JPS58185911A - Motive power generator - Google Patents

Abstract

PURPOSE:To collect heat always at the maximum energy efficiency in a plant which generates power by use of sun heat or waste heat of a plant by integrating a plurality of heat accumulation tanks which differs in temperature of accumulated heat, in a heat collection loop and by selecting an appropriate one from those tanks according to condition of a heat source or so. CONSTITUTION:A heat collection loop is made up of a heat collector 1, three-way valves 11a and 11b, a steam generator 5, a heat accumulation tank unit 3, a heat medium circulation pump 4 and a bypass flow passage 40 which are properly connected to each other. The heat accumulation tank unit 3 consists of low and high temperature heat accumulation tanks 3a and 3b which differ in temperature of accumulated heat. A Rankine cycle 2 is formed by piping the steam generator 5, an expansion mechanism 6, a condenser 7 and a pump 8a. An optimum value of a temperature of heat medium at the inlet of the heat collector, determined according to temperature of open air and intense of solar radiation is shown by T0 and temperatures of heat accumulation tanks 3a and 3b are shown by T1 and T2. The three-way valves 12a and 12b are placed under change-over control as to select the low temperature heat accumulation tank 3a for T2>T0>T1 and select the high temperature heat accumulation tank 3b for T0>T2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power generation device that fully utilizes solar heat, factory waste heat, etc. to generate power.

Conventional power generation equipment that makes full use of solar heat and factory waste heat,
A heat collection loop that includes a heat source, a heat storage tank, and a heat medium circulation pump, and the amount of heat generated by the heat collection loop? It consists of a Rankine cycle that has a mechanism to convert it into power, but it depends on the thermal state of the heat source (insolation when using solar heat, heat source temperature when using all waste heat) and the thermal state of the outside world (air temperature or Rankine cycle). Since the heat medium circulation rate of the heat collection loop was set regardless of the vertical assembly temperature of the cycle) and the heat medium temperature on the heat source inlet side,
There was a drawback in that it was not possible to immediately achieve all optimal operating conditions in response to an increase in the amount of heat input at the heat source. This will be explained using FIGS. 1 to 3, which are exergy efficiency diagrams when gold and solar heat are used as heat sources. Here, exergi! ft defined by the formula (1) A, 6° where Q: total amount of heat supplied from the high temperature heat source TA: sieve heat source temperature TB: low temperature heat source temperature j['c: high temperature heat source absolute temperature, exergy efficiency is the ratio of exergy collected by the heat collector to the exergy contained in the heat collecting surface solar radiation aperture.

In Figures 1 to 3, the vertical axis is the heat medium temperature at the inlet of the solar collector, the horizontal axis is the heat medium circulation amount, the numerical values in the figures are exergy efficiency, and the solid lines are exergy efficiency contours at a certain amount of solar radiation and temperature. Breaking fi! represents the combination of the heat medium temperature at the collector inlet side and the heat medium circulation amount that maximizes the total exergy efficiency.

As shown in Figure 1, when the operating conditions are at point A, that is, the optimal operating conditions [the solar radiation increases from a certain solar radiation II state to 1 + Δ■ by 7 Jl], assuming that the temperature is constant, the optimal operating conditions are at point A. As shown in FIG. 2, when the temperature shifts to the high temperature side, and conversely, when the amount of solar radiation decreases to -Δ■, the optimum operating condition shifts to the low temperature side, as shown in FIG. As shown in Figure 2, when the amount of solar radiation increases, the heating mass in the collector increases, and after some time delay the operating conditions reach the optimum point B [but the heat medium layer at the collector inlet reaches point B]. It is necessary to operate in a state with low exergy efficiency until the level of pressure is reached.

Conversely, when the amount of solar radiation decreases as shown in FIG. 3, the temperature level of the heat collection loop of the power generator is too high, resulting in a decrease in -C exergy efficiency.

Such a shortcoming is also seen by colleagues when the heat source is other than large Is heat, for example when waste heat total heat ωλ is used. In this case, the same situation holds true when the heat source temperature is substituted for the amount of solar radiation in FIGS. 1 to 3.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an entire power generation device that can eliminate the above-mentioned drawbacks and can collect heat at the maximum exergy rate against fluctuations in the heat source and the external environment.

