JPS6032534Y2 - Heat recovery air conditioner - Google Patents

Description

[Detailed description of the invention] The present invention comprises a heat recovery type air conditioner, specifically a water heating heat exchanger, a water cooling heat exchanger, and an air side heat exchanger that operates as a condenser or an evaporator. The present invention relates to a heat recovery type air conditioner that is capable of performing cooling-only operation, cooling-priority operation, and heating-priority operation.

Conventionally, this type of air conditioner performs a heat recovery operation that simultaneously performs cooling and heating without using an air-side heat exchanger when the cooling load and heating load are the same size, or when the cooling load is larger than the cooling load, the air conditioner A cooling-priority operation in which the side heat exchanger is operated as an auxiliary condenser, and a cooling-only operation in which the air-side heat exchanger is operated as a condenser without using the water heating heat exchanger, and a heating load is performed when the cooling load is When the load is higher than the load, a heating-priority operation in which the air-side heat exchanger is operated as an auxiliary evaporator, and a heating-only operation in which the air-side heat exchanger is operated as an evaporator without using the water cooling heat exchanger are performed. I try to do it.

Further, in the above operation, in the case of heating priority or heating only operation in which the air side heat exchanger is used as an evaporator, the air side heat exchanger is frosted, and when frosting is performed, defrost operation is performed in addition to the above operation. We are also making it possible to do so.

Therefore, the water heating heat exchanger serves as a necessary condenser to heat the hot water when there is a heating load and heat recovery operation is performed simultaneously with cooling and heating. The exchanger functions as a condenser when the cooling load is greater than the heating load and the cooling is prioritized, when there is no heating load and the cooling is exclusively operated, and when the defrost operation is performed. However, the water heating heat exchanger is not used when there is no heating load and only cooling operation is performed, and the air side heat exchanger is not used when the cooling and heating loads are equally balanced. In this case, it is not used.

Therefore, when these are not in use, the liquid refrigerant may not flow into the water heating heat exchanger and the air side heat exchanger and may accumulate therein.

For this reason, it is necessary to increase the amount of refrigerant charged by considering the amount of refrigerant stored when not in use, and even if the amount of refrigerant charged is increased, the amount stored is not constant, so there is a problem of excess or deficiency of refrigerant. there were.

Therefore, the present invention was devised in view of the above-mentioned problems, and the purpose is to reduce the amount of refrigerant charged, and even when performing the above-mentioned balanced operation or cooling-only operation, there is no need to worry about excess or deficiency of refrigerant. The liquid receiver and the expansion mechanism are placed on the side between the outlet side of the water heating heat exchanger and the inlet side of the water cooling heat exchanger. A first bypass circuit is provided between the outlet side of the air side heat exchanger when the air side heat exchanger acts as a condenser and the inlet side of the water cooling heat exchanger. A second bypass circuit is provided for bypassing the container and the expansion mechanism, and a first solenoid valve is interposed in the first bypass circuit, which opens during cooling-only operation when the water heating heat exchanger is not in use. The second bypass circuit is characterized by interposing a second solenoid valve that opens when the air-side heat exchanger is not in use and the air-conditioning and heating loads are equally balanced.

In the present invention, the bypass circuit is arranged between the outlet side of the water heating heat exchanger and the inlet side of the water cooling heat exchanger, and between the outlet side of the air side heat exchanger when it functions as a condenser. Although it is preferable to provide two circuits between the water cooling heat exchanger and the inlet side, it is not necessary to provide two circuits, and even if one circuit is provided, it does not fall within the technical scope of the present invention. It is included.

Embodiments of the device of the present invention will be described below based on the drawings.

1 is a compressor, 2 is a water heating heat exchanger (hereinafter simply referred to as a condenser), 3 is a water cooling heat exchanger (hereinafter simply referred to as an evaporator), 4 is an air side heat exchanger, and 5 is a liquid receiver. , 6 are accumulators, and these devices are connected by refrigerant piping 7.

The compressor 1 has an unloader mechanism, and a hot water inlet thermostat detects the hot water inlet temperature of the condenser 2, and a cold water inlet thermostat detects the cold water inlet temperature of the evaporator 3, for example, 75%, 50%, Its compressive power is controlled in three stages of 25% capacity.

