JPS63163725A - Air conditioner - Google Patents

Abstract

PURPOSE:To make it possible to protect against freezing during the suspension of water supply by stopping the operation of a compressor based on the output signal that is generated from means to operate and stop a compressor and judge water temperature and the output signal from water temperature difference judgement means at the outlet port and inlet port. CONSTITUTION:When the detected temperature signal that is generated from a second temperature sensor 9 provided at a water inlet section has reached a signal level that corresponds to a beforehand set temperature, an output signal for operation or stopping of operation is generated from means to operate and stop compressor and judge water temperature. A detected temperature signal that is generated from a second temperature sensor 9 and a detected temperature signal that is generated from a first temperature sensor 10 provided at a water outlet section are compared, and if the signal level difference that is corrected by a signal stored in a water temperature difference memory 13 for the water at outlet and inlet ports does not reach the signal level difference which corresponds to a beforehand set temperature difference, water temperature difference judgement means 14 for water at outlet and inlet ports issues output signal. Means 15 to operate and stop compressor operates or stops a compressor 1 on the basis of the output signal that is generated from the judgement means 11 and stops the compressor 1 on the basis of the output signal that is generated from the judgement means 14.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is capable of stopping a compressor without completely freezing the circulating water even if the circulating water stops due to a malfunction in the air conditioning circulating water system of an air conditioner. The present invention relates to an air conditioner that can prevent damage to a heat exchanger.

[Conventional technology]

Conventionally, the method of preventing freezing of the circulating water for air conditioning in a wooden air conditioner is to detect the outlet water temperature of the user side heat exchanger and completely stop the compressor if the water temperature drops below a certain level. It is commonly used, and has the form shown in Figures 4 and 5.

In the figure, 1 is a compressor, 2 is a heat exchanger on the non-use side for condensing refrigerant gas, 3 is a blower that sends air to the heat exchanger on the non-use side, 4 is a throttle device to reduce the pressure of the liquid refrigerant, and 5 is a for example,
Kochi's refrigeration cycle is comprised of a user-side heat exchanger for exchanging heat between air-conditioning circulating water circulated between an air-conditioning load device 7 such as a fan coil unit, and the refrigerant supplied from the compressor 1. ing. Further, 5a and 5b are the water inlet and water outlet of the heat exchanger 5 on the user side, 60 is a temperature switch for preventing freezing attached to the water outlet 5b, and 64 is a temperature controller attached to the water inlet 5a. A fan coil unit 7 is connected to the user-side heat exchanger 5 by an air conditioning circulating water pipe 8.

60a is a contact of the antifreeze temperature switch 60 for turning on the power to the following circuit, 61 is an operation switch, and 62 is a stop switch, which is connected in series with the self-holding relay coil 63, and is a self-holding relay. The contact 63a of 63 is connected in parallel with the operation switch 61. The other contact 63b is the contact 64a of the temperature regulator 64 and the compression@
It is connected in series with the operating electromagnetic switch coil 65 of No. 1.

Next, the operation will be explained. First, after the power is fully turned on, when the operation switch 61 is turned on, the stop switch 62 is fully connected and the self-holding relay coil 63 is energized, and the contacts 63a and 63 are turned on.
b is closed, the operation switch 61 is short-circuited by the contact 63a, and the self-holding relay coil 63 is self-held, and the contact 64af of the temperature regulator 64 is closed by the contact 63b.
As a result, the electromagnetic switch coil 65 for operating the compressor is energized, and the compressor 1 and the blower 3 start operating in conjunction with the compressor 1. The refrigerant gas discharged from the compressor 1 is cooled by the blower 3 in the non-use side heat exchanger 2 to become liquid refrigerant, the pressure is reduced by the expansion device 4, and the gas flows into the use side heat exchanger 5 from the water inlet 5a. The refrigerant exchanges heat with the circulating water for air conditioning, removes heat, evaporates, and returns to the compressor l.

In addition, the circulating water for air conditioning that has exchanged heat with the refrigerant is deprived of heat and becomes cold water, which enters the 7 uncoil unit 7 from the water outlet Iasb to cool the guiding air, and the water whose temperature has risen is returned to the user side heat exchanger 5. and is cooled.

