JPH035652A - Air-conditioning apparatus - Google Patents

Abstract

PURPOSE:To improve the efficiency of heating under low outdoor temperature by a method wherein the time before the discharge-pipe temperature, after ending of defrosting, reaches a specified point is integrated and, according to the integrated time, the subsequent time during which the defrosting is prohibited is corrected. CONSTITUTION:A control device 11 outputs switching signals between the heating and defrosting in the operation on the basis of the pipe temperature of an outdoor heat exchanger 5 detected by a temperature sensor 10 and the duration of heating run, that is, the time during which the defrosting is prohibited, computed by a time- integrating means contained in the control device 11. With respect to the time required before the discharge-pipe temperature of a compressor 1, detected by a temperature sensor 12, reaches a specified point in the heating after a defrosting has been ended, a time-integrating means integrates the time and, depending on the length of the time thus obtained, corrects and decides the subsequent time during which the defrosting is prohibited. Thus an optimal timing can be achieved for a defrosting and the rise-time when the heating is restarted after defrosting can be shortened, so that the heating operation under low outdoor temperature can be performed efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a bomb-type air conditioner, particularly an air conditioner that can defrost in a timely manner during heating.

[Conventional technology]

FIG. 6 is a refrigerant circuit diagram showing the configuration of a conventional air conditioner. In the figure, 1 is a compressor, 2 is a four-way valve, 3 is an indoor heat exchanger, 4 is a heating capillary tube that is a flow rate control device, and 5
is an outdoor heat exchanger, 6 is an accumulator, 7 is a capillary tube for cooling and defrosting which is a flow rate control device, 8 and 9 are check valves, and 51 and 52 are first and second pipes provided in the piping of the outdoor heat exchanger 5 The second temperature sensor 11 is a controller to which the first and second temperature sensors 51 and 52 are connected, has a timer function inside, and outputs a switching signal for heating and defrost operation.

In the above configuration, the operation will be explained. During heating operation, the refrigerant discharged from the compressor 1 is passed through the four-way valve 2,
It passes through the indoor heat exchanger 8, the check valve 8, the heating capillary tube 4, the outdoor heat exchanger 5, the four-way valve 2 again, and is sucked into the compressor 1 via the accumulator 6.

Also, during defrost operation, the four-way valve 2 is switched, and the refrigerant discharged from the compressor 1 is transferred to the four-way valve 2, the outdoor heat exchanger 5,
A circulation cycle is formed in which the air passes through the check valve 9, the cooling and defrosting capillary 7, the indoor heat exchanger 8, and the four-way valve 2 again, and is sucked into the compressor 1 from the accumulator 6.

During heating operation, the nitrogen controller 11 uses an integration timer in the controller 11 to determine the elapsed heating time 1. At the same time, the pipe temperature T detected by the first temperature sensor 51 and the defrost prohibition time t set by the controller 11 are calculated. ! I and defrost start temperature Ts are compared, t + > tos, T +
When < T s, an output is generated to switch to defrost operation, and t + > tos.

When T+>Ts, heating operation is continued.

Further, during the defrost operation, the controller 11 integrates the defrost elapsed time t2 using the integration timer in the controller 511, and also uses the pipe temperature T2 detected by the second temperature sensor 52 and the defrost temperature set by the controller 11. maximum time t
o, , X and the defrost end temperature TE, the second >T.

When t2<TE (D when t2>to-,), an output is generated to switch to heating operation.

Therefore, since the timing of entering defrost from heating operation is determined by the defrost prohibition time and is kept constant, defrost is entered even when the amount of frost formation is extremely small and defrost is unnecessary.

On the other hand, the amount of frost buildup is large and the defrost is not sufficiently performed, and due to the maximum defrost time limit, the defrost ends and heating operation begins with residual frost remaining.

[Problem to be solved by the invention]

Conventional air conditioners are configured as described above, and because the defrost prohibition time is fixed, they unnecessarily enter defrost operation even when the outside temperature is low and the amount of frost formation is small, and conversely, the defrost prohibition time is set constant. If the amount is large, the maximum defrost time will be reached and the defrost will end before the defrost is completely finished, resulting in frost remaining or
The problem of the refrigerant discharge temperature dropping too low, resulting in a very slow start-up during the next heating operation, and a decrease in heating efficiency, was resolved.

