JPS62293055A - 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 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to an air conditioner using a heat pump type refrigeration cycle.

2. Description of the Related Art An example of an air conditioner using a conventional heat pump type refrigeration cycle will be described with reference to the drawings.

FIG. 5 shows a refrigeration cycle diagram in a conventional air conditioner.

In Fig. 5, 1 is a compressor, 2 is a four-way valve, 3 is an indoor heat exchanger, 4 is a pressure reduction mechanism, 5 is an outdoor heat exchanger, and 6 is an accumulator, which are sequentially connected in a ring with refrigerant piping 7 to form a refrigeration cycle. are doing. 8 is an indoor heat exchanger fan, and 9 is an outdoor heat exchanger fan.

The operation of the air conditioner configured with the above-described refrigeration cycle will be described below. Now, taking heating operation as an example, as shown by the solid arrow in FIG. Inflow. During heating, the indoor heat exchanger 3 acts as a condenser,
The inflowing refrigerant gas is condensed and liquefied by releasing heat to the surrounding indoor air, adiabatically expanded by the pressure reducing mechanism 4 to become a low temperature, low pressure gas/liquid two-phase state, and flows into the outdoor heat exchanger 5. At this time, since the outdoor heat exchanger 5 is an evaporator, the two-phase refrigerant absorbs heat from the surrounding outdoor air, evaporates, and becomes a low-temperature, low-pressure refrigerant gas, which flows into the accumulator 6 and returns to the compressor 1. is inhaled. In this way, the indoor heat exchanger 3, which is a condenser, can heat the room by exchanging heat between the high-temperature, high-pressure refrigerant gas and the indoor air. On the other hand, during cooling operation, cooling is performed by switching the four-way valve 2 to reverse circulation as shown by the broken line arrow in FIG.

In many of these air conditioners, the four-way valve 2 is energized during heating, so when the operation stop switch is turned off at the end of heating, the operation of the compressor 1 etc. is stopped and at the same time the four-way valve 2 is also turned on. It becomes de-energized and switches. Therefore, the high-temperature, high-pressure liquid refrigerant that was present in the indoor heat exchanger 3 flows back into the accumulator 6, which was at a low pressure, and the pressure is instantly balanced. As a result, most of the refrigerant sealed in the refrigeration cycle remains in the accumulator 6, and if left for a long time until the next heating starts, the refrigerant passes through the refrigerant pipe 7 and enters the lubricating oil in the compressor 1. A so-called stagnation phenomenon, in which the metal melts into the metal, also occurs. When heating operation is restarted under these conditions, most of the refrigerant is present in the compressor 1 and accumulator 6, so the amount of refrigerant circulating in the refrigeration cycle is small (
Therefore, the amount of heat exchanged with the surrounding air in the indoor heat exchanger 3 and the outdoor heat exchanger 5 is also small, resulting in poor start-up. In addition, due to the intense stirring action after the compressor 1 is started, the compressor 1
A so-called foaming phenomenon occurs in which the refrigerant dissolved in the lubricating oil inside foams, and the lubricating oil protrudes out of the compressor 1.

Furthermore, the liquid refrigerant that has accumulated in the accumulator 6 is sucked into the compressor 1, causing a liquid compression phenomenon.

Problems to be Solved by the Invention As mentioned above, in air conditioners using conventional heat pump refrigeration cycles, the amount of refrigerant circulated at the initial stage of startup is small, so heat is absorbed from the outdoor ambient air and heat is radiated to the indoor ambient air. is small, and the increase in compressor work is slow.As a result, in the case of a high-pressure type compressor, the amount of heat generated is small and the temperature of the compressor does not rise easily. In this way, it takes a considerable amount of time for the refrigeration cycle to reach a steady state, and during this time, sufficient heating capacity is not obtained, resulting in problems such as the hot air not blowing out easily or the temperature of the entire room rising slowly. had. Furthermore, there have been problems in that forming phenomena and liquid compression phenomena occur during the initial stage of startup, which affects reliability.

The present invention has been made in view of the above-mentioned problems, and provides a heat pump type air conditioner that quickly blows out warm air when starting heating and blowing cold air when starting cooling, and which has a quick start-up (fall) and is reliable. It also aims to improve sexual performance.