Air conditioning is performed by repeating the above refrigerant and water cycle. Therefore, when the cooling load on the fan coil unit 7 decreases, the temperature of the air-conditioning circulating water decreases because the amount of heat extracted from the indoor air decreases, and when the temperature reaches the set temperature of the temperature controller 64, the contact point Since the electromagnetic switch coil 64a is opened, the electromagnetic switch coil 65 is deenergized, so the operation of the compressor 1 is stopped and the temperature of the air conditioning circulating water is waited for to rise. Thereafter, the inlet temperature of the main body part 5a of the user-side heat exchanger 5, in which the temperature sensing part of the temperature regulator 64 is provided, rises, and when the temperature reaches the return temperature of the temperature regulator 64, the contact 64a closes. , the electromagnetic switch coil 65 is energized, the compressor 1 starts operating again, and starts cooling.

In addition, when the flow rate of circulating water for air conditioning decreases, or when the capacity of the refrigeration cycle increases due to a drop in outside air temperature, the water inlet 5a and water outlet 5b of the user-side heat exchanger 5 are As the difference in water temperature increases, the water temperature at the water inlet 5a changes to the temperature controller 6.
Even if the temperature is higher than the set temperature in step 4, when the water temperature at the water outlet 5b approaches the freezing temperature of water (=0°C), the antifreeze temperature switch 60 is activated, and its contact 60a turns off the power to the control circuit. Since the operation electromagnetic switch coil 65 is deenergized,
The operation of the compressor 1 is stopped, and the circulating water for air conditioning is prevented from freezing.

[Problem that the invention seeks to solve]

Conventional air conditioners are configured as described above, and as mentioned above, the temperature of the outlet water of the user-side heat exchanger is used to prevent the circulating water for air conditioning from freezing. In the event that water stops flowing at all due to a pump failure, etc., the water temperature will decrease only within the user-side heat exchanger, and the water temperature at the water inlet 5a and water outlet 5b will not decrease. Ninth, freeze protection by the temperature regulator 64 and freeze prevention temperature switch 60 is not possible. In addition to the above, there are also measures to install a flow switch that detects the flow rate of circulating water for air conditioning, but there are problems such as the flow switch is expensive and the water contact part of the flow switch needs to be cleaned regularly. There are nine.

This invention was made to solve the above-mentioned problems, and provides an air conditioner that does not use expensive items such as flow switches and can provide freeze protection even when the circulating water for air conditioning is cut off. The purpose is to

[Elaborate means to solve problems]

The air conditioner according to the present invention includes a compressor that sucks in refrigerant, compresses and discharges it, a non-use side heat exchanger that exchanges heat between the refrigerant supplied from the compressor and a fluid to be heat exchanged, and a A user-side heat exchanger that exchanges heat between the supplied refrigerant and air-conditioning circulating water that is circulated between an air conditioning load device such as a fan coil unit, and detects the outlet water temperature of this user-side heat exchanger. I! which generates a specific output signal according to the outlet water temperature! a second temperature detector that detects a wide temperature at the inlet of the heat exchanger on the user side and generates an output signal according to the wide temperature at the inlet; compressor operation/stop water temperature determination means for generating an output signal for operation or stop when the generated temperature detection signal reaches a preset signal level corresponding to the next temperature; An inlet/outlet water temperature that stores a signal difference between a temperature detection signal generated from the second temperature sensor and a temperature detection signal generated from the first temperature sensor when the generated operating output signal is supplied. a compressor operating time measuring means for measuring the operating time of the compressor when an operating output signal generated from the compressor operating/stopping water temperature determining means is supplied; and the compressor operating time measuring means. If the time measured by p exceeds a certain level,
The signal level difference in the inlet/outlet water temperature temperature difference storage means is subtracted from the signal level difference between the temperature detection signal generated from the second temperature detector and the temperature detection signal generated from the I-th temperature detector. the compressor based on the output signal generated from the inlet/outlet water temperature temperature difference determining means which generates an output signal when a signal level difference corresponding to a preset temperature difference is not reached; and the compressor operation/stop water temperature determining means. and a compressor operation/stop means for operating or stopping the compressor based on the output signal generated from the inlet/outlet water temperature difference determining means.

[For production]

