MXPA98000237A - Refrigerant circulation apparatus and method for assembling a refrigerating circuit - Google Patents
Refrigerant circulation apparatus and method for assembling a refrigerating circuitInfo
- Publication number
- MXPA98000237A MXPA98000237A MXPA/A/1998/000237A MX9800237A MXPA98000237A MX PA98000237 A MXPA98000237 A MX PA98000237A MX 9800237 A MX9800237 A MX 9800237A MX PA98000237 A MXPA98000237 A MX PA98000237A
- Authority
- MX
- Mexico
- Prior art keywords
- refrigerant
- machine oil
- compressor
- oil
- solubility
- Prior art date
Links
- 239000003507 refrigerant Substances 0.000 title claims abstract description 643
- 239000007788 liquid Substances 0.000 claims abstract description 324
- 239000010721 machine oil Substances 0.000 claims abstract description 273
- 239000003921 oil Substances 0.000 claims abstract description 189
- 230000001603 reducing Effects 0.000 claims abstract description 120
- 238000003860 storage Methods 0.000 claims abstract description 117
- 238000001816 cooling Methods 0.000 claims abstract description 51
- 238000001704 evaporation Methods 0.000 claims abstract description 41
- 238000009833 condensation Methods 0.000 claims abstract description 38
- 230000005494 condensation Effects 0.000 claims abstract description 38
- 230000005484 gravity Effects 0.000 claims abstract description 6
- 238000005057 refrigeration Methods 0.000 claims description 48
- 230000001276 controlling effect Effects 0.000 claims description 12
- 230000000875 corresponding Effects 0.000 claims description 11
- 238000007789 sealing Methods 0.000 claims description 11
- 238000011084 recovery Methods 0.000 claims description 6
- 238000001514 detection method Methods 0.000 claims description 5
- 239000003638 reducing agent Substances 0.000 claims description 4
- 238000004364 calculation method Methods 0.000 claims description 2
- 230000001808 coupling Effects 0.000 claims description 2
- 238000010168 coupling process Methods 0.000 claims description 2
- 238000005859 coupling reaction Methods 0.000 claims description 2
- 239000002826 coolant Substances 0.000 abstract description 24
- 239000007789 gas Substances 0.000 description 34
- 239000012071 phase Substances 0.000 description 31
- 238000004378 air conditioning Methods 0.000 description 26
- 239000003570 air Substances 0.000 description 22
- 238000010586 diagram Methods 0.000 description 22
- AFYPFACVUDMOHA-UHFFFAOYSA-N Chlorotrifluoromethane Chemical compound FC(F)(F)Cl AFYPFACVUDMOHA-UHFFFAOYSA-N 0.000 description 19
- KWKXNDCHNDYVRT-UHFFFAOYSA-N Dodecylbenzene Chemical compound CCCCCCCCCCCCC1=CC=CC=C1 KWKXNDCHNDYVRT-UHFFFAOYSA-N 0.000 description 13
- 238000007906 compression Methods 0.000 description 13
- 238000004090 dissolution Methods 0.000 description 13
- 238000005461 lubrication Methods 0.000 description 13
- 230000002829 reduced Effects 0.000 description 8
- 230000032258 transport Effects 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 230000006399 behavior Effects 0.000 description 6
- 238000004891 communication Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000002309 gasification Methods 0.000 description 5
- RTZKZFJDLAIYFH-UHFFFAOYSA-N diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 4
- 239000000428 dust Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000003990 capacitor Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000003247 decreasing Effects 0.000 description 3
- 239000007791 liquid phase Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000002480 mineral oil Substances 0.000 description 3
- 235000010446 mineral oil Nutrition 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 230000035695 Efflux Effects 0.000 description 2
- 230000003750 conditioning Effects 0.000 description 2
- 101710041633 cprG Proteins 0.000 description 2
- 239000010696 ester oil Substances 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 230000001737 promoting Effects 0.000 description 2
- 239000011555 saturated liquid Substances 0.000 description 2
- 230000007958 sleep Effects 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 238000009423 ventilation Methods 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- VZGDMQKNWNREIO-UHFFFAOYSA-N Carbon tetrachloride Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 1
- 206010013647 Drowning Diseases 0.000 description 1
- -1 R.410A and R.407C Chemical class 0.000 description 1
- 239000012080 ambient air Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atoms Chemical class [H]* 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 230000000414 obstructive Effects 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 230000036961 partial Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Abstract
The present invention relates to a refrigerant circulation apparatus having a refrigerant circuit, wherein a compressor, a condenser, a pressure reducing device, and an evaporator are consecutively connected, by means of refrigerant tubes, this circulating apparatus comprising Coolant: a liquid storage vessel connected between the condenser and the pressure reducing device, to allow the oil droplets to flow out in a suspended form, by using a refrigerating machine oil that does not exhibit solubility or exhibit a very weak solubility in terms of a solubility weight ratio of the refrigerating machine oil in a liquid refrigerant under conditions of condensing pressure and condensation temperature, and which does not exhibit solubility or exhibits a very weak solubility in terms of a in solubility weight of the machine oil of cooling in the liquid refrigerant under conditions of evaporation pressure and evaporation temperature, and having a specific gravity smaller than the refrigerant
Description
r? REFRIGERANT CIRCULATION APPARATUS AND METHOD FOR ASSEMBLING A REFRIGERANT CIRCUIT
Detailed Description of the Invention Technical Field to Which the Invention Belongs The present invention relates to a refrigerant circulation apparatus having a refrigerant circuit, wherein it is difficult to dissolve the oil of a refrigerating machine. in a refrigerant as in the case where, for example, a refrigerant based on hydrofluorocarbon (HFC) is used as a refrigerant, and an oil based on alkylbenzene as a refrigerating machine oil. Prior Art In Figure 20 there is shown an example of a conventional refrigeration and air-conditioning cycle apparatus. In a case where a machine oil is used
Refrigeration, such as alkylbenzene, having a poor compatibility with respect to a hydrofluorocarbon (HFC) based refrigerant, as shown in the Application for
Japanese Patent Open Number 208819/1995, the return of the oil from an accumulator provided on the low side
Pressure, in which the solubility of the oil of the refrigeration machine in the liquid refrigerant declines, has been until now a major problem in the reliability of a compressor. Figure 20 shows a refrigeration and air conditioning cycle apparatus, wherein a hydrofluorocarbon-based refrigerant and an oil having a low solubility are used, as a refrigerant and as a refrigerating machine oil, respectively, wherein the reference numeral 1 denotes a compressor for compressing a refrigerant gas; 2, a four-way valve that has the function of reversing the flow direction of the refrigerant; 5, a pressure reducing device; 7, an accumulator to accumulate the excess refrigerant; 14, a refrigerating machine oil stored in the compressor 1, for effecting lubrication of the sliding portions of the compressor 1, and the sealing of a compression chamber; 52, a condenser for condensing a high pressure refrigerant gas discharged from the compressor 1; and 55, an evaporator. The refrigeration machine oil with a weak solubility, used in this "refrigeration and air-conditioning cycle apparatus, for example, alkylbenzene, has no solubility or only has a very weak solubility with respect to a hydrofluorocarbon-based refrigerant, being its ratio of solubility in the liquid refrigerant under the conditions of condensation pressure and condensation temperature of 0.5 to 7 percent by weight, its solubility ratio in the liquid refrigerant being under the conditions of evaporation pressure and evaporation temperature of 0 at 2.0 percent by weight, and its specific weight being on the temperature scale of -20 ° C to + 60 ° C, which is a value smaller than the specific weight of the liquid refrigerant at the same temperature and under a pressure of Saturated steam, a description of the behavior of the refrigerating machine oil will be given below. high pressure compressed by the compressor 1, discharge to the condenser 52. Most of the refrigerating machine oil 14 used to lubricate the compressor, and to seal the compression chamber, returns to the bottom of an airtight container, but the refrigerating machine oil having an oil circulation rate of 0.3 to 2.0 weight percent or around it, is discharged together with the refrigerant from the compressor 1. The diameter of the condenser tube 5, where the gas flows The refrigerant is set to ensure a sufficient flow rate of the refrigerant gas to transport the downstream refrigeration machine oil. Althomost of the refrigerant liquefies in the vicinity of an outlet of the condenser 52, and the flow velocity inside the tube declines appreciably, since the refrigerating machine oil has a weak solubility with respect to the condensed liquid refrigerant, the refrigerating machine oil dissolves in the liquid refrigerant, and is transported to the pressure reducing device 5. The temperature and pressure of the The refrigerant is declined appreciably in a region downstream of the pressure reducing device 5, and the solubility characteristic of the refrigerating machine oil changes until it has no solubility or until it has a very weak solubility with respect to the liquid refrigerant. However, the refrigerating machine oil transports to the accumulator 7, since the flow rate of the refrigerant increases abruptly due to the gasification of part of the liquid refrigerant, which occurs in the region downstream of the pressure reducing device. , and in that the diameter of the evaporator tube 55 in the next stage is set to ensure a flow rate of the refrigerant gas sufficient to transport the downstream refrigeration machine oil. Since the solubility of the refrigerating machine oil in the liquid refrigerant under the conditions of evaporating pressure and evaporating temperature is zero or very weak, the refrigerating machine oil 81 forms a separate layer on the liquid refrigerant 13 inside the accumulator 7. For this reason, the structure provided is such that a plurality of oil return orifices 72a, 72b, 72c, and 72d, which have different heights from a lower end 7a of the accumulator, are provided in an outlet tube 71, to drive the refrigerant from the inside to the outside of the accumulator, thus promoting the return of the oil to the compressor 1. As another example of the conventional refrigeration and air conditioning cycle apparatus, a cycle apparatus is shown in Figure 21. refrigeration and air conditioning disclosed in Japanese Patent Application Serial Number 19253/1989. In reference numeral 1 denotes the compressor to compress a refrigerant gas; 52, the condenser for condensing the high pressure refrigerant gas discharged from the compressor 1; 31, a pre-phase pressure reducing device; 6, a receiver to accumulate surplus refrigerant; 32, a post-phase pressure reducing device; 55, the evaporator, and 2, the four-way valve that has the function of reversing the flow direction of the refrigerant. Next, a description of the operation of this refrigeration and air conditioning cycle apparatus will be given. The high pressure refrigerant gas compressed by the compressor 1 passes through the condenser 52, while liquefying; it is then subjected to a pressure reduction by the pre-phase pressure reducing device 31, and enters the receiver 6. Here, by controlling the pressure reducing devices arranged respectively before and after the receiver 6, the excess refrigerant is accumulates in correspondence with the condition of the load of the device, optimizing in this way the operation and efficiency, and ensuring the reliability of the compressor. The liquid refrigerant 5 flowing outward from the receiver 6 is further subjected to a pressure reduction to the level of the necessary evaporation pressure, then passes through the evaporator 54, and is sucked into the compressor 1. * 10 Problems to be Resolved by the Invention In the refrigeration and air conditioning cycle apparatus shown in Figure 20, and cited as a conventional example using a hydrofluorocarbon (HFC) based refrigerant as a refrigerant, and a
oil based on alkylbenzene as a refrigerating machine oil, the following problem is encountered, in the case where a large amount of excess refrigerant is accumulated in the accumulator 7, and the liquid level becomes high. First, although the refrigerating machine oil 81 which can not be dissolved in the liquid refrigerant, is separated from the liquid refrigerant 13, and accumulates in an upper layer of the two separate layers, since the suction force from the holes higher 72c and
72d declines by comparing it with that from the hole 72a provided at a lower end of the outlet tube 71, between the oil holes 72 provided in the outlet tube 71 inside the accumulator 7, only the liquid refrigerant 13 of the lower layer flows towards inside the outlet pipe 71, and the cooling machine oil 81 of the upper layer scarcely flows into the outlet pipe 71. Accordingly, the cooling machine oil 81 accumulates in a large amount inside the accumulator 7, with the result that the refrigerating machine oil 81 in the compressor 1 runs out, possibly causing a failed lubrication. Next, when the liquid level of the liquid refrigerant becomes high, since the liquid refrigerant is sucked from the plurality of oil return orifices in the outlet tube 71, a large amount of liquid refrigerant returns to the compressor 1, which possible results in a sudden rise in pressure in the compression chamber, due to the supply of non-compressive liquid refrigerant to the interior of the compression chamber. In addition, since the liquid refrigerant discharged from the compression chamber stops in the hermetic container of the compressor, the liquid refrigerant, instead of the refrigerating machine oil 81, is supplied to the portions of the lubrication element, which it can cause an obstruction of the compressor bearing 1, and of the sliding portions of the compression elements, thereby leading to a decline in reliability. In addition, if the diameters of the oil return holes 72 are set small to prevent a large amount of refrigerant
liquid returns to the compressor 1, the return of the cooling machine oil 81 is further aggravated, and it is possible that dust, impurities, and the like in the circuit, plug the oil return holes 72. With the cycle apparatus cooling and
air conditioning shown in Figure 21, and cited as a conventional example, the apparatus can be operated without problems in a case where a refrigerating machine oil is used that has compatibility with a refrigerant, but if an oil is used of cooling machine that
does not have compatibility or has a weak compatibility, the refrigerating machine oil which is not soluble in the liquid refrigerant, separates in an upper layer, and stops inside the receiver 54 under the operating conditions where the circulation ratio of oil is
, and the refrigerating machine oil inside the compressor 1 is depleted, thus possibly causing a failed lubrication. In a conventional manner, when the tightness test is carried out in the manufacturing process of the
compressor using R.22 as a refrigerant, the discharge tube and the suction tube are closed by means of rigging, and the tightness test is carried out under the pressure of 28 kgf / cprG. However, in a case where a high pressure refrigerant such as R.410A is used as the hydrofluorocarbon (HFC) based refrigerant, the pressure corresponding to the refrigerant in the case of R.410A is considerably high, at 45 kgf / cm G, with the result that there is the possibility that the rigs will come off when the hermeticity test is carried out. The present invention has been devised to overcome the problems described above, and its object is to provide a highly reliable refrigeration and air conditioning apparatus, which is capable of reliably returning refrigerating machine oil, even in the case of
that a refrigerant circuit is provided, wherein the refrigerant and the refrigerating machine oil are
It is difficult to dissolve, and to be able to accumulate excess liquid refrigerant, so that a large amount of liquid refrigerant does not return to the compressor. Another object of
The present invention is to obtain an apparatus that is economical and highly reliable with a simple configuration.
