates in the flow path indicated by the solid arrow.
[0110]
Thereby, the refrigerant from the compressor 71 exchanges heat with the outside air in the condenser 72 and condenses, and an appropriate amount of the refrigerant is supplied to the pressure reducing device 74 via the receiver tank 73. Thereafter, the refrigerant is depressurized by the decompression device 74 and exchanges heat with the secondary refrigerant in the evaporator 75.
[0111]
The secondary refrigerant is cooled by this heat exchange, and the refrigerant evaporates and returns to the compressor 71 through the evaporator 75.
[0112]
On the other hand, when cooling water is cooled by the refrigerant chiller unit 8, the three-way valve 82 is switched so that the refrigerant circulates in the flow path indicated by the dotted arrow. At this time, the cooling water pump 67 is operated.
[0113]
Thereby, the refrigerant from the compressor 71 exchanges heat with the outside air in the condenser 72 and condenses, and an appropriate amount of this refrigerant is supplied to the second decompression device 81 via the receiver tank 73 and decompressed. Thereafter, the refrigerant is supplied to the second evaporator 80, where it exchanges heat with the cooling water, evaporates, and returns to the compressor 71. The cooling water is cooled.
[0114]
FIG. 9 is a diagram showing the pull-down characteristics in such a configuration. The one-dot chain line indicates the pull-down characteristics when the secondary refrigerant is cooled by the refrigerant chiller unit 8, and the solid line indicates that the cooling water is cooled by the refrigerant chiller unit 8. FIG. Note that the dotted line in the figure shows the pull-down characteristics in the case of the first embodiment for comparison.
[0115]
As is clear from this figure, it can be understood that when the cooling water is cooled by the refrigerant chiller unit 8, the cold heat generation ability of the Stirling refrigerator unit 4 is improved, and thus the pull-down characteristic is also improved. In addition, the improvement in the cold heat generation capability of the Stirling refrigerator unit 4 appears as a change in the slope of the pull-down characteristic.
[0116]
FIG. 10 is a flowchart showing an operation method of the Stirling cold energy supply system 1 having such a configuration. When the temperature T of the secondary refrigerant is (1) T ≧ −35 ° C., (2) −35 ° C.> T ≧ In the case of −40 ° C., (3) when T <−40 ° C., (4) when −76 ° C.> T ≧ −80 ° C., and (5) when T <−80 ° C.
[0117]
In FIG. 10, the chiller (secondary refrigerant) means that the refrigerant chiller unit 8 is operating to cool the secondary refrigerant, and the chiller (cooling water) is that the refrigerant chiller unit 8 cools the cooling water. Means that it is working.
[0118]
First, when the Stirling cold heat supply system 1 is started, it is determined whether or not the temperature of the secondary refrigerant is within the range of T ≧ −35 ° C. in (1). The refrigerator unit 4 is not operated, and only the refrigerant chiller unit 8 is operated, and at that time, the three-way valve 82 is switched so as to cool the secondary refrigerant (the processing of steps SC1 → SC2 → SC3).
[0119]
In this case, simultaneous operation of the Stirling refrigerator unit 4 can be considered, but in the present invention, the Stirling refrigerator unit 4 is stopped. This is because the cooling water is not cooled because the refrigerant chiller unit 8 is used for cooling the secondary refrigerant, and in such a state, the Stirling refrigerating unit 4 cannot exhibit a predetermined cooling heat generating ability.
[0120]
Of course, the temperature of the refrigerant that has exchanged heat with the secondary refrigerant in the evaporator 75 may be lower than the temperature of the cooling water. In this case, the cooling water can be cooled although it is small, so the Stirling refrigerator unit No. 4 cannot generate a predetermined amount of cold heat, but can generate a small amount of cold heat.
[0121]
From this, simultaneous operation of the Stirling refrigerator unit 4 and the refrigerant chiller unit 8 can be performed.
[0122]
If the cooling of the secondary refrigerant proceeds and enters the temperature range of -35 ° C> T ≧ -40 ° C in (2), the temperature change of the secondary refrigerant is determined.
