JPH06323683A - Absorptive refrigerator - Google Patents

Abstract

PURPOSE:To provide an absorptive refrigerator in which concentration of absorption liquid can be accurately regulated irrespective of disturbance. CONSTITUTION:The absorptive refrigerator comprises an evaporator 6 for evaporating refrigerant liquid, an absorber 5 for absorbing refrigerant vapor generated from the evaporator 6 to the liquid, a liquid reservoir 5a communicating with the evaporator 6 and the absorber 5, and a regenerator 1 for regenerating the liquid diluted with the refrigerant, wherein the reservoir 5a, the regenerator 1 and the absorber 5 are connected via absorption liquid circulation passages 10, 11, 13, and a condenser 7 is connected to the evaporator 6 via a refrigerant liquid supply passage 21 through a flow regulating means F. Further, the refrigerator comprises a coolant temperature detecting means Sw for detecting a temperature of coolant flowing to the regenerator 1 and an absorption liquid temperature detecting means Sy for detecting a temperature of the absorption liquid regenerated by the regenerator 1, and flow control means 31, 32, 33 for controlling the means F based on detection information of the means Sw and Sy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporator for evaporating a refrigerant liquid, an absorber for absorbing a refrigerant vapor generated in the evaporator into an absorbing liquid, and a liquid pool communicating with the evaporator and the absorber. And a regenerator for regenerating an absorption liquid diluted with a refrigerant, the liquid pool portion, the regenerator and the absorber are connected by an absorption liquid circulation path, a condenser and the evaporator Relates to an absorption refrigerating machine connected by a refrigerant liquid supply passage having a flow rate adjusting means interposed therebetween.

[0002]

2. Description of the Related Art In such an absorption refrigerating machine, there is a risk that the absorbent may crystallize when the concentration of the absorbing liquid exceeds a proper range.
Further, if the concentration is lower than the proper range, the absorption capacity of the absorption liquid for absorbing the refrigerant vapor is lowered and the refrigeration capacity is reduced, so that the concentration of the absorption liquid needs to be adjusted within the proper range. Conventionally, while providing a refrigerant liquid storage chamber for storing the refrigerant liquid in the condenser,
A level sensor or the like for detecting the amount of refrigerant liquid stored in the refrigerant liquid storage chamber is provided, and the concentration of the absorbing liquid is adjusted by controlling the flow rate adjusting means based on the detection information of the level sensor.

[0003]

However, in the above-mentioned conventional absorption refrigerator, the refrigerant liquid storage chamber and the level sensor must be provided, and the level sensor is provided with the detection section in the condenser and the detection information. Since it has to be provided in a state of being led out of the condenser, there is a problem that the configuration for adjusting the concentration of the absorbing liquid becomes complicated.

Incidentally, in order to solve the above-mentioned problems,
By providing a temperature sensor that detects the inflow temperature of the cooling water to the absorber that affects the absorption capacity of the absorbing liquid, and performing feedforward control of the flow rate adjusting means based on the detection information of the temperature sensor, the concentration of the absorbing liquid There is something to adjust.

However, due to fluctuations in operating conditions (adjustment of the amount of heat input for adjusting the regeneration capacity of the regenerator, adjustment of the circulation amount of the absorption liquid circulating in the absorption liquid circulation path, etc.), the condensation capacity of the condenser Since the regeneration capacity of the regenerator fluctuates, the amount of refrigerant liquid retained in the condenser fluctuates, that is, the amount of refrigerant liquid in the absorbing liquid circulating in the absorbing liquid circulation path changes. fluctuate. Therefore, in the one that feed-forward controls the flow rate adjusting means based on the detection information of the temperature sensor, no measure is taken against the fluctuation of the refrigerant liquid retention amount in the condenser, and the absorption liquid is changed by the fluctuation of the operating state. In some cases, it may not be possible to maintain the concentration in the appropriate range, and it has not been possible to reliably prevent the crystallization of the absorbent and the deterioration of the refrigerating capacity.

The present invention has been made in view of the above circumstances, and an object thereof is to make it possible to reliably prevent the crystallization of the absorbent and the deterioration of the refrigerating capacity with a simple structure. It is in.

