JPH0148461B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an air conditioner, specifically, an air conditioner equipped with a fan, a heat exchanger serving as a condenser during heating, a capacity control means capable of controlling the capacity in stages, and a high pressure The present invention relates to an air conditioner that has a compressor equipped with a pressure switch and whose capacity can be adjusted. (Prior art) The present applicant has previously filed a patent application for an air conditioner configured as described above (Japanese Patent Application No. 1983-
No. 60454). The cooling capacity of the air conditioner according to this earlier application is controlled based on the temperature of the air blown from the fan, and as schematically shown in FIG. ), and a determining means 52 for comparing the detected temperature and the set temperature based on the outputs of these means 50 and 51. and a capacity control command means 53 for adjusting the capacity level of the compressor (not shown) having a capacity control means at predetermined time intervals (for example, 3 minutes) based on the output of the determination means 52. At this time, the capacity of the air conditioner is adjusted based on the output of the capacity control command means 53 at the predetermined time intervals, and the temperature of the blown air is maintained at the set temperature. However, the configuration shown in Figure 8, Figure 3
To explain with reference to the figure, during heating operation, due to a sudden decrease in the load of the air-conditioned room 20, the blow-off duct 19 connected to the blow-off side of the air conditioner
When the amount of air blown by the fan is drastically reduced, such as when the dampers 21 of the air-conditioned rooms 20 are simultaneously closed, the blowing pressure of the compressor increases and the temperature of the blown air may rise rapidly. Even though this occurs, the capacity step of the compressor cannot be reduced until the next output that is periodically output by the capacity control command means 53. Before the capacity step of the compressor is reduced by the output of 53, the discharge pressure of the compressor becomes higher than the set pressure of a high pressure switch (not shown) provided in the compressor, and the compressor There were cases where it was suspended. As a result, the frequency of starting and stopping of the compressor increases, which not only impairs the durability of the compressor but also makes it impossible to stably control the temperature of the blown air. (Object of the Invention) An object of the present invention is to provide, in addition to the above-mentioned determining means, a determining means for determining whether the discharge pressure has increased extremely rapidly and reached a high pressure in an unfavorable range based on the temperature of the blown air. , the refrigeration capacity is forcibly reduced at the same time as the output according to the output of the determination means, and when the compressor stops when the refrigeration capacity is forcibly reduced, the adjustment output is adjusted to the side where the capacity is reduced. By preventing the compressor from stopping and maintaining the current capacity level, the frequency of stopping the compressor due to the operation of the high-pressure switch is reduced, the durability of the compressor is improved, and the temperature of the blown air is stabilized. The point is to make it possible to control it. (Structure of the Invention) The structure of the present invention includes a heat exchanger that is equipped with a fan and serves as a condenser during heating, a capacity control means that can control the capacity in stages, and a compressor that is equipped with a high-pressure switch. an air conditioner having a detection means for detecting the temperature of the blown air, a first setting means for setting a set temperature of the blown air temperature, and based on each output of the detection means and the first setting means. a first determination means for comparing the detected temperature and the set temperature;
a second determination reference temperature that is higher than the set temperature set by the setting means and lower than the blowout air temperature corresponding to the set pressure of the high pressure switch;
a setting means, a second determination means for determining whether the detected temperature has reached the determination reference temperature based on the outputs of the second setting means and the detection means, and a predetermined period of time based on the output of the first determination means. capacity control command means for adjusting the capacity level of the compressor by one level each time, and simultaneously adjusting the capacity level of the compressor to the capacity decreasing side based on the output of the second determining means; The command means includes a capacity holding means that determines the capacity level and, when the compressor stops when the capacity is decreased by one level, prevents the adjustment output to the capacity decreasing side and maintains the current capacity level. If the temperature of the air blown out during heating operation rises rapidly and reaches the above-mentioned criterion temperature due to
The capacity control command means sets the capacity level of the compressor to the capacity decreasing side based on the immediate response output of the second determination means, which also separately provides a periodic output based on the output of the first determination means. The cooling capacity can be immediately adjusted to reduce the refrigerating capacity to suppress increases in the blown air temperature and the discharge pressure of the compressor, and further, the second
According to the output of the determination means, when the compressor is stopped by decreasing the capacity of the compressor by one step, the output of the capacity holding means prevents the adjustment output to the side of reducing the capacity, and The capacity level is maintained to prevent the compressor from stopping. (Example) Hereinafter, an example of the present invention will be described based on the drawings. First, the structure of the air conditioner of this example will be explained as follows.
An outline will be explained based on FIG. 3. In Figures 2 and 3, 1 is an indoor unit;
A and 1B are two outdoor units connected to the indoor unit 1. To describe the indoor unit 1 in detail, the unit 1 has two independent systems, the first,
The first and second refrigerant circuits are interposed in the second refrigerant circuits 2 and 3, respectively.
Compressors 4 and 5, first and second heat exchangers 6 and 7, and a fan 8 are installed inside. Further, the first and second compressors 4 and 5 are equipped with capacity control means having an unloader mechanism (not shown) and electromagnetic three-way valves 9 and 10 for operating the mechanism. Although it does not have 3 cylinders,
One of the cylinders is provided with an unloader mechanism (not shown) that connects electromagnetic three-way valves 9 and 10, and the three-way valves 9 and 10 are operated to selectively apply high and low pressure to the unloader mechanism. It is designed to allow capacity operation and partial capacity operation of 67% of the full capacity. Therefore, the first and second compressors 4,
By controlling the capacity or starting/stopping each of the compressors 5 and 5 separately, the total capacity of the compressors 4 and 5 can be adjusted to
Therefore, the refrigerating capacity of the air conditioner can be adjusted in five stages as shown in the table below.

[Table] In Fig. 2, 11 and 11 are the heat exchangers installed in the outdoor units 1A and 1B, respectively, and 13 and 1 are the heat exchangers installed inside the outdoor units 1A and 1B, respectively.
3 is a four-way switching valve; 14, 14 is an expansion mechanism for heating; 15, 15 is an expansion mechanism for cooling; 16, 16
1 is a check valve, 17, 17 is a liquid receiver, and 18, 18 is an accumulator. and the four-way switching valve 13
By this switching operation, the two refrigerant circuits 2 and 3 can form a heating cycle indicated by a solid line arrow and a cooling cycle indicated by a broken line arrow. Further, in FIG. 3, 19 is a duct that sends the air blown by the fan 8 to a plurality of air-conditioned rooms 20, 20, and 21 is a damper installed at the outlet of the air-conditioned rooms 20, 20, which is opened by the indoor load. It is designed so that the degree can be adjusted. Furthermore, 22 is a detection means for detecting the temperature of the air blown from the fan 8, and based on the temperature detected by the detection means 22, a control system (X) to be described later is operated to determine the refrigerating capacity at each step shown in Table 1. The temperature of the blown air is controlled to be constant. In the air conditioner constructed as described above, the control system (X) is constructed as shown in the block diagram of FIG. 1 in order to control the temperature of the blown air during heating operation. However, this control system (X) uses the above-mentioned detection means 22 for detecting the temperature of the blown air as a control input part, and the basic configuration of this control system (X) will be explained below: (a) Temperature of the blown air (b) A first setting means 23 for setting a set temperature (t ₀ ) of the blown air; (b) a detection temperature (t) of the blown air and a set temperature ( t ₀ ) first determination means 24 for comparing
and (c) setting a judgment reference temperature (t ₁ ) higher than the set temperature (t ₀ ) and lower than the blowing air temperature corresponding to the set pressure of the high-pressure pressure switches HPS-1 and HPS-2. (d) Based on the outputs of the second setting means 27 and the detection means 22, the detection means (t) determines and outputs that the determination reference temperature (t ₁ ) has been reached. (e) Based on the output of the first determining means 24, each of the compressors 4 and 5 is configured to increase or decrease the refrigerating capacity by one step or to maintain the same state at predetermined time intervals based on the output of the first determining means 24; While adjusting the capacity stage (step of refrigerating capacity) of the second determining means 2, the detected temperature (t) reaches the determination reference temperature (t ₁ ).
