JPH03211380A - Air conditioner - Google Patents

Abstract

PURPOSE:To shorten the defrosting operation time by providing a controller by which a defrosting two-way valve on a defrosting bypass pipe is opened when the temperature of an outdoor heat exchanger becomes below the defrosting start temperature, and the two-way valve is closed and a four-way valve is turned to the cooling position when the temperature of a heat accumulator drops below the specified temperature after defrosting operation starts. CONSTITUTION:A controller is provided, by which a two-way valve 10 on a defrosting bypass pipe 9 is opened when the temperature of an outdoor heat exchanger 8 drops below the defrosting start temperature, and the defrosting two-way valve 10 is closed and a four-way valve 5 is turned to the cooling position when the temperature of a heat accumulator 2 falls below the specified temperature after defrosting operation starts. During defrosting operation, the refrigerant which is heated to a high temperature by a compressor 1 and further absorbs heat as the heat accumulator 2 is sent to the outdoor heat exchanger 8 through the defrosting bypass pipe 9. And when defrosting is not satisfactorily carried out by the refrigerant through the defrosting bypass pipe 9, the temperature drop of the heat accumulator 2 is detected and the refrigerating cycle is turned to cooling operation mode to perform reverse defrosting operation. Thereby, the defrosting operation time can be shortened even in the case the controller is applied to a large size apparatus with a large capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat storage type air conditioner in which a heat storage tank is incorporated in a refrigeration cycle, and particularly relates to an air conditioner in which defrosting time is shortened.

[Conventional technology]

Conventional heat pump air conditioners, which can selectively perform cooling and heating operations by switching the four-way valve, incorporate a two-way valve to defrost the outdoor heat exchanger during heating operation. A method using a defrosting bypass circuit is adopted. This bypass circuit is provided to connect between the compressor and the outdoor heat exchanger. During defrosting, the two-way valve of the bypass circuit is opened, and the high-temperature refrigerant that has been adiabatically compressed by the compressor is sent to the outdoor heat exchanger.

[Problem to be solved by the invention]

However, this type of defrosting method is suitable for small models with relatively low heating and cooling capacity, but has the disadvantage that it is not suitable for large models. In other words, in a small MTI, the amount of heat added to the refrigerant by the compressor is greater than the amount of heat required for defrosting, so compared to reverse defrosting, which reverses the four-way valve and switches the refrigeration cycle to cooling operation. , the above-mentioned bypass circuit system is advantageous in terms of efficiency. On the other hand, in the case of large-sized models, the heat capacity of the compressor and the heat capacity required for defrosting are spaced between roads, etc., and the above-mentioned bypass method has the disadvantage that the required defrosting time becomes longer.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the problems of the conventional technology described above, and to provide a heat storage system that can shorten the required defrosting time even if a defrosting method using a bypass circuit is adopted for large-capacity models. Our goal is to provide type air conditioners.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a heat storage tank incorporated in piping between the discharge side of a compressor and a four-way valve, and an outlet side of the heat storage tank and an inlet side of an outdoor heat exchanger during heating. Connect the defrost bypass piping with a built-in two-way defrosting valve, and open the two-way defrosting valve of the defrosting bypass piping when the temperature of the outdoor heat exchanger falls below the defrosting start temperature. The present invention is characterized by comprising a control section that closes the two-way defrosting valve and reverses the four-way valve to the cooling position when the temperature of the heat storage tank becomes lower than a predetermined temperature after the start of defrosting.

[For production]

According to the present invention, during defrosting, the refrigerant that has been heated to a high temperature by the compressor and has absorbed heat in the heat storage tank is sent to the outdoor heat exchanger through the defrost bypass pipe. When defrosting through the defrosting bypass piping is not sufficient, reverse defrosting is performed by detecting a drop in the temperature of the heat storage tank and reversing the refrigeration cycle to cooling operation.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a circuit diagram showing a refrigeration cycle of an air conditioner according to the present invention. In the figure, reference numeral 1 indicates a compressor, and a discharge side 1a of the compressor 1 is connected to an inlet side of a heat storage tank 2 through piping. This heat storage tank 2 is provided with a heat exchanger for heat storage and a heat storage material inside thereof, and has a pair of ports 3a, 3b and an outlet 4a, s4, respectively.
It is equipped with b. An outlet 4a of the heat storage tank 2 is connected to an indoor heat exchanger 6 via a four-way valve 5 for selectively switching the refrigeration cycle between cooling operation and heating operation. This indoor heat exchanger 6 is connected to an outdoor heat exchanger 8 via a pipe in which an expansion valve 7 as a pressure reducing device is disposed. The outlet side of this outdoor heat exchanger 8 during heating is connected to the four-way valve 5 .