[0007]

The absorption refrigerating machine according to the present invention is characterized by a cooling water temperature detecting means for detecting the temperature of cooling water flowing through the absorber and the condenser.
Absorbing liquid temperature detecting means for detecting the temperature of the absorbing liquid regenerated by the regenerator, and flow rate control for controlling the flow rate adjusting means based on the detection information of the cooling water temperature detecting means and the absorbing liquid temperature detecting means. Means are provided.

[0008]

The operation of the above-described characteristic structure is as follows. The temperature of the absorption liquid regenerated by the regenerator changes as the operating state changes. That is, the change in the operating state is reflected in the temperature of the absorbing liquid regenerated by the regenerator. Based on the temperature of the cooling water that flows through the absorber and the condenser, which affects the absorption capacity of the absorbing liquid, the flow rate adjustment means is feedforward controlled and the regenerator that reflects changes in operating conditions is used. The flow rate adjusting means is feedback-controlled based on the temperature of the regenerated absorption liquid. The cooling water temperature detecting means and the absorbing liquid temperature detecting means can be provided, for example, so as to detect the temperature of the outer peripheral portion of the pipe forming the passage through which the cooling water and the absorbing liquid flow.

[0009]

Therefore, in addition to the feedforward control which has been conventionally executed, the feedback control in which the flow rate adjusting means is controlled based on the temperature of the absorbing liquid that reflects the fluctuation of the operating state is executed. It has become possible to adjust the concentration of the absorbing solution within an appropriate range regardless of fluctuations, and as a result, it is possible to reliably prevent the crystallization of the absorbent and the deterioration of the refrigerating capacity. Moreover, since the cooling water temperature detecting means and the absorbing liquid temperature detecting means can be provided very easily, the concentration of the absorbing liquid can be adjusted with a simple configuration.

[0010]

EXAMPLE An example in which the present invention is applied to a double-effect absorption refrigerator will be described below with reference to FIG. First,
The overall configuration of the double-effect absorption refrigerator will be described.

A vertical cylinder-shaped high temperature regenerator gas-liquid separator 2 is disposed above the high temperature regenerator 1 for heating the absorbing liquid by the burner B, and the peripheral portion of the high temperature regenerator gas-liquid separator 2 is arranged. A vertical low temperature regenerator 3 is disposed in the low temperature regenerator 3, a low temperature regenerator gas-liquid separator 4 is disposed above the low temperature regenerator 3, and a vertical absorber 5 is disposed around the low temperature regenerator 3. An evaporator 6 is arranged below the absorber 5 and a condenser 7 is arranged above the absorber 5. The absorber 5 and the evaporator 6 are arranged in a closed space formed in the peripheral portion of the low temperature regenerator 3, and the lower portion of the closed space communicates with the evaporator 6 and the absorber 5. A liquid reservoir 5a is provided.

The high temperature regenerator 1 is connected to the high temperature regenerator gas-liquid separator 2 through the ascending flow path 8 of the refrigerant vapor and the absorbing liquid, and the low temperature regenerator 3 is connected.
And the low temperature regenerator gas-liquid separator 4 are communicated with each other.
In order to supply a low-concentration absorbing liquid (hereinafter sometimes referred to as a dilute liquid) from the absorber 5 to the high temperature regenerator 1, the liquid reservoir 5a
The high temperature regenerator 1 and the high temperature regenerator 1 are connected to each other through a dilute liquid supply path 10 with a solution pump 9 interposed therebetween, and a medium concentration absorption liquid (hereinafter, also referred to as a medium liquid) is transferred from the high temperature regenerator 1 to the low temperature regenerator 3. In order to supply, the high-temperature regenerator gas-liquid separator 2 and the lower part of the low-temperature regenerator 3 are connected by the medium-liquid supply path 11, and the high-concentration absorbent (hereinafter referred to as concentrated liquid) In some cases, the low temperature regenerator gas-liquid separator 4 and the absorbent sprayer 12 above the absorber 5 are connected by a concentrated liquid supply path 13 in order to supply (also sometimes referred to as).

