JPH02118364A - Air conditioner - Google Patents

Abstract

PURPOSE:To make possible an optimum air conditioning operation at all times irrespective of the number of operation rooms by a method wherein two-way valves connected to the input and output sides of a heat exchanger in non-operational indoor device are constituted to be opened and closed controllably in accordance with the operational condition of a refrigerating cycle. CONSTITUTION:When a controller 8 receives a signal, which indicates the shortage of refrigerant, from a temperature sensor 7, a two-way valve of one of other indoor devices, for example, a two-way valve 52c of an indoor device 52 is opened by a predetermined period of time and is controlled so as to lower an outlet temperature by the supply of the refrigerant. When the short state of the refrigerant still continues under this condition, the two-way valve 52c is opened again by a predetermined period of time in the same manner and is controlled so as to repeat this method several times at regular intervals until the outlet temperature is lowered down to a detected temperature or below. On the contrary, when the outlet temperature is too low and it is indicated that the refrigerant is in an excessive state, a two-way valve 52b on the inlet side of a heat exchanger 52a is brought into an open state by a predetermined period of time to accumulate the excessive refrigerant into the indoor device 52 so that the outlet temperature is increased to secure the optimum operation of an air conditioner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement in an air conditioner configured to enable parallel operation of a plurality of indoor units.

(Prior Art) FIG. 3 shows the configuration of a conventional multi-type air conditioner in which multiple indoor units are operated in parallel.

That is, the compressor 1 is connected to a four-way valve 2, and a plurality of indoor units 51, 52, 53 are connected to the four-way valve 2 via an outdoor heat exchanger 3 and an expansion valve 4.

Each indoor unit 51, 52.53 is an indoor heat exchanger 51a, 52
a, 53a, and a two-way valve 51b on the inlet/outlet side of each heat exchanger.

51c, 52b, 52c, 53b, 53c are connected to each other, and the expansion valve 4 and each indoor heat exchanger 51
a, 52a, and 53a, there is a capillary tube 51
d, 52d, 52d', and 53d are connected in parallel or series with the two-way valve. Furthermore, an accumulator 6 is connected between the compressor 1 and the four-way valve 2 on the outdoor side.

In the refrigeration cycle of the conventional air conditioner mentioned above,
The amount of refrigerant is adjusted and sealed so as to achieve the most efficient operating state during full-room operation, and at that time, all of the two-way valves are operated in an "open" state.

By the way, in the case of partial operation where only one or two of the indoor units are operated, one question is asked only for the two-way valve of the indoor unit being operated, and one question is asked for the two-way valve of the indoor unit that is not in operation. All the direction valves are switched to the "closed" state and operated.

Therefore, the refrigerant accumulated in the heat exchanger of the indoor unit that is not in operation is recovered into the air conditioning refrigeration cycle through the capillary tube, so when only one or two rooms are operated, there may be an excess of refrigerant in the refrigeration cycle. Accumulator 6 operates to compensate.

However, installing the accumulator 6 on the outdoor unit side increases the size of the device, which is contrary to the desire to downsize the harmonizer as a whole and reduce the number of component parts.

Furthermore, if the accumulator is omitted, if the indoor unit is partially operated, the refrigerant will be over-operated, leading to a decrease in heating and cooling capacity and problems with the compressor due to liquid back up.

(Problems to be Solved by the Invention) In conventional air conditioners, when adopting a parallel operation configuration of multiple indoor units, it is unavoidable to increase the size of the outdoor unit due to the installation of an accumulator, and omitting the accumulator reduces the air conditioning operation capacity. This has the drawback of causing a decrease in the performance of the compressor or failure of the compressor.

Therefore, an object of the present invention is to provide an air conditioner with a simple configuration and high operating efficiency.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a multi-type air conditioner configured to enable parallel operation of a plurality of indoor units. The invention is characterized in that at least one of the two-way valves connected to the refrigeration cycle can be controlled to open or close depending on the operating status of the refrigeration cycle.

(Function) The air conditioner of the present invention is configured such that at least one of the two-way valves on the input and output sides of the non-operating indoor unit can be controlled to open and close depending on the operating status of the refrigeration cycle. The refrigerant accumulated in the heat exchanger during operation is adjusted by controlling the opening and closing of the two-way valve, which makes it possible to adjust the amount of refrigerant depending on the operating conditions of the air machine.

Therefore, an accumulator is not particularly required on the outdoor side, and moreover, efficient operation can be performed.

(Embodiments) Hereinafter, embodiments of the air conditioner according to the present invention will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a block diagram showing an embodiment of an air conditioner according to the present invention.

Note that the same components as those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

Specifically, the compressor 1 is connected to a four-way valve 2, and a plurality of indoor units 51, 52, . . . , 5N are connected to the four-way valve 2 via an outdoor heat exchanger 3 and an expansion valve 4.

Each indoor unit 51.52-5N includes an indoor heat exchanger 51a,
52a.

-5Na, two-way valves 51b and 51c on the inlet and outlet sides, respectively.
52b, 52c.

-Configured by connecting -5Nb and 5Nc.

A temperature sensor 7 for detecting the operating state of the refrigeration cycle is provided in the discharge pipe of the compressor 1, and the temperature detection output signal is sent to the controller 8.
supplied to The controller 8 receives the signal from the temperature sensor 7 and the operation command signal from the indoor unit operation control switch 9.
Each of the two-way valves 51b.

