JP2007024023A - Rankine cycle engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems in a cogeneration system of a conventional Rankine cycle engine wherein the size is increased, the cost is increased, and the increase of performance is hard since a high temperature heat exchange part (heater) heating a working medium for driving and a water heating part (water heater) for generating hot water by exhaust heat are formed separately, and particularly excessive heat insulation is applied therearound to prevent the loss of heat radiation from these devices to the outside from occurring. <P>SOLUTION: In this system, the heater 10 is installed in a hot water device to minimize heat loss, and an efficiency is improved, device systems are facilitated, and cost is reduced. A heat medium provided from a high temperature heat source is introduced into the heater from the outside to heat and evaporate mainly a working fluid in a liquid state. To properly control the temperature, the periphery of the heater is simply insulated or the inflow state of the heat medium is controlled. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention is intended to achieve high efficiency utilization of a high-temperature heat source for driving a Rankine cycle engine and simplification of the system, and the power obtained from the engine is used to drive a generator or a compressor and at the same time exhaust heat thereof. The present invention relates to a system used for so-called cogeneration that can be effectively used as hot water or hot water. If this is directly linked to other various heat engines, high-temperature fuel cells, etc., and the high-temperature exhaust heat is used as a heat source, the energy efficiency of the entire system including them can be dramatically improved. Efficiency, diversity of heat sources, quietness, and cleanliness of exhaust gas can be put into practical use with a simple structure, and convenience, energy saving, environmental harmony, etc. not available with existing engines such as conventional internal combustion engines are required. It can be used in general energy equipment application fields.

The Rankine cycle engine has been expected to be put to practical use because of its excellent characteristics as described above, unlike the conventional mainstream internal combustion engine. However, compared to internal combustion engines, the overall mechanism tends to be complicated due to external heat transfer, working fluid characteristics, restrictions on high temperature and high pressure, etc., and there is much room for improvement in durability and responsiveness and cost. It was also expensive and lacked competitiveness. However, in recent years, as the response to the energy environment has changed in the direction of seeking better ones, it is expected that this institution can be fully put into practical use by selecting a use from the aforementioned characteristics and making it a system compatible with this. It is becoming. After generating electricity with small gas turbines, general internal combustion engines, solid oxide fuel cells (SOFCs), and molten carbonate fuel cells (MCFCs), as well as high-temperature exhaust heat from combustion equipment systems in factories and stores This heat-driven engine is optimal so that high-temperature exhaust heat, which is still at the level of several hundred degrees, can be used to newly produce electric power and hot water to improve the overall heat utilization efficiency. As an example, when combined with an SOFC with a single power generation efficiency of about 45%, it is expected that the total power generation efficiency is about 60%, and the power generation cogeneration is about 80% or more.

In conventional Rankine cycle engines for cogeneration, the temperature of the driving heat source is relatively high (approximately 200 degrees Celsius or higher) and the heater that heats the working thermal fluid and the water heater that heats the water with its residual heat are lower than that ( Therefore, they were provided as separate bodies. For this reason, the heater on the high temperature side was wrapped with a heavy insulating material to reduce heat leakage to the outside, and it was bulky and expensive, but still heat loss could not be prevented completely. Also, the working fluid and the heat medium pipe flow path connecting them are complicated and the heat loss is large. The present invention solves this problem and at the same time attempts to simplify and improve the efficiency of the entire system by effectively utilizing the cooling exhaust heat of the thermally driven engine.

The present invention uses a high-temperature heat medium obtained from a high-temperature heat source, and first exchanges the working fluid inside the heater, which is the driving force source of the engine, through a high-temperature section radiator to a predetermined temperature of about 200 degrees Celsius or higher. In a two-stage heating system that heats the water for heating and hot water supply at a lower temperature and then heat-exchanges in the water heater using the same low-temperature radiator and heats it to about 100 degrees Celsius. The heater on the side is included in the water heater on the low temperature side to solve the problem, and at the same time, heat radiation for cooling of the engine is also appropriately performed in the water heater to further improve the thermal efficiency and solve the problem. Is.

The present invention can solve the conventional problems by using the above-described means. The surroundings of the heater that reaches a high temperature were conventionally at room temperature, but in this plan, the temperature of the hot water is higher. As a result, the heat insulation around the heater can be greatly simplified and integrated with the water heater, so that the overall size can be reduced. In addition, the connecting pipe from the heater to the water heater does not require heat insulation, and molding is simplified. As described in the previous section, the cooling exhaust heat of the heat-driven engine can be used effectively for heating hot water, and the efficiency can be improved.

