JPS6189456A - Refrigerating 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 [Field of Application of the Invention] The present invention relates to a refrigeration and air conditioning system, and particularly to refrigerant flow rate control.

[Background of the invention]

FIG. 8 shows a refrigeration cycle system diagram of a conventional refrigeration and air conditioner. In the figure, 1v'i is a compressor, 2 is a condenser,
8 is an electronically controlled expansion valve, 4 is an evaporator, 5 is a bypass circuit connecting the high pressure side refrigerant liquid pipe and the compressor suction side, 6 is a pressure reducer provided in the bypass circuit 5, and 7 is the saturation temperature of the suction pressure. 8 is a suction temperature detector provided between the evaporator outlet and the compressor suction port, and 9 is a controller, which detects the temperature from the suction temperature detector 8 and the saturation temperature detector 7. The valve opening degree of the electronically controlled expansion valve 8 is adjusted so that the difference in temperature, ie, the degree of superheating, is constant. The device purchased in this way is provided with a bypass circuit 5 to detect the degree of saturation, and the refrigerant liquid at the outlet of the condenser is quietly depressurized and bypassed to the suction side as a two-phase flow. Therefore, there is a disadvantage that the flow rate of refrigerant flowing to the evaporator side is reduced by the bypass flow amount, and the refrigerating capacity is also reduced.

On the other hand, as a method for detecting the degree of superheating of suction refrigerant,
There is also a method of detecting the difference between the evaporator outlet temperature and the inlet temperature as shown in Japanese Patent No. 127058, but in this case Kid
The degree of overmaturity can be accurately detected based on the pressure loss inside the evaporator, the pressure loss in the piping from the evaporator outlet and outlet to the compressor port, and the absorption of heat from the outside air.

In addition, in the above two examples, if the degree of superheating is set to a small value, for example 2 degrees, in order to use the generator effectively, a signal of the magnitude of 2 degrees will be generated even if the liquid returns. Therefore, it is necessary to set a large degree of superheat.

As a result, a part of the evaporator becomes overheated, resulting in a reduction in refrigerating capacity.

[Purpose of the invention]

The object of the present invention is to overcome the problems of the prior art.

To provide a refrigeration air conditioner that does not require a bypass circuit, can effectively utilize an evaporator, can accurately detect the degree of superheat, and can obtain a large signal of the degree of superheat.

[Summary of the invention]

In order to achieve this object, the present invention exchanges heat between the low-pressure refrigerant and the high-pressure side high-temperature refrigerant from the evaporator outlet to the compressor inlet in the refrigeration cycle, and also provides low-pressure refrigerant before and after the heat exchange section. The valve opening and closing of the electronically controlled expansion valve is adjusted by detecting the temperature difference between the side refrigerants.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure shows a refrigeration cycle system diagram of the refrigeration and air conditioner according to the present invention. In the figure, this refrigeration air conditioner includes an E-compressor 1'1, a condenser 12, an electronically controlled expansion valve 18, and an evaporator 14.
A refrigeration cycle is purchased by connecting the pipes in that order. Further, the refrigerant in the compressor discharge section and the refrigerant in the compressor suction section are configured to exchange heat in a heat exchange section 15. In addition, a first temperature detector 16 and a second temperature detector 17 are provided before and after the heat exchanger 15 to detect the temperature of the low-pressure refrigerant, respectively, and detection signals from both temperature detectors 16 and 17 are provided. is manually input to the controller 18. The controller 18 sets the difference between the temperature detected by the first temperature detector 16 and the temperature detected by the second temperature detector 17 as the degree of superheat, and sets the degree of superheat to be a set value. The opening degree of the electronically controlled expansion valve 18 is adjusted accordingly.

Next, the operation of this embodiment will be explained.

The refrigerant discharged from the compressor 11 is cooled by exchanging heat with a low-temperature refrigerant to be described later in the heat exchange section 16, and then flows into the condenser 12. - On the other hand, the low-temperature refrigerant that has exited the evaporator 14 is transferred to the heat exchange section 15
The refrigerant is heated by exchanging heat with the high-temperature refrigerant, and is sucked into the compressor 11. The relationship between the degree of superheating of the refrigerant before and after the heat exchange section 15 is as shown in FIG. That is, the degree of superheat of the refrigerant at the outlet of the evaporator is small, but the degree of superheat is large at the suction side of the compressor. In this embodiment, the temperature of the refrigerant in the heat exchanger 15#11 is detected by the first and second temperature detectors 16.17, and the controller 18 determines the temperature difference as the degree of superheat. Adjust the valve opening of the electronically controlled expansion valve 13 so that it reaches the set value. 7 The refrigerant flow rate is controlled by the electronically controlled expansion valve 18.

As described above, according to this embodiment, there is no need to provide a bypass circuit and the degree of superheating at the outlet of the evaporator can be reduced, so the evaporator can be used effectively and efficient operation can be achieved. Furthermore, since the detection of the degree of superheat is not affected by pressure loss, efficient operation can be achieved even in the case of a device with long connecting piping, such as a pub cage type air conditioner. Furthermore, since the superheat degree signal can be amplified and made larger, the controllability of the valve opening degree is improved.

In this example, heat exchange is performed between the refrigerant from the compressor discharge section to the condenser intake section and the refrigerant from the evaporator outlet section to the compressor suction section. A similar effect can be obtained by exchanging heat with the refrigerant from the evaporator outlet to the compressor outlet. It goes without saying that similar effects can be obtained by exchanging heat between the refrigerant liquid from the condenser outlet to the expansion valve port and the refrigerant from the evaporator outlet to the compressor inlet. Further, in the present invention, the heat exchange = il
This effect can be obtained if the refrigerants on the high-pressure side and the low-pressure side of the lOVi are in a heat exchange/exhaust relationship, and the structure thereof is not particularly limited.

〔Effect of the invention〕

As explained above, according to the present invention, there is no need to provide a bypass circuit, and the evaporator can be effectively utilized. f
It is possible to accurately detect the degree of superheating and obtain a large signal of the degree of superheating.

[Brief explanation of the drawing]

Fig. 1 is a refrigeration cycle system diagram showing an embodiment of the refrigeration and air conditioning system of the present invention, Fig. 2 is a diagram showing the relationship between the degree of superheating of the refrigerant before and after the heat exchange section in Fig. It is a refrigeration cycle system diagram showing a refrigeration air conditioner. 11...! E-compressor 12... Condenser 18... Electronically controlled expansion valve 14... Evaporator 15... Heat exchange section 16... First temperature detector 17... Second temperature detector 18...Controller. ’$3 Figure Fukan Jun

Claims (2)

[Claims] 1. A refrigeration cycle is constructed by sequentially connecting a compressor, condenser, electronically controlled expansion valve, and evaporator, and the low-pressure side refrigerant between the evaporator outlet and the compressor suction is connected to the electronically controlled expansion valve. A first temperature detector and a second temperature detector are provided at the inlet and outlet of the heat exchanger, respectively, and the first and second temperature detectors are provided at the inlet and outlet of the heat exchanger. A refrigeration and air conditioning system characterized by being provided with a leg restrainer that adjusts the opening degree of the electronically controlled expansion valve in accordance with a signal from a temperature detector. 2. The valve opening degree of the electronically controlled expansion valve is adjusted so that the difference between the temperature detected by the first temperature detector and the temperature detected by the second temperature detector becomes a set value. A refrigeration and air conditioning system according to claim 1.