JP2002357372A - Cogeneration type absorption refrigerating machine and controlling method of operation thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize the exhaust heat of an engine at the maximum according to a state of operation, as a heating source for heating a dilute solution to be made a concentrated one, and thereby to minimize the consumption of fuel. SOLUTION: An operation control map having an operation area C wherein the dilute solution is heated by using only the exhaust heat of an engine, an operation area B wherein the dilute solution is heated by using jointly the burner heating by a burner set at the lower limit of a burner load control range and the exhaust heat of the engine, an operation area A wherein the solution is heated by using jointly the burner heating varying within the burner load control range and the exhaust heat of the engine and operation areas E and F wherein the solution is heated by using only the burner heating varying within the burner load control range, is formed in a cogeneration type absorption refrigerating machine, and a control part selecting the operation area corresponding to detected values of a cooling-heating load and an engine load from the operation control map is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cogeneration type absorption refrigerator capable of simultaneously performing power generation and cooling / heating, and in particular, operates efficiently by effectively utilizing exhaust heat of an engine driving the generator. And a control method thereof.

[0002]

2. Description of the Related Art A cogeneration type absorption refrigerator is a device capable of simultaneously performing power generation by an engine driven generator and cooling and heating by an absorption refrigerator, and uses exhaust heat of an engine as a heating source of the absorption refrigerator. This can reduce the fuel consumption required to heat a dilute solution of the absorbing solution (generally lithium bromide) to a concentrated solution. For this reason, the cogeneration type absorption refrigerator has an advantage that energy can be saved with high efficiency as compared with a normal absorption refrigerator.

An absorption refrigerator is a refrigerator using water as a refrigerant, a lithium bromide solution as an absorbent, and gas fuel, oil fuel or steam as a heating energy source. This absorption refrigerator includes an evaporator, an absorber, a regenerator, and a condenser as main members, and the inside of the evaporator and the absorber is maintained at a high vacuum (absolute pressure is 6 to 7 mmHg). .

[0004] In the evaporator, the liquid refrigerant (water) sent by the refrigerant pump is sprayed toward an evaporator tube through which cold water (for example, 12 ° C) flows, so that the liquid refrigerant is heated and refrigerant vapor ( Gas). That is, since the evaporator is a high-vacuum vessel, liquid water (refrigerant) boils at about 4 to 6 ° C. and evaporates, and thus, for example, cold water of 12 ° C. can be used as a heat source water. You can do it.

[0005] The temperature of the cold water flowing in the evaporator tube is reduced by the amount of latent heat of evaporation given to the liquid refrigerant (water) (for example, 7 ° C).
And exits the evaporator. The cold water whose temperature has been lowered (for example, to 7 ° C.) is sent to a cooling device of a building or the like (cooling load), and is used for cooling as a cooling heat source that exchanges heat with indoor air to cool. The cold water used for cooling rises in temperature (for example, to 12 ° C.) and flows into the evaporator tube of the evaporator again.

In the absorber, the refrigerant vapor generated in the evaporator is absorbed by the lithium bromide solution. The lithium bromide solution (hereinafter, referred to as a “lithium bromide dilute solution”) that has absorbed water and has a low concentration is collected at the bottom of the absorber. In this absorber, the latent heat of condensation when the refrigerant vapor is absorbed by the lithium bromide solution and changes from gas (water vapor) to liquid (water), and when the concentration of the lithium bromide solution becomes thin due to the absorption of moisture. Since heat of dilution is generated, the heat is removed by cooling water (circulated in a different system from the above-mentioned “cold water”). Note that the lithium bromide solution is a substance that is rich in hygroscopicity and suitable for absorbing the refrigerant vapor, since the water vapor partial pressure is lower than the saturated vapor of water.

In the regenerator, the dilute lithium bromide solution sent from the absorber is heated by a burner or the like. For this reason,
A part of the refrigerant in the lithium bromide dilute solution is evaporated and vaporized, and the solution becomes a concentrated lithium bromide solution (hereinafter, referred to as a “lithium bromide concentrated solution”). The lithium bromide concentrated solution whose concentration has been increased to the original state in this way is sent to the absorber and absorbs the refrigerant vapor again. On the other hand, the evaporated refrigerant vapor is sent to the condenser.

In the actual absorption chiller, a double effect absorption chiller in which regenerators are arranged in two stages is employed for the purpose of increasing thermal efficiency and reducing heating energy.
In this double-effect absorption refrigerator, a high-pressure regenerator that heats a dilute lithium bromide solution by burning supplied fuel or by introducing high-temperature steam, A low-pressure regenerator for heating the lithium bromide dilute solution using the high-temperature refrigerant vapor generated in the reactor as a heating source.

[0009] In the condenser, the refrigerant vapor sent from the regenerator is condensed and liquefied by being cooled by cooling water. The water condensed in this condenser is supplied again to the evaporator as a liquid refrigerant (water).

Thus, in the absorption refrigerator, the refrigerant (water) changes from water to water vapor to water (phase change), and the lithium bromide solution changes from a concentrated solution to a dilute solution to a concentrated solution. (Change in density). In the process of the above-described phase change (refrigerant) and concentration change (lithium bromide solution), the absorption refrigerator produces cold water by the latent heat of evaporation of water, and absorbs water vapor by the absorption capacity of the lithium bromide solution. Is repeatedly performed in a high vacuum closed system.

In such an absorption refrigerator, the amount of fuel or steam supplied to the high-pressure regenerator is increased to increase the amount of heating, and the concentration of the lithium bromide solution is increased, so that the cold water flowing out of the evaporator is increased. The temperature can be lowered. Conversely, by reducing the amount of fuel and steam supplied to the high-pressure regenerator to reduce the amount of heating and decreasing the concentration of the lithium bromide solution, the temperature of cold water exiting the evaporator can be increased. . Thus, by adjusting the concentration of the lithium bromide solution, the temperature of the cold water is controlled to maintain the temperature of the cold water flowing out of the evaporator at a set temperature (for example, 7 ° C.).