Means for Solving the Problems In order to solve the above problems, the heat pump air conditioner of the present invention includes a compressor whose rotation speed is controlled, a four-way valve, an indoor heat exchanger, a pressure reduction mechanism, and an outdoor heat exchanger. are sequentially connected in a collapsed shape with refrigerant piping, and an opening/closing mechanism is provided in the flow path between the outlet side of the indoor heat exchanger and the inlet side of the outdoor heat exchanger, and the discharge side of the compressor and the four sides A check valve is installed in the flow path between the valves to configure a refrigeration cycle, and an indoor heat exchanger fan, an outdoor heat exchanger fan, and a physical quantity detection device are also installed, and the opening/closing mechanism is activated when an operation stop signal is generated. performs a closing operation, the compressor is operated at an initial rotation speed N1, and when the detection value of the physical quantity detection device reaches a certain value, the rotation speed is sequentially decreased and the compressor is operated for a certain period of time, and then turned off, and the four-way valve is turned off. is equipped with a control device that stops the operation while maintaining the cycle until the next operation start signal is generated.

Effect: With the above configuration, the opening/closing mechanism is closed at the end of the heating (cooling) operation, and at the same time, the compressor reaches the initial rotation speed N1.
The motor is operated at
In addition, by stopping the four-way valve while maintaining heating (cooling) operation, most of the enclosed refrigerant is stored in the indoor heat exchanger by the opening/closing mechanism and check valve during heating, and the next heating operation is started. be able to. As a result, a large amount of refrigerant circulates from the indoor heat exchanger to the outdoor heat exchanger when heating starts, leading to an increase in the amount of heat absorbed in the outdoor heat exchanger. In addition, since the refrigerant shortage phenomenon in the outdoor heat exchanger is alleviated, the drop in low pressure is small, and the compressor sucks refrigerant gas with a high density, resulting in a large compressor discharge amount and a large amount of work. Become. In this way, due to the increase in the amount of heat absorbed in the outdoor heat exchanger and the increase in the amount of work in the compressor, the amount of heat released in the indoor heat exchanger increases, leading to an increase in heating capacity, resulting in an air conditioner that starts up quickly. On the other hand, since most of the refrigerant is present in the indoor heat exchanger before startup, the phenomenon of stagnation in the lubricating oil in the compressor is alleviated, and since there is not much refrigerant in the accumulator, Forming phenomena and liquid compression phenomena are alleviated compared to conventional methods, and reliability is also improved.

EXAMPLE Hereinafter, a heat pump type air conditioner according to an example of the present invention will be described with reference to the drawings.

In Fig. 1, 1 is a compressor, 11 is a check valve, 2 is a four-way valve, 3 is an indoor heat exchanger, 1o is an electromagnetic on-off valve which is an example of an on-off mechanism, 4 is a pressure reduction mechanism, and 5 is an outdoor heat exchanger. The accumulators 6 and 6 are connected in a ring through refrigerant pipes 7 to form a refrigeration cycle.

8 is a fan for the indoor heat exchanger, 9 is a fan for the outdoor heat exchanger, and 13 and 14 are piping sensors for the indoor heat exchanger and the outdoor heat exchanger, respectively.

FIG. 2 shows a control circuit in the first embodiment of the present invention. In FIG. 2, 20 is a power supply, 21 is an operation switch,
22 and 27 are the relay and coil of the four-way valve February, respectively.
3 and 28 are relays and coils for the electromagnetic on-off valve 10, respectively, 33 is a rotation speed converter for the compressor 1, 31 is a drive motor for the compressor 1, and 32 is a control for opening and closing of various relays and a rotation speed converter 33. It is a control device that performs control, and is connected to a temperature detection device 1S, which is one of the physical quantity detection devices. Furthermore, the temperature detection device 15 includes an indoor heat exchanger pipe sensor 1 for detecting the refrigerant pipe temperature, which is one of the physical quantities.
3 and an outdoor heat exchanger piping sensor 14 are connected.

The operation of the heat pump type air conditioner configured as described above will be explained below using the time chart shown in FIG. 3, taking heating time as an example.

During heating operation, the refrigerant gas at high temperature cavity pressure that has been adiabatically compressed in the compressor 1 passes through the check valve 11 and the four-way valve 2, flows into the indoor heat exchanger 3 that serves as a condenser during heating, and is absorbed by the surrounding indoor air. The heat of condensation is released through heat exchange with the liquid, resulting in condensation and liquefaction.

