JPH03199848A - Fan controller of heat accumulation type air conditioner - Google Patents

Abstract

PURPOSE:To perform an optimum defrosting operation taking a heating capacity into consideration by reducing the number of revolutions of an indoor unit fan when the gradient of a condensation temperature or of a temperature related to it is judged to be negative for a prescribed time by temperature gradient judging means. CONSTITUTION:When an evaporation temperature in an indoor heat exchanger 25 reaches a temperature indicative of frosting at a time point A, a defrost signal becomes 'on' and a defrosting operation is initiated. Since, when the quantity of frost is large at this time, frost is head to melt, a condensation temperature Tc keeps substantially the same value as shown by a solid line. When heat accumulated in a heat accumulating material begins to be lost at a time point B, frost stops to melt, the temperature of a refrigerant returning to a compressor 21 falls accompanied by a fall in a discharged refrigerant refrigerant temperature and a condensation temperature gradient becomes negative. When this condition continues for a time ts, the an tap of an indoor unit fan 39 is set to 'off' at a time point C. Thus, the quantity of heat required for defrosting is secured by reducing a room heating capacity. When frost begins to melt and the condensation temperature begins to rise, the fan tap is returned to 'H'.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a heat storage device that controls the rotational speed of an indoor unit fan during defrosting by a regenerative air conditioner that defrosts using heat accumulated in a heat storage device. The present invention relates to a fan control device for a type air conditioner.

<Prior Art> Conventionally, as a fan control device for defrosting in a regenerative air conditioner, there is a device as shown in FIG. 4 (Japanese Unexamined Patent Publication No. 01-111149). In FIG. 4, compressor 1. Four-way valve 2. Outdoor heat exchanger 3. Throttle means that can be opened and closed 4. The indoor heat exchanger 5 and the accumulator 6 are connected in sequence to form a refrigerant circuit. Furthermore, a cylindrical regenerative heat exchanger 7 is provided on the outer periphery of the compressor I. When the compressor 1 is in operation, the heat is stored in the heat storage material 8 via the device heat storage heat exchanger 7 constituted by the compressor 1.

When the outdoor heat exchanger 3 is frosted during heating in the regenerative air conditioner, a defrost operation is executed as follows. That is, by closing the throttle means 4 and opening the electromagnetic on-off valve 10, the flow of refrigerant is controlled between the compressor 1, the four-way valve 2, and the four-way valve 2. Indoor heat exchanger5. Solenoid on-off valve 10.
A refrigerant passage 11 provided between the regenerative heat exchanger 7 and the compressor 1. Compressor 1 via outdoor heat exchanger 3 and four-way valve 2
change to return to . At that time, the refrigerant passes through the refrigerant passage It
When passing through the outdoor heat exchanger 7, the heat stored in the heat storage material 8 is received and taken, and when passing through the outdoor heat exchanger 3, it is released to perform defrosting.

When the defrost operation is being executed as described above, if the blowout temperature in the indoor unit detected by the hot water temperature sensor 12 is lower than the predetermined temperature even after a predetermined period of time has passed since the defrost operation was started, the micro In order to achieve the above objective, the computer 9 still defrosts the defrost when supplying the heat stored in the heat storage device to the outdoor heat exchanger 25 as illustrated in FIG. In a fan control device for a regenerative air conditioner that detects a decrease in the amount of heat stored in a heat storage device and controls the rotation speed of an indoor unit fan 39, the condensation temperature of the indoor heat exchanger 23 or a temperature related thereto is detected. a temperature sensor 27 for calculating the condensation temperature detected by the temperature sensor 27 or a temperature gradient related thereto; and a temperature gradient calculation means for calculating the condensation temperature detected by the temperature sensor 27 or a temperature gradient related thereto; temperature gradient determining means for determining whether or not is negative for a predetermined period of time; The present invention is characterized in that it includes a fan control means for reducing the number of rotations of the fan 39.

<Operation> During the defrost operation, it is determined that the indoor heat exchanger 230 has not finished its operation. Then, the rotation speed of the fan 13 of the indoor unit is lowered to perform the defrost operation preferentially.

