KR200362500Y1 - Cogeneration system - Google Patents

Abstract

A cogeneration system has been disclosed that increases heat recovery by efficient heat exchange and minimizes losses during heat exchange. The disclosed system includes an engine coolant heat exchanger 20 interposed between a first exhaust gas heat exchanger 10 at an end of an exhaust pipe 7, an engine coolant circulation pipe 6, and a second exhaust gas heat exchange interposed between an exhaust pipe 7. Physical characteristics and temperature changes of the exhaust gas and the engine coolant, including the gas 30, the third exhaust gas heat exchanger 40 for the exhaust manifold, the heat exchange water pipe 8 through each heat exchanger, and the hot water tank 50, respectively. In order to perform the heat exchange step by step, and to ensure the maximum heat transfer capacity in each heat exchange process and to implement the optimal heat exchange conditions with minimal loss, the heat loss is extremely low and the heat recovery rate maximizes the overall energy utilization efficiency.

Description

Cogeneration System {Cogeneration system}

The present invention relates to a cogeneration system, and more particularly, to a cogeneration system having a high heat recovery rate by minimizing losses during an efficient heat exchange and heat exchange process.

Fossil fuel, the primary energy, is gradually being depleted, but demand is increasing, and the supply and demand imbalance is intensifying. As a way to solve this problem, a cogeneration system with high energy use efficiency is proposed as an alternative. The cogeneration system produces power and heat simultaneously from a single energy source, and its energy use efficiency is much higher than that of a conventional thermal power generation system. Specifically, in the case of thermal power generation system, the power generation efficiency is about 40%, and considering the transmission loss, the overall efficiency is only about 35%. The heat generation (engine exhaust gas heat and cooling water heat) is generated 1.5 ~ 2 times as much as the heat required for power generation. According to the cogeneration system, the energy efficiency is improved by recovering the heat and using it for cooling and heating. It can be increased to more than 70%.

In Patent No. 10-0149466, a system that uses a gas engine, including a heat recovery pipe and a heat pipe circulating naturally by using it as a heat source in a cooling jacket of a gas engine, has been proposed a system that functions as a heat pump type of heating and cooling air conditioning. .

Patent No. 10-0411764 discloses a primary heating tank (primary exhaust gas heat exchanger) for heating water first by using the end portion of an engine exhaust pipe as a heat source, and primary heated water using a starting portion of an exhaust pipe between the primary heating tank and the engine as a heat source. A system for supplying hot water has been proposed, including a secondary heating tank (secondary exhaust gas heat exchanger) for secondary heating.

In Patent Application Publication No. 2000-0058568, a generator directly connected to an internal combustion engine, a gas turbine generator driven by an exhaust gas of an internal combustion engine, and a cooling water of an internal combustion engine are heated to a saturation temperature by heat exchange with the exhaust gas, and then raised to a supercritical pressure with an evaporator and a superheater. A system including a steam turbine generator driven by superheated steam has been proposed.

Korean Patent Laid-Open Publication No. 2001-0000614 proposes a system including a hydraulic transmission control device installed between a multi-turbine shaft and a generator in order to improve power generation by reducing power generation load and increasing torque.

Patent Publication 2002-0005826 includes a gas turbine generator, a waste heat recovery boiler for generating high-temperature, high-pressure steam as exhaust gas discharged from the gas turbine generator, and a cooling / heating working fluid heat exchanger and an absorption chiller using steam generated from the waste heat recovery boiler. A system is proposed.

Conventionally, various methods of recovering the engine arrangement as described above have been proposed, but the flow of the engine exhaust gas, the engine coolant, and the heat exchange water is not optimized, and the loss in each heat exchange well is not taken into consideration. There was a limit to increase, and the maximum loss of calories that can not be recovered by self loss is still high, about 30%.

The purpose of the present invention is to optimize the engine heat recovery line, to ensure the maximum heat transfer capacity during the heat exchange process on the recovery line, and to minimize the loss in order to achieve more economical energy use, the cogeneration system with higher heat recovery rate. To provide.

1 is a whole heat exchange system diagram of the cogeneration system according to the present invention.

Figure 2 is a schematic diagram of the heat exchanger for the exhaust gas used in the cogeneration system according to the present invention.

