JPH0730940B2 - Air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an air conditioner having a heat storage tank used as an auxiliary heat source during defrosting operation.

(Prior Art) As a conventional example of the above-mentioned air conditioner, for example, a device described in Japanese Patent Publication No. 62-20460 can be cited.
A refrigerant circuit diagram of the apparatus is shown in FIG. 5, and as shown in the figure, the compressor 51, the four-way switching valve 52, and the first gas pipe 5 are connected.
3, the indoor heat exchanger 54, the liquid pipe 55, the outdoor heat exchanger 56, the second gas pipe 57 are sequentially connected to form a refrigerant circulation circuit, and further, the liquid pipe 55 is interposed therebetween. The first bypass pipe 59, which bypasses the pressure reducing mechanism 58, is
The gas pipes 57 are respectively connected to second bypass pipes 61 that bypass the solenoid valve 60 interposed therebetween. The refrigerants flowing in the bypass pipes 59 and 61 respectively exchange heat with a heat storage agent such as water filled in the heat storage tank 62.

In the above device, the heating operation is performed by circulating the refrigerant discharged from the compressor 51 from the indoor heat exchanger 54 to the outdoor heat exchanger 56 through the pressure reducing mechanism 58, as shown by the solid arrow in the figure. . In addition, the heating heat storage operation is performed by the pressure reducing mechanism.
The solenoid valve 63 installed in front of 58 is closed to
This is done by bypassing the refrigerant to the bypass pipe 59. At this time, as indicated by a broken line arrow in the figure, the pressure of the circulating refrigerant is reduced by the pressure reducing mechanism 64 provided on the rear side of the heat storage tank 62 in the first bypass pipe 59, and the indoor heat exchanger 54 and the heat storage Refrigerant is condensed in the tank 62 and the surplus heating heat amount is stored in the heat storage tank 62.

On the other hand, in the defrosting operation of the outdoor heat exchanger 56, in the above heating cycle, as shown by the one-dot chain line arrow in the figure, the solenoid valve 65 connected in parallel to the pressure reducing mechanism 58 is opened, and the This is done by closing the solenoid valve 60 of the second gas pipe 57 to bypass the refrigerant to the second bypass pipe 61. At this time, the pressure reducing mechanism installed in the second bypass pipe 61.
The circulating refrigerant is decompressed in 66, and therefore, the refrigerant is condensed in the indoor heat exchanger 54 and the outdoor heat exchanger 56 and evaporated in the heat storage tank 62. As a result, the heat storage tank
Simultaneous operation of heating and defrosting with 62 as an auxiliary heat source is performed.

And in the above device, the reference temperature when the amount of heat capable of performing simultaneous operation of heating and defrosting in the heat storage tank 62 is set in advance, when the detected temperature is equal to or lower than the reference temperature, It is designed to lower the heating capacity by lowering the indoor blower fan to a certain number of revolutions and to secure the amount of heat required for defrosting.

(Problems to be solved by the invention) By the way, in the above, for example, when the outside air temperature is low and it is necessary to perform the heating operation with a larger heating capacity, the heating surplus heat amount is reduced, so that the heat storage tank 62 has a sufficient heat amount. Cannot be ensured, and as a result, the defrosting operation in which the heating capacity is lowered is frequently performed, and there is a problem that satisfactory comfort cannot always be obtained.

The present invention has been made in view of the above, and an object thereof is to provide an air conditioner that can secure a heat storage amount required during a defrosting operation, can suppress a decrease in heating capacity as much as possible, and can improve air conditioning comfort. To do.

(Means for Solving the Problems) Therefore, in the air conditioner of the present invention, the evaporator 1 and the condenser 3 are connected to the compressor 1 having a variable compression capacity to form a refrigerant circulation circuit, while the compressor 1 is used. An air conditioner configured to provide a heat storage tank 13 for storing heat dissipated to the outside from the casing, and to add the heat storage amount in the heat storage tank 13 to the circulating refrigerant during the defrosting operation of the evaporator 2. As shown in FIG. 1, a frosting amount detecting means 24 for detecting the frosting amount on the evaporator 2 and a heat storage state detecting means for detecting a heat storage state amount in the heat storage tank 13 as shown in FIG. 23, and a compression field force changing unit 41 that operates by increasing the compression capacity of the compressor 1 when the detected heat storage state amount when the detected frost amount reaches the first reference amount is equal to or less than a set amount, The second amount of detected frost that is larger than the first reference amount
Defrosting operation switching means 42 for switching to the defrosting operation when the reference amount is reached is provided.

