CN102467135B - Refrigerant liquid level control method for flooded evaporator - Google Patents
Refrigerant liquid level control method for flooded evaporator Download PDFInfo
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- CN102467135B CN102467135B CN2010105769430A CN201010576943A CN102467135B CN 102467135 B CN102467135 B CN 102467135B CN 2010105769430 A CN2010105769430 A CN 2010105769430A CN 201010576943 A CN201010576943 A CN 201010576943A CN 102467135 B CN102467135 B CN 102467135B
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- 239000003507 refrigerant Substances 0.000 title claims abstract description 128
- 238000000034 method Methods 0.000 title claims abstract description 41
- 239000007788 liquid Substances 0.000 title 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 163
- 230000009183 running Effects 0.000 claims description 17
- 230000007935 neutral effect Effects 0.000 claims description 11
- 230000006835 compression Effects 0.000 claims description 10
- 238000007906 compression Methods 0.000 claims description 10
- 230000009471 action Effects 0.000 claims description 9
- 238000013459 approach Methods 0.000 claims description 6
- 238000005259 measurement 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
- 230000008859 change Effects 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
- 239000002826 coolant Substances 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
- 238000012937 correction 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
- 230000035800 maturation Effects 0.000 description 1
- 238000002715 modification method Methods 0.000 description 1
- 230000001737 promoting effect Effects 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 method of controlling refrigerant level of flooded evaporator, it provides the actual frozen water of a kind of measurement to enter temperature difference of outlet water value, 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 adjust the aperture of electronic expansion valve according to this error amount, to control the refrigerant liquid level of evaporator, and can effectively bring into play the heat exchange area of evaporator, and can promote evaporating temperature.
Background technology
In recent years the technology of refrigerating and air conditioning has leveled off to maturation, right key concept of 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 the full-liquid type coolant system, this full-liquid type coolant system has a compressor, a condenser, an electronic expansion valve and a flooded evaporator, compressor has an inlet end and an endpiece, endpiece connects condenser with a pipeline, condenser is with a pipeline connecting electronic formula expansion valve, electronic expansion valve is to connect flooded evaporator with a pipeline, flooded evaporator is to connect compressor with a pipeline, separately is provided with a liquid level sensor in flooded evaporator.
In flooded evaporator, the liquid level of refrigerant is under optimum condition, it just covers and is arranged in the copper pipe that flooded evaporator is gone up row most, so that refrigerant carries out heat interchange with the liquid that flows in copper pipe, this liquid can be water, oil or bittern etc., in order effectively to control the refrigerant liquid level, in prior art to adopt liquid level sensor, the pressure of detecting condenser and three kinds of common modes of progressive temperature.
The mode of the first liquid level sensor, it coordinates liquid level sensor with electronic expansion valve, be used as controlling the method for refrigerant liquid level, under fully loaded standard conditions, i.e. compressor 100% running, liquid level sensor can be controlled the refrigerant liquid level very accurately, but in virtual condition, compressor might only have fractional load, and refrigerant liquid level and actual liquid level because liquid level sensor sets both have great difference; Moreover the evaporation of refrigerant boiling also can increase whole variable, and makes the refrigerant non-optimal liquid level place of being in, 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.
the mode of the second utilization detecting condenser pressure, it converts the pressure of detecting to temperature, add a temperature gap, with the temperature that spues as a refrigerant, and then control refrigerant liquid level, but the height of refrigerant liquid level is subject to the impact of evaporator refrigerant temperature, and the temperature variation that spues of refrigerant can be said very little, 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 as the external world enters in evaporator, cause evaporating temperature and the illusion of the excess Temperature that spues, increase and make the difficulty of controlling, moreover, the pressure of detecting condenser also can't be applied to the demand of the optimal liquid level under fractional load or low condensing pressure condition.
