JP2909941B2 - Defrosting operation control device for refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defrosting operation control device for a refrigeration system, and more particularly to an improvement in a defrosting operation control device which starts a defrosting operation based on a change in average heating capacity.

[0002]

2. Description of the Related Art Conventionally, as a defrosting operation control device for a refrigeration system, for example, a refrigeration system having a compressor whose operating frequency is variably adjusted by an inverter as disclosed in Japanese Patent Laid-Open No. 41748/1988. In the apparatus, the temperature difference between the outlet and the inlet of the medium to be heated of the use side heat exchanger is periodically calculated, and the temperature difference is calculated in advance based on the fact that the temperature difference increases as the inverter frequency decreases and decreases as the inverter frequency increases. While storing the relationship of the correction coefficient to the resulting frequency as function information, the integrated heating capacity from the start of the heating operation immediately after the end of defrosting, the outlet-inlet temperature difference and the correction coefficient corresponding to the frequency at that time, based on the value obtained by multiplying the cyclically calculated and stored, the integration Heating
The average heating capacity is calculated by dividing the capacity by the sum of the heating operation time from the start of the heating operation to the present time and the set predicted defrosting operation time to calculate the average heating capacity. Is a known technique that outputs a defrost signal when the current value is small.

[0003]

SUMMARY OF THE INVENTION The defrosting operation control device for a refrigeration system disclosed in the above-mentioned conventional publication detects the frost formation state of the use side heat exchanger from the decrease in the heating capacity,
It is intended to set an optimal defrost start timing. That is, as shown in FIG. 7, the temperature difference ΔTn between the outlet and the inlet of the medium to be heated is measured, and the heating capacity Q during the period Δt is measured.
m is obtained as follows: Qm = Δt · ΔTn, and after the defrosting operation is completed, a time t from the start of the heating operation is calculated.
The accumulated heating capacity Sn until f elapses is represented by the following equation: Sn = ΣQm (see the hatched portion in FIG. 8). Therefore, the average heating capacity Qn between the heating operation time tf and the predicted defrost operation time tdy is expressed by the following equation: Qn = Sn / (tf + tdy) (However, in the figure, the previous defrost operation The time is referred to as a predicted defrosting operation time tdy).

[0006] As shown in FIG. 9, during heating operation, the average heating capacity Qn up to that time is periodically obtained, and when the change is plotted, the average heating capacity Qn increases as the heating operation progresses. However, when frost is formed on the heat source side heat exchanger, the heating capacity is reduced accordingly, and a point in time when the average heating capacity Qn is reduced occurs (see point Qe in FIG. 9).
At this point, by outputting the defrost command, the entry timing to the defrost operation can be accurately determined.

[0005] In particular, in the above conventional apparatus, the outlet-inlet temperature difference ΔTn of the medium to be heated changes in a complicated manner depending on the inverter frequency, that is, the operating capacity of the compressor, and the apparent accumulated heating capacity Sn increases and decreases under the influence thereof. In view of the above, by correcting the outlet-inlet temperature difference by the inverter frequency,
It is intended to improve the accuracy of the defrost control and, consequently, the EER.

In this case, the relationship between the inverter frequency and the correction coefficient is based on the change characteristic of the outlet-inlet temperature difference with respect to the inverter frequency obtained by the experiment of the refrigeration system. However, there is a problem that it is inconvenient to apply it as it is.

[0007] The present invention has been made in view of such a point, and an object thereof is that the outlet temperature of the medium to be heated of the use side heat exchanger changes according to the condensation temperature of the use side heat exchanger. The outlet-inlet temperature difference of the use-side heat exchanger changes according to the condensing temperature of the refrigerant, and the condensing temperature changes according to the inverter frequency, and when the model such as the rated capacity of the compressor is determined, it depends on the inverter frequency. Focusing on the fact that the change characteristic of the outlet-inlet temperature difference is almost constant, simplifying the application to each refrigeration system by formulating the relationship between the inverter frequency and the correction coefficient with a regression equation determined by the type of compressor. It is to plan.

