JPH0577933B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) 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. (Prior art) While maintaining a high energy efficiency EER during heating operation, by taking into account the state of the defrosting operation that was performed immediately before the current heating operation,
JP-A No. 62-294836 is proposed as an improvement on JP-A-62-294836, which improves operating economy by defrosting at an appropriate timing according to the actual situation of heating operation. The present applicant previously made a proposal in Publication No.-294836. This known technology is based on the relationship between the degree to which the heating capacity, which is determined by the temperature difference Δt between the inflow and outflow and inlet of the heated fluid, e.g., indoor air, in the user-side coil decreases with the progress of frost formation and the time required for defrosting. It is characterized by a control method that selects the timing when the integrated heating capacity in the cycle is maximum and performs defrosting. (Problem to be Solved by the Invention) When defrosting is performed using this control method, it is a rational 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 all the coils on the user side operate, 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 11,
To explain using an example where there are three coils on the user side, the temperature Δt is minimum when three coils are in full operation, and when two coils are in operation,
Since the temperature difference increases and decreases in the order of single unit operation, there is a problem that the above-mentioned known technique cannot be simply applied to a multi-system. Apart from this, in the case of a multi-system, there is the issue of which usage 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 all units are targeted for detection, but countermeasures must be taken such as 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, the compressor capacity is not adjusted by an inverter, for example, as shown by the solid lines in Figs. 12 and 13. , the temperature difference Δt changes due to frequency changes ₁ to ₄ , and the apparent heating capacity Q increases or decreases. Therefore, the heating capacity Q is integrated and the defrosting timing is determined based on the maximum value. However, it is clear that this alone does not result in 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 user side coils are connected in parallel to a single heat source side unit. In applying the shown defrosting control method, by adding a correction according to the number of operating coils on the user side in the process of calculating the cumulative heating capacity, it is possible to obtain appropriate defrosting timing. For those whose capacity is controlled, the defrosting timing can be optimized by adding a correction corresponding to the capacity change in the same calculation process, so that the defrosting operation starts neither too early nor too late. The purpose of this project is to improve the operating economy of a multi-system air conditioner by maintaining the highest EER value. (Means for Solving the Problems) As shown in FIG. It includes a means _2-1 , 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 outlet temperature and the inlet temperature of the heated fluid in each of the utilization side coils 13 _-1 and 13 _-2 during partial operation when a part is stopped and during full operation when a part is in full operation. Based on the fact that the temperature difference Δti from the temperature changes, and in the former case the smaller the number of operating vehicles, the larger the value, each correction coefficient αj determined in advance corresponding to the number of operating vehicles is stored in a readable manner. It has a configuration. Next, the modification coefficient selection means 2 _-1 detects the number of operating coils 13 _-1 and 13 _-2 on the user side currently in heating operation, and calculates the corresponding modification coefficient αj from the data stored in the modification coefficient storage means 1. It has a reading configuration. On the other hand, the cumulative heating capacity calculation means 3 calculates the cumulative heating capacity S _io from the start of the heating operation immediately after the end of defrosting for each of the user-side coils 13 _-1 and 13 _-2 during the heating operation at a fixed time interval. The calculation is performed by periodically multiplying the correction coefficient αj read by the correction coefficient selection means 2 _-1 . Furthermore, the individual average heating capacity calculation means 4 calculates the cumulative heating capacity S _io calculated by the cumulative heating capacity calculation means 3 for each of the user-side coils 13 _-1 and 13 _-2 during heating operation from the previous defrosting. Divide by the value obtained by adding the previous defrosting operation time T _d or the next predicted defrosting operation time T _dy to the heating operation time T _f that has been performed since the end of the operation. Accordingly, the average heating capacity Q _io is calculated and stored. Next, the overall average heating capacity calculation means 5 calculates the average heating capacity Q _io calculated by the individual average heating capacity calculation means 4 for each of the user-side coils 13 _-1 and 13 _-2 during heating operation. It has a configuration that calculates and stores the overall average heating capacity _Qo . Further, regarding the comparison means 6, the overall average heating capacity calculated by the overall average heating capacity calculation means 5
