JP2010144995A - Refrigerating system utilizing exhaust heat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating system utilizing exhaust heat capable of operating refrigerating equipment with high energy efficiency by effectively using the excess steam of wide fluctuation in flow rate. <P>SOLUTION: The refrigerating system includes an economizer 2 producing steam by utilizing exhaust heat from an engine 1, a power generating device 8 generating power by rotating a steam turbine 7 by supplying the steam from the economizer 2, and a compression type refrigerating machine 15 driving a compressor by the generated power and producing cold heat, further includes the other steam utilizing device 10 to which a part of the steam supplied to the steam turbine 7 is supplied, and the other steam utilizing device 10 has fluctuation in the use of the steam. The refrigerating system further includes an absorption type refrigerating machine 11 including a regenerator to which the excess steam 23 is supplied from the other steam utilizing device 10 to be heated thereby, and a heat exchanger 12 for pre-cooling the cooling water 27 supplied to the compression type refrigerating machine 15, by the cold heat produced by the absorption type refrigerating machine 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides a system for generating steam using exhaust heat from an exhaust gas generation source, generating electric power using the exhaust heat of the steam, and supplying a part of the steam to other steam using facilities for use. The present invention also relates to a waste heat utilization refrigeration system that generates cold by driving a refrigerator using the generated electric power.

2. Description of the Related Art Conventionally, a cogeneration system that promotes efficient energy utilization by taking out power, warm heat, or cold energy using exhaust heat of exhaust gas discharged from an internal combustion engine has been widely used. For example, when a refrigeration facility is provided in addition to an internal combustion engine such as a refrigerated container ship or various factory facilities, there is a waste heat utilization refrigeration system that operates the refrigeration facility using exhaust heat of exhaust gas generated by the internal combustion engine.
For example, Patent Document 1 (Japanese Patent Laid-Open No. 2004-69276) and Patent Document 1 (Japanese Patent Laid-Open No. 2003-207224) disclose a cogeneration system including a refrigeration facility.

  FIG. 5 shows a schematic configuration diagram when the system is applied to a refrigeration container ship as an example of a conventional exhaust heat utilization refrigeration system. The exhaust gas generated by the main engine 1 mounted on the refrigerated container ship is introduced into the economizer 2, and the water supply A is heated by the economizer 2 to generate steam. This steam is mainly supplied to the steam turbine 7, and the steam turbine 7 is rotated by the steam to drive the generator 8 to generate electricity. The electric power generated here is supplied to the compression refrigerator 15 that cools the cargo compartment 16 and the like, and is used as electric power for driving the compressor of the compression refrigerator 15. The steam discharged from the steam turbine 7 is condensed by the condenser 9 and sent to the feed water A.

  The refrigerated container ship is provided with in-steam steam utilization equipment 10 other than the steam turbine 7, such as an air conditioner and a hot water generator. Therefore, a part of the steam generated by the economizer 2 is also supplied to these other onboard steam utilization facilities 10. However, as for the other on-board steam utilization equipment 10, the actual situation is that the amount of steam used varies greatly depending on the time zone and the situation. Accordingly, the surplus steam that is not used in the other in-steam steam utilization facility 10 is not a constant amount, and therefore this surplus steam is condensed by the condenser and used for the feed water A.

JP 2004-69276 A JP 2003-207224 A

However, as shown in FIG. 5, if the surplus steam from another steam utilization facility is condensed and used for water supply, the thermal energy of the steam is wasted, leading to a decrease in energy efficiency. I will. However, other steam utilization facilities, like a steam turbine, have a large variation in the amount of steam used, so that stable utilization is difficult.
In recent years, for example, container ships have been increased in size and demanded to increase the cooling capacity, but as a result, the required power has increased and the power generation system has to be increased in size. However, increasing the size of the power generation system leads to a reduction in equipment to be cooled, such as cargo compartments, and thus there is a problem that it cannot be increased unnecessarily.

  Therefore, in view of the above-described problems of the prior art, the present invention provides an exhaust heat utilization refrigeration system that can operate refrigeration equipment in an energy efficient manner by effectively using surplus steam with a large flow rate fluctuation. With the goal.

