CN111678280B - Frost control method based on fuzzy partition frosting map - Google Patents

Frost control method based on fuzzy partition frosting map Download PDF

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Publication number
CN111678280B
CN111678280B CN202010586598.2A CN202010586598A CN111678280B CN 111678280 B CN111678280 B CN 111678280B CN 202010586598 A CN202010586598 A CN 202010586598A CN 111678280 B CN111678280 B CN 111678280B
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frosting
area
defrosting
unit
frost
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CN111678280A (en
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王智伟
岳泓辰
魏鹏
王笙
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Xian University of Architecture and Technology
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D21/00—Defrosting; Preventing frosting; Removing condensed or defrost water
    • F25D21/002—Defroster control

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Abstract

The invention discloses a frost control method based on a fuzzy partition frosting map, which comprises the following steps: monitoring the outdoor environment temperature and the relative humidity, and judging whether the air state point is in a frosting area; judging the area of the air state point in the frosting area according to a fuzzy control rule formulated by a frosting map, and giving a frosting rate; controlling a heat pump unit to start defrosting according to the calculated frost layer thickness; judging whether defrosting is finished or not according to the actual defrosting time of the unit; the rate of frost and the evaporator coil surface set temperature are self-adjusted based on the effectiveness of the defrost. The invention combines the frosting map with fuzzy control, improves the accuracy of judging the frosting degree, avoids mistaken defrosting and prolongs the service life of the unit. The method is simple and practical and has high feasibility.

Description

Frost control method based on fuzzy partition frosting map
Technical Field
The invention relates to the field of air source heat pump frost control, in particular to a frost control method based on a fuzzy partition frosting map.
Background
The performance of the air source heat pump is greatly influenced by outdoor environment parameters, and when the surface temperature of the evaporator fin is lower than the dew point temperature of air and lower than the freezing point in winter, the surface of the evaporator can be frosted. The frosting can produce adverse effect to the operation of the air source heat pump unit, and the unit is stopped when the frosting is serious, so the defrosting must be carried out when the air source heat pump frosts. The existing typical defrosting control methods can be divided into two types, namely a time-based defrosting control method and a defrosting demand-based defrosting control method. The time-based control method is serious in 'false defrosting', and temperature or pressure parameters are usually increased and are used as defrosting criteria together with time. Temperature is not the only condition affecting frost formation and air pressure differentials are susceptible to evaporator surface conditions, both of which can lead to "false defrost". The existing control method based on the defrosting requirement generally needs to add hardware equipment on the original unit, so that the manufacturing cost is increased and the control method is not easy to realize.
Different meteorological characteristics lead to the frost degree difference, to the frost degree judge rationally can realize "defrosting as required". The frosting map is an effective tool for researching the frosting degree, and the frosting rate can be quickly obtained by acquiring the ambient temperature and humidity. The frosting map is divided into a frosting area, a dewing area and a non-frosting area, and the frosting area is divided into five areas by the frosting rate curve, namely a light frosting area, a medium frosting area, a heavy frosting area and a heavy frosting area. In practice, however, the partitions of the frosting area have uncertainty, five areas should not have definite boundaries, and the fuzzy control can solve the problem of boundary ambiguity well through fuzzification, defuzzification and self-adaptation. The fuzzy controller can be used for fuzzifying the map to fuzzify the partition boundary of the map, and meanwhile, the frosting map is used as expert experience to provide reference for formulating a fuzzy frost control rule. However, the frosting map has certain limitations in terms of the frosting distribution condition obtained by a certain unit under specific conditions, and needs to be adjusted by using a fuzzy control adaptive mechanism, so that the system continuously learns to reach a satisfactory working state, and the universality of the system is improved to adapt to different regions and units.
Disclosure of Invention
In order to solve the problem of 'false defrosting' in the conventional defrosting control, a frosting map is combined with fuzzy control, a frosting rate is given by judging the frosting degree by using a fuzzy controller, and the frosting thickness is calculated, so that a defrosting starting point is reasonably selected.
