JPS62217038A - Air conditioner - Google Patents

Abstract

PURPOSE:To make it possible to perform a dehumidifying operation without any fault under low-temperature environments with a high efficiency and to practice dehu midification while suppressing the lowering of the room temperature by preventing a vaporizer at the time of operating the air conditioner in a dehumidifying mode utilizing a freezing cycle. CONSTITUTION:A bypass circuit 6 which bypasses a condenser 2 and a pressure reduc ing turn-down mechanism 3 to connect an outer side pipeline 1a of a compressor 1 to an inlet side pipeline 4a of a vaporizer 4 is provided in a coolant circuit. A switching valve 7 keeping its closed state during the space cooling mode operation, is disposed in the bypass circuit 6. Further, the air conditioning control system comprises timing means 18 for setting the period of a dehumidifying mode during the dehumidifying mode operation; timing means 19 for ON/OFF controlling the com pressor 1 in every period of the dehumidifying mode; timing means 20 for starting the operation of a blower 5 with a preset time lag after starting the operation of the compressor; timing means 21 for stopping the operation of the blower before the stoppage of the operation of the compressor; and timing means 22 for controlling to open the switching valve 7 of the circuit 6 in a period from the time of stopping the operation of the blower to the time of starting the resumptive operation at the time of the dehumidifying mode operation of the compressor.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an air conditioner, and more particularly to an air conditioner with a dehumidification function that operates in a dehumidification mode using on-off control of a refrigeration cycle. be.

[Conventional technology]

Conventional air conditioners include, for example, Japanese Patent Application Laid-open No. 57-37644.
As shown in the above publication, there is an air conditioner that performs dehumidification while suppressing a decrease in indoor temperature by intermittently performing on-off control of a compressor used in the refrigeration cycle of an air conditioner and an indoor blower. This type of air conditioner dehumidifies air by intermittently driving the compressor to activate the evaporator during dehumidification mode, and then returning the dehumidified and cooled air that has passed through the evaporator to the room using a blower. This has the advantage that the manufacturing cost of the air conditioner can be reduced because dehumidification can be performed using the existing cooling refrigeration cycle without using a dedicated dehumidifier such as a reheater.

[Problem that the invention seeks to solve]

However, this type of dehumidification method has the following points that need to be improved since the moisture in the air passing through the evaporator is attached to the surface of the evaporator to perform dehumidification.

In other words, the surface temperature of the evaporator during the refrigeration cycle is usually about 15°C lower than room temperature, so if the dehumidification mode is operated in a low-temperature environment where the room temperature is about 15°C or lower, the surface temperature of the evaporator will drop. As a result, frost grows on the surface of the evaporator over time, reducing the dehumidifying function.
Furthermore, when switching to blowing operation in this state, the air passing through the evaporator is returned indoors containing frost moisture, making it impossible to achieve a sufficient dehumidifying effect in a low-temperature environment.

The present invention has been made in view of the above points, and its purpose is to provide efficient dehumidification without any trouble even in low-temperature environments while utilizing the on-off control of the existing cooling refrigeration cycle. It is an object of the present invention to provide an air conditioner that can be operated and can perform dehumidification while suppressing a decrease in room temperature.

[Means for solving problems]

In order to achieve the above object, the present invention bypasses the condenser and the vacuum throttling mechanism in the refrigerant circuit of an air conditioner consisting of a refrigeration cycle system, a blower, and an air conditioning control system, and connects the outlet side piping of the compressor and the evaporator. A refrigerant bypass circuit is provided to connect the refrigerant bypass circuit to the inlet side pipe of the refrigerant bypass circuit, and the refrigerant bypass circuit is provided with an on-off valve that maintains a closed valve-like layer during the cooling mode. a first timer for setting a cycle of the dehumidification mode; a second timer for controlling the operation of the compressor by on/off control for each cycle of the dehumidification mode; a third timer for starting the blower at a later time than the compressor; a fourth timer for stopping the blower before stopping the compressor; and fifth time limit means for controlling the opening/closing valve of the refrigerant bypass circuit until the re-start of operation in the dehumidification mode.