Means for Overcoming Problems In accordance with the present invention, the refrigerant circulation apparatus 25, having a refrigerant circuit in which a compressor, a condenser, a pressure reducing device, and an evaporator are consecutively connected, by means of tubes of refrigerant, the refrigerant circulation apparatus comprises: a liquid storage container 5 connected between the condenser and the pressure reducing device, to allow the oil droplets to flow outward in a suspended form, by using a machine oil cooling that does not exhibit solubility or exhibits a
Very weak solubility in terms of a solubility by weight ratio of the refrigerating machine oil in a liquid refrigerant under conditions of condensing pressure and condensation temperature, and which does not exhibit solubility or exhibits a very weak solubility in terms of
a solubility by weight ratio of the refrigerating machine oil in the liquid refrigerant under conditions of evaporating pressure and evaporating temperature, and having a specific gravity smaller than the refrigerant.
The refrigerant circulation apparatus according to the present invention further comprises: an element for changing the flow direction of the refrigerant, the liquid accumulator container connecting to allow the oil droplets to flow outward in a form
suspended, between the condenser and the pressure reducing device, on a flow side where the coolant is exceeded. In accordance with the present invention, in the refrigerant circulation apparatus having a refrigerant circuit, where a compressor, an element for changing a flow direction of the refrigerant, a condenser, a pair of pressure reducing devices are consecutively connected. , and an evaporator, by means of refrigerant tubes, the refrigerant circulation apparatus comprises: a liquid storage vessel interposed between the pressure reducing devices, by using a refrigerating machine oil which does not exhibit solubility or exhibits a very high solubility. weak in terms of a weight ratio of the solubility of the refrigerating machine oil in a liquid refrigerant, under the conditions of condensation pressure and condensation temperature, and which does not exhibit solubility or exhibits a very weak solubility in terms of a in weight of the solubility of the oil ref machine rigeración in the liquid refrigerante, under the conditions of pressure of evaporation and temperature of evaporation. In the refrigerant circulation apparatus according to the present invention, refrigerant pipes are inserted into an inlet and outlet of the refrigerant, into and from the liquid storage tank, into the container, from a lower portion thereof. , and the refrigerant that is inside the liquid storage container is allowed to flow from bottom to top, and to agitate. In the refrigerant circulation apparatus according to the present invention, the refrigerant which is inside the liquid storage vessel is stirred by changing a phase state of the refrigerant, or a state of refrigerant.
W? pressure of the same, in a position where the refrigerant
flows in from an inlet tube of the liquid storage vessel, to accumulate excess refrigerant. The refrigerant circulation apparatus according to the present invention further comprises:
At least one subcooling detecting element, for detecting a characteristic subcooling value corresponding to a degree of subcooling of the refrigerant, at an output of the condenser, and a superheating detecting element, for detecting a value
characteristic of superheating corresponding to a degree of superheating of the refrigerant sucked into the compressor; a calculating element to calculate a deviation with a target value corresponding to at least one of a detection result by the
superheating detector element, and a result of the detection by the subcooling detector element; and a controlling element, for controlling a control valve of at least one of the pressure reducing devices on one side of high pressure and one side of low pressure, with 5 basis in the result of the calculation by means of the calculating element. In the refrigerant circulation apparatus according to the present invention, a valve is used
^ Control ß that can be controlled, such as the device
pressure reducer, and an area of an opening in the control valve that controls, such that the liquid refrigerant in the container becomes temporarily empty. In the refrigerant circulation apparatus according to the present invention, the valve is used
Controllable control, such as the pressure reducing device, and the control valve is controlled in a predetermined time after starting. The refrigerant circulation apparatus according to the present invention comprises: a refrigerant circuit, wherein consecutively a compressor, a condenser, a pair of pressure reducing devices, and an evaporator are connected, by means of refrigerant pipes; a liquid storage vessel provided in the refrigerant circuit, for accumulating a refrigerant, and an oil of | refrigeration machine that does not exhibit solubility or exhibits a very weak solubility in a liquid refrigerant under conditions of condensation pressure and condensation temperature, and under conditions of evaporation pressure and evaporation temperature with respect to the refrigerant circulating in the refrigerant circuit. refrigerant; and an element that establishes the oil solubility ratio to establish at least one of the temperature and pressure of the refrigerant in the liquid storage vessel, such
so that a solubility ratio of the refrigerating machine oil in the liquid refrigerant that is inside the liquid storage vessel, becomes approximately equivalent to, or higher than, an oil circulation rate of the machine oil.
cooling flowing out from the compressor to the refrigerant circuit during operation. In refrigerant circulation apparatus according to the present invention, pressure reducing devices are preferably disposed before and after
after the liquid storage vessel arranged in the refrigerant circuit, to accumulate the refrigerant, and the temperature and pressure of the refrigerant in the liquid storage vessel are established by the pressure reducing devices, in such a way that the ratio of
The solubility of the refrigerating machine oil in the liquid refrigerant that is inside the liquid storage vessel, becomes approximately equivalent to, or higher than, the rate of oil circulation of the cooling machine oil flowing out from the compressor to the refrigerant circuit during operation. In the refrigerant circulation apparatus according to the present invention, an element is used to make thinner oil droplets, such as at least one pre-phase pressure reducing device of the pressure reducing devices respectively disposed before and after the container liquid accumulator. The refrigerant circulation apparatus according to the present invention comprises: a refrigerant circuit in which a compressor, a condenser, a pressure reducing device, and an evaporator are consecutively connected, by means of refrigerant pipes; a liquid storage vessel provided in the refrigerant circuit, for accumulating a refrigerant and a refrigerating machine oil, which does not exhibit solubility, or which exhibits a very weak solubility in a liquid refrigerant, under conditions of condensation pressure and temperature. condensation, and under conditions of evaporation pressure and evaporation temperature with respect to the refrigerant circulating in the refrigerant circuit; and an oil recovery element disposed in an interior of the compressor, or on a discharge side of the compressor, to lower an oil circulation rate, such that the oil circulation rate of the cooling machine oil flowing outwardly from the compressor to the refrigerant circuit during operation becomes approximately equivalent to, or lower than, a ratio in which the liquid refrigerant that is inside the liquid storage vessel dissolves the refrigerating machine oil. In the refrigerant circulation apparatus according to the present invention, an inlet tube is configured for the refrigerant to flow into the liquid storage vessel from the refrigerant circuit, and an outlet tube for the refrigerant to flow from the liquid storage vessel towards the refrigerant circuit, with its respective tube openings disposed in a lower portion of the liquid storage container, and configured to allow the refrigerant to flow directly from the inlet tube to the outlet tube. The refrigerant circulation apparatus according to the present invention further comprises: a coupling portion disposed on a tube on the discharge side of the compressor, and having an external diameter fBβ changed from the tube. In the refrigerant circulation apparatus according to the present invention, the refrigerating machine oil has no solubility or has a very high solubility.
weak with respect to the refrigerant, its ratio by weight of solubility in the liquid refrigerant under the conditions of condensation pressure and condensation temperature being 0.5 to 7 percent by weight, and being its
Wf weight ratio of solubility in the liquid refrigerant
under the conditions of evaporation pressure and evaporation temperature from 0 to 2.0 percent by weight. The method for assembling a refrigerant circuit in accordance with the present invention comprises the steps of: providing, in the refrigerant circuit, an element
liquid accumulator for accumulating a refrigerant circulating in a refrigerant circuit, where a compressor, a condenser, a pressure reducing device, and an evaporator are consecutively connected, by means of refrigerant tubes; seal, in the refrigerant circuit, a
refrigerating machine oil which does not exhibit solubility or which exhibits a very weak solubility in a liquid refrigerant under conditions of condensation pressure and condensation temperature, and under conditions of evaporation pressure and evaporation temperature; and establish when
minus one of the temperature and pressure of the refrigerant in the liquid storage element, such that a solubility ratio of the refrigerating machine oil in the liquid refrigerant inside the liquid storage element becomes approximately equivalent to, or higher than, a rate of oil circulation from the cooling machine oil flowing out from the compressor to the refrigerant circuit during operation. The method for assembling a refrigerant circuit in accordance with the present invention comprises the steps of: changing a class of refrigerant to be circulated in a refrigerant circuit, where a compressor, a condenser, a reducing device, are consecutively connected. pressure, an evaporator, and a liquid storage element for accumulating a refrigerant, by means of refrigerant pipes, from a sealed refrigerant to another refrigerant; continue to seal the refrigeration machine oil sealed in the compressor, even when changing the refrigerant class; and setting at least one of the temperature and pressure of the refrigerant in the liquid storage element, such that a solubility ratio of the refrigerating machine oil in the changed refrigerant becomes approximately equivalent to, or higher than, a ratio of oil circulation of the cooling machine oil flowing out? from the compressor to the refrigerant circuit during operation, in a case where the solubility ratio of the refrigerating machine oil is lower than the oil circulation rate. 5 Modalities of the Invention
First Modality Referring now to Figures 1 a and 2,
will give a description of a first embodiment of the present invention. Figure 1 shows an example of a refrigerant circulation apparatus that is applied to an air conditioner. In Figure 1, the reference numeral 1 denotes a compressor for compressing a refrigerant gas; 4, a
external heat exchanger for condensing the high pressure refrigerant gas discharged from the compressor 1; 3, an internal heat exchanger; 5, a pressure reducing device; and 6 a liquid storage vessel for accumulating surplus refrigerant. In addition, the
Figure 2 shows the structure of the liquid storage container where the numeral 7 denotes a main body of the liquid storage container; 8, an input tube connected to the underside of the container; and 9, an outlet tube connected to the upper side of the container. The
numerals 16 and 17 denote fans for internal and external heat exchangers, respectively. A description will be given below of the behavior of the refrigerant and the refrigerating machine oil, in a case where the refrigerant flows in the direction of the arrows. The high pressure refrigerant gas compressed by the compressor 1, is discharged together with the refrigerating machine oil, which has a weight ratio of 2.0 percent with respect to the refrigerant, and enters the external heat exchanger 4, which is a condenser to condense the refrigerant. The refrigerating machine oil is transported in the external heat exchanger 4 by the refrigerant gas, which has a sufficient flow rate. In the vicinity of the outlet gate of the external heat exchanger 4, part of the refrigerating machine oil dissolves in the liquefied refrigerant, while the remaining portion of the refrigerating machine oil is transformed into oil droplets, in such a way that the refrigerating machine oil is transported to the liquid storage vessel 6 together with the refrigerant. In the main body 7 of the liquid storage vessel, where the channel area becomes large, the flow rate of the liquid refrigerant declines, and the refrigerating machine oil which is in the form of oil droplets, floats towards up in the container, since its specific weight is | ^ smaller than that of the refrigerant. However, the direction in which the cooling machine oil floats upwards is the same as the direction of coolant flow, as indicated by the arrows, and the main body 7 of the container is generally in a state of being. filling with the liquid, with the exception of a period immediately after the start (for approximately 5 minutes), in such a way that the refrigerating machine oil is transported from the outlet pipe
9 out of the container without stopping in the main body 7 of the liquid storage container. Since part of the liquid refrigerant is gasified by undergoing a pressure reduction to a necessary level of pressure, by means of the pressure reducing device 5, the
The amount of refrigerant that is present in liquid form, such that the refrigerating machine oil that dissolves in the gasified liquid refrigerant separates and forms droplets of oil. However, since the flow rate of the refrigerant increases abruptly due to the
gasification of part of the liquid refrigerant, and the diameter of the tube of the internal heat exchanger 3 which is an evaporator in the next phase to evaporate the refrigerant, is established to ensure a sufficient flow rate of the refrigerant gas to transport the machine oil
refrigeration downstream, the machine oil of jBg) refrigeration is transported through the internal heat exchanger, and returns to compressor 1. Accordingly, the refrigerating machine oil that flowed out from the compressor, can be returned reliably to
compressor, and proper lubrication and sealing functions can be maintained for the compression elements, in such a way that it is possible to obtain an apparatus where the reliability of the compressor is high. In addition, the structure is simple jBM, the productivity and operation for the cost are
outstanding, and there is no decline in performance due to dust clogging.