[0008]

In order to achieve the above-mentioned object, the present invention provides a compressor (1) whose frequency is variably adjusted by an inverter, as shown in FIG. Heat source side heat exchanger (3) and decompression mechanism (5)
And a refrigeration apparatus provided with a refrigerant circuit (9) in which the refrigerant circuit (9) is sequentially connected to the use side heat exchanger (6).

An inlet temperature detecting means (Thr) for detecting the inlet temperature (Ti) of the medium to be heated of the use side heat exchanger (6) is provided as a defrosting operation control device of the refrigerating apparatus. Outlet temperature (To) of the medium to be heated in the exchanger (6)
Temperature detection means (The) for detecting the temperature and the outputs of the two temperature detection means (Thr) and (The), and at regular intervals, the outlet temperature (To) and the inlet temperature (Ti) during the heating operation. Outlet-inlet temperature difference (ΔTn)
And a temperature difference calculating means (51) for calculating a temperature difference based on a correlation between an inverter frequency (Hz) and a condensing temperature based on a predetermined frequency of an inverter which gives a temperature difference corresponding to the heating capacity. 51) Model of the compressor (1) as a function of the inverter frequency (Hz) as a correction coefficient (XD5) for converting the outlet-inlet temperature difference (ΔTn) calculated in 51) into the outlet-inlet temperature difference at the predetermined frequency. a correction equation storing means (11) for storing for each, depending on the inverter frequency (Hz), the calculated outlet at said temperature difference calculation means (51) - the inlet temperature difference (.DELTA.Tn) the correction equation storing means (11) Correction means (52) for correcting by the correction coefficient (XD5) stored in the storage means, and correction by the correction means (52).
When the temperature difference (ΔTnh) is negative, the temperature difference
A re-correction means (56) for re-correction to “0”; and an integrated heating capacity (S) from the start of the heating operation after the completion of defrosting.
The n), the outlet being corrected by the correction means (53) - the inlet temperature difference (DerutaTnh) and re-correction by the re-correcting means (56)
An integrated heating capacity calculating means (53) for periodically calculating based on the obtained temperature difference; a heating operation time (tf) from the heating operation start time to the present; and a predicted defrosting operation time (t
By dividing the integrated heating capacity (Sn) calculated by the integrated heating capacity calculating means (53) by the sum with dy),
The average heating capacity calculation means (54) for calculating the average heating capacity (Qn) and the current calculation value (Qk) of the average heating capacity (Qn) calculated by the average heating capacity calculation means (54) are calculated in the previous calculation. A defrosting signal output means (55) for outputting a defrosting signal when the current calculated value is smaller than the value (Qk-1)
Is provided .

[0010]

With the above arrangement, according to the first aspect of the present invention, the integrated heating capacity calculating means (53) and the average heating capacity calculating means (53) are based on the temperature difference ΔTn (= To−Ti) between the outlet and the inlet of the medium to be heated. 54), the integrated heating capacity Sn and the average heating capacity Qn are calculated, and the defrosting signal output means (55) determines that the heating capacity is reduced from the peak value of the average heating capacity and that the heat source side heat exchanger (3) is frosted. A defrost start timing is determined, and a defrost command is issued.

On the other hand, the correction-type storage means (11) stores the outlet-inlet temperature difference ΔTn based on the predetermined frequency of the inverter that provides the outlet-inlet temperature difference corresponding to the heating capacity, at the predetermined frequency. Is stored as a function of the inverter frequency Hz, and the outlet-inlet temperature difference ΔTn is corrected by the correcting means (53) using the correction coefficient XD5 obtained by the correction formula according to the inverter frequency. Therefore, the corrected outlet-inlet temperature difference ΔTnh is an accurate indicator of the heating capacity.
Since the integrated heating capacity Sn and the average heating capacity Qn are calculated based on the corrected outlet-inlet temperature difference ΔTnh, erroneous determination of the defrost rush timing due to a change in the condensing temperature due to the inverter frequency is caused. Therefore, the start of the defrosting operation is determined.