The purpose of the invention is realized by the following technical scheme.
A frost control method based on a fuzzy partition frosting map comprises the following steps:
step 1: for temperature and humidity T of outdoor environmentaMonitoring relative humidity RH, judging whether the air state point is in a frosting area U, if so, performing the next step, otherwise, monitoring again;
step 2: inputting the outdoor environment temperature and humidity frosting monitoring values into a fuzzy controller, judging which area of a frosting area the air state point is specifically located in according to a fuzzy control rule formulated by a frosting map, and simultaneously giving a frosting rate calculation value;
and step 3: calculating the thickness h of the frost layer under the heating working condition by using the frosting rate in the step 2iWhen the thickness of the frost layer exceeds 1/2 of the distance d between the fins of the evaporator coil of the outdoor heat pump unit, the heat pump unit starts defrosting, and the actual defrosting time tau of the unit is carried out2And evaporator coil surface temperature TwMonitoring, otherwise, returning to the step 2;
and 4, step 4: when the unit actually defrosts time tau2Not less than minimum heating time tau of unit1After 10%, entering judgment of ending defrosting, otherwise, monitoring actual defrosting time tau of the unit again2And evaporator coil surface temperature Tw；
And 5: surface temperature T of evaporator coilwGreater than or equal to the surface set temperature T of the evaporatorsAnd defrosting is finished; otherwise, the actual defrosting time tau of the unit is set2Judging; when the unit actually defrosts time tau2Reaching the minimum heating time tau of the unit 120%, defrosting is finished, otherwise, the actual defrosting time tau of the heat pump unit is monitored again2And evaporator coil surface temperature Tw；
Step 6: evaluating the defrosting starting point and the defrosting effect of the last time, and calculating the frosting rate v and the set temperature T of the surface of the evaporator coilsSelf-adjustment is performed.
Further, in the step 1, an air state point where the ambient temperature is lower than 6 ℃ and the relative humidity is higher than 50% is in the frosting area.
Further, in the step 1, the outdoor temperature T is adjustedaAnd the relative humidity RH is divided into a severe frosting area PB, a heavy frosting area PS, a moderate frosting area O, a light frosting area NB and a light frosting area NS from large to small, and the frosting area U is divided into the severe frosting area PB, the heavy frosting area PS, the moderate frosting area O, the light frosting area NB and the light frosting area NS from severe frosting to light frosting.
Further, in the step 2, according to fuzzy inference rules of the fuzzy controller, which area of the frosting area the air state point is in is judged in the blurred map, and an initial calculated value of the frosting rate v is given: the initial set value of the speed of each frosting area is the median of the interval, the frosting speed of the light frosting area NB is 0.1mm/h, the frosting speed of the light frosting area NS is 0.35mm/h, the frosting speed of the medium frosting area O is 0.7mm/h, the frosting speed of the heavy frosting area PS is 1.1mm/h, and the frosting speed of the heavy frosting area PB is 1.6 mm/h.
Further, in step 6, the method for evaluating the defrosting starting point and the defrosting effect is as follows:
instantaneous heating quantity q if the unit starts defrosting2Greater than the instantaneous heating capacity q in the frostless process 170% of the above, the calculated frosting rate v is reduced by 0.02 mm/h; instantaneous heating capacity q of the unit if defrosting is started2Instantaneous heating capacity q less than or equal to frostless process 170% of (A), the calculated frosting rate v increases by 0.02 mm/h.
Further, in the step 6, the calculated value of the frosting rate v and the set temperature T of the surface of the evaporator coilsSelf-adjustment is carried out by the following method:
after the heat supply is recovered, if the unit heats the quantity q3Instantaneous heating capacity q in frostless process or more1And 95 percent of the total temperature, the evaporation temperature set value is reduced by 0.1 ℃; if the unit heats the quantity q3Less than instantaneous heating capacity q in frostless process 195% of the evaporation temperature set point, the evaporation temperature set point is increased by 0.1 deg.c.
