CN102467135A - Refrigerant liquid level control method for flooded evaporator - Google Patents
Refrigerant liquid level control method for flooded evaporator Download PDFInfo
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- CN102467135A CN102467135A CN2010105769430A CN201010576943A CN102467135A CN 102467135 A CN102467135 A CN 102467135A CN 2010105769430 A CN2010105769430 A CN 2010105769430A CN 201010576943 A CN201010576943 A CN 201010576943A CN 102467135 A CN102467135 A CN 102467135A
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- 239000003507 refrigerant Substances 0.000 title claims abstract description 131
- 239000007788 liquid Substances 0.000 title claims abstract description 72
- 238000000034 method Methods 0.000 title claims abstract description 42
- 238000001704 evaporation Methods 0.000 claims abstract description 25
- 230000008020 evaporation Effects 0.000 claims abstract description 20
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 159
- 238000013459 approach Methods 0.000 claims description 42
- 230000009183 running Effects 0.000 claims description 19
- 230000007935 neutral effect Effects 0.000 claims description 11
- 230000009471 action Effects 0.000 claims description 9
- 238000012937 correction Methods 0.000 claims description 2
- 239000005457 ice water Substances 0.000 abstract 3
- 230000005494 condensation Effects 0.000 abstract 1
- 238000009833 condensation Methods 0.000 abstract 1
- 238000004378 air conditioning Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 238000007710 freezing Methods 0.000 description 2
- 230000008014 freezing Effects 0.000 description 2
- 230000000750 progressive effect Effects 0.000 description 2
- 241001131796 Botaurus stellaris Species 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- JEGUKCSWCFPDGT-UHFFFAOYSA-N h2o hydrate Chemical compound O.O JEGUKCSWCFPDGT-UHFFFAOYSA-N 0.000 description 1
- 230000035800 maturation Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002715 modification method Methods 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
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Abstract
The invention discloses a refrigerant liquid level control method of a flooded evaporator, which measures the ice water inlet temperature, the ice water outlet temperature and the refrigerant evaporation pressure value of an evaporator, the refrigerant condensation pressure value of a condenser and the refrigerant discharge temperature of a compressor to obtain a compressor discharge temperature error value and an evaporator arithmetic mean temperature difference error value, and a controller adjusts the opening degree of an electronic expansion valve according to the discharge temperature error value and the arithmetic mean temperature difference error value to achieve the optimal refrigerant flow and liquid level control, thereby effectively playing the heat exchange area of the evaporator, improving the evaporation temperature and further improving the partial load efficiency of an ice water machine.
Description
Technical field
The present invention relates to a kind of flooded evaporator refrigerant liquid level controlling method; It provides the actual frozen water of a kind of measurement to go into water outlet temperature approach, refrigerant spue temperature, refrigerant evaporation force value and refrigerant condensing pressure value; And draw actual and an expectation spue temperature error values and actual and an expectation arithmetic mean temperature difference error amount; And then according to the aperture of this error amount adjustment electronic expansion valve; With the refrigerant liquid level of control evaporator, and the heat exchange area of evaporator can be effectively brought into play, and evaporating temperature can be promoted.
Background technology
In recent years the technology of refrigerating and air conditioning has leveled off to maturation, the key concept of right freezing or air-conditioning, and it is to utilize refrigerant and liquid heat-exchange, to promote or to reduce the temperature of liquid, perhaps, reduces or promotes the temperature of refrigerant, and then reach air-conditioning or freezing purpose.
And in heat exchanging process more common device; It is a full-liquid type refrigerant system; This full-liquid type refrigerant system has a compressor, a condenser, an electronic expansion valve and a flooded evaporator, and compressor has an inlet end and an endpiece, and endpiece connects condenser with a pipeline; Condenser connects electronic expansion valve with a pipeline; Electronic expansion valve is that a pipeline connects flooded evaporator, and flooded evaporator is to connect compressor with a pipeline, in flooded evaporator, is provided with a liquid level sensor in addition.
The liquid level of refrigerant is under optimum condition in the flooded evaporator; It just covers and is arranged in the most upward row's copper pipe of flooded evaporator; So that refrigerant carries out heat interchange with the liquid that flows in the copper pipe; This liquid can be water, oil or bittern etc., in order effectively to control the refrigerant liquid level, in the prior art to adopt liquid level sensor, the pressure of detecting condenser and three kinds of common modes of progressive temperature.
The mode of first kind of liquid level sensor, it cooperates liquid level sensor with electronic expansion valve, is used as controlling the method for refrigerant liquid level; Under fully loaded standard conditions, i.e. compressor 100% running, liquid level sensor can very be controlled the refrigerant liquid level accurately; But in virtual condition; Compressor might have only fractional load, because refrigerant liquid level and actual liquid level that liquid level sensor sets, the two has great difference; Moreover the evaporation of refrigerant boiling also can increase whole variable, and makes the non-optimal liquid level place that is in of refrigerant, so evaporator can't effectively bring into play its best function, and causes evaporator refrigerant temperature and compressor operation efficient to improve; Again one, it is relatively poor that the liquid level of existing liquid level sensor is resolved precision, and expense is higher.
Second kind of mode of utilizing the detecting condenser pressure, it converts the pressure of being detected to temperature, adds a temperature gap; With the temperature that spues as a refrigerant, and then control refrigerant liquid level, but the height of refrigerant liquid level receives the influence of evaporator refrigerant temperature; And that the temperature variation that spues of refrigerant can be said is very little, and this variable quantity adds that the error amount of temperature detecting causes the refrigerant liquid level to be difficult to accurate control, in addition; Extraneous factor also can cause erroneous judgement; Hot gas like the external world gets in the evaporator, causes evaporating temperature and spues the too high illusion of temperature, and make the difficulty that increases control; Moreover the pressure of detecting condenser also can't be applied to the demand of the optimal liquid level under fractional load or the low condensing pressure condition.