In particular, when the outlet-inlet temperature difference ΔTnh corrected by the correction means (52) becomes negative, the outlet-inlet temperature difference ΔTnh is set to “0” by the re-correction means (56).
The outlet temperature T which may occur under special conditions
Due to the reversal of o and the inlet temperature Ti, a calculation error of the average heating capacity Qn occurs, which prevents the rush time to the defrosting operation from being mistaken, and the determination of the defrosting operation rush time is performed more accurately. .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

FIG. 2 shows a refrigerant piping system of an air conditioner to which the present invention is applied, which is a so-called separate type in which one outdoor unit (A) is connected to one indoor unit (B). is there. The outdoor unit (A) has a compressor (1) whose operating frequency is variably adjusted by an inverter (not shown), and switches as indicated by a solid line in the cooling operation and as indicated by a broken line in the heating operation in the heating operation. A four-way switching valve (2), an outdoor heat exchanger (3), which is a heat source side heat exchanger functioning as a condenser during cooling operation and as an evaporator during heating operation, and a decompression unit (2) for decompressing refrigerant.
0) and an accumulator (7) interposed in the suction pipe of the compressor (1) for removing liquid refrigerant in the suction refrigerant are arranged as main devices. In the indoor unit (B), an indoor heat exchanger (6), which is a use-side heat exchanger that functions as an evaporator during the cooling operation and as a condenser during the heating operation, is arranged. The above devices are sequentially connected by a refrigerant pipe (8), and a refrigerant circuit (9) is configured to generate heat transfer by circulation of the refrigerant.

The pressure reducing section (20) is provided with a receiver (4) for storing the liquid refrigerant and an electric expansion valve (5) having a function of reducing the liquid refrigerant and a function of adjusting the flow rate. The auxiliary heat exchanger of the outdoor heat exchanger (3) is connected to the receiver (4) and the electric expansion valve (5) such that the electric expansion valve (5) communicates with the lower part of the receiver (4), that is, the liquid part. (3a)
Are arranged in series on the common path (8a) via And, between the outdoor heat exchanger (3) and the end (P) of the common path (8a) on the upstream side of the receiver (4), the flow of refrigerant from the outdoor heat exchanger (3) to the receiver (4). An indoor heat exchange between the point (P) of the common path (8a) and the indoor heat exchanger (6) by a first inflow path (8b1) through a first check valve (D1) that permits only the first check valve (D1). (6) to receiver (4)
Connected via a second check valve (D2) allowing only the flow of refrigerant to the second inflow path (8b2), while being connected to the electric expansion valve (5) and the like in the common path (8a). Between the end (Q) on the end side and a point (R) between the second check valve (D2) and the indoor heat exchanger (6), the electric expansion valve (5) to the indoor heat exchanger (6). The point (Q) of the common path (8a) and the first check valve (D1) through the first outflow path (8c1) via the third check valve (D3) that permits only the flow of refrigerant to the first check valve (D1). A fourth check valve (D4) that allows only refrigerant to flow from the electric expansion valve (5) to the outdoor heat exchanger (3) between the point (S) between the outdoor heat exchangers (3); Via the second outflow channel (8c2)
Are connected to each other.

Further, between the point (P) on the upstream side of the receiver (4) and the point (Q) on the outflow side, a liquid ring prevention bypass passage (8f) having a capillary tube (C) interposed therebetween. )
The liquid ring prevention bypass passage (8f) is provided to prevent liquid seal when the compressor (1) is stopped. A bypass pipe (4a) for bypassing the gas refrigerant from the upper part of the receiver (4) to the downstream side of the electric expansion valve (5) via the on-off valve (SV) to ensure the refrigerant storage function of the receiver (4). Is provided. The degree of pressure reduction of the capillary tube (C) is set to be sufficiently larger than that of the electric expansion valve (5).
The function of adjusting the refrigerant flow rate by the electric expansion valve (5) during the normal operation can be favorably maintained.

Incidentally, (F1 to F4) are filters for removing dust in the refrigerant, and (ER) is a muffler for reducing the operation noise of the compressor (1).