In the cogeneration type absorption refrigerator, an engine-driven generator is installed together with the absorption refrigerator described above, and the exhaust heat of the engine driving the generator is used as a heating source for the high-pressure regenerator. In addition, the amount of fuel used in the high-pressure regenerator can be saved.

[0013]

By the way, in the above-mentioned conventional cogeneration type absorption refrigerator, the exhaust heat of the engine is used more effectively according to the cooling / heating load and the operating condition of the generator (engine). Is desired. That is, based on the operating condition of the engine and the cooling and heating capacity required of the absorption refrigerator, an operation method that can use the exhaust heat of the engine most effectively is selected, and the fuel consumption required for heating the dilute solution is further reduced to achieve a high level. It is desired to improve efficiency.

The present invention has been made in view of the above circumstances, and as a heating source for heating a dilute solution to make a concentrated solution, the exhaust heat of the engine is used as efficiently as possible according to the operating conditions, and the fuel is used. It is an object of the present invention to provide a cogeneration type absorption chiller capable of minimizing the consumption of water and a control method thereof.

[0015]

The present invention has the following features to attain the object mentioned above. The cogeneration type absorption refrigerator according to claim 1, wherein the lean gas discharged from the absorber is formed by absorbing and dissolving a refrigerant gas evaporated by an evaporator into a high-concentration solution in the absorber, and a power generator driven by an engine. An absorption refrigerator that regenerates the solution as a high-temperature, high-concentration solution by heating the solution and returns the high-concentration solution to the absorber,
In a cogeneration absorption refrigerator using the exhaust heat of the engine as a heating source of the dilute solution, a first operating region in which the dilute solution is heated using only the engine exhaust heat and a lower limit of a burner load control range. A second operating region in which the diluted solution is heated by using the burner heating by the set burner and the engine exhaust heat in combination with the burner heating and the engine exhaust heat that change within a burner load control range. An operation control map including a third operation region for heating the dilute solution and a fourth operation region for heating the dilute solution using only the burner heating that changes within the burner load control range is formed. A control unit is provided for selecting an operation area corresponding to the detected values of the cooling / heating load and the engine load from the operation control map.

According to such a cogeneration type absorption refrigerator, it is possible to uniquely select an optimal operation region corresponding to the engine load and the cooling / heating load based on the operation control map formed in the control unit. The actually selected operation area can be easily displayed on a monitor or the like so that it can be seen at a glance.

In the cogeneration type absorption refrigerator of the first aspect, the first operation range includes a lower limit of operation of the absorption refrigerator, a cooling / heating capacity line of engine exhaust heat that increases with an engine load, and an engine load. The second area is set in an area surrounded by a 100% line, and the second area is an operation lower limit value of the engine load, an operation lower limit value of the absorption refrigerator, and a cooling / heating capacity of engine exhaust heat that increases with the engine load. And a line surrounded by a line of 100% engine load and a lower limit of the burner load control range. The third region is a line of the lower limit of operation of the engine load and the line of 100% engine load. A lower limit value of the burner load control range, and a region surrounded by a line of 100% cooling / heating load, wherein the fourth region is an operation lower limit value of the engine load, Operating lower limit value of the absorption refrigerator,
An operation control map set in a region surrounded by the line with the engine load of 0% and the line with the cooling and heating load of 100% is preferable, and thereby, the operation control that makes the most effective use of the engine exhaust heat can be performed.

In the cogeneration type absorption refrigerator according to claim 1 or 2, the cooling / heating load is obtained by calculating a ratio of an actual inlet / outlet temperature difference to a chilled water inlet / outlet temperature difference at rated time, and the engine load is: It is preferable to adopt a value obtained by calculating the ratio of the power demand amount to the rated power generation capacity, thereby easily and accurately grasping the operation status of the cogeneration absorption refrigerator and selecting an optimal operation region. be able to. In particular, since the engine load is calculated from the actual power demand, the engine side and the control system are directly connected to enable integrated operation control.

In the cogeneration type absorption chiller according to any one of claims 1 to 3, it is preferable that a load change rate of the engine is detected, and combustion control of the burner is performed based on the load change rate. As a result, it is possible to minimize fluctuations in the cooling / heating capacity due to changes in the engine load.

In the cogeneration type absorption refrigerator according to any one of claims 1 to 4, in the first region, when the supply capacity is larger than the cooling / heating load, a refrigerant is introduced into the solution line to reduce the solution concentration. It is preferable to perform control, whereby an operation according to the cooling and heating load can be performed during operation using only engine exhaust heat. In this case, the concentration of the solution may be adjusted by operating a stabilizer valve provided in a pipe connecting the evaporator and the absorber, by introducing water of the refrigerant into the solution line.

In the cogeneration type absorption refrigerator according to any one of claims 1 to 5, in the second region, when the supply capacity is larger than the cooling / heating load, a refrigerant is introduced into the solution line to reduce the solution concentration. It is preferable to control the operation, whereby the operation in the burner turndown region can be stabilized. In this case, the concentration of the solution may be adjusted by operating a stabilizer valve provided in a pipe connecting the evaporator and the absorber, by introducing water of the refrigerant into the solution line.

In the cogeneration absorption refrigerator according to any one of the first to seventh aspects, when the supply capacity is larger than the cooling / heating load in the second region, a predetermined hysteresis is provided for the chilled water outlet temperature. It is preferable to turn on / off the burner, so that the number of times the burner starts and stops can be reduced.