Vision 1 of the present invention: A detector that provides a plurality of heat storage tanks with different heat storage temperatures in the heat collection loop, and detects the heat source, the thermal state of the outside world, and the temperature of the heat storage tank, respectively. The present invention is characterized in that the heat storage tank used for heat collection is selected according to the detection result, and the amount of heat medium circulated in the heat collection loop is controlled.

The present invention will be explained below with reference to embodiments shown in the drawings.

FIG. 4 shows an embodiment in which the present invention is applied when the total heat source is solar heat. The heat collection loop includes a heat collector 1, a steam generator 5 connected to the heat collector 1 via a three-way valve 11ai, a heat storage 3 connected to the heat medium outlet side of the steam generator 5, and a heat medium A circulation pump 4, a bypass channel 40 for moistening and bypassing the heat medium discharged from the pump 4 into the heat collector 1, and a bypass flow channel 40 and an inlet flow channel for the heat medium to the heat collector 1. It consists of a three-way valve 11b provided at the connection part. The heat storage sliding part 3
are two heat storage tanks 3a having different heat storage temperatures.

3b (3ai high-temperature heat storage tank, 3b all low-temperature heat storage tank), and the three-way valve 12 determines whether the heat medium is completely passed through which of them.
It can be selected by switching a and 12b.

10,000, Rankino cycle 2, steam generator 5, expansion F!
It consists of a structure 6, a condenser 7 and a pump 8a, and the condenser 7
is connected to the cooling tower 9 via a pump gb (z), and the power generated in the expansion mechanism 6 is supplied to the load 10.

FIG. 5 shows the configuration of the control device of the power generator shown in FIG.
A detector for solar radiation Q, 20 is an external temperature T, and a solar radiation tQ,
15 is an arithmetic circuit that calculates the optimum value 'I'o of the heat medium temperature on the inlet side of the heat collector 1 (the temperature indicated by the flat part of the broken line in FIGS. 1 to 3) from A setting device, 16 a detector for detecting the installation position "I"l of the low temperature heat storage tank 3b, 17 a corresponding circuit for the lower limit temperature IJIIL of the low temperature heat storage tank 3b, 18 a detector for the temperature T2 of the high temperature heat storage tank 3a ,1
9 is a setting circuit for the lower limit temperature T2L of the high temperature heat storage tank 3a; 21
21b is a comparator that outputs "0" if the solar radiation amount Q is larger than the reference solar radiation 1: Q o , and 21b is a comparator that outputs "0" when the solar radiation amount Q is larger than the reference solar radiation 1: Q o . Output “1” when high?Output “0” in other cases
A comparator that outputs full output, outputs ``1'' when the temperature of the 21c high temperature heat storage tank 3a is higher than its lower limit temperature ``J''2L, and outputs ``O'' in other cases. , 21d
sets the output to "1" when the optimum @To is higher than the temperature T+ of the low-temperature heat storage tank 3b, and sets the output to "0" in other cases.
”, the comparator 21e outputs “1” when the optimum value To is higher than the temperature T2+ of the high temperature heat storage tank 3a,
Comparators whose output is "0" in other cases, 22a to 22e
23 is an AND circuit, 24a to 24c are inverting circuits, and 25a.

25b is OR time IM, 26a and 26b are three-way valves 12a.

12b indicates the state of heat medium circulation by the low temperature heat storage tank 3b, 27a, 271) indicates the three-way valve 12a, ] 2b
28 indicates a state in which the heat medium is circulated in the heat collector 1, 29 indicates a state in which the heat medium is completely flowed through the bypass passage 40, and 30 indicates a state in which the heat medium is circulated through the bypass flow path 40.
excitation coils a and sb; 31 is a temperature difference detector between the optimum value To and the temperature TI of the low temperature heat storage tank 3b; 32 is a temperature difference detector between the optimum value To and the temperature T2 of the high temperature heat storage tank 3a;
33 voltage generation circuit, 34 rotation speed control section of pump 4,
35 is a constant voltage generating circuit.

Note that the voltage generating circuit 33 has characteristics as shown in FIG. That is, when the difference in temperature between the temperature T+, T2 of the heat storage tank 3a or 3b (i.e., the heat medium temperature on the inlet side of the heat collector 10) and the optimum value To is negative, the output voltage of the species with a large difference is lowered, and the TI , T2≧To, the output voltage is completely constant.

The pump 140 rotation speed control section 34 rotates at a rotation speed proportional to the output voltage.