Further, sensors are provided in the air conditioner, (Th2) is disposed in the discharge pipe, a discharge pipe sensor for detecting the temperature of the discharge pipe, and (Tha) is the air suction of the outdoor unit (A). The outdoor suction sensor (Thc), which is disposed in the mouth and detects the intake air temperature, which is the outside air temperature, is disposed in the outdoor heat exchanger (3), and becomes the condensing temperature during the cooling operation and becomes the evaporation temperature during the heating operation. An external heat exchange sensor for detecting the temperature, (Thr) is disposed at the air suction port of the indoor unit (B), and detects an intake air temperature Ti that is the inlet temperature of the medium to be heated. The internal heat exchange sensor (HPS), which is disposed in the heat exchanger (6) and detects the internal heat exchange temperature that becomes the condensing temperature during the heating operation as the outlet temperature To of the medium to be heated, turns on due to an excessive rise in the high pressure side pressure. The protection device described below ( 1 high pressure switch, which actuates the) (LPS) is a low pressure switch for actuating the protective device (11) turned on by excessive reduction of the low-pressure side pressure. The signals from the sensors are inputably connected to a controller (10) for controlling the operation of the air conditioner, and the controller (10) operates the air conditioner in accordance with the signals from the sensors. Has been made to control.

Here, the controller (10) includes:
A storage device (11) as a correction expression storage means for storing a relational expression between an inverter frequency Hz and a correction coefficient XD5, which will be described later
And an arithmetic circuit (12) for arithmetically processing various data during operation. In the storage device (11) , the correction coefficient XD5 is set in advance as a function of the inverter frequency Hz as in the following equation (1) XD5 = A + B · Hz + C · Hz ² (1). Then, this formula (1)
The coefficients A, B, and C of the respective terms are determined by the type of the compressor, such as the rated capacity, and are, for example, quadratic regression curves (xo),
(X1).

For example, in the case of the quadratic regression curve (x1), when the inverter frequency Hz is 60 (Hz) (point X1),
Since the outlet-inlet temperature difference ΔTn gives an accurate heating capacity, the correction coefficient XD5 becomes substantially “1”. Then, based on the frequency value 60 (Hz), the inverter frequency H
This is obtained by plotting a correction coefficient XD5 for converting the outlet-inlet temperature difference ΔTn when z changes to the outlet-inlet temperature difference when the inverter frequency is 60 (Hz). It is almost a quadratic regression curve,
It can be a higher-order regression equation of third order or higher. In the curve (xo), the frequency value at the point (Xo) is the predetermined frequency.

In the refrigerant circuit (9), during the cooling operation, the liquid refrigerant condensed and liquefied in the outdoor heat exchanger (3) flows in from the first inflow path (8b1) and passes through the first check valve (D1). After being stored in the receiver (4) and decompressed by the electric expansion valve (5), the refrigerant is vaporized in the indoor heat exchanger (6) through the first outflow passage (8c1) and returned to the compressor (1). While
During the heating operation, the liquid refrigerant condensed and liquefied in the indoor heat exchanger (6) flows in from the second inflow path (8b2), is stored in the receiver (4) through the second check valve (D2), and is electrically expanded. After the pressure is reduced by the valve (5), the refrigerant is evaporated in the outdoor heat exchanger (3) through the second outflow passage (8c2) and returns to the compressor (1).

At this time, the opening degree of the electric expansion valve (5) is determined using the discharge pipe temperature T2 detected by the discharge pipe sensor (Th2) as a parameter. That is, a discharge pipe temperature (optimum temperature Tk) that gives an optimal refrigeration effect is calculated from the condensation temperature and the evaporation temperature detected by the external heat exchange sensor (Thc) and the internal heat exchange sensor (The), and the discharge pipe temperature is calculated. The opening of the electric expansion valve (5) is controlled so that T2 becomes the optimum temperature Tk.

When a defrost command is received during the heating operation, the four-way switching valve (2) is switched to the cooling cycle side,
Hot gas is introduced into the outdoor heat exchanger (3) to melt frost on the outdoor heat exchanger (3).

