JPH01312343A - Defrosting device for air conditioner - Google Patents

Abstract

PURPOSE:To improve an economical characteristic of operation through keeping of a maximum value of energy effective ratio under a suitable starting of defrosting operation by a method wherein a state to show a maximum value of mean heating capability is found through calculation in respect to a phenomenon of reducing a heating capability caused by a frosted condition and a control for changing-over it to a defrosting operation is carried out in response to this state. CONSTITUTION:A calculated heating capability value Sin up to present is divided by a sum of a present heating operation time and an estimated defrosting operation time for each of utilization coils 13-1 and 13-2 during operation, thereby each of mean heating capabilities Qin is calculated. After calculation of a total means heating capability Qn in a total mean heating capability calculating means 5 for this order of calculation, a check of a relation of Qn<Qn-1 is performed and this is carried out until the operation is changed over to a defrosting operation. In this way, a time in which the means heating capability Qn is made maximum is checked and the defrosting operation is carried out, so that it is possible to perform an alternative heating and defrosting operation under a maximum energy effective ratio.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a defrosting device for an air conditioner such as an air source heat pump in which a plurality of user side coils are connected in parallel to a single heat source side unit. .

(Conventional technology) While maintaining a high effective energy ratio (EER) during heating operation, by taking into consideration the state of defrosting operation that was performed immediately before the current heating operation, it is possible to Japanese Patent Laid-Open No. 62-29483 discloses a system that improves operating economy by defrosting at the right timing.
The present applicant previously made a proposal in Publication No. 6.

This known technology is based on the relationship between the degree to which the heating capacity, which is determined by the temperature difference (△L) between the inflow and outflow and inlet of the heated fluid in the user-side coil, such as indoor air, decreases with the progress of frost formation and the time required for defrosting. This system is characterized by a control method that defrosts the air by selecting the timing at which the integrated heating capacity in one cycle is maximum based on the relationship.

(Problem to be Solved by the Invention) When defrosting is performed using this control method, it is a reasonable control mode when the heat source side unit and the user side unit having one user side unit correspond to each other. A so-called multi-system air conditioner in which a plurality of utilization side coils are connected in parallel to a single heat source side unit is unlikely to be optimal, and this point will be explained below.

In the case of a multi-system, there is a full operation in which two coils are operated on the user side, and a partial operation in which some of the coils are stopped.If the number of operating coils is different, the refrigerant flow state in the refrigeration circuit will naturally change, causing the blowout air to change. Because the temperature changes, even if the heating capacity is calculated using the temperature difference between the outlet and intake air and the defrosting timing is determined, appropriate results will not be obtained.

This is as shown in Figure 1). To explain this using an example in which there are three coils on the utilization side, the temperature (△t) is minimum when three coils (all) are in operation, and when two coils are in operation, one coil is in use. Since the temperature difference increases and decreases in the order of unit operation, there is a problem that the above-mentioned known technique cannot be simply applied to the multi-system.

Apart from this, in the case of a multi-system, there is the issue of which user side coil's intake/outlet air temperature difference should be detected. If the coil on the user side is operating, heating capacity cannot be calculated, so countermeasures must be taken such as detecting all units or switching target units.

Furthermore, in the case of an air conditioner in which the capacity of the compressor in the heat source side unit is controlled according to the load, Fig. 12 and 1
As shown by the solid line in Fig. 3, for example, in the case where the compression function is adjusted by an inverter, the frequency changes r, ~f4.
The temperature difference (△t) changes, and the apparent heating capacity (B) increases or decreases, so this heating capacity (Q) is integrated and the defrosting timing is determined based on the maximum value. However, it is clear that this alone is not the optimal timing.

Therefore, if the capacity of the compressor is controlled, it is necessary to take corrective measures commensurate with the change in capacity.

