JPS63263354A - Air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an air conditioner.

Conventional technology In the past, many methods were used to control the refrigerant used in air conditioners, using capillaries to control the amount of refrigerant flowing through the evaporator. Electric expansion valves, which have a variable flow rate and control the flow rate to match the load, have come into widespread use. When determining the opening degree of the electric expansion valve, the temperature difference between the saturation temperature of the refrigerant pressure on the outlet side of the evaporator and the actual temperature of the refrigerant, that is, the degree of superheat, is detected, and the degree of superheat is kept constant. The machine is controlled.

Hereinafter, conventional refrigerant control examples and detection examples will be described with reference to the drawings.

Figure 2 is a refrigeration cycle diagram of a conventional air conditioner, where 1 is a compressor, 2 is a condenser installed outside the room, and 3 is an electric expansion installed inside the room that is driven by receiving an electrical signal. valve, 4
is an evaporator provided on the indoor side, which is connected in a ring shape through a refrigerant pipe 6 to form a refrigeration cycle.

Further, the outlet section 6 of the evaporator 4 is connected to a heat exchange pipe 8 located on the windward side of the evaporator 4 on the windward side of the indoor fan 7, and exchanges heat with the indoor suction air temperature.

A first sensor 1o is provided at the outlet portion 9 of the heat exchange tube 8, which is fixed in close contact with the tube wall and detects the temperature of the tube. Further, a second sensor 12 is provided at the inlet portion 11 of the evaporator 4 in close contact with a pipe for detecting the saturation temperature of the refrigerant which has been throttled by the electric expansion valve 3 and has become a two-phase flow. A drive unit 13 is provided to control the throttle amount of the electric expansion valve 3, and detects the temperature difference between the first sensor 1o and the second sensor 12, which corresponds to the pressure loss in the evaporator 4. The temperature value is stored, the degree of superheating at the first sensor 10 is calculated, and a signal is given to the electric expansion valve 3.

Next, the operation of the air conditioner configured as above will be explained.

The flow direction of the refrigerant is shown in FIG. 2 by solid arrows.

The refrigerant discharged from the compressor 1 is condensed and liquefied in a condenser 2, then throttled by an electric expansion valve 3, and guided to an evaporator 4 where it is evaporated. At this time, the indoor fan 7 sucks air around the heat exchange tube 8 and the evaporator 4 to perform cooling. After sufficient heat is exchanged in the evaporator 4 at the outlet 6 of the evaporator 4 to completely evaporate the refrigerant, heat is exchanged with the indoor air in the heat exchange tube 8, and the refrigerant is superheated.

Thereafter, it returns to the compressor 1 via the outlet section 9. The opening/closing throttling action of the electric expansion valve 3 at this time is controlled by a second sensor 12 provided at the inlet portion 11 of the evaporator 4 and detecting the saturation temperature of the refrigerant.
A temperature value corresponding to the pressure loss in the evaporator 4 and the temperature base of the first sensor 1o provided at the outlet part 9 and detecting the temperature of the superheated refrigerant are stored in advance, and the pressure loss is added to the temperature difference. This is done by adding and calculating the temperature value in the drive unit 13, which performs calculation processing, and then sets the temperature to an appropriate degree of superheat. However, this appropriate degree of superheating is defined as 1. This is to absorb variations in temperature detection by the second sensors 10 and 12, and in reality, a superheat degree of 0 is ideal.

Problems to be Solved by the Invention However, in the above configuration, the evaporator evaporates sufficiently so that the degree of superheating becomes 0, and the evaporator is used effectively.
A separate heat exchange tube is required to increase the degree of superheat to absorb variations in the sensor and to make it easier to detect the degree of superheat, which poses a problem in that it requires additional costs.

In view of the above problems, the present invention provides an air conditioner that controls the degree of superheating in the evaporator to zero.

Means for Solving the Problems In order to solve the above problems, the air conditioner of the present invention is configured to exchange heat between the condensate refrigerant and the piping at the outlet of the evaporator.

According to the above-described configuration, the present invention can easily raise the temperature of the evaporator outlet if it is a gaseous refrigerant with a degree of superheat of 0, and if it contains a two-phase liquid refrigerant, Since the amount of heat exchange is controlled so that the temperature does not rise, the state of the refrigerant on the evaporator outlet side can be easily detected.

EXAMPLE Hereinafter, an air conditioner according to an example of the present invention will be described with reference to the drawings.

