JP2016176603A - Absorption chiller heater, heat exchanger, control method for absorption chiller heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat recovery efficiency in an exhaust gas heat exchanger recovering heat from a gas having a temperature distribution, by using a heat medium, and to provide an absorption chiller heater to which the exhaust gas heat exchanger is applied.SOLUTION: An exhaust gas heat exchanger 400 is provided that comprises inlet piping 201 for supplying a heat medium, an inlet header pipe 203, a plurality of heat transfer tubes 205, an outlet header pipe 204, and outlet piping 202, and exchanges heat between the heat medium and a gas. A partitioning plate 407 is provided to divide the inside of the inlet header pipe, the inlet piping or a bypass pipe 404 branched from the inlet piping, is connected to a region of the divided inlet header pipe, the bypass pipe has a flow rate adjustment valve 405 for adjusting a flow rate of the heat medium, and has gas temperature sensors 401, 402 for measuring a distribution of an inlet temperature of the gas, and the outlet piping is provided with a heat medium temperature sensor 403 for measuring a temperature of the heat medium, so that an opening of the flow rate adjustment valve is adjusted on the basis of results of the measurements by the gas temperature sensor and the heat medium temperature sensor.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an absorption chiller / heater, a heat exchanger, and an absorption chiller / heater control method.

  Conventionally, an absorption chiller / heater using, for example, an aqueous lithium bromide solution as an absorbing solution and water as a refrigerant is generally known. In the cycle of the absorption chiller / heater, in order to regenerate the solution that has absorbed the refrigerant, concentration is performed by applying heat to the solution from a heating source and evaporating the refrigerant. A combustion gas generated by a burner is used as the heating source, and further heating operation can be performed, which is called a direct-fired absorption chiller / heater, and is widely used as a heat source for air conditioning. In addition, since the absorption chiller / heater can use various heat sources, it can also be driven by using high-temperature combustion exhaust gas discharged from the gas turbine as a heat source.

  Such an absorption chiller / heater is provided with a heat exchanger for recovering heat from the exhaust gas after heat is applied by a high-temperature regenerator in order to increase energy efficiency.

  Patent Document 1 describes an example of a heat exchanger that heats or cools a refrigerant.

  The heat exchanger described in Patent Literature 1 includes a plurality of tubes, a first header connected to one end of these tubes, and a second header connected to the other ends of the plurality of tubes, and the first header. Each of the second header includes a partition plate having a communication path that can be opened and closed by an electromagnetic valve so that the flow rate of the refrigerant flowing through the heat exchanger can be changed.

JP-A-4-309765

  In the absorption chiller / heater, the burner is directly connected to the high-temperature regenerator. Fuel is burned with a burner, and the combustion heat is put into a high-temperature regenerator to serve as a driving source for an absorption chiller / heater. After the heat recovery is completed, it becomes exhaust gas and is discharged from the high temperature regenerator. At that time, the thermal energy (exhaust gas temperature) of the exhaust gas is sufficiently high. Therefore, the exhaust gas is put into an exhaust gas heat exchanger, and the heat of the exhaust gas is recovered in a solution and used as a drive source for an absorption chiller / heater.

  Finally, the exhaust gas is released to the atmosphere after removing air pollutants.

  In recent years, absorption-type chiller / heaters have been moving toward larger capacities, and in order to respond to these demands, it has been required to increase the capacities of the heat exchangers constituting the entire absorption-type chiller / heater system.

  In particular, the exhaust gas heat exchanger employs a fin-and-tube heat exchanger (hereinafter referred to as “fin-tube heat exchanger”), and the height of the heat exchanger increases as the capacity increases. The direction dimension increases. That is, the inside of the exhaust gas heat exchanger has a structure in which one heat exchanger unit is multistaged in the height direction. And as the capacity of the absorption chiller / heater increases, the number of stages (height) tends to increase. Further, the high temperature regenerator and the exhaust gas heat exchanger connect the exhaust gas heat exchanger to the downstream side of the exhaust gas flow path of the high temperature regenerator via a flue duct. The exhaust gas discharged from the high-temperature regenerator passes through the flue duct, is sent to the exhaust gas heat exchanger, and recovers the heat of the exhaust gas into a solution. The heated solution is then sent to a high temperature regenerator.

  According to the means described in Patent Document 1, heat exchange in the heat exchanger is performed by changing the flow path cross-sectional area of the tube to an appropriate value by switching the solution path according to the flow rate of the solution in the tube. The characteristic that efficiency can be maintained is shown.