Moreover, this four-way valve 5 has two suction sides 1b of the compressor 1,
Connected to 1b of lc.

The outlet 4a side of the heat storage tank 2 is connected by a defrosting bypass pipe 9 between the expansion valve 7 and the inlet side of the outdoor heat exchanger 8 during heating. and.

This defrosting bypass piping 9 includes a defrosting two-way valve 10 and a capillary tube 1 in order toward the outdoor heat exchanger 8.
1 is incorporated.

Further, the suction side 1c of the compressor 1 and the outlet side of the indoor heat exchanger 6 during heating are connected by a heating start-up bypass pipe 12 so as to pass through the inlet 3b and outlet 4b sides of the heat storage tank 2. There is. A capillary tube 13 and a heating start-up two-way valve 14 that are opened at the time of heating start-up are installed in this heating room earth bypass pipe 12 in order from the outlet 4b side of the heat storage tank 2.

Next, FIG. 2 is a sequence circuit diagram of the compressor 1, four-way valve 5, two-way defrosting valve 10, and two-way heating start-up valve 14 that constitute the refrigeration cycle. Motor 1 that drives compressor 1
is connected to an AC power source 16 via a relay 15. The four-way valve 5 switches the refrigeration cycle to either cooling operation or heating operation when the relay 17 is turned ON-OFF. The normally closed type defrosting two-way valve 10 and heating start-up two-way valve 14 each have a relay 18
．． It is opened and closed by turning ON/OFF 19.

Reference numeral 20 indicates a fan motor, and this fan motor is turned on and off by a relay 21.

The relays 15, 17, 18, 19, 21 are turned on and off by a control unit 22 to which a microcomputer is applied.
FF controlled. This control unit 22 controls the outputs of a heat storage tank temperature detector 23 disposed inside the heat storage tank 2, an outdoor heat exchanger temperature detector 24 disposed in the outdoor heat exchanger 8, and an indoor temperature detector 25. Based on this, an ON/OFF signal is output to the relay. Note that the reference numeral 26 indicates a temperature setting device.

During heating operation of the air conditioner according to the present invention configured as described above, the high-temperature gas refrigerant discharged from the compressor 1 passes through the heat storage tank 2, where a part of the heat is accumulated, and then the four-way valve 5 It then enters the indoor heat exchanger 6. In this indoor heat exchanger 6, heat exchange is performed between the gas refrigerant and indoor air, heating the room. Thereafter, the refrigerant is reduced to an appropriate pressure while passing through the expansion valve 7, absorbs heat from the outside air in the outdoor heat exchanger 8, and is vaporized, after which it returns to the compressor 1.

When using the air conditioner of the present invention, the two-way heating start-up valve 14 provided in the heating start-up bypass pipe 12 is opened at the start of heating operation.

Therefore, a part of the refrigerant that exits the indoor heat exchanger 6 passes through the bypass pipe 12 for heating start-up, absorbs heat in the heat storage 162, evaporates, and is then recompressed in the compressor 1, becoming high temperature and generating indoor heat. Since the signal is sent to the exchanger 6, the start-up time is shortened.

Next, FIG. 3 is a flowchart showing the processing procedure of the microcomputer corresponding to the control section 22 during heating operation.

First, with the start of heating operation, the outdoor heat exchanger temperature detector 24 disposed in the outdoor heat exchanger 8 outputs the detected temperature Tc to the control unit 22.

The control unit 22 compares the temperature Tc of the outdoor heat exchanger 8 with the defrosting start temperature α inputted in advance via the temperature setting device 26 (step 101). The control unit 22 controls the temperature T,
Normal heating operation control is performed while the temperature is higher than the defrosting start temperature α (step 102).