A method for controlling a cogeneration type absorption refrigerator according to claim 9 includes: a power generator that uses an engine as a drive source;
The refrigerant gas evaporated by the evaporator is absorbed and dissolved in the solution in the absorber, and the diluted solution exiting the absorber is heated to be regenerated as a high-temperature high-concentration solution, and the high-concentration solution is returned to the absorber. An operation control method of a cogeneration type absorption refrigerator including an absorption refrigerator and using exhaust heat of the engine as a heating source of the dilute solution, wherein a first method of heating the dilute solution using only engine exhaust heat is provided. Operating area and
A second operating region in which the dilute solution is heated by using both the burner heating by the burner set to the lower limit of the burner load control range and the engine exhaust heat; and a burner heating that changes within the burner load control range and the engine. A third operation region for heating the dilute solution in combination with exhaust heat, and a fourth operation region for heating the dilute solution using only burner heating that changes within a burner load control range. An operation control map is formed, and operation control is performed by selecting an operation region corresponding to the detected values of the cooling / heating load and the engine load from the operation control map.

According to the operation control method of the cogeneration type absorption refrigerator, the optimum operation region corresponding to the engine load and the cooling / heating load can be uniquely selected and determined based on the operation control map. High-efficiency operation using waste heat effectively can be easily performed.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a cogeneration type absorption refrigerator according to the present invention and an operation control method thereof will be described below with reference to the drawings. The overall configuration of a cogeneration absorption refrigerator according to the present invention is shown in the system diagram of FIG. The cogeneration type absorption refrigerator has an absorption refrigerator ARM and a gas engine unit GE for driving a generator (not shown).

The gas engine section GE is an internal combustion engine for driving a generator (not shown) according to the amount of power demand. In the figure, reference numeral 1 denotes a gas engine, 2 denotes a jacket water flow path, and 3 denotes a jacket water flow path. A heat-exchanging heat exchanger (so-called radiator), 4 is a three-way valve, 5 is an exhaust gas discharge line, 6 is a silencer, and 7 is a gas engine control unit. The gas engine 1 is operated under the control of the gas engine control unit 7 using gas fuel such as city gas as fuel. The gas engine control unit 7 not only controls the operation / stop of the gas engine 1, but also controls the output of the gas engine 1 by adjusting the fuel supply amount and the like according to the load on the generator side that changes according to the power demand amount. It has the function to do.

The jacket water flow path 2 is a flow path for circulating jacket water (engine cooling water) in order to cool the gas engine 1 and maintain it within a predetermined operating temperature range. A heat-radiating heat exchanger 3 and a jacket water heat exchanger 31 on the absorption refrigerator ARM described later are connected to the jacket water flow path 2, and the flow paths can be selectively switched by the jacket water three-way valves 4 and 34, respectively. It has become. The main purpose of the heat-dissipating heat exchanger 3 is to cool the jacket water, while the main purpose of the jacket water heat exchanger 31 is to utilize the exhaust heat of the gas engine 1. Note that the illustrated heat-radiating heat exchanger 3 employs a water-cooled type in which jacket water is cooled by exchanging heat with cooling water W2 described later, but may be an air-cooled type in which cooling is performed by outside air.

The exhaust gas discharge line 5 is a pipe for discharging high-temperature exhaust gas generated by burning gaseous fuel from a chimney or the like to the atmosphere. A muffler 6 is provided in the middle of the pipe. The exhaust gas discharge line 5 can effectively utilize the exhaust heat of the gas engine 1 by introducing exhaust gas into the high-pressure regenerator 40 on the absorption refrigerator ARM side described later.

In the absorption refrigerator ARM, the evaporator 10 and the absorber 20 are formed in the same shell (high vacuum vessel). An evaporator tube 11 is disposed in the evaporator 10, and the tube 11 is supplied with cold water W1 via a cold water inlet line L1. The cold water W1 flowing through the evaporator tube 11 is discharged to the outside via the cold water outlet line L2. Further, the refrigerant (water) pumped by the refrigerant pump P1 from the bottom of the evaporator 10 via the refrigerant line L11 indicated by the broken line is sprayed from the upper part of the evaporator 10 toward the evaporator tube 11. The refrigerant thus sprayed is
The latent heat of vaporization is taken from the cold water W1 flowing through the evaporator tube 11 to evaporate and become refrigerant vapor. This refrigerant vapor flows into the absorber 20 through the gas-liquid separator 12 provided between the evaporator 10 and the absorber 20.

The above-mentioned cold water W1 enters the evaporator 10 at a temperature of, for example, 12 ° C. (cold water inlet temperature Ti), is cooled by the evaporator tube 11, and is then discharged from the evaporator 10 to the e.g.
(Cooled water outlet temperature To) and discharged. The 7 ° C. cold water W1 supplied from the cold water outlet line L2 is used, for example, for cooling a building or for a process in a factory. The cold water W1 provided for cooling at a cooling load such as a building cooling rises in temperature by exchanging heat with indoor air,
For example, when the cold water inlet temperature reaches 12 ° C., the evaporator 10
Inflows into

On the other hand, an absorber tube 2 is provided in the absorber 20.
1 is arranged. Cooling water W2 is supplied to the absorber tube 21 via a cooling water line L3. Then, the concentrated solution of lithium bromide (absorbing solution) pumped through the solution line L21 is sprayed toward the absorber tube 21. For this reason, the sprayed lithium bromide concentrated solution absorbs the refrigerant vapor flowing into the absorber 20 through the gas-liquid separator 12, so that the concentration of the solution is reduced.
The diluted lithium bromide solution having a reduced concentration is collected at the bottom of the absorber 20. The heat generated in the absorber 20 is generated by the cooling water W2 flowing through the absorber tube 21.
Cooling.

The dilute lithium bromide solution collected at the bottom of the absorber 20 is pumped by a solution pump P2, and is supplied with a low-temperature heat exchanger 30, a solution line L22, and a jacket water heat exchanger 3.
1, is supplied to the high-pressure regenerator 40 via the high-temperature heat exchanger 32, the solution line L23 and the exhaust gas heat recovery heat exchanger 33.