The current value _Qo of _Qo is compared with the previous value Qo _-1, and when the current value is smaller, a defrost signal is output. Next, the description of claim 2 is a defrosting device for a multi-system air conditioner having a compressor 8 whose capacity is controlled, and as shown in FIG. 7 is added, a coefficient selection means _2-2 is provided in place of the correction coefficient selection means _2-1 , and the configuration of the cumulative heating capacity calculation means 3 is changed. Regarding the correction coefficient storage means 7, each correction coefficient βj is determined in advance in accordance with the capacity of the compressor on the basis that the temperature difference Δti fluctuates more as the capacity of the compressor 8 changes as the capacity decreases. It has a configuration that allows it to be stored in a readable manner. On the other hand, the coefficient selection means 2 _-2 detects the number of operating coils 13 _-1 and 13 _-2 currently in heating operation and the operating capacity of the compressor 8, and detects the correction coefficient storage means 1 and the correction coefficient. Coefficient storage means 7
The configuration is such that the corresponding correction coefficient αj and correction coefficient βj are read out from the stored data. In addition, regarding the cumulative heating capacity calculation means 3, when calculating the cumulative heating capacity S _io for each usage side coil 13 _-1 , 13 _-2 , not only the correction coefficient αj but also the
The configuration is such that the correction coefficient βj is also multiplied. In addition, there are two types of capacity control of the compressor 8: one is controlled steplessly by an inverter, and the other is controlled stepwise by an unloader device. In the former case, the correction coefficient stored in the correction coefficient storage means 7 is βj is determined corresponding to the change in frequency Hzn, while in the latter case, the correction coefficient βj is determined corresponding to the compressor capacity ratio % of the unloader device. (Function) The present invention uses the overall average heating capacity calculating means 5 to correct the fluctuation in the temperature difference Δti based on the difference in the number of operating coils 13 _-1 and 13 _-2 , and also Since the correction is made in the same way for If defrosting is required at this point, defrosting is started by detecting the peak point in time, so defrosting can be done at the correct timing and defrosting can be performed while always maintaining the maximum heating capacity value. It is possible to effectively frost. (Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings. FIG. 3 is a device circuit diagram according to an example of the present invention,
One heat source side unit OU is combined with a plurality of user side units IU ₁ , _{IU 2} . It is equipped with a heating pressure reducer 11 formed by connecting a switching valve 9, a heat source side coil 10, and a check valve 16 in parallel, an accumulator 14, and a heat source side fan 18, and has a connection part for a liquid pipe and a gas pipe at the pipe end. There is. Each user side unit IU ₁ , IU ₂ ... has the same structure, so to explain one of them, IU ₁ , there is a cooling pressure reducer 12 _-1 between the liquid pipe and the gas pipe, a user side coil 13 _-1 and It has electromagnetic valves 15 _-1 connected in series and a user side fan 19 _-1 , and a check valve 17 _-1 is connected in parallel to the pressure reducer 12 _-1 ,
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 of the solid arrow, and the user side coils _13-1 to 13 _-o act as condensers, and the heat source side coil 10 acts as an evaporator. On the other hand, during cooling operation and defrosting operation, the refrigerant is made to flow in the direction of the dashed arrow, and the heat source side coil 1
0 acts on the condenser, and the use side coils 13 _-1 and 13 _-o act on the evaporator, respectively. Needless to say, the flow direction of the refrigerant is changed by switching the four-way switching valve 9. In addition, in the case of defrost operation, the heat source side fan 18 and the user side fan 1
9 _-1 to 19 _-o are both stopped. In addition, in FIG. 3, 20 _-1 to 20 _-o are first temperature detectors that detect the air temperature at the outlet of the utilization side coils 13 _-1 and 13 _-o , and 21 -1 to 21 -o are the first temperature detectors that detect the air temperature at the outlet of the use side coils 13 _-1 and 13 _-o . Second temperature detectors for detecting air temperature are shown, and both temperature detectors 20 _-1 , 21 _-1 . . . 20 _-
o and 21 _-o constitute input elements of the cumulative heating capacity means 3, which will be described later. On the other hand, 23 is a de-Isa that detects the coil inlet temperature of the heat source side coil 10 which becomes an evaporator during heating operation and checks whether it is -5°C or lower and that 2 hours have passed since the built-in timer measures the heating operation time. The defrost detector is a known defrost detector that issues a defrost required signal under any of the above conditions, and is connected to an input terminal for a defrost command signal. The electronic control circuit that controls the defrosting of the air conditioner configured as described above is schematically shown in FIG. 4, and 24 is a well-known microcomputer.
