CN201885488U - Screw type cooling system and control method thereof - Google Patents
Screw type cooling system and control method thereof Download PDFInfo
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- CN201885488U CN201885488U CN2010206181525U CN201020618152U CN201885488U CN 201885488 U CN201885488 U CN 201885488U CN 2010206181525 U CN2010206181525 U CN 2010206181525U CN 201020618152 U CN201020618152 U CN 201020618152U CN 201885488 U CN201885488 U CN 201885488U
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Abstract
The utility model relates to a screw type cooling system, which comprises a screw type compressor, a condenser, an evaporator, an electronic expansion valve, an oil separator, a first electromagnetic valve, a second electromagnetic valve and an ejector, the outlet of the screw type compressor is connected with the inlet of the oil separator through a first pipeline, the coolant outlet of the oil separator is connected with the inlet of the condenser through a second pipeline, the outlet of the condenser is connected with the inlet of the evaporator through a third pipeline, the outlet of the evaporator is connected with the inlet of the screw type compressor through a fourth pipeline, and the electronic expansion valve is arranged in the third pipeline. The screw type cooling system is characterized in that: the ejector is arranged on the fourth pipeline, the high-pressure port of the ejector is connected with the return oil inlet of the oil separator through a fifth pipeline, the low-pressure port of the ejector is connected with the return oil inlet of the evaporator through a sixth pipeline, and the first electromagnetic valve and the second electromagnetic valve are respectively arranged in the fifth pipeline and the sixth pipeline.
Description
Technical field
The utility model relates to a kind of screw type cold system and control method thereof.
Background technology
The screw type cold system is because it is simple in structure, and efficient is high and be widely used in the air-conditioning system.It is with helical-lobe compressor as power source, the container that utilizes evaporimeter and condenser to carry out heat exchange as cold-producing medium and water or air, the refrigeration by cold-producing medium or heat circulation makes indoor acquisition comfort temperature.
In the screw type cold system, generally use flooded evaporator.This flooded evaporator 800 is made of shell 13 and heat exchanger tube 11 as shown in Figure 2, cold-producing medium 12 is in the outside of heat exchanger tube 11, water flows in heat exchanger tube 11, and its heat transfer temperature difference is little, and evaporating temperature cold-producing medium 12 more shown in Figure 1 is high a lot of at the dry evaporator 80 of heat exchanger tube 11 flows inside.But simultaneously, dry evaporator 80 flows in heat exchanger tube 11 because of cold-producing medium 12, discharge the compressor oil of compressor inside with cold-producing medium 12, can get back to compressor inside very soon, and flooded evaporator 800, because of cold-producing medium 12 in heat exchanger tube 11 outsides, flowing velocity is slower, must have independent oil return apparatus to make compressor oil can be back to helical-lobe compressor.
Compressor oil is vital for the screw rod machine, it plays lubricated and sealing function on the one hand, the increment of load of helical-lobe compressor and off-load also be unable to do without compressor oil on the other hand, simultaneously, if a large amount of compressor oils enters evaporimeter and condenser, will form oil film on the heat exchanger tube surface, influence heat exchanger effectiveness, and compressor air-discharging will inevitably be taken compressor oil out of, therefore must make when moving compressor oil as much as possible be back in the helical-lobe compressor with the assurance system can stablize, efficiently operation.
Present most full-liquid type screw rod machine product in running, by jet pump or the oil return of oil pump continuous uninterrupted, comes the assurance system can stable operation.
Fig. 3 is the system diagram of a kind of full-liquid type screw rod air conditioner unit (prior art 1).In prior art 1, the oil-out of oil eliminator 3 links to each other with the inlet of helical-lobe compressor 1 by the 1st filter 9a, on the inlet of helical-lobe compressor 1 and the pipeline between the flooded evaporator 8, injector 6 is installed, the refrigerant outlet of oil eliminator 3 is connected on the interface of injector 6 by magnetic valve 7b, and the oil return pipe of flooded evaporator 8 is connected on another interface of injector 6 by the 3rd filter 9c.Compressor oil in the helical-lobe compressor 1 is separated at oil eliminator 3 with compressed cold-producing medium.High-pressure refrigerant after the separation is after condenser 2 condensations, and evaporation in flooded evaporator 8 becomes to be compressed after entering helical-lobe compressor 1 behind the gas refrigerant again.And the compressor oil after separating is through the 1st filter 9a, and magnetic valve 7a turns back in the helical-lobe compressor.When opening magnetic valve 7b, the compressor oil in the higher pressure refrigerant gas injection flooded evaporator 8 (during shutdown, the magnetic valve action makes valve closing) is got back in the helical-lobe compressor 1 it.