Further, 8 is a four-way switching valve, and 9 is a three-way valve, and these four-way switching valve 8 and three-way valve 9 control the flow of refrigerant discharged from the compressor 1, and the air-side heat exchanger 4 It is possible to perform cooling-only operation, cooling-priority operation, heating-only operation, heating-priority operation, balance operation, and frost operation.

The four-way switching valve 8 has a high pressure side port 81 and a low pressure side port 8.
2, and two first and second switching ports 83, 84, and the three-way valve 9 has one fixed port 91 and two first and second switching ports 83, 84. It has first and second control ports 92.93, and is configured such that the opening degrees of these control ports 92.93 can be adjusted, and the high pressure side port 81 of the four-way switching valve 8 is
The low pressure side port 82 is connected to the discharge port of the compressor 1 and the accumulator 6, the first switching port 83 is connected to the fixed port 91 of the three-way valve 9, and the second switching port 84 is connected to the condensing port 82. The first control port 92 of the three-way valve 9 is selectively connected to either the evaporator 3 or the condenser 2. Then, the second control port 93 is connected to the air side heat exchanger 4.

The three-way valve 9 controls the opening degree of the control port 92.93 from 0 to 100% by a control motor, and the four-way switching valve 8 switches the high-pressure gas refrigerant between the condenser 2 and the air side heat exchanger. It serves as a high-pressure side control valve that allows the low-pressure gas refrigerant evaporated in the evaporator 3 and the air-side heat exchanger 4 to flow at a predetermined ratio.

Therefore, when working as a high pressure side control valve, the opening degree to the condenser 2, that is, the opening degree of the first control port 92 is 100% to
When it is 0%, the opening degree to the air side heat exchanger 4, that is, the opening degree of the second control port 93 is 0 to 100%, and when the opening degree of the first control port 92 is 100%, the entire amount of high-pressure gas refrigerant is condensed. Vessel 2
When the air flows to the air side heat exchanger 4, it does not flow to the air side heat exchanger 4.

In the opposite case, it does not flow to the condenser 2.

Similarly, when working as a low-pressure side control valve, when the opening degree of the first control port 92 communicating with the evaporator 3 is 100 to 0%, the opening degree of the second control port 93 communicating with the air side heat exchanger 4 is 0 to 100%, the opening degree of the first control port 92 is 100%, and when the low-pressure gas refrigerant flows from the full-volume evaporator 3, the second control port 93 is closed and the liquid refrigerant flows to the air side heat exchanger 4. Never.

In the above configuration, the second switching port 84 of the four-way switching valve 8 is selectively connected to either the condenser 2 or the evaporator 3, and the first control port 92 of the three-way valve is connected to the second switching port 84 of the four-way switching valve 8.
selectively connected to either the condenser 2 or the evaporator 3, and the second switching port 84 and the first control port 9.
2 is reversibly connected to the condenser 2 and evaporator 3, and this connection method is based on the four check valves 10a to 1.
A four-port valve 10 such as a four-way check valve or a four-way switching valve is used.

In the figure, 11 is a temperature-sensitive expansion valve interposed in the middle of a liquid pipe 71 connecting the liquid receiver 5 and the evaporator 3, and 12 is a heat exchanger between the liquid receiver 5 and the air side heat exchanger. These expansion valves 11 and 12 are connected to a low-pressure gas pipe 73 and an equalizer pipe 74 that connects the three-way valve 9 and the air-side heat exchanger 4, which serve as low-pressure gas pipes. The pressure equalization circuit 13.14 has a pressure equalization circuit 13.14 which supplies high pressure liquid refrigerant to a pressure equalization chamber (not shown) in the expansion valve 11.12 which connects these pressure equalization circuits 13.14. However, a three-way solenoid valve 15.16 is interposed to forcibly close the expansion valve 11.12.

Reference numeral 17 denotes a bypass pipe interposed between the pressure equalization circuit 14 and the high-pressure liquid pipe portion of the liquid pipe 72 when the air side heat exchanger 4 becomes a condenser. is equipped with a check valve 18 and a high pressure regulating valve 19 that allow flow only to the high pressure liquid pipe section, and when the air side heat exchanger 4 is operated as a condenser, the high pressure is If the value is lower than the set value of the valve 19, the bypass pipe 17 is opened to send the uncondensed gas to the receiver 5, and the condensate is stored in the air side heat exchanger 4 to reduce the condensation pressure of the heat exchanger 14. It raises it.

