JPH031745Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the improvement of air conditioning equipment that normally controls air conditioning conditions to be stable under certain conditions, such as in environmental test chambers. The exhausted waste heat energy is recovered in the hot water heat exchanger and effectively used as an auxiliary heat source for heating, and water in the hot water heat exchanger system is eliminated during cooling operation, especially under low temperature air conditioning conditions. One of the purposes is to prevent the harmful effects of freezing.

BACKGROUND ART Conventionally, air conditioners in environmental test chambers and the like are generally configured with a cooling function of a refrigeration cycle that is operated regardless of air conditioning conditions, a warming heater that controls air conditioning conditions, and a humidifier. In such a configuration, when controlling the air conditioning to raise the temperature to the desired condition or for heating, the refrigeration cycle for cooling is operated at a constant rate, the heater input is increased, and the heating capacity of the heater exceeds the cooling capacity. The predetermined air conditioning conditions were set by controlling the air conditioner. On the other hand, the hot water discharged from the water-cooled condenser is either directly discharged to the outside or is reused in a cooling tower, which is not effective in terms of energy saving. In addition, when a hot water heat exchanger is used for waste heat recovery, there is a drawback that during cooling operation, the water in the hot water heat exchanger system freezes under low temperature air conditioning conditions and destroys the hot water heat exchanger. had.

In view of the above-mentioned conventional points, the present invention was developed in an air conditioner that controls the air conditioning of an environmental test room, etc., when controlling the air conditioning by heating operation, the waste hot water of the water-cooled condenser is used for heating. In addition to being effectively used as a hot water heater for air conditioning control, the cooling capacity is reduced, and during cooling operation, water in the hot water heat exchanger system is removed when low-temperature air conditioning conditions are reached, preventing harmful effects caused by freezing. The present invention provides an air conditioner.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings showing an embodiment of the present invention.

In FIG. 1, 1 is a compressor, 2 is a water-cooled condenser, 3 is an expansion valve, 4 is an evaporator, and 5 is an accumulator, which are sequentially connected in a ring to form a well-known refrigeration cycle. A refrigerant switching valve 6 is provided between the expansion valve 3 and the evaporator 4, and one end thereof constitutes a bypass circuit 6a connected to a part of the evaporator 4. In addition, the inlet water pipe 2a of the water-cooled condenser 2 includes a first electromagnetic on-off valve 7 for a large flow rate of cooling water, a second electromagnetic on-off valve 8 for a medium flow rate, and a third electromagnetic on-off valve for a small flow rate. 9 are connected in parallel and manually switched according to the size of the heating load. Reference numeral 10 denotes a cooling water electromagnetic on-off valve installed in the outlet side water pipe 2b of the water-cooled condenser 2, which operates in parallel with the cooling water electromagnetic on-off valve 10 during heating to recover waste heat and use it as an auxiliary heater. Solenoid open/close valve for hot water 1
1 and a hot water heat exchanger 12 are connected in series. These constitute a bypass circuit 2c.
Further, the evaporator 4 and the hot water heat exchanger 12 are provided in the same ventilation circuit. Reference numeral 13 denotes a low-pressure air pipe, which opens the low-pressure air electromagnetic on-off valve 14 when the intake air temperature drops to a predetermined temperature during cooling operation, and discharges water from the hot water heat exchanger system 12 to prevent it from freezing. It is something. Reference numeral 15 denotes a drainage switching valve, which is interlocked with the low-pressure air electromagnetic on-off valve 14. A check valve 16 prevents the discharged water from flowing into the heat exchanger system again.

Further, the ventilation circuit includes a built-in heater 17 and a humidifier 18 that can be air-conditioned according to the load.
The fan motor 19 and the fan 20 constitute an air conditioner 21.

Next, the electric circuit will be explained with reference to FIG. Here, the same numbers as those in FIG. 1 are given the same numbers, and the description thereof will be omitted.

