JP2787112B2 - Control method of air volume for combustion of absorption chiller / heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the amount of combustion air supplied to heat a refrigerant solution in an absorption chiller / heater.

[0002]

2. Description of the Related Art In a conventional double effect absorption chiller / heater, the amount of heat input to a high-temperature regenerator is controlled according to the cooling load of the chiller / heater, and the cooling load is the temperature of the chilled water outlet heat exchanged by the evaporator. Is detected by In other words, the amount of heat input to the high-temperature regenerator is controlled in proportion to the chilled water outlet temperature.If the chilled water outlet temperature decreases, it is determined that the cooling load is small, and the amount of heat input is reduced. It is determined that the cooling load has increased, and the heat input is increased.

As shown in FIG. 2, the amount of heat input to the high-temperature regenerator is controlled by a motor-operated valve or a solenoid valve 12 to control the flow rate of gas or kerosene or the like supplied to the high-temperature regenerator 1. The flow rate of the combustion air according to the flow rate is obtained by controlling the flow rate of the combustion air in proportion to the fuel flow rate by an adjusting valve or an equalizing proportional valve 20 linked to the electric valve or the solenoid valve 12.

[0004]

In the above-mentioned control method, it is difficult to optimally set the fuel flow rate and the air flow rate in a wide range of the heat input amount, and the adjusting mechanism becomes complicated and the control device becomes expensive. There's a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a simple, inexpensive, and stable method of controlling the amount of combustion air in an absorption chiller / heater in accordance with the fuel flow. The purpose is to provide.

[0006]

In order to achieve the above object, a method for controlling the amount of combustion air of an absorption chiller / heater according to the present invention is directed to a regeneration method for heating a refrigerant solution to generate a refrigerant vapor and a concentrated solution. , A separator for separating the vapor and the concentrated solution , a condenser for condensing the separated refrigerant vapor, an evaporator for evaporating the condensed refrigerant, and a concentrated solution for separating the evaporated refrigerant by the separator Is cooled while being sent through the heat exchanger
A method for controlling the amount of combustion air of an absorption chiller / heater provided with an absorber for absorbing the concentrated solution, wherein the flow rate of fuel used for heating in the regenerator is proportional to the load of the absorption chiller / heater. On the other hand, the combustion air flow rate of the fuel is controlled in a stepwise manner for each fixed range of the fuel flow rate as a constant value of the air quantity necessary for complete combustion at the maximum fuel flow rate in the range. It is characterized by the following.

[0007] The fixed range of the fuel flow rate is preferably divided every 20% or less of the fuel flow rate with respect to the full load of the absorption chiller / heater.

[0008]

In the method for controlling the amount of combustion air of the absorption chiller / heater according to the present invention, the air flow rate is changed stepwise for each fixed range of the fuel flow rate, so that the air flow rate can be controlled by a simple mechanism. In addition, when a certain range of the fuel flow rate is divided by 20% of the fuel flow rate with respect to the preload, the fuel burns in excess of air in most cases. However, it has been experimentally confirmed that there is no problem in the flammability with the excess air. .

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of an absorption chiller / heater to which a method for controlling the amount of combustion air of an absorption chiller / heater according to the present invention is applied.

This absorption chiller / heater is of a double effect type, and as a refrigerant circulation system, as shown in FIG.
The separator 2, the low-temperature regenerator 3, the condenser 4, the evaporator 5, the absorber 6, the solution circulation pump 7, the high-temperature side heat exchanger 8, and the low-temperature side heat exchanger 9 are connected by pipes. 5, a chilled water temperature sensor 10 for detecting an outlet temperature of chilled water taken out from the chilled water heat transfer coil 5, a fuel control valve 12 for supplying fuel to the high temperature regenerator 1, and two valves SV for supplying combustion air.
1, SV2, and a controller 11 for controlling each of these device elements. The double effect absorption chiller / heater described in the section of the prior art has the same configuration as that shown in FIG. 1 except for a fuel and combustion air supply system.

