JPS63197853A - Refrigerant circuit for heat pump type 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 Application Field] The present invention relates to a refrigerant circuit for a heat pump type air conditioner whose purpose is to expand the installation conditions and operating range of the air conditioner.

[Conventional technology]

FIG. 6 is a refrigerant circuit diagram of a conventional heat pump type air conditioner Sakaki disclosed in, for example, Japanese Utility Model Application Publication No. 59-4921. (1) is the compressor, (21 is the four-way valve, 13I is the outdoor heat exchanger, (5a) is the first check valve that passes the cold tube during cooling operation, and is installed on the outlet pipe side of the outdoor heat exchanger (31). be.

(5b) is an 8g2 check valve that passes refrigerant during heating operation, and is installed on the outlet pipe side of the indoor heat exchanger (7). (6a) is the second capillary for heating, (6b) is the first capillary for cooling, (7) is the indoor heat exchanger, ci+n is the first connection pipe,
t2X5 is the second connection pipe, and there are couplings at both ends to connect the inner and outer machines respectively! A refrigerant circuit is formed.

Next, to explain the operation, during cooling, the high-pressure gas refrigerant discharged from the compressor (1) passes through the four-way valve (2) and enters the outdoor heat exchanger (3), where it becomes a high-pressure quasi-refrigerant.
It passes through the reverse valve (5a), passes through the first connection pipe 0I+, is guided to the @ side of the pipe, is depressurized by the first cooling capillary (6b), and is evaporated and gasified in the indoor heat exchanger (7). This constitutes a cycle that passes through the second connecting pipe and returns to the compressor (1) via the four-way valve +21.

On the other hand, during heating, the four-way valve (2) switches to perform a cycle opposite to that during cooling.

[The balance that the invention attempts to solve]

The refrigerant circuit of a conventional heat pump type air conditioner is configured as described above, so both indoor and outdoor connection piping (inside 21+ is in a liquid state and the specific weight of the refrigerant amount is 11ookg/-, so both indoor and outdoor connections are connected). If the installation location of the external unit is compromised, the piping will become longer and the amount of refrigerant required in the refrigerant circuit will naturally increase, resulting in fear of armpit pressure during preferential start-up or an increase in refrigerating machine oil circulating in the circuit. Adverse conditions such as The level of 1-weak air has become lower due to the reduction of the air blowing noise of the machine, which is due to insufficient capacity of the indoor heat exchanger which acts as an evaporator during cooling, and the indoor heat exchanger which acts as a compressor during heating. Problems such as high pressure increases occur due to insufficient capacity of the equipment.

In addition, in order to prevent freezing due to insufficient capacity of the indoor heat exchanger during cooling, and high pressure rise due to insufficient capacity of the indoor heat exchanger during heating, 1. There is a configuration in which the bypass valve (81) of the bypass path connecting the discharge pipe and suction pipe of the compressor (1) is opened to lower the discharge pressure of the compressor and increase the suction pressure.In this case, in order to increase the effectiveness If you increase the refrigerant bypass flow rate, the refrigerant bypass flow rate heard from the indoor unit will increase, and in order to prevent this sound, an even more complicated circuit will be required. There was a Zhao point.

This invention was made in order to solve the above-mentioned inconvenience, and to create an air conditioner that can lengthen the piping connecting the indoor and outdoor units and at the same time expand the operating range when the air volume of the indoor unit decreases. The purpose is to obtain.

[Means to solve the problem of begging]

This invention replaces the arrangement of the cooling capillary tube and the heating capillary tube in a conventional refrigerant circuit, and furthermore, a bypass path with a bypass valve is provided between the discharge pipe of the compressor and these two capillary tubes. It is something.

[Effect]

In the refrigerant circuit of the heat pump air conditioner in this invention, by replacing the arrangement of the cooling capillary tube and the EA shaft capillary tube, the inside of the connecting pipe becomes a low-pressure two-phase additive refrigerant, and the refrigerant amount ratio M amount is greatly increased. decreases to

[Examples of inventions]

An embodiment of the present invention will be described below with reference to the drawings.

