JPH0868569A - Ammonia absorption type heat pump system - Google Patents

Abstract

PURPOSE: To provide a leakage detecting sensor for detecting and recognizing the dielectric constant change in an ammonia gas atmosphere leaked into an outdoor unit in the sensor of an ammonia absorption type heat pump system. CONSTITUTION: When ammonia is leaked into an outdoor unit 21, the pressure in a refrigerant circuit is varied, which is recognized by an ammonia leakage detector 26 via a pressure sensor 22. On the other hand, the load applied to a solution pump 10 is also varied corresponding to the pressure change at the time of leaking the ammonia, which is recognized by the detector 26 as a current change. Particularly, in the case of the abnormal state of the ammonia leakage at the time of operating, it can be recognized by both the types of the sensors, and can be recognized by the operation of the sensor 22 for the ammonia leakage during stopping.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ammonia leakage detection system for an ammonia absorption heat pump system.

[0002]

2. Description of the Related Art As a conventional ammonia leak detection method, a semiconductor detection method in which a leaked ammonia gas is sucked to detect a change in the resistance of a semiconductor is generally used.

[0003]

However, the above-mentioned conventional method is not capable of responding to aged deterioration due to the fact that the semiconductor method is slightly inferior in corrosion resistance to gas in a normal atmosphere, or is affected by dust adhesion. The tolerance of is narrow. As a result, there is a drawback that stable responsiveness cannot be expected against an emergency of ammonia leakage, and it remains as a material for concern about reliability. The present invention solves the above-mentioned drawbacks, and is intended to improve reliability with little change over time.

[0004]

According to the present invention, there is provided an ammonia leak detecting means for achieving the above object, which is a method for detecting a change in permittivity of gas in an atmosphere when ammonia is leaking, a method for detecting a pressure change in a refrigerant circuit, or a solution. An indirect current detection method that detects current changes due to pump load changes, or a light detection method that detects the light intensity of the optical spectrum by arranging a light emitter and a light receiver with a gas in the atmosphere inside the outdoor unit sandwiched between them. In addition, a self-correction circuit that corrects output changes due to secular changes each time is discriminated between pressure fluctuations due to normal system heat load changes, pressure fluctuations during system startup and shutdown, and abnormal pressure fluctuations during ammonia leakage. It has a configuration in which abnormality determining circuits for performing the above are combined.

[0005]

In the present invention, the dielectric constant change detection method of the present invention detects a change in the dielectric constant of the gas between two electrodes arranged in the atmosphere of the outdoor unit and is not directly connected to the refrigerant circuit. It has a function to detect leaks. The part that changes with long-term use may be due to dirt or corrosion on the electrode surface, or adhesion of dust, but considering the overall capacitance between the electrodes, the contribution of the dielectric constant of the gas part is relatively large. Since it is large, the influence of the permittivity due to dirt, corrosion, dust adhesion, etc. on the electrode surface is small, but with an emphasis on safety, the change in the permittivity and the degree of contamination due to dirt or corrosion on the electrode surface or dust adhesion etc. It also contains a first anomaly warning circuit that monitors and issues a cleaning warning.

The indirect current detection method for a solution pump detects a load change applied to the solution pump as a current change in response to an abnormal change in pressure when ammonia leaks, and is not affected by gas or dust in the atmosphere. Hateful.

Since the pressure change detection method is a method in which a pressure sensor is attached to the refrigerant circuit to directly detect the pressure change when ammonia is leaked, the response output is higher than that of the solution pump current change detection method, and therefore the detection capability is high. Have a function. Furthermore, the influence of gas and dust in the atmosphere is small. However, the system pressure change factor can naturally be the system pressure change due to normal heat load or the pressure change during the system start-up / shut-down process. Since the frequency of occurrence of changes is low, a learning function consisting of the number and frequency of data acquisition determines the pressure change when ammonia is leaking, and the pressure change due to normal heat load is It is equipped with a discrimination function that utilizes changes that occur more slowly than changes in pressure.