This invention was made in order to solve this problem.It defrosts at the optimal timing, speeds up the start-up when restarting heating after defrosting, and efficiently performs heating under low outside temperatures. The purpose is to provide an air conditioner that can perform

[Means to solve the problem]

The air conditioner according to the present invention configured as described above has a compressor, a four-way valve, an indoor heat exchanger, a flow rate control device, an outdoor heat exchanger, and an accumulator connected in sequence to form a refrigerant circulation cycle. In this air conditioner, a switching signal for heating and defrost operation is output by a temperature detection means provided in the piping of the outdoor heat exchanger and a built-in time integration means, and a switching signal for heating and defrost operation is outputted. The temperature detection means detects the discharge pipe temperature during heating operation after the defrost is released, and the time elapsed time for the discharge pipe temperature to reach a predetermined temperature is accumulated by the time integration means, and the length of this time is calculated. The above object is achieved by providing a control means for determining the next defrost prohibition time.

(Function) The air conditioner according to the present invention configured as described above detects the pipe temperature by the temperature detecting means provided in the pipe of the heat exchanger and sends it to the control means, and also calculates the time elapsed heating time. When switching from heating operation to defrost operation, the control means outputs a switching signal based on the piping temperature of the outdoor heat exchanger and the defrost prohibition time. The time elapsed time for the pipe temperature to reach a preset predetermined temperature is integrated by the time integration means, and the defrost prohibition time during the next heating is determined based on the length of this time.

(Example) An example of an air conditioner according to the present invention will be described below based on the drawings.

FIG. 1 is a refrigerant circuit diagram showing the configuration of one embodiment of the same, FIG. 2 is an electric circuit diagram showing the internal configuration of the controller of the air conditioner and its surrounding circuits, and FIG. 3 is the operation of the controller. FIGS. 4 and 5 are electric circuit diagrams showing circuits of other embodiments of the present invention, and flow charts showing operations. In addition, in the figures, the same or corresponding parts are represented by the same reference numerals.

In FIG. 1, numerals 1 to 9 are the same as those in the conventional example, so the details will be omitted.

10 is a temperature sensor which is a temperature detection means provided in the outdoor heat exchanger piping, 12 is a temperature sensor which is also a temperature detection means provided in the discharge pipe, and 11 is a temperature sensor to which the two temperature sensors 10 and 12 are connected. , is equipped with a timer 18 which is a time integration means having a function of integrating the cumulative heating time shown in FIG. 2 and a function of integrating the time until the discharge pipe temperature reaches a predetermined temperature. Prohibited time t. This is a controller that is a control means that sets the defrost start temperature Ts and end temperature T8, and generates a signal to switch between defrost and heating operation. When the defrost signal is generated, the electromagnetic coil 14 of the electromagnetic valve 13 shown in FIG.

In FIG. 2, a controller 11 is a control means equipped with a microcomputer, and signals from an outdoor heat exchanger piping temperature sensor 10 and a discharge piping temperature sensor 12 are input to a circuit 1.
6, central processing unit 17 (hereinafter referred to as CPU)
It is designed to output to .

The controller 11 is also provided with the timer 18, and data is exchanged between the timer 18 and the CPU 17. The output of the CPU 17 is outputted to a relay coil 20 and a semiconductor relay 21 through an output circuit 19.

The relay coil 20 has a contact 22, and this contact 2
2 and the solenoid valve coil 14 are connected in series between both poles of a power source 24. This solenoid valve coil 14 is a relay coil 20
The contact 22 opens and closes in response to energization (energization) 1 and de-energization (deenergization), and is thereby energized or demagnetized.

Further, the semiconductor relay 21 and the fan 23 of the indoor unit are connected in series between the power supply 24. semiconductor relay 21
receives the signal from the output circuit 19 and turns on the fan 2 of the indoor unit.
By changing the energization rate to No. 3, the number of rotations thereof is changed. Furthermore, a primary coil of a transformer 25 is connected between the power sources 24, and the primary coil of the transformer 25 applies voltage to each component circuit section of the controller 11.

In FIG. 3, T is the defrost start temperature, T is the defrost end temperature, tos is the defrost prohibition time, and j
Dmax is the maximum defrost time, Td is the compressor discharge pipe temperature, 1. tRo represents a preset time until the predetermined discharge pipe temperature Td0 is reached.

(motion) The operation will be explained based on the above configuration.

In FIG. 3, when the power supply 24 is input, the controller 11
is each initial setting value TB in step S1.

Tε・tD−... Set tRo・Td・etc. Then, in step S2, the first defrost prohibition time t
Set DSI. Defrost prohibition time from next time t
os is corrected by the controller 11. Next, in step S3, the pipe temperature T1 is detected by the pipe temperature sensor 10 provided on the pipe of the outdoor heat exchanger 5. Further, if the heating operation is being performed in step S4, the elapsed heating time t1 is integrated in step S5, and this integrated time is combined with the set initial defrost prohibition time t. , l are compared in step S6, and the pipe temperature T and the set defrost start temperature Ts are compared in step S7,
When t1≧t0111 and T1≦T8, a defrost switching signal is output, and the integration of the heating time t is completed in step S8. The heating operation is continued under conditions other than these conditions.

On the other hand, if the defrost operation is being performed in step S4, the defrost time Δto is determined in step S9.
is integrated, the outdoor heat exchanger piping temperature T2 is detected in step S10, and the piping temperature T2 is compared with the defrost end temperature TE in step Sll. If T2<T, the defrost time Δ1 is determined in step SIZ. ．． and the longest defrost time j Deaax, and Δ1. ≧tD□8
If so, in step S13, a heating switching signal is output, the integration of the defrost time is finished, and the heating is switched. At the same time, the heating rise time tR is counted in step S14. The discharge pipe temperature Td of the compressor is detected in step S15, and compared with the preset discharge pipe temperature Tdo in step 516. If Td≧Tdo, the integration of the heating rise time tR is stopped in step S17. Next, in step 51B and S19, this t8 is compared with the preset tRo, and when tR>tRo,
Next time t D3 = t D! il-α (step 520
), when tR”tRo, the next tos=tos+
(Step 521), when tR<tRO, next time (7) jos=tos+ +C! (Step 522). However, α is an arbitrarily set correction time, and tDSi is an initially set defrost prohibition time.

As described above, the controller 11 corrects and determines the next defrost prohibition time based on the rate of increase in the temperature of the discharge pipe of the compressor after the defrost is released.

In the embodiment described above, the next defrost prohibition time was determined based on the rising rate of the temperature of the discharge pipe of the compressor, but in other embodiments, as shown in FIGS. 4 and 5, the discharge pipe temperature sensor 12 Instead of indoor heat exchanger piping temperature sensor 1
2' may be used to determine the next defrost prohibition time based on the rate of increase in the pipe temperature of the indoor heat exchanger 3, and the same effects as in the embodiment described above can be achieved.

[Effect of the Invention J As explained above, the temperature detection means provided in the piping of the outdoor heat exchanger and the built-in time integration means) output a switching signal for heating and defrost operation, and
Temperature detection means installed in the discharge pipe of the compressor,
Detects the discharge pipe temperature during heating operation after defrost is released, integrates the time until the discharge pipe temperature reaches a predetermined temperature using a time integration means, and corrects the next defrost prohibition time based on the length of this time. Since the control means is configured to make a decision based on the temperature, it is possible to always perform defrost at the optimal timing, and also to accelerate the start-up of heating when the defrost heating is restarted. The heating efficiency of the air conditioner can be significantly improved.

[Brief explanation of drawings]

FIG. 1 is a refrigerant circuit diagram showing the configuration of an embodiment of the air conditioner of the present invention, FIG. 2 is an electric circuit diagram showing the internal configuration of the controller of the air conditioner and its surrounding circuits, and FIG. The figure also shows a flowchart showing the operation of the controller.
5 and 5 are electric circuit diagrams showing the circuit of the controller of another embodiment of the air conditioner of the present invention and a flowchart showing the operation, and FIG. 6 is a refrigerant circuit diagram showing the conventional example. . 10---Outdoor heat exchanger piping temperature sensor 11・-
-Controller 12--Compressor discharge pipe temperature sensor 18--Timer. In addition, the same or equivalent parts in 5 are represented by the same reference numerals.

Claims (1)

[Claims] In an air conditioner in which a compressor, a four-way valve, an indoor heat exchanger, a flow control device, an outdoor heat exchanger, and an accumulator are connected in sequence to form a refrigerant circulation cycle, The built-in temperature detection means and built-in time integration means output a switching signal for heating and defrost operation, and the temperature detection means installed in the discharge pipe of the compressor outputs a switching signal for heating operation after defrost is released. The apparatus further comprises a control means for detecting the temperature of the discharge pipe, integrating the time required for the temperature of the discharge pipe to reach a predetermined temperature by the time integrating means, and determining the next defrost prohibition time based on the length of this time. An air conditioner featuring: