JPS63135743A - Air conditioning apparatus - Google Patents

Abstract

PURPOSE:To eliminate a risk of freezing occurring in a heat exchanger on the utilization side,by a method wherein a means stopping a compressor without freezing circulating water even when circulating water is stopped caused by a trouble of a circulating water system for air conditioning is situated on an air conditioning apparatus. CONSTITUTION:In a title air conditioning apparatus when a temperature detecting signal generated from a temperature detector 9 for detecting the temperature of a water inlet 5a of a heat exchange 5 on the utilization side is adjusted to a signal level equivalent to a set temperature, on the basis of an output signal from a compressor running stop water temperature deciding means 11, a compressor running stop means 13 runs a compressor 1. Commencing in a time when an output from the water temperature deciding means 11 is fed to a compressor running time measuring means 12, the running time of the compressor 1 is measured. After elapse of a specified time, when a signal level difference between a detecting signal from a temperature detector 10 of a water outlet part 5b and a detecting signal from a temperature detector 9 is not increased to a signal level equivalent to a set temperature on the basis of output signal from a water outlet water temperature difference deciding means 14, the compressor running stop means 13 stops running of the compressor 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention provides a method for stopping a compressor without 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 circulating water for air conditioning in hydraulic air conditioners is to detect the outlet water temperature of the user side heat exchanger and stop the compressor if the water temperature drops below a certain level. A commonly used case was as shown in Figs. 4 and 5.

Of these Figures 4 and 5, first in Figure 5, 1 is a compressor, 2 is a non-use side heat exchanger for condensing refrigerant gas, and 3 is a non-use side heat exchanger 3 for supplying air. 4 is a throttling device for reducing the pressure of the liquid refrigerant; 5 is air conditioning circulating water that is circulated between an air conditioning load device 7 (hereinafter referred to as a fan coil unit) such as a fan coil unit; and the compressor 1. The user-side heat exchanger for exchanging heat with the refrigerant supplied by the refrigerant constitutes a well-known refrigeration cycle.

A fan coil unit 7 is connected between the water inlet portion 5a and the water outlet portion 5b of the user-side heat exchanger 5 by an air conditioning circulating water pipe 8, and a temperature regulator 64 is attached to the water inlet portion 5a. A temperature switch 60 for preventing freezing is attached to the water outlet portion 5b.

Next, the control circuit shown in FIG. 5 will be explained. A contact 60a (normally closed) of the antifreeze temperature switch 60 is connected between both poles of the power supply.
A series circuit of the operation switch 61, stop switch 62, and self-holding relay coil 63 is connected.

A self-holding relay coil 6 is connected in parallel to the operation switch 61.
No. 3 contact 63a (normally open) is connected.

Further, in parallel to the series circuit of the operation switch 61, the stop switch 62, and the self-holding relay coil 63, a contact 63b (normally open) of the self-holding relay coil 63 and a contact 64a (normally closed) of the temperature regulator 64 are connected. A series circuit with the operating electromagnetic switch coil 65 is connected.

Next, the operation will be explained. First, after turning on the power, when the operation switch 61 is turned on, the self-holding relay coil 63 is energized through the stop switch 62, and its contacts 63a and 6
3b is closed, the operation switch 61 is short-circuited by the contact 63a, and the self-holding relay coil 63 is self-holding.
Also, depending on the contact 63b, the contact 64a of the temperature regulator 64
Through this, 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 transferred to the non-use side heat exchanger 2.
The refrigerant is cooled by the blower 3, becomes a liquid refrigerant, is depressurized by the expansion device 4, and exchanges heat with the air-conditioning circulating water flowing in from the water inlet 5a in the user-side heat exchanger 5, and the refrigerant absorbs heat and evaporates. , return to compressor 1.

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 fan fill unit 7 from the water outlet 5b to cool the indoor air, and the water whose temperature has increased is returned to the user side heat exchanger. 5 and is cooled.