The high-pressure regenerator 40 accommodates a furnace tube and a heat transfer tube in a body, and is equipped with a burner 41 and an exhaust gas line 42 as a heating source. One burner 41 heats the lithium bromide dilute solution with heat of a combustion gas or the like generated by burning fuel gas (burner fuel) supplied through a fuel control valve 43 provided in a gas line L31. Is what you do. The other exhaust gas line 42 introduces the high-temperature exhaust gas (exhaust heat) supplied from the above-described exhaust gas discharge line 5 of the gas engine unit GE into the high-pressure regenerator 40, and in the process of passing this exhaust gas. This is for heating a dilute solution of lithium bromide. Since the exhaust gas 42 is branched from the exhaust gas discharge line 5 directly led to the chimney 45 by the exhaust gas three-way valve 44, the introduction of the exhaust gas to the high-pressure regenerator 40 can be selected as necessary. High pressure regenerator 40
The exhaust gas flowing out of the exhaust gas is discharged from the chimney 45 to the atmosphere after the exhaust heat is recovered by heating the dilute lithium bromide solution in the exhaust gas heat recovery heat exchanger 33. The burner 41
The heating using the exhaust gas line 42 using the heat from the engine and the exhaust gas line 42 using the exhaust heat from the engine can be used alone or in combination of both depending on the operation control map of the control unit 70 described later.

The lithium bromide dilute solution supplied to the high-pressure regenerator 40 is heated by the above-mentioned heating source, whereby a part of the refrigerant evaporates and becomes a high-concentration solution. This lithium bromide solution is supplied to a solution line L24, a high-temperature heat exchanger 32,
The concentration further increases through the low-temperature heat exchanger 30 and is supplied again to the absorber 20 as a lithium bromide concentrated solution.

On the other hand, the refrigerant vapor evaporated in the high pressure regenerator 40 is supplied to a low pressure regenerator tube (not shown) of the low pressure regenerator 50 and further supplied to a condenser 60. Note that the low-pressure regenerator 50 and the condenser 60 are configured in the same shell. In the low-pressure regenerator 50, the solution line L2
The dilute solution of lithium bromide branched from the solution line L22 through 5 is sprayed toward the low-pressure regenerator tube.
This lithium bromide dilute solution is heated by the low-pressure regenerator tube, and a part of the refrigerant evaporates to become a high-concentration lithium bromide concentrated solution. After being sent to the heat exchanger 32, it is again supplied to the absorber 20 as a lithium bromide concentrated solution.

The condenser 60 has a cooling water line L4
A condenser tube 61 to which the cooling water W2 is supplied is disposed. In the condenser 60, the refrigerant vapor evaporated in the high-pressure regenerator 40 and introduced into the low-pressure regenerator 50 and the refrigerant vapor evaporated in the low-pressure regenerator 50 and flowing into the condenser 60 are combined with the condenser 60. Cooled and condensed in the tube 61 to become a refrigerant (water). This refrigerant R is sent to the evaporator 10 via the refrigerant line L14 due to gravity and a pressure difference.
After the refrigerant is collected at the bottom of the evaporator 10, the refrigerant is again sprayed toward the evaporator tube 11 via the refrigerant line L11 by the refrigerant pump P1.

Further, in the absorption refrigerator ARM, the evaporator 10
The heating operation is performed by flowing hot water for heating through the cold water system (evaporator tube 11) and introducing the high-temperature refrigerant vapor generated by the high-pressure generator 40 into the evaporator 10 via a path (not shown). Can be. The high-temperature refrigerant vapor introduced into the evaporator 10 is directly sprayed toward the evaporator tube 11, and the outlet temperature can be made higher than the inlet temperature by heating the hot water flowing inside. The refrigerant (water) condensed by this heating falls to the bottom of the condenser 10 and is supplied to the solution pump P2.
By the operation of, the fluid flows into the absorber 20 through the stabilizer electromagnetic valve 13 in the open state. The condensed water of the refrigerant flowing into the absorber 20 is mixed with the lithium bromide solution to become a dilute solution,
Thereafter, the solution is supplied to the high-pressure regenerator 40 through the solution line L22, the low-temperature heat exchanger 30, the jacket water heat exchanger 31, the high-temperature heat exchanger 32, and the exhaust gas heat recovery heat exchanger 33.

The lithium bromide dilute solution supplied to the high-pressure regenerator 40 is reheated by a burner 41 and an exhaust gas line 42. The high-temperature refrigerant vapor evaporated in this way is supplied to the evaporator 1
By supplying to 0, the water of the refrigerant flows through the same path and repeats the state change, so that the heating operation can be continued. In addition, even during such a heating operation, the exhaust heat of the gas engine 1 can be effectively used in the jacket water heat exchanger 31, the high temperature regenerator 40, and the exhaust gas heat recovery heat exchanger 33.

The control unit 70 of the cogeneration absorption chiller having the above-described configuration has an operation control map as shown in FIG. The operation control map is provided with four operation regions, and selects an operation region corresponding to a value obtained by detecting a cooling / heating load on the vertical axis and an engine load on the horizontal axis. The first operation region is for heating a dilute solution of lithium bromide using only the exhaust heat of the gas engine 1, and is a region C in FIG.
This operation region C is defined as an operation lower limit value of the absorption refrigerator ARM,
It is set in a region surrounded by the cooling / heating capacity line of the engine exhaust heat that increases with the engine load and the line of the engine load of 100%.

The second operation region is for heating the dilute solution of lithium bromide by using both the burner heating by the burner 41 set at the lower limit of the burner load control range and the engine exhaust heat. It is an area B. The operation region B includes an operation lower limit of the engine load, an operation lower limit of the absorption refrigerator ARM, a cooling / heating capacity line of the engine exhaust heat increasing with the engine load, a line of the engine load of 100%, and a burner load control range. Is set in a region surrounded by the lower limit value of.

The third operation region is for heating the dilute solution of lithium bromide by using both the burner heating and the engine exhaust heat that change within the burner load control range, and corresponds to region A in FIG. is there. The area A is set to an area surrounded by the lower limit of the engine load, the line of 100% of the engine load, the lower limit of the burner load control range, and the line of 100% of the cooling / heating load.

The fourth operation region is for heating the dilute solution of lithium bromide using only the burner heating that changes within the burner load control range, and corresponds to regions E and F in FIG. This region E / F is set to a region surrounded by the lower limit of the operation of the engine load, the lower limit of the operation of the absorption refrigerator ARM, the line of the engine load of 0%, and the line of the cooling and heating load of 100%.

The lower limit of the operation of the absorption refrigerator ARM is the minimum value of the cooling / heating load (%) at which the operation of the absorption refrigerator can be performed, and is a constant value determined by various conditions. The operation lower limit of the engine load is the lowest value of the gas engine load (%) at which the gas engine 1 can be operated, and is a constant value determined by the specification of the gas engine to be used. The cooling / heating capacity line due to the exhaust heat is a value that increases as the load on the gas engine 1 increases. The cooling / heating capacity line may be a curve according to the characteristics of the gas engine 1 as well as a straight line as illustrated. The lower limit of the burner load control range, that is, the lower limit of the turndown of the burner 41 is determined by the fuel control valve 4.
3 to reduce the gas fuel supply amount, and the cooling / heating load (%) obtained by the minimum heating possible by the burner 41
That is. In other words, the lower limit of the burner load control range is the minimum cooling / heating load obtained by burning the minimum gas fuel supply amount that does not cause the burner 41 to misfire,
It is a constant value determined by this heating amount and various conditions of the absorption refrigerator ARM.

Subsequently, the cooling / heating load on the vertical axis of the operation control map is obtained by calculating the ratio of the actual inlet / outlet temperature difference to the rated chilled water inlet / outlet temperature difference. The case of the cooling operation will be specifically described. The cold water inlet temperature Ti of the cold water W1 supplied to the evaporator tube 11 of the evaporator 10 from the cold water inlet line L1 and the cold water outlet line L2
Is calculated by the control unit 70 according to (1) of the following [Equation 1] based on the chilled water outlet temperature To discharged from the controller and the chilled water inlet / outlet temperature difference Ts at the rated time. The chilled water inlet temperature Ti used here is the value detected by the temperature sensor 14, and the chilled water outlet temperature To is the value detected by the temperature sensor 15, which is input to the control unit 70, and the chilled water inlet / outlet temperature difference Ts
Is a set value determined by the user. During the heating operation, it is calculated by (2) of the following [Equation 1].

(Equation 1)

The engine load on the horizontal axis of the operation control map is obtained by calculating the ratio of the power demand amount Pd to the rated power generation capacity P. More specifically, the control unit 70 calculates the following [Equation 2] based on the power demand amount Pd indicating the value of the power generation amount required for the generator and the power generation capacity P during the rated operation of the gas engine 1.
Is calculated by The power demand amount Pd is determined by the gas engine control unit 7 that is actually controlling the gas engine 1.
Is a value input to the control unit 70 from the
This is a constant value that is determined in advance by the specifications of the gas engine 1 and the generator.

(Equation 2)

Therefore, the control unit 70 calculates one engine load (the value on the horizontal axis) from the power demand amount Pd input from the gas engine control unit 7 and the power generation capacity P stored in advance as a constant value. And the temperature sensor 14
(Hot water) inlet temperature Ti input from the controller, the cold water (hot water) outlet temperature To input from the temperature sensor 15, and a preset cold water inlet / outlet temperature difference Ts, the other cooling / heating load (the value on the vertical axis). Is calculated, and the one corresponding to the point where both calculated values intersect is selected from the first to fourth operation areas provided in the above-described operation control map. As described above, when the operation area is selected from the operation control map and controlled, for example, various types of input data are sequentially determined based on a flowchart, and compared with a control method for determining an optimal operation method, the current operation is performed. The operating area (operating method) that is being controlled can be displayed on a panel, that is, displayed so that it can be visually recognized at a glance, and can be shown to an administrator or a user.
The region D / below the lower limit of operation of the absorption refrigerator ARM.
G is not selected because it is an inoperable region.

FIG. 3 is a block diagram showing main data input to the control unit 70 and main devices operated by control signals output from the control unit 70.
The control unit 70 receives the power demand amount Pd and the operation / control signal of the gas engine 1 from the gas engine control unit 7. Further, the absorption chiller ARM provides the control unit 70 with:
The chilled water outlet temperature To, the chilled water inlet temperature Ti, the opening degree of the fuel control valve 43 for supplying gaseous fuel to the burner 41 (fuel control valve opening degree), the high-pressure regenerator temperature detected by the temperature sensor 46, and the detection by the pressure sensor 47 High-pressure regenerator pressure, engine exhaust gas temperature detected by a temperature sensor (not shown) provided at an appropriate position in exhaust gas line 5, jacket water temperature detected by a temperature sensor (not shown) provided at an appropriate position in jacket water flow path 2, etc. Is entered.

The intersection of the gas engine load calculated based on the power demand amount Pd input from the gas engine control unit 7 to the control unit 70 and the cooling / heating load calculated based on the chilled water outlet temperature To and the chilled water inlet temperature Ti is determined by the operation control. If it is in the area C of the map, the fuel control valve 43 is closed to shut off the fuel supply, and the heating by the burner 41 is stopped. At the same time, the exhaust gas three-way valve 44 and the jacket water three-way valve 34
Is adjusted, and exhaust gas and jacket water are introduced into the absorption refrigerator ARM. As a result, the dilute solution of lithium bromide recovers exhaust heat from jacket water in the jacket water heat exchanger 31 and recovers exhaust heat from exhaust gas in the exhaust gas heat recovery heat exchanger 33 and the high temperature regenerator 40. So you can
An operation of heating the diluted solution using only the exhaust heat of the gas engine 1 is performed. Therefore, an operation with no fuel consumption in the burner 41 can be performed.