The present invention has been made to address these problems, and is particularly applicable to air conditioners in which a plurality of utilization side coils are connected in parallel to a single heat source side unit. In applying the shown defrosting control method, a correction according to the number of operating coils on the user side is added in the process of calculating the cumulative heating capacity, so that appropriate defrosting timing can be taken. For those that are controlled, the defrosting timing is optimized by adding a correction corresponding to the capacity change in the same calculation process, so that the defrosting operation starts neither early nor late, and the EER reaches the highest value. The purpose is to improve the operating economy of multi-system air conditioners through maintenance.

(Means for Solving the Problems) Therefore, as shown in FIG. It includes a coefficient selection means (L1), an integrated heating capacity calculation means (3), an individual average heating capacity calculation means (4), an overall average heating capacity calculation means (5), and a comparison means (6). .

First, the correction coefficient storage means (1) records the heated coils (13, -1), (13-1) for each utilization side coil (13, -1), (13-1) during partial operation when a part is stopped and during full operation when a part is in full operation. The temperature difference (△ti) between the outlet temperature and the inlet temperature of the fluid fluctuates, and in the former case, the smaller the number of operating units, the larger the value. It has a configuration in which the correction coefficient (αj) is stored in a readable manner.

Next, the correction coefficient selection means (2-1) detects the number of operating coils (13-1) and (t3-2) on the user side currently in heating operation, and stores the number in the correction coefficient storage means (1). It has a configuration for reading out a corresponding correction coefficient (αj) from data.

On the other hand, the cumulative heating capacity calculation means (3) calculates the cumulative heating capacity (Si ) is read out by the correction coefficient selection means (2, 1) periodically at regular intervals.
j) is calculated and stored.

Furthermore, regarding individual average heating capacity calculation means (4),
User side coil (LL1) during heating operation (+3-2)
For each, the cumulative heating capacity (Sin) calculated by the cumulative heating capacity calculation means (3) is calculated by calculating the heating operation time (Sin) performed from the end of the previous defrosting operation to the present.
The configuration calculates and stores the average heating capacity (Qin) by dividing Tf) by the sum of the previous defrosting operation time (Tf) or the next predicted defrosting operation time (Tay). have

Next, the overall average heating capacity calculation means (5) calculates each average heating capacity () calculated by the individual average heating capacity calculation means (4) for each of the heating operation time utilization side coils (13-1) and (13-2). It has a configuration that calculates and stores the overall average heating capacity (Qn) corresponding to the average value of Qin).

Regarding the comparison means (6), the overall average heating capacity (lower) calculated by the overall average heating capacity calculation means (5)
The current value (Q, l) is compared with the previous value (Q, l), and when the current value is smaller, a defrosting signal is output.

Next, the invention of claim 2 is a defrosting device for a multi-system air conditioner having a compressor (8) whose capacity is controlled,
As shown in the figure, a correction coefficient storage means (7) is added to the invention of claim 1, and a correction coefficient selection means (L
The present invention is characterized in that a coefficient selection means (2-2) is provided in place of step 1), and the configuration of the integrated heating capacity calculation means (3) is further modified.

Regarding the correction coefficient storage means (7), the temperature difference (
A configuration in which each correction coefficient (βj) determined in advance in accordance with the capacity of the compressor is stored in a readable manner based on the fact that Δti) fluctuates more as the capacity changes with respect to the capacity change of the compressor (8). has.

On the other hand, regarding the coefficient selection means (2-2), the user side coils (13-1), (13-2) currently in heating operation
detects the number of operating units and the operating capacity of the compressor (8),
Corresponding correction coefficients (αj) and correction coefficients (βj) are read out from the data stored in the correction coefficient storage means (1) and the correction coefficient storage means (7).

In addition, regarding the cumulative heating capacity calculation means (3), when calculating the cumulative heating capacity (Stfi) for each user side coil (13-1), (13-2), not only the correction coefficient (αj) but also the above-mentioned It has a configuration in which a correction coefficient (βj) is also multiplied.

In addition, there are two types of capacity control of the compressor (8): one that is controlled steplessly by an inverter, and one that is controlled stepwise by an unloader device. The correction coefficient (βj) to be stored is determined by the frequency (
In the latter case, the correction coefficient (βj) is determined corresponding to the compressor capacity ratio (%) of the unloader device.

