JPS6045345B2 - Heat recovery air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a heat recovery air conditioner, in particular, comprising a compressor, a water heating condenser, a water cooling evaporator, and an air-side heat exchanger functioning as a condenser or an evaporator, This invention relates to a heat recovery type air conditioner that can perform heating and cooling at the same time.

Conventionally, in an air conditioner, a three-way valve having three ports, one fixed port and two first and second control ports, is used, and the first control port of the three-way valve is connected to the evaporator. Furthermore, in addition to the heat recovery operation in which the second control port is connected to the heat exchanger to simultaneously perform cooling and heating, there is also a cooling priority operation in which the heat exchanger is operated as an auxiliary condenser when the cooling load is greater than the heating load. When the heating load is larger than the cooling load, the heat exchanger is operated as an auxiliary evaporator to perform a heat recovery operation giving priority to heating.

Among the above operation modes, when performing a heating-priority heat recovery operation in which the air-side heat exchanger is used as an auxiliary evaporator, there is no cooling load and the air-side heat exchanger is
There is no problem when the refrigerant is flowing, but when there is a cooling load and the flow is divided between the air side heat exchanger and the water cooling evaporator, the refrigerant flow to the air side heat exchanger is particularly bad. When the flow rate is low, the refrigerant flow rate is also slow, and as a result, the circulating oil that is mixed into the refrigeration cycle system and circulated together with the refrigerant is no longer transported and accumulates in the heat exchanger over time. There was a problem of oil shortage.

Therefore, the present invention was invented to solve the above problems, and has a simple structure without any special mechanism.
This was done to eliminate the oil stagnation during the heat recovery operation that prioritizes heating.

That is, in the present invention, oil pools are formed in the heat exchanger because:
Focusing on the fact that the cause is a low refrigerant flow rate and a slow refrigerant flow rate, and that the oil stagnation occurs over time, in heat recovery operation that prioritizes heating, the first and second three-way valves are When the two control ports are connected to the water cooling evaporator and the air side heat exchanger, measure the time, and after a certain period of time, an oil stagnation occurs and the oil is insufficient. After a period of time (for example, 1 hour) during which
The control boat was closed and the entire amount of refrigerant was allowed to flow through the heat exchanger for a certain period of time (for example, one drop) to circulate the oil accumulated in the heat exchanger.

That is, the present invention operates when the first and second control boats 92 and 93 of the three-way valve 9 detect that both control boats are open, which are in communication with the evaporator 3 and the heat exchanger 4, respectively. A detection device 20 is provided, time measurement is started by the operation of the detection device 20, and after a certain period of time, a command is issued to the three-way valve 9 to close the first control boat 92, and the command is maintained for a certain period of time. The present invention is characterized in that it includes a refrigerant flow control circuit A.

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

1 is a compressor, 2 is a condenser for water heating, 3 is an evaporator for water cooling, 4 is an air side heat exchanger, 5 is a liquid receiver, and 6 is an accumulator, and these devices are connected to refrigerant piping 7. So, each has been contacted.

The compressor 1 has an unloader mechanism, and has a hot water inlet thermometer Th2 that detects the hot water inlet temperature of the condenser 2, and a cold water inlet thermometer '1111 that detects the cold water inlet temperature of the evaporator 3. %, 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.The four-way switching valve 8 and the three-way valve 9 control the flow of refrigerant discharged from the compressor 1, and the flow of the refrigerant discharged from the compressor 1 is controlled by the four-way switching valve 8 and the three-way valve 9. The side heat exchanger 4 can be used as a condenser, an evaporator, or no refrigerant flows, and can perform cooling-only operation, cooling-priority operation, heating-only operation, heating-priority operation, simultaneous heating and cooling operation, and defrost operation. So do it.

