KR101487829B1 - High efficiency power generation cycle - Google Patents

Abstract

A high efficiency power generation cycle is disclosed. The high efficiency power generation cycle of the present invention comprises: a power generator which generates electricity by operating a turbine with a refrigerant or water as a thermal medium and includes the turbine and a generator; a condenser to absorb the heat of the thermal medium and condense the heat; an evaporator to supply the heat to the thermal medium and evaporate the thermal medium; a compressor to compress and transfer the thermal medium; and a heat exchanger to heat the thermal medium by gas of high pressure with an outer heat source in order to operate the turbine. The thermal medium is heated in the heat exchanger after being evaporated in the evaporator. According to the present invention, the provided high efficiency power generation cycle is configured to minimize a heat loss due to the vaporization latent heat with a second cycle line.

Description

HIGH EFFICIENCY POWER GENERATION CYCLE

The present invention relates to a high-efficiency power generation cycle, and more particularly, to a high-efficiency power generation cycle in which a coolant or water is used as a heat medium to be evaporated at a low temperature and a low pressure and heat is heat- The present invention relates to a high-efficiency power generation cycle in which electricity can be generated and generated by thermal energy as a technology of using renewable energy of an indirect heating heat exchange type.

As a new energy and renewable energy utilization technology, existing cycle is divided into 'organic Rankine cycle' using Rankine cycle using steam turbine and 'regenerative brake cycle' applying brake cycle using gas turbine. There are 'Kalina Cycle' and 'Binary Cycle' which utilize low-temperature heat sources that are being actively studied as a way to utilize renewable energy. It can be divided into 'low-temperature heat source combined cycle' which improves the efficiency of the organic Rankine cycle, but all belong to the organic Rankine cycle.

Steam turbine power generation, which generates steam by heating water directly, is called the Rankine cycle, a basic thermodynamic fundamental cycle named by Dr. Walrim John Matthew Rankin of Scotland, which is represented by thermal and nuclear power generation, Of the total population. This Rankine cycle forms a cycle cycle of compression (feed pump), evaporation (steam generator such as boiler), expansion (generator), and condensation (condenser).

The 'Braaten cycle', which is the combustion of gas into high pressure air to generate gas turbine, was developed by Dr. Brayton of the United States. The regenerative brake cycle consists of compression, heating (evaporation), expansion (power generation) .

The 'Kalina Cycle' was designed by Dr. Kalina in the US in 1980. It can be used for compressing, first heat exchange (first low temperature), second heat exchange (second high temperature), evaporation (external heat source supply), expansion And the organic Rankine cycle refers to a cycle that cycles through compression, evaporation (external heat source supply), expansion (power generation), and condensation.

In addition, the 'low-temperature heat source combined cycle' is an organic Rankine cycle in which compression, evaporation, expansion, and condensation are connected to each other, and the binary cycle, which is mainly used for geothermal heat, is a cycle in which the two boiling high and low- Organic Rankine cycle.

All of the above-mentioned cycles are characterized by compression, evaporation, expansion and condensation. Patent documents related to this are Korean Patent Registration Nos. 1236070, 766101, 1249188 and 1188335.

As a technology of using renewable energy, a cycle that generates electric energy by heat is a four-step Karono cycle, which is an abnormal cycle of a heat engine. The refrigeration cycle consists of compression, evaporation, expansion and condensation. , Expansion, and evaporation.

Since the evaporator is supplied with a heat source from outside and evaporates while changing from liquid to gas, it requires a high-temperature heat source capable of digesting the latent heat of evaporation.

In other words, when the evaporator evaporates and there is no such supply of heat due to the latent heat of evaporation, the evaporator must absorb heat and evaporate from the surroundings. Therefore, the evaporator is deprived of heat simultaneously with evaporation, .

Also, since the condenser radiates heat due to the latent heat of condensation, the condensation is obstructed due to the high temperature, and the power generation efficiency is significantly lowered due to the high negative pressure.

1, the pressure difference between the evaporator and the condenser must be large in order to improve the efficiency, so that the pressure difference must be maximized. In addition, The refrigerant is expanded to a high temperature and a high pressure as a separate external heat source. Therefore, in order to facilitate the condensation, more cooling must be performed. Accordingly, a separate cooling device is required for the condenser.

More specifically, the condition of condensation is to raise the pressure when the temperature is constant, and when the pressure is constant, the temperature changes from gas to liquid only if the temperature is lowered. Conversely, if the temperature is constant, If you raise the temperature, evaporation will occur.

As shown in FIG. 1, in a conventional power generation cycle, a refrigerant condensed at a certain high temperature and pressure capable of being condensed needs to be evaporated at a high temperature and a high temperature, so that more energy is required. As the temperature rises, the pressure is increased and the property to be liquefied and the temperature are increased, so that the property of evaporation collides with, so that a higher temperature energy is required.

In addition, since the difference in pressure and temperature between the condensing stage and the evaporating stage is the acquired energy, if a sudden pressure drop occurs in the condensing stage, the temperature is lowered so that the condensation is condensed. Therefore, the consumption amount of energy required for cooling also increases. There is a limit to the development as technology.

Since the Rankine cycle directly heats at high temperature (1300 ℃ or more), the minimum heating temperature required for evaporation can be calculated only by the calorific value of the fuel and the calorific value of the power without any special consideration. However, as a technology of using renewable energy, the minimum heating temperature necessary for evaporation of a heat medium for power generation in a cycle of low temperature heat generation can be analyzed as follows.