  It is thought that highly efficient exhaust heat recovery corresponding to the change in the flow rate of the solution can be performed by the structure. However, if there is a temperature distribution of the exhaust gas discharged from the high-temperature regenerator, there is a possibility of insufficient exhaust heat recovery. In other words, since the exhaust gas discharged from the high-temperature regenerator is in a state after passing through the high-temperature regenerator, the temperature distribution of the exhaust gas is biased depending on the solution state during heat exchange and the operating conditions of the absorption chiller / heater. It is expected that. In particular, with an increase in capacity, an exhaust gas heat exchanger that increases in size in the height direction tends to generate a temperature distribution of exhaust gas at the inlet. And when temperature distribution arises in exhaust gas, if the flow velocity in the solution tube of the heat exchanger of each stage is the same, there is a concern that the amount of exhaust heat recovery may decrease in the part through which relatively low temperature exhaust gas passes. Is done.

  An object of the present invention is to increase heat recovery efficiency in a heat exchanger that recovers heat using a heat medium containing liquid from a gas having a temperature distribution, and to apply the heat exchanger to an absorption chiller / heater. It is to improve the capacity of the absorption chiller / heater.

  The present invention includes an inlet pipe for supplying a heat medium containing a liquid, an inlet header pipe, a plurality of heat transfer pipes, a fin attached to the heat transfer pipe and contacting a gas, an outlet header pipe, and an outlet pipe. A heat exchanger for exchanging heat between the heat medium and the gas, wherein one end of the plurality of heat transfer tubes is connected to the inlet header tube, and the other end of the plurality of heat transfer tubes is the outlet header Connected to the pipe, the outlet header pipe is connected to the outlet pipe, the inlet header pipe is provided with a partition plate that divides the interior into at least two areas, and the divided inlet header pipe area has an inlet A bypass pipe branched from the pipe or the inlet pipe is connected, the bypass pipe has a flow rate adjustment valve for adjusting the flow rate of the heat medium, and has at least two gas temperature sensors for measuring the distribution of the gas inlet temperature. And the outlet piping has heat The heat medium temperature sensor that measures the temperature of the body is provided, based on the measurement results of the gas temperature sensor and the heat medium temperature sensor, adjusts the opening degree of the flow rate adjusting valve.

  According to the present invention, by increasing the heat recovery efficiency in a heat exchanger that recovers heat using a heat medium containing a liquid from a gas having a temperature distribution, and applying this heat exchanger to an absorption chiller / heater The capacity of the absorption chiller / heater can be improved.

1 is a schematic configuration diagram illustrating an absorption chiller / heater of Example 1. FIG. It is a perspective view which shows the exhaust gas heat exchanger used for the absorption type cold / hot water machine of Example 1. FIG. It is a graph which shows the temperature distribution of the waste gas of the height direction of the waste gas heat exchanger of FIG. It is a schematic cross section which shows the structure of the exhaust gas heat exchanger of FIG. 2, and the flow of the solution in the inside. It is a graph which shows the relationship between the opening degree of a flow control valve, and solution outlet temperature. It is a schematic cross section which shows the structure of the exhaust gas heat exchanger of Example 2, and the flow of the solution in the inside. It is a schematic cross section which shows the structure of the exhaust gas heat exchanger of Example 3, and the flow of the solution in the inside. It is a schematic cross section which shows the flow of the solution at the time of switching a flow control valve from the state of FIG. It is a schematic cross section which shows the structure of the exhaust gas heat exchanger of Example 4, and the flow of the solution in the inside.

  The means in the embodiment of the present invention will be described below. In addition, although the heat exchanger which concerns on this embodiment is described as an exhaust gas heat exchanger used for an absorption-type cold / hot water machine, the said heat exchanger is not limited to what is applied to an absorption-type cold / hot water machine. Moreover, it is not limited to the exhaust gas heat exchanger.

  The first means is an exhaust gas heat exchanger mainly used for an absorption chiller / heater using the combustion heat of a burner as a drive source, a solution inlet pipe, an inlet header pipe, a heat transfer pipe, a fin, and an outlet header pipe. And a solution outlet pipe, a plurality of temperature sensors for measuring the temperature of the exhaust gas flowing into the exhaust gas heat exchanger, and a temperature sensor for measuring the outlet temperature of the solution heated by the exhaust gas. is there. And the partition plate which can divide | segment the flow path through which a solution passes vertically into the inlet header pipe | tube is provided. In addition, since the inlet header tube and the heat transfer tube group are vertically divided by the partition plate, the upper side is referred to as the upper side and the lower side is referred to as the lower side for convenience of explanation. The solution inlet pipe is connected so that the solution can be supplied to the upper stage side of the inlet header pipe. Furthermore, a bypass pipe is connected to the solution inlet pipe so that the solution can be transported toward the lower side of the inlet header pipe. A flow rate adjustment valve (hereinafter referred to as “flow control valve”) is installed in the middle of the bypass piping, and the inlet header pipe (transmission) connected to the inlet header pipe is adjusted by adjusting the opening of the flow control valve. The flow rate of the solution supplied to the upper side and the lower side of the heat tube group can be made variable, and the solution supply amount can be changed based on the measurement result of the exhaust gas temperature.