Figure 3 is a schematic diagram of the heat exchanger for the engine coolant used in the cogeneration system according to the present invention.

Figure 4a to 4c is a cross-sectional view in each direction of the exhaust manifold combined exhaust gas heat exchanger used in the cogeneration system according to the present invention.

Explanation of symbols on the main parts of the drawings

1: engine 2: generator

6: engine coolant circulation pipe 7: exhaust pipe

8: heat exchanger pipe 10,20,30,40: heat exchanger

50: hot water tank

Cogeneration system according to the present invention for achieving the above object is an engine that generates axial force by burning diesel or liquefied natural gas or liquefied petroleum gas as fuel, a generator directly connected to the engine, water jacket and cooling water circulation for engine cooling In the pipe, an exhaust manifold of the engine and an exhaust pipe, a first exhaust gas heat exchanger for heating water using the exhaust pipe end of the engine as a heat source, and the first exhaust gas using the engine coolant circulation pipe of the water jacket as a heat source. An engine coolant heat exchanger for heating the first heated water in a heat exchanger, a second exhaust gas heat exchanger for heating the second heated water in the engine coolant heat exchanger using the middle portion of the exhaust pipe of the engine as a heat source, and the exhaust of the engine. A third exhaust gas heat exchange for an exhaust manifold for heating the water heated in the second exhaust gas heat exchanger in the third exhaust gas heat exchanger And that the hot water tank and to discharge a predetermined amount after the storage for the water heated by the engine baegida combine the exhaust gas heat exchanger equipped with its features.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the cogeneration system according to the present invention.

Heat exchange schematic diagram of the cogeneration system according to the present invention is shown in FIG. As shown, the cogeneration system according to the present invention produces electric power with an engine 1, which is a reciprocating internal combustion engine, and a generator 2 directly connected thereto. Here, the engine 1 is a multi-cylinder engine, and abbreviates the general diesel engine which uses diesel as a fuel, and the general gas engine which uses natural liquefied gas or natural petroleum gas. The engine 1 includes a conventional fuel supply device, a cooling device, and an intake / exhaust device. For convenience, the engine 1 includes a water jacket (3) of the cooling device, an engine coolant tank (4), a circulation pump (5), and an engine coolant circulation pipe ( 6) The exhaust manifold (see FIGS. 3A to 3C, reference numeral 41) of the exhaust device and the exhaust pipe 7 are shown.

According to the present invention, the first exhaust gas heat exchanger (10) installed at the end of the exhaust pipe (7), the engine coolant heat exchanger (20) interposed in the middle of the engine coolant circulation pipe (6), interposed between the exhaust pipe (7) The second exhaust gas heat exchanger 30, the third exhaust gas heat exchanger 40 for the exhaust manifold, the heat exchange water pipe 8 which passes through each heat exchanger in turn, and the hot water tank 50 are provided.

Preferably, the first exhaust gas heat exchanger 10 having the lowest exhaust gas temperature is positioned at a lower position than the exhaust gas manifold third exhaust gas exchanger 40 having the highest exhaust gas temperature, and the second exhaust gas having the intermediate temperature exhaust gas is retained. The exhaust gas heat exchanger 30 is positioned higher than the first exhaust gas heat exchanger 10 and lower than the third exhaust gas heat exchanger 40, and the engine coolant heat exchanger 20 on the engine coolant circulation pipe 6 is removed. Placed higher than the first exhaust gas heat exchanger 10 and lower than the second exhaust gas heat exchanger 30. Further, with respect to the water jacket 1, the inflow side of the engine coolant circulation pipe 6 was connected to the lowest position of the water jacket 3, and the outflow side thereof was connected to the highest position in the diagonal direction. This arrangement generally takes into account the characteristics that heat naturally moves from high temperature to low temperature, so that smooth movement of each fluid and efficient heat exchange can be achieved in response to temperature changes of exhaust gas, engine coolant and heat exchange water.