In the operating region C where the exhaust heat of the engine is used alone, the supply capacity may be larger than the cooling / heating load. That is, when engine exhaust heat having a heating capacity higher than the required heating capacity is supplied, the amount of refrigerant evaporated increases more than necessary, the concentration of the lithium bromide solution is increased, and the cooling / heating capacity becomes excessive. Therefore, the evaporator 10 and the absorber 2
A stabilizer valve 13 is provided in a pipeline 16 connecting between the valve and a valve opening and closing operation of the stabilizer valve 13.
The refrigerant water is supplied from the evaporator 10 to the absorber 20 as needed. When the chilled water outlet temperature To detected by the temperature sensor 15 and input to the control unit 70 is lower than a set temperature (for example, 7 ° C.), the stabilizer valve 13 is opened and closed by a control signal output from the control unit 70 to be opened. Become. As a result,
The high-concentration lithium bromide solution supplied to the absorber 20 is
Since the concentration is reduced by being diluted by the refrigerant supplied from the evaporator 10, the operation according to the cooling and heating load can be performed without controlling the introduction of the engine exhaust heat by performing such concentration adjustment. .

Next, from the gas engine control unit 7 to the control unit 7
The gas engine load calculated from the power demand amount Pd input to 0, the chilled water outlet temperature To and the chilled water inlet temperature T
If the intersection with the cooling / heating load calculated by i is in the area B of the operation control map, the opening degree of the fuel control valve 43 is set to the lower limit of the turndown to supply the minimum burner fuel and the burner 4
Heating by 1 is performed. At the same time, the exhaust gas three-way valve 4
4 and the opening degree of the jacket water three-way valve 34 are adjusted, and exhaust gas and jacket water are introduced into the absorption refrigerator ARM side.
As a result, the dilute solution of lithium bromide recovers exhaust heat from jacket water in the jacket water heat exchanger 31 and recovers exhaust heat from exhaust gas in the exhaust gas heat recovery heat exchanger 33 and the high temperature regenerator 40. As a result, the operation using the exhaust heat of the gas engine 1 to heat the dilute solution and the heating at the minimum capacity by the burner 41 in the high-pressure regenerator 40 is performed. Therefore, the operation with the minimum fuel consumption in the burner 41 can be performed.

Further, in this operation region B, since the burner 41 is operated with the turn-down lower limit set, the amount of heating by the burner 41 cannot be adjusted. Accordingly, as in the case of the above-described operation region C, the supply capacity may be larger than the cooling / heating load, and the cooling / heating capacity may be excessive. Also in such a case, the refrigerant water is supplied from the evaporator 10 to the absorber 20 by opening and closing the stabilizer valve 13 provided in the pipe 16 connecting the evaporator 10 and the absorber 20. The opening / closing operation of the stabilizer valve 13 is the same as that in the above-described operation region C. By performing such concentration adjustment, the cooling / heating load can be controlled without controlling the introduction of engine exhaust heat and the heating by the burner 41. The operation can be performed according to.

Further, in the above-described operation region B, when the supply capacity is larger than the cooling / heating load, an appropriate hysteresis is provided for the chilled water outlet temperature To, and the operation of the burner 41 is turned on.
・ Even if it is turned off, the cooling / heating capacity can be adjusted.
More specifically, for the preset value of the chilled water outlet temperature To, for example, as shown in FIG. 4, the temperatures T1 and T2 at which the burner 41 is actually turned on and off are set to α.
The width of ° C is provided. In the illustrated example, heating by the burner 41 is performed until the cold water outlet temperature falls to T1 lower than To, thereby increasing the concentration of the lithium bromide concentrated solution. And
When the cooling water outlet temperature decreases to T1 due to an increase in the cooling / heating capacity, the heating by the burner 41 is stopped at this time.

When the heating of the burner 41 is stopped, the concentration of the lithium bromide concentrated solution also decreases with a decrease in the amount of heating, so that the cooling water outlet temperature rises as the cooling / heating capacity decreases.
When the cold water outlet temperature rises to T2 in this way, the burner 41 is turned on, and the burner heating is restarted. Therefore,
Temperature difference α between T1 and T2 when the burner 41 is turned ON / OFF
Is provided, it is possible to prevent the burner 41 from repeatedly starting and stopping due to a slight temperature change. The chilled water outlet temperature To and the temperature T1 at which the burner 41 is turned ON / OFF.
T2 is not limited to the example shown in FIG. 4 and can be changed as appropriate, for example, by setting To = T1 and providing a temperature difference of α ° C. to T2.

Next, from the gas engine control unit 7 to the control unit 7
The gas engine load calculated from the power demand amount Pd input to 0, the chilled water outlet temperature To and the chilled water inlet temperature T
If the intersection with the cooling / heating load calculated by i is in the region A of the operation control map, the fuel control valve 43 is changed according to the cooling / heating load.
The heating is performed by the burner 41 whose burner fuel supply amount is adjusted by controlling the opening degree of the burner. At the same time, the openings of the exhaust gas three-way valve 44 and the jacket water three-way valve 34 are adjusted, and the exhaust gas and jacket water are introduced into the absorption refrigerator ARM. As a result, the dilute solution of lithium bromide recovers exhaust heat from jacket water in the jacket water heat exchanger 31 and recovers exhaust heat from exhaust gas in the exhaust gas heat recovery heat exchanger 33 and the high temperature regenerator 40. Therefore, the dilute solution is heated by utilizing the exhaust heat of the gas engine 1 and the high-pressure regenerator 40 is heated.
The operation using heating in accordance with the gas fuel combustion amount by the burner 41 in the inside is also performed.

In this operation region A, the burner 41 is operated within the range of the lower limit of the turndown to the burner load control range. Therefore, the heating amount by the burner 41 can be adjusted according to the gas fuel supply amount. Therefore, if the chilled water outlet temperature To detected by the temperature sensor 15 is lower than the set temperature, the fuel control valve 43
, The amount of heating by the burner 41 is reduced to lower the concentration of the lithium bromide concentrated solution. Conversely, if the chilled water outlet temperature To is higher than the set temperature, the fuel control valve 43 is operated so as to increase the opening degree to increase the concentration of the lithium bromide concentrated solution by the burner 41. Even in such an operation region A, the exhaust heat of the gas engine 1 uses the maximum value corresponding to the engine load and is operated so as to compensate for the insufficient heating amount by the burner 41, so that the gas fuel consumption is minimized. Can be suppressed.