This oil return way is used by most of screw rod machine manufacturer at present.But this method is used the compressor oil in the higher pressure refrigerant gas ejection system, certainly will reduce the cold-producing medium that participates in kind of refrigeration cycle, thereby reduces refrigeration, heating capacity.Simultaneously, oil return continuously action makes the cold-producing medium that still has neither part nor lot in heat exchange in the evaporimeter 8 also get back to helical-lobe compressor 1 through oil return system.Show that by a large amount of experiments more than loss can account for about 5% of unit refrigerating capacity, thereby has influence on the efficient of screw rod unit.
Fig. 4 is the schematic diagram of another kind of full-liquid type screw rod machine cooling system (prior art 2).In prior art 2, as shown in the figure, the outlet of helical-lobe compressor 1 is connected with the import of oil eliminator 3, the outlet of oil eliminator 3 is connected with the import of condenser 2, the oil return line of described oil eliminator 3 is divided into two-way, the magnetic valve 7 of leading up to is connected with the import of helical-lobe compressor 1, and another road is connected with the import of helical-lobe compressor 1 by injector 6, and the oil return opening of evaporimeter 8 is connected with injector 6 by magnetic valve 7.
Than prior art 1, prior art 2 is to utilize hydraulic oil that oil eliminator 3 separates as injection power, to make system oil return by the compressor oils in special-purpose injector 6 injection packages (full liquid) the formula evaporimeter 8.But in the prior art 2, utilized 3 magnetic valves and an injector that system oil return is controlled in the oil return system, structure is too complicated.
The utility model content
In view of this, main purpose of the present utility model is to provide a kind of simple in structure and screw type cold system and the control method thereof being convenient to control.
Technical scheme 1: a kind of screw type cold system, comprise screw compressor, condenser, evaporimeter, electric expansion valve, oil eliminator, the 1st magnetic valve, the 2nd magnetic valve, injector, the outlet of screw compressor is connected with the inlet of oil eliminator by the 1st pipeline, the refrigerant outlet of oil eliminator is connected with the inlet of condenser by the 2nd pipeline, the outlet of condenser is connected with the inlet of evaporimeter by the 3rd pipeline, and the outlet of evaporimeter is connected by the 4th pipeline with the inlet of screw compressor, and electric expansion valve is arranged in the 3rd pipeline, injector is arranged on the 4th pipeline, its high pressure port is connected with the oil return opening of oil eliminator by the 5th pipeline, and low-pressure port is connected with the oil return opening of evaporimeter by the 6th pipeline, and the 1st magnetic valve and the 2nd magnetic valve are separately positioned in the 5th pipeline and the 6th pipeline.
As from the foregoing, cold-producing medium is compressed in screw compressor behind the gas of HTHP by the 1st pipeline transmission to oil eliminator, in transmission course, compressor oil in the compressor also can flow with cold-producing medium, and entering oil eliminator, cold-producing medium and compressor oil are separated in oil eliminator.To condenser, the compressor oil of high pressure then enters into screw compressor by the 5th pipeline by the high pressure port of injector to cold-producing medium when the 1st magnetic valve is opened by the 2nd pipeline transmission.At this moment, if when the 2nd magnetic valve is in open mode, under the ejector action of the compressor oil of high pressure, the compressor oil in the inflow evaporator by injection in screw compressor.
Owing to utilize the compressor oil in the direct injection evaporimeter of compressor oil of high pressure, and utilize cold-producing medium to carry out injection in the prior art to compare the refrigeration or the heating efficiency that also can not reduce system not only simple in structure.
Technical scheme 2:, in the 5th pipeline and the 6th pipeline, also be separately installed with the 1st filter and the 2nd filter according to the described a kind of screw type cold of technical scheme 1 system.
Owing to be separately installed with the 1st filter and the 2nd filter in the 5th pipeline and the 6th pipeline, therefore, the impurity of sneaking into compressor oil is removed before returning screw compressor.
Technical scheme 3:, in the 3rd pipeline, device for drying and filtering is installed according to technical scheme 1 and 2 described a kind of screw type cold systems.
Owing in the 3rd pipeline, device for drying and filtering has been installed, can be before cold-producing medium enter evaporimeter, impurity screening effectively, the moisture in the absorption refrigeration agent is to guarantee the unimpeded and refrigeration system operate as normal of pipeline.
Technical scheme 4: according to technical scheme 1 and 2 described a kind of screw type cold systems, described screw compressor is semi-enclosed helical-lobe compressor.
Advantages such as semi-enclosed helical-lobe compressor has operational efficiency height, high compression ratio, vibration is little, noise is low, long service life.Therefore, except that the effect of technical scheme 1 and 2,, also can make the screw type cold system have characteristics such as operational efficiency height, long service life by using semi-enclosed helical-lobe compressor.
Technical scheme 5: according to technical scheme 1 and 2 described a kind of screw type cold systems, described evaporimeter is a flooded evaporator.
Because the cold-producing medium of flooded evaporator is in the pipe outside, the evaporation tube surface is that liquid is wetting, and surface coefficient of heat transfer is big, and therefore the heat exchange efficiency height can will wherein flow slower compressor oil injection in screw compressor when utilizing its heat exchange efficiency high.
Technical scheme 6: according to technical scheme 1 and 2 described a kind of screw type cold systems, described screw type cold system is the air-conditioning unit.
Because this screw type cold system is the air-conditioning unit, can obtain air-conditioning unit simple in structure and the efficient oil return of energy.
Description of drawings
Fig. 1 is the dry evaporator schematic diagram;
Fig. 2 is the flooded evaporator schematic diagram;
Fig. 3 is the system schematic of prior art 1;
Fig. 4 is the system schematic of prior art 2;
Fig. 5 is a screw type cold system schematic of the present utility model.
The specific embodiment
The embodiment that following basis is concrete is discussed screw type cold system of the present utility model and control method thereof.
Fig. 5 is a screw type cold system schematic of the present utility model.As shown in the figure, the screw type cold system comprises screw compressor 1, condenser 2, flooded evaporator 8, electric expansion valve 5, oil eliminator 3, the 1 magnetic valve 7a, the 2nd magnetic valve 7b.The outlet of screw compressor 1 is connected with the inlet of oil eliminator 3 by the 1st pipeline 10, cold-producing medium 12 outlets of oil eliminator 3 are connected with the inlet of condenser 2 by the 2nd pipeline 20, the outlet of condenser 2 is connected with the inlet of flooded evaporator 8 by the 3rd pipeline 30, electric expansion valve 5 and device for drying and filtering 4 are installed in the 3rd pipeline 30, the oil return opening of oil eliminator 3 is connected with the high pressure port of injector 6 by the 5th pipeline 50, the 1st magnetic valve 7a and the 1st filter 9a are installed in the 5th pipeline 50, the oil return opening of flooded evaporator 8 is connected with the low-pressure port of injector 6 by the 6th pipeline 60, and the 2nd magnetic valve 7b and the 2nd filter 9b are installed in the 6th pipeline 60.
Need experience following four cyclic processes during screw compressor 1 operation:
1, breathing process;
2, sealing and course of conveying;
3, compression and injection process;
4, exhaust process.
Wherein in the 3rd process and compression and injection process, helical-lobe compressor 1 is with cold-producing medium 12 boil down to high temperature and high pressure gas the time, compressor oil also can mix because of action of pressure sprays in the discharge chambe with high-temperature gas in the discharge chambe, enters circulating line then, i.e. the 1st and the 4th pipeline.By injection process, make and flow out the oil return of screw compression machine oil in helical-lobe compressor 1.
Oil return system in the present embodiment is by the 5th pipeline 50, the 6 pipelines 60, injector 6, the 1 magnetic valve 7a, and the 2nd magnetic valve 7b, the 1st filter 9a, the 2nd filter 9b constitutes.The 1st filter 9a is installed between the oil return opening and the 1st magnetic valve 7a of oil eliminator 3 described in the 5th pipeline 50, the 2nd filter 9b is installed between the oil return opening and the 2nd magnetic valve 7b of flooded evaporator 8 in the 6th pipeline 60, impurity when being used for eliminating oil return in the compressor oil that pipeline flows is to guarantee the normal use of the 2nd magnetic valve 7b and injector 6.
Device for drying and filtering 4 is installed between the outlet and electric expansion valve 5 of condenser 2 in the 3rd pipeline 30.At this device for drying and filtering 4 is installed and is filtered the moisture and the impurity of sneaking in the cold-producing medium effectively, to guarantee the unimpeded and refrigeration system operate as normal of pipeline; Device for drying and filtering 4 can also be used to collecting the solid impurity in refrigeration system and the compressor oil, and anti-locking system and pipeline and electric expansion valve 5 stop up, and guarantee that pipe-line system is unimpeded.
Flooded evaporator 8 used in the present embodiment is as shown in Figure 2 owing to heat exchanger tube 11 is immersed in the liquid cold-producing medium 12, still contain big quantity of fluid in the gas-liquid mixture after the heat absorption evaporation, thus in the flooded evaporator 8 damp steams of effusions after gas-liquid separation back into helical-lobe compressor 1.Flooded evaporator 8 since cold-producing medium 12 in heat exchanger tube 11 outsides, the evaporation tube surface is that liquid is wetting, surface coefficient of heat transfer is big, the heat exchange efficiency height.