As shown in FIG. 2, the first and second exhaust gas heat exchangers 10 and 30 described above have a cylindrical portion 11 having a diameter larger than that of the exhaust pipe 7 of the exhaust gas described above, and in the cylindrical portion 11, respectively. Two axial spaces forming a heat exchange water discharge space (12, 12 ') between the inner surface at both ends in the axial direction and forming a heat exchange water (water) residence space therebetween at a distance from each other. Intermediate plates 14 and 15, a plurality of small diameter pipes 16 for distributing and discharging flue gas through two intermediate plates 14 and 15, and exhaust gas holding spaces 12 and 12 'of the cylinder portion 11 Inlet (18) for connecting the above-mentioned heat exchange water pipe (8) to the heat exchange water retention space (13) of the inlet (17) and the outlet (17 '), the cylindrical portion 11 for connecting the above-described exhaust pipe (7) And the outlet 18 '. Preferably, the cylindrical portion 11 is placed horizontally in the axial direction, and in such a posture, the inlet 17 of the exhaust gas is placed at a position higher than the outlet 17 'but the exhaust gas stays in the cylindrical portion 11. It penetrates the highest point of the space 12, and the outlet 17 ′ is positioned at a lower position than the inlet 17 but penetrates the lowest point of the exhaust gas holding space 12 in the cylinder portion 11. The inlet 18 of the heat exchange water is the lowest at the end of the exhaust gas outlet side in the heat exchange water residence space 13 of the cylindrical portion 11, and the outlet 18 ′ is the exhaust gas inlet side of the residence space 13. Go through each of the highest points at the end. By this posture and positional relationship, heat loss can be minimized and optimal heat exchange conditions can be achieved. That is, since the exhaust gas is mostly gaseous and its specific gravity is smaller than that of water, when the inflow side is made higher than the outlet side, the exhaust gas holding spaces 13 and 13 'in the cylinder portion 11 are discharged in the state filled with the exhaust gas, and the maximum It has heat transfer ability of. In addition, since the inlet side has a higher inlet side than the outlet side in the exhaust gas holding spaces 13 and 13 ', the heat exchange water temperature in the heat exchange water holding space 13 is lower than the outlet side, According to the above conditions, heat exchange is performed first from the place where the heat exchange water temperature is the highest, so that the heat exchange efficiency is high and the loss due to freezing can be minimized.

For reference, the inlet 18 of the first exhaust gas heat exchanger 10 may be directly connected to a water pipe (not shown) and directly supplied with tap water, and preferably, bubbles may be discharged from the water supply by being connected through a water separator (not shown). Inflow can be prevented.

As shown in FIG. 3, the engine coolant heat exchanger 20 includes a cylindrical portion 21 having a diameter larger than that of the engine coolant circulation pipe 6 described above, and an engine coolant residence space 22 and 22 ′. To distribute the engine coolant through the two intermediate plates 24 and 25 and the two intermediate plates 24 and 25 to form a heat exchange water (water) retention space 23 therebetween. Inlet 27 and outlet 27 'for connecting the above-described engine coolant circulation pipe 6 to the plurality of small water pipes 26 and the engine coolant residence spaces 22 and 22' of the cylindrical portion 21 to be circulated. ), And an inlet port 28 and an outlet port 28 'for connecting the heat exchange water pipe 8 described above to the heat exchange water residence space 23 of the cylindrical portion 21. The engine coolant heat exchange 20 has a structure substantially the same as that of the exhaust gas heat exchanger 10 of FIG. 2, except that the heat medium is substantially liquid, unlike the exhaust gas described above. With respect to the inlet 27, the inlet 27 is positioned at a lower position than the outlet 27 'but passes through the lowest portion of the engine coolant residence space 22 in the cylinder portion 21, and the outlet 27' is the inlet. It is placed at a position higher than (27), but penetrates the highest point of the engine cooling water staying space 22 'in the cylindrical portion 21. That is, the liquid engine coolant flows in from the lowest place and flows out from the highest place to fill the engine coolant residence space 23 with the engine coolant without bubbles. Therefore, the maximum heat transfer capacity is achieved with the maximum heat transfer capacity. It can be created.

The third exhaust gas heat exchanger 40 for use as the exhaust manifold has a space around the exhaust manifold portion 41 and the exhaust manifold portion 41 as shown in the cross-sectional views in each direction shown in FIGS. 4A to 4C. It is composed of a heat exchange jacket portion 42 wrapped in an airtight state and connected to both ends of the heat exchange water pipe 8 described above. The exhaust manifold portion 41 has a structure substantially the same as a conventional exhaust manifold attached to a multi-cylinder engine, and further includes a passage 43 for circulating heat exchange water from one end to the other end according to the present invention. Have. That is, the heat exchange water introduced into the heat exchange jacket portion 42 is distributed and distributed around the exhaust manifold portion 41 and through the heat exchange water passage 43 so that the heat exchange efficiency can be increased with a sufficient heat exchange area.

