JPH0526542A - Air conditioner - Google Patents

Abstract

PURPOSE:To operate an air conditioner while keeping its heating function and defrosting function in a well-balanced state during defrosting operation and reduce the dimensions of a heat accumulating tank. CONSTITUTION:In an air conditioner 1, a flow path of a refrigerant is changed over by switching an expansion valve B, a solenoid valve and a three-way valve 15 and disposing check valves 16, 17 at respective times when heating operation only is performed (arrow shown by solid line) and when heating operation and defrosting operation are simultaneously performed (arrow shown by broken line). By this method, a compact common heat exchanger 12 constituted of a common refrigerant tube instead of refrigerant tubes for giving heat and for receiving heat can be provided in a heat accumulating tank 3. Further, a part of the refrigerant at a high temperature, which is discharged from a compressor 2, is caused to flow through a capillary tube 6 so as to bypass a condenser 4 and a capillary tube 5; therefore, flow path resistance in the capillary tubes 5, 6 can be suitably set, respectively, so that heating function and defrosting function can be well balanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a refrigeration cycle having a heat storage tank, and uses the heat stored in the heat storage material of the heat storage tank to heat the interior of the room while defrosting the frost adhering to the evaporator. Regarding air conditioners.

[0002]

2. Description of the Related Art FIG. 5 shows a refrigeration cycle of _a heat pump type air conditioner 1a which is an example of this type of air conditioner. In the illustrated state of the air conditioner 1 _a, the heating operation mode is set by switching the flow path of the four-way valve 19. During the heating operation, the first solenoid valve 18 is closed and the second solenoid valve 18 is closed.
The solenoid valve 21 of is open. Therefore, refrigerant discharged from the compressor 2 high temperature heat storage tank 3 _a heat heat exchanger 10 given the
The heat is stored in the heat storage material 20 by the four-way valve 19, the indoor condenser 4, the expansion valve 28, the outdoor evaporator 9, the four-way valve 19, the solenoid valve 21, and the compressor 2 in this order, as indicated by the solid arrow, It circulates in the refrigerant pipe 30 to heat the room. At this time, if the outside air temperature is low, frost may adhere to the surface of the evaporator 9 to lower the heating capacity. Therefore, it is necessary to appropriately defrost the surface of the evaporator 9. Therefore, the heat storage tank 3 _a is connected to the refrigerant pipe 30 of the refrigeration cycle, whereby, so as to shorten the defrosting time with increasing heating capacity during the defrosting operation. As shown in FIG. 6, in the heat storage tank 3 _a , the heat exchanger 10 for heating and the heat exchanger 11 for heat reception described later are housed in a heat storage material 20 in the tank. Therefore, when the defrosting operation and the heating operation are simultaneously performed, the solenoid valve 18 is opened and the solenoid valve 21 is closed. Then, the refrigerant discharged from the compressor 2 bypasses the expansion valve 28, flows through the electromagnetic valve 18, and is guided to the evaporator 9, as indicated by a dashed arrow. At this time, the refrigerant is not greatly decompressed in the solenoid valve 18, so the evaporator 9 is heated at a relatively high temperature. Thereby, the evaporator 9 is defrosted. The refrigerant condensed in the condenser 4 and the evaporator 9 is decompressed in the capillary tube 7 and partially vaporized, and then the heat stored in the heat storage material 20 of the heat storage tank 3 _a is transferred to the heat receiving heat exchanger 11 After being taken out and completely vaporized, it is returned to the compressor 2.

[0003]

By the way, the pressure (condensation pressure) when the refrigerant in the evaporator 9 frosted on the surface is condensed becomes a saturation pressure corresponding to a frost temperature of 0 ° C. or less, for example. ， Relatively low. Therefore, when the solenoid valve 18 having a sufficiently small refrigerant pressure loss is adopted, the refrigerant in the condenser 4 has the same low pressure as in the evaporator 9 and is less likely to condense. Therefore, the heating capacity during defrosting operation is extremely small. On the contrary, if the solenoid valve 18 with a large refrigerant pressure loss is adopted in order to increase the pressure in the condenser 4 and increase the heating capacity, the refrigerant will be cooled by the condenser 4.
Most of them are condensed, and the vapor-liquid two-phase refrigerant having a large liquid ratio flows into the evaporator 9. Therefore, the defrosting ability that depends on the latent heat of condensation of the refrigerant is extremely small. Therefore, the defrosting time will be extended. Thus, the conventional air conditioner 1 _a includes a were unbalanced heating capacity and defrosting capacity in the defrosting operation. On the other hand, was also a demand for a compact thermal storage tank 3 _a that require relatively space. Therefore, an object of the present invention is to provide an air conditioner capable of performing a well-balanced operation of the heating capacity and the defrosting capacity during the defrosting operation and making the heat storage tank compact. Especially.

[0004]

In order to achieve the above object, the main means adopted by the present invention are, as its gist, a compressor, a heat storage tank, a condenser on the indoor side, a throttle mechanism and an outdoor side. A refrigeration cycle is provided in which the evaporators are connected in this order through the refrigerant pipes, and the heat stored in the heat storage tank is taken out from the heat-supplying refrigerant pipes of the heat storage tank and taken out from the heat-receiving refrigerant pipe. In an air conditioner that defrosts the evaporator while performing heating, a heat storage tank in which the heating and receiving refrigerant pipes are formed by a common refrigerant pipe, and the condenser and throttle mechanism and the heat storage tank A refrigerant flow path switching means for changing the order of refrigerant flow, and a refrigerant bypass means connected in parallel to the condenser and the throttling mechanism to the refrigeration cycle and allowing the refrigerant to flow by bypassing the condenser and the throttling mechanism. Air conditioning related to It is configured as.

[0005]

In the air conditioner of the present invention, for example, in the case of only the heating operation and in the case of simultaneously performing the heating operation and the defrosting operation, the refrigerant flow order of the condenser / throttle mechanism and the heat storage tank is switched between the refrigerant flow paths. It is replaced by means. Therefore, a common refrigerant pipe is used for heating and receiving heat of the heat storage tank, and thus the heat storage tank becomes compact. On the other hand, when the heating operation and the defrosting operation are performed at the same time, a part of the high temperature refrigerant from the compressor circulates around the condenser and the throttle mechanism. As a result, the heat of the part of the refrigerant is used for defrosting the evaporator without being released in the condenser.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. The following embodiments are examples of embodying the present invention and are not of the nature to limit the technical scope of the present invention. 1 is a block diagram showing a refrigeration cycle of an air conditioner according to an embodiment of the present invention, FIG. 2 is a perspective view showing a shared heat exchanger used in a heat storage tank of the air conditioner, and FIG. 2 is a Mollier diagram showing the pressure-enthalpy behavior of the air conditioner, and FIG. 4 is a state explanatory view showing a state in which the shared heat exchanger viewed in the direction of arrow G in FIG. However, the same reference numerals are used for the elements common to the above-described conventional air conditioner 1 _a shown in FIG. 5, and the detailed description thereof will be omitted. In the refrigeration cycle of the air conditioner 1 according to the present embodiment, as shown in FIG. 1, the compressor 2, the three-way valve 15, the four-way valve 19, the condenser 4, the expansion valve 8, the evaporator 9, and the four-way valve 19 are sequentially arranged. Refrigerant pipe 30
Are connected via. Further, in parallel with the expansion valve 8, a capillary tube 5, a check valve 16, a common heat exchanger 12, and a solenoid valve 13 are sequentially connected to the refrigeration cycle, and the check valve 16 and the common heat exchanger 12 are connected to each other. The connecting refrigerant pipe and one refrigerant outlet of the three-way valve 15 are connected,
A refrigerant pipe connecting the shared heat exchanger 12 and the electromagnetic valve 13 and a refrigerant pipe connecting the other refrigerant outlet of the three-way valve 15 and the four-way valve 19 are connected via a check valve 17.
Further, the refrigerant pipe at one refrigerant outlet of the three-way valve 15 and the refrigerant pipe at the other refrigerant outlet are connected via a capillary tube 6. That is, the capillary tube 6 and the refrigerant pipe connected thereto are the refrigerant bypass means according to the present invention. The common heat exchanger 12 is, as shown in FIG.
One refrigerant pipe 30 that is bent multiple times has a large number of cooling fins 2.
It is fixed by being inserted into 5. The shared heat exchanger 12 is arranged in the heat storage tank 3 in the heat storage material 20 made of, for example, polyethylene glycol, paraffin, sodium acetate trihydrate or the like (FIG. 4). The refrigerant tube provided with the capillary tube 6 is provided so as to balance the heating capacity and the defrosting capacity during the defrosting operation, and the condenser 4 and the capillary tube 5 (throttle mechanism). ) In parallel with the above refrigeration cycle.