A high temperature heat exchanger 14 for heating the dilute liquid flowing through the dilute liquid supply passage 10 by the dilute liquid flowing through the dilute liquid supply passage 11.
And a low temperature heat exchanger 15 for heating the dilute liquid flowing through the dilute liquid supply passage 10 by the dilute liquid flowing through the dilute liquid supply passage 13.

The partition 16 for partitioning the high-temperature regenerator gas-liquid separator 2 and the low-temperature regenerator 3 is used to heat the absorption liquid in the low-temperature regenerator 3 with the refrigerant vapor in the high-temperature regenerator gas-liquid separator 2. It is formed on the heat transfer wall so that the refrigerant liquid generated by the condensation on the inner surface of the partition wall 16 flows down to the refrigerant liquid storage portion 2 a between the partition wall 16 and the inner cylinder 17.

Refrigerant liquid reservoir 2 of the high temperature regenerator gas liquid separator 2
a and the condenser 7 are connected by the refrigerant liquid supply passage 18, the low temperature regenerator gas-liquid separator 4 and the condenser 7 are connected by the refrigerant vapor supply passage 19, and the refrigerant liquid storage portion 7a below the condenser 7 is connected. And the refrigerant liquid spraying tool 20 of the evaporator 6 are connected by a refrigerant liquid supply passage 21.

The cooling water from the cooling water supply source 22 is absorbed by the absorber 5.
The cooling coil 23 and the cooling coil 24 are connected so that the cooling coil 23 inside the condenser 7 supplies the cooling coil 24 inside the condenser 7, and the cooling water supply path 25 is connected to them. The cooled coil 26 and the cooling target 27 are connected to each other by a cold water supply passage 28 having a pump so that the cold water from the cooled coil 26 in the evaporator 6 is supplied to the cooling target 27.

That is, the refrigerant vapor generated from the absorption liquid in the high temperature regenerator 1 is condensed in the high temperature regenerator gas-liquid separator 2, and the refrigerant liquid is supplied to the condenser 7 through the refrigerant liquid supply passage 18, and the low temperature regenerator. The refrigerant vapor generated from the absorbing liquid in 3 is supplied to the condenser 7 through the refrigerant vapor supply path 19, and the refrigerant vapor is condensed by the action of the cooling coil 24. Then, the refrigerant liquid stored in the refrigerant liquid storage portion 7a is sprayed into the evaporator 6 by the refrigerant liquid spraying tool 20, and the sprayed refrigerant liquid is evaporated by the action of the cooled coil 26, and the vaporization heat thereof causes The water flowing through the cooled coil 26 is cooled.

On the other hand, the absorption liquid from the low temperature regenerator gas-liquid separator 4 is sprayed into the absorber 5 by the absorption liquid spraying tool 12 so that the sprayed absorption liquid absorbs the refrigerant vapor generated in the evaporator 6. ,
The absorption liquid that has absorbed the refrigerant vapor is sequentially supplied to the high temperature regenerator 1, the high temperature regenerator gas-liquid separator 2, the low temperature regenerator 3, and the low temperature regenerator gas-liquid separator 4 to separate and regenerate the refrigerant, The regenerated absorbent is sprayed into the absorber 5 by the absorbent sprayer 12. That is, the absorption liquid is absorbed into the absorber 5, the liquid reservoir 5a, the dilute liquid supply path 10, the high temperature regenerator 1, the high temperature regenerator gas-liquid separator 2, the medium liquid supply path 11, the low temperature regenerator 3, and the low temperature regenerator gas. The liquid separator 4, the concentrated liquid supply path 13, and the absorber 5 are configured to circulate through a circulation path that circulates in this order.
Therefore, the dilute liquid supply passage 10, the medium liquid supply passage 11 and the concentrated liquid supply passage 13 function as an absorbing liquid circulation passage. The absorption heat generated by the absorption liquid absorbing the refrigerant vapor in the absorber 5 is
The cooling coil 23 is given to the water flowing through and taken out to the outside.