The minimum heating temperature for evaporating the refrigerant is the heat required for evaporating 1 kg of refrigerant (based on R-134a) at a saturation temperature of 0 ° C to a saturation pressure of 2.9 kgf / cm 2 (95 kcal / kg for refrigerant saturation steam table) The minimum heating temperature that can satisfy the amount of heat is 95/1 * 0.5 (specific heat) * 0.9 (efficiency) = 211 ° C because Q = G * C * T and T = Q / G * C. / cm < 2 >, the minimum heating temperature to meet the required heat transfer amount (101.7 kcal / kg) is required to be 101.7 / 1 * 0.5 * 0.9 = 226 ° C .

That is, in the case of the low-temperature power generation using the refrigerant as the working fluid in the indirect heating heat exchange system, continuous evaporation can be performed only when the minimum heating temperature is 211 ° C or more.

Therefore, considering that the main temperature of low-temperature power generation utilizing low-temperature heat is less than 100 ° C, in the conventional technology of using renewable energy by indirect heating, evaporation of refrigerant due to temperature rise causes pressure It is virtually impossible and economically inefficient.

In a closed circulation cycle, evaporation takes place in the evaporator, which requires a heating temperature equal to the open heat of the evaporator to absorb the latent heat of vaporization. In the low-temperature power generation cycle, the refrigerant as a working fluid is automatically evaporated as soon as it is transferred to the evaporator.

However, if heat of 211 ° C or less, which is the minimum heating temperature necessary for evaporation, is supplied to the evaporator, the temperature is not increased due to the latent heat of evaporation of the refrigerant, the heat is removed by latent heat and the temperature of the evaporator itself falls, Serious conflicts will occur within.

As described above, in the conversion of heat into electric energy, the heat required for evaporation is closely related to the temperature, and evaporation is possible without securing the temperature above the temperature at which the latent heat of evaporation can be absorbed. However, Since the continuous evaporation can not be expected in the secured state, it is necessary to ensure the open heat based on the minimum heating temperature above the temperature at which the latent heat can be extinguished, so that it is possible to generate electricity through the turbine by increasing the pressure by continuous evaporation.

For the above reasons, the conventional power generation cycle requires a high temperature capable of digesting the latent heat of evaporation. However, since it is difficult to obtain the required temperature in terms of realistic and economical aspects, it is difficult to expect the power generation efficiency. Advancement as a technology of use becomes less economical value.

Meanwhile, in the conventional steam power generation cycle, the steam is directly generated from the steam boiler to generate steam, the turbine is operated with high-temperature and high-pressure steam, the steam is circulated through the condenser, and the water pump (steam) The power generation unit, and the condenser, but this consumes a great amount of heat due to the latent heat of evaporation when water is changed into steam in the steam generator.

In recent years, development of high temperature water power generation devices which generate heat at relatively high temperature, such as solar heat and factory waste heat, has been actively studied among the utilization technologies of new and renewable energy, but it has not been widely used so far and water can be evaporated A specific analysis of the heating temperature is required.

Among technologies that utilize renewable energy, technologies that convert heat into electrical energy include condensing solar power generation, steam generation cycles that produce electricity at relatively high temperatures, such as factory waste heat, and electricity generated from heat in everyday life. Low temperature water power generation cycle.

The use of condensing type solar heating technology has developed a technology that collects heat close to 1000 ° C and collects the heat to accumulate it. However, the technology that utilizes that heat, such as solar power generation and waste heat, Is still in the research stage.

The use of new and renewable energy technologies is not a direct heating method that generates electricity by the Rankine cycle but the organic Rankine cycle, the Kalina cycle, and the binary cycle, which indirectly heat the heat by collecting heat. All of these systems are systems that generate heat by exchanging heat through a heat exchanger to evaporate and obtain the required pressure.

In the technology of using renewable energy, the type of heat that can be exchanged with the heat exchanger is that the heat is collected through the heat exchanger through the heat exchanger, and the heat is collected by the air heat or some fluid.

If steam can be exchanged by heat, it will be able to evaporate by exchanging heat because it uses latent heat of steam, but it can not be heat-exchanged with steam in the technology of using renewable energy. This is because if there is steam, it can be developed without any reason for heat exchange. If you heat a few degrees of heat and see if it can evaporate, you can see below.

The minimum heating temperature required for the evaporation of 1 kg of water at a saturation temperature of 100 ° C at a saturation pressure of 1 kgf / cm 2 and continuous evaporation is 639 kcal / kg by the saturated steam table, Assuming that the heating temperature is T = 639/1 * 1 = 639 ° C and the efficiency of the heat exchanger is 90% in the indirect heating system, the minimum heating temperature required for continuous evaporation is 39 * 1.1 = 703 ° C.

That is, the minimum heating temperature at which water can continuously evaporate under the above-described conditions is 703 ° C. If the heating temperature is insufficient, evaporation continues due to lack of heat, but continuous evaporation as much as the heat required for power generation It is not done and pressure does not rise.

The heating temperature and the minimum temperature required for the evaporation at a saturation temperature of 180 ° C and a saturated vapor pressure of 10 kgf / cm 2 are 663 kcal / kg by the saturated steam table, and the heating temperature is 663 / 1 * 1 * 0.9 = 729 ° C. Therefore, the minimum heating temperature at the time of evaporation with saturated steam at 180 ° C is not less than 729 ° C so that continuous evaporation can be performed.

As described above, in the high temperature water power generation by evaporation of water in the generation of conversion into electric energy by heat as the utilization technology of renewable energy, continuous evaporation can be expected only when the indirect heating minimum temperature necessary for evaporation is 703 ° C or more. However, even if such heat is difficult to collect and store, there are actually many obstacles to using it. The use of high-temperature heat will be said to consume as much heat as possible, and it is expected that there will be a considerable difficulty in developing heat using heat storage in terms of economy and efficiency.