(Function) The present invention corrects the fluctuation of the temperature difference (△ti) based on the difference in the number of operating coils (13-1) and (13-2) using the overall average heating capacity calculation means (5), and Since the change in capacity of the compressor (8) is similarly corrected, it is possible to calculate the heating capacity in accordance with the actual operating conditions.
Judgments suitable for multiple methods can be realized, and a comparison method (
In combination with 6), the point in time when the overall average heating capacity reaches its peak is detected, and if defrosting is required at this point, defrosting is started, so accurate defrosting timing can be taken. It is possible to defrost effectively while always maintaining the heating capacity value at the maximum.

(Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 3 is a circuit diagram of an apparatus according to an example of the present invention, in which a plurality of utilization side units (■υ1), (IU2)...(10,) are connected to one heat source side unit (OU). The heat source side unit (OU) consists of a compressor (8) having a morph controlled by an inverter (22), a four-way switching valve (
9) A heating pressure reducer αυ consisting of a heat source side coil αψ and a check valve αe connected in parallel, an accumulator αa and a heat source side fan α, and a connection part for a liquid pipe and a gas pipe at the piping end. There is.

Each user unit (to1), (ru2)... has the same structure, so to explain one of them (IU1), there is a cooling pressure reducer (12-1) between the liquid pipe and the gas pipe.
, user side coil (13-,') and solenoid valve (15-1)
are connected in series, and a user side fan (19-
1), and the pressure reducer (12-1) is provided with a check valve (17).
-1) are connected in parallel, and this refrigerant circuit is connected to the liquid/gas pipe of the heat source side unit (OU).

By configuring the refrigeration circuit in this way, during heating operation, the refrigerant flows in the direction indicated by the solid line arrow, and the user side coils (13, 1) to (13-1) are used as condensers, and the heat source side coils 00 ) on the evaporator, and on the other hand, during cooling operation and defrost operation, the refrigerant is made to flow in the direction indicated by the dashed line, and the heat source side coil QOI is applied to the condenser and user side coil (13-1). ) to (13-, 1) are applied to the evaporator, and it goes without saying that the refrigerant flow direction is changed by switching the four-way selector valve (9), and in the case of defrost operation, , heat source side fan Q8
1 and the user side fans (19-1) to (19□) are both stopped.

In FIG. 3, (2L1) to (20-n) are the first temperature detectors (21-1) that detect the air temperature at the outlet of the utilization side coils (13-1) to (13-, 1). )～(21
−. ) respectively indicate second temperature detectors that similarly detect the air temperature at the inlet, and both temperature detectors (20-1).

(21-1)...-(20-, 1), and (21-n) constitute input elements of an integrated heating capacity means (3) to be described later.

On the other hand, (23) detects the coil inlet temperature of the heat source side coil 00) which becomes the evaporator during heating operation with a de-Isa, and
This is a well-known defrost detector that issues a defrost required signal depending on whether the temperature is below C or if two hours have passed since the built-in timer measured the heating operation time, and the defrost command signal is connected to the input end of the

The electronic control circuit for defrosting control of the air conditioner having the above configuration is schematically shown in FIG. 4, where (24) is a well-known microcomputer, CPU (25), l?
It is configured with AM (26) and ROM (27) as basic elements.

A program to control the CPU (25) is written in the ROM (27), and the CPU (25) reads external data from the input port (28) or exchanges data with the RAM (26) according to this program. It performs arithmetic processing while doing so, and outputs the processed data to the output port (29) as necessary.

The output port (29) receives the output port designation signal from the CPU (25), temporarily stores the data in that port, and also connects the D/A converter (33) to the II7 analog signal to the four-way switching valve (8). ) solenoid (91)
and the motor of the user side fan (LL1) to (19□) (
IL,1) to (19-,,M).

On the other hand, when the input port (28) receives an input port designation signal from the CPU (25), it takes in the information necessary for that port. ), the air outlet temperature (To) passes through the A/D converter (30) as a digital signal, and the air inlet temperature (T9) passes through the A/D converter (31) as a digital signal, and then the deaiser (23) outputs the air inlet temperature (T9) as a digital signal. The detected coil inlet temperature of the heat source side coil 00) is output as a digital signal to the respective input ports (28) via the A/D converter (32).