The third adopts progressive temperature controlling mode; It utilizes and keeps frozen water leaving water temperature and the fixing temperature gap of evaporator refrigerant temperature; Reach the purpose of refrigerant liquid level control, but still can't be applicable to the fractional load condition time, the demand of refrigerant under optimal liquid level and optimal evaporation temperature conditions.
Comprehensively above-mentioned; The refrigerant liquid level controlling method of existing three kinds of common simple target setting values; It has respectively, and expense is higher, liquid level parsing precision is relatively poor, can't reach effective control section loading condition in preferable refrigerant liquid level, improves the space so existing refrigerant liquid level controlling method still has.
Summary of the invention
Because above-mentioned shortcoming; The object of the present invention is to provide a kind of flooded evaporator refrigerant liquid level controlling method, the frozen water that its utilization sets is gone into out water temperature difference, measured actual frozen water and is gone into water outlet temperature approach, refrigerant spue temperature, refrigerant evaporation force value and refrigerant condensing pressure value, with the aperture of adjustment electronic expansion valve; And then the refrigerant liquid level in the control evaporator; And can effectively bring into play the heat exchange area of evaporator, and can promote evaporating temperature, so that evaporator is able to the evaporator refrigerant temperature running down in the best; Promote the running efficiency under the frozen water machine part loading condition, and also have with low cost and the high advantage of liquid level control precision.
In order to reach above-mentioned purpose, technological means of the present invention is to provide a kind of flooded evaporator refrigerant liquid level controlling method, and its step comprises as follows:
A, setting pacing items: set a plurality of temperature approach and a plurality of modified value.
B, measuring temperature and pressure: measure a frozen water and go into coolant-temperature gage, a frozen water leaving water temperature, a refrigerant evaporation force value, a refrigerant condensing pressure value and the refrigerant temperature value that spues.
C, error of calculation value:, and draw error amount according to the data of this steps A and B gained.
The aperture of D, control electronic expansion valve: according to the error amount of this step C gained, to control the aperture of this electronic expansion valve.
In the aforesaid steps A; Temperature approach and modified value are that specified arithmetic mean temperature difference, a specified frozen water of an evaporator gone into the neutral band of water outlet temperature approach, an arithmetic mean temperature difference modified value, an arithmetic mean temperature difference value and the temperature modified value that spues; Arithmetic mean temperature modified value is between-0.5～0.5, and the temperature that spues modified value is between 0～5.And specified arithmetic mean temperature difference value, specified frozen water are gone into water outlet temperature approach, arithmetic mean temperature difference modified value and the temperature modified value that spues is set in the controller; And electronic expansion valve can be 50～100% in the setting value that the initial opening of compressor start running sets.
Aforesaid step B; It measures frozen water respectively with a plurality of temperature sensors and goes into coolant-temperature gage, frozen water leaving water temperature and the refrigerant temperature that spues, and measures the refrigerant condensing pressure value of discharge pipe of refrigerant evaporation force value and condenser or compressor of the air intake duct of evaporator or compressor in addition respectively with a plurality of pressure transducers.Temperature sensor and pressure transducer are gone into spue temperature, refrigerant evaporation force value and refrigerant condensing pressure value of coolant-temperature gage, frozen water leaving water temperature, refrigerant with the frozen water that is measured and are sent controller to.
Aforesaid step C, it further has:
The spue expectation value of arithmetic mean temperature difference of temperature and evaporator of C1, the expectation of calculating compressor: according to refrigerant evaporation force value, refrigerant condensing pressure value and the temperature modified value that spues, and the expectation that the draws compressor temperature that spues; And go into the temperature approach, this arithmetic mean temperature difference modified value and this specified arithmetic mean temperature difference of coolant-temperature gage and frozen water leaving water temperature according to frozen water, and draw the expectation arithmetic mean temperature difference value of this evaporator.
C2, calculating evaporator refrigerant temperature:, and draw an evaporator refrigerant temperature according to the refrigerant evaporation force value.
C3, the actual arithmetic mean temperature difference of calculating: go into coolant-temperature gage, frozen water leaving water temperature and evaporator refrigerant temperature according to frozen water, and draw an actual arithmetic mean temperature difference value.
C4, calculate the spue error amount of temperature and arithmetic mean temperature difference of refrigerant:, and draw the actual and expectation temperature error values that spues according to refrigerant temperature and the expectation refrigerant temperature that spues that spues; And according to actual arithmetic mean temperature difference value and expectation arithmetic mean temperature difference value, and draw an actual and expectation arithmetic mean temperature difference error amount.
In step C1, the refrigerant evaporation force value abbreviate RSEP as, the refrigerant condensing pressure value abbreviate RSCP as, the temperature that spues modified value abbreviate C as
SHDT, the spue SHDT that abbreviates as of temperature of expectation
Exp, the temperature calculation formula of expecting to spue is: SHDT
Exp=a+b * (RSCP)+c * (RSCP)
2+ d * (RSEP)+C
SHDT, and a, b, c, d are constant.
In step C1, frozen water is gone into the CWRT that abbreviates as of coolant-temperature gage, the frozen water leaving water temperature abbreviate CWLT as, specified frozen water is gone into out water temperature difference and is abbreviated Δ T as, the arithmetic mean temperature difference modified value abbreviate C as
Δ tm, specified arithmetic mean temperature difference abbreviate Δ t as
m, expectation arithmetic mean temperature difference value abbreviate Δ t as
M (exp), the computing formula of expectation arithmetic mean temperature difference value is: Δ t
M (exp)=(CWRT-CWLT)/Δ T * Δ t
m+ C
Δ tm
In step C2, evaporator refrigerant temperature abbreviate RSET as, the computing formula of evaporator refrigerant temperature is: RSET=a1+b1 * (RSEP)+c1 * (RSEP)
0.5, wherein a1, b1, c1 are constant.