For the above-mentioned reasons, in the power generation cycle in which heat is converted into electric energy in the utilization technology of new and renewable energy, a high temperature capable of digesting the latent heat of evaporation is required in the existing conventional cycle. However, It is difficult to secure the temperature, and accordingly, the power generation efficiency is low. Therefore, a more efficient power generation cycle is required.

(0001) Korean Patent Publication No. 1236070 (Registered on Feb. 23, 2013) (0002) Korean Patent Publication No. 0766101 (Registered on October 4, 2007) (0003) Korean Patent Registration No. 1249188 (Registered on March 31, 2013) (0003) Korean Patent Publication No. 1188335 (registered on September 27, 2012)

It is an object of the present invention to provide a high-efficiency power generation cycle in which heat loss due to the latent heat of evaporation is reduced (or minimized) in the course of a phase change from liquid to gas.

In addition, the various fluids that evaporate at low temperature are generated by heat medium and are able to generate heat at a temperature of 40 ° C or more over all stages of compression, heat exchange, expansion, condensation, expansion and evaporation. And to provide a high-efficiency power generation cycle that can be developed using low-temperature heat sources such as power generation and the like.

The above object is achieved according to the present invention by providing a turbine and a generator which are circulated in six stages of compression, heat exchange, expansion (power generation), condensation, expansion and evaporation as a cycle of generating electricity by driving a turbine with a refrigerant or water as a heat medium, A power generator including; A condenser for absorbing and condensing the heat of the heating medium; An evaporator for supplying heat to the heat medium to evaporate; A compressor for compressing and transferring the heating medium; And a heat exchanger for heating the heating medium to a high temperature and high pressure gas by an external heat source to drive the turbine, wherein the heating medium is heated by a second heating and cooling circulation line in the evaporator so as to reduce energy loss due to latent heat of evaporation And is heated by the heat exchanger after being evaporated after being supplied with heat required for evaporation.

And a heat storage tank for storing the external heat source of solar heat, waste heat, geothermal heat or air heat, and a first circulation line for exchanging heat by circulating the first fluid through the heat storage tank and the heat exchanger may be formed.

The first circulation line extends to the evaporator, and the first fluid circulates through the heat storage tank, the heat exchanger and the evaporator to exchange heat.

A second heating and cooling circulation line may be formed in which the second fluid circulates through the condenser and the evaporator to exchange heat so that heat of the heating medium absorbed in the condenser is supplied to the heating medium in the evaporator.

A water heater is provided between the condenser and the evaporator to supply heat to the heat medium to facilitate evaporation of the heat medium in the evaporator, and the second circulation line circulates the condenser, the water heater and the evaporator to exchange heat .

The first circulation line and the second circulation line may be connected in parallel to each other at a set temperature by a three-way valve.

An expansion valve may be provided between the condenser and the evaporator to depressurize the heating medium by a wire drawing effect.

A sub tank for storing and supplying the heat medium may be installed between the condenser and the evaporator so that the heat medium is uniformly supplied to the evaporator.

An auxiliary condenser may be installed between the power generator and the condenser so that the cooling efficiency of the second circulation line is improved and the heating medium is easily evaporated at low temperature and low pressure.

A pressure control valve may be provided between the heat exchanger and the power generator to open at a pressure higher than a set pressure so that the heating medium having a high temperature and a high pressure is sprayed at a constant pressure from the turbine.

Between the condenser and the evaporator, a circulation pump for pressurizing the heating medium may be installed.

And a water recovery pipe connecting the heat exchanger and the compressor may be formed so that the heating medium liquefied in the heat exchanger is recovered to the compressor.

A bypass pipe for collecting the heat medium compressed by the compressor is formed on the front and rear sides of the compressor, and a pressure accumulating tank through which the over-compressed heat medium is recovered through the bypass pipe is installed between the compressor and the evaporator .

According to the present invention, there is provided a power generator comprising: a power generator including a turbine and a generator; A condenser for absorbing and condensing the heat of the heating medium; An evaporator for supplying heat to the heat medium to evaporate; A compressor for compressing and transporting the heating medium; And a heat exchanger for heating the heating medium to a high temperature and high pressure gas by an external heat source to drive the turbine, wherein the heating medium is reduced in (or minimized) heat loss due to the latent heat of evaporation as it is evaporated in the evaporator and then heated in the heat exchanger It is possible to provide a highly efficient power generation cycle.

Also, the various fluids that evaporate at low temperatures are generated by heat medium and are able to generate heat at temperatures over 40 ° C over all stages of compression, heat exchange, expansion, condensation, expansion and evaporation. It is possible to provide a high-efficiency power generation cycle that can be generated using power generation and other low-temperature heat sources.

1 shows a conventional power generation cycle.
Figures 2 to 4 show a high efficiency power generation cycle according to an embodiment of the present invention.
Figures 5 and 6 are diagrams illustrating the performance and performance of the high efficiency power generation cycle of Figure 2;
7 to 9 are diagrams showing a high-efficiency power generation cycle according to another embodiment of the present invention.
Figs. 10 and 11 are diagrams showing the performance and the performance of the high-efficiency power generation cycle of Fig. 7 with water as a heating medium; Fig.
12 is a view showing a combined power generation system of high efficiency power generation cycle utilizing high temperature and low temperature heat.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, the well-known functions or constructions are not described in order to simplify the gist of the present invention.

The high-efficiency power generation cycle of the present invention is a cycle in which the heat loss due to the latent heat of vaporization is reduced (or minimized) during the phase change from liquid to gas, and various fluids that evaporate at low temperature are generated as heat medium, and are compressed, heat exchanged, expanded, , And can be generated at a temperature of 40 ° C or more over the entire stage of evaporation and can be generated using solar heat, factory waste heat, ground water heat, geothermal heat, seawater temperature difference power generation, and other low temperature heat sources.

