JPH0212346B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention heats the refrigerant circulating in the refrigeration cycle during the evaporation process during heating operation, and also heats the refrigerant circulating in the refrigeration cycle without circulating it through the refrigeration cycle. This relates to a heat pump type air conditioner that is released to bypass the compressor from its discharge side to its suction side.In particular, it controls the balance between the amount of heating of refrigerant during the evaporation process and the amount of refrigerant released to bypass, and improves the refrigeration cycle. In addition to maintaining stable operating conditions,
The present invention relates to an air conditioner that can suppress power consumption and improve economic efficiency as much as possible.

[Technical background of the invention and its problems]

A conventional refrigeration cycle was constructed as shown in FIG.

The refrigerant in the refrigeration cycle circulates in the circuit 4 due to the pressure difference between the discharge side (high pressure side) 2 and the suction side (low pressure side) 3 of the compressor 1, while changing its phase due to heat exchange.

During heating operation, the refrigerant gas compressed by the compressor 1 passes through the four-way valve 5 (forming the flow path indicated by the solid line in the figure) and is delivered to the air-conditioned room (not shown).
The heat is guided to the indoor heat exchanger 6 provided inside, where it is condensed to release latent heat, thereby heating the air-conditioned room (not shown).

The refrigerant condensed in the indoor heat exchanger 6 is further transferred to the low pressure side 3.
The water flows through the circuit 4 and reaches the first branch point 7, but because one of the flow paths is provided with a first check valve 8, it cannot flow any further; It flows into the other flow path and is guided to the heat exchanger 9 for heating the refrigerant. Here, the refrigerant is heated by the combustor 10, evaporates, and changes its phase to a gaseous state, thereby storing the heat as latent heat.

The gaseous refrigerant further flows through the circuit 4 toward the low-pressure side 3, passes through the two-way valve 11 opened midway, and reaches the second branch point 12; Since the check valve 13 of No. 2 is provided, the flow cannot flow any further, and furthermore, the low pressure side No. 3
and returns to the compressor 1, forming a heating circuit 14 (indicated by a thick solid line in the figure) of the refrigeration cycle.

Additionally, in this air conditioner (not shown), part of the refrigerant is released from the discharge side 2 of the compressor 1 during the compression process without circulating through the heating circuit 14 of the refrigeration cycle, and is bypassed to the suction side 3. A release circuit 15 is formed to allow the release circuit to be released. A release valve 16 is interposed in the middle of this release circuit 15, and the release circuit 15 is opened and closed by opening and closing the release valve 16. During heating operation, the circuit 15 is opened and closed.
is opened and closed during cooling operation.

By the way, the heating capacity of this air conditioner (not shown) is determined by the amount of work due to compression by the compressor 1 and the amount of heating of the refrigerant in the refrigerant heating heat exchanger 9, that is, the combustor 10.
The heating capacity is adjusted by adjusting the combustion amount of the combustor 10 in response to fluctuations in the heat load (heating load) in the air-conditioned room (not shown). It is done by doing. Specifically, the amount of fuel supplied to the combustor 10 is adjusted.

On the other hand, the amount of refrigerant flowing through the release circuit 15 is determined by the flow path resistance of the release circuit 15 and the pressure difference between the discharge side and the suction side of the compressor 1. It is set according to the amount of combustion.

By the way, generally when the heating load (heat load) decreases, the pressure in the heating circuit 14 increases, and the compressor 1
The suction side pressure also increases, and the amount of refrigerant circulated within the circuit 14 tends to increase. At this time, even if the combustion amount of the combustor 10 was reduced in accordance with the heat load, the amount of refrigerant circulating tended to increase, causing the problem that the refrigeration cycle became unstable and took a considerable amount of time to stabilize.

Further, the amount of refrigerant sealed in the circuit 4 of the refrigeration cycle is determined depending on the cooling capacity, heating capacity, etc. of the air conditioner (not shown). By the way, as mentioned above, the combustion amount of the combustor 10 is adjusted according to the increase or decrease of the heat load, but if the sealed refrigerant leaks for some reason,
The heating capacity of the air conditioner (not shown) decreases, and if normal heating operation is performed without noticing this, the heat load will gradually increase by the amount of the lack of capacity, and the amount of combustion will increase depending on the amount of refrigerant circulated. Even though it was not obtained, the amount increased, which hindered the normal operation of the refrigeration cycle, and caused problems such as damage to equipment due to overheating.