Next, what is the operation of this embodiment? explain. First, the operation at startup,
This will be explained in relation to increased solar radiation. Solar radiation tQ increases to standard solar radiation IQ. When the signal becomes sharper than that, the output of the comparator 21a becomes "1", and the state 28 occurs, that is, the three-way valves 11a and 1l.
At the same time, the pump 4.8 is operated via the OR circuit 25bi to achieve a state in which the heat medium is circulated to the heat collector 1.
When a signal is applied to the excitation coil 30 for starting a and 8b, the pumps 4.8a and 8b are started, and the Rankine cycle 2 generates full power.

The heat medium circulation it at this time is determined as follows. Heat is collected in the calculation circuit 20 from the outside temperature T1 and the amount of solar radiation Q.
: i Perform all calculations of the appropriate value To of the heat medium temperature on the input side, and compare it with the temperature TI of the low temperature heat storage tank 3b and the temperature T of the high temperature heat storage tank 3a, ']"2>To>TI In this case, the output of the comparator 21d becomes 1# and the output of the comparator 21e becomes "O", so the output of the 1-AND circuit 22a becomes 1", and the three-way valve 12
a, 12be Heat medium circulation state 26a't: Realized by switching to the low temperature heat storage tank 3b side and circulating the heat medium to the low temperature heat storage tank 3b. At the same time, the AND circuit 22b opens and sends a signal corresponding to TI ToK, which is the output of the temperature difference detector 31, to the total voltage generation circuit 33, and outputs the signal to the rotation speed control section 34 of the pump 4.
A signal is transmitted to control the circulation amount to maximize exergy efficiency.

Next, the solar radiation tQ increases, and the optimum heat medium on the inlet side of the heat collector 10
[If T o becomes higher than the temperature T2 of the high-temperature heat storage tank 3a, the output of the comparison 1W21e becomes 1'', and the three-way valves 12a and 12bk are switched to realize the heat medium circulation state 27 af by the high-temperature heat storage tank 3a. At the same time, the output of the temperature difference detector 32, that is, a signal corresponding to T2-To is applied to the voltage generation circuit 33 through the AND circuit 22c?r.
A signal for one-cycle monkey welfare control is sent to the rotation speed control section 34.
L.

As shown in Figure 2, the equipment 1 explained so far is as follows:
When the optimal value To shown in the flat part of the broken line increases due to an increase in the solar radiation scene, the maximum value T is reached at the temperature T1 or T2' of the heat storage tank 3a or 3b (9). (by reducing the amount of heat medium circulation until the operating condition reaches the -C point), it is possible to realize an operating condition with low exergy efficiency.

When the amount of solar radiation begins to decrease, the relationship between the actual operating conditions and the optimal operating conditions becomes as indicated by point A and the broken line C in FIG. 3. That is, the temperature of the heat medium on the inlet side of the heat collector 1 (temperature T2 of the high-temperature heat storage tank 3a) is the same as the optimum temperature. At this time, the output of the comparator 21d becomes "1" and the output of the comparator 21e becomes "0", so the output of the AND circuit 22a becomes "■", and the state of 26a, that is, the heat medium by the low temperature heat storage tank 3b. Realize circulation. Furthermore, the solar radiation mQ decreases and becomes lower than the reference solar radiation amount Qo, and the thermal storage tank temperature TI or T2 is lower than the respective set lower limit temperature TIL or lp2. ,
If it is higher than , the output of the comparator 21a is "0" and the output of the comparator 6211) or 21c is "1", so the AND circuit 22f is
output becomes "1", and the three-way valves 11a and 1lb (i
7 Bypass flow path 40 side V (switching (101) Heat medium circulation state where no heat is collected but power is generated 29
Realize. At this time, the amount of heat medium circulating through the pump 4 is determined by a signal from the constant voltage generating circuit 35. At this time, in the heat storage tank used for heat medium circulation, when the temperature T2 of the high temperature heat storage tank 3a is higher than the set lower limit temperature T2L, the output of the comparator 21C is 1'' and the output of the comparator 21e is 0''. Since the output of the AND circuit 22e is 11n and the output of the AND circuit 22e is "1", the state a27b, that is, the high temperature storage tank 3a is reached, and the temperature T2 of the high temperature storage tank 3a is at the lower limit (clogging). Temperature higher than T2L and low temperature heat storage tank 3b
If the temperature Tl is still lower than the set lower limit IMf□lit,L, the output of the comparator 21b and the inverting circuit 24C becomes "1".
Then, the output of the AND circuit 22d becomes l'' and 72/), that is, K and V, and the state 26b, a+ts low-heat storage 3b.