FIGS. 2 to 4 are diagrams showing a high efficiency power generation cycle according to an embodiment of the present invention, FIGS. 5 and 6 are diagrams showing the performance and performance of the high efficiency power generation cycle of FIG. 2, and FIGS. Fig. 10 is a view showing a high efficiency power generation cycle according to another embodiment. Fig. 10 and Fig. 11 are diagrams showing the performance and performance of the high efficiency power generation cycle of Fig. 7 using water as a heat medium. A second low temperature power generation system using heat.

As shown in FIG. 2, the high-efficiency power generation cycle 1 according to the embodiment of the present invention allows the refrigerant gas having a low boiling point to be evaporated at a low temperature and a low pressure with a heating medium for power generation, A heat exchanger 40, a pressure regulating valve V1, and a power generator 30, which are configured to convert thermal energy to electric energy by using a high-pressure heating medium gas for power generation. The condenser 10, the evaporator 20, the compressor 30, (50). In one embodiment of the present invention, the refrigerant gas comprises R-134a.

As shown in FIG. 2, the evaporator 20 is configured to supply heat to the heat medium to evaporate. The heat medium for power generation, which is liquefied at a low temperature and a low pressure, is cooled by the cooling cycle of the second circulation line L2 in the evaporator 20 Isothermal evaporation takes place while the state is changed to gas gas of low temperature and low pressure by natural vacuum.

The second circulation line (L2) conveys heat and is cooled to extinguish latent heat of evaporation. Therefore, the evaporation latent heat is absorbed and evaporated without supplying the external heat source, thereby reducing the energy consumption.

The compressor (30) serves to transfer the heating medium to the heat exchanger (40) so that the heating medium can be continuously evaporated in the evaporator (20). Evaporation can occur without the use of the expansion valve V2 between the condenser 10 and the evaporator 20. Fig. 4 shows a power generation cycle in which the expansion valve V2 is omitted between the condenser 10 and the evaporator 20. Fig.

2, in the heat exchanger 40, the low-temperature, low-pressure heat medium gas transferred from the compressor 30 is heated by heat from solar heat, waste heat and other heat sources, and is heated And is thermally expanded by a high-temperature and high-pressure gas.

The pressure regulating valve (V1) supplies the heating medium expanded at a high temperature and a high pressure to the power generator (50) at a constant pressure, and the refrigerant turbine is driven to perform a monotonic expansion in which the generator is activated.

In the condenser 10, the expanded high-temperature and low-pressure heat medium gas is condensed at a low temperature and a low pressure while being discharged by static pressure by the second purifying line, and the condensate can be generated when the condensate water recovery pipe L3 is heated and compressed by the heat exchanger 40 And is returned to the compressor (30).

3 and 4, a bypass pipe L4 may be installed in the high-efficiency power generation cycle of the present invention. The bypass pipe L4 serves to regulate the compression performance of the compressor 30 to transfer a predetermined amount of the heat medium, and the overheated heat medium is recovered to the accumulation tank T2. The pressure accumulating tank (T2) regulates the pressure of the heating medium to be evaporated so as to ensure the performance of the compressor (30) and assures the performance of the compressor (30).

In addition, the sub-tank T1 may be installed in the high-efficiency power generation cycle of the present invention. The sub tank T1 serves to secure a condensed heat medium so that the condensed heat medium can be evaporated in the evaporator 20 in a constant manner and to supply the condensed heat medium, , And a device capable of recovering the heat medium at the time of replacement and repair.

The auxiliary condenser 80 may be installed in the high-efficiency power generation cycle of the present invention. The auxiliary condenser (80) for first cooling the heat medium expanded by the heat of the heat obtained from the heat exchanger (40) separately from the condenser (10) is installed separately by dry and wet operation and improves the efficiency of the second cooling cycle And the heat medium facilitates low temperature evaporation.

2, the second heating and cooling circulation line L2 circulating the condenser 10 and the evaporator 20 is circulated by the circulation pump P and crosses the temperature change without changing the state, In the evaporator 20, heat is absorbed as much as the latent heat of condensation, and the evaporator 20 functions as a circulation cycle for facilitating the evaporation of the heat by the cooling water heated by the latent heat of evaporation. It serves to extinguish condensation heat.

2 and 3, the expansion valve V2 is provided between the condenser 10 and the evaporator 20 as a structure that facilitates evaporation in the evaporator 20. [ As shown in FIG. 4, the high-efficiency power generation cycle 1 according to the present invention can naturally expand and conceal expansion without providing an expansion valve, resulting in thermal expansion and contraction expansion.

Referring to FIG. 3, the makeup water tank T3 is installed in the water supply pipe to store the makeup water. A heat storage tank 60 for storing external heat, a first circulation line L1 for supplying the heat accumulated in the heat exchanger 40, and a circulation pump P are shown.

The performance of the high-efficiency power generation cycle 1 according to an embodiment of the present invention is analyzed as follows.

The efficiency of the high-efficiency power generation cycle (1) is 70%, the efficiency of the heat exchanger (40) is 85%, the specific heat of R-134a refrigerant is 0.5 kcal / kg ° C, The latent heat is set at 42.32 kcal / kg, and since it is naturally evaporated as it is transferred to the evaporator 20 due to the characteristics of the refrigerant, the sensible heat is ignored and only the specific heat and latent heat are calculated.