Finally, the intersection of the gas engine load calculated based on the power demand Pd input from the gas engine control unit 7 to the control unit 70 and the cooling / heating load calculated based on the chilled water outlet temperature To and the chilled water inlet temperature Ti is determined. If it is in the region E / F of the control map, the opening degree of the fuel control valve 43 is adjusted, and the operation is performed only by heating by the burner 41. At this time, the gas engine 1 is in the region of the engine load lower than the lower operation limit position, and the exhaust gas three-way valve 44 and the jacket water three-way valve 34 are respectively operated to positions where exhaust gas and jacket water are not introduced to the absorption refrigerator ARM side. Is done. As a result,
The dilute solution of lithium bromide is heated only by the amount of heat obtained by burning gaseous fuel with the burner 41 in the high-temperature regenerator 40, and the operation for heating the dilute solution without using the exhaust heat of the gas engine 1 is performed. Will be

In this case, in the region E where the cooling / heating load is higher than the lower limit of the turndown of the burner 41, the fuel control valve 43
By controlling the opening degree, the supply amount of the gas fuel can be controlled, and the operation can be performed according to the cooling / heating load. Burner 41
In the region F where the cooling / heating load is lower than the lower limit value of the turndown, since the opening degree of the fuel control valve 43 is minimized, it is not possible to control the supply amount of the gaseous fuel and perform the operation according to the cooling / heating load. . Therefore, by opening the stabilizer valve 13 and charging the refrigerant into the absorber 20, the concentration of the lithium bromide solution can be adjusted to perform an operation according to the cooling / heating capacity.

By the way, in the cogeneration type absorption refrigerator described above, since the exhaust heat of the gas engine 1 is actively used, the load fluctuation of the gas engine 1 may affect the cooling / heating capacity. Therefore, the load change rate of the gas engine 1 is detected, and the burner 41 is determined based on the load change rate.
Is controlled by the control unit 70 so as to minimize the fluctuation of the cooling / heating capacity.

In the embodiment of the control shown in FIG. 5, the output setting value (MWD) of the generator that determines the load of the gas engine 1 is set at an output set value passing through the route and output at [Lag] through the route. The difference from the result of calculating the primary delay of the set value is calculated. By referring to this calculated value in the table [Fx], the burner control signal output value corresponding to the load change rate of the gas engine 1 is calculated (detected).
(See FIG. 5B). On the other hand, the cold water outlet temperature To
Is calculated as a difference between a detection value input from the temperature sensor 15 and a preset value. This calculated value is
After performing the proportional / integral processing in [PI], it is added to the output value of the burner control signal corresponding to the load change rate of the gas engine 1 calculated from the output setting of the generator, and the fuel valve opening command signal of the burner 41 and Become.

The control signal of the burner 41 obtained in this way reflects the load change rate of the gas engine 1. Therefore, if the combustion control of the burner 41 is performed by using this control signal, the fuel control valve 43 that supplies gas fuel to the burner 41 on the side of the absorption chiller ARM that has a slow response compared to the load fluctuation of the gas engine 1. Can be changed in advance. Therefore, it is possible to minimize the fluctuation of the temperature of the cold / hot water with respect to the fluctuation of the load of the gas engine 1, that is, the fluctuation of the cooling / heating capacity. In particular, even when there is a change in the gas engine load such that the operation region of the operation control map changes, the heating amount control of the burner 41 can be prioritized. For example, when the operation region A changes to the operation region B, , The gas fuel supplied to the burner 41 can be controlled prior to the lower limit value of the turndown.

As means and a method for taking in the operation status of the gas engine 1 into the operation control of the cogeneration type absorption refrigerator, various kinds of information are directly inputted from the gas engine control section 7 to the control section 70 as described above. In addition to
For example, a sensor may be provided on the absorption refrigerator ARM side to detect and use the temperature of the exhaust gas supplied from the gas engine 1, the temperature of the jacket water, and the like. However, when the information on the power demand amount Pd is obtained from the gas engine control unit 7 and the operation control on the absorption refrigerator ARM side is performed, there is an advantage that both can be efficiently controlled integrally. It is also possible to control the burner 41 in advance by detecting the load change rate.

As described above, according to the cogeneration absorption chiller and the operation control method using the operation control map described above, the heating source to be used can be uniquely determined according to the engine load and the cooling / heating load, and lithium bromide is used. As a heat source for heating the dilute solution, the exhaust heat of the gas engine 1 can be effectively used to the maximum, thereby saving fuel consumption. In addition, by adopting the map control, the actual driving status can be easily displayed on the panel for the user or the administrator.

The configuration of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention. For example, an internal combustion engine other than a gas engine is used as a drive source of a generator. The burner fuel is not limited to gas.

[0064]

According to the above-described cogeneration absorption refrigerator and its operation control method of the present invention, the first operation region in which heating is performed using only the exhaust heat of the engine and the lower limit of the burner load control range are set. A second operating region in which heating is performed using both burner heating and engine exhaust heat, and a third operating region in which burner heating and engine exhaust heat that change within the burner load control range are used in combination.
Since the control unit is provided with an operation control map provided with the operation region of (1) and the fourth operation region using only the burner heating, the operation region corresponding to the detected value of the cooling / heating load and the engine load is selected. , The heating source of the optimal operating region to be used can be uniquely determined.