The photo-detection method detects changes in the intensity and the spectrum that penetrates the leaked ammonia in the light emitted from the light-emitting body having a predetermined spectrum. If the light transmittance changes due to dirt, corrosion, dust adhesion, etc. on the surface of the body, it will affect the detection output, but it can be restored to the original state by cleaning the surface. Has a built-in second abnormality warning circuit that monitors the degree of contamination from the light transmission and issues a warning for cleaning. In addition, the self-correction circuit is subject to some aging deterioration in any of the detection methods, so normally, when there is no leakage, data is taken in at regular intervals, output fluctuations are constantly monitored, and zero adjustment is performed. It is constructed so as to always secure a necessary operation output of the leakage diffusion suppressing means at the time of abnormality.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, a regenerator 3 having a burner fan 1 and a burner section 2 is provided to convert the concentrated ammonia solution into a high temperature water gas by heating the combustion gas, and the ammonia water gas having a high concentration of ammonia. A rectifier 4 for separating and refining a gas and a dilute solution of ammonia into a solution, a condenser 5 for condensing and liquefying the high-concentration ammonia, and an evaporator 7 for further re-evaporation via an expansion valve 6.
And an absorber 9 for taking in the ammonia solution of the dilute solution through the pressure reducing valve 8 and absorbing the ammonia gas evaporated in the evaporator 7 to regenerate it into the ammonia solution of the concentrated solution.
A solution pump 10 for feeding the concentrated ammonia solution regenerated here to the regenerator 3 and a solution heat exchanger 11 having a heat exchange function between the concentrated ammonia solution and the dilute ammonia solution. From the secondary chilled water circuit of the evaporator 7 to the first four-way valve 12
First stop valve 14 that communicates with the indoor heat exchanger 13 via the second stop valve 15 that returns from the indoor heat exchanger 13 and is connected to the next, and the first water circulation pump 1
6, the second four-way valve 17 and the secondary cold water circuit of the evaporator 7 are sequentially connected by a water pipe, and cold water obtained in the evaporator 7 is conveyed to an indoor heat exchanger for cooling. An outdoor heat exchanger 19 having a cooling circuit, a secondary cooling water circuit of the condenser 5, the first four-way valve 12, and a second blower fan 18,
The second water circulation pump 20, the second four-way valve 17, the absorber 9
The secondary cooling water circuit and the secondary cooling water circuit of the condenser 5 are sequentially connected by water pipes, and hot water obtained from the condenser is transferred to the outdoor heat exchanger to radiate heat, and the heat radiation circuit is outdoor. Machine 21
The heat pump is constructed by arranging the above.

The hot water obtained in the condenser by switching the first four-way valve and the second four-way valve is transferred to the indoor heat exchanger and used as heating heat, while the amount of outside air heat obtained in the outdoor heat exchanger. Is transported to the evaporator and the refrigerant in the evaporator is heated and used as the amount of heat of evaporation. Also, a pressure sensor 22 for detecting a pressure change in the refrigerant circuit.
In addition to the pump drive power source 23 that drives the solution pump 10 and the current detector 25 that detects the current flowing in the solution pump through the resistor 24, the outputs of the pressure sensor 22 and the current detector 25 are ammonia leaks. The ammonia leak detection circuit is a self-correction circuit that corrects secular changes so that the output is always zero when there is no output, and an abnormality determination circuit that distinguishes pressure fluctuations during normal system operation and pressure changes during ammonia leakage. The ammonia absorption heat pump system is built in the outdoor unit 21 by arranging the ammonia leakage detection means, which is built in 26 and has both the pressure change detection method and the solution pump current change detection method, in the outdoor unit 21.