In addition, for cooling operation, switch the four-way valve 5,
If the flow path is formed as shown by the broken line in the figure, normal cooling operation using the refrigeration cycle will be performed.
In the figure, 17 is an outdoor heat exchanger forming a condenser of the cooling circuit, and 18 is a throttle device using a capillary tube or an expansion valve.

[Purpose of the invention]

The present invention provides an air conditioner that can maintain an appropriate amount of circulating refrigerant in the heating circuit in response to a reduction in the heat load of the air-conditioned room when performing heating operation with an air conditioner equipped with a refrigerant heating heat exchanger and a release circuit. The purpose is to provide a harmonizing machine.

[Summary of the Invention] In order to achieve the above object, the present invention forms a refrigeration cycle by sequentially connecting a compressor, an outdoor heat exchanger, a pressure reduction device, and an indoor heat exchanger, and provides a refrigeration cycle during heating operation. The condensed refrigerant from the indoor heat exchanger flows into the refrigerant heating heat exchanger, where the condensed refrigerant is heated and evaporated and returned to the compressor.A heating circuit is connected, and a portion of the refrigerant discharged from the compression side is bypassed to the suction side. In an air conditioner connected to a release circuit and further provided with a combustor for heating a refrigerant to the refrigerant heating heat exchanger, there is provided a means for detecting a heat load in an air-conditioned room during heating operation, and a variation in the heat load. and a release control means that controls the amount of refrigerant released from the release circuit in accordance with the amount of fuel supplied by the fuel supply means. By increasing the amount of refrigerant released by the release control means in response to a decrease in heat load, the amount of refrigerant circulated within the heating circuit is reduced, thereby allowing stable operation even if the amount of combustion in the combustor is reduced.

[Embodiments of the invention]

Hereinafter, a preferred embodiment of the air conditioner according to the present invention will be described with reference to the accompanying drawings.

In the air conditioner according to the present invention, the configuration of the air conditioning circuit itself forming the refrigeration cycle is the same as that of the conventional example.

As shown in FIG. 2, a combustion supply system 19 for supplying combustion of gas or the like is connected to the combustor 10, and a fuel supply control means 20 for controlling the amount of fuel supplied is connected to the supply system. On the other hand, in the middle of the release circuit 15, there is a release control means 21 such as an electric valve that communicates with the control of the fuel supply control means 20 and controls the amount of refrigerant released from the compressor 1 stepwise or continuously.
is connected.

First, although the details are not shown, the fuel supply means 20 is controlled by a control device to supply combustion to the combustor 10 according to fluctuations in the heat load (heating load) in the air-conditioned room (not shown). The amount of supply is now controlled. In other words, for example, a room temperature sensor is installed on the side of the air-conditioned room, and the control device determines the heat load based on the difference between the room temperature detected by this room temperature sensor and the set temperature, and calculates the heat load until the room temperature reaches the set temperature. The release control means controls the amount of fuel supplied by the fuel supply control means 20 to decrease in accordance with the decrease in the amount of fuel supplied, and at the same time reduces the amount of refrigerant circulated within the heating circuit 14 in accordance with the decrease in the amount of fuel supplied. The amount of refrigerant released by 21 is controlled to increase stepwise or continuously.

Further, in the heating circuit 14, a pressure detection device 22 is provided on the suction side 3 of the compressor 1 to detect when the pressure in the circuit 14 becomes below a certain value during heating operation and to issue a signal. 23 is a fuel cutoff device for receiving this signal and preferentially stopping the fuel supply of the fuel supply control means 20.

Next, the operation of the present invention will be described.

During heating operation, when the heat load within the air-conditioned room (not shown) decreases, the pressure within the heating circuit 14 increases and the amount of refrigerant circulated within the circuit 14 tends to increase. At this time, in order to reduce and adjust the heating capacity,
The fuel supply control means 20 operates to reduce the amount of fuel supplied to the combustor 10. This control means 20
A signal indicating that the fuel supply amount has decreased is transmitted to the release control means 21, and upon receiving this signal, the release control means 21 operates to increase the flow rate of the refrigerant circulating within the release circuit 15. By the amount of increase in the amount of refrigerant circulating in the release circuit 15,
The amount of refrigerant circulated within the heating circuit 14 is offset and reduced, and an amount of refrigerant circulated that is in balance with the amount of combustion in the combustor 10 is obtained.

