JPH01155153A - Air conditioner - Google Patents

Abstract

PURPOSE: To ensure a stabilized heating effect by providing a bypath for circulating refrigerant by coupling the delivery side of a compressor with the suction side thereof or the cylinder of a compressor when the temperature of the compressor is lower than a specified level at the time of heating operation thereby the delivery temperature of refrigerant from the compressor at a high level. CONSTITUTION: A timer 26 is actuated when a compressor 16 is turned on at the time of heating operation and delivery temperature θof refrigerant from the compressor 16 is compared with a set level θ1 upon elapsing a predetermined time t0 . A two-way valve 23 is opened if θ<=θ1 and a part of high pressure high temperature refrigerant on the delivery of the compressor 16 is circulated to the suction side thereof with the flow rate being regulated by a capillary tube 24. Since low pressure low temperature refrigerant from an evaporator 20 and high pressure high temperature refrigerant from a bypath 22 are supplied to the suction side of the compressor 16, temperature of refrigerant being delivered from the compressor 16 increased as compared with the case when the bypath 22 is closed. Consequently, high temperature air can be blown out without decreasing the air volume and a good indoor temperature distribution can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an air conditioner, and particularly to an air conditioner that can increase the heat radiation energy of a condenser.

(Prior art) Conventionally, air conditioners mainly use a compressor l as shown in Figure 8.
, a condenser 3, an expansion valve 5 which is a pressure reducing device, an evaporator 6, and a pipe 12 connecting these in sequence. The Mollier diagram is shown in FIG. The enthalpy difference 10 between 8 and 9 in the Mollier diagram (A) indicates the heat radiation energy of the condenser 3. Note that 11 is a saturated liquid line.

(Problem to be Solved by the Invention) However, in conventional air conditioners, the heat radiation energy of the condenser 3 depends on the temperature of the refrigerant discharged from the compressor 1 when the amount of refrigerant circulation is approximately constant. If the refrigerant temperature was low, the temperature of the air blown from the condenser 3 could not be increased.

Also, in the case of a radiant air conditioner, if the discharge gas temperature is low, the temperature of the radiant surface cannot be increased.

In the case of the former type of air conditioner, in order to increase the temperature of the blown air, it is sufficient to reduce the amount of air passing through the condenser 3, but as the amount of air passing through decreases, the reach range of hot air is reduced, the temperature distribution deteriorates, etc. heating capacity decreases. At the same time, there is a risk that the life of the compression n1 will be shortened due to a significant increase in low temperature and high pressure within the refrigeration cycle.

In addition, in the case of a variable capacity air conditioner, the discharge refrigerant temperature is low during low volume operation, so if comfort is prioritized, maximum air volume operation cannot be performed. unable to perform its functions.

The present invention has been made in consideration of the above circumstances, and by increasing the temperature of the refrigerant discharged from the compressor, the heat dissipation energy of the condenser can be increased, a stable heating effect can be achieved and ensured, and the air conditioner can be operated for a long time. The purpose is to provide air conditioners that can extend their service life.

[Structure of the invention] (Means for solving the problems) In order to achieve the above object, the present invention includes a compressor, a condenser,
A compressor that transfers heated refrigerant to a condenser when the temperature of the mud compressor is less than a predetermined value during heating operation is used in an air conditioner formed by sequentially connecting a pressure reducing device and an evaporator to form a refrigerating cycle. A bypass passage is formed by connecting the discharge side and the suction side or the cylinder of the compressor and circulates the refrigerant to raise the temperature of the discharged refrigerant.

(Function) The bypass passage branches off from the discharge side of the compressor and is connected to the suction side or the cylinder of the compressor. During heating operation of the air conditioner, if the temperature of the compressor is below a predetermined value, a portion of the high temperature refrigerant pressurized by the compressor is returned to the suction side of the compressor or to the cylinder of the compressor. The returned high-temperature refrigerant and low-temperature refrigerant from the evaporator are then supplied to the compressor. As a result, the temperature of the refrigerant on the suction side of the compressor increases by 1, and the temperature of the refrigerant on the discharge side of the compressor rises by 1.
rise

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 shows an example of an air conditioner according to the present invention.

1 is a block diagram of an air conditioner 15 (hereinafter referred to as "air conditioner").