Accordingly, in claim 1, the program control in this microcomputer (24) includes the correction coefficient storage means (1), the correction coefficient selection means (2-1), and the integrated heating capacity calculation means (3) 2 individual average heating capacities. Calculation means (4),
In relation to the configuration of the overall average heating capacity calculation means (5) and the comparison means (6), in claim 2, the correction coefficient storage means (1), the correction coefficient storage means (7), and the coefficient selection means (
L2), integrated heating capacity calculation means (3) 1 individual average heating capacity calculation means (4), overall average heating capacity calculation means (5)
and related to the configuration of the comparison means (6), R
A flowchart of the program written in OM (27) is shown in FIG.

By the way, the theoretical basis for properly timing the start of defrosting is based on the above-mentioned Japanese Patent Laid-Open No. 62-294 when one user coil Qm and the heat source unit (OU) correspond to each other.
As clarified in Publication No. 836, and if we go beyond this, when heating operation and defrosting operation are repeated alternately, the heating capacity, that is, the air outlet temperature (Tf) during heating of the utilization side coil ) and air inlet temperature (T
This value is proportional to the temperature difference (△t), which is the difference between the As the capacity increases, the maximum temperature difference (△tx) increases. In other words, when the maximum heating capacity is reached, the capacity decreases as frost attaches and grows on the next heat source coil, so the temperature difference (△t) It gradually decreases and reaches a state close to saturation.

Therefore, from each temperature difference (△t) read every predetermined time from the start of heating operation, for example every 30 seconds or every 1 minute, the integral value from the start of operation to the present time, that is, the heating capacity equivalent value Heating capacity (!), which is the integrated value obtained by integrating
: After successively calculating (S), this heating capacity value (
S) is the heating operation time (Tf) that has been carried out since the end of the previous defrosting operation and the predicted defrosting time required for defrosting when the current heating is switched to defrosting. (r
The average heating capacity (Q) divided by the sum of dy) is calculated one after another.

The average heating capacity (0) thus obtained reaches its maximum just before frost formation occurs and requires defrosting operation, and thereafter it decreases.

As is clear from the above points, if defrosting is performed by determining the time when the average heating capacity (Q) calculated over a certain period of time is at its maximum, the EER can be maintained at its maximum and both heating and defrosting operations can be performed. In short, when calculating the periodic average heating capacity (b), in order to find the conditions that maximize the value, it is necessary to find the condition that the current calculated value is smaller than the previous calculated value. This means that it is sufficient to judge.

Note that the predicted defrosting time (Tdy) is based on the previous heating operation time (
An appropriate value can be found from the relationship between (per time) and the previous defrosting time.

When such a calculation method is applied to a multi-method air conditioner, the temperature difference (△t
) may increase or decrease in appearance, so as shown by the broken line in Figure 10, the correction coefficient (αj) for each number of vehicles in operation during partial operation is determined in advance and read out based on the full operation. storing the correction coefficient in the correction coefficient storage means (1),
By multiplying this when calculating the cumulative heating capacity, it becomes possible to calculate the apparent value by taking into account the above fluctuations.

In this case, as is clear from FIG. 10, when the correction coefficient during full operation is set to 1, the correction coefficient during partial operation is expressed as a decimal number whose absolute value becomes smaller as the number of stopped vehicles increases.

According to the above explanation, in a multi-system air conditioner, the temperature difference (Δti) is detected for all the user side coils, multiplied by a correction coefficient (αj), and the average number of operating units is integrated, and this decreases. You can start defrosting when this tendency occurs.

In other words, for each 5in==Σαj△tin After calculating, It is used to defrost when a tendency occurs.

However, Qin: Integral ability of each user side coil, Tf;
Heating operation (frost formation) time, T4: Defrosting operation time, N: Number of operating units Qn: Overall average heating capacity, Fig. 5 shows a flowchart for performing the defrosting operation based on the contents explained above. This will be explained with reference to FIGS.