The four-way switching valve 8 uses an existing four-way switching valve having four boats: a high-pressure side boat 81, a low-pressure side boat 82, and two first and second switching boats 83 and 84. Further, the three-way valve 9 has one fixed boat 91 and two first and second control boats 92, 93, and is configured to be able to adjust the opening degrees of these control boats 92, 93. The high pressure side boat 81 of the four-way switching valve 9
are connected to the discharge port of the compressor 1, a low-pressure side boat 82, and the accumulator 6, respectively, and the first switching boat 83 is connected to the fixed boat 91 of the three-way valve 9, and the second switching boat 84 is connected to the discharge port of the compressor 1. The first control boat 92 of the three-way valve 9 is selectively connected to either the condenser 2 or the evaporator 3, and the first control boat 92 of the three-way valve 9 is selected as either the evaporator 3 or the condenser 2. The second control boat 93 is connected to the air side heat exchanger 4.

The three-way valve 9 controls the opening degree of the control boats 92 and 93 from 0 to 100% using a control motor, and switches the high-pressure gas refrigerant between the condenser 2 and the air side by switching the four-way switching valve 8. It serves as a high-pressure side control valve that allows the low-pressure gas refrigerant evaporated between the evaporator 3 and the air-side heat exchanger 4 to flow at a predetermined ratio. It is something to do.

Therefore, when working as a high pressure side control valve, the condenser 2
That is, the opening degree of the first control boat 92 is between 100% and 0.
%, the opening degree to the air side heat exchanger 4, that is, the opening degree of the second control boat 93 is 0 to 100%, and the opening degree to the first control boat 9 is 0 to 100%.
When the opening degree of 2 is 100% and the entire amount of high-pressure gas refrigerant flows to the condenser 2, it does not flow to the air side heat exchanger 4.

In the opposite case, it does not flow to the condenser 2. The same applies to the case where it functions as a low-pressure side control valve. When the opening degree of the first control boat 92 passing through the evaporator 3 is 100 to 0%, the opening degree of the second control boat 93 passing through the air side heat exchanger 4 is the same. Degree is O~100%
Therefore, when the opening degree of the first control boat 92 is 100% and low-pressure gas refrigerant flows from the full-volume evaporator 3, the second control boat 93 is closed and no liquid refrigerant flows into the air-side heat exchanger 4.

In the above configuration, the second switching boat 84 of the four-way switching valve 8 is selectively connected to either the condenser 2 or the evaporator 3, and the first control boat 92 of the three-way valve is connected to
selectively connected to either the condenser 2 or the evaporator 3, and the second switching boat 84 and the first control boat 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-way switch valve in combination with 0d or a four-boat valve such as a four-way switching valve (not shown) is used.

In the figure, 11 is a temperature-sensitive expansion valve interposed in the middle of the liquid pipe 71 connecting the liquid receiver 5 and the evaporator 3, and 12 is the air side heat exchanger between the liquid receiver 5 and the air side heat exchanger. It is a temperature-sensitive expansion valve interposed in the middle of the liquid pipe 72 connecting between 13 and 13.
, 14 are check valves.

Furthermore, when the coil is not energized, the four-way switching valve 8 is located at the solid line position in FIG. 1, putting the refrigeration cycle in cooling priority operation, and when energized, it is switched to the second solid line position, and heating priority operation is performed. At startup, if the cold water temperature is higher than the set temperature and the hot water temperature is lower than the set temperature, the relay R1, which is controlled by the cold water inlet thermo Tll and the hot water inlet thermo Th2, and connected to the coil is energized. Therefore, the four-way switching valve 8 is located at the position shown by the solid line in FIG. 1, so that cooling is given priority.

In this cooling priority operation, when the cold water inlet temperature becomes lower than the set temperature even though the hot water outlet temperature is lower than the set temperature, the relay R1 is energized and the four-way switching valve 8
is switched to the position shown by the solid line in Figure 2, giving priority to heating operation.
The opening degree of the three-way valve 9 is controlled by the hot water outlet temperature using the hot water outlet thermometer '1114 in the cooling priority operation, and by using the cold water outlet thermometer Th3 in the heating priority operation. I will do it.