51c, 52b, 52c, and 5Nc, respectively, and can be configured by a microcomputer circuit, for example. The indoor unit operation control switch 9 is connected to each indoor unit 51, 52 . . . . Command switches 951, 952 . . . which supply operation command signals in response to 5N. ...95N
It consists of Although a temperature sensor is provided in this embodiment to detect the operating state of the refrigeration cycle, it is also possible to use a pressure sensor that directly detects the refrigerant pressure itself, for example.

The operation of the embodiment having the above configuration will be explained with reference to FIG.

FIG. 2 shows the opening/closing control state of each two-way valve and the temperature of the discharge pipe measured by the sensor 7, that is, the change in refrigerant discharge temperature as the operating time elapses.

Assume now that the air conditioner is operated in a heating cycle, and that the refrigerant is sealed in such a way that the optimum operating state is achieved when all the heat exchangers are operated at the same time.

Therefore, to explain the control operation of an air conditioner when only one indoor unit 51 is operated as an example, first, at the start of operation, all two-way valves are operated by the control signal from the controller 8. Set.

Next, when 11 hours have passed after the start of operation, the corresponding two-way valves 52 of all other indoor units except the indoor unit 51 in normal operation
b... 5Nc is closed and only the indoor unit 51 is set to the heating operation state.

While operation continues in this state, other non-operating heat exchangers 5
2...5N are each in a state where refrigerant is accumulated, so
Normally, the indoor unit 51 maintains a normal operating state.

However, when the air conditioning load on the indoor unit 51 becomes large and the circulating refrigerant becomes insufficient, the temperature sensor 7 of the discharge pipe detects a temperature rise, and when the detected temperature exceeds 11, the refrigerant is insufficient. It is supplied to the controller 8 as a signal indicating this.

When the controller 8 receives a signal indicating refrigerant shortage from the temperature sensor 7, it opens one of the other indoor units 2, for example, the two-way valve 52c of the indoor unit 52, for a predetermined time t2 (a) to stop the refrigerant supply. Il control is performed to lower the discharge temperature.

If the refrigerant shortage condition continues even in this state, the two-way valve 52c is opened again for a certain period of time t2 (b), and this is repeated at intervals until the discharge temperature becomes 11 or less. Control as many times as you like. If the refrigerant in the indoor heat exchanger 52a does not reach a temperature of 1 or less, if the indoor unit is configured with three units, additionally control the two-way valve of the other indoor unit n53 in the same manner as described above. Control is repeated until the discharge temperature becomes H or less to ensure normal operation.

Next, when the discharge temperature is too low and is below T2, indicating that the refrigerant is in an excessive state, the two-way valve 52b on the inlet side of the heat exchanger 52a is opened for a certain period of time t3,
Excess refrigerant is stored in the indoor unit 52, and the temperature is increased to ensure proper operation.

In this case as well, as in the case of discharge temperature rise, - constant time t
By repeating the intermittent open state in step 3 and additional operations of other indoor units, the entire system is controlled to ensure proper operation.

Moreover, although the case where only one indoor unit 51 is operated has been described as an example, the present invention can similarly be applied to cases where only one indoor unit 51 is operated, not limited to - units.

The above has been explained for the case of heating operation, but also for cooling operation, the entrance and exit of the two-way valve is exactly opposite to that during heating,
Therefore, the refrigerant amount can be appropriately controlled in the same way by simply reversing the control.

As described above, the air conditioner according to the present invention does not require an accumulator on the outdoor unit side, and the refrigerant is adjusted according to the operating number of the indoor unit and the state of the refrigeration cycle, such as the temperature or refrigerant pressure of the refrigeration cycle. Since the amount is controlled, optimal and efficient operation is always possible.

Furthermore, since only a discharge temperature sensor and a two-way valve control circuit system including a microcomputer and the like are added to the configuration, it is possible to realize a compact air conditioner with a simple circuit.

[Effects of the Invention] As explained above, the air conditioner according to the present invention controls each two-way valve of the indoor unit based on the state of the refrigeration cycle such as the discharge temperature of the compressor, so that the air conditioner always operates regardless of the number of operating rooms. This allows for optimal air conditioning operation, which has great practical effects.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an embodiment of an air conditioner according to the present invention, Fig. 2 is a timing chart showing the operation control state of the air conditioner shown in Fig. 1, and Fig. 3 is a diagram showing a conventional air conditioner. FIG. 1... Compressor 2... Four-way valve 3... Outdoor heat exchanger 51.52. ...5N...Indoor units 51a, 52a,...5Na...Indoor heat exchanger 5
1b, 51c, 52b, 52c,...5Nb, 5N
c...Two-way valve 7...Temperature sensor 8...Controller 9...Indoor unit operation control switch Agent Patent attorney Norihiro Ogo 1. S'1 --- 5N, Riyatsuji゛klo,, Uruguay 2a ---,! rNa, ”t-re elevation Fn(
Menhigeto old 1b, uran 1e, AXmu, SZC, ---SN
b,! 3Nc. 2-way valve 7, 2-way valve 2, Iap 2-way valve

Claims (1)

[Claims] In a multi-type air conditioner that is configured to allow multiple indoor units to operate in parallel, at least one of the two-way valves connected to the input/output side of the heat exchanger of the non-operating indoor units is used to operate the refrigeration cycle. An air conditioner characterized by being configured to be able to be opened and closed depending on the situation.