Repeat the above refrigerant and water cycle to perform air control.

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 64a closes. Since it is open, the electromagnetic switch coil 65 is deenergized, and the operation of the compressor 1 is stopped to wait for the temperature of the air conditioning circulating water to rise.

Thereafter, the inlet temperature of the water inlet section 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
is closed, the electromagnetic switch coil 65 is energized, and the compressor 1 starts operating again to start cooling.

In addition, when the flow rate of the circulating water for air conditioning decreases or when the capacity of the refrigeration vehicle increases due to a drop in outside air temperature, the difference in water temperature between the water inlet section 5a and the water outlet section 5b of the user-side heat exchanger 5 may increase. Even if the water temperature at the water inlet 5a is equal to or higher than the set temperature of the tube 64, if the water temperature at the water outlet 5b approaches the freezing temperature of water (20°C), the freeze prevention temperature switch will close. 60 is activated, its contact 60a cuts off the power to the control circuit, and the power 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]

The conventional air conditioner has a heat exchanger 5 on the user side as described above.
Since the circulating water for air conditioning is prevented from freezing depending on the outlet water temperature of The rounding occurs only within the exchanger 5, and the water temperature at the water inlet section 5a and water outlet section 5b does not decrease, and freeze protection by the temperature regulator 64 and antifreeze temperature switch 60 cannot be performed.

In addition to the above method, there is also a method of installing a flow switch that detects the flow rate of circulating water for air conditioning, but the flow switch is expensive, and it is necessary to regularly clean the water contact part of the 70-switch. There were problems such as.

This invention was made to solve this problem, and does not use expensive items such as flow switches.
The object of the present invention is to obtain an air conditioner that can provide freeze protection even when the circulating water for air conditioning is temporarily cut off.

[Means for solving problems]

The air conditioner according to the present invention starts or stops when the temperature detection signal generated from the temperature detector that detects the concentration of water at the inlet of the heat exchanger on the user side reaches a signal level corresponding to a preset temperature. compressor operation stop water temperature determining means for generating an output signal; and compressor operation time measuring means for measuring the operating time of the compressor when the operation output signal generated from the compressor operation stop water temperature determining means is supplied. When the time measured by the compressor operating time measurement means exceeds a certain level, a temperature detection signal generated from a first temperature detector that detects the outlet water temperature of the user heat exchanger and a second temperature detection signal are generated.
an inlet/outlet water temperature difference determining means for generating an output signal when the signal level difference with the temperature detection signal generated from the temperature sensor does not reach a signal level difference corresponding to a preset temperature difference; Compressor operation stop means is provided for operating or stopping the compressor based on an output signal generated from the water temperature determination means and for stopping the compressor based on an output signal generated from the inlet and outlet water temperature difference determination means.

[For production]

In this invention, when the temperature detection signal generated from the temperature sensor of gg2 reaches a signal level corresponding to a preset temperature, the compressor operation is stopped based on the output signal generated from the compressor operation stop water temperature determination means. The means operates the compressor, and measures the operating time of the compressor from the time when the output signal generated from the compressor operation stop water temperature determining means is supplied to the compressor operating time measuring means, and when a certain period of time has elapsed, the first When the signal level difference between the temperature detection signal generated from the first temperature sensor and the temperature detection signal generated from the second temperature sensor does not reach a signal level difference corresponding to a preset temperature difference, the inlet and outlet water temperature temperature difference Based on the output signal generated from the determination means, the compressor operation stop means acts to stop the compressor.

〔Example〕

Embodiments of the air conditioner of the present invention will be described below based on 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.

Reference numeral 9 denotes a second temperature detector provided at the water inlet portion 5a of the user-side heat exchanger 5 to detect the inlet water concentration and generate an output signal according to the inlet water concentration; 1o is the user-side heat exchanger This is a first temperature detector provided at the water outlet section 5b of No. 5 to detect the outlet water temperature and generate an output signal according to the outlet water temperature.