It is configured with a CPU 25, RAM 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 performs arithmetic processing while exchanging data with the RAM 26 according to this program. The data processed accordingly is output to the output port 29. The output port 29 receives an output port designation signal from the CPU 25, temporarily stores data in that port, and sends an analog signal via the D/A converter 33 to the solenoid 9S of the four-way switching valve 8 _.
and the motor 19 of the user side fan 19 _-1 to 19 _-o
It is designed to output from _-1M to 19 _-oM . 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 . _p passes through the A/D converter 30 as a digital signal, the air inlet temperature T _i passes through the A/D converter 31 as a digital signal, and furthermore, the coil inlet temperature of the heat source side coil 10 detected by the de-icer 23 is converted into an A/D signal. The signals are outputted to input ports 28 as digital signals through converters 32, respectively. Accordingly, in claim 1, the program control in the microcomputer 24 includes the correction coefficient storage means 1, the correction coefficient selection means _2-1 , the integrated heating capacity calculation means 3, the individual average heating capacity 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, the coefficient selection means _2-2 , the integrated heating capacity calculation means 3, It is related to the configuration of the individual average heating capacity calculation means 4, the overall average heating capacity calculation means 5, and the comparison means 6,
A flowchart of the program written in the ROM 27 is shown in FIG. By the way, the theoretical basis for properly timing the start of defrosting is also clarified in the above-mentioned Japanese Patent Laid-Open No. 62-294836 when the 131 coils on the user side and the unit OU on the heat source side correspond. To summarize, when heating operation and defrosting operation are repeated alternately, the heating capacity, that is, the difference between the air outlet temperature T _p and the air inlet temperature T _i during heating of the user side coil. This value is proportional to the temperature difference Δt, but this heating capacity changes over time, and is zero at the start of heating operation, and as the operation progresses, the capacity increases until it reaches the maximum. When the temperature difference Δt _M , that is, reaches the maximum heating capacity, the capacity decreases as frost adheres and grows on the next heat source side coil, so the temperature difference Δt gradually decreases and reaches a state close to saturation. Therefore, from each temperature difference Δt 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, is integrated. After successively calculating the heating capacity value S, which is the integrated value obtained by
The average heating capacity Q divided by the sum of T _f and the predicted defrosting time T _dy required for defrosting when the current heating is switched to defrosting is calculated one after another. The average heating capacity Q thus obtained reaches its maximum just before frost formation occurs and defrosting operation is required, and then decreases. As is clear from the above points, if defrosting is performed by determining the time when the average heating capacity Q calculated in a certain period of time reaches its maximum, heating operation and defrosting operation can be performed while keeping the EER at its maximum. It becomes possible to
In short, when calculating the periodic average heating capacity Q, in order to find the conditions under which the value becomes maximum, it is sufficient to determine that the current calculated value is smaller than the previous calculated value. There is. Note that an appropriate value for the predicted defrosting time T _dy is determined from the relationship between the previous heating operation time (per time) and the previous defrosting time. When such a calculation method is applied to a multi-system air conditioner, there is a problem that the temperature difference Δt apparently increases or decreases depending on the number of units in operation, as described above, so the total By calculating the correction coefficient αj for each number of units in operation during partial operation using the operation time as a reference, storing it in a readable manner in the correction coefficient storage means 1, and multiplying it when calculating the cumulative heating capacity, the apparent A revised calculation can be made 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 small number whose absolute value becomes smaller as the number of stopped vehicles increases. According to the above explanation, in multi-system air conditioners, the temperature difference Δti is detected for all the coils on the user side, multiplied by a correction coefficient αj, and the average number of units in operation is integrated, and this tends to decrease. All you have to do is let it defrost at some point. That is, after calculating S _io = ΣαjΔtin Q _io = S _io /T _f + T _d (or T _dy ) for each unit,