Turn on the heating operation switch to start heating the air conditioner (step ■), and perform initial settings (step ■).

This initial cent is the heating operation time (Tf) of the electronic timer.
Reset to zero, which is the starting point of , and set the time since ON (
T□) is also reset to zero, and the cumulative heating capacity value (Sin) and average heating capacity (B) are set to zero, respectively.Furthermore, since defrost operation has never been performed at the start of operation, the Condition 1 for timing
This means setting an appropriate defrosting time (Td) such as 5 minutes, setting a flag (Flg) to 0, and storing them in the microcomputer (24).

In this way, the electronic timer starts measuring time and the heating operation time (T
Until f) reaches 20 minutes (step ■), the measurement flow shown in FIG. 6 (step ■) is entered.

That is, it first checks (step ■) that it is in the heating operation state, and then counts a certain period of time (e.g. 1 minute).
For each step 0, 0), all the utilization side coils (1)),
H3-2)...Then, at intervals of several seconds, the temperature difference (△) between the air outlet temperature (To) and the air inlet temperature (Tf) is
ti) is calculated and stored (step ■).

In addition, since the operating mode is unstable (uncertain factors exist) until about 20 minutes have passed from the start of operation, the defrosting operation is not started in step (3) during this period.

While calculating each temperature difference (Δti) every minute, the flow (step This is performed for each coil on the user side (13-1) and (t3-2), and at the same time, the temperature difference (△ti) after this correction is integrated (Step @l) to obtain the integrated heating capacity (Sl), respectively. , Since the flag (12g) is 0 due to startup (step [phase]), the calculation and storage of the average heating capacity (Qin1) is performed by moving to the next step ■. ), (13-2). Note that step (2) corresponds to the processing function of the individual average heating capacity calculation means (4).

Since defrosting has not been performed before, the average heating capacity (Qin) in this case is calculated as the cumulative heating capacity (S7) by the sum of the set defrosting time (Td = 5 minutes) and the heating operation time (Tf). It is found by dividing.

Note that the step [phase] and the step [phase] described later correspond to the processing function of the integrated heating capacity calculation means (3).

By the way, the flow of temperature difference correction (step
1), (1:L2) is received at step 0, the correction coefficient (αj
), the value corresponding to the number of operating vehicles is read out in step @, and then the process moves to step @ to calculate Δti=αj×Δti.

Note that this step O corresponds to the processing function of the correction coefficient selection means (2-1).

And each user side coil (13-1) in operation, (13
-2), once the calculation and storage of the cumulative heating capacity (Sin1) of the steps indicated between ■ and ○ has completed, the sum of each calculated average heating capacity (Qi.) is calculated as the number of operating units (N). The overall average heating capacity (Q
Find n).

This step [phase] is the overall average heating capacity calculation means (5)
This is the processing function.

In this way, the heating operation continues and checks that the time from the start of operation is within 180 minutes (step ■),
In addition, it is checked (step ■) whether the operation restart time (Tfs) after automatic stop is within 5 minutes during an unstable period, and only the measurement flow (step ■) is performed during the unstable period.
If it is a stable period after a minute has elapsed, the average heating capacity value (Ql) calculated this time is compared in magnitude with the previous value (Q, -1) at step 2 every minute.

If the comparison result is 07≧Qn −1, the measurement flow (
On the other hand, if Qn <Qr+ -1, it means that at that point the average heating capacity value (Qn) has passed the maximum value and is in the process of decreasing. If you check that the time from restart is a stable period of 5 minutes or more (step ■), the comparison method (
6) outputs a defrosting signal. - Note that step (2) corresponds to the processing function of the comparison means (6).

In this state, if the coil temperature of the heat source side coil 00) is 15°C or higher and the de-icer (23) does not issue a defrosting signal (step ■), the measurement flow (step ■) is continued; If a defrost signal is being issued, the defrost flow (step [phase]) is entered.

This defrost flow is as shown in FIG. 8, and the heating cycle is switched to the cooling cycle, and the heating operation time (T) is determined by the electronic timer.