  The second means connects the secondary bypass pipe so that the solution can be transported from between the solution inlet pipe of the bypass pipe and the flow control valve toward the lower side of the inlet header pipe. However, the cross-sectional area of the secondary bypass pipe is sufficiently smaller than that of the bypass pipe. By doing so, even if the flow control valve is fully closed, the solution can be always supplied to the lower side of the inlet header pipe (heat transfer pipe group) slightly.

  In addition to the structure of the first means, the third means connects the tertiary bypass pipe so that the solution can be transported from the inlet header pipe toward the solution outlet pipe. A primary solenoid valve is provided in the middle of the tertiary bypass. The solution outlet pipe is connected to the outlet header pipe via a secondary solenoid valve. By doing so, it is possible to switch the flow path connection on the upper and lower stages of the heat transfer tube group in parallel / series by opening and closing the primary solenoid valve and the secondary solenoid valve, and the exhaust gas temperature, solution outlet temperature and solution flow rate. Based on the measurement result, it is possible to control the solution flow rate in the heat transfer tube.

  Next, the effects obtained by the above means will be described.

  The opening control of the flow control valve is performed based on the measurement results of the exhaust gas temperature and the solution outlet temperature by the first and second means, and a larger amount of solution is added to the heat transfer tube group through which the higher temperature exhaust gas passes. Since it supplies, the heat | fever which waste gas has can be collect | recovered efficiently. That is, since the heat recovered in the solution is used as a drive source of the absorption chiller / heater, the refrigeration capacity is increased and the efficiency of the absorption chiller / heater is improved.

  Based on the measurement results of the exhaust gas temperature, the solution outlet temperature, and the solution flow rate, the third means controls the flow control valve, the primary solenoid valve, and the secondary solenoid valve that meet the conditions, and passes through the heat transfer tube. A decrease in the solution flow rate can be prevented, heat transfer between the exhaust gas and the solution can be promoted, and the heat of the exhaust gas can be efficiently recovered. Therefore, the same effect as described above can be obtained.

  Hereinafter, it demonstrates in detail using an Example.

  Embodiment 1 will be described with reference to FIGS.

  First, the whole structure of an absorption-type cold / hot water machine is demonstrated using FIG.

  The absorption chiller / heater 100 includes a main part 101 of the absorption chiller / heater, peripheral devices, and pipes connecting them. Here, the main part 101 of an absorption-type cold / hot water machine means the whole range represented with a dashed-dotted line in FIG.

  The main part 101 of the absorption chiller / heater includes a high temperature regenerator 102, a low temperature regenerator 103, a condenser 104, an evaporator 105, and an absorber 106. The peripheral equipment includes an exhaust gas heat exchanger 107, a high temperature heat exchanger 108, a low temperature heat exchanger 109, a solution pump 110, a refrigerant pump 111, a solution flow rate sensor 112, and a cooling tower (not shown) that releases heat of cooling water to the atmosphere. Etc.).

  Below, the case where water is used for a refrigerant | coolant and lithium bromide aqueous solution is used for a solution is demonstrated.

  The inside of the absorption chiller / heater 101 is normally maintained in a state where air components such as nitrogen and oxygen are removed, the pressure is reduced, and the refrigerant is filled with water vapor. The water vapor pressure of each part during the operation of the absorption chiller / heater 101 is highest in the high temperature regenerator, followed by “low temperature regenerator and condenser” and “evaporator and absorber” in this order. The same effect can be obtained with other refrigerants and solutions.

  Refrigerant vapor generated in the high temperature regenerator 102 and the low temperature regenerator 103 is sent to the condenser 104 through the refrigerant pipe 113 and the passage 114. The refrigerant vapor is condensed by the condenser 104 to become a liquid. Thereafter, the refrigerant passes through the refrigerant pipe 115 and is sent to the evaporator 105.

  The refrigerant sent to the evaporator 105 is dispersed from the upper part of the evaporator 105 through the refrigerant pipe 116 using the refrigerant pump 111 as power. The sprayed refrigerant evaporates, and at that time, the latent heat of vaporization is taken away to a low temperature, and the temperature of the cold water passing through the cold water pipe 117 is lowered. And the cold water 118 which temperature fell is supplied to load side, such as an air conditioning machine.

  On the other hand, the refrigerant vapor evaporated in the evaporator 105 is sent to the absorber 106, and then the refrigerant vapor is absorbed by a relatively high concentration solution (concentrated solution). The concentrated solution is sent from the high temperature regenerator 102 and the low temperature regenerator 103. The concentrated solution absorbs the refrigerant vapor and becomes a relatively low concentration solution (rare solution). This diluted solution is sent to the high temperature regenerator 102 by the solution pump 110. Here, it may be controlled so that a part of the rare solution is sent to the low temperature regenerator 103.