The hot water tank 50 is for storing hot water that is finally heat exchanged in the third exhaust gas heat exchanger 40 for an exhaust manifold, and has a hot water output pipe 51 for outputting the stored hot water to the outside. Preferably, the hot water output pipe 51 carries hot water at the highest point in the tank and at a higher position than the aforementioned heat exchange water pipe 8 associated with the tank or the aforementioned heat exchangers on the heat exchange water pipe 8. If the tank position in the system is lower than other equipment, a part of the hot water output pipe 51 has a bent part 51a through the highest point. Thus, by preventing the bubbles in the hot water tank 50 and filled with hot water it is possible to prevent heat loss such as cooling by the bubbles.

The hot water tank 50 may also be provided with an electric heater 52 driven by commercial power as an auxiliary heating means of the stored hot water. Of course, other heating means such as a gas boiler is also possible instead of the electric heater.

On the other hand, the branch output pipe 53 is branched from the heat exchange water pipe 8 between the third exhaust gas heat exchanger 40 for the exhaust manifold and the hot water tank 50, and the opening and closing valves 54 and 55 on the branch side are formed. A flow regulating valve 56 at the inlet side of the triple gas heat exchanger 40 is provided. The flow regulating valve 56 allows to adjust the flow rate of the heat exchange water flowing into the third exhaust gas heat exchanger 40 for the exhaust manifold, and according to the flow rate of the final heat exchange water through the third exhaust gas heat exchanger 40. Allows you to control the temperature or produce steam. Therefore, by opening and closing the valves 54 and 55 alternately with the flow rate control, it is possible to output hot water for hot water supply or steam for steam heating through the branch output pipe 53. The flow regulating valve 56 and the opening / closing valves 54 and 55 are automatically controllable using a conventional sensor and control circuit (not shown).

As described above, in the cogeneration system according to the present invention, in recovering the arrangement by the engine exhaust gas and the engine cooling, stepwise heat exchange and each heat exchange process in response to the physical state and temperature change of the exhaust gas and the engine coolant It is realized as the best heat exchange condition that guarantees maximum heat transfer capacity and minimizes the loss. The heat loss is extremely low and the heat recovery rate can be increased to more than 90% of the total energy use efficiency.

Claims (11)