As shown in the figure, the basic parts of the air conditioner 1a15 during heating operation are substantially the same as in the conventional example, including a compressor 16, a four-way valve 17, and a four-way valve 17.
, 'a, consists of a compressor 18, a pressure reducing device, such as an expansion valve 19, an evaporator 20, and a pipe 21 connecting these in sequence. A bypass passage 22 connected to the side, a two-way valve 23 that is an on-off valve that opens and closes the bypass passage 22, a capillary tube 24 that is provided downstream of the two-way valve 23 and adjusts the amount of refrigerant passing through, and a refrigerant discharged from the compressor 16. A temperature sensor 25 that detects temperature, a timer 26 that starts at the same time as the air conditioner 15 starts operating, and a two-way valve 23 that opens and closes based on the time t measured by this timer 26 and the temperature θ detected by the temperature sensor 25. Valve control means 27 are provided for controlling.

The valve control means 27 is configured to carry out control as shown in the flowchart of FIG. 2 in detail. That is, when the compressor 16 is turned on (step 51), the timer 2
6 is started (step 52), and timer 2
6 is less than a predetermined time to, for example, one minute (step 53), and the three-way valve 23 remains closed until the former becomes equal to the latter (step 54), the predetermined time to After the elapsed time, the discharge cools as detected by the temperature sensor 25! The j actuated to open (step 56), otherwise the two-way valve 23 remains closed (step 57); after step 56, return to step 55;
The discharge refrigerant temperature θ and the first set value θ1 are compared, but after step 57, the discharge refrigerant temperature θ is set to another set value θ2 lower than the first set value θ1, for example, 60°C (hereinafter referred to as the "second set value θ1"). ''), the two-way valve 23 remains closed until the second set value θ2 is reached.

The reason why the two-way valve 23 is closed until a predetermined time to has elapsed after the start of the compressor 16 is because the pressure inside the pressure mtra is low immediately after the start of the compressor 16, especially in rotary compressors, the blades are closed. This is because jumping is likely to occur due to insufficient back pressure, which may result in poor compression or abnormal noise. If the two-way valve 23 is opened at the same time as the compression fi 16 is started, the above-mentioned problem is likely to occur, and the two-way valve 23 is closed to close the bypass passage 22 for about one minute after the compressor 16 is started.

The reason why the two-way valve 23 is once closed based on the first set value θ1 and then controlled to open and close based on the second set value θ2, which is smaller than the first set value θ1, is because the opening and closing operations of the two-way valve 23 are frequently performed. This is to prevent this from happening, and this allows for smooth air conditioner control. Specifically, as shown in Figure 3, the first set value θ1 is set to 70°C, and the second set value θ2 is set to 60°C.
There are also examples of hysteresis.

Next, the operation when the air conditioner R15 configured as above is operated for heating will be explained.

When the pressure ff111'l16 is turned on, the timer 26 is started as explained based on the flowchart of FIG. 2, and the three-way valve 23 is closed until the predetermined time to is reached. After the predetermined time to has elapsed, the temperature θ of the refrigerant discharged from the compressor 16 is compared with the first set value θ1, and if θ≦01, the two-way valve 23 is opened. When the two-way valve 23 is opened, a portion of the high temperature refrigerant at the discharge pressure on the discharge side of the compression fi16 is circulated to the suction side of the compression a16. At this time, the flow rate of the refrigerant being circulated is adjusted by the capillary tube 24. Therefore, pressure 1
The suction side of a11116 is supplied with a low-pressure, low-temperature refrigerant sent from the evaporator 20 and a high-pressure, high-temperature refrigerant whose flow rate is adjusted and which comes via the bypass passage 22.

As a result, the refrigerant discharged from the compressor 16 has a higher temperature than when the bypass passage 22 is closed. FIG. 4 shows a comparison between the Mollier diagram (B) at this time and the conventional Mollier diagram (^).

In the Mollier diagram (B), although the amount of refrigerant circulation decreases somewhat, the heat exchange efficiency of the condenser 18, which is a heat exchanger, increases, so the heat radiation energy of the condenser 18 increases from the conventional 10 to 2.
Increased to 9.

Therefore, in this embodiment, since the two-way valve 23 is closed until the predetermined time to has elapsed after the compression fi 16 is started, there will be no compression failure or abnormal noise.

Furthermore, the temperature of the refrigerant discharged from the compressor 11116 can be increased to increase the heat radiation energy of the condenser 18. This makes it possible to blow out high-temperature air without reducing the air volume, resulting in a good indoor temperature distribution.

Furthermore, the opening and closing of the two-way valve 23 can be controlled smoothly.

In addition, since the inside of the refrigeration cycle is prevented from becoming low temperature and high pressure, the life of the air conditioner 1fi15 can be extended.