[Effect]

According to the present invention having such a configuration, in the cooling mode, the on-off valve of the refrigerant bypass circuit is closed, so the refrigerant does not flow through the bypass circuit, and the compressor, condenser, evaporator, and pressure reducing throttle mechanism It is possible to perform cooling operation by flowing through the path (refrigerant circuit).

Further, in the dehumidification mode, the first timer of the air conditioning control system sets the period of the dehumidification mode, the second timer causes the compressor to operate intermittently at each cycle, and the third and fourth timer This compressor because the blower is driven within the operating time of the compressor.

By intermittent operation of the blower, the air that passes through the evaporator through the same route in the cooling mode is cooled and dehumidified in each dehumidification mode cycle, and then returned indoors, making it possible to perform dehumidification while suppressing a drop in indoor temperature.

Furthermore, when the blower is periodically turned off in the dehumidification mode, the fifth timer operates the on-off valve of the refrigerant bypass circuit between when the blower stops operating and when the compressor starts operating again. Because it controls opening.

Until the compressor stops operating, high-pressure, high-temperature refrigerant flows from the compressor side through this refrigerant bypass circuit and flows into the evaporator. Furthermore, even after the compressor stops operating, the refrigerant bypass circuit remains open until the compressor starts operating again in dehumidification mode, so the high temperature refrigerant in the condenser passes through the refrigerant bypass circuit to the evaporator. flows into. Therefore, these high-temperature refrigerants periodically flow into the evaporator during the dehumidification mode, and can remove frost adhering to the evaporator, making it possible to perform cooling and dehumidification in a frost-free state. Also a compressor.

In addition to intermittent operation of the blower, high-temperature refrigerant is periodically flowed into the evaporator, so even if dehumidifying operation is performed in a low-temperature environment, a drop in room temperature can be suppressed.

〔Example〕

An embodiment of the present invention will be explained based on FIGS. 1 to 5.

FIG. 1 is a refrigeration cycle system diagram of an air conditioner according to an embodiment of the present invention. In the figure, 1 is a refrigerant compressor, 2 is a condenser, 3 is a decompression throttling mechanism, and 4 is an evaporator. In the cooling mode, compressor 1. Condenser 2, pressure reduction throttle mechanism 3, evaporator 4
The refrigerant flows through the path. Reference numeral 5 denotes an indoor fan that sends air passing through the evaporator 4 to the indoor side.

Reference numeral 6 denotes a refrigerant bypass circuit that bypasses the condenser 2 and the pressure reducing throttle mechanism 3 and connects the outlet side plumber a of the compressor 1 and the inlet side pipe 4a of the evaporator 4.

An on-off valve 7 is installed in the refrigerant bypass circuit 6. The on-off valve 7 is kept closed during the cooling operation mode by an air conditioning control system, which will be described later, and is controlled to open and close intermittently based on a predetermined pattern during the dehumidification mode.

Figures 3 (a) and (b) show the control system of the air conditioner. In Figure 3 (a), 8 is a room temperature sensor, and 9 is a sensor that converts the detected value of the room temperature sensor 8 into an analog-digital signal. 10 is a set temperature input switch, 11 is a main operation switch, 12 is an air conditioning control means for controlling air conditioning such as cooling operation and dehumidification operation, and 13 is a compression Relay coil 14a for driving the motor of machine 1, relay coil 16a for driving the motor of blower 5
, is a driving means for turning on and off the relay coil 15a for the driving electromagnetic coil of the on-off valve 7.

14b to 16b are relay contacts of the relay coils 14a to L6a.