In step C3, the abbreviation Δ t of actual arithmetic mean temperature difference value
M (real), the computing formula of actual arithmetic mean temperature difference value is: Δ t
M (real)=[(CWRT+CWLT)/2]-RSET.
In step C4, actual and the expectation temperature error values that spues abbreviates Err as
Δ SHDT, the spue computing formula of temperature error values of actual and expectation is: Err
Δ SHDT=SHDT-SHDT
ExpActual and expectation arithmetic mean temperature difference error amount abbreviates Err as
Δ tm, actual computing formula with expectation arithmetic mean temperature difference error amount is: Err
Δ tm=Δ t
M (exp)-Δ t
M (real)
Aforesaid step D, it further has:
D1, judge should reality with expectation spue temperature error values whether smaller or equal to or greater than a setting value: setting value is zero; When temperature error values is smaller or equal to setting value if actual and expectation spues; Open the hydraulic pressure protection flag that contracts, reduce the aperture of this electronic expansion valve; When temperature error values is greater than setting value if actual and expectation spue, closes this hydraulic pressure protection flag that contracts, and get into next step.
Whether D2, judge should reality to be greater than or less than with expectation arithmetic mean temperature difference error amount and equal the neutral band of arithmetic mean temperature difference value: if smaller or equal to the neutral band of arithmetic mean temperature difference value, then electronic expansion valve is kept existing aperture, and gets back to step B; If, then adjust the aperture of electronic expansion valve, and get back to step B greater than the neutral band of arithmetic mean temperature difference value.
As stated, further have the step whether a compressor turns round between step B and the step C1,, then finish if compressor does not turn round; If compressor operation then carries out step C1.
As stated; Whether further have a compressor between step C4 and the step D1 and turn round and be greater than or less than the step that equals a special time, special time, if compressor operation is smaller or equal to special time if being 3～5 minutes; The aperture of electronic expansion valve is 50～100%, then gets back to step B; If compressor operation greater than special time, then carries out step D1.
Aforesaid step D1, electronic expansion valve reduces 5% aperture one by one in a firm output cycle, and the restriction of electronic expansion valve maximum opening equals the present aperture of electronic expansion valve.
Contract protection during flag when closing this hydraulic pressure, and the electronic expansion valve maximum opening is removed, and gets into this step D2.
Aforesaid step D2, in greater than the neutral band of arithmetic mean temperature difference value the time, controller calculates the expectation aperture and action step number of electronic expansion valve, with the aperture of adjustment electronic expansion valve.
The action step number on the occasion of the time then increase the aperture of electronic expansion valve, and get back to this step B; The action step number then reduces the aperture of electronic expansion valve when being negative value, and gets back to this step B.
Further have one among aforesaid steps A and the step B and revise the method that this specified frozen water is gone into the water outlet temperature approach, its step includes:
One, the frozen water of setting rated full load is gone into the water outlet temperature approach: set a specified frozen water and go into the water outlet temperature approach, specified frozen water is gone into the specified frozen water that the water outlet temperature approach equals in the steps A and is gone into the water outlet temperature approach.
Two, whether compressor turns round: if compressor does not turn round, promptly finish; If compressor operation then carries out next step.
Three, whether compressor reaches full carrier strip spare: if compressor operation does not reach full carrier strip spare, then do not revise, then to step 2; If compressor operation reaches full carrier strip spare, then carry out next step.
Four, calculate compressor and go into the water outlet temperature approach in the frozen water of full carrier strip spare running: controller is gone into coolant-temperature gage and frozen water leaving water temperature according to frozen water, draws the frozen water of compressor when full carrier strip spare and goes into the water outlet temperature approach;
Five, automatically whether judgement is readjusted specified frozen water and is gone into out the water temperature difference setting value: go into out water temperature difference and frozen water is gone into the water outlet temperature approach according to specified frozen water; And draw an error amount, if the absolute value of error amount during smaller or equal to a setting value, then is failure to actuate; Then to step 2, setting value is 5%; If absolute value greater than this setting value, then carries out next step;
Six, judge whether the number of times that recurs is equal to or less than a fixed number of times: this fixed number of times is five～ten times; If absolute value equals this fixed number of times greater than the frequency of this setting value; Then frozen water is gone into the water outlet temperature approach and is replaced specified frozen water and go into out water temperature difference, and gets back to step 2; If absolute value, is not then revised less than this fixed number of times greater than the frequency of setting value, and to step 2.
Frozen water is gone into the abbreviation Δ T of water outlet temperature approach
Real, the computing formula that frozen water is gone into the water outlet temperature approach is: Δ T
Real=CWRT-CWLT; What specified frozen water was gone into the water outlet temperature approach abbreviates Δ T as
Setpoint, the computing formula of error amount is: ABS (Δ
Real-Δ T
Setpoint)/Δ T
Setpoint>=5%.
Beneficial functional of the present invention is: comprehensive above-mentioned method; Its mainly be according to actual and expectation spue temperature error values and actual with expect the arithmetic mean temperature difference error amount; With the aperture of adjustment electronic expansion valve, and then control cold medium flux, and can effectively bring into play the heat exchange area of evaporator; And can promote evaporating temperature; So that the refrigerant of evaporator can be positioned at optimal liquid level, and make evaporator in the running of the evaporator refrigerant temperature of the best, expense is lower so the present invention has, liquid level parsing precision is good, during the controllable portion loading condition refrigerant in the advantage of optimal liquid level.
