JP2008088892A - Non-azeotropic mixture medium cycle system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-azeotropic mixture medium cycle system capable of adjusting the concentration of a low boiling point medium in a circulating operating fluid by storing a part of the operating fluid in a liquid phase in a state of the operating fluid being separated into a gas phase and a liquid phase in a power cycle, stably operating by adjusting the concentration with respect to fluctuations in external conditions, and displaying its performance to the maximum. <P>SOLUTION: A concentration adjusting storage part 15 is disposed for storing a part of the liquid phase operating fluid in a liquid phase operating fluid flow passage, a high boiling point medium in the operating fluid circulating in a main flow passage 1a is increased or decreased by controlling the storage amount, and the percentage of each of the mediums in the operating fluid in the main flow passage 1a is made adjustable. Thereby, the concentration of the low boiling point medium in the operating fluid circulating in the main flow passage 1a can be adjusted without an external adjusting equipment, the concentration of the low boiling point medium in the operating fluid can be appropriately adjusted in response to the temperature fluctuations in each heat source, and the entire system can display its performance to the maximum in a stable operating condition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a non-azeotropic mixed medium cycle system that circulates a working fluid, which is a mixed medium of a plurality of substances, while heating and cooling, and obtains motive energy by performing work on the working fluid that repeats phase change, and in particular, circulates. The present invention relates to a non-azeotropic mixed medium cycle system that can adjust the concentration of a low-boiling-point medium that is a main component of a gas-phase working fluid in a working fluid and can be stably operated by adjusting the appropriate concentration.

  When using a steam power cycle, if the temperature difference between the high-temperature heat source and the low-temperature heat source is small, a mixed medium of water and a fluid having a lower boiling point than water in order to increase heat efficiency and effectively convert heat into power Or, a steam power cycle using a mixture of a plurality of types of fluids having different boiling points other than water as a working fluid has been proposed, and as an example of such a conventional non-azeotropic mixed medium cycle system, There is one described in JP-A-7-91361.

  The conventional non-azeotropic mixed medium cycle system includes an evaporator, a turbine, a condenser and a pump as well as a general Rankine cycle as a steam power cycle, and a working fluid heated by the evaporator is a gas phase working fluid. -Liquid separator that separates the liquid-phase working fluid into a liquid-phase working fluid, an absorber that partially absorbs the gas-phase working fluid expanded on the front side of the condenser into the liquid-phase working fluid, and the working fluid heated by the evaporator Among them, a regenerator for exchanging heat between the liquid-phase working fluid and the low-temperature liquid-phase working fluid before exchanging heat with the evaporator, and a high-temperature gas-phase working fluid extracted from the middle of a turbine arranged in multiple stages And a heater that exchanges heat with a low-temperature liquid-phase working fluid.

This conventional non-azeotropic mixed medium cycle system can increase the thermal efficiency as compared with a general Rankine cycle using a single working fluid. The liquid phase working fluid is partially absorbed, and the amount of working fluid that exchanges heat with the low-temperature heat source in the condenser is reduced, thereby reducing the load on the condenser and increasing the overall efficiency and excessively increasing the size of the condenser. And it has the advantage that the cost increase accompanying this can be suppressed.
Japanese Patent Laid-Open No. 7-91361

  The conventional non-azeotropic mixed medium cycle system has a configuration shown in the above-mentioned patent document. Since the working fluid is a mixed medium of a low boiling point medium and a high boiling point medium, the gas separated by the gas-liquid separator is used. The concentration ratio of each medium component differs between the phase working fluid and the liquid phase working fluid. The ratio of each component in the working fluid is almost constant in the steady state, but if the concentration ratio of the working fluid in the main flow path of the cycle changes due to external factors such as changes in the high and low temperature heat sources and changes in the turbine load, the efficiency Will be greatly affected. In particular, when natural energy is used for a high-temperature heat source or a low-temperature heat source, it is clear that these will cause seasonal fluctuations, etc., and the cycle of the working fluid will change due to changes in the temperature of each heat source. There is a problem that the efficiency is deteriorated, for example, the turbine output obtained is difficult to reduce.

  Also, unlike the initial assumption of the system design, when the liquid-phase working fluid is stagnant in the flow path, a part of the liquid-phase working fluid with a low concentration of low boiling point medium is not involved in the cycle. There is also a problem that the concentration of the low boiling point medium in the cycle becomes relatively high, causing a deviation from the design value of the system, resulting in performance degradation.

  However, with regard to such problems, the conventional system has no effective means other than reviewing the flow state of the working fluid in the entire system and performing refurbishment, etc., and it is difficult to quickly and appropriately respond to temporary changes in the situation. It had the problem that.

  The present invention has been made to solve the above-described problems. In a working fluid that stores and circulates part of a liquid-phase working fluid in a state where the working fluid in a power cycle is separated into a gas phase and a liquid phase. To provide a non-azeotropic mixed medium cycle system that makes it possible to adjust the concentration of a low-boiling medium, adjust the concentration to fluctuations in external conditions, enable stable operation, and maximize performance. Objective.

  In the non-azeotropic mixed medium cycle system according to the present invention, a working fluid in which a plurality of fluids having different boiling points are mixed is heat-exchanged with a predetermined high-temperature heat source in a liquid state, and at least a part of the working fluid is evaporated. An evaporator to be used, a gas-liquid separator that separates a high-temperature working fluid obtained by the evaporator into a gas phase component and a liquid phase component, and the gas phase component of the working fluid is introduced and retained by the fluid An expander that converts thermal energy into power, and a gas phase working fluid exiting the expander are combined with the liquid phase exiting the gas-liquid separator to exchange heat with a predetermined low-temperature heat source. In a non-azeotropic mixture cycle system comprising at least a condenser to condense and a compressor for compressing the working fluid exiting the condenser and directing it to the evaporator, a high temperature taken from the gas-liquid separator Part of the working fluid in the flow path of the liquid phase working fluid Those having a density adjustment reservoir by a predetermined amount adjustably reservoir.