In Figure 1, (1) is a compressor, (2) is a four-way valve, (
31 is an outdoor heat exchanger, C41 is an accumulator, (
5a) is a first check valve that opens during cooling and closes during heating;
What about 5b)? A second check valve that closes when the chamber is heated and opens when heating;
(6a) is the second capillary tube, (6b) is the first capillary tube, and the second check yf (5b) and the first capillary tube (6b) are inside the outdoor unit when cooling the outdoor heat exchanger f31. Connected in parallel to the outlet 91+1 piping to form a first parallel circuit C241,
The first check valve (5a) and the second capillary tube (6a) are connected in parallel in an indoor heat exchanger (71 outputs and 1llllll arrangement) in the indoor unit to form a second parallel circuit.

(7) is the indoor heat exchanger, an is the first connection pipe, @ is the second connection pipe, ■ is the connection between the discharge pipe side of the compressor +11 and the first parallel circuit 241 and the second parallel circuit ■ A bypass valve (81) is provided in the middle of the bypass path.

Next, we will discuss the effects during cooling and heating.
The high pressure gas refrigerant discharged from the compressor (11) is passed through a four-way valve (
21 and enters the outdoor heat exchanger 131, where it becomes a high-pressure liquid refrigerant and is depressurized in the first capillary tube.

A low-pressure two-phase refrigerant is guided to the indoor unit through the first connection pipe r2D that connects the indoor and outdoor units. Furthermore, the first check valve (5a
), evaporates in the indoor heat exchanger (7), and the low-pressure gas coolant passes through the second connection pipe again and returns to the outdoor unit through the four-way valve (2).
), a cycle 1kw4 returns from the accumulator +41 to the pressure mm (s). Here the accumulator (4
1 has the function of storing surplus refrigerant generated due to operating conditions.

On the other hand, during heating, the high-pressure gas refrigerant discharged from the compressor fil passes through the four-way valve (21, second connection pipe ■), enters the indoor heat exchanger (71), is standardized here, and is depressurized by the second capillary tube. The refrigerant passes through the first connection pipe QII as a low-pressure two-phase flow refrigerant, returns to the outdoor unit, passes through the second check valve (5b), enters the outdoor heat exchanger (3), and evaporates here.

The compressor (
Construct a cycle that returns to 1).

In the refrigerant circuit configured as described above, the relative softness with respect to the conventional refrigerant circuit will be explained with reference to Table 12 and the characteristics diagram of the required refrigerant amount shown in FIG.

Here, the formula of the average specific weight of two-phase flow was used for the specific weight.

That is.

γG: Saturated gas ratio γL: Cell hydration ratio ■Quantity In Table 1, the liquid pipe specific weight was 401 kg/- for both the conventional circuit during cooling and the circuit of this invention, but in the conventional circuit during heating. 1100 kg/rrl, and in the circuit of this invention, it becomes 400 kg/-.

Looking at the specific softness on the refrigerant circuit shown in Table 2, at 1 g pipe internal pressure, the conventional circuit has a low value during cooling and high value during heating, while the circuit of the present invention has a low value during both cooling and heating.

In addition, the state of the refrigerant in the secondary pipe g is a two-phase flow during cooling in the conventional circuit and a subcooled liquid state during heating, but in the circuit of this invention, it is in a two-phase stagnation state during both cooling and heating. becomes.

Furthermore, if we look at the refrigerant t required for unit pipe length.

Conventional circuit cooling: 20f/lrL, heating: 6597
m, and when the circuit of this invention is cooling and heating, it is 20
f/fi.

Table 1 Table 2 In this way, in conventional refrigerant circuits, the first
The high-pressure liquid in the connecting pipe becomes a low-pressure two-phase refrigerant, making it cold! The amount of refrigerant in the refrigerant pipe decreases by a large amount to 1100 kg/- F400 kg Z-, and the amount of refrigerant required in the refrigerant piping decreases.Furthermore, if the bypass valve +H+ of the bypass path is opened, the air conditioner will be cooled. 1) tlf for both time and heating
18 Refrigerant or evaporator Mine internal/external heat exchanger f71 f31
supplied to the population. This is a so-called hot gas bypass operation, which prevents the internal heat exchanger, which is the evaporator, from freezing during cooling, and reduces the discharge pressure by reducing the evaporation capacity during heating. In either case, compressor f11
It is more effective than bypassing from exhalation to inhalation.