Incidentally, the same components as those in the prior art are denoted by the same numbers and detailed explanation thereof will be omitted.

Between the outlet part 6 of the evaporator 4 and the compressor 1, there is a connecting part 1 which is brought into close contact with the condenser 2 and the electric expansion valve 3 for heat exchange.
4, and the refrigerant pipe 6 between the coupling part 14 and the compressor 1 is provided with a first sensor 10 for detecting the temperature of the refrigerant.

The operation of the air conditioner configured as described above will be explained below. However, since the basic flow of refrigerant has already been explained in the conventional example, the flow of refrigerant through the condenser will be mainly explained here.

In the figure, the flow direction of the refrigerant is indicated by a solid arrow.

The condensed refrigerant flowing from the condenser 2 is transferred to the outlet section 6 of the evaporator 4.
The condensed liquid refrigerant is further cooled by heat exchange at the coupling part 14 provided in the refrigerant, and becomes a supercooled liquid with further lowered refrigerant enthalpy, which is then throttled by the electric expansion valve 3 to form a mixed state of gas and liquid. In other words, it is a two-phase flow. Therefore, the refrigerant is
Since it is in a saturated state, pressure and temperature have a perfect correlation and indicate the saturation temperature. The temperature in this state is detected by the second sensor 12 and input to the drive unit 13. The refrigerant then enters the evaporator 4, performs cooling and evaporates completely, and reaches the outlet 6 of the evaporator 4 with a degree of superheat of 0.
state, and is further guided to the joint 14, and the joint 1
At step 4, heat is exchanged with the liquid refrigerant from the condenser 2, and the degree of superheating is further increased. At this time, since the refrigerant from the evaporator 4 has completely evaporated and cooling has been effectively performed, there is no problem of reduction in cooling capacity.

The refrigerant flowing through the joint 14 is then transferred to the first sensor 1.
0, the temperature between the compressor 1 and the coupling section 14 is detected, and the temperature value is input to the drive section 13.

In this way, the drive unit 13 includes the second sensor 12 and
The temperature information of the first sensor 10 is input, and further,
By adding the temperature configuration value corresponding to the pressure loss of the evaporator 4, the superheated state of the refrigerant at the second sensor 10 is calculated. The overheating state of the second sensor 10 at this time is
It is determined by the length of the coupling portion 14, and is set at the minimum value that can sufficiently absorb variations in temperature detection by the sensor.

The refrigerant then returns to the compressor 1 through the refrigerant pipe 5, forming a refrigeration cycle.

As described above, according to this embodiment, since heat is exchanged between the condensed refrigerant and the temperature at the evaporator outlet at the joint, the refrigerant with a degree of superheat of 0 is quickly superheated, and sensor variations are sufficiently absorbed. The temperature rise value is obtained as much as possible.

Effects of the Invention As described above, the present invention provides a connecting portion that exchanges heat between the condenser and the electric expansion valve and the outlet of the evaporator, and maintains a temperature between the connecting portion and the compressor. Detected by a sensor, and further
A second sensor is provided to detect the temperature at the inlet of the evaporator,
Since the electric expansion valve is driven by the temperature difference between the first sensor and the second sensor, the degree of supercooling of the condensed liquid refrigerant increases and the cooling capacity is improved, and at the same time, the degree of superheating at the outlet of the evaporator is reduced. Even in the ideal state of 0, heat is exchanged at the joint, and the degree of superheating of the temperature difference that can sufficiently absorb sensor variations can be set arbitrarily.

[Brief explanation of drawings]

FIG. 1 is a refrigeration cycle diagram of an air conditioner according to an embodiment of the present invention, and FIG. 2 is a refrigeration cycle diagram of a conventional air conditioner. 1... - Compressor, 2... Condenser, 3...
...Electric expansion valve, 4...Evaporator, 5...
...refrigerant pipe, 6...outlet section, 1o...
・First sensor, 12...Second sensor, 14
・・・・・・Connecting part.

Claims (1)

[Claims] A compressor, a condenser, an electric expansion valve, and an evaporator are connected in a ring with a refrigerant pipe to form a refrigeration cycle, and a refrigerant pipe is connected between an outlet of the evaporator, the condenser, and the electric expansion valve. a first sensor for detecting the temperature of a refrigerant pipe between the joint and the compressor; the temperature detected by the first sensor and the evaporator or evaporator; An air conditioner configured to control opening and closing of the electric expansion valve according to a temperature difference between the electric expansion valve and a second sensor that detects the temperature of the inlet.