The high pressure regulating valve 19 shown in the drawing uses a three-way valve called a head master to separate the high pressure liquid part.
It is connected to two ports 19a and 19b, and the bypass pipe 17 is connected to the remaining port 19c, and furthermore, the divided high-pressure liquid portion is connected by a short-circuit pipe 20.

Therefore, according to this configuration, the increase in the condensing pressure can be made slow, and the degree of increase can also be adjusted by selecting the diameter of the short-circuit pipe 20.

Further, 21 is a check valve installed in a liquid pipe 75 connecting the outlet of the condenser 2 and the liquid receiver 5, and 22 is a check valve installed between the air side heat exchanger 4 and the liquid receiver 5. This is a check valve installed in the liquid pipe 76 that connects the

Note that the liquid pipe 76 is a liquid pipe 72 in which the expansion valve 12 is interposed.
are connected in parallel, and the flow direction of the liquid refrigerant flowing through the liquid pipe 72 is from the liquid receiver 5 to the air side heat exchanger 4.
The flow direction of the liquid refrigerant flowing through the liquid pipe 76 is from the air side heat exchanger 4 to the liquid receiver 5.

That is, in heating-priority operation and heating-only operation in which the air-side heat exchanger 4 becomes an evaporator by switching the four-way switching valve 8, liquid refrigerant is supplied from the liquid receiver 5 through the liquid pipe 72 to the air. In cooling-priority operation and cooling-only operation, the liquid refrigerant flows to the side heat exchanger 4 and becomes an evaporator, and flows from the front heat exchanger 4 to the liquid receiver 5 via the liquid pipe 76.

Further, 23 is a bypass pipe that bypasses the check valve 21 between the liquid receiver 5 and the outlet of the condenser 2, and a solenoid valve 24 that opens during defrosting and acts as an expansion mechanism is inserted in the middle. I am wearing it.

Further, 25 is a bypass pipe provided between a short-circuit pipe 77 connecting the four-port valve 10 and the second switching port 84 of the four-way switching valve 8 and the inlet side of the condenser 2;
A solenoid valve 26, which opens during defrosting, is interposed in the middle.

The air conditioner shown in FIG. Valve 1
A first bypass circuit 27 that bypasses the liquid receiver 5 and the expansion valve 11 is provided between the low pressure liquid pipe 78 and the low pressure liquid pipe 78 between the air side heat exchanger 4 and the air side heat exchanger 4. Similarly to the first bypass circuit 27, a liquid receiver 5 and an expansion valve 11 are bypassed between the liquid pipe 76 between the outlet and the check valve 22 and the low pressure liquid pipe 78. A first bypass circuit 28 is provided, and the first bypass circuit 27 is provided with a first solenoid valve 29 that opens during cooling-only operation, and the second bypass circuit 28 is provided with a second solenoid valve 30 that opens during balance operation. .

In addition, as shown in FIG. 1, two bypass circuits 27.2
8 is preferable, but only one of the first and second bypass circuits 27 and 28 may be provided.

Further, when two bypass circuits 27, 28 are provided, each circuit 27, 28 may be connected to the low pressure liquid pipe 78, but they may be connected to the low pressure liquid pipe 78 as shown in FIG.
When connected to , the total circuit length can be shortened.

Next, the operation of the apparatus constructed as above will be explained.

When the four-way switching valve 8 is not energized, it is positioned as shown by the solid line in FIG. 1, and when energized, it is switched as shown by the dotted line in FIG. A low pressure gas refrigerant is introduced from the three-way valve, and this three-way valve acts as a high pressure side control valve to flow the high pressure gas refrigerant to the condenser 2 and the heat exchanger 4 at a predetermined ratio. At the dotted line position in Figure 1, the heat exchanger 4 serves as an evaporator, and the three-way valve 9 serves as a high-pressure side control valve to flow the low-pressure gas refrigerant evaporated in the evaporator 3 and the heat exchanger 4 at a predetermined ratio. This is how it works.