The invention has the beneficial effects that:
compared with the prior art, the frosting map is combined with the fuzzy control, the map is used as a basis for formulating the control rule, the control rule is more reasonable, meanwhile, the fuzzy control fuzzifies the subareas of different frosting areas of the map, the accuracy of judging the frosting degree is improved, and more accurate control is realized. The frosting degree is judged by the fuzzy controller, different frosting rate calculation values are given according to different frosting degrees, the frosting thickness is accurately calculated, the 'wrong defrosting' is avoided, and meanwhile, a self-adjusting mechanism is used for adjusting the rate value, so that the frosting map is adaptive to an application area. The 'wrong defrosting' is reduced, the energy consumption of the unit is reduced, and the service life is prolonged. The defrosting on demand is realized on the premise of not increasing the complexity of the system, hardware equipment is not required to be added, only a soft method is loaded in the original control method, and the method is simple, practical and high in feasibility.
Drawings
Fig. 1 is a flowchart of a defrost control method.
Detailed Description
The detailed description is given to the specific implementation of the regional frosting map-based frost control method provided by the invention, but the detailed description is not taken as a basis for limiting the invention.
Referring to the attached figure 1, the invention relates to a frost control method based on a fuzzy partition frosting map, which comprises the following steps:
step 1: for outdoor ambient temperature TaAnd monitoring the relative humidity RH, judging whether the air state point is in a frosting area U, if so, carrying out the next step, otherwise, monitoring again.
Wherein the outdoor ambient temperature T is measuredaAnd the relative humidity RH is divided into a severe frosting area PB, a heavy frosting area PS, a moderate frosting area O, a light frosting area NB and a light frosting area NS from large to small, and the frosting area U is divided into the severe frosting area PB, the heavy frosting area PS, the moderate frosting area O, the light frosting area NB and the light frosting area NS from severe frosting to light frosting. The air condition point in the frosting zone is such that both the ambient temperature is below 6 ℃ and the relative humidity is above 50%.
Step 2: the outdoor environment temperature and humidity frosting monitoring value is input into a fuzzy controller, a fuzzy control rule formulated by a frosting map is used for judging which area of a frosting area the air state point is specifically located in, and a frosting rate calculation value is given at the same time.
And judging which area of the frosting area the air state point is in the blurred map according to the fuzzy inference rule of the fuzzy controller. The fuzzy inference rule table is shown in table 1.
TABLE 1 fuzzy inference rule Table
Figure BDA0002554890170000051
The fuzzy inference rule is as follows:
(1) temperature TaIn the severe frosting zone PB:
the relative humidity RH is located in the severe frosting area PB, the heavy frosting area PS, and the moderate frosting area O, and then the frosting area U where the air state point is located is determined as the severe frosting area PB;
the relative humidity RH is located in the lighter frosting area NS, and then the frosting area U where the air state point is located is determined as a severe frosting area O;
the relative humidity RH is in the light frosting area NB, and then the frosting area U where the air state point is located is determined as the light frosting area NB.
(2) Temperature TaIn the severe frosting area PS:
the relative humidity RH is located in the severe frosting area PB, and then the frosting area U where the air state point is located is determined as the severe frosting area PB;
the relative humidity RH is located in the heavy frosting area PS, and then the frosting area U where the air state point is located is determined as the heavy frosting area PS;
the relative humidity RH is located in the moderate frosting area O, and then the frosting area U where the air state point is located is determined as the moderate frosting area O;
the relative humidity RH is located in the light frosting area NS, and then the frosting area U where the air state point is located is determined as the light frosting area NS;
the relative humidity RH is located in the light frosting area NB, and then the frosting area U where the air state point is located is judged as the light frosting area NB;
(3) temperature TaIn the moderate frosting zone O:
the relative humidity RH is located in the severe frosting area PB and the heavy frosting area PS, and then the frosting area U where the air state point is located is determined as the heavy frosting area PS;
the relative humidity RH is located in the moderate frosting area O, and then the frosting area U where the air state point is located is determined as the moderate frosting area O;
the relative humidity RH is located in the lighter frosting area NS and the light frosting area NB, and then the frosting area U where the air state point is located is determined as the light frosting area NB;
(4) temperature TaIn the less frosted zone NS:
the relative humidity RH is located in the severe frosting area PB and the heavy frosting area PS, and then the frosting area U where the air state point is located is determined as the moderate frosting area O;
the relative humidity RH is located in the moderate frosting area O, and then the frosting area U where the air state point is located is judged as a lighter frosting area NS;
the relative humidity RH is located in the lighter frosting area NS and the light frosting area NB, and then the frosting area U where the air state point is located is determined as the light frosting area NB;
(5) temperature TaIn the mild frosting zone NB:
the relative humidity RH is located in the severe frosting area PB and the heavy frosting area PS, and then the frosting area U where the air state point is located is determined as the light frosting area NS;
the relative humidity RH is located in the moderate frosting area O, the light frosting area NS, and the light frosting area NB, and then the frosting area U where the air condition point is located is determined as the light frosting area NB.