Compressor operation stop water temperature determination means 11 is a second temperature detector 9
When the temperature detection signal generated from the temperature detection signal reaches a signal level corresponding to a preset temperature, an operation or stop output signal is generated.

When the operation output signal generated from the compression operation stop water temperature determination means 11 is supplied, the compressor operation time measurement means 12
starts measuring the operating time of the compressor 1, and generates an output signal when a certain period of time has elapsed.

The entrance/exit wide temperature determination means 14 determines that the signal level difference between the temperature detection signal generated from the first temperature detector 10 and the temperature detection signal generated from the second temperature detector 9 corresponds to a preset temperature difference. When the signal level difference is not reached, an output signal is generated.

The compressor operation stop means 13 operates or stops the compressor 1 based on the output signal generated from the compressor operation stop water temperature determination means 11.

FIG. 2 is a circuit diagram showing electrical connections of the air conditioner shown in FIG. 1. In the figure, 18 is a microcomputer within the control device 17, and includes a CPU 19, a memory 20, an input circuit 21, and an output circuit 22t. 23.24 is a resistor in series with each temperature detector 9, 10, 25 is each temperature detector 9
.

27 is a resistor in series with the operation switch 29, 28 is the compressor 1
is a resistor in series with the protection device 30, and the operation switch 29
A status signal of the protection device 30 is also applied to the input circuit 21 .

The compressor operation stop means 13 includes an auxiliary relay 31 and contacts 31 that output a signal to a compressor electromagnetic switch (shown in the figure).
a, and a terminal 32, the transistor 330 pace is connected to the output circuit 22 via a resistor 34 and its emitter is grounded; the rector is connected via an auxiliary relay 31 to the power supply.

Next, the operation of the above embodiment will be explained with reference to FIG. FIG. 3 is a flowchart showing the program of the air conditioner of the present invention stored in the memory 20 of the microcomputer 18.

First, when the operation switch 29 is closed, the ON signal is input to the input circuit 21, step 36 shown in FIG. 3 is executed, and next step 37, determination of whether the water temperature is high enough to start operation is started. .

This determination is made only when the operation switch 29 is changed from "open" to "closed" to start operation, and the second temperature detector 9 detects the temperature at which the compressor 1 is stopped. If the temperature is set to 10℃, and the inlet water temperature is higher than this set temperature, for example by 3℃ or more,
It is used to determine rYEsJ.

The temperature of the air-conditioning circulating water detected in this determination is detected by the second temperature detector 9 using the inlet water temperature of the user-side heat exchanger 5, and is desolated by the A/D converter 25 and input to the input circuit. 21.

Next, based on the determined result, if the determination is "NO", the determination is performed again, and the determination is repeated until the determination becomes rYEsJ.

If the determination is rYEsJ, the process proceeds to step 38, where an output is output from the output circuit 22, turning on the transistor 33, energizing the auxiliary relay 31, closing its contact 31a, and connecting the compressor electromagnetic switch (not shown) from the terminal 32. The compressor 1 and the blower 3 connected to the compressor 1 start operating, and the outlet water temperature starts to decrease.

In step 39, the compressor 1 is operated simultaneously.

Measurement of compressor operating time is performed by microcomputer 18C.
It is started in the PU 19 and the time is accumulated in the memory 20.

Next, in step 40, it is determined whether or not there is any abnormality in the compressor 1, and if it is determined that there is an abnormality,
Proceeding to step 50, the output from the output circuit 22 disappears, the auxiliary relay 31 is deenergized, its contact 31a is opened, and the compressor 1 and blower 3 are stopped.

A signal from the protection device 3o is input to the input circuit 21, and the CPU 19 determines whether or not there is an abnormality in the compressor 1.

Next, in step 41, it is determined whether or not there is a risk of freezing of the air circulation water, and the detected water temperature To of the water outlet portion 5b of the user-side heat exchanger 5 is equal to the freezing temperature Tf of the water.
On the other hand, it is determined whether To>Tf, and if To>Tf, there is a risk of freezing, so the process proceeds to step 50, and the compressor 1 is stopped as in step 40 above.