<Problems to be Solved by the Invention> As described above, in the conventional fan control device, the rotation speed of the fan 13 of the indoor unit is reduced based on the absolute value of the blowing temperature in the indoor unit.

Therefore, when the blowout temperature drops to a predetermined temperature, the heat stored in the heat storage material 8 may have already been used up. In such a case, there is a problem that even if the rotation speed of the fan 13 is lowered, it is not enough, and the frost attached to the outdoor heat exchanger 3 remains unmelted.

Therefore, the purpose of this invention is to predict the amount of heat storage in relation to changes in condensing temperature and control the rotation speed of the fan of the indoor unit, thereby achieving an optimal defrost operation that takes into account both heating capacity and defrost. An object of the present invention is to provide a fan control device for a regenerative air conditioner that can be implemented.

<Means for Solving the Problem> The condensation temperature or a temperature related thereto is detected by the temperature sensor 27.
When detected by the temperature sensor 27, the condensation temperature detected by the temperature sensor 27 or the temperature gradient related thereto is calculated by the temperature gradient calculation means. When the temperature gradient determination means determines that the condensation temperature calculated by the temperature gradient calculation means or the temperature gradient related thereto is negative for a predetermined period of time, the fan control means controls the rotation speed of the indoor unit fan 39. is reduced.

That is, the rotation speed of the indoor unit fan 39 is reduced not after the condensing temperature has decreased to a predetermined value, but when the condensing temperature begins to decrease.

<Embodiment> This invention focuses on the fact that when the heat stored in the heat storage device becomes insufficient during defrosting, the gradient of the condensation temperature in the indoor heat exchanger becomes negative, and the gradient of the condensation temperature is set to a predetermined value. This reduces the rotation speed of the indoor unit fan when the time becomes negative.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a refrigerant circuit diagram according to the present invention, which is almost the same as the refrigerant circuit diagram in the conventional example described above.

In FIG. 1, compressor 21. Four-way valve 22. Indoor heat exchanger 23. A main refrigerant circuit is formed by sequentially connecting an electric valve 24, which is a throttle means, which can be opened and closed, an outdoor heat exchanger 25, and an accumulator 26 in an annular manner.

A substantially cylindrical regenerative heat exchanger 3 is provided on the outer periphery of the compressor 2I.
Set 0. This regenerative heat exchanger 30 has one end connected to the compressor 2.
1, and a refrigerant passage 29 that passes through the fins 31 and spirals around the compressor 21. In this way, the periphery of the regenerative heat exchanger 30 provided around the compressor 2I is further covered with the cylindrical heat storage case 35, and the compressor 21 and the regenerative heat exchanger 30 are sealed. And heat storage case 35
Inside, a temperature sensor 28 is installed near the polyethylene glycol or para-outdoor heat exchanger 25 to detect the evaporation temperature during heating in order to detect frost formation. Additionally, compression $
A temperature sensor 33 for detecting the temperature of the discharge pipe is installed in the discharge pipe 21. And each temperature sensor 27, 28 .
In accordance with commands from the microcomputer 41 based on the detected temperature 33, a defrost operation and control of the rotation speed of the indoor unit fan 39, which will be described in detail later, are performed.

During heating operation, the refrigerant circuit switches the four-way valve 22 to a solid line display and supplies the high-temperature gas refrigerant discharged from the compressor 21 to the indoor heat exchanger 23 via the four-way valve 22. The room is heated by the heat of condensation when the high-temperature, high-pressure refrigerant condenses. The liquid refrigerant condensed by the indoor heat exchanger 23 is then depressurized by the opened electric valve 24 and supplied to the outdoor heat exchanger 25. The refrigerant supplied to the outdoor heat exchanger 25 is evaporated, circulates through the four-way valve 22 and the accumulator 26, and returns to the compressor 21.