According to fuzzy inference rules of a fuzzy controller, judging which region of the frosting area the air state point is in the blurred map, and giving an initial calculated value of the frosting rate v: the initial set value of the speed of each frosting area is the median of the interval, the frosting speed of the light frosting area NB is 0.1mm/h, the frosting speed of the light frosting area NS is 0.35mm/h, the frosting speed of the medium frosting area O is 0.7mm/h, the frosting speed of the heavy frosting area PS is 1.1mm/h, and the frosting speed of the heavy frosting area PB is 1.6 mm/h.
And step 3: calculating the thickness h of the frost layer under the heating working condition by using the frosting rate in the step 2iWhen the thickness of the frost layer exceeds 1/2 of the distance d between the fins of the evaporator coil of the outdoor heat pump unit, the heat pump unit starts defrosting, and the actual defrosting time tau of the unit is carried out2And evaporator coil surface temperature TwAnd monitoring, otherwise, returning to the step 2.
Calculating the thickness of the frost layer under the heating working condition:
hi＝hi-1+vΔτ
wherein h isiIs the thickness of the frost layer in i time intervals, i is the number of times the time interval is recorded, hi-1The growth thickness of the frost layer in the first i-1 time intervals, Δ τ is the time interval monitored, and v is the frost formation rate.
And 4, step 4: when the unit actually defrosts time tau2Not less than minimum heating time tau of unit1After 10%, entering judgment of ending defrosting, otherwise, monitoring actual defrosting time tau of the unit again2And evaporator coil surface temperature Tw。
And 5: surface temperature T of evaporator coilwCoil gauge of evaporatorSet temperature T of surfacesDefrosting and frosting; otherwise, the actual defrosting time tau of the unit is set2Judging; when the unit actually defrosts time tau2Reaching the minimum heating time tau of the unit 120%, defrosting is finished, otherwise, the actual defrosting time tau of the heat pump unit is monitored again2And evaporator coil surface temperature Tw。
Step 6: evaluating the starting point and effect of last defrosting, calculating the frosting speed v and the set temperature T of the surface of the evaporator coilsSelf-adjustment is performed.
The method for evaluating the defrosting starting point and the defrosting effect comprises the following steps:
instantaneous heating quantity q if the unit starts defrosting2Greater than the instantaneous heating capacity q in the frostless process 170% of (a), the frosting rate calculated by v is reduced by 0.02 mm/h; instantaneous heating quantity q if the unit starts defrosting2Instantaneous heating capacity q less than or equal to frostless process 170% of (A), the frost-formation rate, calculated v, increases by 0.02 mm/h.
Calculated value of frost formation rate v and set temperature T of evaporator coil surfacesSelf-adjustment is carried out by the following method:
after heat supply is recovered, if the heat pump unit heats the heat quantity q3Instantaneous heating capacity q in frostless process or more1And 95 percent of the total temperature, the evaporation temperature set value is reduced by 0.1 ℃; if the heating capacity q of the heat pump unit3Less than instantaneous heating capacity q in frostless process 195% of the evaporation temperature set point, the evaporation temperature set point is increased by 0.1 deg.c.