Next, control contents during the heating operation will be described with reference to the flowchart of FIG.

In step ST1, it is determined whether or not the vehicle is in the operating state. If the vehicle is not in the operating state, the count value tfs of the heating operation time is set to "0" in step ST2. . First, steps ST3 and S
At T4, the heating operation time tf is counted, and at step ST5, a temperature difference ΔTn (= To−Ti) between the air blowing temperature To and the air suction temperature Ti is calculated, and then, at step ST6.
Then, the correction coefficient XD5 is calculated based on the correction equation XD5 = f (Hz) determined by the above equation (1).

Then, in step ST7, ΔTnh = ΔT
n / XD5, that is, the temperature difference ΔTn obtained in step ST5 is corrected by the correction coefficient XD5, and the value is set as the corrected temperature difference ΔTnh. In steps ST8 and ST9, a process for setting the calculated value when the temperature difference ΔTnh becomes negative depending on the operating conditions to “0” is performed, and then in step ST10.
Then, the cumulative heating capacity Sn is added.

Next, in step ST11, a flag Flg which becomes "0" is determined only in the first cycle after the start of operation, and if it is the first cycle, step ST12.
The average heating capacity Qn is calculated based on the following equation (2) Qn = Sn / (td + tf) (2) In this case, since the defrost has not been performed yet, the set defrost time t
The cumulative heating capacity Sn is divided by the sum of d (for example, about 5 minutes) and the heating operation time tf.

On the other hand, from the next cycle after defrosting, the flag Flg is set to "1" at the discrimination of step ST11, and the routine proceeds to step ST13, where the following equation is obtained.
(3) tdy = a · tf + 1 (3) Based on (3), the predicted defrosting operation time tdy is calculated. However,
The coefficient a is calculated as follows based on the previous heating operation time tu and the previous defrosting operation time td, assuming that the time lag required for switching the function of the evaporator-condenser in the defrosting-heating switching is approximately 1 minute. (4) a = (td -1) / tu (4)

Next, in steps ST14 to ST17, in consideration of the degree of safety, the predicted defrosting is performed in order to prevent the calculation result from being too far from the previous defrosting operation time td due to erroneous detection of the sensor or the like. The operating time tdy is set to the lower limit 0.5td.
And the upper limit value 1.5td, and then the step ST1 is performed.
In step 8, the average heating capacity Qn is calculated based on the following equation (5): Qn = Sn / (tdy + tf) (5)

Next, the average heating capacity Qn is controlled by the above control.
Is calculated, the flow proceeds to the determination control of the entry timing to the defrosting operation. FIG. 4 shows the contents of the judgment control of the entry timing to the defrosting operation. In step SS1, the average heating capacity Qk calculated in the current control is compared with the average heating capacity Qk-1 calculated in the previous control. If Qk is not equal to or smaller than Qk-1, the process proceeds to step SS2, in which the number of times of decrease CD1 is subtracted from CD1 = CD1-1. The process of setting to "0" is performed, and the process returns to the control of step SS1 without outputting the defrosting operation command.

On the other hand, if it is determined in step SS1 that Qk ≦ Q
At k-1, since the average heating capacity Qn decreased,
The process proceeds to step SS5 to count the number-of-times-of-reduction count value CD1, and in the determination of step SS6, repeats the above-mentioned control without issuing a defrosting operation command until CD1 reaches 10 or more. , Then step SS7
Then, it is determined that CD1 = 10, that is, the average heating capacity has reached a peak, and a defrosting operation command is output.

In the above flow, the control of step ST5
The temperature difference calculating means (51) is constituted by
The correction means (52) is constituted by the control of ST7,
The integrated heating capacity calculating means (5
3) is configured, and the average warming is controlled by the control of step ST10.
The cell capacity calculating means (54) is constituted, and
The defrost signal output means (55) is constituted by the control.I
You. AlsoBy the control of step ST9,Re-correction means
(56) is constituted.