  The dilute solution sent to the high temperature regenerator 102 is heated and concentrated by the heat obtained by the combustion of the burner 119. At that time, the generated refrigerant vapor passes through the pipe 113 and is sent to the condenser 104 again.

  It is desirable that the dilute solution sent to the high-temperature regenerator 102 has a solution temperature as high as possible, and the concentrated solution sent to the absorber 106 has a solution temperature as low as possible. For this reason, heat exchange is performed between the concentrated solution and the diluted solution using the low temperature heat exchanger 109 and the high temperature heat exchanger 108. Further, a part or all of the dilute solution going to the high temperature regenerator 102 is sent to the exhaust gas heat exchanger 107 via the pipe 120 and further heated by the exhaust gas sent from the high temperature regenerator 102. By doing so, more heat of the exhaust gas can be recovered and the refrigeration capacity can be improved.

  As described above, the refrigerant is transported by the solution, and it is possible to continue generating cold while repeating evaporation and condensation.

  Next, the structure of the exhaust gas heat exchanger will be described with reference to FIG.

  FIG. 2 is a perspective view showing an external appearance of an exhaust gas heat exchanger used in the absorption chiller / heater of this embodiment.

  An exhaust gas heat exchanger 200 shown in this figure includes a solution inlet pipe 201 (also simply referred to as “inlet pipe”), a solution outlet pipe 202 (also simply referred to as “outlet pipe”), an inlet header pipe 203, and an outlet header pipe 204. The heat transfer tube 205, the fin 206, and a housing (not shown) are generally configured. The casing includes a heat transfer tube group that is an aggregate of the heat transfer tubes 205 and a fin group that is an aggregate of the fins 206, and is formed with an exhaust gas inlet and an outlet opened to allow the exhaust gas to pass therethrough. ing. In the heat transfer tube group and the fin group, a heat exchanger unit 207 composed of a single heat transfer tube 205 having a meandering structure and a plurality of fins 206 stacked in a direction substantially orthogonal thereto is arranged in the height direction. Laminated and multi-staged.

  In the present embodiment, for example, a case where 10 layers are stacked will be described.

  One inlet header pipe 203 is attached to each heat transfer pipe inlet of the multistage heat exchanger group. Similarly, one outlet header tube 204 is attached to the outlet of each heat transfer tube. A solution inlet pipe 201 and a solution outlet pipe 202 are attached to each header pipe.

  The flow of the solution and the exhaust gas in the exhaust gas heat exchanger will be described.

  The solution is heated by the low-temperature heat exchanger 109 by the solution pump 110, and then part or all of the solution is sent to the solution inlet pipe 201 of the exhaust gas heat exchanger 200 (indicated by reference numeral 107 in FIG. 1). And supplied to the inlet header pipe 203. The solution supplied to the inlet header tube 203 is equally distributed to each heat transfer tube 205 connected to the inlet header tube 203. The distributed solution flows inside the heat transfer tube.

  On the other hand, the exhaust gas coming from the high temperature regenerator 102 flows in the direction of the arrow 208 from the gas inlet (not shown) of the exhaust gas heat exchanger 200. The inflowing exhaust gas passes through the gaps of the fins 206 attached to the heat transfer tube group. At that time, the heat of the exhaust gas is recovered by the fin 206, and the heat is recovered from the fin 206 to the heat transfer tube 205 and from the heat transfer tube 205 to the solution. The exhaust gas is sent to the gas outlet (not shown) of the exhaust gas heat exchanger 200 while heat is recovered in the solution, and is sent in the direction of the arrow 209.

  The solution flows in the heat transfer tube toward the outlet header tube 204 while recovering the heat of the exhaust gas. The heated solution flowing in each heat transfer tube is collected by the outlet header tube 204 and sent to the solution outlet pipe 202. The solution exiting the exhaust gas heat exchanger 200 passes through the pipe 121, joins the pipe 122 exiting the high temperature heat exchanger 108, and is supplied to the high temperature regenerator 102.

  Next, in the exhaust gas heat exchanger, the temperature distribution of the supplied exhaust gas, the structure of the exhaust gas heat exchanger 200 corresponding to the temperature distribution, and the flow rate control of the solution will be described with reference to FIGS.

  FIG. 3 shows an example of the exhaust gas temperature distribution at the exhaust gas inlet of the exhaust gas heat exchanger 200. The vertical axis indicates the position in the height direction at the exhaust gas heat exchanger inlet, and the horizontal axis indicates the exhaust gas temperature.