During such heating operation, the heat storage material 32 consisting of the temperature sensor 2 fins and the like is filled. Therefore, compressor 2
Heat released from the compressor 21 during operation 1 can be stored in the heat storage material 32 via the heat storage heat exchanger 30. On the other hand, during heat radiation, heat exchange between the refrigerant flowing in the refrigerant passage 29 and the stored heat storage material 32 is performed by the storage heat exchanger 30 independently of the compression of the refrigerant, and a heated high-temperature gas refrigerant is obtained. At this time, since the amount of heat released from the heat storage material 32 per unit time is determined by the difference between the temperature of the heat storage material 32 and the temperature of the refrigerant, the heat stored in the heat storage material 32 can be efficiently extracted by the refrigerant.

For example, at the lower end of the refrigerant passage 29 provided in the storage heat exchanger 30, the indoor heat exchanger 23 and the electric valve 24 are connected by a refrigerant pipe 36 with an electromagnetic on-off valve 34 interposed therebetween. on the other hand,
For example, at the upper end of the refrigerant passage 29, the outdoor heat exchanger 25 and the electric valve 24 are connected by a refrigerant pipe 38 having a check valve 37 that allows refrigerant to flow only in the direction of the arrow.

A temperature sensor 27 is installed near the indoor heat exchanger 23 to detect the condensation temperature during heating, and the microcomputer 41 detects frost formation on the outdoor heat exchanger 25 based on the temperature signal from 8. When detecting this, the microcomputer 41 starts the following defrosting operation.

Hereinafter, the defrost operation executed by the microcomputer 41 will be explained according to the defrost operation flowchart in FIG. 2 and FIG. 1 above.

In step S1, when the temperature detected by the temperature sensor 28 reaches a set temperature indicating that the outdoor heat exchanger 25 has frosted,
The defrost signal is set to "on". Then, based on this defrost signal, the electric valve 24 is closed and at the same time the electromagnetic on-off valve 34 is opened to start the defrost operation.

That is, the liquid refrigerant after being condensed in the indoor heat exchanger 23 is
Since the electric valve 24 is closed, the refrigerant passes through the electromagnetic on-off valve 34 and is supplied to one end of the refrigerant passage 29 provided in the thermal storage heat exchanger 30 via the refrigerant pipe 36 . When this refrigerant flows within the refrigerant passage 29 toward the other end of the refrigerant passage 29, it exchanges heat with the heat storage material 32 by the thermal storage heat exchanger 30 as described above, and is heated and evaporated. The high-temperature gas refrigerant obtained by evaporation is supplied to the outdoor heat exchanger 25 via the refrigerant pipe 38 and the check valve 37 . The supplied gas refrigerant is then condensed in the outdoor heat exchanger 25.

At this time, the heat of condensation is released to remove frost adhering to the outdoor heat exchanger 25. In this way, the partially liquefied refrigerant is returned to the suction side of the compressor 21 via the four-way valve 22 and the accumulator 26.

In this way, heat exchange between the heat storage material 32 and the refrigerant is performed by the compressor 2.
Since the compression is performed independently of the refrigerant compression in step 1, the room is heated with the high temperature gas refrigerant discharged from the compressor 21, while defrosting is performed with the high temperature gas refrigerant that has undergone heat exchange with the heat storage material 32 in the thermal storage heat exchanger 30. It can be carried out. Therefore, the defrost operation can be performed while heating the room without reducing the heating capacity.

In step S2, based on the discharge pipe temperature (i.e., discharge refrigerant temperature) detected by the temperature sensor 33,
The condensation temperature Tc in the indoor heat exchanger 23 is detected based on the fan control signal from the fan motor No. 401.

In step S6, the gradient of the variation in the condensing temperature Tc is calculated based on the condensing temperature Tc detected in step S3 and the condensing temperature Tc detected in step S5.

In step S7, it is determined whether the slope of the condensation temperature Tc calculated in step S6 is negative. If the result is negative, the process proceeds to step S8; if not, the process returns to step S2, where the fan tap setting of the indoor unit fan 39, determination of the end of defrost, and calculation of the condensing temperature gradient are performed again.

In step S8, it is determined whether a time ts has elapsed since the condensation temperature gradient became negative. As a result, if the time ts has not elapsed, the process returns to step S7, and if not, it is determined that the amount of heat stored in the heat storage material 32 has begun to decrease, and the process proceeds to step S9.