Next, various control configurations of the double-effect absorption refrigerator will be described. A rare liquid flow rate adjusting valve V ₁ for adjusting the flow rate of the rare liquid flowing through the rare liquid supply passage 10, a flow rate adjusting valve V ₂ for adjusting the input amount of the fuel such as natural gas supplied to the burner B, and the refrigerant liquid. A refrigerant liquid flow rate adjusting valve V ₃ for adjusting the flow rate of the refrigerant liquid flowing through the supply passage 21 is provided. That is, the refrigerant liquid flow rate adjusting valve V ₃ functions as the flow rate adjusting means F. Further, the temperature T of the cooling water flowing into the cooling coil 23
An absorber cooling water temperature sensor S ₁ for detecting ₁ and an intermediate liquid temperature sensor S ₂ for detecting the temperature T ₂ of the intermediate liquid flowing out from the high temperature regenerator gas-liquid separator ₂ are provided. That is, the absorber cooling water temperature sensor S ₁ functions as cooling water temperature detecting means Sw for detecting the temperature of the cooling water flowing through the absorber 5 and the condenser 7, and the medium liquid temperature sensor S ₂ is It functions as an absorbing liquid temperature detecting means Sy for detecting the temperature of the absorbing liquid regenerated by the high temperature regenerator 1. C in the figure indicates a control unit using a microcomputer. The control operation by the control unit C will be described below.

First, the control section C controls the flow rate adjusting valve V ₂ so that a predetermined input amount is obtained. Then, the opening degree of the dilute liquid flow rate adjusting valve V ₁ is controlled so that the flow rate of the absorbing liquid circulating in the circulation path becomes a flow rate corresponding to the predetermined input amount.

Next, the control operation for controlling the concentration of the absorbing liquid supplied to the absorber 5 will be described. The control unit C
Using the above, the calculation means 31, the adjustment opening calculation means 32, and the valve control means 33, which will be described later, are configured.

The temperature T of the cooling water flowing into the cooling coil 23
_{1. Between} the temperature T _{2 of the} medium liquid regenerated by the high temperature regenerator 1 and the concentration of the medium liquid regenerated by the high temperature regenerator 1,
Since there is a correlation, and the concentration width in which the middle liquid is concentrated in the low temperature regenerator 3 is constant, the temperature T _{1 of the} cooling water flowing into the cooling coil 23 and the middle liquid regenerated in the high temperature regenerator 1 are Between the temperature T ₂ and the concentration D of the concentrated liquid regenerated by the low temperature regenerator 3 (that is, the absorption liquid supplied to the absorber 5),
There is a correlation. Then, through experiments, it was found that there is a relationship as shown in FIG. 2 between the temperature T _{1 of the} cooling water, the temperature T _{2 of the} medium liquid, and the temperature of the concentration D of the concentrated liquid.

The calculating means 31 based on the relationship shown in FIG. 2, by a Chueki temperature T ₂ which absorber cooling water temperature sensor S ₁ coolant temperature detected T ₁ and the intermediate fluid temperature sensor S ₂ detects The concentrated liquid concentration D is calculated.

The adjustment opening calculating means 32 calculates the concentrated liquid concentration D calculated by the calculating means 31 and the preset target concentration D of the concentrated liquid.
Based on the deviation from p, the adjustment opening dW of the refrigerant liquid flow rate adjustment valve V ₃ for making the concentrated liquid concentration D the target concentration Dp is calculated. The target density Dp is appropriately set in the range of 58% to 62%, for example. Then, the valve control means 33 controls the opening W of the refrigerant liquid flow rate adjusting valve V ₃ so as to change by the adjustment opening dW calculated by the adjustment opening calculation means 32. That is, the calculation means 31, the adjustment opening degree calculation means 32, and the valve control means 33 function as a flow rate control means for controlling the refrigerant liquid flow rate adjustment valve V ₃ .

[Other Embodiments] Next, other embodiments will be listed. In the above-described embodiment, as the absorbent liquid temperature sensor Sy that detects the temperature of the absorbent liquid regenerated by the high temperature regenerator 1, the medium liquid that detects the temperature T ₂ of the medium liquid flowing out from the high temperature regenerator gas-liquid separator 2 Although the temperature sensor S ₂ is applied, since the temperature of the absorbing liquid regenerated by the high temperature regenerator 1 and the temperature of the high temperature regenerator 1 or the high temperature regenerator gas-liquid separator 2 have a correlation, As the sensor Sy, a temperature sensor that detects the temperature of the high temperature regenerator 1 or the high temperature regenerator gas-liquid separator 2 may be applied.