Therefore, in order to solve such a problem, the present invention provides an economizer that generates steam using exhaust heat from an exhaust heat generation source, and supplies steam generated by the economizer to rotate a steam turbine to generate power. A power generation device to perform, and a compression type refrigerator that drives a compressor with electric power generated by the power generation device to generate cold heat, and a part of the steam supplied to the steam turbine is branched and supplied In the exhaust heat utilization refrigeration system equipped with other steam utilization devices,
The other steam utilization device has a variation in the amount of steam used, and an absorption refrigerator having a regenerator supplied with surplus steam from the other steam utilization device and heated by the supplied surplus steam;
And a heat exchanger for precooling the cooling water supplied to the compression refrigerator by the cold generated by the absorption refrigerator.

According to the present invention, an absorption refrigerator is arranged in series before the compression refrigerator, and the cooling water supplied to the compression refrigerator is pre-cooled by the cold generated by the absorption refrigerator. It is possible to reduce the power consumption of the refrigerator.
Further, surplus steam having a large flow rate fluctuation can be effectively used, and the energy efficiency of the entire system can be improved.

A steam flow measuring means for measuring the flow rate of the surplus steam; and a control device for controlling the number of revolutions of the compressor of the compression type refrigerator based on the surplus steam flow measured by the steam flow measuring means; Is provided.
As described above, since the flow rate of surplus steam varies greatly, the amount of cold heat generated by the absorption chiller also varies, and the cooling water after pre-cooling supplied to the compression chiller by the flow rate of surplus steam is generated. The temperature will also change. Therefore, the cooling capacity of the compression refrigerator can be maintained constant by controlling the rotation speed of the compressor included in the compression refrigerator based on the flow rate of excess steam by the control device.

Furthermore, a heat storage heat exchanger is provided in the preceding stage of the absorption refrigerator.
As described above, by providing the heat storage type heat exchanger, it is possible to level the fluctuation of the cooling capacity due to the fluctuation of the flow rate of the surplus steam, and it is possible to simplify the operation control of the compression type refrigerator.

Furthermore, the heat exchanger is a regenerative heat exchanger.
Thus, by providing a regenerative heat exchanger as an alternative to the heat exchanger, it is possible to level the fluctuations in the cooling capacity due to fluctuations in the surplus steam flow without installing a new heat exchanger. It becomes possible to simplify the operation control of the compression refrigerator.

In addition, a plurality of the heat storage heat exchangers are provided in parallel, and a valve for controlling the amount of refrigerant supplied to each heat storage heat exchanger is provided,
Steam flow measuring means for measuring the flow rate of the surplus steam, and a control device for controlling the number of operations of the regenerative heat exchanger by controlling the opening and closing of the valve based on the surplus steam flow measured by the steam flow measuring means. And is provided.
In this way, by increasing or decreasing the number of operation of the regenerative heat exchanger according to the flow rate of surplus steam, it becomes possible to perform control according to fluctuations in surplus steam without installing a large-scale regenerative heat exchanger.
Further, the above-described exhaust heat utilization refrigeration system is a system mounted on a refrigeration container ship, and the other steam utilization device is an inboard steam utilization device including an on-board cargo warehouse, and is generated by the compression refrigerator. Preferably, the in-steam steam utilization device is cooled by the generated cold heat.

As described above, according to the present invention, the absorption chiller is arranged in series before the compression chiller, and the cooling water supplied to the compression chiller is pre-cooled by the cold generated by the absorption chiller. As a result, it is possible to reduce the power consumption of the compression refrigerator.
Further, surplus steam having a large flow rate fluctuation can be effectively used, and the energy efficiency of the entire system can be improved.
Furthermore, by providing a heat storage type heat exchanger, it is possible to level the fluctuations in the cooling capacity due to fluctuations in the flow rate of surplus steam, and it is possible to simplify the operation control of the compression type refrigerator.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
In the present embodiment, steam is generated using exhaust heat from the exhaust gas generation source, the refrigerator is driven by the electric power generated using the exhaust heat of the steam, and a part of the steam is used for other steam utilization facilities. The present invention is applied to all refrigeration systems using exhaust heat that are supplied to and used as an example. Hereinafter, a case where the present system is applied to a refrigeration container ship will be described as an example.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a waste heat utilization refrigeration system according to Embodiment 1 of the present invention.
A refrigerated container ship is equipped with a main engine 1 that drives the ship, and an economizer 2 that generates steam using exhaust gas discharged from the main engine 1 is provided. The economizer 2 includes a steam drum 6 to which feed water 22 is supplied. The feed water 22 is first introduced from the steam drum 6 into the heat exchanger 5 and heated, and a mixed fluid of water and steam is returned to the steam drum 6. After that, only steam is introduced into the heat exchanger 5 and heated to generate saturated steam (hereinafter abbreviated as steam). This steam is mainly sent to the steam turbine 7. The exhaust gas cooled by the economizer 2 is discharged from the chimney 3 through a predetermined exhaust gas treatment.
The steam turbine 7 is rotated by the steam generated by the economizer 2, and drives a generator 8 that is connected to the steam turbine 7. The electric power generated by the generator 8 is fed to a compression refrigerator 15 described later.