In the figure, 22a is a power supply, 22 is a source switch, and 23 is a heating/cooling switch, which switches to the X side for cooling and to the Y side for heating depending on the air conditioning load conditions. 24 is an electromagnetic coil that is energized during cooling operation;
The contact 25 is opened and closed. 26 is a main switch that changes the flow rate of cooling water according to the load during heating, and includes a switch 27 for the first electromagnetic on-off valve 7 for large flow and a switch 29 for the third electromagnetic on-off valve 9 for small flow. The switch is configured to form a closed circuit. 30 is a thermostat for the air conditioning control heater 17, which opens and closes depending on the load. 31 is interlocked with the cooling/heating changeover switch 23, during heating operation,
It closes and directs the refrigerant to the bypass circuit, reducing the cooling capacity. 32 is an electromagnetic coil that is energized during heating operation, closes the contact 33, and closes the hot water electromagnetic on-off valve 11.
to open. 34 is a drainage thermostat which operates a first timer 35 when the intake air temperature of the air conditioner 21 falls below a predetermined temperature, and for a predetermined period of time (approximately 5 seconds) contacts 35a of the first timer 35,
35b is closed, the low-pressure air electromagnetic on-off valve 14 is opened, and the discharge water electromagnetic on-off valve 15 is switched to the discharge side. This allows water in the hot water heat exchanger system to be discharged to the outside.

Next, the operation of the air conditioner with the above configuration will be described as cooling operation, heating capacity in heating operation as low capacity,
The explanation will be given with reference to a timing chart showing the operating status of the solenoid valve that opens and closes depending on the load status shown in Fig. 3, divided into medium capacity and large capacity. First, when performing cooling operation, the power switch 22 is turned on, and the cooling/heating changeover switch 23 is turned on to the cooling X-side contact, and the electromagnetic coil 24 closes the contact 25. As a result, the first electromagnetic on-off valve 7 operates to perform the cooling operation. When a predetermined air conditioning condition is reached, the thermostat 30 of the heater 17 is activated, and the set air conditioning condition is ensured by input control of the heater 17. Furthermore, when the temperature of the intake air of the air conditioner 21 falls below a predetermined temperature, the low-pressure air electromagnetic on-off valve 14 is opened, and the water in the hot water heat exchanger 12 system is discharged by low-pressure air for a certain period of time. This can prevent damage to the piping system and poor circulation due to freezing.

Next, in the case of "low" capacity during heating operation, the cooling/heating changeover switch 23 may be turned on to the Y side contact for heating, and the first electromagnetic on-off valve switch 26 for large flow rate may be closed.

On the other hand, since the cooling/heating changeover switch 23 is switched to the Y side contact, the cooling water solenoid valve 10 is closed and at the same time the hot water solenoid valve 11 is opened, and the cooling water is supplied from the outlet of the water-cooled condenser 2 to the hot water solenoid valve 11. Bypass circuit 2 passing through valve 11 and through hot water heat exchanger 12
c, and at the same time, the refrigerant switching valve 6 causes the refrigerant to flow in the direction passing through the refrigerant bypass circuit 6a. Therefore, the refrigerant passes through a portion of the evaporator 4, undergoes heat exchange, and is circulated to the accumulator 5 and the compressor 1.
In this way, the heat source exhausted from the water-cooled condenser 2 can be effectively used as an auxiliary heater for heating, and since the refrigerant bypass circuit 6a is provided to reduce the cooling capacity, more effective heating can be performed.

In addition, when the capacity is "medium" during heating operation, the cooling/heating changeover switch 23 is similarly turned on to the Y side for heating, and the second electromagnetic opening/closing switch 28 for medium flow is turned on.
Just close it.

In this case, since the amount of cooling water is reduced compared to the case of "small" heating capacity, the outlet temperature of the cooling water from the water-cooled condenser 2 becomes higher, increasing the heating capacity of the hot water heat exchanger 12, and increasing the pressure The increase in the compression ratio accompanying the rise in , reduces the cooling capacity, and the heating capacity becomes larger than when the heating capacity is "small".

Next, in the case of "high" capacity during heating operation, similarly, turn on the cooling/heating changeover switch 23 to the Y side for heating, and turn on the third electromagnetic on-off valve switch 2 for small flow.
Just close 9. Therefore, similar to the above,
The heating capacity is further increased compared to the case of "medium" heating capacity.