) to the current value (Tu ) and reset the defrost operation time (T4) to zero (step 0), then measure the vehicle position for one minute of the defrost operation time (step [phase] )I do.

As a result of the defrosting operation being started in the cooling cycle and the frost being melted, the de-icer (23) detects that the coil temperature is 15°C or more after the completion of defrosting and issues a defrosting release signal (step [ ), and the equation for calculating the predicted defrosting operation time (Tdy) in the case where the cooling cycle is switched to the heating cycle and the heating operation is switched to the defrosting operation at the current point in step (32). The coefficient is (Tf −1)/T.

After calculating = a, the heating operation time (Tr) is set to zero, the cumulative heating capacity value (Sin) and the average heating capacity value (Qin).
Reset to zero and set the flag (F 1 g) to 1
(Step 3)
3). In addition, step ■ checks that 3 hours have passed since the start of heating operation, and also that the de-heater (23
), the microcomputer (24) detects the frost formation detection signal.
<This is a check function to forcefully enter defrosting operation even if the calculation result of Qn -I is not available.

In this way, one cycle consisting of heating operation and defrosting operation is completed, and the operation from step ① is performed again.
The measurement flow (step ■) from the second cycle is as follows:
In FIG. 6, the step [phase] has a flag of 1, so the process moves to the sequential operation in the right half.

First, in step O, a predetermined calculation is performed to calculate the predicted defrosting operation time (Tda) when heating operation is switched to defrosting operation at the current time.

The above calculation result may be carried directly into the calculation in step 0, but for safety reasons, it should be checked in steps 0 to 7 and compared with the time (Tf) required for the previous defrosting. The predicted defrosting operation time (Tdy) is 0.5 Ta≦Tdy≦1.5T.

It is a preferable means to define the upper and lower limits so that they fall within the range of .

When the predicted defrosting operation time (Tdy) is calculated in this way,
The process proceeds to step 0 of the processing procedure by the individual average heating capacity calculation means (4).

In other words, the user side coil (13-1) during operation, (1
3pe) Current cumulative heating operation time (Tf) for each
) and the predicted defrosting operation time (Tdy) to calculate each average heating capacity (Qin) by dividing the cumulative heating capacity value (Sin) up to now.

After calculating the overall average heating capacity (Qn) in the overall average heating capacity calculation means (5), this calculation procedure is performed in the comparison means (6).
In the same way as in the first cycle, the process is continued until a check is made for Qn<QI, -1 and the operation is switched to defrosting operation.

In this way, the time when the average heating capacity (Qn) reaches its maximum is checked and the defrosting operation is performed. '
It is possible to perform heating and defrosting alternately under the best conditions.

Next, regarding the invention of claim 2, this is an air conditioner called a multi-type equipped with a compressor (8) whose capacity is controlled, and for example, the capacity is controlled steplessly by an inverter (22). When the adjustment is performed, the temperature difference (Δt) changes depending on the frequency changes f1 to f4, as shown by the solid lines in FIGS. 13 and 14, and the apparent heating capacity (Qi) changes.
Since n) increases and decreases, the above-mentioned defrost control method that integrates the heating capacity (Qin) and determines the defrost timing based on its maximum value does not necessarily provide the optimal defrost timing.

Therefore, when we conducted an experiment to determine how the change in the output frequency of the inverter (22) affects the change in temperature difference (△ti), we found that the frequency is significantly lowered. .

Based on this result, a temperature difference correction curve as shown in FIG. 12 is obtained, and the correction coefficient storage means determines the characteristic that the correction coefficient (β) becomes larger as the frequency becomes lower, with the correction coefficient (1, 0) at the highest frequency as a reference. (7), and correct the temperature difference (△ti) according to the output frequency during operation.
If the integrated heating capacity (Sin1) is calculated after multiplying by β), it becomes possible to calculate the appropriate defrosting timing as shown by the broken lines in FIGS. 13 and 14.

