JPH0617758B2 - Refrigerant heating type air conditioner - Google Patents

Description

Description: [Object of the invention] (Field of industrial application) The present invention relates to a refrigerant heating type air conditioner having a burner combustion amount control mechanism for heating a refrigerant heater.

(Prior Art) Generally, as a type of air conditioner, a refrigerant heater is connected in a heat pump type refrigeration cycle, and during cooling operation, the outdoor heat exchanger functions as a condenser and the indoor heat exchanger functions as an evaporator. In addition to forming a refrigeration cycle for cooling, the indoor heat exchanger functions as a condenser during heating operation, and the refrigerant liquid flowing out from the indoor heat exchanger is made to flow into the refrigerant heater via the pressure reducer. There is known a refrigerant heating type cooling and heating machine configured to form a heating refrigeration cycle for evaporating a refrigerant liquid in the refrigerant heater by heating the refrigerant heater by a heating means such as a gas burner.

By the way, conventionally, a compressor of variable capacity is mounted as a compressor of a refrigerant heating type air conditioner, and the combustion amount of the gas burner of the refrigerant heater is, for example, the opening of a gas proportional valve provided in the fuel gas supply pipe. A combustion amount control mechanism for controlling based on control is provided, and, for example, a compressor formed according to a difference between a set temperature and a detected room temperature detected by a room temperature sensor during heating operation by a control unit formed by a microcomputer and its peripheral circuits. Has been developed in which the capacity of the gas burner and the combustion amount of the gas burner are controlled as shown in FIG. In FIG. 4, a is a change state of the detected room temperature detected by the room temperature sensor, b is a change state of the capacity command signal from the control unit, c is a change state of the gas burner combustion amount, and d is an actual room heating. The change state of the ability, e is the change state of the actual room temperature. In this case, the gas proportional valve in the fuel gas supply pipe is variably operated in a plurality of stages of valve opening. The ability decreases operation as indicated by characteristic curve b in FIG. 4 in accordance with the degree of approach of the front and detected indoor temperature and the set temperature T ₀ of the detection chamber temperature detected by the temperature sensor reaches the set temperature T ₀ A signal is output and the compressor capacity and burner combustion amount are gradually reduced in response to the input of this capacity decrease operation signal to avoid repetition of the on / off of the room temperature sensor (capacity save operation. function).

However, since the heat capacity of the refrigerant heater is generally relatively large, the opening of the gas proportional valve in the fuel gas supply pipe is gradually reduced (throttled) in the above-mentioned conventional configuration with the input of the capacity reduction operation signal. However, there is a problem that the temperature of the refrigerant heater cannot be rapidly reduced even if the burner combustion amount is gradually reduced. Therefore, since the actual decrease in the indoor heating capacity was relatively gradual, the indoor temperature might rise to the operation stop command temperature T _s higher than the set temperature T _{0 of the} room temperature sensor. In this way, when the indoor temperature rises to the operation stop command temperature T _s , the operation of the compressor is stopped and the combustion of the burner is stopped at the times t ₁ and t ₃ . In this case, if the operation of the compressor is immediately restarted immediately after the operation of the compressor is stopped, the compressor main body will be adversely affected. Therefore, after the operation of the compressor is stopped, a predetermined time (for example, about 2 minutes and 20 seconds) can be restarted by a timer. ) The restart of the compressor is forcibly prevented. Therefore, during the operation of the compressor and the stop of the combustion of the burner (from the time t ₁ (t ₃ ) when the operation of the compressor is stopped to the time t ₂ (t ₄ ) when the compressor can be restarted, the room temperature is maintained. There is a risk that the temperature will decrease sharply, and for example, the temperature difference T ₁ between the set temperature T ₀ and the room temperature at the time t ₂ (t ₄ ) at which the compressor can be restarted will reach about 4 ° C., and comfort will be impaired. there were.

