JP2004257610A - Method of manufacturing refrigerant cycle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a refrigerant cycle device capable of easily determining an optimum amount of sealed refrigerant. <P>SOLUTION: The amount of the sealed refrigerant is determined by multiplying a predetermined specified factor C by a value obtained by multiplying the rated motor input W of a compressor 10 by a rated rotational speed S. Also, the amount of the sealed refrigerant is regulated according to the pipe length of a refrigerant circuit. After the amount of the refrigerant calculated by this method is sealed in the refrigerant cycle device, the refrigerant cycle device is operated to investigate the coefficient of performance (COP) and the capacity (cooling capacity or heating capacity) in each application of the compressor 10. This experiment is repeatedly performed while changing the sealed amount of the refrigerant, and the amount of the refrigerant capable of providing excellent COP and capacity in each application is determined as a sealed refrigerant amount M. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a refrigerant cycle device that forms a predetermined refrigerant circuit by connecting a compressor, a gas cooler, a throttle device, and an evaporator with piping.
[0002]
[Prior art]
In this type of conventional refrigerant cycle device, a refrigerant cycle (refrigerant circuit) is configured by connecting a compressor, a gas cooler, a throttle means (expansion valve and the like), an evaporator, and the like in order in a circular pipe. Refrigerant gas is sucked into the low pressure chamber side of the cylinder from the suction port of the rotary compression element of the compressor, and is compressed by the operation of the rollers and the vanes to become high temperature and high pressure refrigerant gas. The gas is discharged to the gas cooler through the chamber. After the refrigerant gas radiates heat in this gas cooler, it is throttled by throttle means and supplied to the evaporator. Therefore, a cycle in which heat is absorbed and evaporated and then sucked into the rotary compression element is repeated.
[0003]
Here, in recent years, in order to deal with global environmental problems, even in this type of refrigerant cycle, carbon dioxide (CO ₂ ), which is a natural refrigerant, is used as a refrigerant without using conventional chlorofluorocarbons, and the high pressure side is set to a supercritical pressure. A device using a refrigerant cycle to be operated has been developed (for example, see Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Publication No. Hei 7-18602
[Problems to be solved by the invention]
By the way, based on the inner diameter of each refrigerant pipe, the pressure of the used refrigerant, the temperature of the used refrigerant, the refrigerant density, the refrigerant volume, and the like, the refrigerant enclosed in such a refrigerant cycle device is filled with a predetermined amount of refrigerant, and then experimentally. In this case, the refrigerant cycle device is operated, and the refrigerant is additionally charged or discharged based on the actual operation state to determine the optimum amount of the charged refrigerant. For this reason, every time the model is changed, it is necessary to find the optimum amount of the charged refrigerant in the refrigerant cycle device.
[0006]
In particular, when carbon dioxide is used as a refrigerant, since carbon dioxide does not condense in the gas cooler, it is difficult to uniquely determine the density of the refrigerant, the number of experiments is significantly larger than other refrigerants, and the development cost is reduced. Was causing an increase.
[0007]
The present invention has been made to solve such a conventional technical problem, and an object of the present invention is to provide a method of manufacturing a refrigerant cycle device capable of easily determining an optimum amount of charged refrigerant.
[0008]
[Means for Solving the Problems]
That is, in the refrigerant cycle device of the present invention, the amount of the charged refrigerant is determined by multiplying a value obtained by multiplying the rated motor input of the compressor and the rated rotation speed by a predetermined coefficient which is determined in advance. It is characterized in that the amount of the charged refrigerant is adjusted according to the length of the circuit piping.
[0009]
As described above, by determining the amount of refrigerant to be charged into the refrigerant cycle device based on the factors contributing to the capacity of the compressor, the number of experiments for determining the optimum amount of charged refrigerant can be significantly reduced.
[0010]
According to the third aspect of the invention, in addition to the above inventions, carbon dioxide is used as the refrigerant, so that it can contribute to environmental problems.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional side view of an internal intermediate pressure type multi-stage (two-stage) compression type rotary compressor 10 having first and second rotary compression elements 32 and 34 as an embodiment of a compressor used in the refrigerant cycle device of the present invention. FIG. 2 is a refrigerant circuit diagram of the refrigerant cycle device of the present invention.
[0012]
In each of the drawings, reference numeral 10 denotes an internal intermediate pressure type multistage compression type rotary compressor using carbon dioxide (CO ₂ ) as a refrigerant. The compressor 10 includes a cylindrical hermetic container 12 made of a steel plate and an inner space of the hermetic container 12. An electric element 14 as a driving element disposed and housed on the upper side, and a first rotary compression element 32 (first stage) and a first rotary compression element 32 disposed below the electric element 14 and driven by the rotating shaft 16 of the electric element 14. The rotary compression mechanism 18 includes two rotary compression elements 34 (second stage).