The switching judgment of the four-way switching valve 8 is based on the capacity of the compressor 1, which controls the capacity based on the cold water inlet or hot water inlet temperature, and the three-way valve that controls the opening degree of the first control port 92 based on the cold water outlet or hot water outlet temperature. This is done in relation to the opening degree of 9.

That is, in the cooling priority operation, the capacity of the compressor 1 is controlled by the cold water inlet temperature, and the opening degree of the three-way valve 9 is controlled by the hot water inlet temperature, and in the heating priority operation, the capacity of the compressor 1 is controlled by the hot water inlet temperature. , the opening degree of the three-way valve 9 is controlled based on the cold water outlet temperature, and the opening degree of the three-way valve 9 is 100%,
When the capacity of the compressor 1 is controlled, that is, in cooling-only operation, the hot water outlet temperature is lower than the set temperature of 42'C, the opening degree of the three-way valve 9 is 100%, and the entire amount of high-pressure gas refrigerant is used for water heating. When the cooling load is reduced and the chilled water inlet temperature becomes lower than the set temperature of 10° C. and the capacity of the compressor 1 is controlled to, for example, 75%, when the water is being sent to the condenser 2, the four-way switching valve 8 is In addition, in the heating priority operation, when the cold water outlet temperature is higher than the set temperature of 10° C. and the temperature of the three-way valve 9 is 100%, low pressure gas is discharged from the water cooling evaporator 3. When the full amount of refrigerant is flowing, the heating load decreases and the hot water inlet temperature reaches the set temperature of 42'
When the capacity of the compressor 1 is controlled to, for example, 75%, the power supply to the four-way selector valve 8 is interrupted and the operation is switched to cooling priority mode.

However, at startup, the cold water temperature is higher than the set temperature of 10℃,
When the hot water temperature is lower than the set temperature of 42°C, the four-way switching valve 8 is not energized and is positioned as shown in Fig. 1.
It starts with priority given to cooling.

At this time, if the cooling load (including compressor input) and heating load are equally balanced, the opening degree of the first control port 92 of the three-way valve 9 will be 100%, as shown by the thick line in Figure 1. The entire amount of the high-pressure gas refrigerant flows to the condenser 2 as shown by the solid line arrow and is condensed, heating the hot water and
The entire amount of the condensed liquid refrigerant enters the evaporator 3 via the liquid receiver 5 and the expansion valve 11, cools the cold water, and returns to the compressor 1 via the four-way switching valve 8, forming a refrigeration cycle. , balance operation is performed in a cooling-priority operation system.

At this time, the air side heat exchanger 4 is not used, the solenoid valve 30 is opened, and the heat exchanger 4 is communicated with the low pressure liquid pipe 78 via the second bypass circuit 28.
The liquid refrigerant accumulated in the heat exchanger 4 is recovered as indicated by the dotted arrow.

Since this recovery is performed from the liquid pipe 76, the heat exchanger 4
No evaporation takes place inside.

Therefore, there is no frost formation or dew condensation, and even if the high-pressure gas refrigerant leaks from the three-way valve 9, it can be reliably recovered.

Furthermore, since the recovery is carried out through the low-pressure liquid pipe 78 and the evaporator 3, there is no need to worry about liquid back-up while recovering the liquid refrigerant.

Next, when the heating load becomes smaller or the cooling load increases and the hot water outlet temperature rises, the hot water outlet temperature causes the first control port 92 of the three-way valve 9 to open. The temperature decreases from 100%, the second control port 93 opens by the amount of the decrease, and cooling priority operation is performed.

That is, the high-pressure gas refrigerant guided to the three-way valve 9 flows to the condenser 2 and the air-side heat exchanger 4 depending on the degree of opening of the three-way valve, and the high-pressure gas refrigerant flows to the condenser 2 and the air-side heat exchanger 4. It condenses.

The liquid refrigerant condensed as described above joins in the liquid receiver 5 and returns to the compressor 1 via the above-mentioned path. is operated at 100% load.