Describe the present invention below in conjunction with accompanying drawing and specific embodiment, but not as to qualification of the present invention.
Description of drawings
Fig. 1 is the synoptic diagram of the frozen water machine of application flooded evaporator refrigerant liquid level controlling method of the present invention;
Fig. 2 A and Fig. 2 B are the schematic flow sheet of flooded evaporator refrigerant liquid level controlling method of the present invention;
Fig. 3 is the schematic flow sheet that the frozen water water outlet temperature approach of rated full load is set in correction of the present invention.
Wherein, Reference numeral
10 controllers
11 evaporators
110 temperature sensors
111 temperature sensors
112 pressure transducers
12 compressors
120 temperature sensors
121 compressor suction ducts
122 compressor discharge pipes
13 condensers
130 pressure transducers
14 electronic expansion valves
20～293 steps
30～351 steps
Embodiment
Below in conjunction with accompanying drawing and specific embodiment technical scheme of the present invention being carried out detailed description, further understanding the object of the invention, scheme and effect, but is not the restriction as accompanying claims protection domain of the present invention.
See also shown in Fig. 1, Fig. 2 A and Fig. 2 B, the present invention is a kind of flooded evaporator refrigerant liquid level controlling method, and its step includes:
A, setting pacing items 20: in a controller 10, set an evaporator 11, the specified arithmetic mean temperature difference value when the rated full load operating condition (hereinafter to be referred as, Δ t
m) go into water outlet temperature approach (hereinafter to be referred as, Δ T) with a specified frozen water, in controller 10, set an arithmetic mean temperature difference modified value in addition (hereinafter to be referred as, C
Δ tm), the neutral band of an arithmetic mean temperature difference value (hereinafter to be referred as, dead band) and spues the temperature modified value (hereinafter to be referred as, C
SHDT), C wherein
Δ tmBetween-0.5～0.5, C
SHDTBetween 0～5; This specified frozen water is gone into out water temperature difference and can be changed according to the frozen water flow, and this specified frozen water is gone into out the change setting means of water temperature difference, states after asking for an interview.And the setting value that the initial opening that electronic expansion valve 14 starts running at compressor 12 sets can be 50～100%.
B, measuring temperature and pressure 21: the frozen water that uses a temperature sensor 110 to measure evaporators 11 go into coolant-temperature gage (hereinafter to be referred as, CWRT), other use a temperature sensor 111 measure evaporators 11 the frozen water leaving water temperature (hereinafter to be referred as, CWLT); Use a pressure transducer 112 measure the air intake duct 121 of evaporators 11 or compressor the refrigerant evaporation force value (hereinafter to be referred as, RSEP); The refrigerant that uses a temperature sensor 120 to measure compressors 12 spue temperature (hereinafter to be referred as, SHDT); Use a pressure transducer 130 measure the discharge pipe 122 of condensers 13 or compressor the refrigerant condensing pressure value (hereinafter to be referred as, RSCP); Send CWRT, CWLT, RSEP, SHDT and RSCP to controller 10.
Whether C, compressor 12 turn round 22: if compressor 12 does not turn round, then electronic expansion valve 14 apertures are 0%220, and finish 221; If compressor 12 runnings then continue to next step.
The spue expectation arithmetic mean temperature difference value 23 of temperature and evaporator 11 of D, the expectation refrigerant that calculates compressor 12: controller 10 is according to RSEP, RSCP and C
SHDT, the temperature and the expectation refrigerant that draws compressor 12 spues (hereinafter to be referred as, SHDT
Exp), computing formula is: SHDT
Exp=a+b * (RSCP)+c * (RSCP)
2+ d * (RSEP)+C
SHDT, wherein a, b, c, d are constant.Controller 10 is according to CWRT, CWLT, Δ T, C
Δ tmWith Δ t
m, and the expectation arithmetic mean temperature difference value that draws evaporator 11 is (hereinafter to be referred as, Δ t
M (exp)), computing formula is: Δ t
M (exp)=(CWRT-CWLT)/Δ T * Δ t
m+ C
Δ tm
E, calculate evaporator refrigerant temperature 24: controller 10 is according to RSEP, and draw an evaporator refrigerant temperature (hereinafter to be referred as, RSET), computing formula is: RSET=a1+b1 * (RSEP)+c1 * (RSEP)
0.5, wherein a1, b1, c1 are constant.
F, calculate actual arithmetic mean temperature difference value 25: controller 10 is according to CWRT, CWLT and RSET, and draws an actual arithmetic mean temperature difference value (hereinafter to be referred as, Δ t
M (real)), computing formula is: Δ t
M (real)=[(CWRT+CWLT)/2]-RSET.
G, calculate the spue error amount 26 of temperature and arithmetic mean temperature difference value of refrigerant: controller 10 is according to SHDT and SHDT
Exp, spue temperature error values (hereinafter to be referred as, Err and draw actual and an expectation
Δ SHDT), computing formula is: Err
Δ SHDT=SHDT-SHDT
ExpController 10 is according to Δ t
M (exp)With Δ t
M (real), and draw actual and an expectation arithmetic mean temperature difference error amount (hereinafter to be referred as, Err
Δ tm), computing formula is: Err
Δ tm=Δ t
M (exp)-Δ t
M (real)
Whether H, compressor 12 turn round to be greater than or less than equals a special time 27: if compressor 12 runnings are smaller or equal to a special time; The aperture of electronic expansion valve 14 is 50～100%270; Then get back to above-mentioned step B 271, whole steps again, this special time is 3～5 minutes; If when compressor 12 turns round greater than this special time, then carry out next step.