As described above, a high-temperature heater is provided inside a lower-temperature water heater to simplify the heat insulation of the high-temperature portion, and the hot water in the water heater is mainly structured by heating with a low-temperature radiator and a heat-driven engine cooler.

The present invention will be described based on the basic configuration system diagram of FIG. 1 as an embodiment. The Rankine cycle engine uses water, fluorocarbons such as R113 as the working fluid (9), organic substances such as toluene and octane, etc., and is heated to a high temperature of about 200 degrees Celsius or higher by the heater (10). What is in a state is sent to the expander (11) where it generates power when it is adiabatically expanded to a low pressure. In the closed cycle system as in this example, in order to cool the gas and return it to the liquid (condensate), the cooler (12) and the pressurizer (pressurizing the liquid and feeding it again to the high-pressure heater (10) ( 14). Here, the heater (10) holds the working fluid (9) in a liquid state below the liquid level (15), and a high temperature radiator (6) is provided there, and 200 degrees Celsius passes through the inside. It is heated and vaporized by the above high-temperature heat medium. This high-temperature heat medium flows from the inlet (5) and is sent to the heated water heater main body (1). Here, the water heater main body (1) is provided so as to include the heater (10) therein. For this reason, the above-mentioned heat medium immediately heats the water under the warm water level (4) through the low temperature radiator (7) provided inside the water heater body (1) to generate hot water, and then from the heat medium outlet (8). Released to the outside. In addition, the original cold water of warm water enters from the inlet (2) provided relatively below, and is taken out as warm water of predetermined temperature from the warm water outlet (3). Here, the cooler (12) is provided below the warm water level (4) to heat the water to generate warm water, and at the same time, the working fluid is cooled and begins to recover. If this condensate is insufficient, an auxiliary cooler (13) is provided outside the water heater main body (1) at the subsequent stage as necessary, and heat is appropriately radiated to the outside air or water to complete the condensate. Moreover, the outer periphery of the heater (10) is appropriately covered with a simple heat insulating material (16) as necessary to adjust the heat radiation to the warm water in the surrounding water heater. In addition, the arrow in the figure shows the flow direction of the fluid.

As a result of the foregoing, this engine is a simple system that can be expected to have high efficiency, but generally, the higher the temperature of the working fluid, the higher the efficiency. For this reason, water is often used at several hundred degrees Celsius or higher, and organic materials are often used at lower temperature, and a configuration that matches the temperature of the heat source and the required performance characteristics is required. For this reason, for example, the high-temperature part radiator (6) is provided with a device (not shown) for controlling the flow rate and flow of the high-temperature heat medium so that the heat radiation capacity can be changed, and the performance of the heat insulating material (16) is optimized. It is also necessary to make a selection or to make a part of the working fluid (9) come into contact with the vapor in order to superheat the working fluid (9). As described above, the heat insulating material (16) is naturally simpler than the conventional one. Similarly, the water heater body (1) is provided with conventional insulation (not shown).

As described above, according to the present invention, a highly practical Rankine cycle engine having a relatively simple heat exchanger structure and high practicality can be realized, and can be utilized in many technical industrial fields as described at the beginning. Become. Recently, it has been studied to make effective use of so-called sustainable energy such as solar heat and bio-productive heat, and it is expected to spread to many fields of use that require improvement of energy environment as well as economic efficiency. It is obvious that the same principle according to the gist of the present invention can be applied to a cogeneration system using a heat driven engine such as a Stirling cycle or a Brayton cycle other than the Rankine cycle engine.

The basic composition system figure of the present invention is shown.

Explanation of symbols

(1) Hot water heater body (2) Cold water inlet (3) Hot water outlet (4) Hot water liquid level (5) High temperature heat medium inlet (6) High temperature part radiator (7) Low temperature part radiator (8) Heat medium outlet ( 10) heater (11) expander (12) cooler (13) auxiliary cooler (14) pressurizer (15) working fluid liquid level (16) heat insulating material

Claims (3)

A heat exchanger that generates hot water by exhaust heat after power is taken out by a Rankine cycle engine. A heat exchanger that drives the engine by introducing a high-temperature working medium from an external high-temperature heat source to heat the working fluid and its heat exchanger A system configured to enclose a container (heater) in a heat exchanger that generates warm water by the exhaust heat and the container (heater). A system configured to control the heating capacity by adjusting the flow rate of the high-temperature working medium in the heater and the variable adjustment mechanism of the flow path and adjusting the heat insulation around the mechanism. A system in which a cooler that cools the working fluid of the engine from a gas to a liquid and condenses is provided in the water heater so that hot water can be generated by heat dissipation.

Images