[Formula] is calculated, and when the value tends to decrease, defrosting is performed. However, Qin: Integral capacity of each user coil, T _f : Heating operation (frosting) time, T _d : Defrosting operation time, N: Number of operating units, Qn: Overall average heating capacity, Defrosting is performed based on the above explanation. A flowchart for carrying out the operation will be explained with reference to FIGS. 5 to 8 regarding the invention of claim 1. Turn on the heating operation switch to start heating the air conditioner (step), and perform initial settings (step). This initial setting is to set the electronic timer to the heating operation time.
Reset T _f to zero, which is the starting point, and also reset the time T _fs from ON to zero, and set the integrated heating capacity value S _io
and average heating capacity Q are set to zero, and furthermore, since defrost operation has never been performed at the start of operation, an appropriate time interval such as 5 minutes is set as one of the conditions for determining the subsequent timing. This means setting the frost time _Td , setting the flag Flg to 0, and storing them in the microcomputer 24. Thus, the electronic timer starts the clock, and the measurement flow (step) shown in FIG. 6 is entered until the heating operation time T _f reaches 20 minutes (step). In other words, first check (step) that the heating operation is in progress, and every time a certain period of time (for example, 1 minute) is counted (step), all the user-side coils 13 _-1 , 13 _-2 . . . Air outlet temperature T _p and air inlet temperature T _i in order at intervals.
Calculate and store the temperature difference Δti (step). Note that the operation mode is unstable (uncertain factors exist) until about 20 minutes have passed from the start of operation, so the defrosting operation is not allowed to start during this time (step). While calculating each temperature difference Δti every minute, the flow (step) of temperature difference correction according to the number of operating coils 13 _-1 , 13 _-2 ... is performed on the operating coils 13 _-1 , 13 _- on the user side. At the same _time , the corrected temperature difference Δti is integrated (step) to obtain the integrated heating capacity _Sio , and since the flag Flg is 0 (step) due to startup, the next step is (Step 〓〓) and average heating capacity Q _io
The calculation and memory of the user side coil 1 during heating operation
Have them perform each of _3-1 and _13-2 . In addition,
Step 〓〓 corresponds to the processing function of the individual average heating capacity calculation means 4. In this case, the average heating capacity Q _io is determined by the set defrost time (T _d = 5 minutes) since defrost has not been performed before.
It is obtained by dividing the cumulative heating capacity S _o by the sum of the heating operation time T f and the heating operation time T _f . Note that the step and the steps described below correspond to the processing function of the integrated heating capacity calculation means 3. By the way, the flow (steps) of temperature difference correction
As shown in _{FIG .} After reading the value corresponding to the number of units in the step, move to the step and Δti=αj
This is to calculate ×Δti. Note that this step is the correction coefficient selection means 2 _-1
This corresponds to the processing function of And each user side coil 13 _-1 , 13 during operation
_-2 → After the calculation and memorization of the cumulative heating capacity S _io of the steps shown between → steps are completed.
Then, the calculation Q _p = _N 〓 ⁱ⁼¹ Q _io ÷N is performed. That is, the total average heating capacity _Qo is obtained by dividing the sum of the calculated average heating capacities _Qio by the number N of operating units. This step 〓〓 is the comprehensive average heating capacity calculation means 5
This is the processing function. In this way, the heating operation continues and checks (steps) that the time from the start of operation is within 180 minutes, and the restart time after automatic stop.