(Operation) In the above-described air conditioner, the heat storage tank 13 stores heat dissipated from the casing of the compressor 1 which is in a high temperature state during operation. Then, when the frost attached to the evaporator 2 reaches the first reference amount before switching to the defrosting operation, the compressor 1 according to the heat storage state amount in the heat storage tank 13
Control is performed to increase the compression capacity of the. That is, by the time of switching to the defrosting operation, if it is determined that the required heat storage amount is not reached in the operating state as it is, the compression capacity of the compressor 1 is increased to increase the heat generation amount,
The heat storage rate is increased to control the required amount of heat. Therefore, the defrosting movement is performed in a state in which the required amount of heat storage is secured without lowering the heating capacity, so that it is possible to suppress the decrease in room temperature to a smaller level than in the past and improve air conditioning comfort. .

(Examples) Next, regarding specific examples of the air conditioner of the present invention,
A detailed description will be given with reference to the drawings.

FIG. 2 shows an outdoor unit X having a compressor 1 having a variable compression capacity and an outdoor heat exchanger 2 acting as an evaporator during heating operation and a condenser during cooling operation, and a condenser and cooling operation during heating operation. A refrigerant circuit diagram in a separate type air conditioner configured by connecting an indoor unit A having an indoor heat exchanger 3 that sometimes acts as an evaporator is shown with a control block diagram.

The discharge pipe 4 of the compressor 1 and the suction pipe 6 provided with the accumulator 5 are connected to a four-way switching valve 7, and the four-way switching valve 7 has a first gas pipe 8, The indoor heat exchanger 3, the first liquid pipe 9, the electric expansion valve 10,
The second liquid pipe 11, the outdoor heat exchanger 2, and the second gas pipe 12 are connected to form a refrigerant circulation circuit. On the other hand, the compressor 1
A heat storage tank 13 is wound around the casing of the
Reference numeral 13 is connected to the first liquid pipe 9 by a bypass outward pipe 14 and to the second liquid pipe 11 by a bypass return pipe 15. The heat storage tank 13 is configured by fitting an annular container filled with a heat storage agent such as water or calcium chloride hexahydrate into the compressor 1 and further winding a heat insulating sheet and a soundproof sheet around the outer circumference. Therefore, the heat dissipated from the compressor 1, which is in a high temperature state during operation, to the surroundings is stored in the heat storage agent. And the above-mentioned bypass outward pipe
When the refrigerant circulates from 14 to the bypass return pipe 15 through the inside of the heat storage tank 13, the above-mentioned heat storage amount of heat is given to the circulating refrigerant. An electromagnetic valve 16 is provided in the bypass outward pipe 14. Further, the outdoor heat exchanger 2 is provided with an outdoor fan 21 of a propeller fan type and an indoor heat exchanger 3
A cross-flow fan type indoor fan 22 is attached to each of the above. Further, the heat storage tank 13 has a heat storage tank temperature sensor 23 including a thermistor for detecting the temperature of the heat storage tank 13 as heat storage state detecting means, and the outdoor heat exchanger 2 has frost formation amount detecting means. As this heat exchanger 2
An outdoor heat exchanger temperature sensor 24 for detecting the temperature of each is attached.

In the heating operation in the above device, the four-way switching valve 7 is positioned at the switching position shown by the solid line in the figure, the electromagnetic valve 16 is closed, and the discharge gas refrigerant from the compressor 1 is transferred from the indoor heat exchanger 3 to the electric expansion valve. It is carried out by circulating the heat through 10 to the outdoor heat exchanger 2. At this time, the indoor heat exchanger 3 serves as a condenser,
Further, the outdoor heat exchanger 2 functions as an evaporator, and the heat of condensation heats the room. On the other hand, in the cooling operation, the four-way switching valve 7 is switched to the switching position shown by the broken line in the figure from the above, and the gas refrigerant discharged from the compressor 1 is transferred to the outdoor heat exchanger 2.
From the indoor heat exchanger 3 to the indoor heat exchanger 3.
As an evaporator and the outdoor heat exchanger 2 as a condenser.