Second Modality Referring now to Figures 2 and 3,
will give a description of a second embodiment of the present invention. Figure 3 shows an example of a refrigerant circulation apparatus that is applied to an air conditioner. In Figure 3, the reference numeral 1 denotes the compressor for compressing a refrigerant gas; 2, a valve
four-way that has the function of reversing the flow direction of the refrigerant; 18, an extension tube that connects an internal unit with an external unit; 3, the internal heat exchanger; 4, the external heat exchanger; 5, the pressure reducing device; and 6, the
liquid storage vessel to accumulate excess refrigerant. In addition, Figure 2 shows the structure of the liquid storage container, wherein the numeral 7 denotes the main body of the liquid storage container; 8, the inlet tube connected to the underside of the container; and 9, the outlet tube connected to the upper side of the container. A description will be given below of the behavior of the refrigerant and the refrigerating machine oil, in a case where the heating is carried out by the internal unit. The high-pressure refrigerant gas compressed by the compressor 1 is discharged together with the refrigerating machine oil, which has a weight ratio of 2.0 percent with respect to the refrigerant, passes through the four-way valve 2, and it enters the internal heat exchanger 3 which is a condenser. The refrigerating machine oil is transported by the refrigerant gas, which has a sufficient flow rate, and part of the refrigerating machine oil is dissolved in the liquefied liquid refrigerant in the vicinity of the outlet gate of the internal heat exchanger 3 , while the remaining portion of the refrigerating machine oil is transformed into oil droplets, such that the refrigerating machine oil is transported to the liquid storage vessel 6, together with the refrigerant. In the main body 7 of the liquid storage vessel, where the channel area becomes large, the flow rate of the liquid refrigerant declines, and the refrigerating machine oil, which is in the form of oil droplets, floats up in the container, since its specific weight is smaller than that of the refrigerant. However, the direction in which the cooling machine oil floats upwards is the same as the direction of coolant flow, as indicated by the arrows, and the main body 7 of the container is generally in a state of being filled with the liquid, with the exception of a period immediately after starting (for approximately 5 minutes), so that the refrigerating machine oil is transported from the outlet tube 9 to the outside of the container without stopping in the container . In accordance with the above, the refrigerating machine oil is transported to the pressure reducing device 5 without stopping in the main body 7 of the liquid storage vessel. Since part of the liquid refrigerant is gasified by undergoing a pressure reduction, up to a necessary pressure level, by means of the pressure reducing device 5, the amount of refrigerant that is present in liquid form is reduced, in such a way that the oil The cooling machine that dissolves in the gasified liquid refrigerant separates and forms droplets of oil. However, since the coolant flow rate increases abruptly due to the gasification of the liquid refrigerant part, and the pipe diameter of the external heat exchanger 4, which is an evaporator, in the next phase, is set to ensure a flow velocity of the refrigerant gas, sufficient to transport the refrigerating machine oil downstream, the refrigerating machine oil is transported through the external heat exchanger, and returns to the compressor 1. In the case of heating, that the internal heat exchanger generally becomes smaller than the external heat exchanger, the amount of refrigerant may be smaller than in the case of cooling, such that excess refrigerant may be present. On the other hand, in the case where the cooling is effected by the internal unit, by allowing the refrigerant to flow inversely, changing over the four-way valve, the condensing and evaporation papers are exchanged through the internal heat exchangers and external, and the refrigerant, where part of the refrigerant is gasified due to the reduction of pressure by the pressure reducing device 5, and the liquid and gas, are mixed, and flow from the outlet tube 9 to the body H ^ main 7 of the container. However, since the refrigerant flows from top to bottom through the container, the refrigerating machine oil is transported from the inlet tube 8 to the outside of the container.
container without staying there. For this reason, in the case of cooling where refrigerant is used in a large quantity, even if the liquid storage tank stops functioning as the liquid storage vessel, there is no
Wf need him, and the refrigerating machine oil that
is transported together with the refrigerant, it is transported without stopping in the container. Consequently, the refrigerating machine oil discharged from the compressor 1, returns to the compressor 1 without stopping during the cycle. As described above, since the
excess refrigerant can accumulate, even when the required amount of refrigerant differs due to the direction of flow, it is possible to operate the apparatus in an efficient manner, regardless of the flow direction. At the same time, the cooling machine oil that flowed
out of the compressor, the compressor can be returned reliably, and proper lubrication and sealing functions can be maintained for the compression elements, so that it is possible to obtain an apparatus where the reliability of the compressor is high.
Third Modality Referring now to Figure 4, a description of a third embodiment of the present invention will be given. Figure 4 shows an example of the refrigerant circulation apparatus, which is applied to an air conditioner. In Figure 4, the reference numeral 1 denotes the compressor for compressing a refrigerant gas; 2, the four-way valve that has the function of reversing the flow direction of the refrigerant; 4, the external heat exchanger; 16,
# 10 an internal fan; 3, the internal heat exchanger; 17, an external fan; 5a and 5b, the pressure reducing devices; and 6, the liquid storage container for accumulating excess refrigerant. A description of the
behavior of refrigerant and refrigerating machine oil. The high pressure refrigerant gas compressed by the compressor 1, is discharged together with the refrigerating machine oil, which has a weight ratio of, for example, 1.0 percent, with respect to the refrigerant, passes
through the four-way valve 2, and enters the internal heat exchanger 3, which is a condenser. The refrigerating machine oil is transported by the refrigerant gas, which has a sufficient flow rate, and the refrigerating machine oil is
dissolves completely in the liquefied liquid refrigerant in the vicinity of the outlet port of the internal heat exchanger 3. However, in the case of an oil based on alkylbenzene, the solubility limit of the refrigerating machine oil in a low refrigerant The conditions of condensation pressure and condensation temperature, is around 1.5 percent. The refrigerating machine oil, together with the refrigerant, passes through the pressure reducing device 5b and is transported to the liquid storage container 6. The declines in pressure and temperature of the pressure reducing device 5a are established in scales where the solubility limit does not reach less than 1 percent, thus allowing the refrigerating machine oil to be transported out of the container, as it dissolves in the refrigerant, without being separated from the refrigerant. refrigerant inside the liquid storage vessel 6. According to the above, the refrigerating machine oil is transported to the pressure reducing device 5b without stopping in the liquid storage vessel 6. Since the pressure inside the pressure reducing device 5b is reduced to a necessary pressure level, and the temperature declines abruptly, the solubility limit of the The temperature of the refrigerating machine in the liquid refrigerant declines to 0.5 percent, with the result that the refrigerating machine oil that can not be dissolved in the liquid refrigerant, separates and forms droplets of oil. In addition, in the external heat exchanger 4, most of the refrigerant is gasified, and the amount of refrigerant that
is present in liquid form declines, in such a way that the refrigerating machine oil that can not be dissolved, separates. After the refrigerant leaves the pressure reducing device, however, since the
Wß flow velocity of the refrigerant, due to its gasification,
assumes a sufficient level to transport the separated refrigerating machine oil downstream, the refrigerating machine oil is conveyed to the compressor 1. In addition, the same applies to a case where the flow direction is reversed by the valve
four ways. In general, if a liquid collection section is provided in a refrigerant circuit, and if a refrigerating machine oil is used that is difficult to dissolve in a refrigerant using hydrofluorocarbon,
such as a refrigerating machine oil, alkylbenzene, a mineral oil, an ester oil, an ether oil, or the like, which has no solubility or which has a very weak solubility with respect to, for example, a refrigerant based on hydrofluorocarbon, its weight ratio being
Solubility in the liquid refrigerant under the conditions of condensation pressure and condensation temperature of 0.5 to 7 weight percent, and its solubility by weight ratio in the liquid refrigerant under the conditions of evaporation pressure and evaporation temperature of the liquid refrigerant. 0 to 0.20 percent by weight, then the oil that is mixed with the refrigerant is stopped inside the container in the refrigerant circuit that has the liquid collection section, ie the liquid storage tank to accumulate the surplus refrigerant , where the speed of movement of the refrigerant becomes slower. The weight ratio of solubility of the oil in the refrigerant, first, changes depending on the kind of refrigerant and oil. For example, in terms of the solubility ratio of the alkylbenzene cooling machine oil (viscosity grade VG = 8 -32), ie, a HAB oil in the liquid refrigerant R.407C, i.e., a refrigerant based on hydrofluorocarbon, as well as the ratio between the oil circulation speed and the compressor frequency, the refrigerating machine oil exhibits a solubility ratio of 1.0 to 4.0 percent by weight with respect to the liquid refrigerant in the temperature scale of condensation, but exhibits a very small solubility ratio of 0.2 to 1.8 percent by weight with respect to the liquid refrigerant on the scale of the evaporation temperature. This solubility ratio changes depending on the combinations of different refrigerants and different oils. In general, the oil circulation velocity, that is, a weight ratio of the refrigerating machine oil flowing with the refrigerant from the compressor to the refrigerant, assumes a value of about 0.3 to 2.0 percent by weight, and tends to to increase with the increase of the compressor frequency. The refrigerating machine oil circulates in the refrigerant circuit in an amount that is shown by this oil circulation speed, and is particularly susceptible to being stopped in the liquid storage vessel, and the refrigerating machine oil dissolves in the liquid refrigerant inside the container within the scale of its solubility ratio at that temperature. However, in a case where the oil circulation velocity has become higher than the solubility ratio of the refrigerating machine oil in the liquid refrigerant under the operating conditions in the place, where the refrigerant is present, the The amount of refrigerating machine oil circulated exceeds a permissible amount of dissolution in the liquid refrigerant. In consecuense, the refrigerating machine oil separates from the liquid refrigerant, assumes the state of oil droplets or of an oil layer in the liquid storage container, stops in the liquid storage container, and does not return to the compressor. In contrast, for example, if the temperature of the liquid refrigerant in the container is detected by a thermistor, and the pressure reducing device 5a is set to move in the closing direction when the temperature of the refrigerant has become lower than the temperature of the refrigerant. temperature necessary for the dissolution of the oil, the Wj >; possible to dissolve the oil. 10 It goes without saying that, instead of using electrically operated expansion valves that can be controlled, such as pressure reducing devices, devices can be provided from the beginning by using capillary tubes, to suppress the limit
below the temperature and the lower limit of the pressure inside the liquid storage tank, in fixed values, under the different operating conditions. Although the above description has been given by citing the hydrofluorocarbon-based coolant as an example, the
The present invention is not limited thereto, and it can be seen that similar advantages can be obtained if a refrigerating machine oil which is difficult to dissolve in the refrigerant is used, even when a hydrocarbon-based refrigerant is used. 25 In case where the operating frequency of the compressor is low, the condensation temperature declines, and the solubility ratio of the refrigerating machine oil in the refrigerant declines, but, since the amount of cooling machine oil that is discharged since the compressor also decreases at the same time, all the cooling machine oil that is circulated can be dissolved in the refrigerant, in the liquid storage tank 6. As described above, since it can be
• stop excess refrigerant in the liquid reservoir,
in both directions of flow, for cooling and heating, the operation can be effected in an efficient manner, and the refrigerating machine oil can be returned to the compressor without stopping in the liquid storage vessel. Therefore, it is possible to obtain an apparatus in
where the reliability of the compressor is high. The present invention in accordance with this embodiment is particularly effective for a multi-type air conditioner having a plurality of internal units, and wherein the required amount of
refrigerant depending on the number of internal units operated under the respective operating conditions for cooling and heating.
Fourth Mode 25 Referring now to Figures 4, 5, and 6, a description of a fourth embodiment of the present invention will be given. Figure 5 shows the structure of the liquid storage container, where an inlet pipe 11 and an outlet pipe 12 are inserted in a liquid storage tank from a lower surface thereof, and open towards the upper portion of the container . In addition, the inserted section of the inlet tube 11 and the outlet tube 12 is 5 millimeters, and the external diameter of both tubes is 9.52 millimeters. 10 A description of the behavior of the refrigerant and the refrigerating machine oil will be given below. During the continuous state operation, the high pressure refrigerant gas compressed by the compressor 1 is discharged together with the refrigerating machine oil,
having a weight ratio of, for example, 1.0 percent with respect to the refrigerant, passing through the four-way valve 2, and entering the internal heat exchanger 3, which is a condenser. The refrigerating machine oil is transported by the refrigerant gas, which
has a sufficient flow velocity, and the refrigerating machine oil is completely dissolved in the liquid liquefied refrigerant in the vicinity of the outlet port of the internal heat exchanger 3. In contrast, during the start-up of the compressor 1, there are cases where is
temporarily discharges 2 percent or more of the refrigerating machine oil, along with the refrigerant gas. In this case, the refrigerating machine oil which did not dissolve in the liquid refrigerant inside the internal heat exchanger 3, assumes the state of oil droplets, and is transported to the liquid storage vessel, together with the liquid refrigerant. However, the solubility limit of the refrigerating machine oil in the refrigerant under the conditions of condensing pressure and condensing temperature is about 1.5 percent. Since the flow velocity of the liquid refrigerant that flowed into the container 10 from the inlet tube 11 lowers, the droplets of oil that flowed into the container along with the liquid refrigerant float upwards, and form an oil layer 14. Then, when the operating state is stabilized, and the discharge rate of the refrigerating machine oil decreases to a level below the solubility ratio of the refrigerating machine oil in the refrigerant under the pressure and temperature conditions inside the vessel 10, the oil in the oil layer 14 is dissolved in the refrigerant 13 in the vessel, and the thickness of the the oil layer 14 gradually decreases. The change in the thickness of the oil layer 14 after the start of the compressor is shown in Figure 6. In connection with this, a distribution in the dissolved concentration of the refrigerating machine oil in the liquid refrigerant 10 inside the container 10, and the closer it is to oil layer 14, the higher the concentration. In contrast, since the inlet tube 11 provided in the lower portion of the container is open from below in the upward direction, towards the oil layer 14, the flow of the refrigerant which has flowed impacts the lower surface of the oil layer 14, so that the oil layer 14 is agitated with the refrigerant 13, and the refrigerant 13 is also stirred at the same time. For this reason, the concentration of the cooling machine oil in the coolant 13, which is contiguous with the oil layer 14, decreases, and the dissolution of the cooling machine oil in the oil layer 14 in the coolant 13 is promoted. The dissolved oil is transported out of the container together with the refrigerant, from the outlet pipe provided in the lower portion of the container, and returns to the compressor. It should be noted that even when an oil that is heavier than the refrigerant is used, the oil can be dissolved in the refrigerant by virtue of the structure described above, and of the stirring operation, which is effective in returning the oil to the oil. compressor.