The required calorific value is 143 kcal / hr (143 kcal / hr) and 143 kcal / hr (143 kcal / hr). The amount of heat Q necessary for evaporating 1 kg of refrigerant is 1 * 0.5 + 0 / 0.85 = 0.5 = 1 kcal / kg, the capacity of the evaporator 20 is 3,386 * 1 / 0.85 = 3,990 kcal / hr, 3 < 0 > C, T = 3,990 / 3,386 * 0.5 = 2.36.

Therefore, the cycle of the present invention is spontaneously evaporated at a temperature of 0 ° C or lower, and the heating temperature immediately leads to power generation.

Based on this standard performance, the amount of power that can be generated by substituting external heat source as follows is calculated as follows.

The capacity of the evaporator 20 is 3,990 kcal / hr. When the refrigerant 3,386 kg is evaporated to 200 ° C, the heat capacity is Q = 3,386 * 200 * 0.5 = 338,600 kcal / hr. It is possible to generate heat of 338,600-3,990 = 334,610 kcal / hr = 334,610 / 860 * 0.7 (cycle efficiency) = 272 kw because the power can be generated by the amount of heat excluding the capacity of the evaporator 20 because it is higher than the desired temperature.

The evaporator 20 capacity at the time of external heat heating at 80 ° C is as follows.

When 3,386 kg of refrigerant is heated to 80 ℃, the heat capacity Q = 3,386 * 80 * 0.5 = 135,440 kcal / hr and the power generation capacity is 135,440-3,990 = 131,450 / 860 * 0.7 = 106 kw.

When the evaporator 20 is heated to 40 ° C, the capacity of the evaporator 20 is calculated as follows.

When 3,386 kg of refrigerant is heated to 40 ℃, the heat capacity is Q = 3,386 * 40 * 0.5 = 67,720 kcak / hr and the power generation capacity is 67,720-3,990 = 63,730 / 860 * 0.7 = 51 KW.

Therefore, in the high-efficiency power generation cycle 1 according to the embodiment of the present invention, the desired amount of power can be generated by increasing the capacity of the evaporator 20 when the temperature is 40 ° C or higher, The capacity of the evaporator 20 can be increased or decreased.

In conclusion, the conventional power generation cycle as a technology for using renewable energy has been proved as a performance analysis because the power generation is uneconomical and inefficient and the efficiency is low. In particular, since the development in the renewable energy field using low temperature heat is an indirect heating method, the evaporation does not occur smoothly below the desired temperature in the performance data.

This is because the working fluid is conveyed to the evaporator 20 through the compressor 30, and if it is not higher than the temperature at which the latent heat can be extinguished, even if the evaporator attempts to evaporate, the heat is insufficient and the pressure is increased by the compressor 30, Serious conflicts will occur.

On the other hand, the high-efficiency power generation cycle 1 according to an embodiment of the present invention can generate power at a temperature that can satisfy the planned generation capacity when the temperature is 40 ° C or higher.

5 is a P-h diagram of the high-efficiency power generation cycle 1 of the present invention, showing the relationship between pressure and enthalpy. When the pressure is high, the temperature is high. When the pressure is low, the temperature is low. Increasing the temperature also increases the pressure and volume and increases the enthalpy.

'A' represents the loss energy of the compressor 30 as a change in a state where the compressor 30 does not exchange heat with the outside as a compression change section.

'B' is a section in which the temperature and the pressure are converted by the compression due to the transport of the heating medium by the compressor 30 and the heating due to the supply of the external heat source. The pressure and the temperature increase together with the increase of the enthalpy, Indicating a relative increase in proportion to temperature.

'Represents the amount of energy obtained as a portion in which an external heat source equal to or higher than the temperature required for the set pressure is supplied in advance before the pressure and temperature rise by the compressor (30).

'D' indicates that the amount of energy to be obtained increases with an increase in the temperature when the external heat source is supplied at a reference temperature of 40 ° C or more.

'D' indicates that the refrigerant in the high-pressure gas state is a section where the turbine is operated and the low-pressure gas refrigerant is changed, consuming the enthalpy obtained from the external heat source, and generating a thermal expansion.

'ㅁ' indicates a section in which the low-pressure gas refrigerant undergoes a constant pressure heat release and is phase-changed and condensed from the gas state to the liquid state.

'P' is the interval of the adiabatic change, which is the section where the low-temperature and low-pressure liquid expands and the pressure is lowered.

'G' indicates a process in which a low-temperature low-pressure liquid refrigerant is phase-changed into a low-pressure low-temperature gaseous refrigerant and is isothermal evaporated.

'A' shows the amount of energy in the heat source of 40 ° C which is the minimum temperature suggested by the present invention. &Quot; I " indicates the amount of energy and the pressure of the external heat source at 50 DEG C according to the present invention. 'Da' indicates the amount of pressure and energy at an external heat source temperature of 60 ° C according to the present invention. 'R' represents the critical point, 'E' represents the saturated liquid line, and 'Bar' represents the saturated steam line. 'SAR' represents the wet steam region where the gas state and the liquid state are mixed.

FIG. 6 is a graph showing the performance of the present invention according to the enthalpy. The 'A' zone shows the magnitude of pure acquisition energy according to the change of enthalpy, and the zone of 'B' The 'C' zone represents the consumed energy of the compressor 30, and the 'D' zone represents the amount of energy acquired during the external heat exchange at a minimum temperature of 40 ° C. or higher.

As shown in FIG. 6, the amount of energy consumed in the 'B' zone is obtained so that the amount of change in enthalpy is constant and the energy excluding the consumed energy 'C' from the acquired energy 'A' . The 'D' portion shows that the amount of the acquired energy increases in direct proportion as the temperature of the external heat source heated in the heat exchanger 40 increases. Therefore, if the temperature of the external heat source is high, the amount of energy to be obtained increases, so that the high efficiency can be developed.