  As described above, according to the present invention, in the liquid-phase working fluid flow path that has undergone gas-liquid separation in the system, a part of the working fluid having a high boiling point medium concentration in the liquid phase is stored, and the amount of storage is controlled to control the cycle. By increasing or decreasing the high boiling point medium content in the working fluid circulating in the main flow path connecting the evaporator, the expander, the condenser, and the compressor, the ratio of each medium in the working fluid in the main flow path can be adjusted. When the amount is increased to relatively reduce the high-boiling point medium in the working fluid in the main flow path, the concentration of the low-boiling point medium in the circulating working fluid can be increased. When the amount of high-boiling medium in the working fluid is increased relatively, the concentration of the low-boiling medium of the circulating working fluid can be reduced. , Temperature of each heat source with seasonal change Dynamic and turbine load fluctuation can be adjusted to an appropriate concentration the working fluid in response to changes in the external conditions, is caused to maximize its performance the entire system as a stable operating condition.

  Further, in the non-azeotropic mixed medium cycle system according to the present invention, if necessary, the evaporator is provided with a shell that is a hollow pressure vessel, and a fluid subject to heat exchange at both ends in the longitudinal direction. A heat exchanging portion in which the inflow / outflow port of the fluid is present, and each inflow / outflow port other than the outflow port of the working fluid in the heat exchanging portion extends outside the shell and is isolated from the internal space of the shell. The working fluid outlet in the heat exchange section is in open communication with the shell internal space, and the high-temperature working fluid flowing out from the outlet of the heat exchange section into the shell internal space is separated into the gas phase in the internal space. And separated into a liquid phase component, and a gas-phase working fluid and a liquid-phase working fluid can be separately taken out from the shell, and also serves as the gas-liquid separator. Specified in the shell internal space It is a structure to be fetched adjustably being reservoir by those doubling as the concentration adjusting reservoir.

  As described above, according to the present invention, the evaporator is provided with a heat exchanging part that exchanges heat between the high-temperature heat source and the working fluid, and a shell that surrounds the heat exchanging part. High-temperature mixed-phase working fluid in a state where the vapor phase component evaporated and the other liquid-phase component are mixed after the liquid-phase working fluid is exchanged with the high-temperature heat source in the heat exchange unit. From the heat exchange section into the shell internal space, the mixed-phase working fluid is separated into a gas phase and a liquid phase in this internal space, and the storage amount is adjusted as a concentration adjusting reservoir for the liquid phase working fluid. Since it is possible to store a part of it, the vapor-phase working fluid and the liquid-phase working fluid can be taken out from the evaporator in a separated state, and the evaporator also has the function of a gas-liquid separator. The gas-liquid separator can be omitted, and the evaporator Pressure loss and heat loss can be reduced as compared with other liquid separators, and the space required for equipment layout can be reduced, and the low-boiling medium concentration adjustment of the working fluid corresponding to changes in external conditions saves space for storage. Combined with being able to execute without newly installing, the entire system can be made compact and cost-effective.

  In addition, the non-azeotropic mixed medium cycle system according to the present invention detects the state of a high-temperature heat source to be heat exchanged in the evaporator as necessary, and based on the obtained detection value, the concentration adjustment cycle is detected. It adjusts the storage amount of the working fluid in the storage part.

  As described above, according to the present invention, the state of the high-temperature heat source is detected, the storage amount of the concentration adjusting reservoir is adjusted in accordance with the change in the state, and the concentration of the circulating working fluid is adjusted. The concentration of the working fluid can be adjusted and controlled appropriately according to changes in the state of the fluid. Especially when the amount of heat received by the evaporator decreases due to a temperature drop due to seasonal fluctuations, etc. The concentration can be increased to an appropriate state, the saturation temperature of the working fluid in the evaporator can be lowered to make it easy to evaporate, and a stable operation state can be secured by preventing a decrease in the amount of vapor generated in the evaporator.

  In addition, the non-azeotropic mixed medium cycle system according to the present invention detects the state of a low-temperature heat source to be heat exchanged in the condenser, if necessary, and based on the obtained detection value, the concentration adjustment It adjusts the storage amount of the working fluid in the storage part.

  As described above, according to the present invention, the state of the low-temperature heat source is detected, the storage amount of the concentration adjusting reservoir is adjusted in accordance with the state change, and the concentration of the circulating working fluid is adjusted. The concentration of the working fluid can be adjusted and controlled appropriately according to the state change, especially when the heat dissipation in the condenser decreases due to temperature rise due to seasonal fluctuations, etc. The concentration can be lowered to an appropriate state, the saturation pressure of the working fluid in the condenser can be lowered to lower the expander outlet pressure, and the pressure difference between the front and back of the expander can be prevented from decreasing to prevent the output from decreasing.

(First embodiment of the present invention)
Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic system diagram of a non-azeotropic mixed medium cycle system according to the present embodiment.

  In FIG. 1, the non-azeotropic mixed medium cycle system 1 according to the present embodiment exchanges heat between a working fluid composed of a mixed medium of ammonia and water and the warm seawater as the high-temperature heat source, thereby obtaining steam of the working fluid. An evaporator 10, a gas-liquid separator 11 that separates the working fluid into a gas phase component and a liquid phase component, a turbine 12 as the expander that is operated by the gas phase working fluid, and the gas that has left the turbine 12 The gas-liquid separator 11 is separated by a condenser 13 that condenses the working fluid of the phase into a liquid phase, a pump 14 that serves as the compressor that extracts the working fluid from the condenser 13 and introduces it into the evaporator 10. A concentration adjusting reservoir 15 that partially stores a liquid-phase working fluid is provided. Among these, the turbine 12 and the pump 14 are known devices similar to those used in a general steam power cycle, and the description thereof is omitted.