In step S9, a fan control signal is output to the fan motor. When the discharge pipe temperature is higher than a predetermined temperature, the fan tap of the indoor unit fan 39 is set to "
The "H" tap is set, while the "L" tap for low speed rotation is set when the temperature is lower than the predetermined temperature.

In this way, when the temperature of the discharged refrigerant is low, the amount of heat stored in the heat storage material 32 is small, so more heat is sent to defrost at the expense of room heating.

In step S3, the condensation temperature Tc in the indoor heat exchanger 23 is detected based on the temperature signal from the temperature sensor 27.

In step S4, it is determined whether the value of the condensing temperature Tc detected in step S3 has reached or exceeded a predetermined temperature "T" indicating the end of defrosting. As a result, the predetermined temperature “
If the temperature is higher than "T", it is assumed that the frost attached to the outdoor heat exchanger 25 has been completely melted, and the process proceeds to step S13. On the other hand, if the temperature is lower than the predetermined temperature "T", the process proceeds to step S5.

In step S5, the temperature signal +2 from the temperature sensor 27 is outputted to the controller 40, and the rotation speed of the indoor unit fan 39 is set to the lowest speed or fan tap that is stopped.

That is, when the amount of heat accumulated in the heat storage material 32 begins to decrease, the indoor unit fan 39 is reduced in rotation speed or stopped, thereby reducing the indoor heating capacity and securing the amount of heat necessary for defrosting. be.

In step S10, the condensation temperature Tc in the indoor heat exchanger 23 is detected based on the temperature signal from the temperature sensor 27.

At step SL+, the value of the condensing temperature Tc detected at step SIO is set to a predetermined temperature "T" representing the end of defrosting.
As a result, if the temperature is higher than the predetermined temperature "T", it is assumed that the frost attached to the outdoor heat exchanger 25 has completely melted and the process proceeds to step S13. On the other hand, if the temperature is higher than the predetermined temperature "T" If it is lower, the process advances to step S12.

In step S12, a time t has elapsed since the start of the defrost operation.
It is determined whether or not d has elapsed. As a result, if the time Cd has elapsed, the process advances to step S13, and if not, the process returns to step SIO.

In step SI3, the defrost signal is set to "off", the defrost operation is ended, and normal operation is started.

FIG. 3 shows the terminus when the defrost operation is performed according to the flowchart of FIG. 2. Third
FIG. 3(a) shows the condensing temperature Tc in the indoor heat exchanger 23, FIG. 3(b) shows the contents of the fan tap of the indoor unit fan 39, and FIG. 3(c) shows the contents of the defrost signal. .

At time A, the evaporation temperature in the outdoor heat exchanger 25 reaches a temperature representing frost formation, the defrost signal is turned "on", and the defrost operation is started. At this time, the fan tap of the indoor unit fan 39 is switched from "H" to "17" based on the discharge pipe temperature in a double manner. When the defrost operation is started in this manner, the condensing temperature Tc, which has once decreased due to frost formation, rises slightly. After that, the temperature remains approximately the same until the frost completely melts. Therefore, when state 5 continues for a time ts, the fan tap of the indoor unit fan 39 is set to "off" at time C. In this way, the indoor heating capacity is reduced to ensure the amount of heat required for defrosting. As a result, the frost starts to melt again and the condensation temperature Tc starts to rise.

In this way, when the preset defrost time td has elapsed, the defrost signal is turned off and the defrost operation is forcibly terminated. And the fan tap is H”
will be returned to.

As described above, in this embodiment, when the condensation temperature gradient based on the temperature signal from the temperature sensor 27 becomes negative for a predetermined time ts, it is determined that the heat accumulated in the heat storage material 32 has begun to disappear.

Then, the rotation speed of the indoor unit fan 39 is set to the lowest speed or the stopped fan tap. Therefore, before the heat accumulated in the heat storage material 32 decreases to the point where it cannot contribute to defrosting, the indoor unit fan
9 can be controlled, the little remaining heat accumulated in the heat storage material 32 is defrosted, the condensation temperature gradient does not become negative, and the fan tap of the indoor unit fan 39 remains at L".