[0123]
As a result, if the temperature of the secondary refrigerant is falling, it is determined that the secondary refrigerant has not yet been pulled down to the temperature reached by the refrigerant chiller unit 8, and the current state is maintained (step SC1 → SC2 → SC4). → SC5 → SC6).
[0124]
On the other hand, when the temperature drop of the secondary refrigerant is stopped, it is determined that the secondary refrigerant has reached the temperature reached by the refrigerant chiller unit 8, and the three-way valve 82 is switched (step SC → SC2 → SC4 → SC5 → SC7).
[0125]
By the switching of the three-way valve 82, the refrigerant flows through the circulation path indicated by the dotted arrow shown in FIG. 8 and cools the cooling water, thereby increasing the cold heat generation capability of the Stirling refrigerator unit 4. The pull-down time can be reduced.
[0126]
Needless to say, when the pull-down is completed and the usage state is reached, there is a margin for a load change in the heat utilization device by an amount corresponding to the increase in the cooling heat generation capability, so that the performance as a system can be improved.
[0127]
Then, the temperature of the secondary refrigerant falls within the temperature range of T <−40 ° C. in (3). This state is normally maintained because the flow path switching by the three-way valve 82 has already been performed because the state normally passes through the state (2), but if not, the processing described in (2) is performed. (Steps SC1, SC1, SC2, SC4, SC7).
[0128]
Next, when the temperature of the secondary refrigerant falls within the temperature range of -76 ° C.> T ≧ −80 ° C. in (4), it is determined whether or not the temperature of the secondary refrigerant continues to drop.
[0129]
As a result, when the temperature of the secondary refrigerant is dropping, the current state is maintained (the processing of steps SC1, SC8, SC10, and SC7).
[0130]
On the other hand, if the temperature of the secondary refrigerant has stopped decreasing, it is determined that the secondary refrigerant has reached the desired temperature, and the operation of the Stirling refrigerator unit 4 is stopped. At this time, since the cooling of the cooling water is not required, the operation of the refrigerant chiller unit 8 is also stopped (the processing of steps SC1, SC8, SC10, and SC9).
[0131]
Finally, when the temperature of the secondary refrigerant reaches T <−80 ° C. in (5), the operation of the Stirling refrigerator unit 4 and the refrigerant chiller unit 8 is stopped because the secondary refrigerant has reached the desired temperature. (Steps SC1 → SC8 → SC9).
[0132]
As described above, since the refrigerant chiller unit 8 is used for cooling the secondary refrigerant and the cooling water in accordance with the temperature of the secondary refrigerant, the pull-down time can be reduced, and the generation of cold heat of the Stirling refrigerator unit 4 can be achieved. The capacity can be improved, and the performance of the Stirling cooling and heat supply system 1 can be improved.
[0133]
【The invention's effect】
As described above, according to the first aspect of the invention, a Stirling refrigerator unit that compresses and expands the working gas to generate cold heat, and cools the secondary refrigerant by the cold generated by the Stirling refrigerator unit. In a Stirling cold heat supply system including a heat transfer device that transfers a secondary refrigerant to a cold heat utilization device, a compressor that compresses the refrigerant, and a refrigerant that is discharged from the compressor exchanges heat with the outside air or water. A refrigerant chiller unit including a condenser for condensing the refrigerant, a decompression device for decompressing the refrigerant from the condenser, and an evaporator for cooling a secondary refrigerant by an evaporating action of the refrigerant decompressed by the decompression device is provided. Therefore, the pull-down time can be reduced with a simple and inexpensive configuration.
[0134]
According to the second aspect of the present invention, the working gas of the Stirling refrigerator unit is helium gas, and the refrigerant of the refrigerant chiller unit is R404A.
[0135]
According to the third aspect of the present invention, when starting the Stirling chilled heat supply system according to the first or second aspect, after operating the refrigerant chiller unit to cool the secondary refrigerant to a predetermined temperature, the Stirling refrigerator Since the unit is operated and the operation of the refrigerant chiller unit is stopped, the pull-down time can be reduced.
[0136]
According to the fourth aspect of the present invention, the period in which the Stirling refrigerator unit and the refrigerant chiller unit are simultaneously operated is provided, so that the pull-down time can be reduced.