  The evaporator 10 is a general plate heat exchanger in which a plurality of rectangular plates are overlapped and integrated, and working fluid flows through every other gap between the internal plates, while the remaining gaps This is a known configuration in which warm seawater as a high-temperature heat source circulates and two fluids exchange heat via each plate, and detailed description thereof is omitted. One end of the evaporator 10 in the longitudinal direction is connected to a pipe of the main flow path 1a connected to the outlet of the pump 14, and the other end is connected to a pipe communicating with the gas-liquid separator 11 inlet side. The pipes for inflow and outflow are respectively connected.

  In this evaporator 10, the working fluid that is heated by heat exchange with warm seawater while receiving the supply pressure from the pump 14 evaporates a part (a large amount of ammonia that tends to volatilize) evaporates. It becomes a gas-liquid mixed phase state. The flow rate of the working fluid is set so that the working fluid flows out from the evaporator 10 toward the gas-liquid separator 11 in a gas-liquid mixed phase when the temperature is raised to a predetermined temperature.

  The gas-liquid separator 11 is a known device that divides a working fluid that has become a high-temperature gas-liquid mixed phase through heat exchange with warm seawater in the evaporator 10 into a gas phase component and a liquid phase component. The detailed explanation is omitted. The working fluid is divided into a gas phase component and a liquid phase component in the gas-liquid separator 11, and the gas phase working fluid is directed to the turbine 12 through a pipe communicating with the turbine 12 inlet side, while the concentration adjusting reservoir 15. The liquid-phase working fluid is directed to the concentration adjusting reservoir 15 through a pipe communicating with the reservoir.

  Like the evaporator 10, the condenser 13 is a general plate type heat exchanger in which a plurality of plates are overlapped and integrated, and the turbine 12 and the concentration adjustment are performed every other gap between the internal plates. It is known that the working fluid is communicated simultaneously with the respective outlets of the reservoir 15 and the working fluid flows through the gap, while the cold seawater as a low-temperature heat source flows through the remaining gap, and the two fluids exchange heat through the plates. The detailed description is omitted. A gas phase working fluid exiting the turbine 12 and a liquid phase working fluid exiting the concentration adjusting reservoir 15 are simultaneously introduced into the condenser 13, and these are cooled by exchanging heat with cold seawater. The gas-phase working fluid is condensed and part of the gas-phase working fluid is absorbed by the liquid-phase working fluid. At the subsequent stage of the condenser 13, a tank 16 for temporarily storing the liquid-phase working fluid exiting the condenser 13 and sending it to the pump 14 side is disposed.

  The concentration adjusting reservoir 15 is disposed in the branch flow path 1b on the rear stage side of the gas-liquid separator 11, stores a part of the liquid-phase working fluid, and sends the remaining part to the condenser 13 on the rear stage side. Is. The concentration adjusting reservoir 15 is configured to change the liquid surface position, that is, the amount of storage, by adjusting the height at which the working fluid overflows in the storage portion for storing a predetermined amount of working fluid. In the branch flow path 1b from the gas-liquid separator 11 to the condenser 13, the flow rate of the liquid-phase working fluid having a low boiling point medium concentration different from that of the working fluid in the main flow path 1a is based on the storage amount adjustment in the concentration adjusting storage section 15. Therefore, the concentration of each medium in the working fluid can be adjusted and controlled by the main flow path 1a, and the concentration of the low boiling point medium can be adjusted with respect to various external influences such as the temperature change of the high temperature heat source and the low temperature heat source. It is a mechanism that can do. Although omitted in the present embodiment, the liquid-phase working fluid is condensed in the branch channel 1b between the concentration adjusting reservoir 15 and the condenser 13 as in the conventionally known non-azeotropic mixture power cycle. A pressure reducing valve for reducing the pressure to an appropriate pressure before reaching 13 may be provided.

  Next, the cycle execution state of the non-azeotropic mixed medium cycle system according to the present embodiment will be described. As a premise, cold seawater as a low temperature heat source is taken from a predetermined depth position of the sea, and warm seawater as a high temperature heat source is taken from the surface of the sea while securing a predetermined flow rate, respectively, and the condenser 13 or the evaporator 10 Are introduced respectively.

  In the evaporator 10, heat exchange is performed between warm seawater as a high-temperature heat source and all liquid-phase working fluid. A part of the working fluid heated by this heat exchange evaporates as the temperature rises and enters a gas-liquid mixed phase state. This high-temperature working fluid in a mixed phase goes out of the evaporator 10 and reaches the gas-liquid separator 11. In the gas-liquid separator 11, the working fluid is divided into a gas phase component and a liquid phase component, but the gas phase working fluid has a concentration of ammonia as a low boiling point medium as compared with the working fluid before the introduction of the evaporator 10. On the other hand, the liquid working fluid separated from this is not only a gas working fluid but also has a lower ammonia concentration than the liquid working fluid before the introduction of the evaporator. Yes. The gas-phase working fluid exiting the gas-liquid separator 11 travels through the main flow path 1a to the turbine 12, and the liquid-phase working fluid enters the branch flow path 1b from the gas-liquid separator 11 and stores the concentration adjusting reservoir. 15 is introduced.

  When the gas-phase working fluid reaches the turbine 12, it is operated, and the turbine 12 drives other equipment such as a generator to convert the heat energy into usable energy. The gas-phase working fluid that has been expanded and worked in the turbine 12 in this manner is in a state in which the pressure and temperature are lowered, and after exiting the turbine 12, is introduced into the condenser 13.

