JPH0337105B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air conditioner, and particularly to a so-called multi-type heat pump air conditioner that is equipped with a plurality of indoor units and can heat and cool multiple rooms at the same time. The present invention relates to measures for shortening the operating time of heating hot start operation to prevent cold draft.

(Prior Art) Conventionally, as disclosed in, for example, Japanese Unexamined Patent Publication No. 19666/1983, multiple indoor units are connected in parallel to one outdoor unit to allow heating and cooling of multiple rooms at the same time. The so-called multi-type heat pump air conditioner is well known. And, in this kind of multi-type air conditioner, like a normal separate air conditioner,
When starting heating operation (including when starting heating operation after defrosting operation is finished), the indoor ventilation fan should be stopped until the refrigerant pressure rises to the specified value to prevent cold draft. A so-called heating hot start operation is performed in which heating operation is performed in a state where the heating temperature is maintained.

(Problem to be Solved by the Invention) However, in the conventional multi-type air conditioner described above, when operating a small number of rooms in which only the indoor units in some rooms are operated, the number of indoor units varies depending on the number of rooms (number of indoor units). In addition to controlling the capacity of the compressor in the outdoor unit, the system also cuts off the flow of refrigerant to the indoor unit that is not operating. For this reason, in the heating hot start operation in this small room operation, since the amount of refrigerant circulation is small, the pressure rise of the refrigerant is slow, and the heating hot start operation time becomes long. As a result, the heating capacity decreases accordingly, resulting in inferior heating comfort.

(Object of the Invention) The present invention has been made in view of the above points, and during such heating hot start operation, that is, at the start of heating operation (including the time when heating operation starts after the end of defrosting operation), By operating the compressor at almost maximum capacity regardless of the number of operating rooms (number of indoor units) and by circulating refrigerant even to indoor units that are stopped, increasing the amount of refrigerant circulating. The purpose is to accelerate the rise in refrigerant pressure and shorten the heating hot start operation time.

(Means for solving the problem) In order to achieve the above object, the solving means of the present invention provides a compressor 1 built-in compressor 1 as shown in FIG.
In an air conditioner equipped with a plurality of indoor units Y, Y' connected in parallel to one outdoor unit a capacity adjustment means 42 for adjusting the capacity of the compressor 1; and a capacity adjustment means 42 for controlling the capacity of the compressor 1, and controlling each distribution means 17 to allow the refrigerant to flow to each indoor unit Y, Y' at the start of heating operation. The compressor 1 is also provided with a control means 40 for controlling the capacity adjustment means 42 so that the capacity of the compressor 1 is approximately maximized.

(Function) With the above configuration, in the present invention, at the start of heating operation, each distribution means 17 and capacity adjustment means 42 are controlled by the control means 40, regardless of whether each indoor unit Y, Y' is operated or stopped. First, the refrigerant flows to all the indoor units Y, Y', and the capacity of the compressor 1 becomes almost the maximum, so the amount of refrigerant circulated increases. As a result, the refrigerant pressure increases quickly, and the heating hot start operation time can be shortened.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 2 onwards.

Figure 2 shows the refrigerant piping system of a multi-type heat pump air conditioner placed in a high-rise building, etc., where X is an outdoor unit, Y and Y' are indoor units each placed in a room on a given floor, and Z is an indoor unit similarly arranged in a room on a predetermined floor, and inside the upper room outdoor unit The evaporation temperature of the outdoor heat exchanger 3, which has a four-way switching valve 2 that switches as shown in FIG. A heating expansion valve 4 for adjusting the temperature and an accumulator 5 are built-in as main devices, and the devices 1 to 5 are connected to each other through refrigerant piping 8 so that refrigerant can flow therethrough.

On the other hand, the three indoor units Y to Z have the same configuration, and as shown in FIG. an indoor heat exchanger 10 having a cooling capillary tube 11;
A motor-operated valve 12 that corrects the throttle opening of the capillary tube 11 during cooling operation and functions as a dual solenoid valve is built-in, and each of the devices 10 to 1
2 are connected to each other through refrigerant pipes 15 . . . so that refrigerant can flow therethrough. Indoor units Y, Y' and Z arranged in two rooms on the same floor are connected in parallel to the above-mentioned outdoor unit X through refrigerant pipes 16, respectively. During heating operation, the refrigerant from the compressor 1 is circulated as shown by the broken line arrows in FIGS. Heat is repeatedly radiated into the indoor air by the indoor heat exchangers 10 of each indoor unit Y to Z to simultaneously heat two rooms on a given floor, while during cooling operation, the refrigerant from the compressor 1 is transferred to the indoor air as shown in Fig. 2. And by circulating as shown by the solid line arrow in Figure 3,
The refrigerant circulation cycle is reversed to the above,
Two rooms on a given floor are cooled at the same time.