In the above embodiment, the temperature T _{1 of the} cooling water flowing into the cooling coil 23 is detected as the cooling water temperature detecting means Sw for detecting the temperature of the cooling water flowing through the absorber 5 and the condenser 7. has been illustrated for the case of applying the absorber cooling water temperature sensor S ₁ which, instead of this, the temperature gradient of the cooling water flowing through the absorber 5 and the condenser 7 is constant, the cooling water temperature As the detection means Sw, for example, a temperature sensor that detects the temperature of the cooling water flowing out from the cooling coil 23 may be applied.

[0027] To configure the flow control means, in the above embodiment, Chueki temperature T ₂ which absorber cooling water temperature sensor the cooling water temperature S ₁ is detected T ₁ and the intermediate fluid temperature sensor S ₂ detects
The concentration D of concentrated liquid is calculated from
The opening W of the refrigerant liquid flow rate adjusting valve V ₃ is controlled so that the target concentration Dp becomes, but instead of this, depending on various combinations of the cooling water temperature T ₁ and the medium liquid temperature T _2. Te, the target opening Wp of the refrigerant fluid flow regulating valve V ₃ is set in advance, Chueki temperature absorber cooling water temperature sensor the cooling water temperature S ₁ is detected T ₁ and the intermediate fluid temperature sensor S ₂ detects T ₂
Based on, it may be configured to control the refrigerant liquid flow regulating valve V ₃ so that the opening W of the refrigerant fluid flow regulating valve V ₃ is the target opening Wp.

Although the refrigerant liquid flow rate adjusting valve V ₃ is applied as the flow rate adjusting means F in the above embodiment, an inverter pump capable of adjusting the discharge amount may be applied instead of this.

The absorber 5, the evaporator 6 and the condenser 7 are
The high temperature regenerator gas / liquid separator 2, the low temperature regenerator 3 and the low temperature regenerator gas / liquid separator 4 may be separately installed.

The refrigerant and the absorbing liquid can be appropriately selected from known ones.

In the above embodiment, the case where the present invention is applied to the double-effect absorption refrigerator is illustrated, but it is also possible to apply to the single-effect absorption refrigerator.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the configuration of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a block diagram of a double-effect absorption refrigerator.

FIG. 2 is a diagram showing the relationship between the concentration of concentrated liquid, the temperature of medium liquid, and the temperature of cooling water.

[Explanation of symbols]

 1 Regenerator 5 Absorber 5a Liquid Reservoir 6 Evaporator 7 Condenser 10, 11, 13 Absorbing liquid circulation path 21 Refrigerant liquid supply path 31, 32, 33 Flow control means F Flow rate adjusting means Sw Cooling water temperature detecting means Sy Absorption Liquid temperature detection means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideki Tani, 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka, Osaka Gas Co., Ltd. (72) Toshihiro Sato, Fukuzumi-cho, Nakagawa-ku, Nagoya 26 Rinnai Co., Ltd.

Claims (1)

[Claims] 1. An evaporator (6) for evaporating a refrigerant liquid, an absorber (5) for absorbing a refrigerant vapor generated in the evaporator (6) into an absorbing liquid, the evaporator (6) and the absorption. A liquid reservoir (5a) communicating with the container (6) and a regenerator (1) for regenerating the absorption liquid diluted with the refrigerant are provided, and the liquid reservoir (5a) and the regenerator (1) are provided. And the absorber (5) is an absorption liquid circulation path (10), (11), (13).
And a condenser (7) and the evaporator (6) are connected by a refrigerant liquid supply path (21) having a flow rate adjusting means (F) interposed therebetween. Cooling water temperature detecting means (Sw) for detecting the temperature of the cooling water flowing through the absorber (5) and the condenser (7).
An absorbing liquid temperature detecting means (Sy) for detecting the temperature of the absorbing liquid regenerated by the regenerator (1), the cooling water temperature detecting means (Sw) and the absorbing liquid temperature detecting means (Sy).
An absorption chiller provided with flow rate control means (31), (32), (33) for controlling the flow rate adjusting means (F) based on the detection information of the above.