  On the other hand, the concentration adjusting reservoir 15 stores a predetermined amount of the introduced liquid-phase working fluid while adjusting the storage amount, and the remaining liquid-phase working fluid flows out to the subsequent stage. The liquid phase working fluid exits the concentration adjusting reservoir 15, then goes to the condenser 13, and is introduced into the condenser 13 together with the gas phase working fluid exiting the turbine 12.

  In the condenser 13, the gas-phase working fluid introduced into the condenser 13 and the liquid-phase working fluid also introduced into the condenser 13 are heat-exchanged with cold seawater having a low temperature introduced in a gap across the plate, and the entire working fluid As the gas is cooled, the gas-phase working fluid comes into contact with the liquid-phase working fluid, and is partially absorbed therein to change into the liquid phase. The remaining unabsorbed gas phase working fluid condenses into a liquid phase as it is cooled by heat exchange. The working fluid in the liquid phase is discharged from the condenser 13 to the outside and flows into the tank 16 on the rear stage side.

  The working fluid in the tank 16 returns to the initial ratio of the working fluid in the initial state before entering the evaporator, that is, the ratio of ammonia to water in the working fluid. The liquid phase working fluid has the lowest temperature and pressure in the system. All the liquid-phase working fluid that has reached the tank 16 travels through the main flow path 1 a toward the evaporator 10 via the pump 14. When returning to the evaporator 10, each process after the heat exchange in the evaporator 10 is repeated as described above.

  With respect to this working fluid, the cold seawater used for heat exchange in the condenser 13 is heated to a predetermined temperature by receiving heat from the working fluid. The seawater is discharged out of the condenser 13 and finally discharged into the sea outside the system. In addition, warm seawater whose temperature has decreased due to heat exchange with the working fluid in the evaporator 10 is also released into the sea outside the system after heat exchange.

  Next, the low boiling point medium concentration adjustment state in the working fluid of the non-azeotropic mixed medium cycle system according to the present embodiment will be described. The concentration adjusting reservoir 15 controls the storage amount of the liquid-phase working fluid, and the ratio of the working fluid having a high ratio of water as a high boiling point medium to the concentration adjusting reservoir 15 in the working fluid of the entire system. As a result, the concentration of the working fluid circulating in the main flow path 1a is changed.

  The maximum storage amount in the concentration adjusting storage portion 15 is desirably a ratio of about “1− (composition ratio of low boiling point medium to the whole fluid)” in the total amount of circulating working fluid. For example, when the composition ratio of the low boiling point medium is 0.8, the storage amount is 0.2, that is, about 20% of the whole. This is because the lower the initial low-boiling-point medium concentration before the adjustment in the circulating working fluid is, the smaller the adjustment effect is unless the storage amount in the concentration adjustment storage unit 15 is changed greatly. In other words, when the ammonia concentration of the low boiling point medium is low, the proportion of water that is the high boiling point medium is high, and the influence on the whole is small even if the amount of stored water is slightly changed.

  In the concentration adjusting reservoir 15, when the storage amount of the liquid phase working fluid having a low ammonia concentration of the low boiling point medium and a high proportion of water being the high boiling point medium is increased, the proportion of water in the working fluid circulating in the main flow path 1a. Decreases, and the ammonia concentration of the circulating working fluid can be increased. When the concentration of ammonia increases, in the evaporator 10, when the pressure is constant, the saturation temperature (boiling start temperature) of the working fluid decreases, and the amount of the gas phase working fluid increases accordingly, and the amount of the liquid phase working fluid decreases. Decrease. In response to this, the gas-liquid separator 11 increases the amount of the gas-phase working fluid after the separation, and decreases the amount of the liquid-phase working fluid. On the other hand, in the condenser 13, since the amount of the gas-phase working fluid increases, it flows as a working fluid having a high ammonia concentration, and the saturation pressure rises at the same condensation temperature.

  On the other hand, when the storage amount of the liquid phase working fluid having a low ammonia concentration and a high proportion of water is reduced in the concentration adjusting reservoir 15, the proportion of water in the working fluid circulating in the main flow path 1 a is increased. The ammonia concentration in the working fluid can be reduced. When the concentration of ammonia decreases, in the evaporator 10, the saturation temperature (boiling start temperature) of the working fluid rises, and accordingly, the amount of the gas phase working fluid decreases and the amount of the liquid phase working fluid increases. In response to this, the gas-liquid separator 11 decreases the amount of the gas-phase working fluid after the separation, and increases the amount of the liquid-phase working fluid. On the other hand, in the condenser 13, since the amount of the gas-phase working fluid decreases, the condenser 13 flows in as a working fluid having a low ammonia concentration, and the saturation pressure decreases at the same condensation temperature.

  Specifically, while constantly detecting the temperature, flow rate, and other conditions of warm seawater, which is a high-temperature heat source, it is detected when the water temperature decreases due to seasonal changes from summer to winter and the amount of heat received by the evaporator decreases. Based on the value, the storage amount in the concentration adjusting reservoir 15 is increased, the ammonia concentration of the circulating working fluid is increased, and the saturation temperature (boiling start temperature) of the working fluid is lowered, thereby generating steam generated in the evaporator. A decrease in the amount can be prevented. In addition, while constantly detecting the temperature and flow rate of cold seawater, which is a low-temperature heat source, when the water temperature rises due to seasonal fluctuations and the amount of heat released from the condenser decreases, the concentration adjustment reservoir is based on the detected value. The pressure difference between the turbine 12 outlet and the inlet is reduced by reducing the storage amount in the section 15, lowering the ammonia concentration of the circulating working fluid, and lowering the saturation pressure (condensing pressure) of the working fluid. This can prevent the decrease in turbine output.

  Thus, by adjusting the working fluid to an appropriate concentration in response to temperature fluctuations of each heat source and turbine load fluctuations, the entire system can be brought into a stable operating state, and the system performance can be maximized. In addition, when a part of the closed pipe constituting the system is opened at the time of maintenance, the high boiling point medium is mainly discharged to the outside. The concentration of the working fluid flowing through can be adjusted to an appropriate state.