FIG. 2 shows an example of controlling the bypass valve (8), in which (9I is the power supply, (l[ is the cooling/heating changeover switch, aυ
is a temperature controller that detects the outside air temperature, and has a cooling stage,
For example, if the outside air is 25 or lower during cooling, and the outside air is 10 or higher during heating, the bypass valve +81 is reversely energized, causing freezing during cooling, Prevents discharge pressure from increasing during heating.

Moreover, FIG. 3 is an example of a Tsukuda which shows the timing of opening and closing of the bypass valve +81, where aZ is a low pressure switch that closes when the pressure rises, (131 is a high pressure switch that closes when the pressure rises).

In this case, the low pressure switch tI21 is attached to the suction pipe of the compressor fl), and the high pressure switch f+3 is attached to the discharge pipe of the compressor (1) to detect the refrigerant pressure. That is, during cooling, when the suction pressure decreases and the internal heat exchanger is about to collapse, the low pressure switch az closes and the bypass valve +81 is closed to prevent frost formation. Also.

During heating, when the discharge pressure increases as the indoor and outdoor temperatures rise, the high pressure switch 1131 closes.

This opens the bypass valve +81 to prevent the refrigerant pressure from rising abnormally.

〔Effect of the invention〕

As described above, according to the present invention, a cooling capillary tube is provided in the cooling outlet 9IiJ piping of the Mine outdoor heat exchanger, and a heating capillary tube is provided in the heating outlet side piping of the indoor heat exchanger. A refrigerant circuit that connects the compressor discharge pipes with a bypass path with a bypass valve to reduce the amount of refrigerant required in the refrigerant circuit, and at the same time allows a simple circuit to follow the load reduction during cooling @ air conditioning. This has the great effect of increasing the allowable piping length and expanding the operating range in which the installation conditions of air conditions can be relaxed.

[Brief explanation of the drawing]

Fig. 1 is a refrigerant circuit diagram of a heat pump type air conditioner showing one embodiment of the present invention, Fig. 2 is an electric circuit diagram showing control of a bypass valve, and Fig. 3 shows another embodiment of Fig. 2. Electrical circuit diagram, Fig. 4 is a temperature characteristic diagram of Fig. 2, Fig. 5 is a characteristic diagram showing the relationship between the required refrigerant amount and the conventional circuit, Fig. 6 is a refrigerant circuit diagram showing a conventional example, Fig. 7 The figure is a main part circuit diagram when a bypass path is added to the circuit in Figure 6. The same reference numerals in Figure 9 indicate the same or equivalent parts, (1
) is a compressor, (21 is a four-way valve, (31 is an outdoor heat exchanger, (5a) is a first check valve, (5b) is a second check valve,
(6a) is the second capillary tube, (6b) is the first capillary tube, (7) is the indoor heat exchanger, (Tear is the bypass valve, (23)
The bypass The 241 C is the first parallel circuit, and C151 is the second parallel circuit.

Claims (1)

[Claims] In a heat pump refrigerant circuit that connects a compressor, four-way valve, outdoor heat exchanger, throttling mechanism, indoor heat exchanger, four-way valve, etc., the outlet side piping of the outdoor heat exchanger is closed during cooling and closed during heating. A first parallel circuit in which a second check valve that opens and a first capillary tube are provided in parallel; and a first check valve that closes during heating and opens during cooling in the outlet side piping of the indoor heat exchanger during heating. and a second parallel circuit in which a second capillary tube is provided in parallel, and a bypass path having a bypass valve connecting the compressor discharge pipe and the first and second parallel circuits. A refrigerant circuit for a heat pump type air conditioner.