When the compressor 8 outputs an output, the capacity control command means 25 adjusts the capacity level of each of the compressors 4 and 5 to the capacity decreasing side in order to reduce the refrigerating capacity by one step at the same time as the output. Note that, hereinafter, the steps of the refrigerating capacity are simply referred to as capacity steps. In this example, the detected temperature (t)
When the compressor reaches the determination reference temperature (t ₁ ) and the second determination means 28 outputs an output, the capacity step (capacity step) is determined at the same time, and when the capacity step is decreased by one step from the current capacity step, the compressor When at least one of the compressors 4 and 5 is stopped, the capacity control command means 25 is made to maintain the capacity level (capacity step) of the compressors 4 and 5 at that time. In other words, capacity holding means 29 is provided to prevent the command means 25 from outputting an output to decrease the capacity step. Specifically, even if the second determining means 28 outputs an output, if the ability step at that time is the first or third step, that ability step is held. The reason for doing this is that when the detected temperature (t) reaches the judgment reference temperature (t ₁ ) in the first and third steps, the compressors 4,
When the capacity step is decreased by one step to the 0th and 2nd steps where both or one of the steps 5 and 5 are stopped,
For the former (transition to the 0th step), compressors 4 and 5 will eventually be completely stopped, and for the latter (transition to the 2nd step), compressors 4 and 5 will be completely stopped.
Regarding the transition to step), the second compressor 5 is stopped, and the first compressor 4 becomes 100% capacity, and receives residual heat from the condenser 7 of the second circuit 3 on the stopped side. This is because the high pressure in the first circuit 2 will rise further and the first compressor 4 may also stop, thus the meaning of reducing the capacity step will be lost. What is shown in Fig. 4 is the control system (X) described above.
It is an electric circuit diagram which carried out. In FIG. 4, 30 is a controller consisting of a microcomputer with a timer, which is shown in FIG.
The first and second determining means 24, 28, ability control command means 25, and ability holding means 29 described above are incorporated by a program. Further, on the input side of the controller 30, the detection means (hereinafter referred to as a detector) 22 for detecting the temperature of the blown air and the first setting means (hereinafter referred to as a first setting means) for setting the set temperature (t ₀ ) are provided. A second setting means (hereinafter referred to as a second setting device) 27 for setting the determination reference temperature (t ₁ ) is connected. Further, a capacity control output section 35 is connected to the output side of the controller 30 for controlling the output to the devices constituting each of the compressors 4 and 5, and the output section 35 operates the unloader mechanism. Each solenoid S ₁ , S ₂ of the electromagnetic three-way valve 9 , 10 , each compressor 4 , 5
It has switches C ₂ and C ₃ for starting and stopping control of the drive motors CM ₁ and CM ₂ . Further, on the input side of the controller 30, in addition to the detector 22, the first and second setting devices 23, 27,
Each of the high pressure switches HPS-1 and HPS-2, and each operation switch for heating and cooling PBS-1 and PBS
-2 is connected. Further, _C1 is a switch for controlling the start/stop of the motor FM of the fan 8 on the indoor side. The controller 3 shown in FIG.
This is a flowchart showing a program related to the heating operation used in No. 0, and the operation of the air conditioner during the heating operation will be explained based on this flowchart. In addition, during heating operation, the set temperature (t ₀ ) is set to 40℃,
Assuming that the judgment reference temperature (t ₁ ) is 41.5°C, _the temperature difference (Δt=
This temperature difference (Δt) is expressed as follows according to t−t ₀ ).