  As described above, in the high temperature regenerator 102, the rare solution is heated by the combustion heat of the burner 119. The aspect of heat transfer from the exhaust gas to the solution changes depending on the flow state of the dilute solution inside the high-temperature regenerator 102. Therefore, there are a part where the amount of heat recovered from the exhaust gas is large and a part where the heat recovery amount is small, and as a result, a temperature distribution of the exhaust gas occurs at the outlet of the high temperature regenerator 102 (inlet of the exhaust gas heat exchanger). In the present embodiment, an example will be described in which an exhaust gas temperature distribution is formed such that the upper side is high and the lower side is low at the inlet of the exhaust gas heat exchanger 200. However, the formed temperature distribution is not limited to this.

  FIG. 4 shows a configuration of an exhaust gas heat exchanger and a solution flow rate control method capable of recovering as much heat of exhaust gas as possible even when exhaust gas temperature distribution occurs.

  The exhaust gas heat exchanger 400 of the present invention includes temperature sensors 401 and 402 for measuring the temperature of exhaust gas, a temperature sensor 403 for measuring the outlet temperature of the solution, a solution inlet pipe 201, a solution outlet pipe 202, an inlet header pipe 203, and an outlet header. A pipe 204, a heat transfer pipe 205, fins (not shown), a bypass pipe 404 and a flow rate adjustment valve 405 (hereinafter referred to as a “flow control valve”), and a flow control valve based on the exhaust gas temperature and the solution outlet temperature. The flow rate control unit 406 controls the opening degree. The basic configuration of the exhaust gas heat exchanger 400 is as described in FIG. In addition, the present invention is characterized by having the following structure.

  That is, the inlet header pipe 203 is divided into an upper stage side and a lower stage side by the partition plate 407. The solution inlet pipe 201 is branched upstream of the connection portion with the inlet header pipe 203, and is connected to the lower inlet header pipe 203 through the bypass pipe 404 therefrom. A flow control valve 405 is provided in the middle of the bypass pipe 404. In FIG. 4, M indicates the flow rate of the solution supplied to the upper side of the inlet header pipe 203, and m indicates the flow rate of the solution supplied to the lower side.

T _g1 is the exhaust gas temperature measured by the temperature sensor 401 near the upper stage side, and T _g2 is the exhaust gas temperature measured by the temperature sensor 402 near the lower stage side. These are sent as electrical signals to the control unit 406.

  Table 1 shows the control of the opening degree of the flow regulating valve.

With the configuration as described above, based on the temperature measurement results T _g1 and T _g2 of the exhaust gas, the temperature distribution of the exhaust gas flowing into the exhaust gas heat exchanger 400 is high on the upper side 408 and low on the lower side 409. When it determines ( _Tg1 > _Tg2 ), the opening degree of the flow control valve 405 is made small. That is, as much solution as possible is supplied to the heat transfer tube group through which the exhaust gas having a high temperature passes, and the heat of the exhaust gas is efficiently recovered. On the other hand, when the exhaust gas temperature is the same on the upper side 408 and the lower side 409 or the high temperature is on the lower side 409 (T _g1 ≦ T _g2 ), the flow control valve 405 is fully opened.

  FIG. 5 shows the relationship between the opening degree of the flow control valve 405 and the solution temperature in the solution outlet pipe 202 after heat exchange between the solution and the exhaust gas.

  As shown in this figure, there is an opening at which the solution temperature in the solution outlet pipe becomes maximum between the case where the opening degree of the flow control valve is fully closed and the case where it is the previous time. By adjusting to such an opening degree, the outlet temperature of the solution rises, and heat recovery from the exhaust gas to the solution can be performed efficiently.

  The adjustment (control) of the opening degree of the flow control valve described above is performed by measuring the temperature of the solution by the temperature sensor 403 provided in the solution outlet pipe 202 shown in FIG. 4 and finely adjusting the opening degree of the flow control valve 405. Do. In this case, feedback control, feedforward control, or the like can be applied.

  Example 2 will be described with reference to FIG.

  In this figure, in addition to the structure and means of the first embodiment, a secondary bypass pipe 701 is further provided. The cross-sectional area of the secondary bypass pipe 701 is much smaller than that of the bypass pipe 702 (reference numeral 404 in FIG. 4). The secondary bypass pipe 701 is connected to the flow control valve 703 of the bypass pipe 702 and the solution inlet pipe 201 and the other end is connected to the lower side of the inlet header pipe 203.