Based on the content explained above, the flowchart for the defrosting operation according to the invention of claim 2 is shown in FIGS. This is explained by:

The temperature difference correction flow (step @) in Fig. 6 is shown in Fig. 9, and the currently operating utilization side coil (13
-1), (13-1) is received at step [phase], and at the same time, the frequency of the currently output voltage is received at step O. At the next step d, the correction coefficient storage means (1) After reading out the corresponding correction coefficients (αj) and correction coefficients (βj) from the data stored in the correction coefficient storage means (7), the process moves to Stesovj and calculates △ti=αj×
Calculate βj × △ti and correct the temperature difference value according to the number of operating coils on the user side and the capacity of the compressor,
This prepares for the next calculation of the integrated heating capacity (Sin) for each of the user-side coils (13, 1) and (13-2).

Note that step O' corresponds to the processing function of the coefficient selection means (2-1), and steps [phase]' and [phase] correspond to the processing functions of the integrated heating capacity calculation means (3).

However, the subsequent calculation of the individual average heating capacity and the overall average heating capacity and the determination of the defrosting time are the same as in the example according to claim 1.

(Effects of the Invention) The invention as claimed in claim 1 is a control system that calculates a state in which the average heating capacity reaches its maximum value in response to a phenomenon in which the heating capacity decreases due to frost formation, and switches to defrosting operation in accordance with this state. In addition, multiple user-side coils (13-1) +
The apparent temperature difference (constant for heating capacity, △ti) due to the difference in the number of units operating simultaneously in (13-2) is corrected for the above increase/decrease, so for multi-system air conditioners It is now possible to set the optimal defrosting timing that is neither too early nor too late, and no matter how the number of operating coils (13-1) and (t3-2) on the user side changes, the timing is maintained during heating operation. Appropriate defrosting is possible while maintaining the maximum EER (Energy Effective Ratio).

Further, the invention of claim 2 is a device that automatically controls the capacity of the compressor (8) by operating frequency conversion of an inverter, etc., and appropriately corrects fluctuations in temperature difference (△ti) caused by capacity switching. This makes it possible to ensure proper defrosting timing without extending or shortening the defrosting timing. can be easily and accurately corrected by using the compressor capacity ratio (%) as the detection element for correction.

[Brief explanation of the drawing]

1 and 2 are block diagrams showing the configurations of claims 1 and 2, FIG. 3 is a circuit diagram of a device according to an embodiment of the present invention, and FIG. 4 is an electronic control circuit for defrosting control; Figures 5 to 9
The figure is a flowchart showing a defrosting control mode, and FIGS. 10 to 14 are characteristic diagrams explaining the present invention in detail. (1)...Modification coefficient storage means, (2-1)...Modification coefficient selection means, (2-2)...Coefficient selection means, (3)...Cumulative heating capacity calculation means, (4 )...Individual average heating capacity calculation means, (5)...
Comprehensive average heating capacity calculation means, (6)... Comparison means, (7)... Correction coefficient storage means, (8)... Compressor, (13-1), (13-2)... User side coil, (
OU)...Heat source side unit. Figure 1 Isu Jk-Tani 1u Otsune de Maki Figure 2 + I rvj and no G fun se r two ila knee? )1 Figure 4 Figure 5 Figure 7 Figure 8 Figure 10 Figure 1) Figure 12 Figure 13

Claims (1)