Next, when the temperatures 1fTz and Tl of the heat storage tanks 3a and 3b both become lower than the set lower limit, all the signals entering the four-way circuit 25b are "0".
Therefore, the pumps 4, 8a, and 8b stop.

(11) According to this embodiment, it goes without saying that optimal operating conditions can be achieved in both cases of increase and decrease in the amount of solar radiation, and furthermore, even after the amount of solar radiation disappears, the surplus heat of the heat storage tanks 3a and 3b can be fully utilized. Power generation can be done fully effectively.

Although an embodiment using a total heat source of solar heat has been shown above, in the case of using a total heat source such as waste heat, all of the present embodiments can be applied by replacing the temperature with the total heat source temperature at a location corresponding to the amount of solar radiation.

-! In addition, the amount of heat medium circulation can be controlled not only by controlling the pump rotation speed as in the embodiment, but also by providing a bypass valve 7il in parallel with the heat medium circulation pump 4 and controlling the opening degree of each valve. I can do it. It is also possible to use the condensation temperature of Rankine cycle 2 instead of the outside temperature KT. In addition to the Rankine cycle, other power generating devices such as a refrigerator, a Freyton cycle, a Stirling cycle, etc. can also be used as the power generating means.

As described above, in the present invention, the heat collecting roof I
ICd heat 1fiA In addition to all of the multiple heat storage tanks with different degrees of heat, a detector that detects the thermal state of the heat source, the outside world, and the temperature of the heat storage tank (12) respectively, and the thermal state of the heat source and the outside world are used to detect the heat on the heat source population side. calculation means for calculating the optimum temperature of the medium temperature, means for flowing a heat medium circulation blade that maximizes the exergy rate based on the temperature difference between the optimum temperature and the detected value of the temperature of the heat storage tank; Not only can heat be collected with maximum exergy efficiency in response to fluctuations in the thermal conditions of the heat source and the outside world, but also the selection of heat storage tanks can accommodate fluctuations in the thermal conditions. Heat storage can be performed in a suitable state.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between the heat medium temperature at the collector inlet side and the amount of heat medium circulation in a solar heat collector, and the exergy efficiency.
The figure is equivalent to Figure 1 when the amount of solar radiation is high, and Figure 3 is the solar radiation)
Fig. 1 is a diagram corresponding to a case where there are few accents, Fig. 4 is a system diagram showing an embodiment of the present invention, Fig. 5 is a control block diagram of the embodiment, and Fig. 6 is a diagram of the voltage generating circuit used in the embodiment. It is a characteristic diagram. 1... Heat collector, 2... Rankine cycle, 3a...
- High temperature heat storage tank, 3b... Low temperature heat storage tank, 4... Heat medium circulation pump, (13) 21.12... Three-way valve, 13... Outside temperature detector,
14...Solar radiation amount detector, 16...Low temperature heat storage tank temperature detection device 18...High temperature heat storage tank temperature detector, 26...
Low-temperature heat storage tank heat medium circulation state, 27... Commercial temperature heat storage tank heat medium circulation state, 28... Heat collection state by heat collector, 29...
Heat collector bypass state, 30... Pump excitation coil, 3
1゜32... Temperature difference detector, 33... Voltage generation circuit,
34... Rotation speed control unit, 35... Constant voltage generation circuit. (14) Y 1 Drawing allowed 4 Drawing F

Claims (1)

[Claims] In the power generation device tT/C, which consists of a heat collection loop equipped with a heat source, a heat storage tank, and a heat medium circulation pump, and a means for converting the amount of heat collected in the heat collection loop into power, heat is stored in the heat collection loop. In addition to providing multiple heat storage tanks with different temperatures, we also need a detector that detects the thermal conditions of the heat source and the outside world as well as the temperatures of the heat storage tanks, and what is the optimal value for the temperature of the heat medium at the inlet of the heat source based on the thermal conditions of the heat source and the outside world? A calculation means for calculating, a means for circulating a heat medium to maximize exergy efficiency based on a temperature difference between the optimum value and a detected value of the temperature of the heat storage tank, and a means for selecting a heat storage tank based on the temperature difference. A power generation device with all the features.