Therefore, in the above embodiment, during the heating operation, based on the temperature difference ΔTn (= To−Ti) between the outlet temperature To and the inlet temperature Ti of the medium to be heated, the integrated heating capacity calculating means (53) and the average The heating capacity calculating means (54) calculates the integrated heating capacity Sn and the average heating capacity Qn,
The defrosting signal output means (55) determines the defrosting start time when the decrease in the heating capacity is the time of the frost formation of the heat source side heat exchanger (3) from the peak value of the average heating capacity, and the defrosting command is issued. Done.

At this time, if the compressor (1) whose frequency is variably adjusted by the inverter is provided, the compressor (1)
Changes the refrigerant circulation amount and the condensing temperature of the refrigerant in the indoor heat exchanger (6) serving as a condenser, that is, the outlet temperature To of the medium to be heated changes.
The outlet-inlet temperature difference ΔTn also changes, and the outlet-inlet temperature difference Δ
Tn is not always an accurate indicator of heating capacity.
That is, as shown in FIG. 6, the average heating capacity Qn is calculated to be apparently smaller (broken curve q1) or larger than the true change (solid curve qo) (broken curve q2).
). Then, since the entry timing to the defrosting operation is determined based on the average heating capacity Qn, there is a possibility that the entry to the defrosting operation may be entered at a time deviated from the true frosting time (at the time Q1e in FIG. Time point Q2e).

Here, in the above embodiment, the correction means (5
According to 2), the temperature difference ΔTn is corrected using the correction coefficient XD5 obtained by the quadratic regression equation (1) stored in the storage device (11) in advance as a function of the inverter frequency Hz. -The inlet temperature difference ΔTnh is an accurate indicator of the heating capacity. Then, based on the outlet-inlet temperature difference ΔTnh corrected based on the regression equation (1), the integrated heating capacity Sn and the average heating capacity Qn are calculated, so that it is possible to accurately determine the start of the defrosting operation. It is possible (Qoe in the figure).

When the outlet-inlet temperature difference ΔTnh corrected by the correction means (52) becomes negative by the re-correction means (56), it is corrected to “0”, thereby further improving the calculation accuracy. . For example, immediately after returning from the defrost operation, the suction air temperature Tr may be lower than the condensation temperature Tc, and in such a case, the outlet-inlet temperature difference Δ
Although Tnh becomes negative, the heating capacity does not actually become negative. Therefore, if the calculation is continued as it is, the average heating capacity Qn may be calculated to be smaller than the actual value. However, the re-correction means (56) performs the re-correction to determine the defrosting operation entry timing. It can be done more accurately.

In the above embodiment, the outlet-inlet temperature Δ
When obtaining Tn, the outlet temperature To of the indoor heat exchanger (6) was obtained from the internal heat exchange temperature Tc.
That value may be used as the outlet temperature To.

In the above embodiment, the medium to be heated is conditioned air. However, the present invention is not limited to this embodiment. For example, hot water is generated in the use-side heat exchanger. Is similarly applicable.

[0039]

As described above, according to the first aspect of the present invention, as a defrosting operation control device for a refrigeration system, the temperature difference between the outlet and the inlet of the medium to be heated of the use side heat exchanger is periodically obtained. Then, the cumulative heating capacity and the average heating capacity are sequentially calculated from the values, a defrosting command is output when the average heating capacity decreases, and a predetermined frequency of the inverter frequency that provides a temperature difference corresponding to the heating capacity is used as a reference. A correction coefficient for converting the value of the outlet-inlet temperature difference into a value at a predetermined frequency is stored in advance as a function of the inverter frequency for each model of the compressor, and the outlet-inlet temperature difference is calculated based on the correction coefficient. Since the correction is made, it is possible to correct the outlet-inlet temperature difference, which is a value deviating from the index of the heating capacity due to a change in the condensing temperature according to the inverter frequency, to an accurate index of the heating capacity. Te, it is possible to improve the timing determination accuracy of the defrosting operation inrush.

Further , when the corrected outlet-inlet temperature difference becomes a negative value, it is re-corrected to "0", so that the difference between the outlet temperature and the inlet temperature generated under specific conditions is obtained. integrated heating capacity in reversal of Kakeue it is possible to effectively prevent the actual calculated smaller than, therefore, the
The effect can be more remarkably exhibited.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a refrigerant piping system diagram of the air-conditioning apparatus according to the embodiment.

FIG. 3 is a flowchart showing control contents for calculating an average heating capacity.

FIG. 4 is a flowchart showing the control contents for judging the defrost entry time.

FIG. 5 is a diagram showing a quadratic regression curve of a correction coefficient with respect to an inverter frequency.

FIG. 6 is a characteristic diagram showing the effect of the present invention.

FIG. 7 is a characteristic diagram showing a time change of an outlet-inlet temperature difference.

FIG. 8 is a diagram for explaining a process of calculating an integrated heating capacity and an average heating capacity from an outlet-entrance temperature difference.

FIG. 9 is a diagram showing a change over time of an average heating capacity.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Compressor 3 Outdoor heat exchanger (heat source side heat exchanger) 5 Electric expansion valve (pressure reduction mechanism) 6 Indoor heat exchanger (use side heat exchanger) 9 Refrigerant circuit 11 storage device (correction type storage means) Thr Indoor suction Sensor (inlet temperature detecting means) The internal heat exchange sensor (outlet temperature detecting means) 51 Temperature difference calculating means 52 correcting means 53 integrated heating capacity calculating means 54 average heating capacity calculating means 55 defrosting command output means 56 re-correcting means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-41748 (JP, A) JP-A-4-90436 (JP, A) JP-A-63-194146 (JP, A) JP-A-63-194146 194145 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) F24F 11/02 F25B 47/02

Claims (1)

(57) [Claims] The frequency is variably adjusted by an inverter.
Compressor (1), heat source side heat exchanger (3), and decompressor
The structure (5) and the use side heat exchanger (6) are connected in order.
In the refrigerating apparatus provided with the refrigerant circuit (9), the inlet temperature (T
i) an inlet temperature detecting means (Thr), and an outlet temperature (T
o) detecting the output of the outlet temperature detecting means (The) and the outputs of the two temperature detecting means (Thr) and (The);
Outlet temperature (To) during heating operation at regular intervals
-Inlet temperature difference, which is the temperature difference between the temperature and the inlet temperature (Ti)
A temperature difference calculating means (51) for calculating (ΔTn); and a predetermined circuit of an inverter for providing a temperature difference corresponding to the heating capacity.
Inverter frequency (Hz) and condensation temperature based on wave number
And the temperature difference calculating means (51)
The calculated outlet-inlet temperature difference (ΔTn) is calculated using the above-mentioned predetermined frequency.
Coefficient to convert to outlet-inlet temperature difference in number
(XD5) compressed as a function of inverter frequency (Hz)
Correction type storage means for storing for each model of machine (1)(11)
And the temperature difference calculating means according to the inverter frequency (Hz).
The outlet-inlet temperature difference (ΔTn) calculated in (51) is
Correction type storage means(11)Correction coefficient (XD
Correction means (52) for correcting by (5),The temperature difference (ΔTnh) corrected by the correction means (52) is negative.
In this case, the temperature difference is re-corrected to be "0".
Correct means (56), The integrated heating capacity (S
n) is the outlet-inlet corrected by the correcting means (53).
Temperature difference (ΔTnh)And re-correction by the re-correction means (56)
Temperature differenceHeating capacity calculated periodically based on
Arithmetic means (53), heating operation time (tf) from the heating operation start time to the present time
And the predicted defrost operation time (tdy)
Integrated heating capacity calculated by the calculated heating capacity calculation means (53)
By dividing (Sn), the average heating capacity (Qn)
Means for calculating the average heating capacity (54), and the average heating capacity calculated by the means for calculating the average heating capacity (54).
The current calculated value (Qk) of the capacity (Qn) is replaced with the previous calculated value
(Qk-1)
Defrost signal output means (55) for outputting a frost signal.
A defrosting operation control device for a refrigerator.