  The compression refrigerator 15 is a well-known device including a compressor (not shown), a condenser, a decompression device such as an expansion valve, and an evaporator. The compression refrigerator 15 has a refrigerant cycle formed by the above-described equipment, and cools the cargo chamber 30 by supplying cold heat 30 generated by the evaporator to the cargo chamber 16. It has become. The compression refrigerator 15 has a configuration in which cooling water 27 is supplied to cool the compressor or the condenser, and the drainage 29 after cooling is discharged. The cooling water 27 is preferably seawater. Further, as described above, the compressor included in the compression refrigerator 15 is driven by the electric power generated by the generator 8.

A portion 22 of the steam generated by the economizer 2 is supplied to the ship steam utilization facility 10. The in-steam steam utilization facility 10 is a steam utilization facility 10 other than the steam turbine 7, such as an in-air cooling / heating device, a hot water generation device, and the like. Further, the in-vessel steam utilization facility 10 varies in the amount of steam used depending on the time zone and the situation.
Therefore, the surplus steam 23 that has not been used in the inboard steam utilization facility 10 is supplied to the absorption refrigerator 11.

The absorption refrigerator 11 is a known device including a regenerator, a condenser, an evaporator, and an absorber. Specifically, the absorption refrigerator 11 heats an absorption liquid containing a refrigerant to vaporize and separate the refrigerant from the absorption liquid, and cools the vaporized refrigerant separated by the regenerator to condense and liquefy the refrigerant. The condenser to be condensed, the liquefied refrigerant condensed in the condenser to be dropped on the surface of the evaporation heat exchanger through which the heat transfer heat medium passes, and the evaporator to be evaporated in a low-pressure atmosphere and the cooling heat medium pass An absorption heat exchanger is disposed adjacent to the evaporation heat exchanger, and a high-concentration absorption liquid whose concentration has been increased by the regenerator is dropped on the surface of the absorption heat exchanger to remove the absorption heat. And an absorber that causes the absorbing liquid to absorb the vaporized refrigerant evaporated in the evaporator.
The surplus steam 23 is used as a heat source for heating the regenerator of the absorption refrigerator 11.

  Furthermore, the heat exchanger 12 which pre-cools the cooling water 27 of the compression refrigerator 15 with the cold heat produced | generated with the said absorption refrigerator 11 is provided. In the heat exchanger 12, the refrigerant cooled by the evaporator of the absorption chiller 11 flows on the low temperature side, and the cooling water 27 supplied to the compression chiller 15 flows on the high temperature side. Heat exchange is performed between the two and the cooling water 27 is precooled.

  As described above, according to the present embodiment, the absorption chiller 11 is arranged in series before the compression chiller 15, and the cooling water supplied to the compression chiller 15 by the cold generated by the absorption chiller 15. By pre-cooling 27, it is possible to reduce the power used by the compression refrigerator. Further, surplus steam having a large flow rate fluctuation can be effectively used, and the energy efficiency of the entire system can be improved.

Further, as a configuration to which the present embodiment is applied, the steam flow measuring means 41 for measuring the flow rate of the surplus steam 23 of the in-vessel steam utilization facility 10 and the surplus steam flow measured by the steam flow measuring means 41 are used. It is preferable to provide a control device 42 that controls the rotational speed of the compressor of the compression refrigerator 15.
As described above, since the flow rate of the surplus steam 23 varies greatly, the amount of cold heat generated by the absorption refrigerator 11 also varies, and after the precooling supplied to the compression refrigerator 15 by the flow rate of the surplus steam 23. The temperature of the cooling water 27 also changes. Therefore, the control device 42 can maintain the cooling capacity of the cargo compartment 16 at a constant level by controlling the rotational speed of the compressor included in the compression refrigerator 15 based on the flow rate of the surplus steam 23.