Also, when the temperature of the refrigerant as the heating medium increases, the pressure rises, and when the temperature decreases, the pressure also falls, indicating that the high-efficiency power generation cycle 1 of the present invention is directly related to the temperature.

On the other hand, if the difference between the condensation temperature and the evaporation temperature is decreased, the amount of energy lost is decreased. If the evaporation temperature is lowered, the amount of energy to be obtained increases and the temperature of the external heat source Can be confirmed.

As shown in FIG. 7, the high-efficiency power generation cycle 2 according to another embodiment of the present invention reduces (or minimizes) the energy consumption due to the latent heat of vaporization in the course of a phase change from liquid to gas as a steam power generation cycle And includes a water heater 70, an evaporator 20, a compressor 30, a heat exchanger 40, a pressure regulating valve V1, a power generator 50, a condenser 10, a circulation pump P, (60).

The water heater 70 is a series of hot water storage facilities in which the temperature of the working fluid reduced water conveyed by the circulation pump P in the condenser 10 is heated to enable low temperature evaporation at a set temperature.

The evaporator 20 is supplied with the heat corresponding to the latent heat of evaporation by the second circulation line L2 and evaporates at low temperature while circulating the latent heat to the condenser 10. The evaporator 20 evaporates water at 80 ° C at a vacuum pressure of about 355 mmHg and the circulating water of the second circulation line L2 must be higher than the low temperature evaporation temperature of 80 ° C to absorb the latent heat of evaporation of the heating medium, And the circulating water cooled to about 80 ° C is circulated to the condenser 10.

In the method of maintaining the vacuum in the evaporator 20, the heating medium having a temperature higher than the low temperature evaporation temperature is cooled to the low temperature evaporation temperature, the vacuum is maintained by the decrease of the volume, and the heating medium is continuously heated by the compressor 30 Is transferred to the evaporator (40) so that continuous low temperature evaporation is maintained.

The compressor (30) conveys the steam evaporated at low temperature below 100 degrees to the heat exchanger (40).

In the heat exchanger (40), the low-temperature low-pressure humidified vapor is heated to an external heat source of 286 DEG C or higher and pressure expanded by the high-temperature high-pressure dry saturated vapor.

In the pressure regulating valve V1, the high-temperature high-pressure steam is delivered to the turbine of the power generator 50 at a constant pressure.

The power generator 50 is an engine part in which high-temperature, high-pressure steam is regulated to a constant pressure in the pressure regulating valve V1 to operate the steam turbine and generate electricity to the generator.

The condenser 10 is an open type condenser for storing the circulating water of the working fluid which condenses and liquefies the high-temperature wet steam passing through the turbine, the deficient water is replenished to be discharged to the external heat source or the heat is absorbed in the second circulation line L2 Device.

The circulation pump P is a device for transferring the condensed water from the condenser 10 to the water heater 70, and may be omitted in case of vacuum evaporation as shown in FIG.

7, the heat storage tank 60 is a tank that collects heat by collecting solar heat or waste heat, and is connected to a heat collecting unit (not shown) having a heat source as a circulating line of an external heat source, L1 to the heat exchanger 40 and the evaporator 20 to supply hot water.

9, the heat storage tank 60 may be connected to the heat exchanger 40, the evaporator 20, and the condenser 10 through a first circulation line L1 to supply hot water. A circulation pump P is installed in the first circulation line L1.

7, the second circulation line L2 absorbs heat in the condenser 10, and the circulating water heated is circulated by the circulation pump P to the evaporator 20, and the evaporation temperature Water that is a working fluid absorbs heat from the second circulation line L2 and can be evaporated at a low temperature by exchanging heat with the evaporator 20 at a temperature of about 95 deg. C higher than 80 deg.

In addition, the second circulation line L2 dissipates heat in the evaporator 20 to facilitate evaporation, so that the second circulation line L2 cools to a low temperature evaporation temperature at 95 DEG C and absorbs the latent heat. The circulating water cooled to about 80 캜 absorbs heat in the condenser 10 and absorbs heat at 95 캜 to form a circulation cycle. In addition, the second circulation line L2 maintains the temperature of the water heater 70 at an arbitrarily set temperature of about 95 캜 so as to be kept higher than the low temperature evaporation temperature.

Between the power generator (50) and the condenser (10), a bypass pipe can be installed to directly absorb heat at a high temperature, and a water replenishment pipe for supplementing water can be further provided.

8, the second circulation line L2, the water heater 70, and the circulation pump P may be omitted, and a separate dry or wet cooling device may be connected to the condenser 10.

The performance of the conventional cycle and the high-efficiency power generation cycle 1 of the present invention is analyzed as follows.

The efficiency of the evaporator 20 (heat exchanger 40) is 85%, the temperature of the condensed water reduced from the condenser 10 is 80 ° C (operation The fluid is assumed to be water), and only saturated steam evaporating at 100 ° C vapor is assumed to be calculated.

First, when calculating the performance of the conventional cycle (Rankine, Brayton, Calina cycle, etc.), the required converted calorie is Q = 200 * 860 / 0.3 = 573,000 kcal / hr when 1 kw is applied at 860 kcal, Q = {1 * (100-80) * 1 + 539 * 1} /0.85= (1) The amount of heat required to evaporate 1 kg of water is 573,000 / 539 = 1,063 kg / The capacity of the evaporator 20 (heat exchanger 40) is Q = 1,063 * 658 = 699,000 kcal / hr since it is evaporation amount * heat required for evaporation. Therefore, the economical desired minimum temperature that can satisfy the capacity of the heat exchanger 40 and the evaporation amount is 699,000 / 1,063 * 1 = 658 ° C at T = Q / G * C.

