JPH0749897B2 - Absorption refrigerator operation monitoring device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an operation monitoring device for an absorption chiller, and in particular,
The present invention relates to an operation monitoring device for an absorption refrigerating machine, which is suitable for early detection of a failure, a troble, etc., and so-called pre-maintenance.

[Conventional technology]

As a conventional operation monitoring device for an absorption chiller, there is known a device for monitoring the concentration during dilution operation as described in Japanese Patent Publication No. 61-32586.

In an absorption chiller, when it is operating under a certain load condition and the operation is terminated because the load is reduced, immediately stop the chiller operation and stop auxiliary equipment such as a regenerator pump and a refrigerant pump. If left unattended, natural heat dissipation, etc.
The system temperature drops, and crystal precipitation occurs in the solution on the outlet side of the low temperature solution heat exchanger, which had a high concentration just before the shutdown. When crystal precipitation occurs, at the time of next start, there is a possibility that the pipe may be blocked or the crystal may flow into the pump and damage the pump, resulting in operation failure. Therefore,
Even after the refrigeration operation is stopped, the pumps are continuously operated, the solution having a lower concentration contained in the system is mixed with the high-concentration solution, and the dilution operation for preventing the precipitation of crystals is performed.

In the above-mentioned known example, in the prior art prior to that, it is wasteful of electric power that the dilution operation is always executed for a predetermined time regardless of the state of the solution, so that the condensed refrigerant temperature or the regenerator pressure, the regenerator outlet solution temperature , And the solution temperature at the solution heat exchanger outlet are detected, and the concentration margin up to the solution concentration or crystal precipitation is calculated from this detected value and the solution concentration curve, and when the solution concentration or the concentration margin reaches the specified value. , Has proposed an operation method that automatically ends the dilution operation.

[Problems to be solved by the invention]

The above-mentioned prior art is to determine whether or not the solution has become sufficiently thin after stopping the refrigeration operation and prevent crystal precipitation.

However, considering actual operation, crystal precipitation may occur even during freezing operation. In other words, even though all absorption refrigerators are designed with sufficient margin and durability, deterioration of parts is unavoidable during long-term operation, and corrosion and air leakage occur, as with all equipment. Since the fear is not complete, there is a possibility of crystal precipitation.

In each of the above-mentioned conventional examples, attention is paid only to the crystal precipitation after the refrigeration operation is stopped, and it is not a method of monitoring the state in the entire period of the refrigeration operation.

Corrosion and air leakage of refrigerating machine components gradually progress and do not lead to an accident immediately, but eventually the system will be down. Therefore, it is desirable to detect it in a minor amount and realize pre-maintenance.

Therefore, an object of the present invention is to provide an operation monitoring device for an absorption chiller, which enables early detection of failures and troubles and the like to realize pre-maintenance.

[Means for solving problems]

In order to achieve the above object, the present invention provides an absorber outlet solution temperature of an absorption refrigerator including an evaporator, an absorber, a condenser, a regenerator, an evaporator refrigerant temperature, a high temperature regenerator outlet solution temperature,
Low temperature regenerator condensate drain temperature, low temperature regenerator outlet solution temperature,
A means for measuring the refrigerant temperature of the condenser outlet, calculating the solution concentration at the absorber outlet, the low temperature regenerator outlet, and the high temperature regenerator outlet from these measured values and the solution concentration diagram, and the cold water outlet of the absorption refrigerator. A means for measuring the temperature, cooling water inlet temperature, heat input, etc., and calculating the solution concentration at the absorber outlet, high temperature regenerator outlet, low temperature regenerator outlet in the theoretical cycle from these measured values and the heat transfer performance of the refrigerator. And an operation monitoring device for an absorption chiller comprising means for comparing the solution concentration based on the measured value and the solution concentration diagram with the solution concentration based on the measured value and the theoretical cycle to determine whether there is an abnormality. It is a proposal.

[Action]

The concentration of the solution can be calculated from the temperature and pressure of the solution using a concentration diagram (During diagram) of the solution. The pressure can be calculated by measuring the refrigerant temperature and using a steam table.

On the other hand, if the cold water inlet / outlet temperature, the cooling water inlet / outlet temperature, the amount of cold water, and the amount of cooling water are known, theoretical calculation of the cycle is possible, and the solution concentration that should be designed can be calculated. Here, in general, the amount of cold water and the amount of cooling water are fixed in many cases. Therefore, when the cold water outlet temperature, the cooling water inlet temperature, and the heat input amount as a value representing the load are measured, the solution concentration that should be present is determined. It can be calculated.

By comparing the solution concentrations calculated by such different methods, it is possible to determine whether the operating state is normal.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a system diagram showing an absorption refrigerator having an operation monitoring device according to the present invention. First, the system configuration of the basic absorption refrigerator will be described. In the figure, 1 is 1/10 inside
An evaporator 2 which is kept at 0 atmospheric pressure and which cools the cold water 3 in the pipe by evaporating the refrigerant (water) sprayed on the outer surface of the pipe, 2 is a refrigerant pump,
4 is cooling water, 5 is an absorber in which the concentrated solution absorbs the refrigerant vapor from the evaporator 1 to form a dilute solution, 6 is a solution pump for delivering the dilute solution, 7 is a heat exchanger for the concentrated solution and the dilute solution, 8 Is a high temperature regenerator that heats a rare solution obtained by absorbing the refrigerant vapor generated in the evaporator 1 in the absorber 5 with a burner to separate it into a refrigerant vapor and a concentrated lithium bromide solution. 9 is a refrigerant vapor generated in the high temperature regenerator 8. A low temperature regenerator that heats the lithium bromide solution to separate the refrigerant by means of a condenser 10, which condenses the refrigerant vapor from the low temperature regenerator 9 with the cooling water 4 and the refrigerant condensed in the pipe of the low temperature regenerator 9 together. It is a condenser to send to 1.

In the absorption chiller having such a basic configuration, water as a refrigerant is dispersed by the refrigerant pump 2 onto the heat transfer tubes in the evaporator 1, and the heat of the cold water 3 passing through the heat transfer tubes is taken and evaporated.
A freezing effect occurs here. The evaporated refrigerant vapor flows into the absorber 5 kept at a low pressure by the cooling water 4, and is absorbed by the solution bromide solution sprayed by the solution pump 6. Therefore, the lithium bromide solution becomes a dilute solution. This dilute solution is supplied to the heat exchanger 7 by the solution pump 6.
After that, a part is sent to the high temperature regenerator 8 and the rest is sent to the low temperature regenerator 9. In the high temperature regenerator 8, it is heated by a direct heat source such as gas and separated into vapor and concentrated solution. The low temperature regenerator 9 is heated by the steam generated in the high temperature regenerator 8 and separated into steam and concentrated solution. The solution thus concentrated passes through the heat exchanger 7 again and is introduced into the absorber 5. The drain that has heated and condensed the solution in the low temperature regenerator 9 is guided to the condenser 10. On the other hand, the steam generated in the low temperature regenerator is condensed in the condenser 10. The condensed refrigerant is sent to the evaporator 1 to complete the cycle.

According to the present invention, the temperature sensors 12 to 19 are arranged at the key points of the absorption refrigerator having such a basic structure and operation, and the fuel consumption (heat input) sensor 20 of the high temperature regenerator 8 is provided. The signal from the above is taken into the operation monitoring device 11, the solution concentration and the desired solution concentration are calculated, and the presence or absence of abnormality is judged by comparing the two concentrations.

More specifically, 12 is an absorber solution temperature sensor, 13 is a refrigerant temperature sensor, 14 is a high temperature regenerator solution temperature sensor, 15 is a low temperature regenerator condensed refrigerant temperature sensor, 16 is a low temperature regenerator solution temperature sensor, and 17 is A condenser condensed refrigerant temperature sensor. The signals from these sensors 12 to 17 are, as shown in the upper part of FIG. 2, the absorber outlet solution concentration ξ _A , the high temperature regenerator outlet solution concentration ξ _HG ,
Used to calculate the cold regenerator outlet solution concentration ξ _LG .

On the other hand, the cold water outlet temperature sensor 19, the cooling water inlet temperature sensor 18,
And the signal from the fuel consumption sensor 20 is used to calculate the solution concentrations ξ ′ _A , ξ ′ _HG , ξ ′ _LG that should theoretically exist from the cycle, as shown in the middle part of FIG.

Abnormality depends on whether the solution concentrations ξ _A , ξ _HG , and ξ _LG calculated in this way and the solution concentrations ξ ′ _A , ξ ′ _HG , and ξ ′ _LG that should be present hold the relationship shown in the lower part of FIG. Determine if In these relational expressions, α, β and γ are correction coefficients. If the concentration should be higher than that, it is determined to be normal, and if it is extremely low, it is determined to be abnormal, and an alarm is issued, for example.

〔The invention's effect〕

In the present invention, since the theoretically desired concentration and the actual concentration are compared, a cycle abnormality can be detected at an early stage regardless of the operating state, and measures are taken before the system goes down as a whole. Therefore, preventive maintenance of the absorption refrigerator is possible.

[Brief description of drawings]

FIG. 1 is a system diagram showing the configuration of an absorption refrigerator having an operation monitoring device according to the present invention, and FIG. 2 is a flow chart showing the function of the operation monitoring device. 1 ... Evaporator, 2 ... Refrigerant pump, 3 ... Cold water, 4 ... Cooling water, 5 ... Absorber, 6 ... Solution pump, 7 ... Heat exchanger, 8 ... High temperature regenerator, 9 ...... Low temperature regenerator, 10 ...... Condenser, 11 ...... Operation monitoring device, 12 to 19 ...... Temperature sensor, 20 ...... Fuel consumption (heat input) sensor.

Claims (1)

[Claims] 1. An operation monitoring device for an absorption chiller including an evaporator, an absorber, a condenser, a regenerator, etc., wherein the solution temperature at the outlet of the absorber, the temperature of the refrigerant at the evaporator, the temperature of the solution at the outlet of the high temperature regenerator, and the low temperature regenerator. Condensate drain temperature, low temperature regenerator outlet solution temperature, condenser outlet refrigerant temperature, etc. are measured, and the solution concentrations at the absorber outlet, low temperature regenerator outlet and high temperature regenerator outlet are determined from these measured values and the solution concentration diagram. A means for calculating, a cold water outlet temperature, a cooling water inlet temperature, a heat input amount, etc. of the absorption chiller are measured, and from the measured values and the heat transfer performance of the chiller, the absorber outlet, high temperature regeneration in a theoretical cycle. Means for calculating the solution concentration at the outlet of the reactor and the outlet of the low temperature regenerator, and comparing each solution concentration based on the measured value and the solution concentration diagram with each solution concentration based on the measured value and the theoretical cycle to determine whether there is an abnormality. A way to judge Operation monitoring device of the absorption type refrigerator characterized by comprising.