Further, since the change rate of the load of the engine is detected and the combustion control of the burner is performed based on the change rate of the load, the fluctuation of the temperature of the hot and cold water (the fluctuation of the cooling and heating capacity) with respect to the change of the engine load is obtained. Can be minimized. Then, in an operation region (regions B, C, and F) in which the heating amount cannot be changed by controlling the supply amount of the burner fuel, cold water is supplied from the evaporator to the absorber side to adjust the concentration of the lithium bromide solution. Then, the operation according to the cooling / heating load can be performed. Further, when the cooling / heating supply capacity is larger than the cooling / heating load in the second operation region, the chilled water outlet temperature is provided with a hysteresis to turn on / off the burner. Reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a system diagram of an overall configuration showing an embodiment of a cogeneration absorption refrigerator according to the present invention.

FIG. 2 is a diagram illustrating an operation control map formed in a control unit of FIG. 1;

FIG. 3 is a block diagram relating to a control unit shown in FIG. 1;

FIG. 4 is an explanatory diagram in a case where a burner is turned ON / OFF by providing hysteresis in a chilled water outlet temperature.

FIGS. 5A and 5B are diagrams showing an embodiment in which burner combustion control is performed by detecting a load change rate of a gas engine, wherein FIG. 5A is a block diagram and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas engine 7 Gas engine control part 10 Evaporator 13 Stabilizer valve 20 Absorber 30 Low temperature heat exchanger 31 Jacket water heat exchanger 32 High temperature heat exchanger 33 Exhaust gas heat recovery heat exchanger 34 Jacket water three-way valve 40 High pressure regenerator 41 Burner 42 Exhaust gas line 43 Fuel control valve 44 Exhaust gas three-way valve 50 Low pressure regenerator 60 Condenser 70 Control unit

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat 参考 (Reference) F25B 15/00 306 F25B 15/00 306E (72) Inventor Makoto Fujiwara 2-1-1, Araimachi Shinama, Takasago-shi, Hyogo Prefecture No. 1 F term in Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (Reference) 3L060 AA03 EE35 3L093 AA01 BB11 BB22 BB26 HH02 HH08

Claims (9)

[Claims] 1. A power generator driven by an engine,
The refrigerant gas evaporated by the evaporator is absorbed and dissolved in a high-concentration solution in the absorber, and the dilute solution exiting the absorber is heated to be regenerated as a high-temperature high-concentration solution. A cogeneration absorption chiller that uses an exhaust heat of the engine as a heating source of the dilute solution, wherein the first operation of heating the dilute solution using only the exhaust heat of the engine is provided. An area, a second operation area for heating the dilute solution using the burner heating by the burner set to the lower limit of the burner load control range, and the engine exhaust heat, and a burner heating varying within the burner load control range. A third operation region in which the diluted solution is heated by using the exhaust gas and the engine exhaust heat in combination, and a fourth operation in which the diluted solution is heated using only the burner heating that changes within the burner load control range. And a control unit for selecting an operation region corresponding to the detected value of the cooling / heating load and the engine load from the operation control map. . 2. The first operation region is set to a region surrounded by an operation lower limit value of the absorption refrigerator, a cooling / heating capacity line of engine exhaust heat which increases with an engine load, and a line of 100% engine load. Wherein the second region is an operation lower limit value of the engine load,
An operation lower limit value of the absorption refrigerator, a cooling / heating capacity line of the engine exhaust heat that increases with the engine load, and an engine load 1
A third region is set in a region surrounded by a 00% line and a lower limit value of the burner load control range, and the third region is an operation lower limit value of the engine load;
An area surrounded by a line for an engine load of 100%, a lower limit of the burner load control range, and a line for a cooling and heating load of 100% is set, and the fourth area is an operation lower limit of the engine load,
2. The cogeneration type absorption refrigerator according to claim 1, wherein the absorption refrigerator is set in a region surrounded by a lower limit of operation of the absorption refrigerator, a line with an engine load of 0%, and a line with a cooling and heating load of 100%. 3. The cooling / heating load is obtained by calculating a ratio of an actual inlet / outlet temperature difference to a chilled water inlet / outlet temperature difference at a rated time, and the engine load is a ratio of a power demand amount to a rated time power generation capacity. The cogeneration absorption refrigerator according to claim 1, wherein the absorption refrigerator is obtained by: Detecting a load change rate of the engine;
The cogeneration type absorption refrigerator according to any one of claims 1 to 3, wherein combustion control of the burner is performed based on the load change rate. 5. The method according to claim 1, wherein in the first area, when the supply capacity is larger than the cooling / heating load, a refrigerant is supplied to the solution line to control the solution concentration. Cogeneration type absorption refrigerator. 6. The method according to claim 1, wherein in the second area, when the supply capacity is larger than the cooling / heating load, a refrigerant is introduced into the solution line to control the solution concentration. Cogeneration type absorption refrigerator. 7. The cogeneration system according to claim 5, wherein the solution concentration is adjusted by operating a stabilizer valve provided in a pipe connecting the evaporator and the absorber. Type absorption refrigerator. 8. The method according to claim 1, wherein when the supply capacity is larger than the cooling / heating load in the second area, a predetermined hysteresis is provided for the chilled water outlet temperature to turn on / off the burner. The cogeneration absorption refrigerator according to any one of the above. 9. A power generator driven by an engine,
The refrigerant gas evaporated by the evaporator is absorbed and dissolved in the solution in the absorber, and the diluted solution exiting the absorber is heated to be regenerated as a high-temperature high-concentration solution, and the high-concentration solution is returned to the absorber. An operation control method for a cogeneration type absorption refrigerator including an absorption refrigerator, wherein exhaust heat of the engine is used as a heating source of the dilute solution, wherein a first solution for heating the dilute solution using only exhaust heat of the engine is provided. And a second operating region in which the dilute solution is heated by using the burner heating by the burner set to the lower limit of the burner load control range and the engine exhaust heat in combination with the burner load control range. A third operating region in which the dilute solution is heated using both the burner heating and the engine exhaust heat, and a third operation region in which the dilute solution is heated using only the burner heating that changes within the burner load control range. A cogeneration system comprising: forming an operation control map including four operation regions, and selecting an operation region corresponding to the detected values of the cooling / heating load and the engine load from the operation control map to perform operation control. Operation control method of absorption refrigerator.