Capacity control of the compressor 1 is performed by the cold water inlet temperature using the cold water inlet thermometer Thl in the cooling priority operation, and by the hot water inlet thermometer Th in the heating priority operation.
2 and the hot water inlet temperature. However, in the above configuration, when the first and second control boats 92 and 93 of the three-way valve 9 detect the open state of both control boats communicating with the evaporator 3 and the heat exchanger 4, respectively, the operation is performed. A detecting device 20 is provided, and the detecting device 20 starts measuring time by operating the detecting device 20, and issues a command to the three-way valve 9 to close the first control boat 92 before and after a certain period of time;
and a refrigerant flow control circuit A that maintains the command for a predetermined period of time, and in the heating priority operation, the first and second control boats 92 and 93 of the three-way valve 9 control the evaporator 3 and the heat exchanger 4. When the detection device 20 is in communication with the
was activated, and after a predetermined period of time had passed by the control circuit A, the first control boat 92 was closed to allow the entire amount of refrigerant from the condenser 2 to flow through the heat exchanger for a predetermined period of time.

As shown in FIG. 3, the detection device 20 uses two limit switches 20A and 20W, and the first control boat 92 of the three-way valve 9 has an opening of 100%, and the second control boat 93 has an opening of 0%. At this time, the limit switch 20W is opened, and the limit switch 20A is opened when the first control boat 92 has an opening of 0% and the second control boat 93 has an opening of 100%. 1st and 2nd
The closing operation is performed when both the control boats 92 and 93 have an opening degree of 0% or more.

The detection device 20 may use one limit switch and close when the opening of the second control boat 93 is within a certain set range, or when two limit switches 20A and 20W are used. Alternatively, the opening degree range of the first and second control boats 92 and 93 may be set, and the closing operation may be performed within this range. The limit switches 20A and 20W provided as above have their contacts connected in series as shown in FIG.
The timer relay R2, which constitutes a part of the refrigerant flow control circuit A, is connected in series. The control circuit A mainly includes a timer T1 that operates by measuring the time during which the boats 92 and 93 of the three-way valve 9 are continuously communicating with the evaporator 3 and the heat exchanger 4; Relay R fully opens the second control boat 93 of the three-way valve 9 by the operation of T1, in other words, fully closes the first control boat 92.
3. It consists of a timer T2 for energizing this relay R3 for a predetermined period of time.This control circuit A will be described in detail below.

The timer T1 is used to set the time (for example, 1 hour) during which an oil pool occurs in the air-side heat exchanger 4 and oil shortage occurs, and is used to maintain the self-holding of the timer relay R2 normally open contact and the relay R3, which will be described later. It is connected in series to the parallel circuit with the normally open contact for the timer T2 via the normally closed contact T2-1 of the timer T2, which will be described later.

The relay R3 is connected in series with the contact T1-1 that closes when the count j of the timer T1 ends, and after the limit switches 20A and 20W are closed and the tie R2 is energized and the timer T1 is activated, After one hour has elapsed, the relay R is energized, and the energization of the relay R operates the control motor of the three-way valve 9, closes the first control boat 92, and closes the second control boat 9.
The opening degree of No. 3 is 100%. Further, the timer T2 controls the excitation time of the relay R, in other words, the time for closing the first control boat 92 and setting the opening degree of the second control boat 9 to 100%.
3 are connected in parallel.

However, the relay R1 is energized and the four-way selector valve 8 is switched to the first
When switching from the solid line position in the figure to the solid line in Figure 2 to perform heating priority operation, the cooling load is small and both the first and second control boats 92 and 93 of the three-way valve 9 are connected to the evaporator as shown in Figure 2. 3 and the heat exchanger 4, the limit switches 20A and 20W are closed, and the normally open contacts are closed by the excitation of the relay R1, so that the timer relay RB is energized and the timer T1 is activated. Start.

When a certain period of time (one hour) has elapsed after the timer T1 started operating, the contact T1-1 closes, the relay R3 is energized, and the control motor of the three-way valve 9 is operated, as shown in FIG. The opening degree of the control boat 93 is set to 1
It is set as 00%.