The air conditioning control means 12 is composed of one microcomputer, and in the cooling operation mode, it causes the blower 5 to operate at all times, and causes the compressor 1 to operate when the detected value of the room temperature sensor 8 is higher than the set temperature. , it is set to output a control signal that always closes the on-off valve 7 of the bypass circuit 6. Further, the air conditioning control means 12 has built-in time limit means 18 to 23 (see FIG. 4) that operate in the dehumidifying operation mode. FIG. 4 shows a functional block diagram of the air conditioning control means 12 in the dehumidifying operation mode. As shown in the figure, the air conditioning control means 12 has a set temperature input means (
The temperature determination means 17 compares and determines the set temperature value of the switch 10 and the detected value of the room temperature sensor 8 to determine whether the room temperature is higher or lower than the set temperature. When the temperature determining means 17 determines that the room temperature is higher than the set temperature,
As shown in the signal waveform diagram shown in FIG. 2, the first time limit means 18 sets a time limit 1 for one cycle of the repeat mode of the dehumidifying operation.
is set, and when the time limit t1 is set, the second time limit means 1
9 outputs an output signal to operate the compressor 1 within the range of time limit t2, and when the compressor 1 starts, the third time limit means 2
0 outputs an output signal that starts the blower 5 with a delay of the upper time limit 〇, and the fourth time limit means 2.1 outputs an output signal that starts the blower 5 within a time limit t3 shorter than the operating time of the compressor 1. When the signal is output and the blower 5 is further stopped, the fifth timer 22 closes the on-off valve 7 for a period from when the blower 5 stops operating to when the compressor 1 starts operating again (time limit t).
7+tB) is set to open control. Further, when the temperature determination means 17 determines that the room temperature is lower than the set temperature, the dehumidification mode is stopped, but in this case, the sixth
The timer means 23 forces the second timer means 19 to the fifth timer means 2 after the time limit tδ at which the dehumidification mode is stopped.
In this case, a series of operations approximately equal to those up to 2 are temporarily performed.

Next, the operation of this embodiment will be explained.

In the cooling operation mode, the blower 5 is constantly operated, and the compressor 1 has a room temperature sensor 8 indicating the set temperature (set temperature switch 10
It operates when a temperature value higher than the set value of the compressor 1. Condenser 2, throttling mechanism 3. It flows through the path of the evaporator 4 to activate the refrigeration cycle and perform cooling operation.

In the dehumidifying operation mode, the following operations are performed. This operation will be explained with reference to the flowchart in FIG.

Step 1: Room temperature sensor 8. When the temperature determining means 17 determines that the room temperature is higher than the set temperature, first the cycle of the dehumidifying operation mode set by the first timer 18 (
Time limit 1. ) starts, and at the same time, the time limit tz of the second time limit means 19 starts, and the compressor 1 is turned on and starts operating. Further, the third time limit means 2o starts the time limit ts,
Starting of the blower 5 is controlled to be delayed. Therefore, in these processes, only the compressor 1 operates and the on-off valve 7 of the refrigerant bypass circuit 6 is in the closed state, so the refrigerant flows in the same manner as in the cooling operation mode, and the compressor 1. It flows into the evaporator 4 via the condenser 2 and the throttle mechanism 3.

Step 2: When the delay time limit 8 ends, the third time limit means 20 issues an output signal to start the blower 5 (on the blower relay 16a), and the blower 5 starts with the start of the time limit t8. In this case, the blower 5 is started later than the compressor 1 by the time period ts, and during this time the surface temperature of the evaporator 4 is lower than the dew point temperature of the indoor air, so the blower 5 starts operating. At the same time, indoor air can be sufficiently dehumidified by the cooling action of the evaporator 4 before being sent indoors.

Step 3: If the room temperature remains higher than the set temperature after step 2, after the operating time t3 of the blower 5 ends, the fourth timer 21 turns on the blower 5 for the time t7. The compressor 1 is stopped earlier than the end of the operating time t2.

Then, at the same time as the blower 5 stops operating, the opening/closing valve 7 is controlled to open by the fifth timer 22 from the time when the blower 5 stops operating until the compressor 1 starts operating again (time limit t7 and time limit t2I). Ru. At this time, during the time period t7, that is, from the time when the blower 5 stops operating until the compressor 1 stops operating, the high-temperature refrigerant that has been made high-pressure in the compressor 1 due to the operation of the compressor 1 passes through the refrigerant bypass circuit 6. and flows into the evaporator 4.