Further, when the heat load in the air-conditioned room (not shown) increases, the fuel supply control means 20 increases the fuel supply amount in order to increase the combustion amount, and the release control means 21 controls the release circuit 1 based on the signal.
5, thus reducing the amount of refrigerant circulating in the heating circuit 1.
The amount of refrigerant circulated within 4 increases and balances the amount of combustion.

In this way, the refrigeration cycle during the heating operation of the air conditioner (not shown) is always controlled to a stable operating state in response to fluctuations in the heat load of the air conditioned room (not shown), and therefore the compressor 1's workload also varies in response to the load, and its power consumption can also be made more efficient in response to the load.

Furthermore, if refrigerant leaks within the circuit 4 of the refrigeration cycle, the overall pressure within the heating circuit 14 will decrease. When the pressure drops below a certain set value, the pressure detection device 22 is activated and the fuel cutoff device 2 is activated.
A signal is sent to this so that 3 is activated. Upon receiving the signal, the fuel cutoff device 23 controls the fuel supply control means 2.
In response to this signal, the fuel supply control means 20 stops the fuel supply to the combustor 10. Therefore, the equipment forming the refrigeration cycle is not overheated, and damage to the equipment can be prevented.

Incidentally, the operation command signal of the release control means 21 is as follows:
Of course, the same effect as in the above embodiment can also be obtained by providing a means for detecting a temperature change of the refrigerant heated by the combustor and transmitting the signal from that means.

Further, the pressure detection device 22 is activated after the refrigeration cycle reaches steady operation in the heating circuit 14, and is not activated when the pressure in the circuit 14 increases at the time of startup.

〔Effect of the invention〕

As is clear from the above description, the present invention exhibits the following excellent effects.

(1) The amount of refrigerant released by the compressor can be controlled according to the amount of combustion in the combustor, and the refrigeration cycle can always be maintained in an appropriate state during heating operation.

(2) It is possible to reduce wasteful work of the compressor, reduce power consumption accordingly, and increase economic efficiency as much as possible.

(3) When refrigerant leaks, it is possible to prevent the combustor from burning in a dry state, and it is also possible to prevent damage to equipment.

(4) The control method is simple and can be easily adopted.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the configuration of a refrigeration cycle of an air conditioner in a conventional example of the present invention, and FIG. 2 is a circuit diagram showing the configuration of a refrigeration cycle of an air conditioner in an embodiment of the present invention. In the figure, 1 is a compressor, 10 is a combustor, 20 is a fuel supply control means, and 21 is a release control means.

Claims (1)

[Claims] 1. A compressor, an outdoor heat exchanger, a pressure reducing device, and an indoor heat exchanger are connected in sequence to form a refrigeration cycle, and the condensed refrigerant from the indoor heat exchanger is supplied to the refrigeration cycle during heating operation. A heating circuit is connected in which the refrigerant is passed through a heat exchanger for heating the refrigerant, where the condensed refrigerant is heated and evaporated and returned to the compressor, and a release circuit is connected in which a part of the refrigerant discharged from the compression side is bypassed to the suction side. In an air conditioner in which a heating heat exchanger is provided with a combustor that heats a refrigerant, there is provided a means for detecting a heat load in an air-conditioned room during heating operation, and a means for supplying fuel to the combustor according to fluctuations in the heat load. An air conditioner comprising: a fuel supply means that varies the amount of fuel; and a release control means that controls the amount of refrigerant released from the release circuit in accordance with the amount of fuel supplied by the fuel supply means. 2. The air conditioner according to claim 1, wherein the release control means detects the refrigerant outlet temperature of the refrigerant heating heat exchanger and controls the amount of refrigerant released according to the detected temperature. 3 A pressure detection device is installed on the suction side of the compressor,
The air conditioner according to claim 1, wherein the air conditioner stops combustion in the combustor of the refrigerant heating heat exchanger when the detected pressure becomes equal to or less than a set value.