In the engine including the engine that generates axial force by burning fuel, the generator directly connected to the engine, the water jacket and engine coolant circulation pipe for cooling the engine, the exhaust manifold and exhaust pipe of the engine, A first exhaust gas heat exchanger for heating water using an end portion of the exhaust pipe of the engine as a heat source, an engine coolant heat exchanger for heating water first heated in the first exhaust gas heat exchanger using the engine coolant circulation pipe as a heat source, and A second exhaust gas heat exchanger for heating the secondary heated water in the engine cooling water heat exchanger using the middle portion of the engine exhaust pipe as a heat source, and water heated in the second exhaust gas heat exchanger using the exhaust manifold of the engine as a heat source A cogeneration system comprising: a third exhaust gas heat exchanger for both heating and a hot water tank for storing and discharging a predetermined amount of water heated in the exhaust manifold exhaust gas heat exchanger. 2. The position of claim 1, wherein the first exhaust gas heat exchanger is positioned at a lower position than the exhaust gas manifold third exhaust gas heat exchanger, and the second exhaust gas heat exchanger is higher than the first exhaust gas heat exchanger and lower than the third exhaust gas heat exchanger. And the engine coolant heat exchanger is positioned above the first exhaust gas heat exchanger and below the second exhaust gas heat exchanger. The said 1st and 2nd exhaust gas heat exchanger of Claim 1 or 2 has the cylindrical part 11 which is larger in diameter than the exhaust pipe of an engine, and this cylindrical part 11 is spaced apart from the inner surface at both ends in the axial direction, respectively. Two intermediate plates (14, 15) and two intermediate plates (14, 15) forming a flue gas retention space (12, 12 ') and forming a heat exchange water retention space (13) therebetween with a mutual distance therebetween. Inlet 17 and outlet for connecting the above-described exhaust pipe 7 to a plurality of small diameters 16 for distributing and distributing the flue gas through therebetween, and to the flue gas retention spaces 12 and 12 'of the cylindrical portion 11. (17 '), a cogeneration system comprising an inlet (18) and an outlet (18') for connecting the heat exchange water pipe (8) described above to the heat exchange water residence space (13) of the cylindrical portion (11). 4. The exhaust gas according to claim 3, wherein the cylinder part 11 is placed horizontally in the axial direction, and the inlet port 17 of the exhaust gas is positioned at a position higher than the outlet port 17 ′, and the exhaust gas stays in the cylinder part 11. It penetrates the highest point of the space 12, and the outlet 17 'is positioned at a lower position than the inlet 17, but the lowest point of the exhaust gas holding space 12' in the cylindrical portion 11 is The inlet 18 of the heat exchange water is the lowest at the end of the exhaust gas outlet side in the heat exchange water residence space 13 of the cylindrical portion 11, the outlet 18 'is the residence space 13 Cogeneration system, characterized in that configured to penetrate the highest point at each end of the inlet gas inlet. The engine coolant heat exchanger according to claim 1 or 2, wherein the engine coolant heat exchanger has a cylinder portion 21 having a diameter larger than that of the engine coolant circulation pipe, and the cylinder portion 21 is spaced apart from the inner surfaces at both ends in the axial direction, respectively. Between two intermediate plates 24 and 35 and two intermediate plates 24 and 35 that form cooling water retention spaces 22 and 32 'and also form a heat exchange water retention space 23 therebetween with a mutual distance therebetween. A plurality of small diameter water pipes 26 for dispersing and distributing the engine coolant through the pipes, and inlets 27 for connecting the aforementioned engine coolant circulation pipes to the engine coolant residence spaces 22 and 32 'of the cylindrical portion 21; A cogeneration system comprising an inlet port (27 ') and an outlet port (28) for connecting the heat exchange water pipes to the heat exchange water residence space (23) of the cylindrical portion (21). The method of claim 5, wherein the cylindrical portion 21 is placed horizontally in the axial direction, the inlet 27 is positioned at a lower position than the outlet 27 ', but the engine coolant residence space in the cylindrical portion 21 ( Penetrates the lowest point of 22, and the outlet 27 'is positioned higher than the inlet 27, but penetrates the highest point of the engine coolant retention space 22' in the cylinder 21. Wherein the inlet 28 of the heat exchange water is the lowest at the end of the exhaust gas outlet side in the heat exchange water residence space 23 of the cylindrical portion 21, the outlet 28 'is the exhaust gas in the residence space 23 Cogeneration system, characterized in that configured to penetrate the highest point at each inlet end. The exhaust pipe manifold and the third exhaust gas heat exchanger according to claim 1 or 2, wherein the exhaust manifold portion 41 connected to the engine and the exhaust manifold are exhausted and surrounded in an airtight state with a space around the exhaust manifold portion 41. Cogeneration system, characterized in that consisting of a heat exchange jacket portion 42 is connected to the heat exchange water pipe. The cogeneration system according to claim 7, further comprising a passage (43) through which the third exhaust gas heat exchanger for both exhaust manifolds passes from one end of the exhaust manifold portion (41) to the other end to distribute heat exchange water. . 2. The hot water tank according to claim 1, characterized in that the hot water tank has a hot water output pipe 51 piped to discharge hot water at the highest position than the heat exchange water pipe or other devices on the heat exchange water pipe to output the stored hot water. Cogeneration system. The cogeneration system according to claim 1 or 9, further comprising auxiliary heating means capable of heating hot water stored in the hot water tank. 2. The branch output pipe 53 branched from the heat exchange water pipe between the exhaust manifold combined third exhaust gas heat exchanger and the hot water tank, the opening and closing valves 54 and 55 provided at each branch side, and the third exhaust gas. Cogeneration system characterized in that the flow control valve 56 for controlling the flow rate at the inlet side of the heat exchanger (40) is provided to output the hot water or steam through the branch output pipe in accordance with the flow rate control.