The high-temperature regenerator 1 heats the dilute solution of the refrigerant to generate a high-temperature refrigerant vapor and an intermediate concentrated solution, and the separator 2 generates a high-temperature refrigerant vapor sent from the high-temperature regenerator 1 and the intermediate concentrated solution. Separate from solution. The low-temperature regenerator 3 condenses the refrigerant vapor by heat exchange between the intermediate concentrated solution separated by the separator 2 and cooled by the high-temperature heat exchanger 8 and the high-temperature refrigerant vapor taken in from the separator 2. In addition to liquid, a refrigerant vapor is generated from the intermediate concentrated solution to form a concentrated solution. Condenser 4
Cools the refrigerant liquid sent from the low-temperature regenerator 3 and cools and condenses the refrigerant vapor from the low-temperature regenerator 3.

The evaporator 5 disperses the refrigerant liquid sent from the condenser 4 to the chilled water heat transfer coil to evaporate it. At this time, the cooling water supplied to the heat transfer coil exchanges heat with the evaporated refrigerant. Cooled into cold water, which is supplied for cooling. The absorber 6 introduces a concentrated solution concentrated in the low-temperature regenerator 3 and cooled in the low-temperature side heat exchanger 9 and spraying the concentrated solution to absorb the refrigerant vapor evaporated in the evaporator 5 to make a diluted solution. .
The diluted solution is returned to the high-temperature regenerator 1 via the low-temperature heat exchanger 9 and the high-temperature heat exchanger 8 by the solution circulation pump 7.

The cooling load of the absorption chiller / heater is obtained from the temperature of the chilled water that has been cooled by exchanging heat with the refrigerant vapor in the evaporator 5 and exited from the heat transfer coil outlet (the outlet temperature of the chilled water). The amount of heat input to heat the diluted solution of the refrigerant in the high-temperature regenerator 1 corresponding to the cooling load, that is, the amount of fuel and the amount of combustion air supplied to the high-temperature regenerator 1 detects the outlet temperature of the cold water. Is controlled by the cold water temperature sensor 10. The use of the cold water temperature sensor is the same as the conventional one.

In this absorption chiller / heater, a high-temperature regenerator 1
The flow rate of the gas or the fuel such as kerosene supplied to the fuel cell is controlled by a fuel control valve 12 such as a proportional electric valve or a proportional solenoid valve so that the flow rate increases or decreases according to the rise or fall of the outlet temperature of the cold water discharged from the evaporator 5. Done. On the other hand, the flow rate control of the combustion air is performed by two types of air control valves having different diameters provided on the blower discharge side for supplying the air. These two types of air control valves SV1 and SV2 are used in combinations as shown in Table 2.

Table 1 shows the ratio of the opening diameters of the two types of air control valves SV1 and SV2 when they are turned on and off.

Table 1 (%) ON-OFF of air control valve SV1 SV2 Air flow Load amount ON (60) ON (40) 60 + 40 = 100 100 to 80 ON (60) OFF (20) 60 + 20 = 80 80-60 OFF (20) ON (40) 20 + 40 = 60 60-40 OFF (20) OFF (20) 20 + 20 = 40 40- Air to fuel flow when the load of absorption chiller / heater is 100% The flow rate is expressed as 100%. The air flow rate is controlled in four stages by changing by 20% with respect to the fuel flow rate changing in proportion to the load change. That is, when both SV1 and SV2 are ON, the flow rate is 100%,
When SV1 is ON and SV2 is OFF, the flow rate is 80%. When SV1 is OFF and SV2 is ON, the flow rate is 6%.
0%, and when both SV1 and SV2 are OFF, the flow rate is 40%.