In the above structure, ammonia is used as the outdoor unit 2
1 leaks, the pressure in the refrigerant circuit fluctuates, and this changes via the pressure sensor 22 to the ammonia leak detection circuit 2
6, the load applied to the solution pump 10 also changes corresponding to the pressure change at the time of ammonia leakage, and this is recognized by the ammonia leak detection circuit 26 as a current change via the current detector 25. In particular, an abnormal situation of ammonia leakage during operation can be recognized by both types of detectors, and ammonia leakage during stoppage can be recognized by the operation of the pressure sensor 22.

Next, another embodiment of the present invention will be described with reference to FIGS. 2 and 3 are different from the above-described embodiment in that the ammonia leak detection means of the dielectric constant change detection method arranged in the outdoor unit 21 is not directly connected to the refrigerant circuit or the electric circuit of the solution pump. FIG. 2 shows a capacitor 30 in which the gas between two electrodes arranged in the atmosphere inside the outdoor unit 21 is formed as a dielectric.
Inductor 31 and excitation source 3 formed by an induction coil and
And a second ammonia detection circuit 34 that detects and recognizes a change in the dielectric constant in the atmosphere that changes in response to ammonia leakage as a voltage change via the resistor 33. There is.

Further, FIG. 3 shows a capacitor C ₀ 35 formed by using a gas between two electrodes arranged in an atmosphere in the outdoor unit 21 as a dielectric and impedances Z ₁ 36 and Z ₂ 3
7, Z ₃ 38 and bridge resistor R 39 form a Wheatstone bridge circuit, the drive power source E 41 is applied, and the balance of the Wheatstone bridge circuit is lost according to the dielectric constant that changes when ammonia leaks, It is composed of an ammonia leakage detecting means including a third ammonia leakage detecting circuit for detecting and recognizing a voltage change between R.
According to the configurations of FIGS. 2 and 3, since the permittivity of the gas in the atmosphere changes when ammonia leaks, the resistances 33 and 39 appearing corresponding to the change in the capacitance of the capacitors 30 and 35 accordingly. Ammonia leakage can be recognized by detecting the terminal voltage change, and it can be detected without directly connecting to the refrigerant circuit.
Ammonia leakage detection means is composed of a second ammonia detection circuit and a third ammonia detection circuit having a first abnormality warning circuit for monitoring and warning the degree of contamination from the dielectric constant that changes due to dirt, corrosion, and dust adhering to 0 and 35. Therefore, there is an effect that high safety and reliability can be obtained.

Still another embodiment of the present invention will be described with reference to FIG. 4 is different from the above-described embodiment in that the ammonia leak detecting means is composed of a light detecting method. This is because the luminous body 42 is arranged so as to sandwich the gas in the atmosphere inside the outdoor unit 21. , The light receiving body 43, and a detection circuit for detecting the light spectrum and intensity from the light emitting body 42 through the light receiving body 43, and changes due to dirt, corrosion, and dust adhering to the surfaces of the light emitting body 42 and the light receiving body 43. It is composed of an optical analyzer 44 having an abnormality warning circuit that monitors and issues a warning as the degree of contamination based on the degree of light transmission. According to this configuration, the change in the light transmittance of the gas in the atmosphere at the time of ammonia leakage is detected and recognized and can be detected without directly connecting the sensor to the refrigerant circuit. The surface of the light-emitting body 42 and the light-receiving body 43. Since it is possible to constantly monitor dirt, corrosion, dust adhesion, etc., high safety and reliability can be obtained.

[0016]

As described in the above embodiments, according to the ammonia leakage detecting means of the ammonia absorption heat pump system of the present invention, the following effects can be obtained.

(1) A pressure sensor is attached to the refrigerant circuit to detect a pressure change, a self-correction circuit for preventing an output drift due to aging, a normal pressure change and an abnormal pressure at the time of ammonia leakage. Since the ammonia leakage detection means is composed of the abnormality determination circuit for identifying the change, the pressure change in the refrigerant circuit can be directly monitored, so that the response is good, the influence of the gas in the atmosphere is small, and the safety and reliability are high.