(Embodiment 2-1)
Embodiments 2-1 to 2-3 below have a configuration in which heat storage means is added to the configuration of the first embodiment described above. In Embodiments 2-1 to 2-3, detailed description of the same configurations as those in Embodiment 1 is omitted.

FIG. 2 is a schematic configuration diagram of the exhaust heat utilization refrigeration system according to Embodiment 2-1 of the present invention.
This system has a configuration in which a regenerative heat exchanger 45 is provided upstream of the absorption chiller 11. In the regenerative heat exchanger 45, the surplus steam 23 of the in-vessel steam utilization facility 10 flows to the high temperature side, and the heat medium for heating the regenerator of the absorption refrigeration machine 11 flows to the low temperature side. A structure for heating the medium is provided. The heat storage heat exchanger 45 includes a casing loaded with a heat storage body, and after flowing the surplus steam 23 from one end of the casing to the other end to heat the heat storage body, the heat medium is flowed from the other end to one end to store the heat storage. The heat medium is heated by the heat stored in the body. The heat storage body is appropriately selected from a latent heat storage body, a sensible heat storage body, and the like, and a ceramic body having a large heat capacity is preferably used.

  As described above, the flow rate of the surplus steam 23 changes from moment to moment due to in-vessel steam demand, so the cooling temperature of the compression refrigerator 15 may fluctuate abruptly. However, as in this embodiment, a regenerative heat exchanger By providing 45, load fluctuations can be leveled, and the operation control of the compression refrigerator 15 can be simplified.

(Embodiment 2-2)
FIG. 3 is a schematic configuration diagram of the exhaust heat utilization refrigeration system according to Embodiment 2-2 of the present invention.
In this configuration, a heat storage heat exchanger 46 is provided in the subsequent stage of the absorption refrigerator 11. That is, the heat exchanger 12 shown in Embodiment 1 is replaced with a heat storage heat exchanger 46. In the heat storage heat exchanger 46, the refrigerant cooled by the evaporator of the absorption chiller 11 flows to the low temperature side, and the cooling water 27 supplied to the compression chiller 15 flows to the high temperature side. Heat exchange is performed between these, and the cooling water 27 is pre-cooled. The heat storage heat exchanger 46 includes a casing loaded with a heat storage body, and after cooling the heat storage body by flowing the refrigerant of the absorption refrigeration machine 11 from one end to the other end of the casing, The cooling water 27 is cooled by the cold energy stored in the heat storage body. The heat storage body is appropriately selected from a latent heat storage body, a sensible heat storage body, and the like, and water or the like is preferably used.
By providing the heat storage type heat exchanger 46 as in the present embodiment, it is possible to level the fluctuation of the cooling capacity due to the fluctuation of the flow rate of the surplus steam 23 and to simplify the operation control of the compression refrigerator 15. It becomes possible.

(Embodiment 2-3)
FIG. 4 is a schematic configuration diagram of an exhaust heat utilization refrigeration system according to Embodiment 2-3 of the present invention. The present embodiment 2-3 is a configuration applicable to the above-described embodiments 2-2 and 2-3. Here, the configuration applied to the embodiment 2-2 will be described as an example.
This configuration has a configuration in which a plurality of regenerative heat exchangers 45 a, 45 b, 45 c are arranged in parallel in the front stage of the absorption refrigerator 11. Although the figure shows a configuration in which three heat storage heat exchangers are arranged in parallel, the number is not limited.

Among the heat storage type heat exchangers, the two heat storage type heat exchangers 45b and 45c have valves 47b and 47c on the flow path to which the surplus steam 23 is supplied, and the flow through which the heat medium of the absorption refrigerator 11 is supplied. Valves 48b and 48c are provided on the road so that the number of operating heat storage heat exchangers 45a to 45c can be controlled.
Further, the steam flow measuring means 41 for measuring the flow rate of the surplus steam 23, and the valves 47b, 47c, 48b, 48c are controlled to open and close based on the surplus steam flow measured by the steam flow measuring means 41, and the heat storage type heat And a control device 42 that controls the number of operating the exchangers 45a to 45c.