  As described above, in the non-azeotropic mixed medium cycle system according to the present embodiment, the liquid phase is high in the branch flow path 1b that is the flow path of the liquid-phase working fluid that has undergone gas-liquid separation in the gas-liquid separator 11. In the working fluid circulating in the main flow path 1a of the cycle, a concentration adjusting reservoir 15 for storing a part of the working fluid having a high boiling point medium concentration is disposed, and the storage amount in the concentration adjusting reservoir 15 is controlled. Since the ratio of each medium forming the working fluid can be adjusted by increasing / decreasing the high-boiling medium content, when the storage amount is increased to relatively reduce the water in the working fluid in the main channel 1a, When the ammonia concentration of the working fluid in the passage 1a can be increased, and when the amount of storage is reduced to relatively increase the water in the working fluid in the main passage 1a, the ammonia concentration of the working fluid in the main passage 1a Can be reduced However, the concentration of the working fluid can be adjusted without an external adjustment device, and the working fluid can be adjusted to an appropriate concentration in response to changes in external conditions such as temperature fluctuations of each heat source and turbine 12 load fluctuations accompanying seasonal changes. The entire system can be operated in a stable operating state, such as maintaining the amount of steam generated, and its performance can be maximized.

  In the non-azeotropic mixed medium cycle system according to the above-described embodiment, a plate-type heat exchanger is used as the evaporator 10 and the condenser 13, but the present invention is not limited to this, and heat exchange is performed at the end in the longitudinal direction. As long as the inlet / outlet of the target fluid is located, another type of heat exchanger such as a shell and tube type may be adopted.

  In the non-azeotropic mixed medium cycle system according to the embodiment, the vapor phase working fluid is condensed by the condenser 13 and part of the vapor phase working fluid is absorbed by the liquid phase working fluid. However, the present invention is not limited to this, and a separate absorber is provided on the upstream side of the condenser, and a part of the gas-phase working fluid from the turbine is absorbed by the liquid-phase working fluid introduced from the concentration adjusting reservoir. It is also possible to adopt a configuration in which the working fluid is collectively introduced from the absorber in a mixed phase of the gas phase and the liquid phase into the condenser, and the gas phase is mainly condensed in the condenser.

  In the non-azeotropic mixed medium cycle system according to the above-described embodiment, the liquid-phase working fluid separated from the gas-phase working fluid by the gas-liquid separator 11 is directly introduced to the concentration adjusting reservoir 15, and the liquid-phase working fluid is A part of the working fluid is stored. However, the present invention is not limited to this, and as shown in FIG. 2, a regenerator 17 is provided on the upstream side of the concentration adjusting reservoir 15 and introduced into the concentration adjusting reservoir 15. The liquid-phase working fluid before being heated and the working fluid just before entering the evaporator 10 can be configured to exchange heat, and the energy of the liquid-phase working fluid exiting the gas-liquid separator 11 can be stored. By collecting with the regenerator 17, the thermal efficiency of the cycle can be further improved. The regenerator is provided on the rear side of the concentration adjusting reservoir 15, and heat exchange is performed between the liquid-phase working fluid delivered from the concentration adjusting reservoir 15 and the working fluid immediately before entering the evaporator 10. It does not matter as a configuration to be made.

(Second embodiment of the present invention)
A second embodiment of the present invention will be described with reference to FIGS. 3 is a schematic system diagram of the non-azeotropic mixed medium cycle system according to the present embodiment, FIG. 4 is a schematic longitudinal sectional view of an evaporator in the non-azeotropic mixed medium cycle system according to the present embodiment, and FIG. 5 is the present embodiment. It is heat exchange part structure explanatory drawing of the evaporator in the non-azeotropic mixed-medium cycle system which concerns on this.

  In each of the drawings, the non-azeotropic mixed medium cycle system 2 according to the present embodiment includes an evaporator 20, turbines 23 and 24, a condenser 25, and a pump 26, as in the first embodiment. As a different point, the regenerator 27 for exchanging heat of the liquid-phase working fluid with all the liquid-phase working fluid that has come out of the condenser 25 out of the working fluid that has become high temperature through heat exchange in the evaporator 20; And a heater 28 for exchanging heat between a part of the gas-phase working fluid extracted at the stage of exiting the first-stage turbine 23 and the liquid-phase working fluid. It has the structure which has the function of the liquid separator and the concentration adjusting reservoir. Among these, the turbines 23 and 24 and the pump 26 are known devices similar to those used in a general steam power cycle, and the description thereof will be omitted.

  The evaporator 20 has a hollow shell 21 that forms an outermost shell and is connected to other devices by piping, and a plate type that is disposed inside the shell 21 and exchanges heat between warm seawater as a high-temperature heat source and a working fluid. The heat exchange part 22 is provided.

  The shell 21 is a general substantially cylindrical capsule-shaped hollow pressure vessel having a warm seawater inlet 21a and a working fluid outlet 21c at one end in the longitudinal direction, and a warm seawater outlet 21b and a working fluid inlet 21e at the other end. Each of the working fluid outlets 21d is configured to be connectable to an external pipe, and the inside and the outside are separated in a watertight state except for these inlets and outlets. The working fluid inlet 21e of the shell 21 is connected to a pipe communicating with the regenerator 27 low temperature side. The working fluid outlet 21c is connected to a pipe communicating with the inlet side of the turbine 23, and the working fluid outlet 21d is connected to a pipe communicating with the regenerator 27 high temperature side. The inner space 21f of the shell 21 is in a heat-retaining state with respect to the outside, and a perforated partition plate 21g is provided in the shell 21 to support the heat exchanging portion 22 and further ensure the separation of gas and liquid. It is done.