After passing through the electromagnetic on-off valve 10 and undergoing adiabatic expansion by the pressure reducing mechanism 4, the gas enters a gas-liquid two-phase state at low temperature and low pressure, and flows into the outdoor heat exchanger 5, which serves as an evaporator during heating. There, the heat of evaporation is absorbed by heat exchange with the surrounding outdoor air, and the air is evaporated, passed through the accumulator 6, and sucked into the compressor 1 again. In this way, the heat of condensation of the refrigerant is blown out from the indoor heat exchanger 3 as warm air, generating heating capacity and raising the temperature of the indoor air.

Now, when the operation stop button is pressed to end the heating operation (at time τ1 in FIG. 3), an operation stop signal is generated, and the control unit @32 detects this and performs the following operation. At the same time as the operation stop signal is generated, the control device 32 activates the relay 2.
3 is used as the open contact point, the coil 28 for the electromagnetic on-off valve 10 is de-energized, and the flow path, which was previously open, is closed.

Further, the control device 32 sends a signal indicating the initial compressor rotation speed N1 to the rotation speed converter 33, and operates the compressor 1 at the rotation speed. The compressor 1 continues to operate, but during this time the pipe temperature of the indoor heat exchanger is constantly detected by the pipe sensor 13 and temperature detection device 16 installed in the indoor heat exchanger a, which serves as a condenser during heating. It has become. If the pipe temperature reaches a preset or stored constant value (θ1 in Figure 3) before a certain period of time (T) has elapsed since the operation stop signal was generated (at time τ1), the temperature at τ2 in Figure 3 The control device 32 recognizes this and sends the rotation speed converter 33 to the compressor rotation speed N2 (N2 (N1)).
The compressor 1 is operated at the rotation speed N2. Thereafter, the same operation is repeated until the pipe temperature reaches a certain value, and the rotational speed of the compressor 1 is gradually lowered. In this way, a certain period of time (
℃ has elapsed (at the time of τ3), the control device 32 sends a stop signal to the rotation speed converter 33 to turn off the compressor 1.

At the same time, the operation switch 21 also becomes an open contact and all heating operations are stopped. However, at this time, only the relay 22 for the four-way valve 2 is controlled by the control device 32 to keep the contact closed, and as a result, the four-way valve 2 remains energized and continues to maintain the heating cycle. . Thereafter, when the operation stop button is pressed to restart the heating operation after several hours have passed (at time τ4 in FIG. 3), the operation switch 21 becomes a closed contact, and at the same time, the control device 32 sends a rotation speed converter. A signal representing the rotation speed N is sent to a3, turning on the compressor 1, and the relay 23 for the electromagnetic on-off valve 10 becomes a closing contact, energizing the electromagnetic on-off valve 10, opening the flow path, and starting heating operation. It will be restarted.

Here, the piping temperature of the indoor heat exchanger 3 is detected from when the operation stop signal is generated (at time τ1) until a certain period of time has elapsed (at time τ3), and when it reaches a certain value (θ1), compression is performed sequentially. The reason why the rotational speed of the machine 1 is decreased is to prevent an abnormal rise in high pressure. In other words, if the flow path is closed by the electromagnetic on-off valve 10 at the same time as the operation stop signal is generated,
The high pressure increases, but since there is a correlation between the high pressure and the pipe temperature of the indoor heat exchanger 3, which serves as a condenser during heating, it is possible to prevent an abnormal rise in the high pressure by detecting the pipe temperature. can.

Although the explanation has been given above regarding heating, the same applies to cooling. However, during cooling, the four-way valve 2 switches and the condenser becomes the outdoor heat exchanger 5 and the evaporator becomes the indoor heat exchanger 3, so the pipe temperature is detected by the pipe sensor 1 for the outdoor heat exchanger 5.
4 will be used.

As described above, according to this embodiment, the operation of the compressor 1 is stopped after a predetermined period of time has elapsed after the flow path is closed by the electromagnetic on-off valve 10 at the end of heating.

