JPS59229124A - Air conditioner for plurality of rooms - Google Patents

Abstract

PURPOSE:To prevent the outlet temperature from being extremely lowered during multi-rooms operation, by constituting an apparatus so that an indoor fan is shifted down to a weak air operation when a plurality of rooms are heated, in the titled apparatus in which many outdoor units are connected to an indoor unit, being able to be changed over by a four-way directional control valve. CONSTITUTION:A heating switch 19 is turned ON, and each unit 2a and 2b is respectively controlled by thermostats 18a and 18b for room temperature in accordance with the condition of each room. In this case when both fans 17a and 17b are in the strong air condition and the thermostats 18a and 18b are closed, relays 20a and 20b are energized, and the normally opened contact points 21a' and 21b' of a relay 21 for indoor fan are closed, while the normally closed contact points 21a an 21b are opened by switches 20a' and 20b'. Then the fans 17a and 17b are changed over to a low speed operation. By forcibly changing over the fans to low speed during a multi-rooms operation, the temperature in the output air is prevented from being lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-room air conditioning and heating system in which a plurality of indoor units are connected to one outdoor unit and heating and cooling is possible by switching a four-way switching valve.

Normally, even in this type of air conditioning system, the indoor fan of the indoor unit can be switched between strong and weak winds, responding to the user's preference, but on the other hand, it is difficult to operate the indoor fan during heating operation and multi-room operation. In this case, it is inevitable that the heating capacity will decrease. During multi-room heating, if the indoor fan is operated under strong wind conditions, the air outlet temperature tends to drop significantly as the heating capacity is reduced, which is not desirable.

The present invention solves these drawbacks and prevents the blowout temperature from dropping excessively even in multi-chamber operation.One embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, two indoor units 2Δ and 2bi refrigerant piping are connected to one outdoor unit 1. Inside the outdoor unit 1 is a compressor 3 and a four-way switching valve 4.
, an outdoor coil 5 that becomes an evaporator during heating, a pressure reducer 6 for heating, a liquid receiver 7, and an accumulator 8 are connected to the cooling condenser by piping, and the liquid receiver 7 is connected to each unino) 2a, 2b.
Liquid side branch pipes ga and 9b are installed to the switching valve 4, and gas side branch pipes 10a and 10 to each unit 2a and 2b are installed.
0b is provided. Furthermore, electromagnetic valves 11a, 11b, 12a, and 12b are interposed in each of these branch pipes to control the flow of refrigerant. 13 is an outdoor fan that cools the outdoor coil 5. On the other hand, each indoor unit 2a, 2bK has a cooling pressure reducer 141L, 14b, and an indoor coil 15a which serves as an evaporator during cooling and a condenser during heating.

15b is each branch pipe 9a, 9b, 101L, 10blC
Connected and also auxiliary heater during heating 16&, 16b%
Indoor fan that can be switched between strong wind and weak wind operation.

17b are arranged respectively. Therefore, the operating state of the above system is that during cooling, the refrigerant flows as shown by the solid line arrow in the figure, and during heating, the refrigerant flows as shown by the broken line arrow by switching the four-way switching valve 4, and the refrigerant flows between two rooms or two by opening and closing the solenoid valve as appropriate. Single room operation is possible.

Next, a schematic electrical circuit diagram focusing on heating operation in the above device will be explained with reference to FIG. 2. Each of the above) 21L
, 2b are provided with room temperature thermostats 18a, 1sb which sense the room temperature and turn ON/OFF, and are connected in series with a heating operation switch 19 which is operated during heating. (Usually, this switch 19 is provided in each of the units 2a and 2b, but for the sake of explanation, it will be combined into one unit.) ) Furthermore, the above room temperature thermometer 18! The solenoid valves 11&, 12a and 1 operate in accordance with the OK-OFFVC of L and 18b.
1b.

12b' (i-opening/closing solenoid valve coil 11 a'j1
2a'.

and 1 l b', 12b' and further relay 20IL
and 20b are connected through a parallel V. These relays 20a.

20 bid, a switch 20 that closes when energized.

20b"i, and these switches 2o2L', 2ob' and an indoor fan relay 21 are connected in series.

On the other hand, the indoor fans 17a and 17b each have a high speed terminal H and a low speed terminal H, and each indoor unit 21L,
2b is connected to the valley contact of the speed changeover switch 22 & , 221). In addition, V-21 [% unit 21L for indoor fan, normally closed contact 211L for 2b,
A pair of switches consisting of a normally open contact 21&', 21t)' is provided, and a room temperature thermostat 18&, 18b,
Normally closed contact 21a of the switch.

21b, speed switching switches 221L, 22b, indoor fans 171L, 17b are wired in series with the power supply, and the normally open contacts 21L', 21b' of the switches are connected to the normally closed contacts 21&, 21b for speed switching. switch 2:2
Fan 17a to bypass L, 22b.

It is connected between the low speed terminal 17b and the thermostats 18L and 18b. Naturally, the normally closed and normally open contacts of the above-mentioned switch work so as to correspond to each other by the indoor fan relay 21, and when the normally open contacts 21a' and 21b' are closed, they are related to the high speed and low speed of the speed changeover switches 221L and 22b. Instead, the indoor fans 17&, 17b are supplied with power to the low speed terminals to perform low speed operation.

In the above circuit, the circuits for the auxiliary heaters 161L and 16b are omitted.

That is, to explain the operation of the above circuit, when the heating switch 19 is turned on, the room temperature thermostat 18a is activated depending on the situation in the room in which the units 21L and 2b are installed.

Optional operation of one or two chambers is performed by temperature sensing at 18b. Also, each unit) 2a, 2b fans 17 &
, 17b, the speed changeover switch 221L,
22b is in any state of strong wind 1 weak wind. Here, both fans 171L and 17b are in a strong wind condition,
Moreover, considering the case where thermostats 18L and 18kl are both closed, relays 20&.

Since both 20b and 20b are energized, the switch 2oe:.

2ob' energizes the indoor fan relay 21,
Therefore, normally open contacts 21a' and 21b' are closed, and normally closed contact 2
1 &, 21 b will be opened. That is, fan 17
Power to the high speed terminals of 1L and 17b is cut off, and power to the low speed terminals is started. This is when two units) 21L and 2b are both energized.

This prevents a decrease in the blowout temperature due to a decrease in capacity and continued strong wind conditions.

As is clear from the above explanation, according to the present invention, when multi-room heating operation is started, the wind is forcibly switched to weak air regardless of the operating status of the fan of each unit, so that the airflow during multi-room heating operation is reduced. Comfortable heating is performed without promoting a drop in temperature.

[Brief explanation of drawings]

FIG. 1 is a cooling cycle diagram of a heating and cooling system according to an embodiment of the present invention, and FIG. 2 is a schematic electrical circuit diagram mainly used during heating of the system. 1... Outdoor unit %la, 2b old... indoor unit, 4... Four-way switching valve, 171L, 1
7b...Indoor 77y, 21 &, 21
b, 21 a', 21 b' --- Normally closed contact,
Normally open contact (switch).

Claims (1)

[Claims] In a multi-room air conditioning/heating system in which a plurality of indoor units each having an indoor fan that can operate at high and low speeds is connected to one outdoor unit, and heating and cooling is possible by switching a four-way switching valve, the indoor fan is turned off during heating and multi-room operation. A multi-room air conditioning/heating system characterized by being equipped with a switch that forcibly switches to low-wind operation.