Fifth Mode Referring now to Figure 7, a description of a fifth embodiment of the present invention will be given. Figure 7 is a diagram illustrating a schematic structure of an embodiment of the refrigerant circulation apparatus in accordance with the present invention. In Figure 5, the reference numeral 1 denotes the compressor to compress a refrigerant gas; 2, the four-way valve that has the function of reversing the flow direction of the refrigerant, establishing the four-way valve in the? position for the heating operation in the case
illustrated; 4, the external heat exchanger for condensing the high pressure refrigerant gas discharged from the compressor 1; 16, the internal fan; 3, the internal heat exchanger; 17, the external fan; 5a and 5b, the pressure reducing devices; 6, the container
liquid accumulator to accumulate excess refrigerant; 18, the extension tube that connects the internal unit and the external unit; 19, a pressure sensing element; 20, a temperature sensing element, for detecting the exit temperature of the internal heat exchanger; 21, an element
temperature detector for detecting the inlet temperature of the external heat exchanger; 22, a temperature sensing element for detecting the suction temperature of the compressor; and 23, a calculating and control device, to control the areas of the openings of the
pressure reducing devices 15a and 15b, based on the data detected by the detector elements 19 to 22. In the refrigerant circulation apparatus according to the present invention, it is assumed that the areas of the openings of the reducing devices of pressure 15a and 15b are being controlled to certain areas, that the liquid refrigerant accumulates in the liquid storage vessel 6, and that the level of the accumulated liquid is maintained in a stable state. At this time, the pressure of the coolant in the channels, including the liquid storage vessel between the pressure reducing devices 15a and 15b, is at a level between the condensing pressure and the evaporating pressure, and at the so-called intermediate pressure, and the liquid refrigerant that accumulates in the liquid storage vessel 6 is in a saturated state. Incidentally, the degree of superheating of the refrigerant sucked into the compressor, is determined from the respective temperatures detected by the detector element 22, to detect the temperature of the refrigerant sucked into the compressor, and the detector element 21 to detect the temperature input of the external heat exchanger, as the deviation between temperatures is calculated by the calculating and controlling device 23. Incidentally, this deviation will be referred to as the degree of superheating.
On the other hand, the degree of subcooling at the outlet of the internal heat exchanger is determined when the calculating and controlling device 23 calculates the difference between, on the one hand, the saturation temperature of the refrigerant corresponding to the pressure detected by the element. pressure detector 19, and on the other hand, the detection temperature detected by the detector element 20, to detect the temperature of the refrigerant at the outlet of the internal heat exchanger. In an incidental manner, this deviation will be referred to as the degree of subcooling. It should be noted that the subcooling detector element for detecting a subcooling characteristic corresponding to the degree of subcooling of the coolant at the outlet of the internal heat exchanger is constituted by a combination, on the one hand, of the detector element 20 for detecting the coolant temperature at the outlet of the internal heat exchanger, and on the other hand, of a detector element (not shown) for detecting the temperature at the center of the internal heat exchanger, to detect the temperature in the vicinity of the center of the internal heat exchanger, which is equivalent to the saturation temperature of the refrigerant corresponding to the pressure detected by the pressure detecting element 19. In an alternative manner, the
Asuí. if i-J .. nn. H n -v ---- ^. i -.t- ^ t- • Wk deviation between the coolant temperature in the vicinity of the center of the internal heat exchanger and the temperature of the coolant at the outlet of the internal heat exchanger, can be set as the degree of
subcooling. Meanwhile, the subcooling detecting element for detecting a characteristic subcooling value corresponding to the degree of superheating - of the suction refrigerant of the compressor, is constituted
by a combination of a detector element (not shown) for detecting the outlet temperature of the external heat exchanger in order to detect the temperature of the refrigerant at the outlet of the external heat exchanger, and the detector element 21, for detecting the entry temperature
of the external heat exchanger, in order to detect the temperature of the refrigerant at the inlet of the heat exchanger. Alternatively, the deviation between the outlet and inlet temperatures in the external heat exchanger can be established as the
degree of superheating. Here, if the pressure reducing device of the high pressure side 15a is drowned, the pressure at the outlet of the pressure reducing device 15a is lowered, and the refrigerant assumes the state of two gas-liquid phases, and flows towards the
liquid storage container 6. At this time, since * the gaseous refrigerant and the liquid refrigerant are respectively separated in an upper portion and a lower portion in the liquid storage container 6 due to the action of gravity, if they are arranged both the inlet pipe 5 and the outlet pipe of the liquid storage tank 6 in the lower portion of the liquid storage tank, only the liquid refrigerant is always sent to the pressure reducing device
# 15b. In addition, the gasified refrigerant reduces the
liquid refrigerant inside the liquid storage vessel 6, due to the conversion of two gas-liquid phases of the refrigerant, thus lowering the liquid level. Then, since the liquid refrigerant that is released from the liquid storage vessel 6 during the
refrigeration cycle is stopped at the output of the internal heat exchanger 3, the degree of superheating becomes large during the refrigeration cycle. For this reason, the temperature of the
refrigerant in the liquid storage vessel 6, and declines the solubility of the refrigerating machine oil in the refrigerant. On the other hand, if the pressure reducing device of the high pressure side 15a is opened to the contrary, a change occurs which is opposite to the case of
drowning, and the liquid level rises, while the temperature of the refrigerant in the liquid storage vessel 6 rises, and the solubility ratio of the refrigerating machine oil in the refrigerant increases. Therefore, it is sufficient that the area of the opening in the valve device of the high pressure side be increased or decreased in correspondence with the objective values that are established according to the operating condition and the surrounding environment, is say, ^ P in correspondence with the objective establishments of the 10 degree of subcooling that are established to allow the operation of the air conditioner to be fully demonstrated according to the temperature of the external air and the temperature set inside. Therefore, by controlling the
pressure reducing device of the high pressure side 15a in the manner described above, it is possible to control the degree of subcooling and the temperature of the refrigerant in the liquid storage vessel.
Sixth Mode Meanwhile, if the pressure reducing device of the low pressure side 15b is opened, the pressure at the outlet of the pressure reducing device of the high pressure side 15a decreases, and the refrigerant assumes the state of two phases of
liquid gas, and flows into the liquid storage container ^ 6. At this time, since the gaseous refrigerant and the liquid refrigerant are respectively separated in an upper portion and a lower portion in the liquid storage vessel 6 due to the action of gravity, if
, both the inlet tube and the outlet pipe of the liquid storage container 6 are arranged in the lower portion of the liquid storage container, only the liquid refrigerant is always sent to the pressure reducing device ßr 15b. In addition, the gasified refrigerant reduces
to the liquid refrigerant inside the liquid storage vessel 6 due to the conversion of two gas-liquid phases of the refrigerant, thus lowering the liquid level. Then, since the coolant flow rate increases at the output of the device
pressure reducer on the low pressure side 15b, the degree of superheating in the suction of the compressor declines. If the pressure reducing device of the low pressure side 15b is choked, on the other hand, the degree of superheating in the suction of the compressor is increased. Therefore, it is sufficient that the area of the opening in the valve device of the low pressure side be increased or decreased in correspondence with the objective values that are established according to the operating condition in the surrounding environment, ie , in correspondence with the objective establishments of the superheating degree that is established, to allow the operation of the air conditioner to be fully demonstrated in accordance with the temperature of the outside air and the established interior temperature. Accordingly, by controlling the pressure reducing device of the low pressure side 15b in the manner described above, to control the degree of superheating in the suction of the compressor, that is, the dry fraction, at an optimum value, it is possible further expand the available pressure and temperature, thereby making it possible to make the apparatus efficient, and maintain an operating condition that requires less energy.
Seventh Mode In addition, by controlling the pressure reducing device of the high pressure side 15a and of the pressure reducing device of the low pressure side 15b in an interlocked manner, the degree of control can be controlled.
subcooling and the degree of superheating in predetermined values, thus making it possible to maintain an operating state where the input energy is small. This can be an operation with a minimum of energy under the given conditions. Eighth Modality Referring now to Figures 5 and 7, a description of another embodiment of the present invention will be given. Electrically operated expansion valves are used, which are controlled by a microcomputer, such as pressure reducing devices 15a and 15b, as shown in Figure 7. Then, control is provided, such that the pressure ratio and the temperature inside the liquid storage vessel assumes a saturated state. In this state, if control is provided such that the area of the opening in the expansion valve of the inlet side 15a becomes small, and the area of the opening in the expansion valve of the outlet side 15b becomes large, the state of the refrigerant passing through the inlet tube 11 shown in Figure 5, changes from that of saturated liquid to the two-phase gas-liquid state. As a result, bubbles are produced from the inlet tube 11, and the bubbles thus produced agitate the refrigerant 13 while they rise through the refrigerant 13 inside the container, and when they reach the oil layer 14, they agitate the oil layer 14 and refrigerant 13. If this condition continues, the amount of refrigerant accumulated in the container decreases, so that, after the passage of a certain duration of time, the areas of the openings in the expansion valves 15a and 15b are controlled, in such a way that the state of the refrigerant in the inlet tube 11 becomes that of the subcooled liquid. Accordingly, as bubbles occur in the container, and that the refrigerant 13 and the oil layer 14 are agitated by bubbles, the dissolution of the refrigerating machine oil stopped in the refrigerant is promoted. Although a description of the case has been given in
Where the agitation is effected by the production of bubbles, the agitation can be effected by a change in the flow velocity accompanying a change in pressure. This control can be appropriately provided, for example, for each fixed time or each operating time of the
compressor during operation, or by the fact that the oil has accumulated in the container that can be detected by detecting the temperature at the top of the container. It should be noted that, as a change that is imparted to
refrigerant, a description has been given of the case where the change is imparted by pressure reducing devices, but the condition of the refrigerant can be changed by different methods, such as one wherein a change circuit is provided in an outlet portion. of the tube
entry, and pressure changes * are repeatedly imparted using a hole.
Ninth Modality Referring now to Figures 5 and 7, a description of another embodiment of the present invention will be given. Electrically operated expansion valves are used, which are controlled by a microcomputer, such as pressure reducing devices 15a and 15b, as shown in Figure 7. Then, control is provided,
so that the relationship between pressure and temperature inside the liquid storage vessel assumes a saturated state. In this state, if control is provided such that the area of the opening in the expansion valve on the inlet side 15a becomes small, and the area
of the opening in the outlet side expansion valve
15b becomes large, the state of the refrigerant passing through the inlet tube 11 shown in Figure 5, changes from that of saturated liquid to the two-phase gas-liquid state. In this state, gradually decreases the
refrigerant 13 in the container, and this state continues until the refrigerant 13 is exhausted. Subsequently, the expansion valves are controlled, such that the state of the refrigerant in the inlet tube 11 becomes that of the subcooled liquid, to accumulate the refrigerant
again. When the liquid level of the | refrigerant 13, the oil layer 14 is transported from the outlet tube 12 to the outside of the container. Then, when the refrigerating machine oil has been transported out of the container, a
control to accumulate the refrigerant inside the container. If this control is carried out once at the moment when the thickness of the oil layer is under the condition of being large inside the container after starting the
- m compressor, it is possible to transport it out of the container
the refrigerating machine oil that stops inside the container, and return it to the compressor. Incidentally, the presence or absence of the liquid level can be detected by detecting the temperature at the top of the container. 15 As described above, it becomes possible to realize a circuit and a method of control that does not
'stop the oil in the container, even when using an oil that is difficult to dissolve in a refrigerant, and when an accumulator container is provided
of liquid, such as a receiver, an accumulator, or a head, in the refrigerant circuit. As a result, it is possible to return the refrigerating machine oil reliably to the compressor without stopping a large quantity of oil in the liquid storage vessel, the
suitable sealed lubrication functions for the interior 9 of the compressor, and it is possible to reliably maintain proper operation for the condition of the load by accumulating surplus refrigerant in the refrigerant circuit. In addition, the excess refrigerant can accumulate in correspondence with the flow direction of the refrigerant in the apparatus, and it becomes possible to make full use of the capabilities of the apparatus and operate the apparatus in a flexible manner. In addition, it becomes possible to prevent the excess refrigerant from flowing to the compressor, thus making it possible to improve the reliability of the compressor. In addition, in accordance with the present invention, the liquid refrigerant may accumulate in the liquid reservoir without accumulating the oil, or the refrigerant
The liquid can be emptied from the liquid reservoir, and an optimum operating state can be established during start-up or in correspondence with the condition of the load as long as the reliability of the compressor is maintained. In addition, even when the oil is temporarily stopped in the container
liquid accumulator, it is possible to return the oil quickly to the compressor, or reduce the amount of oil stopped, causing the oil to dissolve gradually in the refrigerant, without exerting an effect on the operational operation. It is possible to promote the dissolution of the oil in the
refrigerant, by stirring the refrigerant inside the container, making use of the speed of the refrigerant flowing into the container, and it is possible to reliably carry out the conversion of the oil without impairing the reliability of the compressor. It should be noted that it is possible to adopt a structure to facilitate agitation, by forming the liquid storage vessel in a narrow and deep configuration. Furthermore, in a case where the flow velocity
of the refrigerant flowing into the container is slow, and the stirring effect is small, the dissolution of the oil in the refrigerant can be promoted by changing the state of the refrigerant inside the container.
Tenth Mode Referring now to Figures 8, 9, and 10, a description of a tenth embodiment of the present invention will be given. Figure 8 shows a configuration of a refrigerant circuit 20 for circulating the refrigerant in the refrigeration and air conditioning apparatus, wherein the reference numeral 1 denotes the compressor; 52, a capacitor; 54, a receiver (storage tank of liquefied) to accumulate excess refrigerant; 55, an evaporator; 32, an opening / closing valve, which is a pressure reducing device for reducing the pressure of the refrigerant on the high pressure side; 100, a thermistor for detecting the temperature of the interior of the receiver 4 in a saturated state; 101, a muffler that is part of the compressor 1, 5 to delay the flow of the refrigerant; and 102, a fan for the condenser. In Figure 8, if the refrigerant circuit is for an air conditioner as shown in Figure 9,
«P in Figure 9, reference numeral 121 denotes a unit
external that incorporates therein the heat exchanger 52, that is, the condenser, the electrical components 125, the compressor 1, and the receiver 54; 122, an internal unit having the heat exchanger 55, i.e., the evaporator, the electrical components 126 and a ventilation damper
123; and 124, an extension tube for circulating the refrigerant between the outdoor unit 121 and the indoor unit 12. fjß Figure 9 (a) corresponds to a normal ambient air conditioner, where an indoor unit 122 is provided for an outdoor unit 121, while the
Figure 9 (b) shows an example of the multi-type air conditioner, wherein a plurality of internal units are provided for an external unit 121. The refrigerant, which is compressed by the compressor 1, is condensed by the condenser 52, undergoes a
pressure reduction by the opening / closing expansion valve 32, is evaporated by the evaporator 55, and is returned to the compressor 1. The refrigerating machine oil, as lubricating oil for the sliding portions of the compressor, is stored in the compressor 1. Although a very small amount of refrigerating machine oil flows out of the compressor into the refrigerant circuit along with the refrigerant, if a refrigerating machine oil is used that dissolves poorly in a refrigerant using hydrofluorocarbon, such as a refrigerating machine oil, alkylbenzene, a mineral oil, an ester oil, an ether oil, or the like, which has no solubility or which has a very weak solubility with respect to, for example, a hydrofluorocarbon-based refrigerant, with its weight ratio of solubility in the liquid refrigerant under the pressure conditions of condensation and condensation temperature between 0.5 and 7 percent by weight, and its weight ratio of solubility in the liquid refrigerant under the conditions of evaporation pressure and evaporation temperature between 0 and 0.20 percent by weight, then the refrigerating machine oil that is mixed with the refrigerant is stopped inside the receiver in the refrigerant circuit that has the liquid collection section, that is, the receiver to accumulate the surplus refrigerant, where the * speed of movement of the refrigerant becomes slow. The weight ratio of solubility of the refrigerating machine oil in the refrigerant described above changes depending on the kind of refrigerant and the refrigerating machine oil. The solubility weight proportions mentioned above are obtained through different combinations with respect to the different kinds of refrigerating machine oil listed above. 10 Figure 10 shows the solubility ratio of the alkylbenzene cooling machine oil (viscosity grade VG = 8 - 32) in the liquid refrigerant R.407C, which is a hydrofluorocarbon based refrigerant in this mode, as well as the ratio between the speed of
oil circulation and compressor frequency. As shown in Figure 10 (a), the refrigerating machine oil exhibits a solubility ratio of 1.0 to
4. 0 percent by weight with respect to the liquid refrigerant on the condensation temperature scale from + 20 ° C to +70 ° C,
but exhibits a very small solubility ratio of 0.2 to 1.8 percent by weight with respect to the liquid refrigerant on the evaporation temperature scale of -20 ° C to -15 ° C. In addition, the lower the viscosity of the refrigerating machine oil, the higher the ratio of
solubility in the liquid refrigerant. As shown in Figure 10 (b), the oil circulation velocity, i.e., a weight ratio of the refrigerating machine oil flowing with the refrigerant from the compressor to the refrigerant, generally assumes a value of about from 0.3 to 2.0 percent by weight and tends to increase with the increase of the compressor frequency. Accordingly, the refrigerating machine oil circulates in the refrigerant circuit in an amount that is shown by the oil circulation speed, and the refrigerating machine oil dissolves in the liquid refrigerant inside the receiver 54 within the scale of its solubility ratio at that temperature. However, in a case where the oil circulation rate becomes higher than the solubility ratio of the refrigerating machine oil in the liquid refrigerant under certain operating conditions, the amount of refrigerating machine oil that is circulated exceeds to an allowable amount of dissolution in the liquid refrigerant inside the receiver 54. Accordingly, the refrigerating machine oil is separated from the liquid refrigerant, and assumes the state of oil droplets or of an oil layer. Then, since the flow rate of the refrigerant is appreciably lower in the receiver than in the tube, the refrigerating machine oil stops in a large amount without being transported, and stops returning to the compressor.
In accordance with the above, it is necessary to allow the refrigerating machine oil to dissolve in the liquid refrigerant, to reliably return the refrigerating machine oil to the receiver. For example, the temperature of the liquid refrigerant inside the receiver 54 in the circuit, as shown in Figure 8, is detected by the thermistor 100, and if the temperature of the liquid refrigerant has become lower than the temperature necessary for the dissolution of the cooling machine oil, the solenoid expansion valve 32 is operated in the closing direction, or the speed of the fan 102 of the condenser 52 is lowered, which in turn causes the coolant temperature to rise liquid in the receiver 54 thereby making it possible to dissolve the refrigerating machine oil. Alternatively, in order to lower the temperature of the liquid refrigerant in the receiver 54, it is sufficient that the expansion valve 32 is operated in the opening direction, or that the number of revolutions of the fan 102 of the condenser 52 is increased, or both operations are carried out. The control of these operations is carried out by the electrical components 125 inside the external unit 121. It should be noted that, although in the previous description an example has been shown where the control is carried out by detecting the temperature of the refrigerant in the receiver, since the temperature is determined primarily with respect to the pressure in a case where the refrigerant in the receiver is in the two-phase gas-liquid state, a similar control can be performed by detecting the pressure by of a pressure sensor or similar. In the refrigeration cycle apparatus according to the present invention, by taking into account the solubility ratio of the refrigerating machine oil in the liquid refrigerant, and the relationship between the oil circulation speed and the compressor frequency, such as those shown in Figure 10 (a), the temperature and pressure of the liquid refrigerant in the receiver, and the viscosity grade of the machine oil of cooling, are set to allow the state of dissolution of the refrigerating machine oil in the liquid refrigerant to be maintained constant during operation. For example, if a VG32 viscosity grade refrigerating machine oil is used in a refrigeration cycle apparatus, where the receiver is disposed between the condenser and the pressure reducing device, as shown in Figure 10, the temperature of the liquid refrigerant in the receiver is controlled within the range of the region indicated by the arrow, when the frequency of the compressor is 120 Hz, so that the refrigerating machine oil dissolves in the liquid refrigerant. In accordance with the above, the refrigerating machine oil is reliably transported in a state of dissolving in the liquid refrigerant without stopping at the receiver. In addition, if a VG8 viscosity grade refrigerating machine oil is used in this refrigeration cycle apparatus, the solubility range of the refrigerating machine oil is expanded, as indicated by the dotted line, amplitude is produced in the aforementioned control range to return the oil, and the return of the oil becomes more reliable. Moreover, the subcooling can be controlled in correspondence with the condition of the load of the apparatus, thereby improving the efficiency and operation of the refrigeration and air conditioning apparatus. To establish subcooling at a low level, it is sufficient that the expansion valve is operated in the opening direction, or that the fan speed is lowered, or that both operations are performed. To establish subcooling at a high level, it is sufficient that an opposite operation is performed. That is, in the case of the refrigeration and air conditioning apparatus in accordance with the present invention, in the refrigerant circuit using a hydrofluorocarbon (HFC) based refrigerant as a refrigerant, and alkylbenzene or other similar oil having a weak compatibility with respect to the hydrofluorocarbon-based refrigerant as a refrigerating machine oil sealed in the compressor, and having a receiver to accumulate excess refrigerant, temperature or pressure in the receiver, and the viscosity grade of the oil refrigeration machine, are set in such a way that the solubility ratio of the refrigerating machine oil in the liquid refrigerant becomes higher than the oil circulation velocity of the refrigerating machine oil flowing out from the compressor together with the refrigerant. As a result, the refrigerating machine oil is reliably transported in the state of being dissolving in the liquid refrigerant without stopping at the receiver in a large quantity.
Eleventh Modality Referring now to Figures 11 and 12, a description of the eleventh embodiment of the present invention will be given. Figure 11 shows a configuration of a refrigerant circuit for circulating the refrigerant in the refrigerating and air-conditioning apparatus, wherein the reference numeral 1 denotes the compressor; 52, the capacitor; 54, the receiver to accumulate excess refrigerant; 55, the evaporator; 32, the opening / closing valve which is a pressure reducing device for reducing the pressure of the refrigerant on the high pressure side; 100, the thermistors for detecting the temperature, the thermistor 100 (a) being disposed in an intermediate position on the condenser, the thermistor 100 (b) being disposed between the output of the capacitor and the receiver 54, the thermistor 100 (c) being arranged on the receiver 54, and the thermistor 100 (d) is disposed between the receiver 4 and the pressure reducing device 32. The numeral 102 denotes the fan for the condenser. The numeral 103 denotes the sensors, the sensor 103 (a) being disposed between the compressor discharge tube and the condenser 52, and the sensor 103 (d) being disposed between the condenser 52 and the pressure reducing device 32. The numeral 104 denotes a heater for heating the refrigerant in the receiver 54. In addition, Figure 12 (a) shows the solubility ratio of the alkylbenzene cooling machine oil (viscosity grade 22) in the liquid refrigerant R.407C, Figure 12 (b) shows the relationship between the oil circulation speed and the compressor frequency, and Figure 12 (c) shows the relationship between the condensing temperature and the internal temperature of the receiver. As described above, to allow the refrigerating machine oil to dissolve in the liquid refrigerant in the receiver, the internal temperature of the receiver is set in such a way that the solubility ratio of the refrigerating machine oil in the 5 liquid refrigerant becomes higher than the oil circulation speed of the refrigerating machine oil. For this reason, an element is required to detect the internal temperature of the receiver and control it. -flp To detect the internal temperature of the receiver,
it is sufficient that at least one of the thermistors 100 (a) to 100 (d) and the pressure sensors 103 (a) and 103 (b) be provided. In the case where the thermistors 100 (b) to 100 (d) are provided, since the temperature of the refrigerant does not
changes from the condenser output to the pressure reducing device, it is possible to directly detect the internal temperature of the receiver. Meanwhile, in the case where the thermistor 100 (a) and the pressure sensor 103 are provided, since the temperature of the thermistor can be detected.
condensation of the refrigerant, it is possible to estimate the internal temperature of the receiver. For example, when the compressor frequency is 102 Hz as shown in Figure 12 (b) is it sufficient that the temperature of the liquid refrigerant e? the receiver is controlled within the range
indicated by the arrow. For this purpose, it is sufficient to control the condensation temperature within the scale indicated by the arrow, as shown in Figure 12 (c). In addition, to control the temperature of the liquid refrigerant in the receiver, in addition to using the aforementioned pressure reducing device and condenser fan, it is possible to adopt a method wherein the heater 104 carries out direct heating, as shown in FIG. Figure 11
Tenth Second Modality Referring now to Figures 12 and 13, a description of the twelfth embodiment of the present invention will be given. Figure 13 is another example of the refrigeration and air conditioning apparatus, which applies to an air conditioner, for example. In Figure 13, the reference numeral 1 denotes the compressor to compress a refrigerant gas; 52, the condenser for condensing the high pressure refrigerant gas discharged from the compressor 1; 31, a pre-phase pressure reducing device; 54, the receiver to accumulate excess refrigerant; 32, the posterior phase pressure reducing device; 55, the evaporator; 2, the four-way valve that has the function of reversing the flow direction of the refrigerant; 14, the refrigerating machine oil stored in the compressor 1, to effect the lubrication of the sliding portions of the compressor 1, and the sealing of the compression chamber; and 13, the excess liquid refrigerant accumulated in the receiver 54. In addition, Figure 12 (a) shows the solubility ratio of the alkylbenzene cooling machine oil (viscosity grade VG22) in the liquid refrigerant R.407C, and Figure 12 (b) shows the relationship between the oil circulation speed and the compressor frequency. The refrigerating machine oil exhibits a solubility ratio of 1.3 to 2.8 percent by weight with respect to the liquid refrigerant in the condensation temperature scale of + 20 ° C to + 70 ° C, but exhibits a very small solubility ratio from 0.2 to 1.2 percent by weight with respect to the liquid refrigerant in the evaporation temperature scale from -20 ° C to +15 ° C. In addition, the oil circulation velocity, that is, a weight ratio of the refrigerating machine oil flowing with the refrigerant from the compressor to the refrigerant, assumes a value of about 0.3 to 2.0 percent by weight, and it tends to increase with the rise of the compressor frequency. A description of the behavior of the refrigerant and the refrigerating machine oil will be given below. The high pressure refrigerant gas compressed by the compressor 1 is discharged to the condenser 52. Most of the refrigerating machine oil 14 used to lubricate the compressor and to seal the compression chamber, returns to the bottom of the sealed container, but the refrigerating machine oil, which has an oil circulation velocity of about 0.3 to 2.0 percent by weight, is discharged together with the refrigerant from the compressor 1, and enters the condenser 52. The refrigerating machine oil is It is transported by the refrigerant gas having a sufficient flow velocity, dissolved in the liquefied liquid refrigerant in the vicinity of the outlet of the condenser 52, and transported to the pre-phase pressure reducing device 31. The liquid refrigerant, whose pressure it is reduced to the so-called intermediate pressure by means of the pressure reducing device of f previous 31, enters the receiver (container liquid accumulator) 54. Here, by controlling the pressure reducing devices arranged respectively before and after the receiver 54, excess refrigerant can accumulate in correspondence with the condition of the load of the apparatus. In addition, the internal temperature of the receiver 54 is established by the control of the intermediate pressure, by means of the pressure reducing devices, in such a way that the solubility ratio of the refrigerating machine oil in the liquid refrigerant 13 inside the receiver 54 becomes higher than the oil circulation speed. For example, in a case where the compressor frequency is 120 Hz, as shown in Figure 12 (a), the temperature of the liquid refrigerant 13 in the receiver 54 is controlled within the scale of the region indicated by the arrow, as shown by the dotted line of Figure 12 (b) in such a way that the refrigerating machine oil dissolves in the liquid refrigerant 13. Accordingly, the refrigerating machine oil is reliably transported in the state of dissolving in the liquid refrigerant 13, without stopping at the receiver 54 in a large amount. The liquid refrigerant that flowed out from the receiver 54, it is further subjected to a pressure reduction, up to the "level of the necessary evaporation pressure, in such a way that the temperature declines sharply." Therefore, the solubility characteristic of the refrigerating machine oil changes to a lack of solubility or very weak with respect to the liquid refrigerant and oil refrigerating machine can not be dissolved in the liquid refrigerant is separated and forms oil droplets solubility. However, the machine oil cooling is transported through the evaporator 55, since the coolant flow rate increases abruptly due to the gasification of part of the liquid refrigerant, which occurs in the pressure reducing device of the subsequent phase 32, and since, for example, the diameter of the evaporator 55 in the next step is set to ensure a flow rate of the refrigerant gas sufficient to transport the oil e cooling machine downstream. Then, the refrigerating machine oil sucked into the compressor 1, returns to the bottom of the airtight container. Figure 13 shows an example where, instead of the expansion valves that are choke valves, capillary tubes are used as the aforementioned pre-phase and back-phase pressure reducing devices. In the case where the capillary tubes as the pressure reducing devices, the inside diameter and length of the capillary tubes used are set such that the oil cooling machine dissolves in the liquid refrigerant inside the receiver under any operating conditions. The smaller the internal diameter and the longer the capillary tubes, the greater pressure reducing effect can be obtained, in such a way that it is possible to obtain an advantage similar to that of closing the valves. Since the reduction and expansion of pressure using the capillary tubes, have self-adjusting capabilities over a certain temperature scale, the operation can be performed in a selected region and established in advance in correspondence with a previously determined refrigerant and an oil of Pre-determined cooling machine, in such a way that it becomes possible to reliably return the refrigerating machine oil to the compressor. By applying the capillary tubes thus set to the refrigerant circuit and by sealing in the machine oil predetermined refrigeration and refrigerant, a refrigerating apparatus and air conditioner, such as a refrigerator or an air conditioner is assembled , which incorporates this refrigerant circuit. The cooling apparatus and air conditioner of the present invention, such as that shown in Figure 13, is configured as follows. The compressor, the four-way valve that has the function of reversing the flow direction of the refrigerant, the condenser, the pressure reducing device of the previous phase, the receiver to accumulate the excess of refrigerant, the pressure reducing device of the Subsequent phase, and the evaporator, are connected consecutively by refrigerant tubes, and the temperature and pressure of the liquid refrigerant in the receiver are established by the pressure reducing devices arranged respectively before and after the receiver, in such a way that the proportion of The solubility of the refrigerating machine oil in the liquid refrigerant becomes higher than the oil circulation speed of the refrigerating machine oil flowing out from the compressor together with the refrigerant. In accordance with the above, the refrigerating machine oil can be transported reliably in the state of dissolving in the liquid refrigerant without stopping at the receiver in a large quantity.
Tenth Tersera Modality # Referring now to Figures 14 and 15,
will give a description of a thirteenth embodiment of the present invention. Figure 14 is an example of the refrigeration and air conditioning apparatus that is applied to an air conditioner, for example. The reference numeral
60 denotes an oil separator; 61, an oil separator network; and 62, a narrow tube to return oil. The ß refrigerant gas discharged from the compressor 1, enters the oil separator 60 from its upper part, passes through the oil separating network 61, also passes through a
outlet tube inserted in the vicinity of the center of the oil separator, and is directed towards the condenser 52. At this time, the refrigerating machine oil that is included in the refrigerant gas, adheres to the oil separating network 61 , falls, and accumulates in the bottom of the separator
oil. Separate refrigeration machine oil 81 is • returned to the compressor suction tube on the low pressure side by means of the narrow tube 62 to return oil. As shown in Figure 15, since the oil circulation speed is reduced due to the effect of the oil separator 60, the allowable range for controlling the intermediate pressure, which is effected to dissolve the refrigerating machine oil in the liquid refrigerant 13 inside the receiver 54, expands and produces amplitude. In accordance with the above, the machine oil of
The refrigeration is easily dissolved in the liquid refrigerant 13, and reliably returned to the compressor 1. In addition, the subcooling can be controlled in correspondence with the condition of the load of the apparatus, thereby improving the efficiency and operation of the refrigerant.
refrigeration cycle and air conditioning apparatus. In Figure 14, expansion valves are used
-w electrically operated as the pressure reducing devices 31 and 32. To lower the temperature of the liquid refrigerant in the receiver, it is sufficient that the valve of the
Pre-phase 31 is operated in the closing direction, and the valve of the subsequent phase 32 is operated in the opening direction, or the number of revolutions of the condenser fan is increased. If an establishment is to be provided to increase the temperature of the
liquid refrigerant, it is sufficient that the opening amount of the valve of the pre-phase 31 in the opening direction be changed, and that the opening amount, of the valve of the rear stage 32 in the closing direction, be changed, or that the number of revolutions of the fan of the condenser is decreased. If the conditions of the solubility ratio of the refrigerating machine oil in the liquid refrigerant have changed in the ratio between different kinds of
PP coolants, such as a single coolant or a mixture of
hydrofluorocarbons or hydrocarbons, such as R.410A and R.407C, and different kinds of refrigerating machine oils, such as alkylbenzene or mineral oil, if the oil circulation velocity becomes higher than the solubility ratio due to a change or similar in the
class (reciprocating, rotary, and displacement) and in the structure of the compressor, an adjustment is first made by changing the method to control the expansion valves and the condenser fan. However, if the oil circulation speed becomes higher than the ratio of
The solubility of the refrigerating machine oil in the liquid refrigerant, even after the adoption of a heater, is sufficient to provide an oil separator having a characteristic required for recovery, during the assembly of the refrigerant circuit.
refrigerant. Depending on the kinds of refrigerant and 'cooling machine oil, however, an oil recovery element is selected in advance with respect to the oil circulation speed, and an adjustment of the expansion valves and the like is made, as required. In order not to increase the kinds of oil separators, if the declination in the oil circulation speed does not reach a necessary scale, a plurality of oil separators can be configured in series. oil. 10 The process described above to determine the specifications can also be determined in advance, conducting calculations and examinations through the following procedure. First, the refrigerant classes are selected
and refrigeration machine oil in light of the specifications, operating conditions, circuit conditions, and the like, which are established in advance. Next, the coolant temperature and the coolant pressure in the coolant are calculated.
Under the respective conditions, an examination is made as to whether the solubility ratio of the refrigerating machine oil in the liquid refrigerant is greater or less than an estimated oil circulation velocity, and the specifications on the number of separators
of oils required, the presence or absence of a heater, and the like. These establishments can be determined through a program where data is entered in advance. In the selection of the oil, there are several elements that must be taken into consideration, including the solubility in the refrigerant, the operation of lubrication, the electrical insulation, and the property against the sludge, the stability against water, hydrogen, temperature , and life, fluidity at low temperature, the effect on the environment, and the cost. By making an adjustment in the control, and by adding an oil separator in the assembly procedure as described above, the selection range of the refrigerating machine oil is expanded, so that the use of oil becomes possible of cooling machine that is excellent in the above mentioned operations. In addition, in the event that a change in the refrigerant class has occurred with respect to the apparatus being used for the reasons of an environmental or similar measure, including when the compatibility between a newly introduced refrigerant and the refrigerant is lost. The refrigerating machine oil, or a problem in oil return, it becomes possible to treat this problem by changing the control without replacing the oil. In addition, in a case where a change is made in the course of time in the refrigerant class in the refrigerant circuit where the compressor, the condenser, the pressure reducing devices, the evaporator, and the liquid storage element able to accumulate the refrigerant, are connected by tubes, the speed at which the refrigerating machine oil dissolves in the refrigerant also changes. In addition, for example, if the concentration of the refrigerant becomes high, the amount of oil flowing out of the compressor to the circuit also increases. That is, since the oil circulation speed becomes large, the refrigerating machine oil stops returning to the compressor, and a problem arises, and it is sufficient that the details of the control are changed by changing the establishments of the temperature and pressure of the refrigerant in the liquid storage element as e? the present invention, in such a way that the refrigerating machine oil is dissolved in the liquid refrigerant inside the liquid storage element. Incidentally, at the time of this change of the refrigerant class, the solubility ratio can be easily known from the past data. Meanwhile, if an experiment is conducted using a model machine based on the new combinations of the refrigerant and the refrigerating machine oil, it is easily possible to estimate the degree to which the oil will flow in a large quantity. Alternatively, the control can be determined by performing the operation, and confirmation that the amount of oil flowing out of the circuit is large, by checking the amount of oil in the compressor, and making a determination. This problem differs from the case of a new installation, in which case, the specifications can be studied with sufficient anticipation, and there are cases
wherein a single refrigerant should be changed to a plurality of refrigerant classes. This problem also arises due to the relationship between the refrigerant and the refrigerating machine oil, which has a solubility ratio such that it will exceed the numerical levels of
weak compatibility described above. Since the present invention can deal with any case by providing control without replacing the oil, it is possible to treat it with an environmental and similar measure, in a simple and flexible manner. Although the oil separator is disposed in the vicinity of the discharge outlet of the compressor, the oil separator may be disposed inside the compressor, depending on the structure of the compressor. In this refrigeration and conditioning apparatus
of air, since the efflux of the refrigerating machine oil inside the compressor to the condenser, the receiver, and the evaporator is suppressed, expands the permissible range of control that is effected to allow the refrigerating machine oil to Dissolve in the liquid refrigerant inside the receiver, so that the refrigerating machine oil in the receiver is reliably returned to the compressor. In addition, since the refrigerating machine oil that attaches to the walls of the condenser tube and to the evaporator may decrease, the heat exchange efficiency does not decline.
Fourteenth Modality Referring now to Figure 16, a description of the fourteenth embodiment of the present invention will be given. Figure 16 is an example of the refrigeration and air conditioning apparatus that is applied in an air conditioner, for example. The reference numeral 31 denotes the pressure reducing device of the previous phase comprising an orifice. In a case where a large amount of refrigerating machine oil is temporarily discharged from the compressor 1, such as during the restart after it "sleeps" the refrigerant, the liquid refrigerant and a large amount of refrigerating machine oil that can not dissolve in the liquid refrigerant, they flow in the vicinity of the outlet of the condenser 2.
However, when it passes through the orifice section of the pressure reducing device of the pre-phase 31, the refrigerating machine oil which is not soluble in the tube, assumes a state of fine mist, and flows inwardly from the receiver 54. For this reason, even when using a refrigerating machine oil whose specific gravity is smaller than that of the refrigerant, the refrigerating machine oil does not immediately form a separate layer P inside the receiver 54, but assumes a state where
suspends in the liquid refrigerant, and the refrigerating machine oil also flows out with the flow of the liquid refrigerant. Accordingly, the large amount of cooling machine oil flowing to the receiver 54, is quickly returned to the compressor without stopping here.