(Problems to be Solved by the Invention) In the conventional configuration, the opening of the gas proportional valve in the fuel gas supply pipe is gradually reduced (throttled) in response to the input of the capacity reduction operation signal to burner combustion. Even if the amount was gradually decreased, the temperature of the refrigerant heater could not be rapidly decreased, and the actual reduction of the indoor heating capacity was relatively gradual. Therefore, the room temperature rises to the operation stop command temperature T _s higher than the set temperature T _{0 of the} room temperature sensor, the operation of the compressor and the combustion of the burner are stopped, and the room temperature is stopped while the operation of the compressor and the combustion of the burner are stopped. Has a problem that the comfort is impaired because of a sudden drop.

The present invention has been made in view of the above circumstances, and prevents the operation of the compressor from being stopped when the detection room temperature reaches the set temperature in the room temperature rise region during the heating operation. It is an object of the present invention to provide a refrigerant heating type air conditioner that can prevent a sharp drop in room temperature immediately after the temperature reaches a set temperature and can improve comfort.

[Configuration of the Invention] (Means for Solving Problems) The present invention includes a burner combustion amount control mechanism that controls the combustion amount of the burner for heating the refrigerant heater during heating operation, and the detected room temperature is set to a predetermined value during heating operation. Refrigerant heating type cooling / heating machine equipped with a capacity saving operation means for stepwise reducing the combustion amount of the burner as the detected indoor temperature approaches the set temperature in the indoor temperature rising region before rising to the set temperature. In the indoor temperature rise region, the burner combustion amount reduction amount in each stage of gradually decreasing the combustion amount of the burner is initially set in a state where the reduction amount of the burner combustion amount is larger than the reference state at the initial stage. There is provided burner combustion state control means for holding the set time and returning the reduction amount of the burner combustion amount to the reference state after the set time has elapsed.

(Operation) The combustion amount of the burner in the indoor temperature rising region during the heating operation is gradually reduced. At the initial stage of switching the combustion amount of the burner at each stage, the reduction amount of the combustion amount of the burner is larger than the reference state and the predetermined amount is set. The set time is maintained, and after the set time elapses, the decrease amount of the burner combustion amount is returned to the reference state.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 shows a control circuit of a refrigerating cycle of the refrigerant heating type air conditioner shown in FIG. In FIG. 2, 1 is a variable capacity compressor, 2 is a four-way switching valve, 3 is an outdoor heat exchanger, 4 is a pressure reducing device such as an expansion valve, 5 is an indoor heat exchanger, and 6 is a refrigerant heater. These variable capacity compressor 1, four-way switching valve 2, outdoor heat exchanger 3, expansion valve 4 and indoor heat exchanger 5 are sequentially connected via a refrigerant pipe.

Further, the expansion valve 4 is provided between the outdoor heat exchanger 3 and the expansion valve 4.
A check valve 7 is provided to shut off the flow of the refrigerant flowing from the side toward the outdoor heat exchanger 3 side. Also, this check valve 7
Between the expansion valve 4 and the expansion valve 4, one end of a heating bypass passage 8 in which a refrigerant heater 6 is provided is connected. The other end of the bypass passage 8 is connected to the suction port side of the variable capacity compressor 1. In this case, a check valve 9 is provided between the suction port of the variable capacity compressor 1 and the four-way switching valve 2 to shut off the flow of the refrigerant flowing from the bypass passage 8 side toward the four-way switching valve 2 side.
Is installed. Further, in the bypass passage 8, a refrigerant recovery valve 10 is provided on the refrigerant inflow side of the refrigerant heater 6.