On the other hand, when the heat exchanger 40 is evaporated at 820 占 폚, the heat capacity of the heat exchanger 40 is Q = 1,063 * 820 = 871,660 kcal / hr when 1,063 kg of water is exchanged at 820 占 폚. 40)) capacity is 699,000 kcal / hr, so it is 871,660 - 699,000 = 172,660 kcal / hr and it is possible to develop 172,660 / 860 = 200 kw.

That is, evaporation starts at 658 ° C, which is the desired minimum temperature of the design standard performance, but minimum heating temperature for continuous evaporation required for power generation is at least 820 ° C.

As a result, unless the temperature is above the desired temperature, it is difficult to digest the latent heat and the evaporation continues but the designed evaporation amount for the power generation can not be met, so continuous evaporation is impossible and the additional heat must be heated above the desired temperature required for evaporation, .

Meanwhile, the performance of the high-efficiency power generation cycle (2) of the present invention can be calculated as follows.

Q = 1,063 * 545 = 579,335 kcal / hr (latent heat of evaporation at 90 ° C) / 0.85 = 681,570 kcal / hr since the required calorific value is the evaporation amount of 1,063 kg / hr in the Rankine cycle. This value is the amount of heat generated by the latent heat in the evaporator 20, which is the amount of heat to be met by a cooling circulation cycle in which low temperature heat is exchanged by ambient temperature or heat storage to supply only heat regardless of temperature. It is necessary to calculate the calorific value without needing to discuss it, so it can be omitted from the design calorific value.

The heat amount in the water heater 70 is Q = 1,063 * (95-60) * 1 / 0.85 = 43,770 kcal / hr (calculated by vacuum evaporation at 95 ° C and reduction temperature of the condenser 10 at 60 ° C) ), The amount of heat required to raise 1 kg of saturated steam by 1 ° C is Q = 1 * 0.5 * 1 = 0.5 kcal / kg, and the amount of heat required to raise the evaporation amount of 1,063 kg by 1 ° C is 1,063 * 0.5 / 0.86 = 626 kcal / hr. The desired temperature required for evaporation is the boiling temperature, which is higher than the boiling evaporation temperature of 95 ° C.

Calculation of the capacity of the heat exchanger 40 during heat exchange at 500 ° C results in a calorific value of 1,063 * 0.5 / 0.85 = 626 kcal / hr in the heat exchanger 40 and a calorific value Q = 1,063 (365,93-626 = 365,311 kcal / hr) can be used as the enthalpy of superheated steam and can be used as the calorific value of power generation. The capacity can be increased to 365,311 / 860 = 425 kw.

Therefore, the desired temperature of 200 kilowatts at an evaporation amount of 1,063 kg is t = (200 * 860) /0.85+532=202,885/1,063 = 190.9 = 191 ° C. Therefore, when the evaporation temperature of 95 ° C is added, 286 ° C is calculated as the desired power generation temperature.

On the other hand, when calculating the capacity of the heat exchanger 40 during the heat exchange at 286 ° C, the heating amount of 1,063 kg of saturated steam at 286 ° C is 1,063 * (286-95) = 203,033 kcal / hr, It is possible to use 202,501 kcal / hr as the enthalpy of superheated steam, and the power generation capacity can be generated as 202,501 / 860 * 0.85 = 200 kw.

That is, it is possible to evaporate at a desired temperature of 95 ° C or higher, and the desired minimum heating temperature for economic development is 286 ° C. However, in the conventional method, it is evident that the desired minimum heating temperature is achieved only when the desired temperature is evaporated at 658 ° C and is higher than 820 ° C

The standard capacity of the conventional heat exchanger 40 is 699,000 kcal / hr at 820 DEG C or higher and the standard capacity of the heat exchanger 40 (evaporator 20) in the high efficiency power generation cycle 1 of the present invention is 90 DEG C 0.85 = 43,770 kcal / hr, and the heat amount of the heat exchanger 40 is 532 / 0.85 = 626 kcal / hr. As a result, The total calories were 725,966 kcal / hr, and the heat of 725,966 - 699,000 = 26,966 kcal / hr was more than the Rankine cycle due to the increase of latent heat by low temperature evaporation. However, the heat of the evaporator (20) Because it is possible to substitute with calories, the difference between the total calorific value and the possible temperature difference is not compared. As the utilization technology of new and renewable energy, it is difficult to collect or store heat at high temperature, and therefore, the efficiency of the conventional method is inevitably low.

As shown in FIGS. 5 and 10, the high-efficiency power generation cycle according to another embodiment of the present invention includes three constant-pressure processes, two thermal expansion processes, and two booster processes.

The three positive pressure processes are as follows. (1) In FIG. 5, the circulation pump P performs the adiabatic constant pressure process on the same line as the process of changing the wet steam into the saturated water by the static pressure heat radiation in the condenser 10 in the section e in FIG. The condensation process on the same line in which the constant pressure endothermic process is formed by the hot water heater 70 and the process of the constant pressure endothermic evaporation in which the low pressure vacuum evaporation is performed in the evaporator 20 in the g section in FIG. (C) in FIG. 5, and the heat exchanger (40) in the section (c) in FIG. 10, the compressor (30) is converted into the isothermal constant pressure conversion section by a high temperature external heat source, There is a process in which the superheated temperature is supplied in advance before the ideal gas rises in pressure and temperature.

Accordingly, when a temperature higher than the set pressure is necessarily supplied, the pressure does not collide with the property to be condensed and the step of the constant pressure heating in which the dry saturated steam and the superheated steam are formed is carried out. According to the Boyle- As the temperature rises, the pressure and the volume increase and the enthalpy increases. When the volume is constant, the pressure increases proportionally as the temperature increases. Thus, energy is stored by increasing the amount of heat due to the pressure increase. The performance is shown.