The following different examples are given to further illustrate the invention.
Example 1
Step 1: monitoring outdoor ambient temperature TaAt 8 ℃ and a relative humidity RH of 45%, the ambient temperature T at this air pointaMore than 6 ℃ and relative humidity RH less than 50 percent, is positioned in a non-frosting area, does not carry out defrosting operation, and monitors outdoor environment temperature T againaAnd relative humidity RH, and the next judgment is made. The flow avoids "frostless defrosting" of the non-frosted areas.
Example 2
Step 1: monitoring roomOutside ambient temperature TaAt 3 ℃ and a relative humidity RH of 95%, the ambient temperature T at this air pointaAnd the relative humidity RH is higher than 50 percent and is lower than 6 ℃, and the next operation is carried out.
Step 2: will measure the outdoor ambient temperature TaAnd the relative humidity RH is input into the fuzzy controller to judge which frosting area the air state point is in. Outdoor ambient temperature TaWhen the temperature is 3 ℃ and the relative humidity RH is 95% and the severe frosting area PB is located, the air state point is located in the severe frosting area PB, and the frosting rate v calculated value is 1.6 mm/h.
And step 3: calculating the thickness of the frost layer by using the frosting rate v in the step 2 as 1.6mm/h, wherein the last defrosting effect is good and no frost layer is accumulated, and h is0The time interval delta tau monitored by the heat pump unit is 60s and the accumulated growth thickness h of the frost layer is 0mm10.0267 mm. The fin spacing of the outdoor evaporator of the heat pump unit is 1.5mm, the half 0.5d of the fin spacing is 0.75mm, and the cumulative growth thickness h of the frost layer1<0.75mm, return to step 2.
And 4, step 4: step 2 and step 3 are cycled for 28 times, and the frost layer accumulated growth thickness h is monitored for the 29 th time290.77mm and more than one half of the fin spacing of the outdoor evaporator by 0.75mm, starting defrosting operation, and recording the instantaneous heating quantity q when the unit starts defrosting2It was 1.7 kW.
And 5: monitoring actual defrosting time tau of unit2Is 13min, the surface temperature T of the coilwThe heating quantity q is 18 ℃ and the time group of defrosting is finished3Is 2 kW;
step 6: actual defrosting time tau of unit2Is 13min, minimum heating time tau110% of (b) is 6min, tau2>10％τ1And entering judgment of ending defrosting.
And 7: surface temperature T of evaporator coilwIs 18 ℃ lower than the set temperature T of the surface of the evaporator coil s20 ℃, and the actual defrosting time tau of the unit2Minimum heating time tau of sum unit1The judgment was made at 20%.
And 8: actual defrosting time tau of unit2Is 13min, the minimum heating time tau of the unit 120% of (b) is 12min, tau2>20％τ1And defrosting and frosting.
And step 9: instantaneous heating quantity q when unit begins to defrost21.7kW, instantaneous heating capacity q in the frostless process 170% of (a) is 2.1kW, q2<70％q1The frost formation rate, calculated v, increased by 0.02 mm/h. After heat supply is recovered, the heating capacity q of the unit3Is 2kW, and the instantaneous heating capacity q in the frostless process 195% of (a) is 2.85kW, q3<95％q1Surface set temperature T of evaporator coilsThe increase was 0.1 ℃.
Step 10: using the adjusted calculated frosting rate v and the set surface temperature T of the evaporator coilsThe monitoring of the next duty cycle is started.
Example 3
Step 1: monitoring outdoor ambient temperature TaAt-9 deg.C and relative humidity RH of 75%, and ambient temperature T at this air state pointaAnd the relative humidity RH is higher than 50 percent and is lower than 6 ℃, and the next operation is carried out.
Step 2: will measure the outdoor ambient temperature TaAnd the relative humidity RH is input into the fuzzy controller to judge which frosting area the air state point is in. Outdoor ambient temperature TaWhen the air state point is in the moderate frosting area O at the temperature of minus 9 ℃ and the relative humidity RH is 75 percent, the air state point is in the moderate frosting area O, and the frosting rate v is calculated to be 0.7 mm/h.