  By adopting such a structure, even when the flow control valve 703 (reference numeral 405 in FIG. 4) is fully closed, the heat transfer tube group on the lower side 409 is always in accordance with the ratio of the flow path cross-sectional areas of both bypass pipes. It is also possible to flow the solution. That is, when the flow control valve 703 is completely closed with the structure of the first embodiment, the solution is not supplied to the heat transfer tube group on the lower side 409, and the filled solution is stopped. The retained solution may be heated and boiled by the heat of the exhaust gas. Then, when bubbles generated by boiling flow to the outlet header tube 204 by buoyancy, there is a concern that the pressure loss of the solution flow may increase due to the compressibility of the bubbles. Therefore, as described above, even if the secondary bypass pipe 701 is provided and the flow control valve 703 is completely closed, the solution is always supplied to the heat transfer tube group on the lower side 409, and the solution stays in the heat transfer tube group. Therefore, it is possible to avoid boiling of the solution and prevent an increase in pressure loss of the solution flow.

  A third embodiment of the present invention will be described with reference to FIGS.

  The present embodiment is effective mainly when the absorption chiller / heater is started, for example, when idling. When the absorption chiller / heater starts up, the flow rate of the solution does not reach the rated value, and the flow rate is low. That is, when the solution flow rate is reduced in Examples 1 and 2, the flow rate of the solution flowing in each heat transfer tube is reduced. As a result, there is a concern that the heat transfer between the exhaust gas and the solution is reduced, and the heat that can be recovered from the exhaust gas is reduced.

  In this embodiment, even when the flow rate of the solution is relatively small, such as when an absorption chiller / heater is started, the heat of a large amount of exhaust gas is recovered in the solution.

  The structure of the exhaust gas heat exchanger 800 of this embodiment and the flow state of the solution will be described below.

  In the present embodiment, in addition to the structure of the first or second embodiment, a tertiary bypass pipe 801, a primary electromagnetic valve 802, and a secondary electromagnetic valve 803 are provided. The tertiary bypass pipe 801 is connected to the lower side of the inlet header pipe 203 and the other end is connected to the solution outlet pipe 202. A primary electromagnetic valve 802 is provided in the middle of the tertiary bypass pipe 801, and a secondary electromagnetic valve 803 is provided between the outlet header pipe 204 and a portion where the tertiary bypass pipe 801 is connected to the solution outlet pipe 202. .

  In the present embodiment having such a structure, for example, the following control is performed.

  First, the solution flow rate value Q measured by the solution flow rate sensor 112 shown in FIG. 1 is transmitted to the flow rate control unit 406. If the solution flow rate value Q does not reach the rating, it is determined that the operation is low flow rate, and the flow control valve 804 ( Corresponds to the reference numeral 405 in FIG. 4), the primary solenoid valve 802 is fully opened, and the secondary solenoid valve 803 is fully closed. Then, the solution is supplied to the upper side inlet header pipe 203, passes through the heat transfer pipe group on the upper stage side 408, and flows to the upper part of the outlet header pipe 204. Then, it flows to the lower part of the outlet header pipe 204, passes through the heat transfer pipe group on the lower stage side 409, and is sent to the lower stage side of the inlet header pipe 203. Thereafter, it flows through the tertiary bypass pipe 801 to the solution outlet pipe 202.

  When the starting state is finished and the solution flow rate reaches the rated state, as shown in FIG. 8, the flow control valve 804 is gradually opened, the primary solenoid valve 802 is fully closed, and the secondary solenoid valve 803 is fully opened. . Thereafter, the flow shifts to the solution flow rate control based on the exhaust gas temperature and the solution outlet temperature described in the first embodiment.

  That is, when the heat transfer tube group of the exhaust gas heat exchanger 800 is divided into upper and lower parts and the solution flow rate is small, the solution is caused to flow in series with both. Then, the cross-sectional area of the heat transfer tube through which the solution passes is halved, and the solution flow rate is doubled. Therefore, the heat transfer rate between the heat of the exhaust gas and the solution can be kept high by maintaining the solution flow rate in the heat transfer tube high. When the solution flow rate reaches the rated state, the solution is allowed to flow in parallel through both heat transfer tube groups.

  Table 2 summarizes the control of the opening degree of the flow rate adjusting valve described above.

The control corresponding to the exhaust gas temperatures T _g1 and T _g2 during rated operation is the same as that shown in Table 1.

  Embodiment 4 of the present invention will be described with reference to FIG.

  The present embodiment is an example in which the division number of the inlet header pipe 1100 (corresponding to reference numeral 203 in FIG. 4) is changed in the first or second embodiment.

  As shown in FIG. 9, the inlet header pipe 1100 is divided into three parts of an upper stage side 1103, a middle stage side 1104, and a lower stage side 1105 by a partition plate 1101 and a secondary partition plate 1102. In the three regions, exhaust gas temperature sensors 1106, 1107, and 1108 corresponding to the respective regions are provided. Further, a branch is provided on the downstream side of the flow control valve 1110 of the bypass pipe 1109, one is connected to the middle side 1104 of the inlet header pipe 1100 via the secondary flow control valve 1111 and the other is connected to the branch part. Further, it is connected to the lower side 1105 of the inlet header pipe 1100 via the bypass pipe 1112. The bypass pipe 1112 is provided with a tertiary flow regulating valve 1113.