In the above embodiment, the opening and closing of the two-way valve 23 depended on the temperature of the refrigerant discharged from the compressor 16, but the surface temperature of the compressor a16 may be input to the valve control means 27.

Further, the capillary tube 24 may not be provided in the bypass passage 22, and instead of the two-way valve 23, a valve whose opening degree can be changed, such as an electronic expansion valve, may be provided.

Furthermore, if opening the bypass passage 22 at the same time as the start of the compressor 16 does not cause problems such as poor compression or abnormal noise, the timer 26 is not provided and the temperature θ of the discharged refrigerant is set to the first level at the same time as the start of the compressor 16. It may also be compared with the set value θ1. In other words, steps 52 to 54 in the flowchart of FIG. 2 may be omitted.

In addition, in radiant air conditioners, air conditioners with variable capacity compressors, and injection air conditioners, the amount of refrigerant circulation does not decrease or can be maintained by increasing the rotation speed, so the above-mentioned effects and effects are achieved. You can expect it.

This is particularly effective for radiant air conditioners that require high temperatures in certain areas.

In addition, if the compressor is a variable capacity air conditioner, a Mollier diagram such as C shown in Figure 5 will be obtained, and even if the allowable pressure of the refrigeration cycle is at the upper limit, high temperature air blowing due to high temperature refrigerant and high temperature radiation becomes possible. In the case of the same air conditioner,
During stable operation, if the room temperature rises and the pressure m function decreases, the sensible temperature may also drop, so the temperature of the discharged refrigerant may be 6.
The bypass passage is opened when the temperature drops below 0°C.

Furthermore, as shown in FIG. 6, in the injection air conditioner 30, refrigerant is supplied from the discharge side into the cylinder of the compressor 16 during the compression stroke, but in this case, the capillary tube is normally Not necessary. As shown by D in FIG. 7, this Mollier diagram makes it possible to maintain the heating capacity and provide high-temperature discharge refrigerant even if the capacity is not variable. Note that two of them are radiation surface temperature sensors.

[Effects of the Invention] In summary, the present invention provides the following excellent effects.

When the temperature of the refrigerant discharged from the compressor is lower than the set value, the high temperature discharged refrigerant can be circulated to the suction side or the cylinder of the compressor via the bypass passage, so the temperature of the suction refrigerant can be increased, and this makes it possible to increase the temperature of the discharged refrigerant. The temperature rises and it becomes possible to blow hot air out of the condenser.

[Brief Description of the Drawings] Fig. 1 is a block diagram of an air conditioner as an embodiment of the air conditioner according to the present invention, and Fig. 2 is a valve control diagram of the air conditioner shown in Fig. 1. Flowchart to explain the method
1, Fig. 3 is a diagram explaining the control of the two-way valve shown in Fig. 1, Fig. 4 is a Mollier diagram of the conventional structure and the air conditioner shown in Fig. 1, and Fig. 5 is a diagram explaining the control of the two-way valve shown in Fig. 1. Mollier diagrams of other embodiments and conventional structures, FIG. 6 is a block diagram of an injection type air conditioner as another example of Tenkata noodles of the present invention, and FIG. 7 is a conventional structure and the air conditioner of FIG. 6. FIG. 8 is a block diagram of a conventional till structure, and FIG. 9 is a Mollier diagram of FIG. In the figure, 15 is an air conditioner, 16 is a compressor, 18 is a condenser, one is an expansion valve which is a pressure reducing device, 20 is an evaporator, and 22 is a bypass passage. Representative Patent Attorney Nori Chika Ken
Hiroshi Uji Figure 3 Figure 4 Figure 5 Figure 9

Claims (4)

[Claims] (1) In an air conditioner formed by sequentially connecting a compressor, condenser, pressure reducing device, and evaporator to form a refrigeration cycle,
A bypass is formed by connecting the discharge side of the compressor and the suction side or the cylinder of the compressor, which transfers the heated refrigerant to the condenser when the temperature of the compressor is less than a predetermined value during heating operation, and circulates the refrigerant. An air conditioner characterized by providing a passage to increase the temperature of discharged refrigerant. (2) The air conditioner according to claim 1, wherein the temperature of the compressor is the temperature of the refrigerant discharged from the compressor. (3) The air conditioner according to claim 1, wherein the temperature of the compressor is a surface temperature of the compressor. (4) The air conditioner according to claim 1, wherein an on-off valve is provided in the bypass passage, and the on-off valve is controlled to open after a predetermined time has elapsed after the compressor is started.