In this invention, when the temperature detection signal generated from the second temperature detector reaches a signal level corresponding to a preset temperature, the compressor is operated based on the output signal generated from the compressor operation/stop water temperature determining means. The operation/stopping means operates the compressor. At the same time, based on the operation output signal generated from the compressor operation/stop water temperature determination means, the inlet/outlet water temperature temperature difference storage means generates a temperature detection signal generated from the second temperature detector and a temperature detection signal generated from the first temperature detector. The level difference between the temperature detection signals is stored. On the other hand, the operating time of the compressor is measured from the time when the output signal generated from the compressor operation/stop water temperature determination means is supplied, and when a certain time has elapsed, a temperature detection signal is generated from the second temperature detector. and above lol
From the signal level difference with the temperature detection signal generated from the temperature detector c1, the nine level difference stored in the inlet/outlet water temperature temperature difference storage means is corrected, and the ratio signal level difference corresponds to the preset temperature difference. When the signal level difference is not reached, based on the output signal generated from the inlet and outlet water temperature difference determination means,
The compressor operation/stop means acts to stop the compressor.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of an air conditioner showing an embodiment of the present invention. The refrigeration cycle side of this embodiment is the same as that of the conventional embodiment, but as is clear from the figure, the control part is configured as follows. 9 is the user side heat exchanger 5
A second temperature detector, IO, is provided at the water outlet section 5b of the user-side heat exchanger 5, and is provided at the water inlet section 5aiC to detect the inlet wide temperature and generate an output signal according to the inlet wide temperature. This is a first temperature detector that detects the temperature of the outlet water and generates an output signal corresponding to the temperature of the outlet water.

Reference numeral 11 denotes compressor operation/stop water temperature determination means, which outputs an output signal for operation or stop when the temperature detection signal generated from the second temperature detector 9 reaches a signal level corresponding to a preset temperature t. It is something that occurs. Reference numeral 12 indicates a compressor operating time which starts measuring the operating time of the compressor 1 when the operating output signal generated from the compressor operating/stopping water temperature determining means 11 is supplied, and generates an output signal when a certain period of time is reached. It is a means of measurement. 13, when the operating output signal generated from the compressor operation/stop water temperature determining means 11 is supplied, the first
Inlet/outlet water temperature temperature difference storage means for storing the level difference between the temperature detection signal generated from the temperature detector 10 and the temperature detection signal generated from the second temperature detector 9; Temperature detection signal and first temperature detector 1
The ratio signal level difference is compared with the temperature detection signal generated from 0 and corrected by the signal stored in the inlet/outlet water temperature temperature difference storage means 13, and the ratio signal level difference reaches a signal level difference corresponding to a preset temperature difference. This is an inlet/outlet water temperature difference determining means that generates an output signal when the output signal is not detected. Reference numeral 15 denotes a compressor for fully operating or stopping the compressor 1 based on the output signal generated from the compressor operation/stop water temperature determining means 11, and stopping the compressor 1 based on the output signal generated from the inlet and outlet water temperature temperature difference determining means 14. It is a means for starting and stopping the machine.

FIG. 2 is a circuit diagram showing electrical connections of the air conditioner shown in FIG. 1. In the figure, 18 is a microcomputer in the control device 17, and a CPU (central processing unit) 19. memory 2
0. Input circuit 21. The output circuit 22 is shown. 23.
24 is a voltage dividing resistor connected in series with each temperature sensor 9 and 10, 2
Reference numeral 5 denotes an A/D converter to which the detection outputs of the temperature detectors 9 and 10 are input, converting the analog signal into a digital signal, and the output thereof is given to the input circuit 21. 27 is a resistor connected in series with the operation switch 29; 28 is a resistor connected in series with the protection device 30 of the compressor 1; status signals of the operation switch 29 and the protection device 30 are also applied to the input circuit 21. Compressor operation/
The stop means 15 includes an auxiliary relay coil 31 that outputs a signal to an electromagnetic switch for a compressor (not shown), its contacts 31a, and its terminals 32t, and the collector is connected to the power supply +V via the auxiliary relay coil 31. , a grounded emitter transistor 330 is connected to the output circuit 22 via a resistor 34.

Next, the operation of the above embodiment will be explained with reference to FIG. Figure 3 shows the memory 201C of the microcomputer 18.
9 is a flowchart showing a stored program of the air conditioner according to the present invention.