The third adopts the control mode of progressive temperature, it utilizes the temperature gap that keeps frozen water leaving water temperature and evaporator refrigerant temperature to fix, reach the purpose that the refrigerant liquid level is controlled, 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 better refrigerant liquid level, so existing refrigerant liquid level controlling method still is improved the space.
Summary of the invention
because above-mentioned shortcoming, the object of the present invention is to provide a kind of method of controlling refrigerant level of flooded evaporator, the frozen water that its utilization sets enters temperature difference of outlet water, measured actual frozen water enters the temperature difference of outlet water value, the refrigerant temperature that spues, refrigerant evaporation force value and refrigerant condensing pressure value, to adjust the aperture of 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 turn round under the evaporator refrigerant temperature of the best, promote the running efficiency under frozen water machine part loading condition, and also have advantages of with low cost high with liquid level control precision.
To achieve the above object, technological means of the present invention is to provide a kind of method of controlling refrigerant level of flooded evaporator, 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 enter 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: according to the data of this steps A and B gained, and draw error amount.
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 steps A as above, temperature approach and modified value are that specified arithmetic mean temperature difference, a specified frozen water of an evaporator enters temperature difference of outlet water value, an arithmetic mean temperature difference modified value, the neutral band of 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 enter temperature difference of outlet water value, arithmetic mean temperature difference modified value and the temperature modified value that spues is set in a controller; And electronic expansion valve can be 50～100% in the setting value that the initial opening of a compressor start running sets.
Step B as above, it measures respectively frozen water with a plurality of temperature sensors and enters coolant-temperature gage, frozen water leaving water temperature and the refrigerant temperature that spues, and separately measures respectively the refrigerant condensing pressure value of the discharge pipe of the refrigerant evaporation force value of air intake duct of evaporator or compressor and condenser or compressor with a plurality of pressure transducers.Temperature sensor and pressure transducer enter 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 measures and send controller to.
Step C as above, 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 the temperature approach, this arithmetic mean temperature difference modified value and this specified arithmetic mean temperature difference that enter 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: according to the refrigerant evaporation force value, and draw an evaporator refrigerant temperature.
C3, the actual arithmetic mean temperature difference of calculating: enter 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: according to refrigerant temperature and the expectation refrigerant temperature that spues that spues, and draw the actual and expectation temperature error values 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 referred to as RSEP, the refrigerant condensing pressure value referred to as RSCP, the temperature that spues modified value referred to as C
SHDT, the expectation spue temperature referred to as SHDT
exp, the spue computing formula of temperature of expectation 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 enter coolant-temperature gage referred to as CWRT, the frozen water leaving water temperature referred to as CWLT, specified frozen water enters temperature difference of outlet water referred to as Δ T, the arithmetic mean temperature difference modified value referred to as C
Δ tm, specified arithmetic mean temperature difference referred to as Δ t
m, expectation arithmetic mean temperature difference value referred to as Δ t
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 referred to as RSET, 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 expectation spues temperature error values referred to as Err
Δ SHDT, the spue computing formula of temperature error values of actual and expectation is: Err
Δ SHDT=SHDT-SHDT
expReality and expectation arithmetic mean temperature difference error amount are referred to as Err
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)
Step D as above, it further has:
D1, judge this reality and expectation spue temperature error values whether less than or equal to or greater than a setting value: setting value is zero, when temperature error values is less than or equal to setting value if actual and expectation spues, open a hydraulic compression protection flag, reduce the aperture of this electronic expansion valve; When temperature error values is greater than setting value if actual and expectation spues, closes this hydraulic compression protection flag, and enter next step.
D2, judge whether this reality and expectation arithmetic mean temperature difference error amount are greater than or less than and equal the neutral band of arithmetic mean temperature difference value: if less than or equal to the neutral band of arithmetic mean temperature difference value, electronic expansion valve is kept existing aperture, and gets back to step B; If greater than the neutral band of arithmetic mean temperature difference value, adjust the aperture of electronic expansion valve, and get back to step B.
As mentioned above, further have the step whether a compressor turns round between step B and step C1, if compressor does not turn round, finish; If compressor operation carries out step C1.
As mentioned above, whether further have a compressor between step C4 and step D1 and turn round and be greater than or less than the step that equals a special time, special time is 3～5 minutes, if compressor operation is less than or equal to special time, the aperture of electronic expansion valve is 50～100%, gets back to step B; If compressor operation greater than special time, carries out step D1.
Step D1 as above, electronic expansion valve successively reduces 5% aperture in a firm output cycle, and the restriction of electronic expansion valve maximum opening equals the present aperture of electronic expansion valve.
When closing this hydraulic compression protection flag, the electronic expansion valve maximum opening is removed, and enters this step D2.
Step D2 as above, 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, to adjust the aperture of electronic expansion valve.
The action step number on the occasion of the time increase the aperture of electronic expansion valve, and get back to this step B; The action step number reduces the aperture of electronic expansion valve when being negative value, and gets back to this step B.
Further have one in steps A as above and step B and revise the method that this specified frozen water enters the temperature difference of outlet water value, its step includes:
One, the frozen water of setting rated full load enters the temperature difference of outlet water value: set a specified frozen water and enter the temperature difference of outlet water value, specified frozen water enters the specified frozen water that the temperature difference of outlet water value equals in steps A and enters the temperature difference of outlet water value.
Two, whether compressor turns round: if compressor does not turn round, namely finish; If compressor operation carries out next step.
Three, whether compressor reaches full carrier strip spare: if compressor operation does not reach full carrier strip spare, do not revise, to step 2; If compressor operation reaches full carrier strip spare, carry out next step.
Four, calculate compressor and enter the temperature difference of outlet water value in the frozen water of full carrier strip spare running: controller enters 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 enters the temperature difference of outlet water value;
Five, determine whether that automatically readjusting specified frozen water enters the temperature difference of outlet water setting value: the specified frozen water of foundation enters temperature difference of outlet water and frozen water enters the temperature difference of outlet water value, and draw an error amount, if the absolute value of error amount during less than or equal to a setting value, is failure to actuate, to step 2, setting value is 5%; If absolute value greater than this setting value, 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, frozen water enters the specified frozen water of temperature difference of outlet water value replacement and enters temperature difference of outlet water, and gets back to step 2; If absolute value, is not revised less than this fixed number of times greater than the frequency of setting value, and to step 2.
Frozen water enters the abbreviation Δ T of temperature difference of outlet water value
Real, the computing formula that frozen water enters the temperature difference of outlet water value is: Δ T
Real=CWRT-CWLT; Specified frozen water enter the temperature difference of outlet water value referred to as Δ T
Setpoint, the computing formula of error amount is: │ (Δ T
Real– Δ T
Setpoint) │/Δ T
Setpoint＞=5%.
beneficial functional of the present invention is: comprehensive above-mentioned method, its be mainly according to actual and expectation spue temperature error values and actual with expect the arithmetic mean temperature difference error amount, to adjust the aperture of 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 evaporator refrigerant temperature running of the best, therefore it is lower that the present invention has expense, it is good that liquid level is resolved precision, during the controllable portion loading condition, refrigerant is in the advantage of optimal liquid level.
Describe the present invention below in conjunction with the drawings and specific embodiments, but not as a limitation of the invention.
Description of drawings
Fig. 1 is the schematic diagram of the frozen water machine of application method of controlling refrigerant level of flooded evaporator of the present invention;
Fig. 2 A and Fig. 2 B are the schematic flow sheet of method of controlling refrigerant level of flooded evaporator of the present invention;
Fig. 3 is the schematic flow sheet that the frozen water temperature difference of outlet water value 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 the drawings and specific embodiments, technical solution of the present invention being described in detail, further understanding purpose of the present invention, scheme and effect, but is not the restriction as 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 method of controlling refrigerant level of flooded evaporator, and its step includes:
A, setting pacing items 20: set an evaporator 11 in a controller 10, the specified arithmetic mean temperature difference value when the rated full load operating condition (hereinafter to be referred as, Δ t
m) enter temperature difference of outlet water value (hereinafter to be referred as, Δ T) with a specified frozen water, separately set an arithmetic mean temperature difference modified value (hereinafter to be referred as, C in controller 10
Δ tm), a neutral band of 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 enters temperature difference of outlet water and can change according to the frozen water flow, and this specified frozen water enters the change setting means of temperature difference of outlet water, please see below.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 enter coolant-temperature gage (hereinafter to be referred as, CWRT), separately 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, electronic expansion valve 14 apertures are 0%220, and finish 221; If compressor 12 runnings 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 at foundation 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 less than or equal to a special time, the aperture of electronic expansion valve 14 is 50～100%270, get back to above-mentioned step B271, whole step again, this special time is 3～5 minutes; If when compressor 12 turns round greater than this special time, carry out next step.
I, judgement Err
Δ SHDTWhether less than or equal to or greater than a setting value 28: controller 10 is for 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 SHDTLess than or equal to zero the time, open hydraulic compression protection flag 280, electronic expansion valve 14 successively reduces 5% aperture 281 in a firm output cycle, to carry out the protection flow process of a hydraulic compression, until SHDT is greater than SHDT
exp, i.e. electronic expansion valve 14 maximum opening restrictions equal the present aperture 282 of electronic expansion valve 14, and get back to step B283;
If, Err
Δ SHDTGreater than zero the time, close hydraulic compression protection flag 284, electronic expansion valve maximum opening restriction cancellation 285, and enter next step.
J, judgement Err
Δ tmAbsolute value whether less than or equal to or greater than dead band29: if during less than or equal to dead band, electronic expansion valve 14 is kept existing aperture 290, and gets back to step B283;
If during greater than dead band, controller 10 calculates the expectation aperture and action step number 291 of electronic expansion valve 14, adjusting the aperture of electronic expansion valve 14, if the action step number on the occasion of the time increase the aperture 292 of electronic expansion valve 14, and get back to step B283;
If 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 to repeat whole step, situation about repeatedly occuring with the protection flow process of avoiding hydraulic compression.
Though can be by above-mentioned design temperature, measure actual pressure and be converted to temperature and measure actual temperature after, controller 10 is according to aforesaid data and modified value, determine whether will adjust again the aperture of electronic expansion valve 14, with the refrigerant liquid level of the running efficiency of effective lifting frozen water machine under the fractional load condition with the best.But the frozen water fluctuations in discharge can change frozen water enters the temperature difference of outlet water value, it can cause the Δ T that sets at first may have great error amount, and can cause the aperture adjustment of electronic expansion valve 14 improper, therefore must entering out temperature approach according to actual frozen water, Δ T automatically revises, this modification method is to be applied in above-mentioned steps A and B, and the step of this revised law is as follows:
One, the frozen water of setting the rated full load operating condition enters temperature difference of outlet water value 30: as above-mentioned steps A, setting one specified frozen water enters the temperature difference of outlet water value (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, namely 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 namely 100%, do not revise 320, and to step 2 351; If compressor 12 runnings reach full carrier strip spare, carry out next step.
Four, calculate compressor 12 and enter temperature difference of outlet water value 33 in the frozen water of full carrier strip spare running: controller 10 is according to CWRT and CWLT, enters the temperature difference of outlet water value (hereinafter to be referred as, Δ T and draw the frozen water of compressor 12 when full carrier strip spare turns round
Real), computing formula is: Δ T
Real=CWRT-CWLT.
Five, determine whether that automatically readjusting specified frozen water enters temperature difference of outlet water 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 during less than or equal to a setting value, this setting value can be 5%, does not revise 320, and to step 2 351, computing formula is: │ (Δ T
Real-Δ T
Setpoint) │/Δ T
Setpoint＞=5%; If this absolute value greater than this setting value, carries out next step.