[0013]
The closed container 12 has an oil reservoir at the bottom, a container body 12A that houses the electric element 14 and the rotary compression mechanism 18, and a substantially bowl-shaped end cap (lid) 12B that closes an upper opening of the container body 12A. A circular mounting hole 12D is formed in the center of the upper surface of the end cap 12B, and a terminal (wiring omitted) 20 for supplying electric power to the electric element 14 is mounted in the mounting hole 12D. Have been.
[0014]
The electric element 14 is a so-called magnetic pole concentrated winding type DC motor, and is inserted into the stator 22 annularly attached along the inner peripheral surface of the upper space of the closed casing 12 with a slight interval provided inside the stator 22. And an installed rotor 24. The rotor 24 is fixed to the rotating shaft 16 that extends vertically through the center. The stator 22 has a laminated body 26 in which donut-shaped electromagnetic steel sheets are laminated, and a stator coil 28 wound around teeth of the laminated body 26 by a direct winding (concentrated winding) method. The rotor 24 is formed of a laminated body 30 of electromagnetic steel sheets similarly to the stator 22, and is formed by inserting a permanent magnet MG into the laminated body 30.
[0015]
An intermediate partition plate 36 is held between the first rotary compression element 32 and the second rotary compression element 34. That is, the first rotary compression element 32 and the second rotary compression element 34 include an intermediate partition plate 36, an upper cylinder 38, a lower cylinder 40 disposed above and below the intermediate partition plate 36, The upper and lower rollers 46 and 48 are eccentrically rotated by upper and lower eccentric portions 42 and 44 provided on the rotating shaft 16 with a phase difference of 180 degrees in the inside 40, and the upper and lower cylinders abut on the upper and lower rollers 46 and 48. The vanes 50 and 52 partitioning the inside of the cylinders 38 and 40 into a low pressure chamber side and a high pressure chamber side, respectively, and the upper opening surface of the upper cylinder 38 and the lower opening surface of the lower cylinder 40 are closed so that the bearing of the rotating shaft 16 is closed. An upper supporting member 54 and a lower supporting member 56 are also used as supporting members.
[0016]
On the other hand, the upper support member 54 and the lower support member 56 have a suction passage 60 (the upper suction passage is not shown) communicating with the insides of the upper and lower cylinders 38 and 40 through a suction port (not shown), and a part thereof is recessed. The discharge muffling chambers 62 and 64 formed by closing the recess with the upper cover 66 and the lower cover 68 are provided.
[0017]
The discharge muffling chamber 64 and the inside of the closed container 12 are communicated with each other by a communication passage penetrating the upper and lower cylinders 38 and 40 and the intermediate partition plate 36, and an intermediate discharge pipe 121 is provided upright at the upper end of the communication passage. The intermediate-pressure refrigerant gas compressed by the first rotary compression element 32 is discharged from the intermediate discharge pipe 121 into the closed container 12.
[0018]
As the refrigerant, the above-mentioned carbon dioxide (CO ₂ ), which is a natural refrigerant in consideration of flammability and toxicity, is used for the earth environment, is used. Existing oils such as alkylbenzene oil, ether oil, ester oil, and PAG (polyalkyl glycol) are used.
[0019]
Further, on the side surface of the container body 12A of the closed container 12, the suction passages 60 (the upper side is not shown) of the upper supporting member 54 and the lower supporting member 56, the discharge muffling chamber 62, and the upper side of the upper cover 66 (the upper side of the electric element 14). The sleeves 141, 142, 143, and 144 are respectively welded and fixed at positions corresponding to the lower end (positions substantially corresponding to the lower ends). The sleeves 141 and 142 are vertically adjacent to each other, and the sleeve 143 is substantially on a diagonal line of the sleeve 141. The sleeve 144 is located at a position shifted from the sleeve 141 by approximately 90 degrees.
[0020]
One end of a refrigerant introduction pipe 92 for introducing refrigerant gas into the upper cylinder 38 is inserted into the sleeve 141, and one end of the refrigerant introduction pipe 92 communicates with a suction passage (not shown) of the upper cylinder 38. The refrigerant introduction pipe 92 passes through the upper side of the closed container 12 to reach the sleeve 144, and the other end is inserted and connected into the sleeve 144 and communicates with the inside of the closed container 12.
[0021]
One end of a refrigerant introduction pipe 94 for introducing refrigerant gas into the lower cylinder 40 is inserted and connected into the sleeve 142, and one end of the refrigerant introduction pipe 94 communicates with the suction passage 60 of the lower cylinder 40. A coolant discharge pipe 96 is inserted and connected into the sleeve 143, and one end of the coolant introduction pipe 96 communicates with the discharge muffling chamber 62.