An outdoor fan 11 is provided near the outdoor heat exchanger 3, and an indoor fan 12 is provided near the indoor heat exchanger 5. Further, a gas burner 13 is arranged on the lower surface side of the refrigerant heater 6. A spark plug, a flame detector, and a combustion fan (not shown) are provided near the gas burner 13. The gas burner 13 is connected to a fuel supply source via a gas pipe 14, and the gas pipe 14 has a proportional control valve (combustion amount control mechanism).
15 and an electromagnetic on-off valve 16 are provided. In this case, the proportional control valve 15 can change the opening degree from the fully open state to the minimum opening state in, for example, five stages, and the combustion amount of the gas burner 13 can be set in five stages according to the opening degree of the proportional control valve 15. It is adjustable.

On the other hand, in FIG. 1, 21 is a commercial AC power supply, and its power supply 2
The inverter circuit 22 is connected to 1. The inverter circuit 22 rectifies a power supply voltage, converts the power supply voltage into an alternating current having a predetermined frequency and voltage, and supplies the alternating current to the drive motor 1M of the compressor 1 as drive power.
Further, reference numeral 23 is a control unit for controlling the entire refrigerant heating type air conditioner, which is composed of a microcomputer and its peripheral circuits, and is externally provided with a driving operation unit 24 and a room temperature sensor 2.
5, an inverter drive circuit 26, a four-way switching valve 2, a refrigerant recovery valve 10, an outdoor fan 11, an indoor fan 12, an electromagnetic opening / closing valve 16, an ignition plug, a flame detector, and a combustion fan are connected to each other, and a combustion amount control is performed. The proportional control valve 15 is connected via the device 27. The control unit 23 controls the capacity of the compressor 1 and the combustion amount of the gas burner 13 according to the difference between the set temperature set by the operation operation unit 24 and the detected indoor temperature detected by the room temperature sensor 25 during the heating operation. At the same time, a capacity decrease operation signal is output according to the degree of approach between the detected room temperature and the set temperature before the detected room temperature reaches the set temperature. With the input of the capacity decrease operation signal, the capacity of the compressor 1 and the gas burner 13 In addition to the built-in capacity saving operation means for gradually decreasing the combustion amount of the gas burner 13, when the capacity decrease operation signal is input, the combustion amount of the gas burner 13 is gradually decreased at the initial stage of switching the combustion amount of each gas burner 13. The combustion amount of the gas burner 13 is kept larger than the reference state, and the gas burner 1 is maintained for a predetermined set time, and after the set time elapses, the gas burner 1 Control means is provided in the burner combustion conditions for returning to the reference state amount of decrease in the combustion amount.

Next, the operation of the above configuration will be described. First, the operation operation unit 24 selects the cooling operation or the heating operation, sets a desired room temperature, and performs an operation start operation. In this case, during the cooling operation, the control unit 23 drives the inverter circuit 22 via the inverter drive circuit 26, the compressor 1 is started, and the four-way valve 2 is switched to the state shown by the dotted line in FIG. It Further, the refrigerant recovery valve 10, the proportional control valve 15, and the electromagnetic opening / closing valve 16 are held in a closed state. Therefore, in this case, the refrigerant discharged from the variable capacity compressor 1 flows through the four-way switching valve 2, the outdoor heat exchanger 3, the expansion valve 4, and the indoor heat exchanger 5 in this order as indicated by the dotted arrow in FIG. A refrigeration cycle for cooling is formed, and a cooling operation is started in which the outdoor heat exchanger 3 functions as a condenser and the indoor heat exchanger 5 functions as an evaporator.

On the other hand, during the heating operation, the control unit 23 drives the inverter circuit 22 via the inverter drive circuit 26 to start the compressor 1 and switch the four-way valve 2 to the state shown by the solid line in FIG. . In this case, the refrigerant recovery valve 10 is kept in a closed state for a certain period of time after the start of operation,
A refrigerant recovery operation for recovering the refrigerant remaining in the outdoor heat exchanger 3 is performed.