[0137]
According to the invention according to claim 5, when the operation of the Stirling chilled heat supply system according to claim 1 or 2 is started, the secondary chiller unit is operated to simultaneously operate to a predetermined temperature to cool the secondary refrigerant. And, the operation of the Stirling refrigerator unit is started from a temperature appropriately higher than the predetermined temperature, and in this temperature range,
Since the refrigerant chiller unit and the Stirling refrigerator unit are simultaneously operated, and when the temperature reaches a predetermined temperature, the operation of the refrigerant chiller unit is stopped and only the Stirling refrigerator unit is operated, so that the pull-down time can be reduced.
[0138]
According to the invention according to claim 6, when the Stirling chilled heat supply system according to claim 1 is started to operate, the refrigerant chiller unit and the Stirling refrigerator unit are simultaneously operated to a predetermined temperature to cool the secondary refrigerant, When the predetermined temperature is reached, the operation of the refrigerant chiller unit is stopped and only the Stirling refrigerator unit is operated, so that the pull-down time can be reduced.
[0139]
According to the invention according to claim 7, a Stirling refrigerator unit that compresses and expands the working gas to generate cold heat, and cools the secondary refrigerant by the cold generated by the Stirling refrigerator unit, and cools the secondary refrigerant In a Stirling cold heat supply system including a heat transfer device that transfers heat to a utilization device, a compressor that compresses a refrigerant, and a refrigerant that condenses the refrigerant by exchanging heat with the outside air or water with the refrigerant discharged from the compressor. A decompression device for decompressing the refrigerant from the condenser, an evaporator for cooling the secondary refrigerant by an evaporating action of the refrigerant decompressed by the decompression device, A second evaporator for absorbing heat radiation from the Stirling refrigerator unit, and a switch for switching between effectively evaporating the refrigerant from the condenser with the evaporator or effectively evaporating with the second evaporator. Since a valve, simple and inexpensive construction, with shortened pull-down time, it is possible to enhance the cold generating capacity of the Stirling refrigerator unit.
[0140]
According to the invention according to claim 8, since the pressure reducing device for the evaporator and the pressure reducing device for the second evaporator are made different, the circuit configuration is simplified and the control becomes easy.
[0141]
According to the ninth aspect of the present invention, at the time of starting the operation of the Stirling chilled heat supply system according to the seventh or eighth aspect, the switching valve is configured so that the refrigerant condensed in the condenser is effectively evaporated in the evaporator. After switching the refrigerant chiller unit to cool the secondary refrigerant to a predetermined temperature, the switching valve is switched so that the refrigerant condensed in the condenser is effectively evaporated in the second evaporator. And the pull-down time can be reduced.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a Stirling cooling and heat supply system according to first and second embodiments.
FIG. 2 is a configuration diagram of a Stirling refrigerator unit applied to the description of each embodiment.
FIG. 3 is a schematic diagram of pull-down characteristics of a refrigerant chiller unit and a Stirling refrigerator unit.
FIG. 4 is a schematic diagram of a pull-down characteristic in the Stirling cold heat supply system according to the first embodiment.
FIG. 5 is a flowchart showing an operation procedure in the Stirling cooling and heat supply system according to the first embodiment.
FIG. 6 is a schematic diagram of a pull-down characteristic in the Stirling cooling / heating supply system according to the second embodiment.
FIG. 7 is a flowchart showing an operation procedure in the Stirling cooling and heat supply system according to the second embodiment.
FIG. 8 is a circuit diagram of a Stirling cooling / heating supply system according to a third embodiment.
FIG. 9 is a schematic diagram of a pull-down characteristic in the Stirling cooling / heating supply system according to the third embodiment.
FIG. 10 is a flowchart showing an operation procedure in the Stirling cooling / heating supply system according to the third embodiment.
And FIG. 11 is a circuit diagram of a Stirling cooling and heat supply system applied to the description of the related art.
FIG. 12 is a circuit diagram of a Stirling cooling / heating supply system applied to the description of the related art.
FIG. 13 is a configuration diagram of a Stirling refrigerator unit applied to the description of the related art.