In addition, since the four-way valve 2 is still maintaining the heating cycle at this time, most of the refrigerant is contained in the electromagnetic on-off valve 10 and the check valve 1.
1 and is retained in an indoor heat exchanger 3 which is a condenser. As a result, when the heating operation is resumed, the amount of refrigerant circulating from the indoor heat exchanger 3 to the outdoor heat exchanger 5 is large, and therefore the amount of heat absorbed by the outdoor heat exchanger increases. At the same time, the shortage of refrigerant in the outdoor heat exchanger 5 is alleviated, so the drop in low pressure is small, and the amount of work in the compressor 1 is also increased. In this way, since the amount of heat absorbed and the amount of work increase, the amount of heat released also increases, making it possible to quickly ramp up the heating capacity.

Further, a second embodiment of the present invention is shown in FIG.

A fully closable electric expansion valve 12 is provided in place of the opening/closing mechanism and the pressure reducing mechanism. As described above, as long as the flow path can be completely closed and the device also functions as a pressure reducing mechanism, the effects of the present invention can be fully brought out and there is no problem.

In addition, although the physical quantity detection device in the first embodiment of the present invention is a temperature detection device that detects the pipe temperature of the indoor heat exchanger and the outdoor heat exchanger, physical quantities other than this embodiment include the temperature of the blown air, the high pressure The side pressure and total current may be measured and the detection device used for these may be used as a physical quantity detection device, and the effect will not change at all.

Effects of the Invention As described above, the heat pump type air conditioner of the present invention stores refrigerant in the indoor (outdoor) heat exchanger, which is a condenser, when heating (cooling) ends, until the next heating (cooling) starts. If the operation is restarted while maintaining this state, the amount of refrigerant circulating from the condenser to the outdoor (indoor) heat exchanger that is the evaporator increases, and the amount of heat absorbed in the evaporator increases. In addition, the amount of work in the compressor increases accordingly, so the amount of heat dissipated in the condenser increases, and as a result, the refrigeration cycle reaches steady state early, so hot air (cold air) is blown out quickly, and the rise ( falling)
This makes it possible to provide a quick air conditioner. Also,
Most of the sealed refrigerant is present in the indoor (outdoor) heat exchanger through the opening/closing mechanism and check valve, so the amount of stagnation in the oil in the compressor is small, which alleviates the forming phenomenon after startup, and also reduces the amount of oil trapped in the accumulator. Since the refrigerant does not stagnate much, the liquid compression phenomenon is also alleviated, and it exhibits excellent effects in terms of reliability.

[Brief explanation of drawings]

Fig. 1 is a refrigeration cycle diagram of a heat pump air conditioner according to the first embodiment of the present invention, Fig. 2 is a control circuit diagram of Fig. 1, and Fig. 3 is a time chart diagram of the first embodiment. FIG. 4 is a refrigeration cycle diagram in a second embodiment of the present invention, and FIG. 5 is a refrigeration cycle diagram of a conventional heat pump type air conditioner. 1... Compressor, 2... Four-way valve, 3...
... Indoor heat exchanger, 4... Pressure reduction mechanism, 5.
...Outdoor heat exchanger, 7... Refrigerant piping, 8...
...Indoor heat exchanger fan, 9...Outdoor heat exchanger fan, 10...Opening/closing mechanism, 11...
Check valve, 15...Physical quantity detection device, 32...
·Control device. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 5

Claims (2)

[Claims] (1) A compressor whose rotational speed is controlled, a four-way valve, an indoor heat exchanger, a pressure reduction mechanism, and an outdoor heat exchanger are sequentially connected in a ring with refrigerant piping, and the outlet side of the indoor heat exchanger and the outdoor heat exchanger are connected in order. A refrigeration cycle is constructed by providing an opening/closing mechanism in the flow path between the inlet side of the compressor and a check valve in the flow path between the discharge side of the compressor and the four-way valve. An exchanger fan, an outdoor heat exchanger fan, and a physical quantity detection device are provided, and when an operation stop signal is generated, the opening/closing mechanism performs a closing operation, the compressor is operated at an initial rotation speed N_1, and the detection value of the physical quantity detection device is When the rotation speed reaches a certain value, the four-way valve is turned off after operating for a certain period of time while gradually decreasing the rotation speed, and the four-way valve stops operation while maintaining the current cycle until the next operation start signal is generated. Heat pump type air conditioner installed. (2) The physical quantity detection device is a device for detecting physical quantities such as pipe temperature, outlet air temperature, high pressure side pressure, or total current of the indoor heat exchanger and outdoor heat exchanger, as set forth in claim 1. heat pump type air conditioner.