Then, in the defrosting operation for removing the frost adhering to and growing on the outdoor heat exchanger 2 during the heating operation, in the refrigerant cycle during the heating operation, the solenoid valve 16 of the bypass outward pipe 14 is further opened, and the outdoor This is done by stopping the fan 21. At this time, the gas refrigerant discharged from the compressor 1 is condensed in the indoor heat exchanger 3, and therefore the indoor heat is continued by the condensation heat released at that time. Then, the heat is circulated in the heat storage tank 13 from the first liquid pipe 9 through the bypass forward pipe 14, and the amount of heat stored in the heat storage tank 13 at this time is given to the circulating refrigerant to cause an increase in the amount of heat retained in the refrigerant, thereby causing a gas phase Becomes a gas-liquid mixed phase having an increased ratio of 1) and flows into the outdoor heat exchanger 2 from the bypass return pipe 15 and the second liquid pipe 11. The inflowing refrigerant temperature at this time is
It is sufficiently higher than the outdoor heat exchanger 2 with frost, and therefore sensible heat based on the temperature difference and latent heat associated with the condensation of gas phase components are applied to the outdoor heat exchanger 2 to progress defrosting. . After that, the outdoor heat exchanger 2 to the accumulator 5
It is returned to the compressor 1 via. The liquid refrigerant separated from the gas phase in the accumulator 5 is sucked into the compressor 1 by an appropriate amount, evaporated inside, and circulated in the above cycle. In this way, in addition to the compression work in the compressor 1, the amount of heat stored in the circulating refrigerant increases due to the cycle in which the amount of heat stored in the heat storage tank 13 is used as a heat source, and as a result, the indoor heating as described above is performed. And defrosting can be performed at the same time.

Next, based on the control block diagram shown in FIG.
For convenience, the operation control during heating will be described.

As shown in the figure, the outdoor unit X is provided with the outdoor control device 31 and the indoor unit A is provided with the indoor control device 32, respectively. When the user turns on the operation switch, the indoor control device 32 emits the light. Depending on the driving start signal
The outdoor control device 31 switches the four-way switching valve 7, starts the compressor 1, controls the opening degree of the electric expansion valve 10, and operates the outdoor fan 21. An indoor fan operation signal is output from the outdoor control device 31 to the indoor control device 32, whereby the indoor fan 22 is operated and heating operation is started. An inverter 33 is provided in the outdoor control device 31 in order to control the rotation speed of the compressor 1, that is, the compression capacity, and further, an inverter 33 is provided according to various input signals described later. An arithmetic circuit 34 for appropriately setting the drive frequency and a drive circuit 35 for operating the frequency inverter 33 at the set frequency are provided.
In the figure, 36 is a power supply circuit, and 37 is a converter for converting a commercial power supply into direct current.

A temperature difference signal between the set room temperature and the detected room temperature is input to the arithmetic circuit 34 from the indoor control device 32. Further, temperature signals detected by the heat storage tank temperature sensor 23 and the outdoor heat exchanger temperature sensor 24 are also input, and the drive frequency of the compressor 1 is generated based on these input signals. First, during steady heating operation, the indoor control device 32
Based on the temperature difference signal from
The PID control sequentially generates a frequency according to the load change on the indoor side and outputs the frequency to the drive circuit 35, whereby the heating operation with the compression capacity corresponding to the indoor load is continued. Therefore, as the room temperature rises as the heating operation continues and the temperature difference from the set room temperature becomes smaller, the control frequency gradually decreases the drive frequency of the compressor 1.

During the heating operation described above, as described above, the amount of heat radiated from the compressor 1 that is operated in a high temperature state is absorbed, and the amount of stored heat gradually increases in the heat storage tank 13. Then, the temperature rises according to the amount of stored heat.

Further, during the heating operation is continued, in the arithmetic circuit 34, monitoring control of the temperature detected by the outdoor heat exchanger temperature sensor 24 is also performed, and the outdoor heat exchange that causes a temperature decrease with an increase in the amount of frost formation. When it is determined that the detected temperature of the device 2 has dropped to the initial temperature state in which frost has formed, that is, the first reference temperature, the arithmetic circuit 34 performs defrosting start pretreatment. This is the third part of this process.
A description will be given based on the control flowchart in the figure.

In the figure, step S1 is a step of monitoring the detected temperature Tb of the outdoor heat exchanger 2 described above, and if it is determined that this Tb has dropped to the first reference temperature T1 described above, then in step S2 The temperature Th detected by the heat storage tank temperature sensor 23 is read. Then, in Step S3, the above Th is compared with the reference heat storage tank temperature TR corresponding to the amount of heat storage required during the defrosting operation, and if Th is lower than TR, in Step S4, as the drive frequency of the compressor 1, A preset high frequency fh is output and the number of revolutions corresponding to the above fh is increased so that the compression work amount in the compressor 1 becomes large.
Next, in step S5, the outdoor heat exchanger temperature Tb has dropped to the second reference temperature T2 that determines that the frost attached to the outdoor heat exchanger 2 has grown and needs to be defrosted. The above operating state is maintained until it is determined, and when Tb reaches T2, the process proceeds to step S6 to start the defrosting operation described above. Note that when Th is equal to or greater than TR in step S3, the above frequency increase control is not performed, and the control according to the load on the indoor side until then is continued.