I, judgement Err
Δ SHDTWhether smaller or equal to or greater than a setting value 28: controller 10 is to Err
Δ SHDTJudge, whether Err
Δ SHDTBe greater than or less than and equal a setting value, this setting value can be zero, if Err
Δ SHDTSmaller or equal to zero the time, open the hydraulic pressure protection flag 280 that contracts, electronic expansion valve 14 reduces 5% aperture 281 one by one in a firm output cycle, to carry out the protection flow process that a hydraulic pressure contracts, until SHDT greater than SHDT
Exp, i.e. electronic expansion valve 14 maximum openings restriction equals electronic expansion valve 14 present apertures 282, and gets back to step B283;
If, Err
Δ SHDTGreater than zero the time, then close the hydraulic pressure protection flag 284 that contracts, electronic expansion valve maximum opening restriction cancellation 285, and get into next step.
J, judgement Err
Δ tmAbsolute value whether smaller or equal to or greater than dead band 29: if during smaller or equal to dead band, electronic expansion valve 14 is kept existing aperture 290, and gets back to step B 283;
If during greater than dead band; Controller 10 calculates the expectation aperture and action step number 291 of electronic expansion valve 14; With the aperture of adjustment electronic expansion valve 14, if the action step number on the occasion of the time then increase the aperture 292 of electronic expansion valve 14, and get back to step B283;
If then reduce the aperture 293 of electronic expansion valve 14 during action step number negative value, and return above-mentioned step B283.
Get back to the purpose of step B, be the repetition whole steps, situation about taking place repeatedly with the protection flow process of avoiding hydraulic pressure to contract.
Though can be by above-mentioned design temperature, measure actual pressure and convert temperature into and measure actual temperature after; Controller 10 is according to aforesaid data and modified value; Whether decision will adjust the aperture of electronic expansion valve 14 again, with the running efficiency of effective lifting frozen water machine under the fractional load condition and best refrigerant liquid level.But the frozen water fluctuations in discharge can change frozen water goes into the water outlet temperature approach; It can cause the Δ T that sets at first possibly have great error amount; And can cause the aperture adjustment of electronic expansion valve 14 improper; Automatically revise so Δ T must go into out temperature approach according to actual frozen water, this modification method is to be applied in the above-mentioned steps A and B, and the step of this revised law is following:
One, the frozen water of setting the rated full load operating condition is gone into water outlet temperature approach 30: like above-mentioned steps A, set a specified frozen water and go into the water outlet temperature approach (hereinafter to be referred as, Δ T
Setpoint), in the Δ T described in this step
SetpointEqual above-mentioned Δ T.
Two, whether compressor 12 turns round 31: if compressor 12 does not turn round, promptly finish 310; If next step is carried out in compressor 12 runnings.
Three, whether compressor reaches full carrier strip spare 32: if compressor 12 running does not reach full carrier strip spare, and promptly 100%, then do not revise 320, and to step 2 351; If compressor 12 runnings reach full carrier strip spare, then carry out next step.
Four, calculate compressor 12 and go into water outlet temperature approach 33 in the frozen water of full carrier strip spare running: controller 10 is according to CWRT and CWLT, goes into the water outlet temperature approach (hereinafter to be referred as, Δ T and draw the frozen water of compressor 12 when full carrier strip spare running
Real), computing formula is: Δ T
Real=CWRT-CWLT.
Five, automatically whether judgement is readjusted specified frozen water and gone into out water temperature difference setting value 34: controller 10 is according to Δ T
SetpointWith Δ T
Real, and draw an error amount, if the absolute value of this error amount is during smaller or equal to a setting value, this setting value can be 5%, does not then revise 320, and to step 2 351, computing formula is: ABS (Δ T
Real-Δ T
Setpoint)/Δ T
Setpoint>=5%; If this absolute value greater than this setting value, then carries out next step.
Six, judge whether the number of times recur is equal to or less than a fixed number of times 35: this fixed number of times can be five～ten times, if the absolute value of step 5 is greater than this setting value, but frequency does not then revise 320 less than this fixed number of times, and to step 2 351; Equal this fixed number of times as if frequency, then Δ T
SetpointEqual Δ T
Real350, promptly Δ Treal is replaced in the Δ T that step 1 sets, and returns step 2 351, to repeat whole steps.
Comprehensively above-mentioned, the present invention is according to Δ T, Δ t
m, C
Δ tm, dead band, C
SHDT, CWRT, CWRT, RSEP, SHDT, RSCP, SHDT
Exp, Δ t
M (exp), RSET, Δ t
M (real), Err
Δ SHDT, Err
Δ tm, and whether decision will adjust the aperture of electronic expansion valve 14, to promote the running efficiency of frozen water machine; And Δ T can be with virtual condition, and revises, so that the aperture of electronic expansion valve 14 can be adjusted in response to virtual condition; And then the control cold medium flux, so that the refrigerant of evaporator 11 can be positioned at optimal liquid level, and can effectively bring into play the heat exchange area of evaporator 11; And can promote evaporating temperature, and make the evaporator refrigerant temperature running of evaporator 11 in the best.
Certainly; The present invention also can have other various embodiments; Under the situation that does not deviate from spirit of the present invention and essence thereof; Those of ordinary skill in the art work as can make various corresponding changes and distortion according to the present invention, but these corresponding changes and distortion all should belong to the protection domain of the appended claim of the present invention.
Claims (23)
1. the control method of a flooded evaporator refrigerant liquid level is characterized in that, its step includes:
A, setting pacing items: set a plurality of temperature approach and a plurality of modified value;
B, measuring temperature and pressure: measure a frozen water and go into coolant-temperature gage, a frozen water leaving water temperature, a refrigerant evaporation force value, a refrigerant condensing pressure value and the refrigerant temperature value that spues;
C, error of calculation value:, and draw error amount according to the data of this steps A and B gained;
The aperture of D, control electronic expansion valve: according to the error amount of this step C gained, to control the aperture of this electronic expansion valve.