Next, in step 42, it is determined whether or not the compressor operating time is being measured by the compressor operating time measuring means 12. If it is determined that the compressor operating time is being measured, the process proceeds to step 43, where the measured time is preset time T
ms (for example, 2 minutes), it is determined whether T'mc≧T'ms, and if Tm C≧Tm3, the process proceeds to step 46, where the compressor operation/stop water temperature determining means 11 determines the compressor operation/stop water temperature. A determination operation is performed, and the detected inlet water temperature Ti and the set water flow T8 are determined to be Ti≦T8.
If Ti≦T8 is not satisfied, the process returns to step 40 and steps 40 to 46 are repeated.

After 2 minutes, in step 43 % 'I"me≧T'r
If it is ns, the process proceeds to step 44, where the inlet/outlet water temperature difference determination operation of the inlet/outlet water temperature difference determining means 14 is performed.
The detected inlet water temperature Ti and outlet water temperature T.

It is determined whether 2<ITi-Tol.

By knowing the temperature difference between the inlet water temperature Ti and the outlet water temperature To, if the temperature difference is above a certain level, the air conditioning circulating water is cooled by the operation of the compressor 1 and the inside of the user side heat exchanger 5 is cooled. It can be determined that there is a temperature difference due to the flow of water.

If the temperature difference is extremely small, the water in the user-side heat exchanger 5 is being cooled by the operation of the compressor 1, but there is a difference in temperature between the water inlet section 5a and the water outlet section 5b because the water is not flowing. It can be determined that there is no .

In the unlikely event that 2<ITi-Tol, it is determined that the air conditioning circulating water has been cut off, and the process proceeds to step 50, where the compressor 1 is stopped.

If 2 < 1Ti-To l, in step 45, the measurement of the compressor operating time is ended.Step 45)
, the dead time accumulated in the memory 20 is reset.

Next, the process proceeds to step 46, where it is determined whether Ti≦T as described above. If the inlet water temperature Ti is lower than the set water temperature T8, the process proceeds to step 47, where the compressor 1 is thermo-stopped, and then , the system waits for the temperature of the air conditioning circulating water to rise (step 48).

Next, in step 49, after the compressor 1 is stopped, the inlet water temperature Ti rises due to the temperature rise of the circulating water for air conditioning, and if the inlet water temperature Ti rises by, for example, 3 deg C or more with respect to the preset temperature T8, Ti) When T is +3, it is determined that the compressor is in operation, and the process returns to step 38.
Then, the blower 3 is operated, and thereafter, the operation φ and stop are repeated according to the above flowchart.

In addition, although the above embodiment describes the case of an air-cooled type air conditioner exclusively for cooling, the same applies to a water quality type.
Furthermore, the same effects as in the above embodiment are simulated in a heat pump type air conditioner.