As from the foregoing, under the compression of screw compressor 1, cold-producing medium is compressed to the gas of HTHP, transfers to oil eliminator 3 by the 1st pipeline 10, in transmission course, the compressor oil in the screw compressor 1 also can flow to oil eliminator 3 with cold-producing medium 12.Cold-producing medium 12 and compressor oil are separated in oil eliminator 3, isolated cold-producing medium transfers to condenser 2 by the 2nd pipeline 20, compressor oil then enters the 1st filter 9a by the 5th pipeline 50, enters injector 6 when the 1st magnetic valve 7a opens and get back in the helical-lobe compressor 1 after the 1st filter 9a filters.When carrying out this oil return process, cold-producing medium 12 becomes cryogenic high pressure after condenser 2 condensations liquid enters moisture and the contaminant filter that device for drying and filtering 4 is mingled with in can be with cold-producing medium 12 by device for drying and filtering 4 by the 3rd pipeline 30.Because device for drying and filtering 4 can not filter compressor oil, so the compressor oil that part does not obtain separating in oil eliminator 3 still can continue to enter flooded evaporator 8 by electric expansion valve 5 with cold-producing medium, the cold-producing medium of cryogenic high pressure is evaporated to gaseous state in flooded evaporator 8, in this process with heat exchanger tube in water generation heat exchange therefrom absorb heat, reach the purpose of refrigeration.Compressor oil in the flooded evaporator 8 can be by the 6th pipeline 60 behind the 2nd filter 9b, when opening, the 2nd magnetic valve 7b enters injector 6, under ejector action, get back to screw compressor 1 via the 4th pipeline 40, thereby enter next circulation from the high pressure compressed machine oil of the 5th pipeline.
In the process of whole refrigeration system operation, by controlling the oil return that the 1st magnetic valve 7a and the 2nd magnetic valve 7b control described refrigeration system respectively.The startup stage that the control of described refrigeration system comprising, operation phase and stop phase three phases.In this three phases, the control method of the 1st magnetic valve 7a and the 2nd magnetic valve 7b is as follows:
Described screw type cold system the startup stage, when screw compressor 1 is in compression and injection process, open the 1st magnetic valve 7a and the 2nd magnetic valve 7b, make the high pressure compressed machine oil of separating in the oil eliminator 3 enter screw compressor 1, and the compressor oil in the injection flooded evaporator 8 make it enter screw compressor 1 thus;
Described screw type cold system is when the operation phase, and according to the load of screw compressor 1, whether suction and discharge pressure reduction and screw compressor 1 inside oil starvation, determines the 2nd magnetic valve 7b to open or close.That is, when screw compressor 1 not at 100% load operation, or screw compressor 1 is at 100% load operation but suction and discharge pressure reduction is lower than 0.45MPa, or during inner oil starvation, keeps the open mode of the 1st magnetic valve 7a and the 2nd magnetic valve 7b; When screw compressor 1 runs to 100% load, and suction and discharge pressure reduction is more than 0.45MPa, and inside is during oil starvation, keeps the open mode of the 1st magnetic valve 7a and closes the 2nd magnetic valve 7b;
Described screw type cold system closes the 1st magnetic valve 7a and the 2nd magnetic valve 7b at stop phase.
Since the described screw compressor refrigeration system of present embodiment the startup stage, the 1st magnetic valve 7a and the 2nd magnetic valve 7b all are in open mode, be back to rapidly in the screw compressor 1 via the 5th pipeline 50 and the 6th pipeline 60 respectively with flooded evaporator 8 interior compressor oils in the oil eliminator 3, guarantee to have in the screw compressor 1 sufficient compressor oil to be used for starting screw compressor 1 and compressed refrigerant.When moving to 100% load and screw compressor 1, screw compressor 1 indicate the draught head of oil starvation not, air-breathing and exhaust when 0.45MPa is above, the 1st magnetic valve 7a continues to open, and the port of the compressor oil in the oil eliminator 3 by injector 6 is back in the screw compressor 1; And close the 2nd magnetic valve 7b this moment, prevent that the compressor oil in the flooded evaporator 8 is back in the screw compressor 1 by injector 6, therefore the cold-producing medium that can reduce effectively in the flooded evaporator 8 just is back in the screw compressor 1 by the 6th pipeline when not evaporating fully, influences refrigerating capacity.If in running, screw compressor 1 does not have 100% load operation or screw compressor at 100% load operation but suction and discharge pressure reduction is lower than 0.45MPa, or during inner oil starvation, keep the open mode of the 1st magnetic valve 7a and the 2nd magnetic valve 7b, compressor oil in the oil eliminator 3 is back in the screw compressor 1 by injector 6, and the compressor oil in the injection flooded evaporator 8 is back in the screw compressor 1 it rapidly, to guarantee in the screw compressor 1 enough compressor oils being arranged.When this refrigerating circuit unit was out of service, the 1st magnetic valve 7a and the 2nd magnetic valve 7b all were in closed condition, prevented that the compressor oil in the screw compressor 1 from outwards flowing.