2. the control method of flooded evaporator refrigerant liquid level as claimed in claim 1; It is characterized in that temperature approach described in this steps A and modified value are that specified arithmetic mean temperature difference value, a specified frozen water of an evaporator gone into the neutral band of water outlet temperature approach, an arithmetic mean temperature difference modified value, an arithmetic mean temperature difference value and the temperature modified value that spues; And this electronic expansion valve is 50～100% in the setting value that the initial opening of compressor start running sets;
Among this step B, its frozen water that measures an evaporator is gone into coolant-temperature gage and frozen water leaving water temperature; And the refrigerant that measures the compressor temperature value that spues;
Among this step C; It further has: the spue expectation value of arithmetic mean temperature difference value of temperature and evaporator of C1, the expectation of calculating compressor: according to this refrigerant evaporation force value, this refrigerant condensing pressure value and this temperature modified value that spues; The temperature and the expectation that draws this compressor spues; And go into coolant-temperature gage, this frozen water leaving water temperature, this specified frozen water according to this frozen water and go into water outlet temperature approach, this arithmetic mean temperature difference modified value and this specified arithmetic mean temperature difference value, and draw the expectation arithmetic mean temperature difference value of this evaporator; C2, calculating evaporator refrigerant temperature:, and draw an evaporator refrigerant temperature according to this refrigerant evaporation force value; C3, the actual arithmetic mean temperature difference value of calculating: go into coolant-temperature gage, this frozen water leaving water temperature and this evaporator refrigerant temperature according to this frozen water, and draw an actual arithmetic mean temperature difference value; C4, calculate the spue error amount of temperature and arithmetic mean temperature difference value of refrigerant: according to this refrigerant temperature and this expectation refrigerant temperature that spues that spues; And draw actual and the expectation temperature error values that spues; And according to this actual arithmetic mean temperature difference value and this expectation arithmetic mean temperature difference value, and draw an actual and expectation arithmetic mean temperature difference value;
Among this step D; It further has: D1, judge should reality with expectation spue temperature error values whether smaller or equal to or greater than a setting value: spue temperature error values during as if this reality and expectation smaller or equal to this setting value; Open the hydraulic pressure protection flag that contracts, reduce the aperture of this electronic expansion valve; When temperature error values is greater than this setting value if this reality and expectation spue, close this hydraulic pressure contract protection flag and entering next step; Whether D2, judge should reality to be greater than or less than with expectation arithmetic mean temperature difference error amount and equal the neutral band of this arithmetic mean temperature difference value: if smaller or equal to the neutral band of this arithmetic mean temperature difference value, then this electronic expansion valve is kept existing aperture, and gets back to this step B; If, then adjust the aperture of this electronic expansion valve, and get back to this step B greater than the neutral band of this arithmetic mean temperature difference value.
3. the control method of flooded evaporator refrigerant liquid level as claimed in claim 2 is characterized in that, among this step C1, this refrigerant evaporation force value abbreviate RSEP as, this refrigerant condensing pressure value abbreviate RSCP, the C that abbreviates as of this temperature modified value that spues as
SHDT, the spue SHDT that abbreviates as of temperature of this expectation
Exp, this expectation temperature calculation formula that spues is: SHDT
Exp=a+b * (RSCP)+c * (RSCP)
2+ d * (RSEP)+CSHDT}, and a, b, c, d are constant.
4. the control method of flooded evaporator refrigerant liquid level as claimed in claim 3 is characterized in that, in this step C1, this frozen water is gone into the CWRT that abbreviates as of coolant-temperature gage, this frozen water leaving water temperature abbreviate CWLT as, this arithmetic mean temperature difference modified value abbreviate C as
Δ tm, this specified arithmetic mean temperature difference abbreviate Δ t as
m, this expectation arithmetic mean temperature difference value abbreviate Δ t as
M (exp), the computing formula of this expectation arithmetic mean temperature difference value is: Δ t
M (exp)=(CWRT-CWLT)/Δ T * Δ t
m+ C
Δ tm
5. the control method of flooded evaporator refrigerant liquid level as claimed in claim 4 is characterized in that, in this step C2, this evaporator refrigerant temperature abbreviate RSET as, the computing formula of this evaporator refrigerant temperature is: RSET=a1+b1 * (RSEP)+c1 * (RSEP)
0.5, wherein a1, b1, c1 are constant.
6. the control method of flooded evaporator refrigerant liquid level as claimed in claim 5 is characterized in that, in this step C3, and the abbreviation Δ t of this actual arithmetic mean temperature difference value
M (real), the computing formula of this actual arithmetic mean temperature difference value is: Δ t
M (real)=[(CWRT+CWLT)/2]-RSET.
7. the control method of flooded evaporator refrigerant liquid level as claimed in claim 6 is characterized in that, in this step C4, this reality and the expectation temperature error values that spues abbreviates Err as
Δ SHDT, the spue computing formula of temperature error values of this reality and expectation is: Err
Δ SHDT=SHDT-SHDT
ExpThis reality abbreviates Err as with expectation arithmetic mean temperature difference error amount
Δ tm, this reality with the computing formula of expectation arithmetic mean temperature difference error amount is: Err
Δ tm=Δ t
M (exp)-Δ t
M (real)
8. the control method of flooded evaporator refrigerant liquid level as claimed in claim 7 is characterized in that, this arithmetic mean temperature modified value is between-0.5～0.5, and this spues the temperature modified value between 0～5.