  The heat exchanging unit 22 is a general plate heat exchanger in which a plurality of plates 50 are overlapped and integrated, and every other gap between the internal plates 50 has a working fluid circulation portion and warm seawater. This is a known configuration in which the two fluids exchange heat through the respective plates 50, and detailed descriptions thereof are omitted. The heat exchanging portion 22 has a warm seawater inlet 22a and a working fluid outlet 22b at one end in the longitudinal direction, and a warm seawater outlet (not shown) and a working fluid inlet 22c at the other end, respectively. These inflow / outflow ports in the heat exchanging part 22 are integrated with the inflow / outflow ports of the shell 21 except for the outflow port 22b of the working fluid. It is the structure isolated in the watertight state with respect to the space 21f. On the other hand, the working fluid outlet 22b is open in the inner space 21f of the shell 21 and communicates with the inner space 21f and the working fluid outlets 21c and 21d.

  The working fluid that is heated by heat exchange with warm seawater while receiving the supply pressure from the pump 26 in the heat exchange section 22 rises up the heat exchange section 22 and a part thereof (a volatile ammonia is large). Occupies a part) and evaporates into a gas-liquid mixed phase. The flow rate is set so as to flow out in a gas-liquid mixed phase state from the outlet 22b at the top of the heat exchanging section 22 at the stage where the temperature has been raised to a predetermined temperature.

  The working fluid flows out from the outlet 22b of the heat exchanging section 22 into the internal space 21f of the shell 21, and then flows into the gas phase and the liquid phase while flowing down the internal space 21f. From the upper working fluid outlet 21c to the rear turbine 23, the liquid-phase working fluid reaches the lower portion of the shell 21 and is stored, and then from the working fluid outlet 21d to the rear regenerator 27. As a result, the high-temperature working fluid that has undergone heat exchange with warm seawater is divided into a gas phase component and a liquid phase component, and can be taken out of the shell 21.

  In the lower part of the shell 21, a part of the liquid-phase working fluid is stored. A mechanism for adjusting the height at which the working fluid overflows in the storage part to change the liquid level position, that is, the storage amount. It has become. The concentration of each medium in the working fluid can be adjusted and controlled in the main flow path 2a as a result by increasing or decreasing the ratio of the working fluid having a high water ratio as the high boiling point medium among the working fluid in the entire system. It is possible to cope with various external influences such as temperature changes of the high temperature heat source and the low temperature heat source by adjusting the concentration of the low boiling point medium of the working fluid.

  As in the first embodiment, the condenser 25 is a general plate heat exchanger in which a plurality of plates are overlapped and integrated. It is known that the working fluid communicates simultaneously with the outlets of the regenerator 27 and the working fluid flows through the gap, while cold seawater as a low-temperature heat source circulates through the remaining gap, and the two fluids exchange heat through the plates. This is a configuration, and detailed description thereof is omitted. A gas phase working fluid exiting the turbine 24 and a liquid phase working fluid exiting the regenerator 27 are simultaneously introduced into the condenser 25, and these are cooled by exchanging heat with cold seawater. The working fluid is condensed, and a part of the gaseous working fluid is absorbed by the liquid working fluid. A tank 29 that temporarily stores the liquid-phase working fluid exiting the condenser 25 and sends it to the pump 26 side is disposed at the subsequent stage of the condenser 25.

  The regenerator 27 is interposed in the main flow path 2a of all liquid phase working fluid from the condenser 25 through the pump 26 to the evaporator 20, and all liquid phase working fluid before reaching the evaporator 20; It is a heat exchanger that exchanges heat with a high-temperature liquid-phase working fluid that has been separated from the gas-phase working fluid in the evaporator 20 and exits the evaporator 20, and the heat-exchange unit 22 and the condenser 25 of the evaporator 20. Similarly, it is a general plate heat exchanger in which a plurality of plates are stacked and integrated, and detailed description thereof is omitted. In this regenerator 27, the branch flow path 2b on the high-temperature liquid-phase working fluid side leading to the working fluid outlet 21d of the evaporator 20 is connected to the condenser 25 via the pressure reducing valve 27a. The liquid phase working fluid is introduced into the condenser 25 after the pressure is adjusted via the pressure reducing valve 27a.

  Like the regenerator 27, the heater 28 is interposed in the main flow path 2 a of all the liquid phase working fluid from the condenser 25 to the evaporator 20, and the regenerator 27 is located at a position upstream of the regenerator 27. Is a heat exchanger for exchanging heat between all the liquid-phase working fluid before reaching the first stage and a part of the high-temperature gas-phase working fluid extracted after leaving the first stage turbine 23, and the evaporator 20 The heat exchanger 22 and the condenser 25 are the same plate type heat exchanger, and detailed description thereof is omitted. In the branch channel 2c on the high temperature working fluid side connected to the outlet side of the turbine 23 of the heater 28, the pressure for smoothly flowing the high temperature working fluid into and out of the heater 28 in the portion on the rear stage side from the heater 28. And a tank 62 for reducing the influence of changes in the flow rate of the working fluid associated with the pump operation.

  The branch flow path 2 c on the high temperature working fluid side of the heater 28 is joined via the tank 62 and the pump 61 to a position on the downstream side of the heater 28 and on the upstream side of the regenerator 27 in the main flow path 2 a. A system in which the working fluid that is connected by piping and exits the turbine 23 and is cooled and condensed by heat exchange in the heater 28 passes through the tank 62 and the pump 61 and is added to the liquid-phase working fluid immediately before reaching the regenerator 27. It is. The tank 62 and the pump 61 have no problem as long as they have a capacity and a discharge capacity sufficient to allow the liquid-phase working fluid condensed in the heater 28 to flow to the subsequent stage without backflow from the main flow path 2a. A small one with reduced capacity can be used.