By adopting such a structure, it is possible to cope with a more complicated exhaust gas temperature distribution. For example, when the temperature of the exhaust gas passing through the upper stage 1103, the middle stage 1104, and the lower stage 1105 of the heat transfer tube group is high in the order of the upper stage T _g1 > lower stage T _g3 > middle stage T _g2 , the tertiary flow regulating valve 1113 is fully opened. Then, the opening degree of the flow control valve 1110 and the secondary flow control valve 1111 is finely adjusted based on the measurement result of the solution outlet temperature. If a bypass pipe and a flow control valve corresponding to each of the three or more parts are provided, a more complicated exhaust gas temperature distribution can be dealt with, and more exhaust gas heat can be recovered. Thereby, the refrigerating capacity can be improved.

  DESCRIPTION OF SYMBOLS 100: Absorption-type hot / cold water machine, 101: Main part of absorption-type cold / hot water machine, 102: High temperature regenerator, 103: Low temperature regenerator, 104: Condenser, 105: Evaporator, 106: Absorber, 107: Exhaust gas heat Exchanger, 108: High temperature heat exchanger, 109: Low temperature heat exchanger, 110: Solution pump, 111: Refrigerant pump, 112: Solution flow sensor, 113: Refrigerant piping, 114: Passage, 115: Refrigerant piping, 116: Refrigerant Piping, 117: Cold water piping, 118: Outlet cold water, 119: Burner, 120: Solution piping, 121: Solution piping, 122: Solution piping, 200: Exhaust gas heat exchanger, 201: Solution inlet piping, 202: Solution outlet piping, 203: Inlet header pipe, 204: Outlet header pipe, 205: Heat transfer pipe, 206: Fin, 207: Heat exchanger unit, 208: Exhaust gas inflow direction, 209: Exhaust gas outflow , 401: exhaust gas temperature sensor, 402: exhaust gas temperature sensor, 403: solution temperature sensor, 404: bypass piping, 405: flow rate adjustment valve, 406: flow rate control unit, 407: partition plate, 408: upper stage side, 409: lower stage Side, 701: secondary bypass pipe, 702: bypass pipe, 703: flow rate adjustment valve, 800: exhaust gas heat exchanger, 801: tertiary bypass pipe, 802: primary solenoid valve, 803: secondary solenoid valve, 804: Flow rate adjusting valve, 1100: inlet header pipe, 1101: primary partition plate, 1102: secondary partition plate, 1103: upper stage side, 1104: middle stage side, 1105: lower stage side, 1106: exhaust gas temperature sensor, 1107: exhaust gas temperature sensor, 1108: Exhaust gas temperature sensor, 1109: Bypass pipe, 1110: Flow rate adjusting valve, 1111: Flow rate adjusting valve, 1112: Bypass , 1113: the flow control valve.

Claims (7)