9. the control method of flooded evaporator refrigerant liquid level as claimed in claim 2; It is characterized in that; Among this step B; It measures this frozen water respectively with a plurality of temperature sensors and goes into coolant-temperature gage, this frozen water leaving water temperature and this refrigerant temperature that spues; In addition measure this refrigerant evaporation force value and this refrigerant condensing pressure value respectively with a plurality of pressure transducers, this temperature sensor and this pressure transducer are gone into spue temperature, this refrigerant evaporation force value and this refrigerant condensing pressure value of coolant-temperature gage, this frozen water leaving water temperature, this refrigerant with this frozen water that is measured and are sent a controller to.
10. the control method of flooded evaporator refrigerant liquid level as claimed in claim 9; It is characterized in that; This pressure transducer measures the refrigerant condensing pressure value of the discharge pipe of this condenser or this compressor, and this pressure transducer system measures the refrigerant evaporation force value of the air intake duct of this evaporator or this compressor.
11. the control method of flooded evaporator refrigerant liquid level as claimed in claim 2 is characterized in that, further has the step whether a compressor turns round between this step B and this step C1, if this compressor does not turn round, then finishes; If this compressor operation then carries out this step C1.
12. the control method of flooded evaporator refrigerant liquid level as claimed in claim 2; It is characterized in that; Whether between this step C4 and this step D1, further have a compressor turns round and is greater than or less than the step that equals a special time; If this compressor operation is smaller or equal to this special time, the aperture of this electronic expansion valve is 50～100%, then gets back to this step B; If this compressor operation greater than this special time, then carries out this step D1.
13. the control method of flooded evaporator refrigerant liquid level as claimed in claim 12 is characterized in that, this special time is 3～5 minutes.
14. the control method of flooded evaporator refrigerant liquid level as claimed in claim 2; It is characterized in that; In this step D1, this electronic expansion valve reduces 5% aperture one by one in a firm output cycle, and this electronic expansion valve maximum opening restriction equals the present aperture of this electronic expansion valve.
15. the control method of flooded evaporator refrigerant liquid level as claimed in claim 14 is characterized in that, in this step D1, this setting value is zero.
16. the control method of flooded evaporator refrigerant liquid level as claimed in claim 14 is characterized in that, in this step D1, closes this hydraulic pressure and contracts when protecting flag, this electronic expansion valve maximum opening is removed, and gets into this step D2.
17. the control method of flooded evaporator refrigerant liquid level as claimed in claim 2; It is characterized in that; In this step D2; In greater than the neutral band of this arithmetic mean temperature difference value the time, this controller calculates the expectation aperture and action step number of this electronic expansion valve, to adjust the aperture of this electronic expansion valve.
18. the control method of flooded evaporator refrigerant liquid level as claimed in claim 17 is characterized in that, this action step number on the occasion of the time then increase the aperture of this electronic expansion valve, and get back to this step B.
19. the control method of flooded evaporator refrigerant liquid level as claimed in claim 17 is characterized in that, this action step number then reduces the aperture of this electronic expansion valve when being negative value, and gets back to this step B.
20. the control method of flooded evaporator refrigerant liquid level as claimed in claim 2 is characterized in that, this specified arithmetic mean temperature difference value, this specified frozen water are gone into the water outlet temperature approach, this arithmetic mean temperature difference modified value is set in this controller.
21. the control method of flooded evaporator refrigerant liquid level as claimed in claim 2; It is characterized in that; In this steps A and this step B, further have one and revise the method that this specified frozen water is gone into the water outlet temperature approach, the method that this specified frozen water of this correction is gone into out water temperature difference has following steps:
One, the frozen water of setting the rated full load operating condition is gone into out water temperature difference: set a specified frozen water and go into the water outlet temperature approach, this specified frozen water is gone into the specified frozen water that the water outlet temperature approach equals in this steps A and is gone into the water outlet temperature approach;
Two, whether compressor turns round: if this compressor does not turn round, promptly finish; If this compressor operation then carries out next step;
Three, whether compressor reaches full carrier strip spare: if this compressor operation does not reach this full carrier strip spare, then do not revise, then to this step 2; If this compressor operation reaches full carrier strip spare, then carry out next step;
Four, calculate compressor and go into the water outlet temperature approach in the frozen water of full carrier strip spare running: this controller is gone into coolant-temperature gage and this frozen water leaving water temperature according to this frozen water, draws the frozen water of this compressor when full carrier strip spare and goes into the water outlet temperature approach;
Five, automatically whether judgement is readjusted specified frozen water and is gone into out the water temperature difference setting value: go into out water temperature difference and this frozen water is gone into out water temperature difference according to this specified frozen water; And draw an error amount; If the absolute value of this error amount during smaller or equal to a setting value, then is failure to actuate, and to this step 2; If this absolute value greater than this setting value, then carries out next step;
Six, judge whether the number of times recur is equal to or less than a fixed number of times: if this absolute value equals this fixed number of times greater than the frequency of this setting value, then this frozen water is gone into the water outlet temperature approach and is replaced this specified frozen water and go into out water temperature difference, and gets back to this step 2; If this absolute value, is not then revised less than this fixed number of times greater than the frequency of this setting value, and to this step 2.
22. the control method of flooded evaporator refrigerant liquid level as claimed in claim 21 is characterized in that, this setting value is 5%, and this fixed number of times is five～ten times.