In this embodiment, a plurality of electromagnetic on-off valves 7, 8, and 9, which are flow rate variable means, are provided in the inlet water pipe 2a of the water-cooled condenser 2, and a valve device that can continuously control the flow rate is incorporated. However, it goes without saying that heating capacity can be effectively controlled.

As is clear from the above embodiments, the air conditioner of the present invention has a refrigerant switching valve between the expansion valve and the evaporator of a refrigeration cycle circuit equipped with a water-cooled condenser, and a part of the evaporator. while configuring a refrigerant bypass circuit connected to the water-cooled condenser, a valve device having a flow rate variable means is provided in the inlet side waterway piping of the water-cooled condenser, and a cooling water electromagnetic on-off valve is provided in the outlet side waterway piping,
A bypass circuit consisting of a hot water solenoid on-off valve and a hot water heat exchanger is provided in parallel with the cooling water solenoid on-off valve, and the evaporator and the hot water heat exchanger are provided in the same ventilation circuit. A low-pressure air pipe with a low-pressure air solenoid on-off valve is connected to the inlet water pipe between the exchanger and the hot water solenoid on-off valve,
In addition, a discharge water switching valve is installed in the hot water piping on the outlet side, and when the intake air temperature falls below a predetermined temperature during cooling operation, the low-pressure air solenoid on-off valve and the discharge water switching valve are opened, and the hot water switching valve is opened. This system is designed to discharge residual water from the heat exchanger system, which prevents damage such as damage to piping and poor circulation due to freezing in the hot water heat exchanger system, especially under low-temperature air conditioning conditions, and also prevents problems such as poor circulation. At this time, the refrigerant that exits the expansion valve flows into the bypass circuit, reducing the cooling capacity of the evaporator.On the other hand, the waste hot water that exits the water-cooled condenser can be effectively used as a heat source for heating, and under load conditions. It has various advantages, such as being able to control the heating capacity depending on the situation.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an air conditioner showing an embodiment of the present invention, Fig. 2 is an electric circuit diagram of the air conditioner, and Fig. 3 is a valve valve during cooling operation and heating operation in the air conditioner. It is a timing chart diagram showing the opening and closing of etc. 1...Compressor, 2...Water-cooled condenser, 2a...
Inlet side waterway piping, 2b...Outlet side waterway piping, 2c
... Bypass circuit, 3 ... Expansion valve, 4 ... Evaporator, 5 ... Accumulator, 6 ... Refrigerant switching valve, 6a ... Bypass circuit, 10 ... Solenoid on-off valve for cooling water, 11 ... Hot water Solenoid on/off valve for 12...
Hot water heat exchanger, 13...Low pressure air piping, 14
...Solenoid on-off valve for low pressure air.

Claims (1)

[Scope of utility model registration request] A compressor, a water-cooled condenser, an expansion valve, an evaporator, and an accumulator are sequentially connected by refrigerant piping, and a refrigerant switching valve is provided between the expansion valve and the evaporator, and a refrigerant bypass is connected in the middle of the evaporator. The circuit is configured such that a variable flow rate valve device is provided in the inlet side waterway piping of the water-cooled condenser, and a cooling water solenoid on-off valve is provided on the outlet side waterway piping, and a heating valve is provided in parallel with the cooling water solenoid on-off valve. A hot water solenoid on-off valve that operates when the hot water heat exchanger is activated, a bypass circuit in which the hot water heat exchanger is connected in series, and the evaporator and the hot water heat exchanger are provided in the same ventilation path, and the hot water heat exchanger inlet and the hot water solenoid on-off valve are provided. A low-pressure air pipe with a solenoid on-off valve for low-pressure air is connected to the hot water pipe between the hot water pipes, and a discharge water switching valve is provided to the hot water pipe between the hot water heat exchanger outlet and the writing side water pipe. , when the temperature detection means detects that the intake air temperature has become below a predetermined temperature, the low-pressure air electromagnetic on-off valve is opened;
An air conditioner that removes residual water from the hot water heat exchanger by switching the discharge water switching valve.