Only be provided with the 1st magnetic valve 7a in the screw type cold of the present utility model as from the foregoing system and the 2nd magnetic valve 7b is used for oil return is controlled, not only simple in structure, be convenient to control, also can not influence the operation of screw compressor 1 when 100% load.Therefore, the described screw type cold of present embodiment system can be widely used in the air-conditioning unit.
The above only is preferred embodiment of the present utility model; not in order to restriction the utility model; all within spirit of the present utility model and principle, any modification of being done, be equal to replacement, improvement etc., all should be included within the protection domain of the present utility model.
Claims (6)
1. screw type cold system, comprise screw compressor, condenser, evaporimeter, electric expansion valve, oil eliminator, the 1st magnetic valve, the 2nd magnetic valve, injector, the outlet of screw compressor is connected with the inlet of oil eliminator by the 1st pipeline, cold-producing medium 12 outlets of oil eliminator are connected with the inlet of condenser by the 2nd pipeline, and the outlet of condenser is connected with the inlet of evaporimeter by the 3rd pipeline, and the outlet of evaporimeter is connected by the 4th pipeline with the inlet of screw compressor, electric expansion valve is arranged in the 3rd pipeline, it is characterized in that injector is arranged on the 4th pipeline, its high pressure port is connected with the oil return opening of oil eliminator by the 5th pipeline, low-pressure port is connected with the oil return opening of evaporimeter by the 6th pipeline, and the 1st magnetic valve and the 2nd magnetic valve are separately positioned in the 5th pipeline and the 6th pipeline.
2. a kind of screw type cold according to claim 1 system is characterized in that, also is separately installed with the 1st filter and the 2nd filter in the 5th pipeline and the 6th pipeline.
3. a kind of screw type cold according to claim 1 and 2 system is characterized in that, in the 3rd pipeline device for drying and filtering is installed.
4. a kind of screw type cold according to claim 1 and 2 system is characterized in that described screw compressor is semi-enclosed helical-lobe compressor.
5. a kind of screw type cold according to claim 1 and 2 system is characterized in that described evaporimeter is a flooded evaporator.
6. a kind of screw type cold according to claim 1 and 2 system is characterized in that, described screw type cold system is the air-conditioning unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206181525U CN201885488U (en) | 2010-11-18 | 2010-11-18 | Screw type cooling system and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206181525U CN201885488U (en) | 2010-11-18 | 2010-11-18 | Screw type cooling system and control method thereof |
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| Publication Number | Publication Date |
|---|---|
| CN201885488U true CN201885488U (en) | 2011-06-29 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010206181525U Expired - Fee Related CN201885488U (en) | 2010-11-18 | 2010-11-18 | Screw type cooling system and control method thereof |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102466376A (en) * | 2010-11-18 | 2012-05-23 | 海尔集团公司 | Screw-type refrigerating system and control method thereof |
| CN103375936A (en) * | 2012-04-11 | 2013-10-30 | 珠海格力电器股份有限公司 | Screw unit cooling system |
| CN104380013A (en) * | 2012-03-22 | 2015-02-25 | 特灵国际有限公司 | Electronics cooling using lubricant return for a shell-and-tube style evaporator |
-
2010
- 2010-11-18 CN CN2010206181525U patent/CN201885488U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102466376A (en) * | 2010-11-18 | 2012-05-23 | 海尔集团公司 | Screw-type refrigerating system and control method thereof |
| CN104380013A (en) * | 2012-03-22 | 2015-02-25 | 特灵国际有限公司 | Electronics cooling using lubricant return for a shell-and-tube style evaporator |
| CN104380013B (en) * | 2012-03-22 | 2017-02-22 | 特灵国际有限公司 | Electronics cooling using lubricant return for a shell-and-tube style evaporator |
| CN103375936A (en) * | 2012-04-11 | 2013-10-30 | 珠海格力电器股份有限公司 | Screw unit cooling system |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110629 Termination date: 20161118 |
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| CF01 | Termination of patent right due to non-payment of annual fee |