(2) An indirect current detection system that detects a pressure change when ammonia leaks as a current change of the solution pump, a self-correction circuit that prevents output drift due to aging, and a normal pressure change and ammonia leak. Since the ammonia leakage detection means is composed of an abnormality determination circuit that identifies abnormal pressure changes, it has good responsiveness to pressure changes at the time of leakage, and the effect of gas in the atmosphere is small, so safety is improved. Highly reliable.

(3) A permittivity change detection method for detecting a change in the permittivity of gas in the atmosphere at the time of ammonia leakage as a change in the capacitance of the capacitor from a parallel resonance circuit or a Wheatstone bridge circuit method. A self-correction circuit that has a zero adjustment function to prevent output drift due to aging, and an abnormal warning that monitors the change in the dielectric constant due to normal capacitor dirt, corrosion, dust adhesion, etc. as a dirt level and issues a cleaning warning. Since the ammonia leakage detecting means is constituted by the circuit, it is not attached to the refrigerant circuit, so that the cost is low and measures against aging are taken, so that safety and reliability are high.

(4) A light detecting system for arranging a light emitting body and a light receiving body in the atmosphere inside the outdoor unit to detect a spectrum of light and a change in the refractive index of the light from the light emitting body when ammonia leaks, and an output drift due to a secular change. A self-correction circuit with a zero-adjustment function to prevent it, and a change in permeability due to normal capacitor dirt, corrosion, dust adhesion, etc. is monitored as a dirt level, and an abnormality warning circuit that issues a cleaning warning provides ammonia leakage detection means. It is highly safe and reliable because it has a low cost because it is not configured and attached to the refrigerant circuit and measures against aging are taken.

(5) Since a double or triple safety device is obtained by using some of the various ammonia leakage detecting means of the present invention, the cost and reliability are high.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an ammonia absorption heat pump system according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of ammonia leakage detection means according to another embodiment of the present invention.

FIG. 3 is a configuration diagram of the ammonia leakage detection means.

FIG. 4 is a block diagram of the ammonia leakage detection means.

[Explanation of symbols]

1 burner fan 2 burner part 3 regenerator 4 rectifier 5 condenser 6 expansion valve 7 evaporator 8 pressure reducing valve 9 absorber 10 solution pump 11 solution heat exchanger 12 first four-way valve 14 first stop valve 15 second Stop valve 16 First water circulation pump 17 Second four-way valve 18 Second blower fan 19 Outdoor heat exchanger passage 20 Second water circulation pump 21 Outdoor unit 22 Pressure sensor 23 Pump drive power supply 24 Resistance 25 Current detector 26 Ammonia leak detection circuit 30 Capacitor 31 Inductor 32 Excitation Source 33 Resistance 34 Second Ammonia Leakage Detection Circuit 35 Capacitor C ₀ 36, 37, 38 Impedance 39 Bridge Resistance R 40 Third Ammonia Leakage Detection Circuit 42 Luminescent Body 43 Photoreceptor 44 Emission Analyzer

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Masaru Ito 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Takahito Ishii 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (10)

[Claims] 1. A burner fan, a burner section, a regenerator for regenerating a concentrated solution of ammonia solution into a high temperature water gas by heating the combustion gas, and the ammonia water gas of a high concentration ammonia gas and a dilute solution. A rectifier for separating into an aqueous ammonia solution, a condenser for condensing and liquefying the high-concentration ammonia, an evaporator for further re-evaporation via an expansion valve, and an ammonia aqueous solution of the dilute solution, An absorber that absorbs the ammonia gas evaporated in the evaporator and regenerates it into a concentrated solution of ammonia solution, a solution pump that feeds the concentrated solution of ammonia solution to the regenerator, and a solution of the concentrated solution of ammonia solution and the diluted solution. A refrigerant circuit formed by connecting a solution heat exchanger having a heat exchange function between aqueous ammonia solutions to the regenerator by a pipe, and an evaporator. Stop valve 1 communicating with the indoor heat exchanger from the cold water circuit via the first four-way valve, stop valve 2 connected to the next by allegiance from the indoor heat exchanger,
And a cooling circuit formed by connecting a first water circulation pump, a second four-way valve, and the evaporator secondary chilled water circuit in this order with a water pipe, and a secondary chilled water circuit of the condenser to the first four-way valve,
An outdoor heat exchanger having a second blower fan, a second water circulation pump, a second four-way valve, a secondary cooling water circuit of the absorber, and a secondary cooling water circuit of the condenser are sequentially connected by a water pipe. And an ammonia absorption heat pump outdoor unit composed of a heat dissipation circuit, which comprises ammonia leakage detection means for controlling leakage diffusion suppressing means for detecting leakage of ammonia gas into the outdoor unit and suppressing leakage diffusion. Ammonia absorption heat pump system. 2. Ammonia leakage provided with a self-correction circuit for taking in the output of an ammonia leakage detection sensor at a constant time interval during a period when there is no ammonia leakage, detecting an output change due to secular change each time, and adjusting to zero output. The ammonia absorption heat pump system according to claim 1, which comprises a detection means. 3. An ammonia leakage detecting means comprising a pressure sensor for detecting a fluctuating pressure in the ammonia absorption heat pump which changes in response to ammonia leaking into the outdoor unit in the refrigerant circuit of the ammonia absorption heat pump. The ammonia absorption heat pump system according to claim 1 or 2, which is provided. 4. An ammonia leakage detecting means for detecting an electric current of a solution pump which changes in response to a pressure in an ammonia absorption heat pump which changes corresponding to ammonia leaking into an outdoor unit. Or the ammonia absorption heat pump system according to claim 2. 5. A resonance circuit is constructed by connecting an excitation source via a resistor to a parallel circuit of a capacitor formed of a gas in an atmosphere inside an outdoor unit as a dielectric and an inductor formed of an induction coil to form an ammonia leak. The ammonia according to claim 1 or 2, which comprises ammonia leakage detection means for detecting and recognizing a terminal voltage via a resistor as a change in the dielectric constant in the atmosphere that changes in accordance with the above, as a current change in the resonance circuit. Absorption heat pump system. 6. A capacitor C ₀ formed by using a gas in an atmosphere in an outdoor unit as a dielectric and impedances Z1, Z.
A Wheatstone bridge circuit is formed with 2, Z3 and the bridge resistor R, and the drive power source E is applied to detect the voltage appearing between the bridges according to the change in the dielectric constant in the atmosphere that changes corresponding to ammonia leakage. The ammonia absorption heat pump system according to claim 1 or 2, which is constituted by an ammonia leakage detection means comprising the above. 7. A first abnormality warning circuit for monitoring the degree of contamination from a dielectric constant that changes due to dirt, corrosion, and dust adhering to a capacitor formed by using a gas in the atmosphere in an outdoor unit as a dielectric and issuing a warning. The ammonia absorption heat pump system according to claim 1 or 2, comprising ammonia leakage detection means including a dual ammonia detection circuit and a third ammonia detection circuit. 8. A light-emitting body and a light-receiving body, which are arranged so as to sandwich a gas in an atmosphere inside the outdoor unit, and an optical analyzer which detects an optical spectrum and a light intensity from the light-emitting body through the light-receiving body.
The ammonia absorption heat pump system according to claim 1 or 2, comprising ammonia leakage detection means for detecting an optical spectrum from the light emitter as a change in light intensity received by the light receiver in response to ammonia leakage. 9. The degree of contamination is monitored from the light transmittance which changes due to dirt, corrosion and dust adhering to the surface of the light emitter and the light receiver.
The ammonia absorption heat pump system according to claim 1 or 2, comprising ammonia leakage detection means including an optical analyzer having an abnormality warning circuit for issuing a warning. 10. The ammonia absorption heat pump system according to claim 1 or 2, wherein the ammonia leakage detecting means according to any one of claims 3 to 8 is used in combination to provide a multiple safety function.