It should be noted that, in order to make the oil droplets finer, it is sufficient that the droplets of oil are passed quickly through a narrow portion, and instead a structural component, such as like a mud filter. Eighteenth Modality Referring now to Figures 16, 17, and 18, a description of the fifteenth embodiment of the present invention will be given. Figures 17 and 18 show examples of the structure or whose receiver 54 is shown in Figure 16, and is used in the present invention. The reference numeral 41 denotes a coolant inlet pipe for the coolant to flow into the receiver 54; 42, a tube of
refrigerant outlet; and 43, an opening for communication between each tube with the receiver. In a case where a large amount of refrigerating machine oil is temporarily discharged from the compressor 1, such as during the restart after it "sleeps" the
refrigerant, the liquid refrigerant a large amount of refrigerating machine oil that can not be dissolved in the liquid refrigerant, flow, pass through the pressure reducing device of the pre-phase 31, and flow into the receiver 54. Without However, since the tube
inlet 41 and outlet tube 42 are configured in such a way as to oppose each other as shown in Figure 17, most of the refrigerating machine oil flows out without being stopped in receiver 54, and returns quickly to the compressor. In addition, in the Example shown
in Figure 18, since the inlet and outlet of the liquid refrigerant between the tube and the receiver 54 are effected through the communication hole 43, the refrigerating machine oil flows through the tube without entering the receiver 54, and return quickly to the compressor. In a
In the case where the refrigerating machine oil is used, the specific weight of which is greater than that of the liquid refrigerant, it is sufficient that the communication hole 43 is provided in such a way that it is oriented laterally or upward, while in a case where the
If the refrigerating machine oil whose specific weight is smaller than that of the liquid refrigerant, it is sufficient that the communication hole 43 is provided in such a way that it is oriented laterally or downwardly. jV The refrigeration and conditioning apparatus of
The air in accordance with the present invention is structured in such a way that the opening of the inlet pipe and the opening of the outlet pipe are opposite each other at the bottom of the receiver, and the influence of the oil of the winding machine is suppressed. refrigeration that is not soluble in the refrigerant
liquid, towards the receiver. In accordance with the above, even when a large amount of refrigerating machine oil is temporarily discharged to the receiver, most of the refrigerating machine oil flows out without being stopped at the receiver.
receiver, and quickly returns to the compressor, by virtue of the configuration where the inlet tube and the outlet tube are opposite one another.
Sixteenth Modality 25 Referring now to Figures 16 and 19, a description of a sixteenth embodiment of the present invention will be given. The structure provided is such that the discharge pipe of the compressor 1 is provided with a portion of reduced diameter pipe 63 outside the sealed container 5, and a system is adopted wherein the tongs 111 of a rig 113 to close the discharge pipe in a tightness test in the manufacturing process of the compressor, they are trapped in the portion of reduced diameter pipe 13, to ^ F to press the tongs 111 by means of the springs 112. In a
where a high-pressure refrigerant, such as R.410A, is used as a hydrofluorocarbon-based refrigerant, although the tightness test is performed conventionally under the pressure 28 kgf / cm G in the compressor using R.22, it has been It is necessary to perform the tightness test under a
considerably high pressure of 45 kgf / cprG when using R.410A. Under the configuration adopted in
> In this modality, it is difficult for the rig to come off, even when a high pressure is applied, in such a way that the airtightness test can be carried out in a safe way
and reliable. Conventionally, when the interior of the compressor is set at a high pressure, the rig closing the discharge tube tends to come off due to the pressure difference, and the conventionally used rigging is configured
in such a way that the tongs are pressed against the discharge tube, and the rigging is fixed by the friction force. On the other hand, in the present invention, indented portions are provided on the compressor discharge tube, as shown in Figure 16. If
provides the portion of reduced diameter tube (neck)
63 on the discharge tube, the tongs of the rigging can be caught in it, and it can be made more difficult to get out than in the conventional configuration. Therefore, the air tightness test of the
compressor can be performed in a safe and reliable way. In the above description of the modes, the reer 54 is arranged in an intermediate pressure portion, but the reer 54 can be arranged in any position, as long as the oil can be recovered. In the analysis
final, if the pressure and temperature of the liquid refrigerant in the reer are set in such a way that the solubility ratio of the refrigerating machine oil in the liquid refrigerant becomes higher than the oil circulation velocity of the refrigeration machine
flowing out of the compressor to the refrigerant circuit during operation, even when a large amount of oil temporarily flows out, the oil can be returned reliably. In an incidental manner, even when the muffler is provided
suction 101 on the suction side of the compressor, as shown in Figure 11, and an unsupported oil is adopted, the internal oil can be reliably recovered by a conventionally known recovery structure. That is, in the present invention, if the oil is preferably allowed to flow after dissolving in the refrigerant on the upstream side of the circuit, it is possible to obtain a highly reliable apparatus in which the oil clots flow, for example, towards the internal and similar unit of the air conditioner, and a clogging in the capillary tubes and the like is prevented. In addition, although a large size air-conditioning and refrigerating apparatus is used as an object for the liquid storage portion, in the case of a small-scale circuit, such as in a refrigerator, the liquid storage portion can be Use naturally for a portion where the liquid refrigerant is stopped, such as a dryer or a filter device that is connected to the tube. By virtue of the configurations of the modalities described above, since, for example, the range can be expanded to control the subcooling that is carried out in correspondence with the load condition of the apparatus according to the present invention, the efficiency and operation of refrigeration and air conditioning equipment.
In addition, since the excess refrigerant can be stopped in correspondence with the condition of the load of the apparatus, and a large amount of liquid refrigerant is not returned to the compressor, the reliability of the refrigerant is improved.
compressor. Moreover, the apparatus according to the present invention is capable of dealing with the inversion of the refrigeration cycle, such as by changing the four-way valve, has a simple structure, is excellent in the
| operating at cost, and does not cause a decline in
operation due to dust clogging.
Advantages of the Invention As described above, in the refrigerant circulation apparatus in accordance with the first
aspect of the invention, since the liquid storage vessel to allow the oil droplets to flow out in a suspended form, is connected between the condenser and the pressure reducing device, the cooling machine oil flowing outwardly of the compressor
can be returned reliably to the compressor, and proper lubrication and sealing functions can be maintained for the compression elements. Therefore, it is possible to obtain an apparatus where the reliability of the compressor is high. In addition, the structure is simple, the
productivity and performance for cost are outstanding, and there is no decline in performance due to dust clogging. In refrigerant circulation apparatus according to the second aspect of the invention, since the structure provided is such that the refrigerant accumulates on the flow side, where the excess refrigerant is present, and the liquid storage container allows that the oil droplets flow outward in a suspended form. Accordingly, the refrigerating machine oil flowing out of the compressor can be returned reliably to the compressor, and the proper lubrication and sealing functions for the compression elements can be maintained. Therefore, it is possible to obtain an apparatus where the reliability of the compressor is high. In addition, in a case where the flow direction of the refrigerant is reversed, since the refrigerant does not accumulate in the container, nor does the refrigerating machine oil accumulate, the refrigerating machine oil can be returned to the refrigerant machine. compressor. In the refrigerant circulation apparatus according to the third aspect of the invention, since the liquid storage vessel is interposed between the pair of pressure reducing devices, the refrigerant can accumulate regardless of the flow direction of the refrigerant, and since the container is arranged in a high pressure liquid section, the refrigerating machine oil dissolves in the refrigerant, and can be returned to the compressor without stopping in the liquid storage vessel. In the refrigerant circulation apparatus according to the fourth aspect of the invention, since the refrigerant from the inlet in a lower portion of the liquid storage vessel, flows towards the lower surface of the oil layer, and the oil layer is stirred by the flow of the refrigerant, the dissolution of the refining machine oil in the refrigerant is provided. In addition, since the oil flows out from the outlet in the lower portion, the oil can be returned to the compressor in a simple configuration, and the compressor's reliability can be improved. In the refrigerant circulation apparatus according to the fifth aspect of the invention, since the refrigerant in the container is stirred upon imparting a change to the state of the refrigerant flowing * in from the container inlet, the mixture of the interface between the refrigerant and the refrigerating machine oil, thus promoting the dissolution of the refrigerating machine oil in the refrigerant. Consequently, the return of the cooling machine oil stopped in the container to the compressor is promoted, and the reliability of the compressor can be improved.
In the refrigerant circulation apparatus according to the sixth aspect of the invention, since the liquid storage container is interposed between the pair of pressure reducing devices, the refrigerant can accumulate regardless of the flow direction of the refrigerant, and since the container is arranged in a high pressure liquid section, the refrigerating machine oil dissolves in the refrigerant, and can be returned to the compressor without stopping in the liquid storage vessel. Since the pressure reducing device on the low pressure side is controlled, it is possible to obtain the required superheat, and the degree of superheating in the suction of the compressor can be controlled, thereby making it possible to obtain an apparatus having excellent efficiency. operative In addition, since the amount of refrigerant accumulated in the container, and the refrigerant temperature, are controlled, the dissolution of the refrigerating machine oil in the refrigerant can be promoted. Since the pressure reducing device on the high pressure side is controlled, it is possible to obtain the required subcooling, thereby making it possible to obtain an apparatus having excellent operating efficiency. In addition, since the amount of refrigerant accumulated in the container and the temperature of the refrigerant are controlled, the dissolution of the refrigerating machine oil in the refrigerant can be promoted. In addition, since the pressure reducing devices on the low pressure side and on the high pressure side are controlled in an interlocking manner, the degree of superheating and the degree of subcooling can be controlled simultaneously at appropriate values. Accordingly, the apparatus can fully demonstrate its capabilities, and an apparatus having excellent operating efficiency can be obtained. In the refrigerant circulation apparatus according to the seventh aspect of the invention, since the pressure reducing devices are controlled, in such a way that the liquid refrigerant in the container becomes temporarily emptied, even when a large amount of liquid is stopped. refrigerating machine oil in the container, the refrigerating machine oil is allowed to flow out of the container in a reliable manner, thereby making it possible to reliably return the refrigerating machine oil. In refrigerant circulation apparatus according to the eighth aspect of the invention, since a controllable control valve is used, such as the pressure reducing device, and the control valve is controlled over a period of time previously determined after start-up, the refrigerant which temporarily stops after starting can be discharged, and it is possible to deal with a malfunction, such as "sleeping" the refrigerant. In the refrigerant circulation apparatus according to the ninth aspect of the invention, since the refrigerating machine oil can reliably be returned to the compressor without stopping a large quantity of refrigerating machine oil in the liquid storage vessel, they can maintain the proper functions of lubrication and sealing for compressor compression elements, and a highly reliable product can be obtained. In the refrigerant circulation apparatus according to the tenth aspect of the invention, it is possible to obtain an efficient apparatus that does not cause a decline in the efficiency of the heat exchanger, and that can expand the range of control, thus making it possible get an efficient device. In the refrigerant circulation apparatus according to the eleventh aspect of the invention, since the oil is made to dissolve, making the oil droplets finer, the oil can be reliably recovered. In the refrigerant circulation apparatus according to the twelfth aspect of the invention, since the efflux of the refrigerating machine oil used in the lubrication and sealing of the compressor to the condenser, to the liquid storage tank, and to the evaporator is eliminated, the cooling machine oil flowing outwards can be reliably returned to the compressor, and the heat exchange efficiency of the condenser and the evaporator is prevented from declining. In the refrigerant circulation apparatus according to the thirteenth aspect of the invention, even in a case where a large amount of refrigerating machine oil is temporarily discharged from the compressor, the refrigerating machine oil can be returned reliably to the compressor without stopping at the receiver. In the refrigerant circulation apparatus according to the fourteenth aspect of the invention, in the manufacture of the compressor, a tightness test can be performed with safety and reliability. In the refrigerant circulation apparatus according to the fifteenth aspect of the invention, including when using a refrigerating machine oil having no solubility or having a weak solubility in the refrigerant under previously determined conditions, the machine oil # Refrigeration can be returned reliably, in such a way that it is possible to obtain an appliance where the compressor is highly reliable, and for which maintenance is facilitated. In the method of assembling a refrigerant circuit according to the sixteenth aspect of the invention, since the temperature or the pressure of the refrigerant in the liquid accumulator element is set in such a
# way that the solubility ratio of the machine oil
cooling in the liquid refrigerant inside the liquid storage element becomes approximately equivalent to, or higher than, the oil circulation speed of the cooling machine oil flowing out from the compressor to the refrigerant circuit.
during operation, it is possible to simply assemble the refrigerant circuit, which facilitates oil recovery. In the refrigerant circulation apparatus according to the seventeenth aspect of the invention,
as a measure against Freon that destroys the ozone layer in air conditioners, in refrigerators, and the like, it is possible to provide a measurement by performing the operation of replacing only the refrigerant, and by changing only the
setting the controller without changing the refrigerating machine oil. Accordingly, since processing can simply be provided, it is possible to provide an effective measure for the protection of the environment.
Brief Description of the Drawings Figure 1 is a conceptual diagram of a refrigerant circulation apparatus illustrating a first embodiment of the present invention. Figure 2 is a conceptual diagram of a liquid accumulator container illustrating the first and second embodiments of the present invention. Figure 3 is a conceptual diagram of the refrigerant circulation apparatus, illustrating another embodiment of the present invention. Figure 4 is a conceptual diagram of the refrigerant circulation apparatus illustrating yet another embodiment of the present invention. Figure 5 is a conceptual diagram of the refrigerant circulation apparatus, illustrating a further embodiment of the present invention. Figure 6 is a diagram illustrating a change in the stopped state of the oil in a liquid storage vessel, after starting, in accordance with the present invention.