The area is divided into two areas, and area B below is the control area for the temperature of the blown air. (See Figure 7) Area A...Δt-4.5°C Area B...-4.5°C<Δt0°C Area C...0°C<Δt<1.5°C Area D...1.5°CΔt Also, the capacitance control output section 35 The relationship between the output state of the compressor and the refrigerating capacity step (the capacity step of the compressors 4 and 5) is shown in Table 2.

[Table] For each switch C ₂ and C ₃ , ON is the excited state, and the contacts of the switches C ₂ and C ₃ are closed and each motor is activated.
This indicates that the motors CM ₁ and CM ₂ are being driven, and OFF indicates that the motors CM ₁ and CM ₂ are stopped. Further, in the electromagnetic three-way valves 9 and 10, ON and OFF are respectively applied to the respective compressors 4 and 10.
5 partial capacity operation and full capacity operation are supported. When the heating operation switch PBS-2 is closed to start operation, the contact of the switch _C1 is closed and the motor FM of the fan 8 on the indoor side is driven, and at the same time, the above-mentioned The timer starts and cools down every 3 minutes. By setting the steps of the refrigerating capacity at the start of operation in advance, the motors MC ₁ and MC ₂ of the compressors 4 and 5 and the motors (not shown) of the fans F and F on the outdoor side are driven. Heating operation starts. Depending on whether 3 minutes have passed since the timer was started (issued), the temperature difference (Δt) between the detected temperature (t) and the set temperature (t ₀ ) will be determined until 3 minutes have passed. Determine whether or not the temperature difference (Δt) has shifted from region C to region D. (a) If the temperature difference (Δt) has shifted from region C to region D, then each of the compressors 4,
5, and if the current step is not the first or third step,
It outputs to the capacity control output section 35 in order to adjust the capacity level to the side where the refrigeration capacity decreases by one stage. Also, if the current step is the first or third step, the step is held.
(b) If the temperature difference (Δt) does not shift from region C to region D, the step is held at the current step in that case as well. On the other hand, [] When 3 minutes have elapsed since the timer was issued, the refrigeration capacity is increased or decreased according to the range of temperature difference (Δt) between the detected temperature (t) and the set temperature (t ₀ ) at the same time as the timer is issued. Alternatively, in order to control the blowing temperature at a constant level by holding the temperature, the capacity control output section 35 is configured to: (a) If the temperature difference (Δt) is in region A, the capacity step (capacity step) is changed to a capacity increase step that is one step higher; (b) If the temperature difference (Δt) is in region B, the capacity step outputs to maintain it; (c) If the temperature difference (Δt) is in region C or region D; If so, it is output so as to shift the capacity step to the next lower capacity reduction step. As described above, while adjusting the capacity steps (capacity steps) of the compressors 4 and 5 in 3-minute cycles, only when the detected temperature (t) reaches the judgment reference temperature (t ₁ ), the capacity step at that time is adjusted. The capacity step (capacity step) at any time unless it is the 1st or 3rd step.
Therefore, in cases other than the first and third steps, the temperature of the blowing air will rise too much during the 3-minute adjustment period and the high-pressure pressure switch HPS-1, The occurrence of a situation in which the HPS-2 works and the compressors 4 and 5 stop can be avoided as much as possible, and as a result, the frequency of stopping the compressors 4 and 5 can be reduced overall compared to the conventional case. In the above embodiment, the first and second determining means 24 and 28 are also programmed to control the controller 30.
However, as shown in FIG. 6, these first and second determining means 24 and 28 are constituted by a comparator 40 consisting of a multi-stage thermostat, and the detector 22 is connected to the input side of the comparator 40. , the first and second setting devices 23 and 27 may be connected to the controller 41, which is composed of an output side computer and incorporates the ability control command means 25 and the ability holding means 29. In this case, the comparator 40 and the controller 41 are
The comparator 40 is connected to the main output lines 42, 43, and 44, and the comparator 40 is connected to the range (A to D) of the temperature difference (Δt) between the detected temperature (t) and the set temperature (t ₀ ).