[Explanation of symbols]
1 Stirling cold heat supply system
3 Cold heat utilization equipment
4 Stirling refrigerator unit
5 Cooling water equipment
6 Heat transfer device
7 Control device
8 Refrigerant chiller unit
35 Working gas side heat exchanger
45 Cold Head
71 Compressor
72 condenser
74 decompression device
75 Evaporator
76 Temperature detector
77 registers
78 memory
79 Control unit
80 Second evaporator
81 Second decompression device

Claims (9)

A Stirling refrigerator unit that generates cold heat by compressing and expanding the working gas, and a heat transfer device that cools the secondary refrigerant by the cold generated by the Stirling refrigerator unit and transfers the secondary refrigerant to the cold heat utilization device. In the Stirling cold and heat supply system with
A compressor for compressing the refrigerant,
A condenser that causes the refrigerant discharged from the compressor to exchange heat with outside air or water and condenses the refrigerant,
A decompression device for decompressing the refrigerant from the condenser,
A Stirling cold heat supply system, comprising: a refrigerant chiller unit including an evaporator for cooling the secondary refrigerant by an evaporating action of the refrigerant decompressed by the decompression device. The Stirling chiller supply system according to claim 1, wherein the working gas of the Stirling refrigerator unit is helium gas, and the refrigerant of the refrigerant chiller unit is R404A. When operating the Stirling chilled heat supply system according to claim 1 or 2, after operating the refrigerant chiller unit to cool the secondary refrigerant to a predetermined temperature, operate the Stirling refrigerator unit, and An operation method of a Stirling cold energy supply system, wherein the operation of the refrigerant chiller unit is stopped. The method according to claim 3, wherein a period is provided for simultaneously operating the Stirling refrigerator unit and the refrigerant chiller unit. When starting the operation of the Stirling chilled heat supply system according to claim 1 or 2, the refrigerant chiller unit is operated to simultaneously operate to a predetermined temperature to cool the secondary refrigerant, and appropriately from the predetermined temperature. The operation of the Stirling refrigerator unit is started from a high temperature, the refrigerant chiller unit and the Stirling refrigerator unit are simultaneously operated in this temperature range, and when the temperature reaches the predetermined temperature, the operation of the refrigerant chiller unit is stopped. Controlling the Stirling refrigerator unit to operate only the Stirling refrigerator unit. When starting operation of the Stirling chilled heat supply system according to claim 1, the refrigerant chiller unit and the Stirling refrigerator unit are simultaneously operated to a predetermined temperature to cool the secondary refrigerant, and when the temperature reaches the predetermined temperature, A method for operating a Stirling chilled heat supply system, wherein the operation of the refrigerant chiller unit is stopped and only the Stirling refrigerator unit is operated. A Stirling refrigerator unit that generates cold heat by compressing and expanding the working gas, and a heat transfer device that cools the secondary refrigerant by the cold generated by the Stirling refrigerator unit and transfers the secondary refrigerant to the cold heat utilization device. In the Stirling cold and heat supply system with
A compressor for compressing the refrigerant,
A condenser that causes the refrigerant discharged from the compressor to exchange heat with outside air or water and condenses the refrigerant,
A decompression device for decompressing the refrigerant from the condenser,
An evaporator for cooling the secondary refrigerant by an evaporating effect of the refrigerant decompressed by the decompression device,
A second evaporator that evaporates the refrigerant depressurized by the decompression device and absorbs heat radiation from the Stirling refrigerator unit;
A stirling cooling / heating supply system, comprising: a switching valve that switches whether the refrigerant from the condenser is effectively evaporated by the evaporator or is effectively evaporated by the second evaporator. The Stirling cold heat supply system according to claim 7, wherein the pressure reducing device for the evaporator is different from the pressure reducing device for the second evaporator. When starting the Stirling chilled heat supply system according to claim 7 or 8, the refrigerant chiller unit is switched by switching the switching valve so that the refrigerant condensed in the condenser is effectively evaporated in the evaporator. And cooling the secondary refrigerant to a predetermined temperature and then switching the switching valve so that the refrigerant condensed in the condenser evaporates effectively in the second evaporator. How to operate the cold heat supply system.

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