[Claims] 1. In an air conditioner in which a plurality of user side coils (13_-_1), (13_-_2) are connected in parallel to a single heat source side unit (OU), The coils on each user side (13_-_1), (13_-__
2) The temperature difference between the outlet temperature and inlet temperature of the heated fluid (
△ti) changes, and in the former case, the smaller the number of vehicles in operation, the larger the value. Based on this, the correction coefficients (αj) determined in advance according to the number of vehicles in operation are stored in a readable manner. Coefficient storage means (1) and user side coils (13_-_1), (1) currently in heating operation
a correction coefficient selection means (2_-_1) for detecting the number of operating units of 3_-_2) and reading out a corresponding correction coefficient (αj) from the data stored in the correction coefficient storage means (1); and a use-side coil during heating operation. (13_-_1), (13_-_2)
For each, the cumulative heating capacity (S_i_n) from the start of heating operation immediately after the end of defrosting is multiplied by the correction coefficient (αj) read out by the correction coefficient selection means (2_-_1) periodically at fixed time intervals. Cumulative heating capacity calculation means (3) that calculates and stores it, and user-side coils (13_-_1), (13_) during heating operation.
-_2) For each, the cumulative heating capacity (S_i_n) calculated by the cumulative heating capacity calculation means (3) is calculated as the heating operation time (T_f) performed from the end of the previous defrosting operation to the present. , the previous defrosting operation time (T_d
) or the next predicted defrosting operation time (T_d_y)
The average heating capacity (Q_
individual average heating capacity calculation means (i_n) that calculates and stores
4) and the user side coil (13_-_1) during heating operation,
(13_-_2) For each average heating capacity (Q_i
Overall average heating capacity (Q_n) corresponding to the average value of __n)
a total average heating capacity calculation means (5) that calculates and stores the total average heating capacity calculation means (5), and a current value (Q_n) and a previous value (Q_n_-) of the total average heating capacity (Q_n) calculated by the said general average heating capacity calculation means (5). A defrosting device for an air conditioner, comprising: comparing means (6) that outputs a defrosting signal when the current value is smaller than the current value. 2. A plurality of utilization side coils (1
In an air conditioner in which 3_-_1) and (13_-_2) are connected in parallel, each user-side coil (13_-_1) is used during partial operation when a portion is stopped and during full operation when fully activated. , (13＿−＿
2) The temperature difference between the outlet temperature and inlet temperature of the heated fluid (
△ti) changes, and in the former case, the smaller the number of vehicles in operation, the larger the value. Based on this, the correction coefficients (αj) determined in advance according to the number of vehicles in operation are stored in a readable manner. coefficient storage means (1), and each coefficient determined in advance in accordance with the capacity of the compressor on the basis that the temperature difference (△ti) fluctuates more as the capacity of the compressor (8) decreases. A correction coefficient storage means (7) for readably storing the correction coefficient (βj), and user-side coils (13_-_1), (1) currently in heating operation.
3_-_2) and the operating capacity of the compressor (8) are detected, and the corresponding correction coefficient (αj) and Coefficient selection means (2_-_2) for reading out the correction coefficient (βj), and user-side coils (13_-_1), (13_) during heating operation.
-_2) For each, the cumulative heating capacity (S_i_n) from the start of heating operation immediately after the end of defrosting is determined by the correction coefficient (αj) and An integrated heating capacity calculating means (3) that calculates and stores the multiplied by a correction coefficient (βj), and a user side coil (13_-_1), (13_
-_2) For each, the cumulative heating capacity (S_i_n) calculated by the cumulative heating capacity calculation means (3) is calculated as the heating operation time (T_f) performed from the end of the previous defrosting operation to the present. , the previous defrosting operation time (T_d
) or the next predicted defrosting operation time (T_d_y)
The average heating capacity (Q_
individual average heating capacity calculation means (i_n) that calculates and stores
4) and the user side coil (13_-_1) during heating operation,
(13_-_2) For each average heating capacity (Q_i
Overall average heating capacity (Q_n) corresponding to the average value of __n)
a total average heating capacity calculation means (5) that calculates and stores the total average heating capacity calculation means (5), and a current value (Q_n) and a previous value (Q_n_-) of the total average heating capacity (Q_n) calculated by the said general average heating capacity calculation means (5). A defrosting device for an air conditioner, comprising: comparing means (6) that outputs a defrosting signal when the current value is smaller than the current value. 3. The air conditioner according to claim 2, wherein the compressor (8) is steplessly controlled in capacity by an inverter, and each correction coefficient (βj) is determined corresponding to the output frequency (Hz) of the inverter. Defrost equipment. 4. The air compressor according to claim 2, wherein the compressor (8) is subjected to capacity control in stages by the unloader device, and each correction coefficient (βj) is determined corresponding to the compressor capacity ratio (%) of the unloader device. Defrosting device for harmonizer.