Then, by opening and closing the refrigerant piping 15 using the electric valves 12 of the three indoor units Y to Z, a distribution means 17 is provided which allows and blocks the flow of refrigerant to each of the indoor units Y to Z, respectively. It consists of

In the indoor unit , part of the refrigerant discharged from the compressor 1 is immediately unloaded into the compressor 1 to perform capacity control operation, while at the time of switching to the suction side shown by the solid line, the unloading is stopped and the refrigerant is It is designed to perform full capacity operation, and constitutes capacity adjustment means 42 for adjusting the capacity of the compressor 1.

Furthermore, 20 is a liquid receiver, and the liquid receiver 20
is a flow path 2 exclusively for heating with a heating expansion valve 4 interposed therein.
Electromagnetic valves 2 are disposed upstream of the heating expansion valve 4 of No. 1, and immediately upstream and downstream of the liquid receiver 20, respectively, open the heating-only flow path 21 only during heating operation.
2 and 23 are arranged, and during heating operation, excess refrigeration generated due to changes in the number of operating indoor units, etc., is stored in the liquid receiver 20, and during cooling operation, the liquid accumulated in the liquid receiver 20 is stored. Refrigerant check valve 2
4 and the capillary tube 25, the pressure is returned to the low pressure side between the four-way switching valve 2 and each of the indoor units Y to Z. In the outdoor unit It is intended to be returned. In addition, HPS is a high pressure switch for protecting compressor 1,
PS1 and PS2 are pressure switches that detect the pressure of the refrigerant discharged from the compressor 1, and the pressure switch PS1 is turned off when the pressure value exceeds a predetermined value (for example, 19 kg/cm ² ). P.S.
2 is one that turns OFF when the pressure value exceeds another predetermined value (for example, 24 kg/cm ² ).

In each of the indoor units Y to Z, as shown in FIG. 4, a CPU and the like are installed as control means for controlling the operation of the flow means 17 (electric valve) and the capacity adjustment means 42 (three-way solenoid valve 19). A built-in control circuit 40 is provided, and various operation control signals from a remote control device 41 having a cooling/heating switch or the like can be input to the control circuit 40. When the control circuit 40 receives a heating operation start signal from the remote control device 41 (including a heating operation start signal after the end of the defrosting operation), the control circuit 40 controls each indoor unit Y to
Each electric valve 12 of Z is opened to allow refrigerant to flow through each indoor unit Y to Z, and the three-way solenoid valve 19 is switched to the suction side to operate the compressor 1 at full capacity. .

Therefore, in the above embodiment, at the start of the heating operation (including when the heating operation is started after the end of the defrosting operation), each distribution means 17 is controlled by the control circuit 40, and the distribution means 17 are controlled by the control circuit 40 to The electric valve 12 opens and the refrigerant flows through each indoor unit Y to Z, and the control circuit 40 controls the capacity adjustment means 4.
2 is controlled, the three-way solenoid valve 19 is switched to the suction side, and the compressor 1 is operated at full capacity. This increases the amount of refrigerant circulated, so the pressure of the refrigerant increases quickly, and the heating hot start operation time can be shortened. Further, by shortening the heating hot start operation time, the heating capacity is improved accordingly, and the comfortable heating performance can be improved.

(Effects of the Invention) As explained above, according to the present invention, in a multi-type heat pump air conditioner, when the heating operation starts, each indoor unit is activated or By circulating the refrigerant and operating the compressor at almost maximum capacity to increase the amount of refrigerant circulation, the heating hot start operation time can be shortened, and the heating capacity can be increased accordingly. , it is possible to achieve comfortable heating.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention. Figures 2 to 4 show embodiments of the present invention, with Figure 2 being a refrigerant piping system diagram, Figure 3 being a refrigerant piping system diagram showing the internal configuration of the indoor unit, and Figure 4 being a block diagram showing the control circuit. It is a diagram. X...Outdoor unit, Y, Y', Z...Indoor unit, 1...Compressor, 10...Indoor heat exchanger,
12... Electric valve, 17... Distribution means, 19... Three-way solenoid valve, 40... Control circuit, 42... Capacity adjustment means.

Claims (1)

[Claims] 1. In an air conditioner equipped with a plurality of indoor units Y, Y' that are connected in parallel to one outdoor unit X containing a compressor 1 and operated simultaneously, a distribution means 17 for respectively allowing and blocking the flow of refrigerant; a capacity adjustment means 42 for adjusting the capacity of the compressor 1;
At the start of heating operation, control means controls each distribution means 17 to allow the flow of refrigerant to each indoor unit Y, Y', and controls the capacity adjustment means 42 so that the capacity of the compressor 1 is approximately maximized. An air conditioner characterized by comprising: 40.