At this time, the limit switch 20A will open, but the normally open contact will close due to the excitation of the relay R3, forming a self-holding circuit, so the limit switch 20A will open due to the operation of the three-way valve 9. Even if the ray R3 is energized, the ray R3 remains energized. Simultaneously with the excitation of the saw R3, the timer T2 starts operating, and when one fixed period of time (for example, one cycle) has elapsed after the start of this operation, the contacts T2-1 and T1-1 open, opening the self-holding circuit. Then, the relay R3 is demagnetized and the three-way valve 9 is operated to return.

Further, after this return operation, when both the first and second control boats 92, 93 of the three-way valve 9 are open, the limit switches 20A, 20W are closed, and the timer relay R2 is energized again, as described above. Repeat the action.

As described above, the first and second control boats 92 of the three-way valve 9,
93 are both open and refrigerant is flowing into the air side heat exchanger 4, even if this flow rate is small and the lubricating oil in the heat exchanger 4 may accumulate, at regular intervals, Since the entire amount of refrigerant is circulated, the accumulated oil is reliably recovered.

Although the refrigerant does not flow into the evaporator 3 during this recovery, since the cooling load is small in this case and a part of the refrigerant is detoured to the heat exchanger 4, the refrigerant does not flow into the evaporator 3 within the recovery time. Even if the cooling operation is not performed, there is little problem in cooling the air conditioner.

Moreover, during the lubricating oil recovery operation, the cooling capacity cannot be demonstrated, so when normal operation is resumed, the cold water inlet thermostat Tll3
This automatically increases the opening degree of the first control boat 92 and enables the lubricating oil recovery operation of the evaporator 3. As described above, according to the present invention, the cooling load is small and heating is prioritized, and the first and second control boats of the three-way valve communicate with the water cooling evaporator and the air-side heat exchanger to When the compressor is being operated so that refrigerant is supplied from the exchanger to the compressor, the amount of refrigerant flowing to the air-side heat exchanger is small, and oil mixed in the refrigerant may accumulate in the heat exchanger. However, after the operation has been carried out for a certain period of time, the entire amount of refrigerant is forced to flow through the heat exchanger for a certain period of time, so that the oil accumulated in the heat exchanger can be reliably recovered. , it is possible to eliminate the problem caused by oil shortage.

Furthermore, according to the present invention, there is no need for a special mechanism for recovering the oil, and the oil recovery can be accomplished with a simple configuration.
BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a refrigerant piping system diagram for cooling priority operation showing an embodiment of the device of the present invention, Fig. 2 is a refrigerant piping system diagram for heating priority operation, and Fig. 3 is a main electrical circuit. figure,
FIG. 4 is a refrigerant piping system diagram in a state in which oil recovery is controlled from the state in FIG. 2.

1...Compressor, 2...Condenser for water heating, 3...Evaporator for water cooling, 4...Air side heat exchanger, 9... Three-way valve, 20...Detection tool, 91
...Fixed boat, 92...First control boat, 93...Second control boat, Tl, T2...
...Timer, A...Refrigerant flow control circuit.

Claims (1)

[Claims] 1 Compressor 1, water heating condenser 2, water cooling evaporator 3,
Air side heat exchanger 4, one fixed port 91 and two first
and second control ports 92 and 93, the first control port 92 of the three-way valve 9 is connected to the evaporator 3, and the second control port 93 is connected to the heat exchanger 4. In the heat recovery type air conditioner, the three-way valve 9
A detection device 20 is provided which operates when the first and second control ports 92 and 93 of the evaporator 3 and the heat exchanger 4 are connected to the evaporator 3 and the heat exchanger 4, respectively. The refrigerant flow control circuit A includes a refrigerant flow control circuit A that starts timing by the operation of 20, issues a command to the three-way valve 9 to close the first control port 92 after a certain period of time, and maintains the command for a predetermined period of time. A heat recovery type air conditioner characterized by: