JPH08121879A - Refrigerating and air conditioning apparatus - Google Patents

Abstract

PURPOSE: To control high pressure by providing a compressor, a condenser, a throttle and an evaporator in a refrigerating and air conditioning apparatus, and providing an automatic inlet pressure regulating valve in parallel with the throttle. CONSTITUTION: Refrigerant gas output from a compressor 1 is introduced to a condenser 2, radiated and liquefied. Refrigerant liquefied by the condenser 2 is all fed through a capillary tube 3 of the throttle, pressure-reduced, introduced to an evaporator 4, evaporated and vaporized, and returned to the compressor 1 to complete a refrigerating cycle. In this case, an automatic inlet pressure regulating valve 6 is provided in parallel with the tube 3 of the throttle, and the valve 6 is opened when the condensing pressure is raised as the atmospheric temperature rises and the raised pressure rises to a set pressure. Thus, the high pressure can be held substantially constantly to avoid excess pressure rise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating / air conditioning system.

[0002]

2. Description of the Related Art FIG. 5 is a refrigerant circuit diagram of a refrigerating machine in which an opening / closing valve is provided in parallel with a main throttle to control a refrigerant flow rate.
This is disclosed in JP-A-2-290471.
In the figure, 1 is a compressor, 2 is a condenser, 4 is an evaporator, 1
Reference numeral 1 is a first capillary tube, 12 is a second capillary tube, 13 is a bypass circuit provided in parallel with the first capillary tube, 14 is an opening / closing valve provided in the circuit, and 15 is a compressor rotation speed control. Reference numeral 16 is a rotation speed comparing means, 17 is an operating time comparing means, 18 is an opening / closing valve controlling means, 19 is a temperature detecting means, and 20 is a temperature comparing means.

This circuit controls the on-off valve 14 to perform a stable operation by detecting the rotation speed of the compressor, that is, the refrigerant circulation amount and the discharge gas temperature, and by the return condition of the liquid refrigerant that can be indirectly determined. It's about to get. Such a circuit adjusts the flow rate of the first capillary tube 11, which is a fixed throttle, when the operating temperature range is wide. That is, by using the bypass circuit 13, it is possible to open the on-off valve 14 and reduce the high pressure when the high pressure is extremely high, for example. Since the operation of the parts other than the above is known, the description thereof will be omitted.

[0004]

In the circuit shown in the above-mentioned prior art, that is, the circuit for bypassing the capillary tube by using the on-off valve, there are the following problems when high pressure control is performed. (1) In addition to the need for a pressure switch for detecting high pressure, electrical wiring is required. (2) Since the flow rate changes stepwise by the opening / closing operation of the valve, it is necessary to increase the number of combinations of the opening / closing valve and the capillary tube in order to lower the pressure more than necessary and to widen the appropriate range.

The present invention solves the above-mentioned drawbacks of the prior art and makes it possible to control high pressure by a simple device.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and in a refrigerating / air-conditioning apparatus equipped with a compressor, a condenser, a throttle, and an evaporator, an automatic inlet pressure adjustment is provided in parallel with the throttle. The present invention relates to a refrigerating / air-conditioning device having a valve.

[0007]

Since the refrigerating / air-conditioning apparatus of the present invention is configured as described above, the pressure on the inlet side of the throttle becomes high, and when the set pressure of the inlet pressure adjusting valve is reached, the valve will automatically open and the pressure will further increase. The higher the valve opens, the higher pressure can be kept almost constant and excessive pressure rise can be avoided.

[0008]

1 is a refrigerant circuit diagram according to a first embodiment of the present invention, which is an example in which the present invention is applied to a refrigerating apparatus. In the figure, 1 is a compressor, 2 is a condenser, 3 is a capillary tube, 4 is an evaporator, 5 is a bypass circuit provided in parallel to the capillary tube 3, and 6 is an inlet provided on the bypass circuit. It is a pressure control valve.

In the circuit of this embodiment, the high-temperature and high-pressure refrigerant gas that has exited the compressor 1 enters the condenser 2 and radiates heat to be liquefied. When the condenser 2 is of the air cooling type, the condensation pressure changes depending on the outside air temperature. Therefore, when the outside air temperature is not high, the condensation pressure is also low, and therefore the inlet pressure adjusting valve 6 is closed. As a result, all the refrigerant liquefied in the condenser 2 passes through the capillary tube 3, is decompressed here and enters the evaporator 4, takes heat from the surroundings, evaporates and vaporizes itself, and returns to the compressor 1 for the refrigeration cycle. Complete. As the outside air temperature rises, the condensing pressure, that is, the pressure at the inlet of the inlet pressure adjusting valve 6 rises. When this pressure rises to the set pressure of the inlet pressure adjusting valve 6, the inlet pressure adjusting valve 6 opens.

FIG. 2 is a sectional view of the inlet pressure adjusting valve 6 used in the above embodiment. In the figure, the main portion of the valve body is composed of a tubular body portion 21 extending in the vertical direction. In the lower part of the body portion 21, an inlet-side mouth 22 that extends downward and is connected to the bypass pipe 15 and an outlet-side mouth 23 that extends leftward are formed. A valve seat 24 is formed at the base end of the mouth 22. A valve body 25 that is combined with the valve seat 24 is accommodated in the body portion 21 that serves as a valve chamber. The lower end of the valve body 25 has a conical shape. At the upper end of the valve body 25, the coil spring 2
A spring retainer 27 is connected via 6. A screw shaft 28 projects from the center of the upper portion of the spring retainer 27. The screw shaft 28 is screwed into the upper wall of the body 21 so as to be able to move forward and backward, and the valve body 25 is positioned in the valve hole 24a formed in the valve seat 24. 30 is a cap. Then, by removing the cap 30 and adjusting the screw shaft 28 forward and backward, the coil spring 26 is displaced in the direction in which it is compressed, and the valve hole 24a is "opened" when the refrigerant pressure becomes equal to or higher than a predetermined high pressure. Then, the valve body 25 is pressed against the valve seat 24. As a result, the valve hole 24a is normally formed in the valve body 25.
When the refrigerant pressure becomes equal to or higher than a predetermined high pressure due to the close contact between the lower portion of the valve seat 24 and the valve seat 24, the valve body 25 is pushed up in the direction away from the valve seat 24 and opens. In addition, 29 is a locking nut screwed into the screw shaft end, 31 is a cap 30
It is a sealing member provided between the body and the body portion 21.

According to the above operation settings, when the refrigerant pressure becomes higher than a predetermined high pressure, the liquid refrigerant from the condenser 2 is added through the capillary tube 3 and the adjustment valve 6, and the evaporator is added. 4 and evaporate there. That is, as the high pressure increases, the valve opening of the adjusting valve 6 automatically increases, and the throttle including the capillary tube 3 becomes loose, so that the refrigerant easily flows and the high pressure becomes higher than a predetermined value. Can be avoided.

FIG. 3 is a refrigerant circuit diagram according to the second embodiment of the present invention, which is an example in which the present invention is applied to a heat pump type air conditioner. In the figure, 1 is a compressor, 40 is a four-way valve, 4
1 is an outdoor heat exchanger that is connected to the four-way valve 40 and has two circuits inside, 42a and 42b are distribution pipes that connect to each of the circuits, 43 is a cooling capillary tube, and 44
Is a check valve provided in parallel with the tube, and 6A is an inlet pressure adjusting valve provided in parallel with the tube. The structure of this valve is the same as that shown in FIG. Four
5 is a pipe connected to the capillary tube 43, the check valve 44, and the inlet pressure adjusting valve 6A, 46 is a heating capillary tube connected to the pipe, 47 is a check valve provided in parallel with the tube, and 6B is The inlet pressure adjusting valve is provided in parallel with the tube and has the same structure as that shown in FIG. The heating capillary tube 46, the check valve 47,
After joining the pipes connected to the inlet pressure adjusting valve 6B, the distribution pipe 4
It is divided into 8a and 48b. 49 is an indoor heat exchanger having two circuits inside, and the distribution pipe is connected to each circuit. The pipes connected to the indoor heat exchanger are joined and then connected to the four-way valve 40.

In the present circuit, during cooling operation, the four-way valve 40 is connected in the direction of the solid line, and the high-temperature and high-pressure refrigerant gas that has left the compressor 1 enters the outdoor heat exchanger 41 through the four-way valve 40, It radiates heat and liquefies. The liquefied refrigerant passes through the distribution pipes 42a and 42b, and the cooling capillary tube 43.
Leading to. Here, when the outside air temperature is not high, the condensation pressure is also low, and therefore the inlet pressure adjusting valve 6A is closed. Since the check valve 44 is also closed because the flow direction is opposite, all the liquefied refrigerant passes through the cooling capillary tube 43 and is depressurized there to enter the pipe 45. Most of the depressurized refrigerant passes through the check valve 47 because it opens, and enters the indoor heat exchanger 49 via the distribution pipes 48a and 48b. Here, heat is taken from the room air, and the air evaporates and vaporizes, returns to the compressor 1 through the four-way valve 40, and completes the refrigeration cycle.
During this time, if the pressure loss of the refrigerant in the indoor heat exchanger 49 becomes excessively large, the capacity deteriorates. Therefore, an air conditioner having a large capacity usually has multiple circuits. In order to adjust the amount of refrigerant flowing in each circuit, distribution pipes 48a and 48b are provided in each circuit. The distribution pipes 48a and 48b perform proper distribution to the low-pressure refrigerant, which is a two-phase flow, by having some resistance. Therefore, the pressure in the pipe 45 becomes higher than the evaporation pressure.

As the outside air temperature rises, the condensing pressure rises and the pressure at the inlet of the inlet pressure adjusting valve 6A rises. When this pressure rises to the set pressure of the inlet pressure adjusting valve 6A,
This inlet pressure adjusting valve 6A is opened. As a result, it is possible to almost avoid that the throttle including the cooling capillary tube 43 becomes loose, the refrigerant easily flows, and the high pressure becomes higher than a predetermined value. In this case, the pressure in the pipe 45 rises due to the opening of the inlet pressure adjusting valve 6A, and the distribution pipe 48
The portions a and 48b also easily flow. Therefore, the distribution pipe 4
It is avoided that the high pressure is determined in the portions 8a and 48b.

In the heating operation, the four-way valve 40 is connected in the direction of the broken line. Since the heat pump type refrigeration cycle is completely symmetrical in appearance, the flow of the refrigerant is the same as in the case of cooling. Therefore, when the high temperature becomes high, such as when the indoor temperature is high or when the amount of air flowing through the indoor heat exchanger 49 is reduced, the high pressure is opened to a predetermined value by opening the inlet pressure adjusting valve 6B. Will be kept. In this example, the inlet pressure adjusting valve is provided for both cooling and heating, but only one may be provided.

FIG. 4 is a refrigerant circuit diagram of a heat pump type air conditioner according to a third embodiment of the present invention. This is for cooling,
This is an example in which one inlet pressure adjusting valve is used for heating as well. In the figure, 1 is a compressor, 50 is a four-way valve, 51 is an outdoor heat exchanger, 52 is a cooling capillary tube, and 53.
Is a capillary tube for both cooling and heating, 54, 55, 5
Reference numerals 6 and 57 are check valves, and 58 is an indoor heat exchanger. In this circuit, during cooling, the refrigerant passes through both the cooling capillary tube 52 and the cooling / heating capillary tube. Capillary tube 5 for both cooling and heating during heating
Pass only 3 The inlet pressure adjusting valve 6C has the same structure as that shown in FIG. 2, is installed in parallel with these capillary tubes, and serves both for cooling and heating. The operation of this inlet pressure adjusting valve 6C in this circuit is the same as that in the second embodiment, and therefore its explanation is omitted. This example is an example in which the circuit configuration is simplified and has an effect of cost reduction.

[0017]

In the refrigerating / air-conditioning apparatus of the present invention, since the automatic inlet pressure adjusting valve is provided in parallel with the throttle, the high pressure can be automatically controlled by a simple device, and the cost can be reduced. effective.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an inlet pressure control valve used in the above embodiment.

FIG. 3 is a refrigerant circuit diagram according to a second embodiment of the present invention.

FIG. 4 is a refrigerant circuit diagram according to a third embodiment of the present invention.

FIG. 5 is a refrigerant circuit diagram of a conventional refrigeration system.

[Explanation of symbols]

1 Compressor 2 Condenser 3 Capillary tube (throttle) 4 Evaporator 5 Bypass circuit 6,6A, 6B, 6C Inlet pressure control valve 40 Four-way valve 41 Outdoor heat exchanger 42a, 42b Distribution pipe 43 Cooling capillary tube 44 Non-return Valve 45 Pipe 46 Heating capillary tube 47 Check valve 48a, 48b Distribution pipe 49 Indoor heat exchanger 50 Four-way valve 51 Outdoor heat exchanger 52 Cooling capillary tube 53 Cooling / heating capillary tube 54, 55, 56, 57 Reverse Stop valve 58 Indoor heat exchanger

Claims (1)

[Claims] 1. A refrigeration / air-conditioning system comprising a compressor, a condenser, a throttle, and an evaporator, wherein a refrigeration / air-conditioning system is provided with an automatic inlet pressure adjusting valve in parallel with the throttle.