If the above state continues and the heating load disappears, the opening of the first control port 92 of the three-way valve 9 becomes 0% and closes, and the second control port 93 becomes 100% and closes. As shown by the bold line in the figure, the entire amount of the high-pressure gas refrigerant flows to the air-side heat exchanger 4 as indicated by the solid arrow, and hot water heating in the condenser 2 is stopped, and cooling-only operation is performed.

During this cooling-only operation, the condenser 2 is not used, so the solenoid valve 29 is opened, and the condenser 2 is
It communicates with a low-pressure liquid pipe 78 via a bypass circuit 27, and recovers the liquid refrigerant accumulated in the condensing device 2 as shown by the dotted arrow.

Since this recovery is also performed from the liquid pipe 75 as described above, the condenser 2
There is no evaporation effect, so the hot water does not freeze, and there is no need to worry about liquid back-up.

Also, from the state of simultaneous cooling and heating operation in the cooling priority operation system shown in Figure 1, contrary to the above, the hot water outlet temperature is set to 4.
If the cooling load becomes small even though the temperature is lower than 2'C, and the chilled water inlet temperature becomes lower than the set temperature of 10C, the second
The capacity of the compressor 1 is controlled while maintaining the valve opening of the control port 92 at 100%.

That is, the capacity of the compressor 1 in the operation regime is controlled by the cold water inlet temperature, so if the cold water inlet temperature is low, for example 9°C, the cold water inlet thermostat will work to reduce the load 7.
Controlled to 5%.

Therefore, the four-way switching valve 8 is energized, and the four-way switching valve 8 is switched to the first
The camera is switched to the position shown by the dotted line in the figure.

By switching the four-way switching valve 8, the entire amount of high-pressure gas refrigerant flows to the condenser 2 via the four-port valve 10 and is condensed, heating the hot water, and the condensed liquid refrigerant is transferred from the receiver 5 to One part passes through the expansion valve 11, enters the evaporator 3, and evaporates, and the other part passes through the expansion valve 12, enters the air-side heat exchanger 4, and evaporates.The evaporated low-pressure gas refrigerant is distributed at a predetermined ratio. Then, the cycle is switched from the three-way valve 9 to the refrigeration cycle which returns to the compressor 1 via the four-way switching valve 8, and the heating priority operation is performed.

When switched to this heating priority operation, the three-way valve 9
The opening degree of the compressor 1 is controlled by a cold water outlet thermometer which serves as a low pressure side control valve and detects the cold water outlet temperature, and the capacity of the compressor 1 is controlled by a hot water inlet thermometer.

Next, in the above state, if the cooling load decreases and the chilled water outlet temperature falls further below, for example, 6° C., the opening degree of the first control port 92 of the three-way valve 9 decreases and approaches 0%. When the opening degree is 0%, it will operate exclusively for heating.

That is, when the first control port 92 is closed with an opening degree of 0%, the opening degree of the second control port 93 becomes 100%, and the liquid refrigerant condensed in the condenser 2 is transferred from the liquid receiver 5 to the air side heat exchanger. 4
After evaporation, the entire amount of the low-pressure gas refrigerant passes through the three-way valve 9 and returns to the compressor 1 from the four-way switching valve 8, forming a refrigeration cycle.

Furthermore, in the heating priority operation described above, when the cooling load including the compressor input and the heating load are equally balanced, the opening degree of the first control port 92 of the three-way valve 9 is 100%, as shown in FIG. As shown by the thick line, the entire amount of the high-pressure gas refrigerant flows from the four-way switching valve 8 to the condenser 2 as shown by the solid line arrow, heating the hot water, and the condensed liquid refrigerant flows through the expansion valve of the liquid receiver 5. 11, the entire amount flows to the evaporator 3 to cool the cold water, and the entire amount of the evaporated low-pressure gas refrigerant passes through the three-way valve 9, returns to the compressor 1 from the four-way selector valve 8, and is in a heating priority operation system. A balanced operation is carried out.

In this case as well, the electromagnetic valve 30 is opened and the liquid refrigerant accumulated in the air side heat exchanger 4 is recovered as indicated by the dotted arrow in the same manner as in the above-mentioned balance operation.