Check (step) whether T _fs is in an unstable period within 5 minutes, perform only the measurement flow (step) during the unstable period, and if it is in a stable period after 5 minutes, the average heating capacity calculated this time A comparison of the value Q _o and the previous value Q _o-1 is performed every minute in steps. If the comparison result is Q _o ≧ Q _o-1 , the measurement flow (step) is reached; on the other hand, if Q _o < Q _o-1 , the average heating capacity value Q _o exceeds the maximum value at that point and decreases. This means that the defrosting signal is output from the comparison means 6 when it is checked (step) that the time from restarting the operation is in a stable period of 5 minutes or more. Note that the step corresponds to the processing function of the comparing means 6. In this state, the coil temperature of the heat source side coil 10 is -
If the temperature is 5° C. or higher and the de-icer 23 is not emitting a defrost signal (step), the measurement flow (step) is continued, but if it is emitting a defrost signal, a transition is made to the defrost flow (step). This defrost flow is as shown in FIG. 8, and it switches the heating cycle to the cooling cycle and also switches the heating operation time T _f
After performing an initial setting (Step 〓〓) of fixing Td to the current value Tu and resetting the defrost operation time _Td to zero, the defrost operation time is measured in units of one minute (Step 〓〓). 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 higher than the completed defrosting and issues a defrosting release signal (Step 〓〓). , is the coefficient of the formula for calculating the predicted defrosting operation time T _dy 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 (T _d − 1)/T _u =
After performing the calculation a, a cycle end set is performed in which the heating operation time T _f is reset to zero, the integrated heating capacity value S _io and the average heating capacity Q _io are reset to zero, and the flag Flg is set to 1 (step 33). . In this step, if it is checked that three hours have passed since the start of the heating operation, and if it is also checked that the frost detection signal is being emitted from the de-icer 23, the microcomputer 24 determines that Q _o <
This is a check function that forces defrosting operation to start even if the calculation result of Q _o-1 is not available. In this way, one cycle consisting of the heating operation and the defrosting operation is completed, and the operation starts again from the step. However, the measurement flow (step) from the second cycle starts when the step is flagged in Fig. 6. 1, so we move on to the sequential operation of the right half. First, in step 〓〓, a predetermined calculation is performed to calculate the predicted defrosting operation time T _dy when heating operation is switched to defrosting operation at the current time. The above calculation result may be used as is in the calculation of step 〓〓, but considering the degree of safety,
In steps 〓〓〓, the predicted defrosting operation T _dy is compared with the time T _d required for the previous defrosting.
However, it is a preferable means to define the upper limit value and the lower limit value so that it falls within the range of 0.5T _d ≦T _dy ≦1.5T _d . When the predicted defrosting operation time _Tdy is calculated in this manner, the process proceeds to step 〓〓 of the processing procedure by the individual average heating capacity calculating means 4. In other words, the user side coils 13 _-1 , 13 during operation
_-2 , the average heating capacity _Qio is calculated by dividing the cumulative heating capacity value _Sio up to the present by the sum of the current cumulative heating operation time _Tf and the predicted defrosting operation time _Tdy . . After calculating the overall average heating capacity _Qo in the overall average heating capacity calculation means 5, this calculation procedure is carried out until the comparison means 6 checks Q _o < Q _o-1 and switches to defrosting operation. The steps are the same as in the first cycle. In this way, since the defrosting operation is performed by checking the point at which the average heating capacity Q _o reaches its maximum, it is possible to perform the heating and defrosting operations alternately when the EER