According to the combination of ON-OFF signals via the output lines 42, 43, 44, the seventh
As shown in the figure and Table 3, it is configured to output four types of signals. Based on these four types of signals, the controller 41 adjusts the capacity steps of the compressors 4 and 5 as in the previous embodiment.

[Table] (Effects of the Invention) As described above, the present invention, in addition to the first determination means 24, is capable of detecting a situation in which the discharge gas pressure increases extremely rapidly and reaches a high pressure in an unfavorable region based on the detected temperature (t). A second determination means 28 is provided for detecting whether the refrigerating capacity has changed, and the capacity control command means 25 adjusts the steps of the refrigerating capacity at predetermined intervals based on the output of the first determination means 24. When the temperature (t) reaches the judgment reference temperature (t ₁ ), the output of the second judgment means 28 immediately reduces the refrigerating capacity step, that is, the capacity level of the compressors 4 and 5 to the lower capacity side. Moreover, in the case where the compressors 4 and 5 stop when the capacity level of the compressors 4 and 5 is decreased by one step based on the output of the second determination means 28, the capacity retention means 29 By the output of Capacity control is performed and the frequency of the capacity control is reduced.However, in this periodic capacity control, even if the high pressure suddenly increases, the high pressure switches HPS-1 and HPS-2 will not operate. As a result, it is possible to reduce the frequency of stopping the compressors 4, 5 and improve their durability, as well as eliminate the need for the compressors 4, 5. This has the effect of making it possible to reduce the sudden drop in the blown air and to control the blown air temperature more stably.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a control system of an embodiment of the present invention, Fig. 2 is a refrigerant circuit diagram of the embodiment, Fig. 3 is a structural explanatory diagram of the embodiment, and Fig. 4 is a diagram of the same embodiment. Electrical circuit diagram, Fig. 5 is a flowchart showing capacity control during heating operation of the same embodiment, Fig. 6 is an electric circuit diagram showing another embodiment, and Fig. 7 is a comparator output of the same other embodiment. An explanatory diagram for explaining the state, FIG. 8 is an explanatory diagram of a conventional example. 4, 5...First and second compressors, 6,7...First and second heat exchangers, 8...Fan, 22...Detector (detection means), 23...First setting device ( (first setting means), 24...first determination means, 25...capacity control command means, 27...second setting device (second setting means), 28...second determination means, 29...capacity holding means .

Claims (1)

[Claims] 1 Equipped with heat exchangers 6 and 7 that are equipped with fans 8 and serve as condensers during heating, capacity control means that can control the capacity in stages, and high-pressure pressure switches HPS-1,
In an air conditioner having compressors 4 and 5 equipped with HPS-2, a detection means 22 for detecting the temperature of the blown air, a first setting means 23 for setting a set temperature of the blown air temperature, and the detection means 22 and the first
a first determination means 24 that compares the detected temperature and the set temperature based on each output from the setting means 23; and a temperature higher than the set temperature set by the first setting means 23 and the high pressure switch HPS-1. , a second setting means 27 for setting a judgment reference temperature lower than the blowing air temperature corresponding to the set pressure of HPS-2;
a second determining means 28 for determining whether the detected temperature has reached the determination reference temperature based on the outputs of the setting means 27 and the detecting means 22; The capacity level of the compressors 4, 5 is adjusted by one level, and the output of the second determining means 28 is simultaneously adjusted.
Capacity control command means 25 for adjusting the capacity level of No. 5 to the capacity decreasing side is provided, and this capacity control command means 25
The capacity retaining means 29 determines the capacity level, and when the compressors 4 and 5 stop when the capacity is decreased by one level, the adjustment output to the side where the capacity is decreased is maintained to maintain the current capacity level. An air conditioner that enables capacity adjustment.