  Next, the cycle execution state of the non-azeotropic mixed medium cycle system according to the present embodiment will be described. As a premise, cold seawater as a low-temperature heat source is taken from a predetermined depth position of the sea, and warm seawater as a high-temperature heat source is taken from the surface of the sea while securing a predetermined flow rate, respectively, and the condenser 25 or the evaporator 20 Are introduced respectively.

  In the evaporator 20, warm seawater introduced from the upper warm seawater inlet 21 a as a high-temperature heat source and all liquid-phase working fluid introduced from the lower working fluid inlet 21 e are exchanged by the internal heat exchange unit 22. Heat exchange. Part of the working fluid heated here evaporates as the temperature rises, and enters a gas-liquid mixed phase state. This mixed-phase high-temperature working fluid flows out from the outlet 22b of the heat exchange part 22 into the internal space 21f of the shell 21, passes through the perforated partition plate 21g, and runs along the side surface of the heat exchange part 22 and the inner wall of the shell 21. In the process of flowing down, it is divided into a gas phase component and a liquid phase component, and the gas phase working fluid ascends the internal space 21f and exits from the evaporator 20 through the working fluid outlet 21c above the shell 21. Further, the liquid-phase working fluid flows down as it is and reaches the lower part of the shell 21 that also serves as a concentration adjusting reservoir.

  In the lower part of the shell 21 as the concentration adjusting reservoir, as in the first embodiment, the storage amount of the liquid-phase working fluid is controlled, and the ratio of the working fluid having a high water ratio is increased or decreased. As a result, the concentration of the working fluid circulating in the main flow path 2a can be changed. By adjusting the working fluid to an appropriate concentration in response to temperature fluctuations of each heat source and turbine load fluctuations, the entire system can be operated stably. The system performance can be maximized. Thus, at the lower part of the shell 21, a part of the liquid-phase working fluid is stored while adjusting the storage amount, and the remaining liquid-phase working fluid flows out of the evaporator 20 from the working fluid outlet 21d. .

  The high-temperature gas-phase working fluid exiting the evaporator 20 has a very high proportion of ammonia, which is a low boiling point medium, as compared to the liquid-phase working fluid having an initial composition before the introduction of the evaporator 20. Reaches the turbines 23 and 24 to operate them, and the turbines 23 and 24 drive other devices such as a generator to convert the heat energy into usable energy. The gas phase working fluid that has been expanded and worked in the turbines 23 and 24 is in a state in which the pressure and temperature are reduced, and after exiting the second stage turbine 24, is introduced into the condenser 25.

  On the other hand, the high-temperature liquid-phase working fluid that has flowed out of the evaporator 20 from the working fluid outlet 21d of the evaporator 20 has a lower ammonia ratio than the liquid-phase working fluid having the initial composition before the evaporator 20 is introduced. It has become. This high-temperature liquid-phase working fluid enters the branch channel 2 b communicating with the lower part of the shell 21 and is introduced into the regenerator 27. In this regenerator 27, all the liquid phase working fluid passing through the other main flow path 2a and the high-temperature liquid phase working fluid are subjected to heat exchange, and the temperature of all the liquid phase working fluid on the main flow path 2a side is raised to evaporate. Turn to the container 20 side. The liquid-phase working fluid on the side of the branch flow path 2b cooled by heat exchange in the regenerator 27 exits the regenerator 27 and is then introduced into the condenser 25 through the pressure reducing valve 27a.

  In the condenser 25, the gas-phase working fluid introduced into the condenser 25 and the liquid-phase working fluid also introduced into the condenser 25 are heat-exchanged with cold seawater having a low temperature introduced in a gap across the plate, and the whole working fluid As the gas is cooled, the gas-phase working fluid comes into contact with the liquid-phase working fluid, and is partially absorbed therein to change into the liquid phase. The remaining unabsorbed gas phase working fluid condenses into a liquid phase as it is cooled by heat exchange. The working fluid in the liquid phase is discharged from the condenser 25 to the outside and flows into the tank 29 on the rear stage side.

  The working fluid in the tank 29 has the lowest temperature and pressure in the system as a liquid-phase working fluid. The liquid-phase working fluid that has reached the tank 29 travels through the main flow path 2 a toward the evaporator 20 via the pump 26.

  Part of the high-temperature gas-phase working fluid (about 1%) from the first-stage turbine 23 to the second-stage turbine 24 is extracted and enters the branch flow path 2c and introduced into the heater 28. Is done. The heater 28 exchanges heat between all the liquid-phase working fluid passing through the other main flow path 2a and the extracted high-temperature gas-phase working fluid, and raises the temperature of all the liquid-phase working fluid. The heat that the working fluid has is recovered. The gas-phase working fluid is cooled through heat exchange in the heater 28 and condensed into a liquid phase. The condensed liquid-phase working fluid exits the heater 28 and is then connected to the tank 62 and the pump 61. After that, all the liquid phase working fluid flowing through the main flow path 2a at the junction of the branch flow path 2c and the main flow path 2a is added. At this merging point, all the working fluids divided into the plurality of flow paths in each process are combined together, and the ratio of ammonia and water in the working fluid returns to the initial ratio.

  In this way, the liquid-phase working fluid passes through heat exchange in the heater 28 and the regenerator 27, returns to the evaporator 20 in a state where the temperature is raised to a predetermined temperature in advance, and after the heat exchange in the evaporator 20 as described above. Each process will be repeated.

  With respect to this working fluid, the cold seawater used for heat exchange in the condenser 25 is heated to a predetermined temperature by receiving heat from the working fluid. This seawater is discharged out of the condenser 25 and finally discharged into the sea outside the system. In addition, warm seawater whose temperature has decreased due to heat exchange with the working fluid in the evaporator 20 is also released into the sea outside the system after heat exchange.