is at its highest. Next, regarding the invention of claim 2, this is a so-called multi-type air conditioner equipped with a compressor 8 whose capacity is controlled, and whose capacity is adjusted steplessly by an inverter 22, for example. In this case, as shown by the solid lines in FIGS. 13 and 14, the temperature difference Δt changes due to frequency changes ₁ to ₄ , and the apparent heating capacity Q _io increases or decreases, so this heating capacity Q _io In the above-mentioned defrosting control method, which integrates and determines the defrosting timing based on the maximum value, it is not always possible to obtain the optimal defrosting timing. Therefore, when we conducted an experiment to determine what effect a change in the output frequency of the inverter 22 had on a change in the temperature difference Δti, we found that the lower the frequency, the greater the change. Based on this result, a temperature difference correction curve as shown in FIG. 12 is obtained, and a characteristic that the correction coefficient β becomes larger as the frequency becomes lower is stored in the correction coefficient storage means 7, with the correction coefficient 1.0 at the highest frequency as a reference. , temperature difference Δti depending on the output frequency during operation
If the integrated heating capacity S _io is calculated after multiplying by the correction coefficient 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 will be explained using figures. The temperature difference correction flow (step) in Fig. 6 is shown in Fig. 9, and at the same time the number of operating units of the currently operating coils _13-1 and _13-2 is received at the step, and at the same time the current output signal is received. When the frequency of the voltage is received at the step 〓〓, the corresponding correction coefficient αj and correction coefficient βj are read out from the data stored in the correction coefficient storage means 1 and the correction coefficient storage means 7 in the next step', and then the process proceeds to step'. Then, calculate Δti = αj × βj × Δti, correct the temperature difference value according to the number of operating coils on the user side and the capacity of the compressor, and calculate the following values for each of the user side coils 13 _-1 , 1
This is in preparation for calculating the cumulative heating capacity _Sio for _3-2 . Note that step' corresponds to the processing function of the coefficient selection means _2-2 , and step 18' corresponds to the processing function 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. Furthermore, _the temperature difference ( _constant for heating capacity,
Since processing is performed to correct the apparent increase/decrease in Δti), it is possible to set the optimal defrosting timing without being too early or too late for multi-system air conditioners, making it easier to use No matter how the number of operating side coils 13 _-1 and 13 _-2 changes, appropriate defrosting is possible while maintaining the maximum EER (Energy Effective Ratio) during heating operation. Further, the invention of claim 2 is a device that automatically controls the capacity of the compressor 8 by operating frequency conversion or the like of an inverter, and in which a temperature difference Δti caused by capacity switching is provided.
Since the fluctuation of the defrost is properly compensated for, the defrosting timing is not extended or shortened and the appropriate defrosting timing can be reliably achieved. When using an unloader device, the frequency Hzn can be easily and accurately corrected by using the compressor capacity ratio % as a 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; 5 to 9 are flowcharts showing defrosting control modes, and FIGS. 10 to 14 are characteristic diagrams illustrating the effects of the present invention. DESCRIPTION OF SYMBOLS 1... Correction coefficient storage means, 2 _-1 ... Correction coefficient selection means, 2 _-2 ... Coefficient selection means, 3... Cumulative heating capacity calculation means, 4... Individual average heating capacity calculation means, 5... Overall Average heating capacity calculation means, 6...Comparison means, 7...Correction coefficient storage means, 8...Compressor, _13-1 , _13-2 ...Using side coil, OU...
Heat source side unit.