23. the control method of flooded evaporator refrigerant liquid level as claimed in claim 22 is characterized in that, this frozen water is gone into the CWRT that abbreviates as of coolant-temperature gage, this frozen water leaving water temperature abbreviate CWLT as, this frozen water is gone into the abbreviation Δ T of water outlet temperature approach
Real, the computing formula that this frozen water is gone into the water outlet temperature approach is: Δ T
Real=CWRT-CWLT; What this specified frozen water was gone into the water outlet temperature approach abbreviates Δ T as
Setpoint, the computing formula of this error amount is: ABS (Δ T
Real-Δ T
Setpoint)/Δ T
Setpoint>=5%.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW099138556 | 2010-11-09 | ||
| TW099138556A TWI401402B (en) | 2010-11-09 | 2010-11-09 | Refrigerant liquid level control method for flooded evaporator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102467135A true CN102467135A (en) | 2012-05-23 |
| CN102467135B CN102467135B (en) | 2013-06-05 |
Family
ID=46070867
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010105769430A Active CN102467135B (en) | 2010-11-09 | 2010-12-02 | Refrigerant liquid level control method for flooded evaporator |
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| Country | Link |
|---|---|
| CN (1) | CN102467135B (en) |
| TW (1) | TWI401402B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103776186A (en) * | 2012-10-23 | 2014-05-07 | 荏原冷热系统株式会社 | Turbine refrigerator |
| CN108759178A (en) * | 2018-05-22 | 2018-11-06 | 特灵空调系统(中国)有限公司 | The liquid level controlling method and cooling cycle system of flooded evaporator |
| US11365921B2 (en) | 2015-09-18 | 2022-06-21 | Carrier Corporation | System and method of freeze protection for a chiller |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI472708B (en) * | 2012-08-13 | 2015-02-11 | Univ Nat Taipei Technology | Chiller refrigerant cycle system with fluid refrigerant control |
| EP2937657B1 (en) * | 2014-04-25 | 2019-11-27 | Franke Technology and Trademark Ltd | Heat exchanger |
| US10403946B2 (en) * | 2016-06-14 | 2019-09-03 | Ford Global Technologies, Llc | Battery chiller control with electronic expansion device |
| CN111594280B (en) * | 2020-06-23 | 2023-09-19 | 南京天加能源科技有限公司 | Dual-turbine gas suspension ORC power generation system and control method |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0710808A1 (en) * | 1994-11-01 | 1996-05-08 | Nippondenso Co., Ltd. | Refrigerant evaporator |
| JPH09170832A (en) * | 1995-11-14 | 1997-06-30 | Lg Electronics Inc | Refrigerating cycle device having two evaporation temperature |
| CN1502923A (en) * | 2002-11-22 | 2004-06-09 | Lg������ʽ���� | Air conditioner and method for controlling electronic expansion valve of same |
| CN200943982Y (en) * | 2006-08-11 | 2007-09-05 | 无锡同方人工环境有限公司 | Constant speed hot pump unit with controlled throttle style |
| CN101078569A (en) * | 2006-05-23 | 2007-11-28 | 东元电机股份有限公司 | Full liquid type ice water machine |
| CN101240962A (en) * | 2008-01-18 | 2008-08-13 | 西安交通大学 | Carbon dioxide heat pump control method based on pressure-temperature |
| CN101498534A (en) * | 2008-12-08 | 2009-08-05 | 天津大学 | Multi-target intelligent control method for electronic expansion valve of refrigeration air conditioner heat pump system |
| US20100205988A1 (en) * | 2009-02-18 | 2010-08-19 | Chao Jiang | Condensing Unit Having Fluid Injection |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI309706B (en) * | 2006-05-11 | 2009-05-11 | Teco Elec & Machinery Co Ltd | Flooded chiller and method for controlling refrigerant level thereof |
| CN2896239Y (en) * | 2006-05-15 | 2007-05-02 | 浙江理工大学 | Full-liquid type vaporizor liquid-level detector |
-
2010
- 2010-11-09 TW TW099138556A patent/TWI401402B/en active
- 2010-12-02 CN CN2010105769430A patent/CN102467135B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0710808A1 (en) * | 1994-11-01 | 1996-05-08 | Nippondenso Co., Ltd. | Refrigerant evaporator |
| JPH09170832A (en) * | 1995-11-14 | 1997-06-30 | Lg Electronics Inc | Refrigerating cycle device having two evaporation temperature |
| CN1502923A (en) * | 2002-11-22 | 2004-06-09 | Lg������ʽ���� | Air conditioner and method for controlling electronic expansion valve of same |
| CN101078569A (en) * | 2006-05-23 | 2007-11-28 | 东元电机股份有限公司 | Full liquid type ice water machine |
| CN200943982Y (en) * | 2006-08-11 | 2007-09-05 | 无锡同方人工环境有限公司 | Constant speed hot pump unit with controlled throttle style |
| CN101240962A (en) * | 2008-01-18 | 2008-08-13 | 西安交通大学 | Carbon dioxide heat pump control method based on pressure-temperature |
| CN101498534A (en) * | 2008-12-08 | 2009-08-05 | 天津大学 | Multi-target intelligent control method for electronic expansion valve of refrigeration air conditioner heat pump system |
| US20100205988A1 (en) * | 2009-02-18 | 2010-08-19 | Chao Jiang | Condensing Unit Having Fluid Injection |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103776186A (en) * | 2012-10-23 | 2014-05-07 | 荏原冷热系统株式会社 | Turbine refrigerator |
| US11365921B2 (en) | 2015-09-18 | 2022-06-21 | Carrier Corporation | System and method of freeze protection for a chiller |
| CN108759178A (en) * | 2018-05-22 | 2018-11-06 | 特灵空调系统(中国)有限公司 | The liquid level controlling method and cooling cycle system of flooded evaporator |
Also Published As
| Publication number | Publication date |
|---|---|
| TWI401402B (en) | 2013-07-11 |
| TW201219731A (en) | 2012-05-16 |
| CN102467135B (en) | 2013-06-05 |
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