Further, after a certain period of time, when the refrigerant recovery operation is completed, the refrigerant recovery valve 10 is opened, and the proportional control valve 15 and the electromagnetic opening / closing valve 16 are opened respectively, and the gas burner 13 is opened.
Is ignited. Therefore, as the refrigerant recovery valve 10 is opened, the refrigerant discharged from the variable capacity compressor 1 is transferred to the four-way switching valve 2, the indoor heat exchanger 5, as shown by the solid line arrow in FIG.
A refrigeration cycle for heating is formed in which the expansion valve 4 and the refrigerant heater 6 are flowed in this order. In this case, when the refrigerant liquid flowing out from the indoor heat exchanger 5 due to the ignition of the gas burner 13 is introduced into the refrigerant heater 6 via the expansion valve 4, the refrigerant liquid flowing in the refrigerant heater 6 becomes the gas burner 13 Since it is heated and evaporated by the indoor heat exchanger 5,
The heating operation is started to make each of them function as an evaporator.

Further, during heating operation, the difference between the temperature detected by the room temperature sensor 25 and the indoor set temperature by the control unit 23 (heating load).
Is calculated and the output frequency of the inverter circuit 22 and the opening degree of the proportional control valve 15 are controlled according to this temperature difference, and the capacity of the compressor 1 and the combustion amount of the gas burner 13 are shown by the solid lines in FIG. Controlled by. That is, outputs a capacity decrease operation signal in accordance with the degree of approach between the detected indoor temperature and the set temperature T ₀ before the detection chamber temperature reaches the set temperature T ₀ from temperature sensor 25, the input of this ability decreases driving signal Along with the capacity of the compressor 1 and the gas burner 13
A capacity saving operation is performed to gradually reduce the combustion amount of. Therefore, when the temperature difference between the detected room temperature from the room temperature sensor 25 and the set temperature T ₀ is large as immediately after the start of operation, the control unit 23 causes the capacity of the compressor 1 and the combustion amount of the gas burner 13 to be in the maximum state. As shown in a characteristic curve B in FIG. 3, as the temperature difference becomes smaller, a capacity decreasing operation signal for decreasing the capacity stepwise from the maximum capacity state to the minimum capacity state in five steps is output. . Then, the output frequency of the inverter circuit 22 is reduced stepwise according to the capacity reduction operation signal. At the time of inputting this capacity decreasing operation signal, the opening degree of the proportional control valve 15 is changed from the fully open state of the fifth stage, for example, by the burner combustion special state control function of the control unit 23 as shown by the characteristic curve C in FIG. By narrowing the opening to the third-stage opening state, which is smaller than the fourth-stage opening state, the capacity reduction amount is larger than the normal capacity reduction state (fourth-stage opening state). state for a predetermined set to the time t ₀ holds the combustion amount of gas burner 13 with (3-stage opening state of) four stages from opening state of the third stage of the opening of the proportional control valve 15 after the set time t ₀ has elapsed The degree of combustion of the gas burner 13 is returned to the normal capacity reduction state by returning to the eye opening state. Further, the proportional control valve 15
When the opening degree of is reduced from the opening state of the fourth stage to the opening state of the third stage, the opening degree is once changed to the opening state of the second stage which is smaller than the opening state of the third stage. By narrowing down, the combustion amount of the gas burner 13 is maintained for a predetermined set time t _{0 in a} special state (second stage opening state) in which the amount of capacity reduction is larger than the normal capacity reducing state (third stage opening state). Then, after the set time t _{0 has} elapsed, the opening degree of the proportional control valve 15 is returned from the opening degree state of the second stage to the opening degree state of the third stage, and the combustion amount of the gas burner 13 is returned to the normal capacity reduction state. The same applies to the case where the opening degree of the proportional control valve 15 is reduced from the opening state of the third stage to the opening state of the second stage.

Therefore, in the configuration described above, during the heating operation, the combustion amount of the gas burner 13 is reduced at the initial stage of switching the combustion amount of the gas burner 13 in each stage in which the combustion amount of the gas burner 13 is gradually reduced in the indoor temperature rising region. A burner combustion state control means is provided for holding a predetermined set time T _{0 in} a state where the amount is larger than the reference state, and for returning the decrease amount of the combustion amount of the gas burner 13 to the reference state after the set time T ₀ has elapsed. , The temperature of the refrigerant heater 6 is accelerated, and the actual indoor heating capacity is rapidly reduced as compared with the conventional one (shown by a virtual characteristic curve d in the figure) as shown by a characteristic curve D in FIG. Can be made. Therefore, it is possible to prevent the indoor temperature from rising to the operation stop command temperature T _s higher than the set temperature T ₀ of the room temperature sensor 25 as in the conventional case, and thus the operation of the compressor 1 and the gas burner 13 during the heating operation. It is possible to prevent the combustion from being stopped and the room temperature to drop sharply. Therefore, as shown by the characteristic curve E in FIG. 3, for example, the temperature difference T ₂ between the set temperature T ₀ and the minimum temperature during normal heating operation can be reduced to about 1.5 ° C. It is possible to improve comfort as compared with the characteristic curve e shown by a virtual line in the figure).

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the case where the combustion amount of the gas burner 13 is changed in five stages is shown, but it may be changed in a plurality of stages other than that. Further, although the case where the gas burner 13 in which the fuel is gas is used has been described in the above embodiment, the burner in which the oil is fuel may be used. Furthermore, it goes without saying that various modifications can be made without departing from the scope of the present invention.

EFFECTS OF THE INVENTION According to the present invention, in the indoor temperature rising region during the heating operation, the reduction amount of the combustion amount of the burner at the initial stage of switching the combustion amount of the burner in each stage for gradually reducing the combustion amount of the burner is the standard. Since the burner combustion state control means is provided for holding the burner for a predetermined set time longer than the state and for returning the decrease amount of the burner combustion amount to the reference state after the set time elapses, the detected indoor temperature in the indoor temperature rising region The temperature inside the room after reaching the set temperature is prevented from rising to a shutdown command temperature higher than the set temperature, and the detected room temperature reaches the set temperature in the room temperature rise area during heating operation. At this time, it is possible to prevent the operation of the compressor from being stopped. Therefore, it is possible to prevent a sudden drop in room temperature due to the operation stop of the compressor immediately after the detected room temperature reaches the set temperature, and it is possible to improve comfort.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention.
FIG. 1 is a schematic configuration diagram showing a control circuit of a refrigerant heating type air conditioner, FIG. 2 is a schematic configuration diagram showing a refrigeration cycle of the refrigerant heating type air conditioner, and FIG. 3 is a temperature detected by a room temperature sensor during heating operation, FIG. 4 is a characteristic diagram showing a capacity command signal, a combustion amount, an actual heating capacity and a change state of room temperature, and FIG. 4 is a temperature detected by a room temperature sensor during heating operation in a conventional refrigerant heating and cooling machine, a capacity command signal, a combustion amount, It is a characteristic view which shows the actual heating capacity and the change state of room temperature. 6 ... Refrigerant heater, 13 ... Gas burner, 15 ... Proportional control valve (combustion amount control mechanism), 23 ... Control section.

Claims (1)

[Claims] 1. A burner combustion amount control mechanism for controlling a combustion amount of a burner for heating a refrigerant heater during a heating operation, and in a heating temperature operation in an indoor temperature rising region before a detected indoor temperature rises to a predetermined set temperature. In a refrigerant heating type air conditioner provided with a capacity saving operation means for gradually reducing the combustion amount of the burner as the detected indoor temperature approaches the set temperature, in the indoor temperature rising region, the burner combustion is performed. In the initial stage of switching the combustion amount of the burner in each step of gradually reducing the amount, the amount of decrease in the combustion amount of the burner is held for a predetermined set time in a state larger than the reference state, and after the set time has elapsed, the burner is held. A refrigerant heating type cooling and heating machine, characterized by further comprising burner combustion state control means for returning the reduction amount of the combustion amount of the above to the reference state.