And the frost attached to the outdoor heat exchanger 2I is removed by the defrosting operation, and when the temperature detected by the outdoor heat exchanger temperature sensor 24 rises to the defrosting completion determination temperature, the defrosting operation is terminated. , Restart heating operation.

As a result of the above control, for example, as shown in the schematic diagram of the temperature change of the heat storage tank in FIG. 4, when the heat storage tank temperature does not reach the reference heat storage tank temperature TR at the start of frost formation (A in the figure), The driving frequency of the compressor 1 is changed so that the amount of heat generated in the compressor 1, that is, the amount of heat stored per hour in the heat storage tank 13 increases, and the temperature of the heat storage tank rises faster. As a result, at the start of the defrosting operation, the temperature of the heat storage tank reaches the reference temperature TR, so that the amount of heat storage required during the defrosting operation is secured. Therefore, as in the conventional example shown by the broken line in the figure, compared with the case where the defrosting operation is performed while the heat storage amount is insufficient and the heating capacity is significantly reduced, the heating capacity is hardly reduced in the above. A defrosting operation that does not occur is performed, and a comfortable air conditioning state can be maintained. Moreover, in the above, while being the structure which accumulate | stores the exhaust heat from the compressor 1,
Since the increase in the compression capacity is controlled by checking the frosting state before the defrosting operation starts, for example, in the case of the control based on the outside temperature, it occurs under the non-frosting condition when the outside temperature is low and the humidity is low. Since it prevents malfunctions and does not cause unnecessary changes, it is also a highly economical device.

In the above embodiment, the compression capacity changing means 41 is configured in steps S3 and S4 in FIG. 3, and the defrosting operation switching means 42 is configured in step S5, but other configurations having the same function are used. be able to. Further, in the above description, an example in which the operating state is maintained until the defrosting operation starts after changing the compression capacity has been described, but for example, a configuration in which a timer is provided to continue for a predetermined time or the heat storage tank temperature has risen to the reference temperature. It is also possible to adopt a configuration in which it is determined that the above-mentioned change operation is terminated.

(Effects of the Invention) As described above, in the air conditioner of the present invention, the heat storage tank for storing the heat dissipated from the casing of the compressor, which is in a high temperature state during operation, remains unchanged during switching to the defrosting operation. When it is determined that the required amount of heat storage is not reached in the operating state, control is performed in advance to increase the compression capacity of the compressor to increase the amount of heat generation and increase the heat storage rate.
The defrosting operation will be performed in a state in which the required amount of heat storage is secured without lowering the heating capacity, and as a result, it is possible to suppress the decrease in room temperature to a level smaller than before and improve air conditioning comfort. To do.

[Brief description of drawings]

FIG. 1 is a functional block diagram of the present invention, FIG. 2 is a refrigerant circuit diagram additionally showing a control block diagram of an air conditioner configured by applying the present invention, and FIG. 3 is a removal block diagram of the air conditioner. FIG. 4 is a schematic diagram showing an example of changes in the heat storage tank temperature, the heating capacity, and the rotation speed of the compressor in the air conditioner, and FIG. 5 is a refrigerant circuit diagram of a conventional device. is there. 1 ... Compressor, 2 ... Outdoor heat exchanger (evaporator), 3 ...
Indoor heat exchanger (condenser), 13 ... Heat storage tank, 23 ... Heat storage tank temperature sensor (heat storage state detection means), 24 ... Outdoor heat exchanger temperature sensor (frost formation amount detection means), 41 ... Compression Capacity changing means, 42 ... Defrosting operation switching means.

Claims (1)

[Claims] 1. A compressor (1) having a variable compression capacity is connected to an evaporator (2) and a condenser (3) to form a refrigerant circulation circuit, and the outside of the compressor (1) from a casing. A heat storage tank (13) for storing the heat dissipated to the other side is provided, and air is configured to give the heat storage amount in the heat storage tank (13) to the circulating refrigerant during the defrosting operation of the evaporator (2). A harmony machine, further comprising a frosting amount detecting means (24) for detecting the frosting amount on the evaporator (2), and a heat storage state detecting means (for detecting a heat storage state amount in the heat storage tank (13) ( 23) and a compression capacity changing means for increasing the compression capacity of the compressor (1) to operate when the detected heat storage state quantity when the detected frost formation quantity reaches the first reference quantity is equal to or less than a set quantity ( 41), and the detected frost formation amount is above the first
An air conditioner comprising: a defrosting operation switching means (42) for switching to a defrosting operation when a second reference amount larger than the reference amount is reached.