And step 3: calculating the thickness of the frost layer by using the frosting rate v in the step 2 as 0.7mm/h, wherein the last defrosting effect is good and no frost layer is accumulated, and h is0The time interval delta tau monitored by the heat pump unit is 60s and the accumulated growth thickness h of the frost layer is 0mm10.0117 mm. The fin spacing of the outdoor evaporator of the heat pump unit is 1.5mm, the half 0.5d of the fin spacing is 0.75mm, and the cumulative growth thickness h of the frost layer1<0.75mm, return to step 2.
And 4, step 4: after the step 2 and the step 3 are circulated for 64 times, the accumulated growth thickness h of the frost layer is monitored for 65 times650.758mm and is more than half of the fin spacing of the outdoor evaporator by 0.75mm, starts the defrosting operation, and records the instantaneous heating quantity q when the unit starts defrosting at the moment2Is 2.2 kW.
And 5: monitoring actual defrosting time tau of unit2Is 10min, the surface temperature T of the evaporator coilwThe heating capacity q of the heat pump unit is 21 ℃ when the defrosting is finished3Is 2.8 kW;
step 6: actual defrosting time tau of unit2Is 10min, the minimum heating time tau of the unit110% of (b) is 6min, tau2>10％τ1And entering judgment of ending defrosting.
And 7: surface temperature T of evaporator coilwIs 21 ℃ higher than the set temperature T of the surface of the evaporator coilsAnd 20 ℃, and finishing defrosting.
And 8: instantaneous heating quantity q when unit begins to defrost22.2kW, instantaneous heating capacity q in frostless process 170% of (a) is 2.1kW, q2>70％q1The frost formation rate, calculated v, decreased by 0.02 mm/h. After heat supply is recovered, the heat pump unit heats the heat quantity q32.8kW, instantaneous heating capacity q in frostless process 195% of (a) is 2.85kW, q3<95％q1Surface set temperature T of evaporator coilsThe increase was 0.1 ℃.
And step 9: using the adjusted calculated frosting rate v and the set surface temperature T of the evaporator coilsThe monitoring of the next duty cycle is started.
The embodiment shows that the method combines the frosting map with the fuzzy control, utilizes the fuzzy controller to judge the frosting degree to give the frosting rate, and calculates the frosting thickness, thereby reasonably selecting the defrosting starting point, and being an effective frosting control method of the fuzzy subarea frosting map.
The present invention is not limited to the above-mentioned embodiments, and based on the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some technical features without creative efforts according to the disclosed technical contents, and these substitutions and modifications are all within the protection scope of the present invention.

Claims (5)

1. A frost control method based on a fuzzy partition frosting map is characterized by comprising the following steps:
step 1: for outdoor ambient temperature TaMonitoring relative humidity RH, judging whether the air state point is in a frosting area U, if so, performing the next step, otherwise, monitoring again;
will measure the outdoor ambient temperature TaThe relative humidity RH is divided into a severe frosting area PB, a heavy frosting area PS, a moderate frosting area O, a light frosting area NS and a light frosting area NB from large to small, and the frosting area U is divided into the severe frosting area PB, the heavy frosting area PS, the moderate frosting area O, the light frosting area NB and the light frosting area NS from heavy frosting to light frosting;
step 2: inputting the outdoor environment temperature and humidity frosting monitoring values into a fuzzy controller, judging which area of a frosting area the air state point is specifically located in according to a fuzzy control rule formulated by a frosting map, and simultaneously giving a frosting rate calculation value;
the fuzzy inference rule is as follows:
Figure FDA0003354963230000011
and step 3: calculating the thickness h of the frost layer under the heating working condition by using the frosting rate in the step 2i：
hi＝hi-1+vΔτ
Wherein h isiIs the thickness of the frost layer in i time intervals, i is the number of times the time interval is recorded, hi-1The growth thickness of the frost layer in the first i-1 time interval, delta tau is the monitored time interval, and v is the frosting rate;