  Thus, in the non-azeotropic mixed medium cycle system according to the present embodiment, the evaporator 20 surrounds the heat exchange unit 22 that exchanges heat between the high-temperature heat source and the working fluid, and the heat exchange unit 22. The shell 21 is provided, and the internal space 21f of the shell 21 is communicated with the working fluid outlet 22b in the heat exchanging portion 22, and the heat exchanging portion 22 exchanges heat between the liquid working fluid and the high-temperature heat source, and then evaporates. When the high-temperature mixed-phase working fluid in a state in which the vapor phase component and the other liquid phase components are mixed flows out from the heat exchanging portion 22 to the internal space 21f of the shell, the mixed-phase working fluid is gasified in the internal space 21f. The liquid phase working fluid is separated into a phase component and a liquid phase component, and a part of the liquid phase working fluid can be stored as a concentration adjusting reservoir so that the storage amount can be adjusted. It Thus, the evaporator 20 has the function of a gas-liquid separator, so that a gas-liquid separator separate from the evaporator can be omitted, and the pressure loss is lower than when the evaporator and the gas-liquid separator are separate. In addition to reducing heat and heat loss, the space required for equipment layout can be reduced, and the low-boiling-point concentration adjustment of working fluid in response to changes in external conditions can be performed without newly creating a storage space. The whole system can be made compact and low cost.

  In the non-azeotropic mixed medium cycle system according to each of the first and second embodiments, the working fluid formed of a mixed medium of ammonia and water exchanges heat with warm seawater, and the generated gas phase operation is performed. Although an example of a steam power cycle is shown in which the process of operating the turbine with a fluid and repeating the process of making the gas phase working fluid exiting the turbine heat-exchanged with cold seawater to form a liquid phase is not limited to this, It can also be applied to other cycles such as a refrigeration cycle. Also, another mixed medium is used as the working fluid, another heat source such as an industrial process fluid such as process gas or steam is used as the high-temperature heat source, or other cooling water is used as the low-temperature heat source. Or a gas for cooling may be used.

1 is a schematic system diagram of a non-azeotropic mixed medium cycle system according to a first embodiment of the present invention. It is a schematic system diagram of the other example in the non-azeotropic mixed-medium cycle system which concerns on the 1st Embodiment of this invention. It is a schematic system diagram of the non-azeotropic mixed medium cycle system according to the second embodiment of the present invention. It is a schematic longitudinal cross-sectional view of the evaporator in the non-azeotropic mixed-medium cycle system which concerns on the 2nd Embodiment of this invention. It is heat exchange part structure explanatory drawing of the evaporator in the non-azeotropic mixed-medium cycle system which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

1, 2 Non-azeotropic mixed medium cycle system 1a, 2a Main flow path 1b, 2b, 2c Branch flow path 10, 20 Evaporator 11 Gas-liquid separator 12, 23, 24 Turbine 13, 25 Condenser 14, 26, 61 Pump 15 Concentration adjusting reservoir 16, 29, 62 Tank 17 Regenerator 21 Shell 21a Warm seawater inlet 21b Warm seawater outlet 21c, 21d Working fluid outlet 21e Working fluid inlet 21f Internal space 21g Perforated partition plate 22 Heat exchanger 22a, 22c Inlet 22b Outlet 27 Regenerator 27a Pressure reducing valve 28 Heater 50 Plate

Claims (4)

A working fluid in which a plurality of fluids having different boiling points are mixed is subjected to heat exchange with a predetermined high-temperature heat source in a liquid state, and at least a part of the working fluid is evaporated, and the high temperature obtained by the evaporator A gas-liquid separator that separates the working fluid into a gas phase component and a liquid phase component, an expander that introduces the gas phase component of the working fluid and converts thermal energy held by the fluid into power, and the expansion The vapor phase working fluid exiting the machine is combined with the liquid phase component exiting the gas-liquid separator to exchange heat with a predetermined low-temperature heat source, and the vapor phase component is condensed, and the operation exiting the condenser A non-azeotropic mixture cycle system comprising at least a compressor for compressing fluid toward the evaporator;
A non-azeotropy is provided in the flow path of the high-temperature liquid-phase working fluid taken out from the gas-liquid separator, and a concentration-adjusting reservoir for storing a part of the working fluid so that a predetermined amount can be adjusted. Mixed media cycle system. The non-azeotropic mixed medium cycle system according to claim 1,
The evaporator includes a shell that is a hollow pressure vessel, and a heat exchanging unit that is disposed in the shell and has an inlet / outlet of a fluid to be heat exchanged at both longitudinal ends, and operates in the heat exchanging unit. Each inflow / outlet other than the fluid outflow port extends outside the shell and is isolated from the shell internal space, while the working fluid outflow port in the heat exchanging portion is in open communication with the shell internal space The high-temperature working fluid flowing out from the outlet of the heat exchange section into the shell internal space is separated into a gas phase component and a liquid phase component in the internal space, and the gas phase working fluid and the liquid phase are separated from the shell. The working fluid can be separately taken out and serves as the gas-liquid separator, and the separated liquid-phase working fluid is taken out while being stored in the shell internal space so that a predetermined amount can be adjusted. The concentration adjustment reservoir Non-azeotropic mixed medium cycle system, characterized in that also serves as a. In the non-azeotropic mixed medium cycle system according to claim 1 or 2,
A state of a high-temperature heat source that is a heat exchange target in the evaporator is detected, and a storage amount of the working fluid in the concentration adjusting storage portion is adjusted based on the obtained detection value. Mixed media cycle system. In the non-azeotropic mixed medium cycle system according to claim 1 or 2,
A state of a low-temperature heat source that is a heat exchange target in the condenser is detected, and a storage amount of the working fluid in the concentration adjusting reservoir is adjusted based on the obtained detection value. Mixed media cycle system.

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