The air conditioner 1 of this embodiment is constructed as described above. The air conditioner 1 is of a heat pump type and can perform a cooling operation by switching the flow path of the four-way valve 19, but the heating operation will be described below. Therefore, when performing the heating operation, the three-way valve 15 opens the flow path to the heat storage tank 3, and the solenoid valve 13 is closed.
Therefore, the high-temperature refrigerant discharged from the compressor 2 heats the heat storage material 20 in the common heat exchanger 12, and then the check valve 1
7, the four-way valve 19, the condenser 4, the expansion valve 8, the evaporator 9, and the four-way valve 19 are returned to the compressor 2 (solid arrow). On this occasion,
The refrigerant absorbs heat from the outside air in the outdoor evaporator 9, heats the room in the indoor condenser 4, and heat-storage material 2
Stores heat to 0. On the other hand, when performing the defrosting operation while performing the heating operation, the expansion valve 8 is fully closed, the three-way valve 15 is switched to open the flow path to the four-way valve 19, and the solenoid valve 13 is turned on. Be released. As a result, the order of refrigerant flow between the condenser 4, the capillary tube 5, or the expansion valve 8 (both throttle mechanisms) and the shared heat exchanger 12 of the heat storage tank 3 is exchanged with respect to the case of only the heating operation. .. Therefore, the refrigerant discharged from the compressor 2 radiates heat in the condenser 4 via the four-way valve 19 and is condensed, and thereafter, the heat is absorbed from the heat storage material 20 in the common heat exchanger 12 through the capillary tube 5 and the check valve 16. Then, the temperature rises to a high temperature, and further returns to the compressor 2 through the solenoid valve 13, the evaporator 9, and the four-way valve 19 (broken arrow). As a result, the defrosting operation is performed while continuing the heating operation. The check valve 16 is provided to prevent the refrigerant discharged from the compressor 2 from flowing into the expansion valve 8 through the capillary tube 5 during the heating operation, and the check valve 17 is provided in the defrosting operation. Inside the compressor 2
It is provided in order to prevent the refrigerant from the above from flowing into the solenoid valve 13. That is, the structure comprising the expansion valve 8, the solenoid valve 13, the three-way valve 15, the check valves 16 and 17, and the refrigerant pipes connected to them is the refrigerant flow path switching means according to the present invention.

The state of the refrigerant when the heating operation and the defrosting operation as described above are used together is shown in the Mollier diagram of FIG. In the figure, points A to F correspond to the states of the refrigerant at positions A to F of the refrigerant pipe in FIG. According to this Mollier diagram, during defrosting, the refrigerant (A) from the compressor 2 dissipates and condenses in the condenser 4 to become the state of (B), and then passes through the capillary tube 5 to be in a depressurized state. It becomes (C). Subsequently, this refrigerant is heated in the shared heat exchanger 12 to a high temperature state (D), and then part of the evaporator 9 dissipates heat and condenses to melt the frost on the surface of the evaporator 9 ( The flow of the cycle line Q, which becomes E) and returns to the compressor 2, is formed. However, as described above, since the bypass flow path provided with the capillary tube 6 is provided, a bypass flow indicated by the cycle line q is added in addition to the flow of the cycle line Q which is the main flow at the time of actual defrosting. Will be done. At this time, the ratio of the refrigerant flow amount of the cycle line Q and the refrigerant flow amount of the cycle line q is determined by the ratio of the flow channel resistances of the capillary tube 5 and the capillary tube 6, and the total of these is determined. Circulation amount is
It is determined by the sum of both flow path resistances. Therefore, when the defrosting capacity is increased, the flow path resistance of the capillary tube 6 is made smaller than that of the capillary tube 5, and when the heating capacity is increased, conversely, the flow path resistance of the capillary tube 5 is set small. Good. Further, in order to adjust the total amount of refrigerant circulation, the above-mentioned capillary tubes 5, 6 are used.
In addition to the flow path resistance of, for example, the flow path resistance of the solenoid valve 13 may be set to a required value.

As described above, according to this embodiment, the heating capacity and the defrosting capacity during the defrosting operation can be balanced. As a result, for example, the evaporator 9 can be defrosted in a short time while performing a heating operation with a large capacity. Further, since the heat exchanger 10 for heating and the heat exchanger 11 for receiving heat as in the conventional case are shared by the single common heat exchanger 12, the heat storage material 20 accommodated in the heat storage tank 3 requires a small amount. In addition, it has a great advantage that the heat storage tank 3 can be made compact. The temperature distribution curve T ₁ during heat storage and the temperature distribution curve T ₂ during heat dissipation in the shared heat exchanger 12 are shown in FIG.
Shown in. The area of the shaded area surrounded by the respective temperature distribution curves T ₁ and T ₂ corresponds to the amount of heat input and output to and from the heat storage material, which is the same as the conventional heat exchanger 10 for heat application and heat exchange for heat reception. The heat input / output amount (Fig. 6) represented by the shaded area surrounded by the temperature distribution curves T ₁₁ and T ₁₂ at the time of heat storage and heat dissipation formed by the heat exchanger 11 is almost the same, and the size of the heat exchanger is small. It shows that the heat exchange efficiency does not change despite the fact that it was attempted. In the above embodiment, the refrigerant discharged from the compressor is always circulated in the common heat exchanger 12 only during the heating operation, but the present invention is not limited to this, and the three-way valve can be switched at appropriate times. The amount of heat stored by the discharged refrigerant can also be controlled. Further, the expansion valve 8 is configured to be fully closed during the defrosting operation, but instead of this,
It is also possible to use a combination of a capillary tube and a fully closed and fully opened solenoid valve. Further, in the above-described embodiment, the capillary tube 5 and the capillary tube 6 having the preset flow path resistance are provided. However, the capillary tube 5 or the capillary tube 6 or both of them are replaced, and the expansion of the variable amount of refrigerant flow is performed. A valve may be used. This makes it possible to finely adjust the balance between the heating capacity and the defrosting capacity during operation.

[0010]

As described above, the present invention provides a refrigeration cycle in which a compressor, a heat storage tank, an indoor condenser, a throttle mechanism and an outdoor evaporator are connected in this order through a refrigerant pipe. In the air conditioner for defrosting the evaporator while heating the room by taking out the heat stored in the heat storage tank from the heat supply refrigerant tube from the heat storage tank, Storage tank in which the refrigerant tubes for heat reception and heat reception are constituted by a common refrigerant tube, refrigerant flow path switching means for switching the refrigerant circulation order between the condenser and the throttling mechanism and the heat storage tank, and the condenser and the throttling mechanism. Since the air conditioner is connected in parallel to the refrigeration cycle and is provided with a refrigerant bypass means that allows the refrigerant to flow by bypassing the condenser and the throttling mechanism, the heating during the defrosting operation is achieved. Balance between defrosting ability and defrosting ability After which it is possible to perform the operation, it may be made compact in the heat storage tank.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a refrigeration cycle of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a common heat exchanger used in the heat storage tank of the air conditioner.

FIG. 3 is a Mollier diagram showing the pressure-enthalpy behavior of the air conditioner.

FIG. 4 is a state explanatory view showing a state in which the shared heat exchanger viewed in the direction of arrow G in FIG. 2 is housed in a heat storage tank.

FIG. 5 is a configuration diagram showing a refrigeration cycle of a conventional air conditioner as an example of the background of the present invention.

FIG. 6 is a state explanatory view showing a state inside the heat storage tank of FIG.

[Explanation of symbols]

1, 1 _a ... Air conditioner 2 ... Compressor 3, 3 _a ... Heat storage tank 4 ... Condenser 5 ... Capillary tube (throttle mechanism) 6 ... Capillary tube 7 ... Capillary tube 8 ... Expansion valve (throttle mechanism) 9 ... Evaporation Heater 10 ... Heat exchanger for heating 11 ... Heat exchanger for receiving heat 12 ... Common heat exchanger 13 ... Solenoid valve 15 ... Three-way valve 16, 17 ... Check valve 30 ... Refrigerant pipe

Claims (1)

Claim: What is claimed is: 1. A refrigeration cycle comprising a compressor, a heat storage tank, an indoor condenser, a throttle mechanism, and an outdoor evaporator, which are connected in this order through a refrigerant pipe, In an air conditioner that defrosts the evaporator while heating the interior of the room by taking out the heat stored in the heat storage tank from the heat transfer refrigerant tube from the heat receiving refrigerant tube, A heat storage tank in which a refrigerant pipe for heat reception is formed by a common refrigerant pipe, a refrigerant flow path switching means for switching the order of refrigerant flow between the condenser and the throttling mechanism, and the heat storage tank, and in parallel with the condenser and the throttling mechanism. An air conditioner connected to the refrigeration cycle, comprising: a refrigerant bypass means for allowing a refrigerant to flow by bypassing the condenser and the throttle mechanism.