On the other hand, when the temperature Tc becomes lower than the defrosting start temperature Tα, the control unit 22 performs the following defrosting operation control. That is, the temperature of the heat storage tank 2 is compared with a predetermined reverse defrosting temperature β, which is a reference for determining whether to reverse the four-way valve 5 to the cooling position and start defrosting (step 103). As a result of this determination, if the temperature TT is higher than the reverse defrosting temperature β, defrosting can be performed using the heat of the heat storage tank 2, so a solenoid (not shown) of the relay 18 is energized. Therefore, the contacts of the relay 18 are closed, and the two-way defrosting valve 10 provided in the defrosting bypass pipe 9 is opened (step 104). As a result, the high temperature gas refrigerant is introduced into the outdoor heat exchanger 8 from the heat storage tank 2 through the defrosting bypass pipe 9, so that the outdoor heat exchanger 8
Defrost is achieved by the heat of the gas refrigerant.

During defrosting, the temperature Tc of the outdoor heat exchanger 8 is compared with a preset defrosting end temperature γ (step 105), and the temperature Tc is lower than the defrosting end temperature γ. In other words, if defrosting is not yet sufficient, the process returns to step 103.

When the temperature TT of the heat storage tank 2 is higher than the reverse defrosting temperature β, defrosting is continued using the defrosting bypass pipe 9 described above. Thereafter, when the temperature Tc becomes higher than the defrosting end temperature γ, it is confirmed that the four-way valve 5 is in the heating position (step 106), and the defrosting ends. In defrosting using such defrosting bypass piping 9, the amount of heat released by the gas refrigerant directly sent from the heat storage tank 2 during defrosting is equal to the amount of heat added by the work of the compressor 1 and the amount of heat absorbed by the heat storage tank 2. Therefore, even for large models, the required defrosting time can be shortened.

On the other hand, in step 103, when the temperature of one heat storage tank 2 becomes lower than the reverse defrosting temperature β, that is, when defrosting using the defrosting bypass piping 9 is insufficient. When the relay 18 is turned OFF and the two-way defrosting valve 10 is closed, the relay 17 is also turned OFF.
The four-way valve 5 is switched to the cooling position, and reverse defrosting is performed (step 107). As a result, the refrigeration cycle enters cooling operation, so that the heat of the refrigerant is released in the outdoor heat exchanger 8. After that, the temperature Tc of the outdoor heat exchanger 8
After waiting for the temperature to become higher than the defrosting end temperature γ (step 105), the relay 17 is turned on and the four-way valve 5 is switched to the heating position (step 106). By adding reverse defrosting as described above, sufficient defrosting can be performed without residual frost.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a defrosting bypass pipe is provided that connects the outlet side of the heat storage tank and the inlet side of the outdoor heat exchanger during heating and incorporates a two-way valve for defrosting. When the temperature of the outdoor heat exchanger falls below the defrosting start temperature, the defrosting two-way valve of the defrosting bypass piping is opened, and after the defrosting starts, the temperature of the heat storage tank reaches the predetermined temperature. Since the two-way defrosting valve can be closed and the four-way valve reversed to the cooling position when the temperature drops below the temperature, the time required for defrosting can be shortened even when applied to large models with high capacity. Not only is it possible to do this, but it also has the effect of being able to exhibit sufficient defrosting ability even when heating in places with severe conditions such as extremely cold regions.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an air conditioner according to the present invention, FIG. 2 is a sequence circuit diagram of a refrigeration cycle of the air conditioner, and FIG.
The figure is a flowchart describing the operation of the control unit included in the air conditioner. 1... Compressor, 2... Heat storage tank, 5... Four-way valve, 6
... Indoor heat exchanger, 7... Expansion valve, 8... Outdoor heat exchanger, 9... Bypass piping for defrosting, 10... Two-way valve for defrosting, 12... Heating Start-up bypass piping, 14..., two-way valve for heating start-up, 22... control section.

Claims (1)

[Claims] In an air conditioner that consists of a compressor, four-way valve, indoor heat exchanger, pressure reducer, and outdoor heat exchanger to form a refrigeration cycle and can selectively switch between cooling and heating operation, the a heat storage tank built into the piping; a defrosting bypass pipe incorporating a two-way valve for defrosting that connects the outlet side of the heat storage tank and the inlet side of the outdoor heat exchanger during heating;
When the temperature of the outdoor heat exchanger falls below the defrosting start temperature, the defrosting two-way valve of the defrosting bypass piping is opened, and after the start of defrosting, when the temperature of the heat storage tank falls below the predetermined temperature. An air conditioner comprising a control unit that closes a two-way defrosting valve and reverses a four-way valve to a cooling position.