[0022]
Next, the compressor 10 described above in FIG. 2 constitutes a part of the refrigerant circuit of the refrigerant cycle device of the present invention.
[0023]
That is, the refrigerant circuit of the refrigerant cycle device is configured by connecting the compressor 10, the gas cooler 154, the expansion valve 156, and the evaporator 157 by piping. The refrigerant discharge pipe 96 of the compressor 10 is connected to a gas cooler 154. The pipe exiting the gas cooler 154 is connected to an evaporator 157 via an expansion valve 156 as a pressure reducing means, and the pipe exiting the evaporator 157 is connected to a refrigerant introduction pipe 94.
[0024]
Here, the refrigerant is sealed in the compressor 10 from a service valve or the like (not shown) in the refrigerant cycle device. The amount M of the refrigerant sealed in the refrigerant cycle device is determined based on a factor contributing to the capacity of the compressor 10. ing. That is, the amount of the charged refrigerant is determined by multiplying a value obtained by multiplying the rated motor input W of the compressor and the rated rotation speed S by a predetermined coefficient C. The amount of the charged refrigerant is adjusted according to the length of each refrigerant pipe, and the refrigerant is sealed in the compressor 10 of the refrigerant cycle device.
[0025]
Then, after charging the amount of the refrigerant calculated by the above method into the compressor 10, the refrigerant cycle device is operated, and the coefficient of performance (COP) of the compressor 10 and the capacity (cooling capacity or heating capacity) in each application are used. Find out. This experiment is performed several times by changing the amount of refrigerant to be sealed, and a refrigerant having an excellent coefficient of performance and capacity in use is determined as the amount of refrigerant M to be sealed.
[0026]
Here, the enclosed refrigerant amount M actually enclosed in the refrigerant cycle device and the refrigerant amount calculated by the method will be described with reference to FIG. When the coefficient C is set to 10, for example, and the refrigerant cycle device is used for a water heater for a room temperature region, the refrigerant amount is calculated to be 630 g by the above-described calculation method. The actual optimum amount M of the filled refrigerant is 650 g as shown in FIG.
[0027]
Further, when the refrigerant cycle device is used for a water heater for a normal temperature region, the refrigerant amount is calculated to be 770 g, and the actual optimum enclosed refrigerant amount M is 800 g. Further, when the refrigerant cycle device is used for a vending machine, the refrigerant amount is calculated to be 265 g, and the actual optimum sealed refrigerant amount M is also 265 g.
[0028]
As described above, the value calculated based on the factor contributing to the capacity of the compressor 10 becomes a value very close to the actual optimum amount M of the charged refrigerant. For this reason, the number of experiments can be significantly reduced by enclosing the refrigerant amount calculated by the method and performing an experiment for determining the optimal enclosed refrigerant amount M.
[0029]
As before, based on the inner diameter of each refrigerant pipe, the pressure of the refrigerant used, the temperature of the refrigerant used, the refrigerant density and the refrigerant volume, etc., after charging a predetermined amount of refrigerant, the refrigerant cycle device is operated experimentally to optimize When the amount M of enclosed refrigerant is determined, the number of experiments for determining the optimal amount M of enclosed refrigerant necessarily increases. In particular, in the case of a refrigerant that does not condense in a gas cooler such as carbon dioxide, the density cannot be unambiguously determined, so that the number of experiments is significantly increased compared to other refrigerants, and the time and cost required for development have been increased. .
[0030]
However, the amount of refrigerant is calculated based on the factors contributing to the capacity of the compressor 10 as described above, the calculated refrigerant is charged, and the refrigerant cycle device is operated to determine the optimum charged refrigerant amount M. As a result, the optimal amount M of the charged refrigerant can be determined with a small number of experiments, so that the development cost can be significantly reduced.
[0031]
Next, the operation of the transcritical refrigerant cycle device of the present invention having the above configuration will be described. When the stator coil 28 of the electric element 14 of the compressor 10 is energized through the terminal 20 and the wiring (not shown), the electric element 14 starts and the rotor 24 rotates. By this rotation, the upper and lower rollers 46 and 48 fitted to the upper and lower eccentric portions 42 and 44 provided integrally with the rotating shaft 16 eccentrically rotate inside the upper and lower cylinders 38 and 40.
[0032]
As a result, the low-pressure refrigerant gas sucked into the low-pressure chamber side of the cylinder 40 from the suction port (not shown) through the refrigerant introduction pipe 94 and the suction passage 60 formed in the lower support member 56 is supplied to the roller 48 and the vane 52. It is compressed by the operation and becomes an intermediate pressure, and is discharged from the intermediate discharge pipe 121 into the closed container 12 through a communication passage (not shown) from the high pressure chamber side of the lower cylinder 40. Thereby, the inside of the sealed container 12 has an intermediate pressure.