An absorption chiller / heater using an absorption liquid as a heat medium and a combustion source of fuel supplied to a burner as a drive source,
A regenerator for concentrating the absorption liquid, and an exhaust gas heat exchanger for recovering heat from the exhaust gas generated by the burner,
The exhaust gas heat exchanger includes an inlet pipe for supplying the heat medium, an inlet header pipe, a plurality of heat transfer pipes, a fin attached to the heat transfer pipe and in contact with the exhaust gas, an outlet header pipe, and an outlet pipe. , And performs heat exchange between the heat medium and the exhaust gas,
One end of the plurality of heat transfer tubes is connected to the inlet header tube,
The other end of the plurality of heat transfer tubes is connected to the outlet header tube,
The outlet header pipe is connected to the outlet pipe;
The inlet header pipe is provided with a partition plate that divides the inside into at least two regions,
A bypass pipe branched from the inlet pipe or the inlet pipe is connected to the divided area of the inlet header pipe,
The bypass pipe has a flow rate adjusting valve for adjusting the flow rate of the heat medium,
Having at least two gas temperature sensors for measuring the distribution of the inlet temperature of the exhaust gas,
The outlet pipe is provided with a heat medium temperature sensor for measuring the temperature of the heat medium,
An absorption chiller / heater that adjusts an opening degree of the flow rate adjustment valve based on measurement results of the gas temperature sensor and the heat medium temperature sensor. The bypass pipe is provided with a secondary bypass pipe that connects the upstream side and the downstream side of the flow regulating valve,
The absorption chiller / heater according to claim 1, wherein a flow passage cross-sectional area of the secondary bypass pipe is smaller than a flow passage cross-sectional area of the bypass pipe. A tertiary bypass pipe connecting one of the plurality of regions of the inlet header pipe and the outlet pipe;
The tertiary bypass pipe is provided with a primary solenoid valve,
The outlet pipe is provided with a secondary solenoid valve on the upstream side of the connection portion of the tertiary bypass pipe in the outlet pipe,
By adjusting the opening of the flow rate adjusting valve, the primary solenoid valve and the secondary solenoid valve,
The absorption chiller / heater according to claim 1 or 2, wherein the flow direction of the heat medium in a plurality of regions of the inlet header pipe can be changed. An inlet pipe for supplying a heat medium containing liquid, an inlet header pipe, a plurality of heat transfer pipes, a fin attached to the heat transfer pipe and in contact with gas, an outlet header pipe, and an outlet pipe;
A heat exchanger for exchanging heat between the heat medium and the gas,
One end of the plurality of heat transfer tubes is connected to the inlet header tube,
The other end of the plurality of heat transfer tubes is connected to the outlet header tube,
The outlet header pipe is connected to the outlet pipe;
The inlet header pipe is provided with a partition plate that divides the inside into at least two regions,
A bypass pipe branched from the inlet pipe or the inlet pipe is connected to the divided area of the inlet header pipe,
The bypass pipe has a flow rate adjusting valve for adjusting the flow rate of the heat medium,
Having at least two gas temperature sensors for measuring the distribution of the inlet temperature of the gas,
The outlet pipe is provided with a heat medium temperature sensor for measuring the temperature of the heat medium,
A heat exchanger that adjusts an opening degree of the flow rate adjustment valve based on measurement results of the gas temperature sensor and the heat medium temperature sensor. The bypass pipe is provided with a secondary bypass pipe that connects the upstream side and the downstream side of the flow regulating valve,
The heat exchanger according to claim 4, wherein a flow passage cross-sectional area of the secondary bypass pipe is smaller than a flow passage cross-sectional area of the bypass pipe. A tertiary bypass pipe connecting one of the plurality of regions of the inlet header pipe and the outlet pipe;
The tertiary bypass pipe is provided with a primary solenoid valve,
The outlet pipe is provided with a secondary solenoid valve on the upstream side of the connection portion of the tertiary bypass pipe in the outlet pipe,
By adjusting the opening of the flow rate adjusting valve, the primary solenoid valve and the secondary solenoid valve,
The heat exchanger according to claim 4 or 5, wherein the flow direction of the heat medium in a plurality of regions of the inlet header pipe can be changed. Using the absorption liquid as a heat medium, using the combustion heat of the fuel supplied to the burner as the drive source,
A control method for an absorption chiller-heater having an absorber, an evaporator, a regenerator for concentrating the absorption liquid, a condenser, and an exhaust gas heat exchanger for recovering heat from the exhaust gas generated by the burner. There,
The exhaust gas heat exchanger includes an inlet pipe for supplying the heat medium, an inlet header pipe, a plurality of heat transfer pipes, a fin attached to the heat transfer pipe and in contact with the exhaust gas, an outlet header pipe, and an outlet pipe. , And performs heat exchange between the heat medium and the exhaust gas,
One end of the plurality of heat transfer tubes is connected to the inlet header tube,
The other end of the plurality of heat transfer tubes is connected to the outlet header tube,
The outlet header pipe is connected to the outlet pipe;
The inlet header pipe is provided with a partition plate that divides the inside into at least two regions,
A bypass pipe branched from the inlet pipe or the inlet pipe is connected to the divided area of the inlet header pipe,
The bypass pipe has a flow rate adjusting valve for adjusting the flow rate of the heat medium,
Having at least two gas temperature sensors for measuring the distribution of the inlet temperature of the exhaust gas,
The outlet pipe is provided with a heat medium temperature sensor for measuring the temperature of the heat medium,
Based on the measurement results of the gas temperature sensor and the heat medium temperature sensor, the opening of the flow rate adjustment valve is adjusted,
A tertiary bypass pipe connecting one of the plurality of regions of the inlet header pipe and the outlet pipe;
The tertiary bypass pipe is provided with a primary solenoid valve,
The outlet pipe is provided with a secondary solenoid valve on the upstream side of the connection portion of the tertiary bypass pipe in the outlet pipe,
By adjusting the opening of the flow rate adjusting valve, the primary solenoid valve and the secondary solenoid valve,
The direction of the flow of the heat medium in a plurality of regions of the inlet header pipe can be changed,
A flow sensor for measuring the flow rate of the absorbing liquid flowing out of the absorber;
When the flow rate measured by the flow sensor is small, the control method for the absorption chiller-heater is configured such that the primary solenoid valve is fully opened and the secondary solenoid valve is fully closed.

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