Six, whether the number of times that recurs of judgement 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 greater than this setting value, but frequency does not revise 320 less than this fixed number of times, and to step 2 351; If frequency equals this fixed number of times, Δ T
Setpoint Equal Δ T
Real350, i.e. Δ T
RealBe replaced in the Δ T that step 1 sets, and return step 2 351, to repeat whole step.
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 tmAnd whether decision will adjust the aperture of electronic expansion valve 14, promoting 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 evaporator 11 in the evaporator refrigerant temperature running of the best.
Certainly; the present invention also can have other various embodiments; in the situation that do not deviate from spirit of the present invention and essence thereof; those of ordinary skill in the art work as can make according to the present invention various corresponding changes and distortion, but these corresponding changes and distortion all should belong to the protection domain of the appended claim of the present invention.
Claims (22)
1. the control method of a refrigerant level of flooded evaporator, 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 enter 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: according to the data of this steps A and B gained, and draw error amount;
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;
Wherein, the 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 enters temperature difference of outlet water value, an arithmetic mean temperature difference modified value, the neutral band of 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 a compressor start running sets;
In this step B, its frozen water that measures an evaporator enters coolant-temperature gage and frozen water leaving water temperature; And the refrigerant that measures the compressor temperature value that spues;
In 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 enter coolant-temperature gage, this frozen water leaving water temperature, this specified frozen water according to this frozen water and enter temperature difference of outlet water value, 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: according to this refrigerant evaporation force value, and draw an evaporator refrigerant temperature; C3, the actual arithmetic mean temperature difference value of calculating: enter 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;
In this step D, it further has: D1, judge this reality and expectation spue temperature error values whether less than or equal to or greater than a setting value: if should reality and expectation spue temperature error values during less than or equal to this setting value, open a hydraulic compression protection flag, reduce the aperture of this electronic expansion valve; If should reality and expectation spue temperature error values during greater than this setting value, close this hydraulic compression protection flag, and enter next step; D2, judge whether this reality and expectation arithmetic mean temperature difference error amount are greater than or less than and equal the neutral band of this arithmetic mean temperature difference value: if less than or equal to the neutral band of this arithmetic mean temperature difference value, this electronic expansion valve is kept existing aperture, and gets back to this step B; If greater than the neutral band of this arithmetic mean temperature difference value, adjust the aperture of this electronic expansion valve, and get back to this step B.
2. the control method of refrigerant level of flooded evaporator as claimed in claim 1, is characterized in that, in this step C1, this refrigerant evaporation force value referred to as RSEP, this refrigerant condensing pressure value referred to as RSCP, this temperature modified value that spues referred to as C
SHDT, this expectation spue temperature referred to as SHDT
exp, the spue computing formula of temperature of this expectation is: SHDT
exp=a+b * (RSCP)+c * (RSCP)
2+ d * (RSEP)+C
SHDT, and a, b, c, d are constant.
3. the control method of refrigerant level of flooded evaporator as claimed in claim 2, is characterized in that, in this step C1, this frozen water enter coolant-temperature gage referred to as CWRT, this frozen water leaving water temperature referred to as CWLT, this arithmetic mean temperature difference modified value referred to as C
Δ tm, this specified arithmetic mean temperature difference referred to as Δ t
m, this expectation arithmetic mean temperature difference value referred to as Δ t
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, wherein, specified frozen water enters temperature difference of outlet water referred to as Δ T.
4. the control method of refrigerant level of flooded evaporator as claimed in claim 3, it is characterized in that, in this step C2, this evaporator refrigerant temperature referred to as RSET, the computing formula of this evaporator refrigerant temperature is: RSET=a1+b1 * (RSEP)+c1 * (RSEP)
0.5, wherein a1, b1, c1 are constant.
5. the control method of refrigerant level of flooded evaporator as claimed in claim 4, 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.
6. the control method of refrigerant level of flooded evaporator as claimed in claim 5, is characterized in that, in this step C4, this reality and expectation spue temperature error values referred to as Err
Δ SHDT, the spue computing formula of temperature error values of this reality and expectation is: Err
Δ SHDT=SHDT-SHDT
expThis reality and expectation arithmetic mean temperature difference error amount are referred to as Err
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)
7. the control method of refrigerant level of flooded evaporator as claimed in claim 6, 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.
8. the control method of refrigerant level of flooded evaporator as claimed in claim 1, it is characterized in that, in this step B, it measures respectively this frozen water with a plurality of temperature sensors and enters coolant-temperature gage, this frozen water leaving water temperature and this refrigerant temperature that spues, separately measure respectively this refrigerant evaporation force value and this refrigerant condensing pressure value with a plurality of pressure transducers, this temperature sensor and this pressure transducer enter 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 measures and send a controller to.
9. the control method of refrigerant level of flooded evaporator as claimed in claim 8, 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 the refrigerant evaporation force value of the air intake duct of this pressure transducer system's this evaporator of measurement or this compressor.
10. the control method of refrigerant level of flooded evaporator as claimed in claim 1, 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, finishes; If this compressor operation carries out this step C1.
11. the control method of refrigerant level of flooded evaporator as claimed in claim 1, it is characterized in that, whether further have a compressor between this step C4 and this step D1 turns round and is greater than or less than the step that equals a special time, if this compressor operation is less than or equal to this special time, the aperture of this electronic expansion valve is 50～100%, gets back to this step B; If this compressor operation greater than this special time, carries out this step D1.
12. the control method of refrigerant level of flooded evaporator as claimed in claim 11 is characterized in that, this special time is 3～5 minutes.
13. the control method of refrigerant level of flooded evaporator as claimed in claim 1, it is characterized in that, in this step D1, this electronic expansion valve successively reduces 5% aperture in a firm output cycle, and this electronic expansion valve maximum opening restriction equals the present aperture of this electronic expansion valve.
14. the control method of refrigerant level of flooded evaporator as claimed in claim 13 is characterized in that, in this step D1, this setting value is zero.
15. the control method of refrigerant level of flooded evaporator as claimed in claim 13 is characterized in that, in this step D1, when closing this hydraulic compression protection flag, this electronic expansion valve maximum opening is removed, and enters this step D2.
16. the control method of refrigerant level of flooded evaporator as claimed in claim 1, 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.
17. the control method of refrigerant level of flooded evaporator as claimed in claim 16 is characterized in that, this action step number on the occasion of the time increase the aperture of this electronic expansion valve, and get back to this step B.
18. the control method of refrigerant level of flooded evaporator as claimed in claim 16 is characterized in that, this action step number reduces the aperture of this electronic expansion valve when being negative value, and gets back to this step B.
19. the control method of refrigerant level of flooded evaporator as claimed in claim 1 is characterized in that, this specified arithmetic mean temperature difference value, this specified frozen water enter the temperature difference of outlet water value, this arithmetic mean temperature difference modified value is set in this controller.
20. the control method of refrigerant level of flooded evaporator as claimed in claim 1, it is characterized in that, further have one and revise the method that this specified frozen water enters the temperature difference of outlet water value in this steps A and this step B, this is revised the method that this specified frozen water enters temperature difference of outlet water and has following steps:
One, the frozen water of setting the rated full load operating condition enters temperature difference of outlet water: set a specified frozen water and enter the temperature difference of outlet water value, this specified frozen water enters the specified frozen water that the temperature difference of outlet water value equals in this steps A and enters the temperature difference of outlet water value;
Two, whether compressor turns round: if this compressor does not turn round, namely finish; If this compressor operation carries out next step;
Three, whether compressor reaches full carrier strip spare: if this compressor operation does not reach this full carrier strip spare, do not revise, to this step 2; If this compressor operation reaches full carrier strip spare, carry out next step;
Four, calculate compressor and enter the temperature difference of outlet water value in the frozen water of full carrier strip spare running: this controller enters 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 enters the temperature difference of outlet water value;
Five, determine whether that automatically readjusting specified frozen water enters the temperature difference of outlet water setting value: this specified frozen water of foundation enters temperature difference of outlet water and this frozen water enters temperature difference of outlet water, and draw an error amount, if the absolute value of this error amount during less than or equal to a setting value, is failure to actuate, and to this step 2; If this absolute value greater than this setting value, carries out next step;
Six, whether the number of times that recurs of judgement 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, this frozen water enters the temperature difference of outlet water value and replaces this specified frozen water and enter temperature difference of outlet water, and gets back to this step 2; If this absolute value, is not revised less than this fixed number of times greater than the frequency of this setting value, and to this step 2.
21. the control method of refrigerant level of flooded evaporator as claimed in claim 20 is characterized in that, this setting value is 5%, and this fixed number of times is five～ten times.
22. the control method of refrigerant level of flooded evaporator as claimed in claim 21 is characterized in that, this frozen water enter coolant-temperature gage referred to as CWRT, this frozen water leaving water temperature referred to as CWLT, this frozen water enters the abbreviation Δ T of temperature difference of outlet water value
Real, the computing formula that this frozen water enters the temperature difference of outlet water value is: Δ T
Real=CWRT-CWLT; This specified frozen water enter the temperature difference of outlet water value referred to as Δ T
Setpoint, the computing formula of this error amount is: │ (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 |
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| Publication Number | Publication Date |
|---|---|
| CN102467135A CN102467135A (en) | 2012-05-23 |
| CN102467135B true CN102467135B (en) | 2013-06-05 |
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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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|---|---|
| CN (1) | CN102467135B (en) |
| TW (1) | TWI401402B (en) |
Families Citing this family (7)
| 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 |
| JP2014085048A (en) * | 2012-10-23 | 2014-05-12 | Ebara Refrigeration Equipment & Systems Co Ltd | Turbo refrigerator |
| EP2937657B1 (en) * | 2014-04-25 | 2019-11-27 | Franke Technology and Trademark Ltd | Heat exchanger |
| WO2017049258A1 (en) | 2015-09-18 | 2017-03-23 | Carrier Corporation | System and method of freeze protection for a chiller |
| US10403946B2 (en) * | 2016-06-14 | 2019-09-03 | Ford Global Technologies, Llc | Battery chiller control with electronic expansion device |
| CN108759178B (en) * | 2018-05-22 | 2020-11-06 | 特灵空调系统(中国)有限公司 | Liquid level control method of flooded evaporator and refrigeration cycle system |
| 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 (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0710808A1 (en) * | 1994-11-01 | 1996-05-08 | Nippondenso Co., Ltd. | Refrigerant evaporator |
| 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 |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100393776B1 (en) * | 1995-11-14 | 2003-10-11 | 엘지전자 주식회사 | Refrigerating cycle device having two evaporators |
| 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 |
| US8539785B2 (en) * | 2009-02-18 | 2013-09-24 | Emerson Climate Technologies, Inc. | Condensing unit having fluid injection |
-
2010
- 2010-11-09 TW TW099138556A patent/TWI401402B/en active
- 2010-12-02 CN CN2010105769430A patent/CN102467135B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0710808A1 (en) * | 1994-11-01 | 1996-05-08 | Nippondenso Co., Ltd. | Refrigerant evaporator |
| 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 |
Non-Patent Citations (1)
| Title |
|---|
| JP特开平9-170832A 1997.06.30 |
Also Published As
| Publication number | Publication date |
|---|---|
| TWI401402B (en) | 2013-07-11 |
| TW201219731A (en) | 2012-05-16 |
| CN102467135A (en) | 2012-05-23 |
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