In this configuration, when the flow rate of the surplus steam 23 measured by the steam flow rate measuring means 41 is large, the control device 42 controls the valves 47b, 47c, 48b, 48c to be opened, and the regenerative heat exchanger 45a. All of ~ 45c are activated. On the other hand, when the flow rate of the surplus steam 23 measured by the steam flow rate measuring means 41 is small, all the valves 47b, 47c, 48b and 48c are closed by the control device 42, or the valves 47b and 48b or 47c are closed. Only one of the combination of the valve 48c and the valve 48c is controlled to be closed to reduce the number of operating the heat storage type heat exchangers 45a to 45c.
As described above, by controlling the number of operation of the heat storage heat exchangers 45a to 45c in accordance with the flow rate of the surplus steam 23, the control according to the fluctuation of the surplus steam can be performed without installing a large heat storage heat exchanger. It becomes possible.

  The present invention generates steam by using exhaust heat from an exhaust gas generation source, drives a refrigerator with electric power generated using the exhaust heat of the steam, and partially uses the steam for other steam utilization equipment. In the refrigeration system using exhaust heat that is supplied and used, the refrigeration equipment can be operated energy-efficiently by using surplus steam that has a large flow rate fluctuation discharged from other steam-use equipment. It can be widely applied to ships and various refrigeration factories.

It is a schematic block diagram of the exhaust-heat utilization refrigeration system which concerns on Embodiment 1 of this invention. It is a schematic block diagram of the exhaust-heat utilization refrigeration system which concerns on Embodiment 2-1 of this invention. It is a schematic block diagram of the exhaust-heat utilization refrigeration system which concerns on Embodiment 2-2 of this invention. It is a schematic block diagram of the exhaust-heat utilization refrigeration system which concerns on Embodiment 2-3 of this invention. It is a schematic block diagram of the waste heat utilization refrigeration system mounted in the conventional refrigeration container ship.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Economizer 7 Steam turbine 8 Generator 9 Condenser 10 Inboard steam utilization equipment 11 Absorption refrigeration machine 12 Heat exchanger 15 Compression refrigeration machine 21 Exhaust gas 22 Branched steam 23 Surplus steam 41 Steam flow measuring means 42 Control device 45 45a, 45b, 45c, 46 Regenerative heat exchanger 47b, 47c, 48b, 48c Valve

Claims (6)

An economizer that generates steam using exhaust heat from an exhaust heat generation source, a power generation apparatus that is supplied with steam generated by the economizer and rotates a steam turbine to generate power, and electric power generated by the power generation apparatus And a compression type refrigerator that drives the compressor to generate cold heat, and a waste heat utilization refrigeration system comprising another steam utilization device to which a part of the steam supplied to the steam turbine is branched and supplied In
The other steam utilization device has a variation in the amount of steam used, and an absorption refrigerator having a regenerator supplied with surplus steam from the other steam utilization device and heated by the supplied surplus steam;
A waste heat utilization refrigeration system, comprising: a heat exchanger that precools cooling water supplied to the compression chiller by cold generated by the absorption chiller.   A steam flow measuring means for measuring the flow rate of the surplus steam, and a control device for controlling the number of revolutions of the compressor of the compression type refrigerator based on the surplus steam flow measured by the steam flow measuring means. The exhaust heat utilization refrigeration system according to claim 1.   The waste heat utilization refrigeration system according to claim 1 or 2, wherein a heat storage type heat exchanger is provided in front of the absorption chiller.   The exhaust heat utilization refrigeration system according to claim 1 or 2, wherein the heat exchanger is a regenerative heat exchanger. A plurality of the heat storage heat exchangers are provided in parallel, and valves for controlling the amount of refrigerant supplied to each heat storage heat exchanger are provided,
Steam flow measuring means for measuring the flow rate of the surplus steam, and a control device for controlling the number of operations of the regenerative heat exchanger by controlling the opening and closing of the valve based on the surplus steam flow measured by the steam flow measuring means. And a waste heat utilization refrigeration system according to claim 3 or 4.   The exhaust heat utilization refrigeration system according to any one of claims 1 to 5 is a system mounted on a refrigeration container ship, wherein the other steam utilization apparatus is an inboard steam utilization apparatus including a cargo warehouse in the ship, and the compression type An exhaust heat utilization refrigeration system, wherein the in-steam steam utilization device is cooled by cold heat generated by a refrigerator.

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