Figure 7 is a conceptual diagram of the refrigerant circulation apparatus, illustrating a still further embodiment of the present invention. Figure 8 is a schematic diagram of an air conditioner and cooling apparatus, illustrating a further embodiment of the present invention. Figure 9 is a schematic diagram of the refrigeration and air conditioning apparatus, illustrating the additional embodiment of the present invention. Figure 10 is a diagram illustrating the solubility ratio of a refrigerating machine oil in a liquid refrigerant, and the relationship between the oil circulation velocity and the frequency of the compressor according to the present invention. Figure 11 is a schematic diagram of the refrigeration and air conditioning apparatus, illustrating a further embodiment of the present invention. Figure 12 is a diagram illustrating the solubility ratio of the refrigerating machine oil in the liquid refrigerant, the ratio between the oil circulation speed and the compressor frequency, and the relationship between the condensing temperature and the internal temperature of a receiver in accordance with a further embodiment of the present invention. Figure 13 is a schematic diagram of the cooling and air conditioning apparatus *, illustrating the additional embodiment of the present invention. Figure 14 is a schematic diagram of the refrigeration and air conditioning apparatus, illustrating a further embodiment of the present invention. Figure 15 is a diagram illustrating the solubility ratio of the refrigerating machine oil in the liquid refrigerant, and the ratio between the oil circulation velocity and the compressor frequency, in accordance with the additional embodiment of the present invention. . Figure 16 is a schematic diagram of the refrigeration and air conditioning apparatus, which illustrates a further embodiment of the present invention. Figure 17 is a diagram illustrating the structure of the receiver in accordance with the additional embodiment of the present invention. Figure 18 is a diagram illustrating the structure of the receiver in accordance with the additional embodiment 20 of the present invention. Figure 19 is a partial explanation diagram of the apparatus in accordance with a further embodiment of the present invention. Figure 20 is a schematic diagram of a conventional refrigeration and air conditioning cycle apparatus. Figure 21 is a schematic diagram of another conventional example of the refrigeration and air conditioning cycle apparatus. 5 Explanation of Reference Numerals 1: compressor, 2: four-way valve, 3: internal heat exchanger, 4: external heat exchanger, 5: pressure reducing device, 5a: device
* 10 pressure reducer in the previous phase, 5b: pressure reducing device in the rear phase, 6: liquid storage tank, 7: liquid storage tank, 8: inlet pipe for the liquid storage tank, 9: pipe outlet for the liquid storage tank, 10:
liquid storage tank, 11: inlet pipe for the liquid storage tank, 12: outlet pipe for the liquid storage tank, 13: coolant, 14: cooling machine oil, 15a: electrically operated expansion valve of the side of the previous phase, 15b:
electrically operated expansion valve on the side of the rear phase, 16: internal fan, 17: external fan, 52: condenser, 54: receiver, 55: evaporator, 7: accumulator, 14: refrigerating machine oil, 13: refrigerant , 60: separated from oil, 61: separation network from
oil, 62: narrow tube to return oil, 63: portion of pP reduced diameter tube of a compressor discharge tube, 31: pressure reducing device of the previous phase, 32: pressure reducing device of the subsequent phase, 41: Receiver inlet tube, 42: 5 receiver outlet tube, 43: Receiver communication hole, 71: Accumulator outlet tube, 72: Oil return hole in accumulator outlet tube, 81: cooling machine oil, 100: thermistor, 101: jKr * mofle, 102: fan for condenser, 103: sensor
pressure, 104: heater, 110: O ring for sealing, 111: clamp, 112: spring, 113: rigging, 121: external unit, 122: internal unit, 123: ventilation damper, 124: extension tube, 125: electrical component for the external unit, and 126: electrical component for the internal unit. fifteen
Claims (17)
1. A refrigerant circulation apparatus having a refrigerant circuit, wherein a compressor, a condenser, a pressure reducing device, and an evaporator are consecutively connected, by means of refrigerant tubes, said refrigerant circulation apparatus comprising: liquid storage vessel connected between the condenser and the pressure reducing device, to allow the oil droplets to flow out in a suspended form, by using a refrigerating machine oil that does not exhibit solubility or exhibits 15 a very weak solubility in terms of a solubility weight ratio of the refrigerating machine oil in a. liquid refrigerant under conditions of condensation pressure and condensation temperature, and that does not exhibit solubility or exhibits a very weak solubility in terms of 20 a solubility by weight ratio of the refrigerating machine oil in the liquid refrigerant under conditions of evaporating pressure and evaporating temperature, and having a specific gravity smaller than the refrigerant.
A refrigerant circulation apparatus according to claim 1, further comprising: ^ an element for changing the flow direction of the refrigerant, the liquid accumulator container connecting to allow the oil droplets to flow outwardly in a suspended form, between the condenser and the pressure reducing device, on a flow side where the refrigerant is exceeded.
3. A refrigerant circulation apparatus having a refrigerant circuit, wherein a compressor, an element for changing a flow direction of the refrigerant, a condenser, a pair of pressure reducing devices, and an evaporator are consecutively connected JB. , by means of refrigerant tubes, this refrigerant circulation device comprising: a liquid storage tank interposed 15 between the pressure reducing devices, by using a refrigerating machine oil which does not exhibit solubility or exhibits a very weak solubility in terms of a weight ratio of the solubility of the refrigerating machine oil in a liquid refrigerant, 20 under the conditions of condensation pressure and condensation temperature, and that does not exhibit solubility or exhibits a very weak solubility in terms of a weight ratio of the solubility of the refrigerating machine oil in the liquid refrigerant, under the conditions of pressure from 25 evaporation and evaporation temperature.
4. A refrigerant circulation apparatus according to claim 3, wherein refrigerant pipes are inserted into an inlet and outlet of the refrigerant, into and from the liquid storage tank, into the container, from a lower portion thereof. , and the refrigerant that is inside the liquid storage container is allowed to flow from bottom to top, and to agitate.
A refrigerant circulation apparatus according to claim 3 or 4, wherein the refrigerant that is inside the liquid storage vessel is agitated by changing a phase state of the refrigerant, or a state of pressure thereof, in a position wherein the refrigerant flows inwardly from an inlet tube of the liquid storage vessel, to accumulate excess refrigerant.
6. A refrigerant circulation apparatus according to claim 3, 4, or 5, which further comprises: at least one subcooling detector element, for detecting a characteristic subcooling value corresponding to a degree of subcooling of the refrigerant, in an output of the condenser, and a superheat detector element, to detect a characteristic superheat value corresponding to a degree of superheating of the refrigerant sucked into the compressor; a calculating element for calculating a deviation with a target value corresponding to at least one of a result of the detection by the superheating detector element, and a result of the detection by the subcooling detector element; and a controlling element, for controlling a control valve of at least one of the pressure reducing devices on one side of high pressure and one side of low pressure, based on the result of the calculation by means of the calculating element.
7. A refrigerant circulation apparatus according to claim 3, 4, 5, or 6, wherein a controllable control valve, such as the pressure reducing device, and an area of an opening in the valve are used. of control that controls, in such a way that the liquid refrigerant in the container becomes temporarily empty.
8. A refrigerant circulation apparatus according to claim 7, wherein the controllable control valve, such as the pressure reducing device, is used and the control valve is controlled with the course of a predetermined time. after the start
9. A refrigerant circulation apparatus, comprising: i a refrigerant circuit, wherein a compressor, a condenser, a pair of pressure reducing devices, and an evaporator are consecutively connected, by means of refrigerant pipes; a liquid storage vessel provided in the refrigerant circuit, for accumulating a refrigerant, and a refrigerating machine oil that does not exhibit solubility or exhibits a very weak solubility in a liquid refrigerant under conditions of condensation pressure and condensation temperature, and under conditions of evaporation pressure and evaporation temperature with respect to the refrigerant circulating in the refrigerant circuit; and an element that establishes the oil solubility ratio to establish at least one of the temperature and pressure of the refrigerant in the liquid storage vessel, such that a solubility ratio of the refrigerating machine oil in the liquid refrigerant .It is inside the liquid storage container, becomes approximately equivalent to, or higher than, a rate of oil circulation from the cooling machine oil flowing out from the compressor to the # refrigerant circuit during operation.
10. A refrigerant circulation apparatus according to claim 9, wherein pressure reducing devices are disposed respectively before and after 5 after the liquid storage tank arranged in the refrigerant circuit, to accumulate the refrigerant, and the temperature and pressure of the refrigerant in the liquid storage tank are established by the devices Jp pressure reducers, in such a way that the proportion of The solubility of the refrigerating machine oil in the liquid refrigerant that is inside the liquid storage vessel, becomes approximately equivalent to, or higher than, the flow rate of the refrigerating machine oil flowing outwardly. 15 from the compressor to the refrigerant circuit during operation.
11. A refrigerant circulation apparatus according to claim 9, wherein an element is used to make thinner oil droplets, as when 20 less a pre-phase pressure reducing device of the pressure reducing devices arranged respectively before and after the liquid storage container.
12. A refrigerant circulation apparatus, comprising: a refrigerant circuit in which a compressor, a condenser, a pressure reducing device, and an evaporator are consecutively connected, by means of refrigerant pipes; a liquid storage vessel provided in the refrigerant circuit, for accumulating a refrigerant and a refrigerating machine oil, which does not exhibit solubility, or which exhibits a very weak solubility in a liquid refrigerant, under conditions of condensation pressure and temperature. condensation, and under conditions of evaporation pressure and evaporation temperature with respect to the refrigerant circulating in the refrigerant circuit; and an oil recovery element disposed in an interior of the compressor, or on a discharge side of the compressor, to lower an oil circulation rate, such that the oil circulation rate of the cooling machine oil flowing outwardly from the compressor to the refrigerant circuit during operation becomes approximately equivalent to, or lower than, a ratio in which the liquid refrigerant that is inside the liquid storage vessel dissolves the refrigerating machine oil.
13. A refrigerant circulation apparatus according to claim 4, 5, 9, 10, 11, or 12, wherein an inlet tube is configured to flow the refrigerant into the liquid storage vessel from the circulation circuit. refrigerant, and an outlet tube for the refrigerant to flow from the liquid storage vessel into the refrigerant circuit, with its respective tube openings disposed in a lower portion of the liquid storage container, and configured to allow the refrigerant to flow directly from the inlet tube to the outlet tube.
14. A refrigerant circulation apparatus according to claim 3, 4, 5, 9, or 12, which further comprises a coupling portion disposed on a «Tube on the discharge side of the compressor, and having a changed external tube diameter.
15. A refrigerant circulation apparatus according to claim 1, 3, 4, 5, 9, or 12, wherein the refrigerating machine oil has no solubility or has a very weak solubility with respect to the refrigerant, being its weight ratio of solubility in the liquid refrigerant under the conditions of condensation pressure and condensation temperature of 0.5 to 7 weight percent, and its ratio by weight of solubility in the liquid refrigerant under the conditions of evaporation pressure and evaporation temperature from 0 to 2.0 percent by weight.
16. A method for assembling a refrigerant circuit, which comprises the steps of: providing, in the refrigerant circuit, a liquid accumulating element for accumulating a refrigerant circulating in a refrigerant circuit, where a compressor, a compressor, is connected consecutively. condenser, a pressure reducing device, and an evaporator, by means of refrigerant tubes; sealing, in the refrigerant circuit, a refrigerating machine oil which does not exhibit solubility or which exhibits a very weak solubility in a liquid refrigerant under conditions of condensation pressure and condensation temperature, and under conditions of evaporation pressure and temperature of evaporation; and setting at least one of the temperature and pressure of the refrigerant in the liquid storage element, such that a solubility ratio of the refrigerating machine oil in the liquid refrigerant inside the liquid storage element, becomes approximately equivalent a, or higher than, a rate of oil circulation from the cooling machine oil flowing out from the compressor to the refrigerant circuit during operation.
17. A method for assembling a refrigerant circuit, which comprises the steps of: changing a refrigerant class to be circulated in a refrigerant circuit, where a compressor, a condenser, a pressure reducing device are consecutively connected , an evaporator, and a liquid storage element for accumulating a refrigerant, by means of refrigerant pipes, from a sealed refrigerant to another refrigerant; continue to seal the refrigeration machine oil sealed in the compressor, even when changing the refrigerant class; and setting at least one of the temperature and pressure of the refrigerant in the liquid storage element, such that a solubility ratio of the refrigerating machine oil in the changed refrigerant becomes approximately equivalent to, or higher than, that of the refrigerant. , a rate of oil circulation from the refrigerating machine oil flowing out from the compressor to the refrigerant circuit during operation, in a case where the solubility ratio of the refrigerating machine oil is lower than the proportion of oil circulation.
Applications Claiming Priority (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| HEHEI.9-000168 | 1997-01-06 | ||
| JP9-000168 | 1997-01-06 | ||
| JP9-007837 | 1997-01-20 | ||
| HEHEI.9-007837 | 1997-01-20 | ||
| JP9-308449 | 1997-11-11 | ||
| HEHEI.9-308449 | 1997-11-11 | ||
| JP9-308448 | 1997-11-11 | ||
| HEHEI.9-308448 | 1997-11-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| MXPA98000237A true MXPA98000237A (en) | 1999-02-24 |
Family
ID=
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