[0033]
Then, the intermediate-pressure refrigerant gas in the sealed container 12 passes through a refrigerant introduction pipe 92, passes through a suction passage (not shown) formed in the upper support member 54, and passes through a suction port (not shown) to a position above the second rotary compression element 34. The refrigerant is sucked into the low pressure chamber side of the cylinder 38 and is compressed in the second stage by the operation of the roller 46 and the vane 50 to become a high pressure and high temperature refrigerant gas. The refrigerant gas is formed on the upper support member 54 from the high pressure chamber through a discharge port (not shown). The refrigerant is discharged from the refrigerant discharge pipe 96 to the outside through the discharge muffling chamber 62.
[0034]
The refrigerant gas discharged from the refrigerant discharge pipe 96 flows into the gas cooler 154, radiates heat there, and reaches the expansion valve 156. At the inlet of the expansion valve 156, the refrigerant gas is still in a gaseous state. The refrigerant is converted into a gas / liquid two-phase mixture by the pressure drop at the expansion valve 156, and flows into the evaporator 157 in that state. There, the refrigerant evaporates and absorbs heat from the surroundings. Thereafter, the cycle of sucking the refrigerant from the refrigerant introduction pipe 94 into the first rotary compression element 32 is repeated.
[0035]
As described above, the amount of the charged refrigerant is determined by multiplying the value obtained by multiplying the rated motor input W of the compressor, which is a factor contributing to the capacity of the compressor 10, by the rated rotational speed S, by the predetermined coefficient C, which is determined in advance. Since the amount of the charged refrigerant is adjusted according to the length of the piping and is charged in the compressor 10 of the refrigerant cycle device, the number of experiments for determining the optimum charged refrigerant amount M can be significantly reduced. .
[0036]
This makes it possible to easily determine the optimum amount M of the charged refrigerant, so that the time and cost required for development can be significantly reduced.
[0037]
In this embodiment, an internal intermediate pressure type multi-stage (two-stage) compression type rotary compressor is used as a compressor, but the present invention is not limited to this, and any compressor may be used.
[0038]
Further, in the embodiment, carbon dioxide is used as the refrigerant. However, the present invention is not limited thereto, and the existing refrigerant such as HC, nitrous oxide, HFC-based refrigerant is also applicable. is there. Furthermore, in the present embodiment, the refrigerant amount is calculated by setting the predetermined coefficient C to 10, but the predetermined coefficient is not limited to this value, and may be appropriately changed according to the usage of the refrigerant cycle device.
[0039]
【The invention's effect】
As described in detail above, according to the present invention, the amount of the charged refrigerant is determined by multiplying a value obtained by multiplying the rated motor input of the compressor and the rated rotation speed by a predetermined coefficient which is determined in advance. The amount of refrigerant charged is adjusted according to the length of the piping in the circuit.
[0040]
As described above, by determining the amount of refrigerant to be charged into the refrigerant cycle device based on the factors contributing to the capacity of the compressor, the number of experiments for determining the optimum amount of charged refrigerant can be significantly reduced.
[0041]
This allows the amount of refrigerant to be charged into the refrigerant cycle device to be easily determined without performing a large-scale experiment as in the past when finding the optimal amount of charged refrigerant by changing the model or the like. The time and cost required for development can be reduced.
[0042]
Further, the present invention is more effective when a refrigerant whose density cannot be uniquely determined, such as carbon dioxide, is used.
[0043]
Further, the use of carbon dioxide as a refrigerant can contribute to environmental problems.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a compressor of an embodiment used in a refrigerant cycle device of the present invention.
FIG. 2 is a refrigerant circuit diagram of the refrigerant cycle device of the present invention.
FIG. 3 is a diagram showing an optimum amount of charged refrigerant for each application.
[Explanation of symbols]
Reference Signs List 10 Compressor 12 Closed container 14 Electric element 32 First rotary compression element 34 Second rotary compression element 92, 94 Refrigerant introduction pipe 96 Refrigerant discharge pipe 154 Gas cooler 156 Expansion valve (throttle means)
157 evaporator

Claims (3)

In a refrigerant cycle device that constitutes a predetermined refrigerant circuit by connecting a compressor, a gas cooler, a throttle device, an evaporator, and the like,
A method of manufacturing a refrigerant cycle device, wherein a sealed refrigerant amount is determined by multiplying a value obtained by multiplying a rated motor input of the compressor and a rated rotation speed by a predetermined coefficient. 2. The method according to claim 1, wherein the amount of the filled refrigerant is adjusted according to a length of the refrigerant circuit. The method according to claim 1, wherein the refrigerant is carbon dioxide.

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