Claims (1)

[Claims] 1. In an air conditioner in which a plurality of user side coils 13 _-1 and 13 _-2 are connected in parallel to a single heat source side unit OU, partial operation in which a part of the unit is stopped The temperature difference Δti between the outlet temperature and the inlet temperature of the fluid to be heated in each utilization side coil 13 _-1 , 13 _-2 fluctuates depending on the time of full operation and the full operation. a correction coefficient storage means 1 for readably storing each correction coefficient αj determined in advance in accordance with the number of units in operation on the basis that the smaller the value, the larger the value _; ,13 _-2
correction coefficient selection means 2 _-1 that detects the number of operating units and reads out the corresponding correction coefficient αj from the data stored in the correction coefficient storage means 1; and for each of the utilization side coils 13 _-1 and 13 _-2 during heating operation, Cumulative heating capacity calculation that calculates and stores the cumulative heating capacity S _io from the start of heating operation immediately after the end of defrosting by multiplying it by the correction coefficient αj read out by the correction coefficient selection means 2 _-1 periodically at fixed time intervals. The integrated heating capacity S io calculated by the integrated heating capacity calculation means 3 for each of the means 3 and the user-side coils 13 _-1 and 13 _-2 during heating operation is calculated from the cumulative heating capacity S _io calculated by the integrated heating capacity calculation means 3 after the previous defrosting operation is completed. The average heating capacity Q _io can be calculated by dividing the heating operation time T _f that has been performed up to now by the sum of the previous defrosting operation time T _d or the next predicted defrosting operation time T _dy . The individual average heating capacity calculation means 4 calculates and stores the individual average heating capacity, and the individual average heating capacity calculation means 4 for each of the user-side coils 13 _-1 and 13 _-2 during heating operation.
an overall average heating capacity calculation means 5 that calculates and stores an overall average heating capacity Q _o corresponding to the average value of each average heating capacity Q _io calculated by; and an overall average heating capacity calculated by the overall average heating capacity calculation means 5. An air conditioner characterized by comprising a comparison means ₆ for comparing the current value Q _o and the previous value Q _o-1 of Q o and outputting a defrosting signal when the current value is small. Defrost equipment. 2 In an air conditioner in which multiple user side coils _13-1 , _13-2 are connected in parallel to a single-system heat source side unit OU having a capacity-controlled compressor 8, a part of the unit stops. The temperature difference Δti between the outlet temperature and the inlet temperature of the heated fluid in each user side coil 13 _-1 , 13 _-2 varies between partial operation with full operation and full operation with full operation. a correction coefficient storage means 1 for readably storing each correction coefficient αj determined in advance according to the number of operating units on the basis that the smaller the number of units in operation, the larger the value; correction coefficient storage means 7 for readably storing each correction coefficient βj determined in advance in accordance with the capacity of the compressor on the basis that the lower the capacity, the larger the change in capacity;
and the user-side coils _13-1 and _13-2 currently in heating operation.
coefficient selection means 2 _-2 for detecting the number of operating units and the operating capacity of the compressor 8 and reading out the corresponding correction coefficient αj and correction coefficient βj from the data stored in the correction coefficient storage means 1 and the correction coefficient storage means 7; , For each of the user-side coils 13 _-1 and 13 _-2 during heating operation, the integrated heating capacity S _io from the start of heating operation immediately after the end of defrosting is periodically determined by the coefficient selection means 2 _-2 at fixed time intervals. The cumulative heating capacity calculation means 3 calculates and stores the product by multiplying the correction coefficient _αj and the correction coefficient _βj read by The calculated integrated heating capacity S _io is calculated by adding the heating operation time T _f that has been carried out since the end of the previous defrosting operation to the present time to the previous defrosting operation time T _d or the next expected predicted defrosting operation. The individual average heating capacity calculation means 4 calculates and stores the average heating capacity Q _io by dividing by the value added to the frost operation time T _dy , and each of the user side coils 13 _-1 and 13 _-2 during heating operation. , the individual average heating capacity calculation means 4
an overall average heating capacity calculation means 5 that calculates and stores an overall average heating capacity Q _o corresponding to the average value of each average heating capacity Q _io calculated by; and an overall average heating capacity calculated by the overall average heating capacity calculation means 5. An air conditioner characterized by comprising a comparison means ₆ for comparing the current value Q _o and the previous value Q _o-1 of Q o and outputting a defrosting signal when the current value is small. Defrost equipment. 3. The defrosting device for an 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 an output frequency Hzn of the inverter. 4. The defrosting device for an air conditioner according to claim 2, wherein the capacity of the compressor 8 is controlled in stages by the unloader device, and each correction coefficient βj is determined corresponding to a compressor capacity percentage of the unloader device.