5, in the sections d, f in FIG. 5, as shown in the sections d and f, the process of performing the mechanical work while performing the adiabatic expansion in the turbine by the two adiabatic expansion processes and the process of performing the adiabatic expansion by the vacuum it means.

As shown in FIG. 5, the two boosting processes are as shown in FIGS. 5A and 5B and FIG. 10A and FIG. 10B as a section where the compressor 30 undergoes heat compression and compression, The pressure and temperature of the evaporator 20 and the heat exchanger 40 increase and the pressure and the temperature rise together with the external heat source. The booster process takes place.

As shown in FIG. 11, 'A' indicates that the amount of energy consumed by the compressor 30 is equal to the amount of energy lost, 'B' indicates the magnitude of the pure acquired energy, 'C' The amount of pure energy acquired is represented by 'B-C'. The higher the temperature of the heat exchanger (heating), the higher the pressure is increased to increase the amount of energy acquired. Able to know.

According to the present invention, a power generator (50) comprising a turbine and a generator, which generates electricity by driving a turbine using a refrigerant or water as a heating medium; A condenser (10) for absorbing and condensing the heat of the heating medium; An evaporator (20) for supplying heat to the heat medium to evaporate; A compressor (30) for compressing and transferring the heating medium; And a heat exchanger (40) for heating the heating medium to a high temperature and high pressure gas by an external heat source to drive the turbine. The heating medium is evaporated in the evaporator (20) and heated in the heat exchanger (40) It is possible to provide a high-efficiency power generation cycle 1 in which the heat loss caused by the heat generated by the power generation is reduced (or minimized).

Also, the various fluids that evaporate at low temperatures are generated by heat medium and are able to generate heat at temperatures over 40 ° C over all stages of compression, heat exchange, expansion, condensation, expansion and evaporation. It is possible to provide a high-efficiency power generation cycle (1) capable of generating electricity using power generation and other low-temperature heat sources.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is obvious to those who have. Accordingly, it should be understood that such modifications or alterations should not be understood individually from the technical spirit and viewpoint of the present invention, and that modified embodiments fall within the scope of the claims of the present invention.

1: High-efficiency power generation cycle 10: Condenser
20: evaporator 30: compressor
40: heat exchanger 50: power generator
60: heat storage tank 70: water heater
80: auxiliary condenser P: circulation pump
L1: first circulation line T1: sub tank
L2: second circulation line T2: accumulator tank
L3: Nodule recovery pipe T3: Replenishment water tank
L4: Bypass tube
V1: Pressure regulating valve
V2: expansion valve

Claims (13)

A cycle in which a turbine is driven by a refrigerant or water as a heat medium and is circulated in six stages of compression, heat exchange, expansion (power generation), condensation, expansion and evaporation,
A power generator including the turbine and a generator;
A condenser for absorbing and condensing the heat of the heating medium;
An evaporator for supplying heat to the heat medium to evaporate;
A compressor for compressing and transferring the heating medium; And
And a heat exchanger for heating the heating medium to a high temperature and high pressure gas by an external heat source to drive the turbine,
Wherein the heating medium is evaporated in the evaporator and then heated in the heat exchanger so that energy loss due to the latent heat of evaporation is reduced. The method according to claim 1,
And a heat storage tank for storing the external heat source of solar heat, waste heat, geothermal heat or air heat,
And a first circulation line through which heat is exchanged between the heat storage tank and the heat exchanger by circulating the first fluid. 3. The method of claim 2,
Said first circulation line extending into said evaporator,
Wherein the first fluid circulates through the heat storage tank, the heat exchanger and the evaporator to exchange heat. 3. The method of claim 2,
And a second heating and cooling circulation line is formed in which the second fluid circulates through the condenser and the evaporator to exchange heat so that heat of the heating medium absorbed by the condenser is supplied to the heating medium in the evaporator. cycle. 5. The method of claim 4,
A water heater is provided between the condenser and the evaporator to supply heat to the heat medium to facilitate evaporation of the heat medium at a low temperature in the evaporator,
And the second circulation line circulates the condenser, the water heater and the evaporator to exchange heat. 5. The method of claim 4,
Wherein the first circulation line and the second circulation line are connected in parallel to each other and controlled to a set temperature by a three-way valve. 3. The method of claim 2,
Wherein an expansion valve is provided between the condenser and the evaporator to reduce the heating medium by a wire drawing effect, and when the vacuum low-pressure evaporation is omitted, throttling expansion occurs even if the expansion valve is omitted. 3. The method of claim 2,
Wherein a sub tank for storing and supplying the heat medium is installed between the condenser and the evaporator so that the heat medium is uniformly supplied to the evaporator. 5. The method of claim 4,
Characterized in that an auxiliary condenser is installed between the power generator and the condenser to improve the cooling efficiency of the second circulation line. The method according to claim 1,
Wherein a pressure regulating valve is provided between the heat exchanger and the power generator so as to open at a pressure higher than a set pressure so that the heat medium having a high temperature and a high pressure is sprayed at a constant pressure from the turbine. The method according to claim 1,
And a circulation pump for pressurizing the heating medium is installed between the condenser and the evaporator. The method according to claim 1,
And a water recovery pipe connecting the heat exchanger and the compressor is formed so that the heat medium liquefied in the heat exchanger is recovered to the compressor. The method according to claim 1,
A bypass pipe for collecting the heat medium compressed by the compressor is formed on the front and rear sides of the compressor,
And a compression tank in which the heat medium compressed and compressed through the bypass pipe is recovered is installed between the compressor and the evaporator.

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