First, when the operation switch 29 is closed, the ON signal is inputted to the input circuit 21, step 36 shown in FIG. 3 is executed, and then step 37 is started to determine whether or not the water temperature is at a temperature that allows operation to start. This judgment is made when the operation switch 29 is
This is done only when the operation is started by switching from "open" to "open", and when the second temperature detector 9 detects the temperature, the compressor 1
f. When the stopping temperature is set to, for example, 10° C., rYEsJ is determined when the inlet wide temperature is higher than the set temperature by, for example, 3° C. or more. The temperature of the air-conditioning circulating water detected in this judgment is detected by the second temperature detector 9 using the inlet wide temperature of the user-side heat exchanger 5, and is digitized by the converter 25 and sent to the input circuit 2.
1 is input. Next, if the determination is rNOJ based on the result of the determination, the determination is made again, and the determination is repeated until the determination becomes rYESJK. rYEsJ
If so, proceed to step 38, where an output is output from the output circuit 22, turning on the transistor 33, energizing the auxiliary relay coil 31, closing the contact 31a, and outputting a signal from the terminal 32 to an electromagnetic switch for the compressor (not shown). Then, the compressor 1, the feeder S connected to the compressor 1, and the rock 3 start operating, and the outlet water temperature starts to decrease. In the next step 39, the microcomputer simultaneously measures the compressor operating time while the compressor 1 is running.
18, and the time is accumulated in the memory 20. In step 40, the water temperature Ti and the water temperature Ti and The temperature difference Td of To is calculated and stored in the memory 20 of the microcomputer-18. next,
In step 41, it is determined whether or not there is any abnormality in the compression mode l, that is, whether or not the protection device i30 is not operating.If it is determined that there is an abnormality, the process proceeds to step 51, where the output There is no output from circuit 22, auxiliary relay coil 31 is deenergized, and its contacts 31
a opens, and the compressor 1 and blower 3 stop.

The presence or absence of an abnormality is determined when the signal from the protection device 30 is input to the input circuit 2.
1 and executed on the CPUI 9. After determining that there is no abnormality in step 41, step 42
Then, it is determined whether or not there is a risk of freezing of the circulating water for air conditioning, and the detected friend water temperature To of the water outlet portion 5b of the user-side heat exchanger 5 satisfies To > Tf with respect to the freezing temperature of water Tf. It is determined whether or not the compressor 1 is
will be stopped.

After it is determined in step 42 that there is no risk of freezing, it is then determined in step 43 whether or not the compressor operating time is being measured.If not, the process advances to step 47 and one step is performed. If so, the process proceeds to step 44, where the measurement is performed and 9 hours'rrnC is set in advance, and T'ff1 is set for 9 hours Tms (for example, 2 minutes).
It is determined whether c≧Tms or not, 'I'mc≧'I'ms
If not, proceed to step 47. In step 47, a compressor operation/stop water temperature determination operation is performed, and it is determined whether or not the detected nine inlet water temperature T1 and the set water temperature Ts are Ti≦Ts.If Ti≦Ts, the process proceeds to Step 41. Go back and repeat steps 41-47.

For example, two minutes after the start of measuring the compression operation time, if it is determined in step 44 that Tmc≧Tms, the process proceeds to step 45, where an operation is performed to determine the difference in inlet and outlet water temperatures.
Using the inlet water temperature Ti detected by the second temperature detector 9, the outlet water temperature 5 detected by the first temperature detector 6, and the temperature difference Tcl stored in the memory 20, 2 <
It is determined whether or not l Ti -To-T (11).Tr is determined by knowing the temperature difference between the inlet water temperature Ti and the outlet water temperature TO, and if the temperature difference is more than a certain value, the compressor engineer During operation, the circulating water for air conditioning is cooled and the water flows through the heat exchanger 5 on the user side, so that it can be determined that there is a temperature difference. Detection errors of the temperature detector 10 and the second temperature detector 9 can be corrected.

If the temperature difference is extremely small, the water in the heat exchanger 5 on the user side is cooled by the operation of the compressor 1, but the water is not flowing due to a failure of the pump in the circulating water piping for air conditioning, etc. It can be determined that there is no difference in temperature between the inlet section 5a and the water outlet section 5b.

If 2 < I Ti -To-Td I is not satisfied, it is determined that the air-conditioning circulating water has been cut off, and the process proceeds to step 51, where the compressor 1 is stopped in the same manner as described above.

If 2<l Ti -To-'i l, in step 46, the measurement of the operating time of the compressor 1 is completely completed, and the accumulated time in the memory 20 is reset.

Next, the process proceeds to step 47, where it is determined whether Ti≦TS as described above. If the inlet water temperature Ti is set and is lower than the next water temperature Ts, the process proceeds to step 48, where the compressor 1 is stopped, and then In step 49, the system waits for the temperature of the air conditioning circulating water to rise.

Next, if it is determined in step 50 that Ti)Ts+3 is not established, the process returns to step 49 and the above operation is repeated. In step 50, after the compressor 1 is stopped, the inlet water temperature Ti increases due to the temperature rise of the circulating water for air conditioning, and the inlet water temperature T
If i is set in advance and the original temperature Ts rises by, for example, 3°C or more, then Ti>TS+3, and it is determined that the compressor 1 is in operation, and the process returns to step 38, where the compressor 1 and the blower 3
is operated, and from then on, the operation and
There are repeated stops.