In addition, since the on-off valve 7 is kept open for the time period t5 (from the stop of the compressor 1 to the restart of the compressor 1) by the fifth time limit means 22 even after the compressor 1 is stopped, in this case, the condenser The high temperature condensed refrigerant in 2 flows into the evaporator 4 through the refrigerant bypass circuit 6. Therefore, from the time when the blower 5 stops, the compressor 1
During the period until the restart of operation (while the evaporator 4 is not performing cooling and dehumidifying operation), high-temperature refrigerant is poured into the evaporator 4 to remove the frost that has started to adhere to the evaporator 4 during the cooling and dehumidifying operation. It can be removed early to prevent frost formation.

In addition, during the time (time t7 + ts) from when the blower 5 stops to when the compressor 1 starts operating again in the dehumidification mode, the room temperature rises moderately due to the indoor heat load and the high temperature refrigerant flowing into the evaporator 4. As a result, the decrease in room temperature during the dehumidifying operation mode can be suppressed to a minimum.

In addition, in the middle of step 3, if the room temperature sensor 8 and the temperature determination means 17 determine that the room temperature is lower than the set temperature, the first time limit is set as shown in step 3' in FIG. Means 18 to fifth timer means 22
The timer reset works on compressor 1. The blower 5 is turned off and the dehumidification mode operation is stopped.

Step 4 When one cycle (time limit tz) of on-off control of the compressor 1 is completed through the process of Step 3, the air conditioning control means 12 turns off the on-off valve relay 15a,
The on-off valve 7 of the refrigerant bypass circuit 6 is closed. Then, the state returns to the state before step 1 again, and then, if the room temperature is higher than the set temperature, the operations from step 1 to step 4 are performed during the period t1 of the dehumidification mode.

Further, if the room temperature becomes lower than the set temperature, the process moves to step 5.

Step 5: Room temperature sensor 8. When the temperature determining means 17 determines that the room temperature is lower than the set temperature, the dehumidifying operation is stopped, the sixth time limit means 23 is activated, and the process moves to step 6.

Step 6: The time-limited tδ dehumidifying operation is stopped, and then the on-off valve relay 15a is forcibly turned off to close the on-off valve 7, and then the process moves from step 7 to step 9. The process from steps 7 to 9 is the same as the pattern from step 1 to step 3 described above except for the temperature determination, and the dehumidification operation is performed again through these series of processes. The reason for performing this forced operation is that during the dehumidification mode stop period, the blower 5 is stopped, so the indoor air is not sufficiently circulated and the indoor temperature varies from place to place. 8 may not be able to fully grasp the room temperature, and in this case, the room temperature may rise above the set temperature, so as a measure to prevent this, the compressor 1. The blower 5 is temporarily operated to create a nearly uniform temperature distribution in the indoor air and accurately grasp the room temperature situation.

Moreover, by performing a temporary cooling and dehumidifying operation, a rise in room temperature and temperature is suppressed.

According to this embodiment as described above, (1) the existing refrigeration cycle can be used to perform the dehumidifying operation, and (2) the compressor 1° blower 5 can be turned off at every cycle tl of the dehumidifying mode. Since the high-temperature refrigerant can be flowed to the evaporator 4 through the refrigerant bypass circuit 6 by using the refrigerant bypass circuit 6, frost formation on the evaporator 4 can be prevented even when the indoor temperature is low and humid. Therefore, even in a low temperature environment, efficient dehumidification operation can be performed without reducing the dehumidification performance of the evaporator 4.

(3) Furthermore, compressor 1 in dehumidification mode. In addition to the periodic intermittent operation of the blower 5, high-temperature refrigerant repeatedly flows into the evaporator 4, so at this time.

Since the indoor temperature is raised appropriately, the indoor temperature will not become too low even if the dehumidification mode operation is performed in a low-temperature environment. (5) After the dehumidifying operation mode is stopped, the sixth timer 23 temporarily closes the compressor 1. Since the air blower 5 is operated to allow the room temperature sensor 8 to appropriately detect the temperature, it is possible to accurately control the dehumidification operation.

In this embodiment, the operation of the compressor 1 and the blower 5 in the dehumidification mode is automatically controlled by the room temperature detection by the room temperature sensor 8, but instead of the low room temperature sensor, a humidity sensor is used to monitor the indoor humidity situation. It is also possible to have the user understand the information and perform the process.

Further, a frost sensor is added to the evaporator 4, and when the frost sensor detects frost of a predetermined degree or higher, the dehumidification mode operation is canceled by a signal from the frost sensor, and the refrigerant bypass circuit 6 is activated. The on-off valve 7 may be independently temporarily opened and the compressor 1 may be operated continuously.

In this way, the dehumidification mode operation is performed especially under low temperature and high humidity conditions, and the frost adhering to the evaporator 4 is completely removed by the inflow of high temperature refrigerant while the on-off valve 7 is open in the dehumidification mode operation. If the frost is not completely removed, a unique defrosting function is activated to completely remove the frost from the evaporator 4, thereby further improving the dehumidifying performance in a low-temperature environment.

(Effects of the Invention) As described above, according to the present invention, it is possible to prevent frost formation on the evaporator during dehumidification mode operation using a refrigeration cycle, so dehumidification operation with high dehumidification efficiency can be performed without any trouble even in low-temperature environments. It is possible to provide an air conditioner that can perform dehumidification without the room temperature becoming too low.

[Brief explanation of drawings]

Fig. 1 is a refrigeration cycle system diagram of an air conditioner that is an embodiment of the present invention, and Fig. 2 shows the operating states of the compressor, blower, and refrigerant bypass on-off valve used in the above embodiment during dehumidification mode operation. Output waveform diagrams, Figures 3(a) and 3(b) are circuit diagrams of the air conditioning control system of the air conditioner of the above embodiment, Figure 4 is a block diagram showing the function realizing means of the air conditioning control system, and Figure 5 The figure is a flowchart explaining the operation of the above embodiment. 1... Compressor, 1a... Compressor outlet side piping, 2.
... Condenser, 3... Decompression throttling mechanism, 4... Evaporator,
4a...Evaporator inlet side piping, 5...Blower, 6.
... Refrigerant bypass circuit, 7... Opening/closing valve, 8... Room temperature sensor, 12... Air conditioning control means, 18... First time limit means, 19... Second time limit means, 20... 3rd time limit means, 21...4th time limit means, 22...5th time limit means, 23...6th time limit means.

Claims (1)

[Scope of Claims] 1. A refrigeration cycle system including a compressor, a condenser, a pressure reduction throttling mechanism, and an evaporator arranged in a refrigerant circuit, a blower that sends air passing through the evaporator into a room, and the compressor. In the air conditioner, the air conditioner is equipped with an air conditioning control system that controls the operation of the air conditioner and the blower to keep the room at a set temperature, and the refrigerant circuit is provided at the outlet side of the compressor, bypassing the condenser and the pressure reduction throttling mechanism. A refrigerant bypass circuit is provided to connect the piping and the inlet side piping of the evaporator, and the refrigerant bypass circuit is provided with an on-off valve that remains closed during the cooling mode. a first timer for setting a cycle of the dehumidification mode when in the dehumidification mode; a second timer for controlling the operation of the compressor by on-off control for each cycle of the dehumidification mode; and a second timer for starting the operation of the compressor. a third timer for starting the blower later than the start of the compressor; a fourth timer for stopping the blower before stopping the compressor; and a fourth timer for stopping the blower before stopping the compressor. An air conditioner comprising: a fifth time limiter for controlling the opening/closing valve of the refrigerant bypass circuit between the time of stopping and the time of restarting operation of the compressor in the dehumidifying mode. . 2. In claim 1, the first to fifth timer means of the air conditioning control system are set to operate based on a detection signal of a sensor that detects indoor temperature or humidity. Air conditioner. 3. The air conditioner according to claim 1 or 2, wherein the air conditioning control system includes a sixth timer for forcibly operating the compressor and the blower temporarily after the dehumidification mode ends. .