Furthermore, in the above-mentioned heating priority operation and heating only operation, if the air-side heat exchanger 4, which functions as an evaporator, becomes frosted, a defrost operation can also be performed. The switch is switched to the solid line position in the figure, the high pressure port 81 is communicated with the first switching port 83, the high pressure gas refrigerant is flowed to the three-way valve 9, and the entire amount of the high pressure gas refrigerant is flowed from the three-way valve 9 to the air side heat exchanger 4. This latent heat of condensation is used for defrosting.

During defrosting, the electromagnetic valves 24 and 26 are opened, and the liquid refrigerant condensed in the heat exchanger 4 is allowed to flow from the receiver 5 to the water heating condenser 2 via the bypass pipe 23 and evaporated. The low-pressure gas refrigerant is returned to the compressor 1 from the bypass pipe 25 and the communication pipe 77 via the four-way switching valve 8.

In this defrost cycle, the solenoid valve 24 acts on the expansion valve during one period, and by selecting the capacity of this solenoid valve 24, the low pressure during the defrost operation can be increased, and therefore the low pressure can be shortened. You can finish defrosting in a matter of hours.

As described above, when the water heating heat exchanger or air side heat exchanger serving as a condenser is not used, these heat exchangers are connected to the low pressure between the inlet of the water cooling heat exchanger and the expansion mechanism. Since the refrigerant is recovered by communicating with the liquid region, it is possible to prevent the refrigerant from accumulating in the heat exchanger when it is not used, and therefore the amount of refrigerant to be charged can be reduced. Since the amount of refrigerant circulating when there is no refrigerant can be kept constant without excess or deficiency, stable operation can be performed.

Moreover, if the operation pattern is changed when the operation of the air conditioner is stopped, for example, if the operation is stopped while the air conditioner is in cooling-only operation, the operation pattern can be changed at the same time as the operation is stopped. By switching to cooling/heating equilibrium operation, the air-side heat exchanger, which was at high pressure during the cooling-only operation, becomes low pressure at the same time as the operation is stopped, and high and low pressures can be equalized. In other words, the pressure equalization time is As a result, the time from stop to restart can also be shortened.

Furthermore, since the refrigerant is recovered in a low-pressure liquid region, the heat exchanger is not cooled, and since the refrigerant to be recovered is evaporated in the water-cooling heat exchanger, there is no need to worry about liquid back-up.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant piping system diagram showing one embodiment of the device of the present invention;
FIGS. 2 and 3 are refrigerant piping system diagrams explaining the operation. 1... Compressor, 2... Heat exchanger for water heating, 3... Heat exchanger for water cooling, 4...
Air side heat exchanger, 5...Liquid receiver, 11.12.
...Expansion mechanism, 27, 28...Bypass circuit, 29...11th! ! Magnetic valve, 30...
...Second solenoid valve.

Claims (2)

[Scope of utility model registration request] (1) Compressor, water heating heat exchanger, water cooling heat exchanger,
In a heat recovery air conditioner comprising an air-side heat exchanger, a liquid receiver, and an expansion mechanism, the air-side heat exchanger can be operated as a condenser or an evaporator for simultaneous cooling and heating, wherein the water heating heat exchanger A first bypass circuit bypassing the liquid receiver and the expansion mechanism is provided between the outlet side of the water cooling heat exchanger and the inlet side of the water cooling heat exchanger, and the air side heat exchanger acts as a condenser. A second bypass circuit for bypassing the liquid receiver and the expansion mechanism is provided between the outlet side of the heat exchanger and the inlet side of the water cooling heat exchanger, and the second bypass circuit bypasses the liquid receiver and the expansion mechanism. A first solenoid valve that opens during cooling-only operation, which is when the water heating heat exchanger is not in use, is interposed in the circuit, and the second bypass circuit has an equal air-conditioning load when the air-side heat exchanger is not in use. A heat recovery type air conditioner characterized by being equipped with a second solenoid valve that opens during balanced operation. (2) The connection sides of the first bypass circuit and the second bypass circuit to the inlet side of the water cooling heat exchanger are joined in the middle of the first and second bypass circuits, and the first bypass circuit and the second bypass circuit are connected to the inlet side of the water cooling heat exchanger. The heat recovery type air conditioner according to claim 1, wherein the first and second solenoid valves installed in the second bypass circuit are located before the confluence point.