In addition, in the above embodiment, the case of an air-cooled cooling-only air conditioner is described, but the same applies to a water-cooled type.
Friend, a heat pump type air conditioner also has the same effect as the above embodiment.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a compressor that takes in refrigerant, compresses and discharges it, a non-use side heat exchanger that exchanges heat between the refrigerant supplied from the compressor and a fluid to be heat exchanged, and a A user-side heat exchanger exchanges total heat with the air-conditioning circulating water that circulates between the refrigerant supplied by the fan coil unit and an air-conditioning load device such as a fan coil unit, and the outlet water temperature of this user-side heat exchanger is detected. , a first temperature detector that generates an output signal according to the outlet water temperature, and a second temperature detector that detects the inlet water concentration of the user-side heat exchanger and generates an output signal according to the inlet water concentration. A temperature sensor and a compressor operation/stop water temperature determination system that generates an output signal for operation or stop when the temperature detection signal generated from the temperature sensor of Type 2 reaches a signal level corresponding to a preset temperature. and a temperature detection signal generated from the first temperature detector and a temperature detection signal generated from the second temperature detector when the operation output signal generated from the compressor operation/stop water temperature determination means is supplied. an inlet/outlet water temperature difference storage means for storing a signal level difference between the
When the operation output signal generated from the pressure a# machine operation/stop water temperature determination means is supplied, the compressor? A compressor operating time measuring means for measuring the operating time, and when the time t measured by the compressor operating time measuring means exceeds a certain value, the temperature detection signal generated from the λ-th temperature sensor and the first The level difference in the inlet/outlet water temperature temperature difference storage means is subtracted from the signal level difference between the temperature detection signal generated from the temperature sensor and when the ratio value does not reach the preset signal level difference corresponding to the next temperature difference, the output signal is The compressor is fully operated or stopped based on the output signal generated from the compressor operation/stop water temperature determination means and the output signal generated from the inlet and outlet water temperature difference determination means. Since the air conditioner is constructed by providing a compressor operation/stop means for stopping the compressor, even if the circulating water for air conditioning stops flowing due to, for example, a malfunction of the circulation pump or a blockage in the piping, the system can be used. This eliminates the risk of freezing in the heat exchanger on the user side.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an air conditioner showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing electrical connections of the air conditioner shown in FIG. 1, and FIG. 3 is a flow chart showing its operation. FIG. 4 is a block diagram of a conventional air conditioner, and FIG. 5 is an electrical circuit diagram of its control section. 1... Compressor, 2... Non-use side heat exchanger, 5...
Utilization side heat exchanger, 7... Air conditioning load device such as fan coil unit, 9... Second temperature detector, 10... First temperature detector, 11... Compressor operation/stop Water temperature determination means, 12... Compressor operating time measurement means, 13...
Inlet/outlet water temperature difference storage means, 14... Inlet/outlet water temperature difference determination means, 15... Compressor operation/stopping means. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A compressor that sucks in refrigerant, compresses and discharges it, a non-use side heat exchanger that exchanges heat between the refrigerant supplied by the compressor and the fluid to be heat exchanged, and a heat exchanger that exchanges heat between the refrigerant supplied by the compressor and the air conditioning load device a user-side heat exchanger that exchanges heat with air conditioning circulating water; a first temperature detector that detects the outlet water temperature of the user-side heat exchanger and generates an output signal according to the outlet water temperature; , detect the inlet water temperature of the above-mentioned user-side heat exchanger,
a second temperature sensor that generates an output signal according to the inlet water temperature; when the temperature detection signal generated from the second temperature sensor reaches a signal level corresponding to a preset temperature, the compression A compressor operation/stop water temperature determination means that generates an output signal for operating or stopping the compressor, and when an operation output signal generated from the compressor operation/stop water temperature determination means is supplied, a signal is generated from the second temperature detector. an inlet/outlet water temperature temperature difference storage means for storing a signal level difference between the temperature detection signal generated by the temperature detection signal and the temperature detection signal generated from the first temperature detector; and an operation output signal generated from the compressor operation/stop water temperature determination means. a compressor operating time measuring means that starts measuring the operating time of the compressor when temperature detection signal and the first
When the value obtained by subtracting the signal level difference in the inlet/outlet water temperature temperature difference storage means from the signal level difference with the temperature detection signal generated from the temperature detector does not reach a signal level difference corresponding to a preset temperature difference, An output signal is generated from the inlet/outlet water temperature difference determining means for operating or stopping the compressor based on the output signal generated from the compressor operation/stop water temperature determining means and the inlet/outlet water temperature difference determining means for generating an output signal. An air conditioner comprising a compressor operation/stop means for stopping the compressor based on the above.