As shown in Table 1, the amount of fuel supplied to the high-temperature regenerator is controlled in proportion to the load. on the other hand,
The amount of combustion air is as follows: (1) When the load amount is in the range of 100 to 80%, both SV1 and SV2 are turned on and the air flow rate is
0%, (2) When the load is less than 80 to 60%, SV1 is turned on and SV2 is turned off, the air flow rate is kept at 80%, and (3) the load is less than 60. 4
In the range of 0%, SV1 is turned off, SV2 is turned on, the air flow rate is kept constant at 60%, and (4) the load amount is 40%.
In the range below, both SV1 and SV2 are turned off,
The air flow rate is controlled to be constant at 40%.

In the method of controlling the air supply amount by the two kinds of control valves as described above, the air flow rate is determined by the preset solenoid valve diameter or the opening degree of the butterfly valve. Less complicated setting adjustment,
Further, since the control mechanism is stepwise control, the control mechanism is simple, and the control amount is not disturbed by disturbance, and a controllable apparatus can be provided at low cost.

At a certain load amount, for example, 80% load, an excess amount of air is burned when the amount of air is 100% with respect to 80% of fuel. However, such an increase in excess air coefficient causes a problem in flammability. The test confirmed that none were present.

Also, unlike the double effect absorption chiller / heater having a high temperature regenerator and a low temperature regenerator as described above, a single effect absorption chiller / heater having only one regenerator, that is, by heating a refrigerant solution. a regenerator for generating the refrigerant vapor and the concentrated solution, and separator that separates the refrigerant vapor and the concentrated solution, a condenser for condensing the separated coolant vapor, an evaporator for evaporating the condensed refrigerant, evaporated The above-described method for controlling the amount of combustion air is also applied to an absorption chiller / heater including an absorber that absorbs the concentrated refrigerant into a concentrated solution that is cooled while the concentrated solution is sent through the heat exchanger. As with the dual-effect absorption chiller / heater, there is less complexity in setting and adjusting the amount of air for combustion, and the control mechanism is simple. available.

[0021]

According to the present invention, the method for controlling the combustion air amount of the absorption chiller / heater controls the fuel flow rate in proportion to the load of the absorption chiller / heater. Since the air flow rate is changed step by step in a certain range of the fuel flow rate, the air flow rate can be controlled with a simple mechanism. Can control air.

[Brief description of the drawings]

FIG. 1 is a diagram showing the configuration of an apparatus to which a method for controlling the amount of combustion air of an absorption chiller / heater according to the present invention is applied.

FIG. 2 is a view showing a control valve for adjusting a combustion air amount according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High temperature regenerator 2 Separator 3 Low temperature regenerator 4 Condenser 5 Evaporator 6 Absorber 7 Solution circulation pump 8 High temperature heat exchanger 9 Low temperature heat exchanger 10 Cold water temperature sensor 11 Controller 12 Fuel control valve SV1, SV2 Air control valve

Claims (2)

(57) [Claims] 1. A regenerator for heating a refrigerant solution to generate a refrigerant vapor and a concentrated solution , a separator for separating the refrigerant vapor and the concentrated solution, and a condenser for condensing the separated refrigerant vapor And an evaporator for evaporating the condensed refrigerant,
A heat exchanger for cooling the concentrated solution separated by the separator,
A method for controlling the amount of combustion air in an absorption chiller-heater, comprising: an absorber for absorbing the refrigerant evaporated in the evaporator into the concentrated solution sent from the heat exchanger. The flow rate is controlled so as to be supplied in proportion to the load of the absorption chiller / heater. On the other hand, the air flow rate supplied for combustion of the fuel is set to the maximum of the fixed range for each fixed range of the fuel flow rate. A method of controlling the amount of air for combustion of an absorption chiller / heater, wherein the amount of air required for complete combustion at the time of fuel flow is controlled in a stepwise manner. 2. The air flow rate for combustion of an absorption chiller / heater according to claim 1, wherein the predetermined range of the fuel flow rate is divided for every 20% or less of the fuel flow rate with respect to the full load of the absorption chiller / heater. Control method.