〔Effect of the invention〕

As described above, the present invention is configured such that when the temperature detection signal generated from the second temperature detector that detects the temperature of the water inlet of the user-side heat exchanger reaches a signal level corresponding to a preset temperature, the pressure m! 11 Operation stop The compressor operation stop means operates the compressor at full capacity based on the output signal generated from the water temperature determination means, and the compressor operation stop means starts compressor operation from the time when the output of the compressor operation stop water temperature determination means is supplied to the compressor operation time measurement means. The operating time of the machine is measured, and when a certain period of time has elapsed, the signal level difference between the temperature detection signal of the first temperature detector that detects the temperature of the water outlet of the heat exchanger on the user side corresponds to the set temperature difference. If the signal level is not reached, the compressor operation stop means will stop the compressor operation based on the signal generated from the inlet/outlet temperature difference determination means. Even if the water stops flowing, it can be predicted that the water will freeze inside the user-side heat exchanger, so the fear of freezing inside the user-side heat exchanger can be eliminated.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of an embodiment of the air conditioner of the present invention, Fig. 2 is a circuit diagram showing the electrical connections of the air conditioner shown in Fig. 1, and Fig. 3 shows the operation of the same air conditioner. Show 70
-Chart, FIG. 4 is a block diagram of a conventional air conditioner, and FIG. 5 is an electric circuit diagram of a control section of the conventional air conditioner. 1... Compressor, 2... Non-use side heat exchanger, 7...
Fan; oil unit, 5...user side heat exchanger, 9
... Second temperature detector, 10... First temperature detector, 11... Compressor operation stop water temperature determination means, 12...
Compressor operating time measuring means, 13... Compressor operating/stopping means, 14... Inlet/outlet bearing temperature difference determining means. Note that the same reference numerals in the figures indicate the same or corresponding parts. Figure 1 Figure 2! ? Fig. 3 Fig. 4 Fig. 5 ``A Written amendment (spontaneous) 1985, 10 π0 Day 2, Title of invention Air conditioner 3, Relationship to the case of the person making the amendment Patent applicant address Chiyoda, Tokyo 2-2-3 Marunouchi, Ward Name (601) Mitsubishi Electric Corporation Representative Moriya Shiki 4, Agent address: Inside Mitsubishi Electric Corporation, 2-2-3 Marunouchi, Chiyoda-ku, Tokyo '-7~''~・, 5. Subject of amendment (1) Column for detailed explanation of the invention in the specification (2) Column 6 for brief explanation of drawings in the specification, Contents of amendment (1) "First of all," on page 3, line 6 of the specification "Figure 5" is corrected to "First, Figure 4." (2) On page 3, line 8, "to exchange 3" is completely corrected to "to exchange 2." (3) "Compression operation" on page 10, line 15 of the same page has been changed to "compressor operation"
I am corrected. (4) On page 10, line 19, all "inlet/outlet water concentrations" are corrected to "inlet/outlet water temperature difference." (5) On page 15, line 5, "water flow" is corrected to "water temperature." (6) "In step 45," on page 16, lines 5-6.
Delete. (7) On page 17, line 18, "0 temperature inlet/outlet" is corrected to "inlet/outlet water temperature source." (8) On page 18, line 18, "inlet/outlet water concentration" is corrected to "inlet/outlet water temperature."

Claims (1)

[Claims] A refrigerant compressor that sucks in refrigerant and compresses and discharges it, a non-use side heat exchanger that exchanges heat between the refrigerant supplied from this compressor and the fluid to be heat exchanged, and a fan coil unit that connects the refrigerant supplied from the compressor with the heat exchange fluid. A user-side heat exchanger that exchanges heat with the air-conditioning circulating water that is circulated between the air conditioning load device, detects the outlet water temperature of this user-side heat exchanger, and generates an output signal according to this outlet water temperature. a first temperature detector; a second temperature detector that detects the inlet water temperature of the user-side heat exchanger and generates an output signal according to the inlet water temperature; the temperature is generated from the second temperature detector; Compressor operation stop water temperature determination means that generates an output signal for operation or stop when the temperature detection signal reaches a signal level corresponding to a preset temperature; and an operation output signal generated from the compressor operation stop water temperature determination means. is supplied, the compressor operating time measuring means starts measuring the operating time of the compressor, and when the time measured by the compressor operating time measuring means exceeds a certain value, the temperature is generated from the first temperature detector. An inlet/outlet water temperature temperature difference that generates an output signal when the signal level difference between the temperature detection signal generated by the second temperature detector and the temperature detection signal generated from the second temperature detector does not reach a signal level difference corresponding to a preset temperature difference. Judgment means,
Compressor operation stop means operates or stops the compressor based on an output signal generated from the compressor operation stop water temperature determination means and stops the compressor based on an output signal generated from the inlet and outlet water temperature difference determination means. Air conditioner equipped.