In this state, when the frost attached to the outdoor heat exchanger 25 completely melts, the evaporation temperature in the outdoor heat exchanger 25 rises, and as a result, the condensation temperature T increases as shown by the dotted line (A).
c rises and the fan tap is held at "L". Then, at time D", when the evaporation temperature reaches the temperature "T" indicating the end of defrost, the defrost signal turns "off" and the defrost operation ends. Then, the fan tap turns "H".
” will be returned to.

On the other hand, when there is a large amount of frost, the frost does not melt completely, so the condensation temperature Tc is maintained at approximately the same temperature as shown by the solid line. Then, at time B, when the heat stored in the heat storage material 32 begins to disappear, the frost stops melting and the temperature of the refrigerant returning to the compressor 21 decreases. Then, the discharge refrigerant temperature also decreases and the condensing temperature gradient becomes negative. This can be used effectively only when the condensation temperature gradient is negative to completely defrost.

In the above embodiment, the temperature sensor 27 is installed near the indoor heat exchanger 23 to detect the condensing temperature, but it is installed downstream of the indoor unit fan 39 to detect the temperature related to the condensing temperature. It may also be detected.

In the embodiment described above, a heat storage device including a heat storage heat exchanger 30 and a heat storage material 32 is provided around the compressor 21. However, the present invention is not limited to this, and may be provided separately from the compressor 21 and heat may be stored by other means.

The defrost operation algorithm in the present invention is not limited to the above embodiment.

<Effects of the Invention> As is clear from the above, the fan control device for a regenerative air conditioner of the present invention calculates the temperature gradient from the condensation temperature in the indoor heat exchanger detected by the temperature sensor or the gradient of the temperature related thereto. and when the temperature gradient determination means determines that the calculated condensation temperature or the temperature gradient related thereto is negative for a predetermined period of time, the fan control means is configured to reduce the rotation speed of the indoor unit fan. Therefore, when the condensing temperature starts to drop, the rotation speed of the indoor unit fan can be lowered.

Therefore, according to the present invention, the rotation speed of the indoor unit fan can be appropriately controlled according to the amount of heat storage, and an optimal defrost operation can be performed to complete the defrost while maintaining the heating capacity within the possible range.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of a refrigerant circuit related to a fan control device for a regenerative air conditioner according to the present invention, FIG. 2 is a flowchart of a defrost operation, and FIG. 3 is a defrost operation based on the flowchart of FIG. 2. Time chart,
FIG. 4 is a refrigerant circuit diagram of a conventional fan control device for a regenerative air conditioner. 21...Compressor, 23...Indoor heat exchanger, 2
4. Electric valve, 25. Outdoor heat exchanger, 27.
28... Temperature sensor, 29... Refrigerant passage, 30
...Thermal storage heat exchanger, 32...Thermal storage material, 34...
Solenoid on/off valve, 39... Indoor unit fan, 41...
microcomputer. Patent applicant Agent: Daikin Industries, Ltd.
Patent attorney Aoyama Aoyama and 1 other person Unexamined Patent Publication No. 3 199848 (7)

Claims (1)

[Claims] (1) When defrosting is performed by supplying the heat stored in the heat storage device to the outdoor heat exchanger (25), a decrease in the amount of heat stored in the heat storage device is detected and the indoor unit fan (
39) in a fan control device for a regenerative air conditioner that controls the rotation speed of a regenerative air conditioner, comprising: a temperature sensor (27) that detects the condensation temperature of the indoor heat exchanger (23) or a temperature related thereto; and the temperature sensor (27). temperature gradient calculation means for calculating the gradient of the condensation temperature detected by the temperature gradient calculation means or the temperature gradient related thereto; a temperature gradient determining means for determining, and reducing the rotation speed of the indoor unit fan (39) when the temperature gradient determining means determines that the condensing temperature or the temperature gradient related thereto is negative for the predetermined period of time; A fan control device for a regenerative air conditioner, characterized by comprising fan control means.