when the thickness of the frost layer exceeds 1/2 of the distance d between the fins of the evaporator coil of the outdoor heat pump unit, the heat pump unit starts defrosting, and the actual defrosting time tau of the unit is carried out2And evaporator coil surface temperature TwMonitoring, otherwise, returning to the step 2;
and 4, step 4: when the unit actually defrosts time tau2Not less than minimum heating time tau of unit1After 10%, entering judgment of ending defrosting, otherwise, monitoring actual defrosting of the unit againTime of frost τ2And evaporator coil surface temperature Tw；
And 5: surface temperature T of evaporator coilwGreater than or equal to the set temperature T of the surface of the evaporator coilsAnd defrosting is finished; otherwise, the actual defrosting time tau of the unit is set2Judging; when the unit actually defrosts time tau2Reaching the minimum heating time tau of the unit120%, defrosting is finished, otherwise, the actual defrosting time tau of the heat pump unit is monitored again2And evaporator coil surface temperature Tw；
Step 6: evaluating the starting point and effect of last defrosting, calculating the frosting speed v and the set temperature T of the surface of the evaporator coilsSelf-adjustment is performed.
2. The frost control method based on the fuzzy partition frosting map of claim 1, wherein in step 1, the air condition point in the frosting area is satisfied with both the ambient temperature being lower than 6 ℃ and the relative humidity being higher than 50%.
3. The frost control method based on the fuzzy partition frosting map of claim 1, wherein in step 2, according to fuzzy inference rules of fuzzy controller, it is determined which region of the frosting area the air state point is in the blurred map, and an initial calculated value of frosting rate v is given: the initial set value of the speed of each frosting area is the median of the interval, the frosting speed of the light frosting area NB is 0.1mm/h, the frosting speed of the light frosting area NS is 0.35mm/h, the frosting speed of the medium frosting area O is 0.7mm/h, the frosting speed of the heavy frosting area PS is 1.1mm/h, and the frosting speed of the heavy frosting area PB is 1.6 mm/h.
4. The frost control method based on the fuzzy partition frosting map according to claim 1, wherein in the step 6, the method for evaluating the defrosting starting point and the defrosting effect is as follows:
instantaneous heating quantity q if the unit starts defrosting2Greater than the instantaneous heating capacity q in the frostless process170% of (a), the frosting rate calculated by v is reduced by 0.02 mm/h; instantaneous heating quantity q if the unit starts defrosting2Instantaneous heating capacity q less than or equal to frostless process170% of (A), the frost-formation rate, calculated v, increases by 0.02 mm/h.
5. The method as claimed in claim 1, wherein in step 6, the calculated frosting rate v and the set evaporator coil surface temperature T are calculatedsSelf-adjustment is carried out by the following method:
after heat supply is recovered, if the heat pump unit heats the heat quantity q3Instantaneous heating capacity q in frostless process or more1And 95 percent of the total temperature, the evaporation temperature set value is reduced by 0.1 ℃; if the heating capacity q of the heat pump unit3Less than instantaneous heating capacity q in frostless process195% of the evaporation temperature set point, the evaporation temperature set point is increased by 0.1 deg.c.
CN202010586598.2A 2020-06-24 2020-06-24 Frost control method based on fuzzy partition frosting map Expired - Fee Related CN111678280B (en)

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CN110094925B (en) * 2019-05-08 2023-12-29 南京工程学院 Evaporator frosting detection method and defrosting application
CN112484237B (en) * 2020-11-20 2022-06-24 珠海格力电器股份有限公司 Defrosting control method, device and equipment and air conditioner
CN112413820A (en) * 2020-11-23 2021-02-26 珠海格力电器股份有限公司 Air conditioner defrosting method and device, air conditioning equipment and computer readable storage medium
CN114440453B (en) * 2022-03-01 2024-01-16 北溪特(浙江)科技有限公司 Air energy water heater frosting degree judging method based on fuzzy algorithm

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