JPH04203771A - Cooling device - Google Patents

Abstract

PURPOSE:To increase a thermal efficiency of an entire cold or hot heat source plant by a method wherein as a driving heat source, an absorption type freezer for taking out vapor from a low pressure vapor head of a heating vapor supplying device is provided, cold water is let flow in series to the absorption type freezer and a compression type freezer so as to enable a cooling to be attained. CONSTITUTION:A compressor 13 for a compression type freezer B is driven by a power force generated at a steam turbine 9 and then cold water is cooled with an evaporator 14. Heat removed from the cold water is transmitted to a cooling water 25 with a condenser 15. An absorption type freezer C takes driving vapor from a low pressure vapor header through a low pressure vapor pipe 12 so as to cool the cold water. Heat removed from the cold water is transmitted to a cooling water 24. Driving vapor gives heat to the absorption type freezer C and flows into a hot-well tank 22 as drain. The cold water is used as a cooling heat source for a heat demanding part 26, its temperature is increased and the cold water passes through a cold water return pipe 17, flows into the absorption type freezer C. The cold water is cooled down to an intermediate temperature, passes through a cold water pipe 18, further cooled with the evaporator 14 of the compression type freezer B, cooled down to a predetermined temperature and then the cold water is forcedly sent to the heat demand part 26 by a pump 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cooling device for a cold/hot heat source plant, and more particularly to a cooling device suitable for energy saving in a cold/hot heat source plant that is simultaneously subjected to a heating load and a cooling load.

[Conventional technology]

As shown in Refrigeration and Air Conditioning Technology, Vol. 16, No. 185, Page 1, in a conventional cooling system that combines a compression refrigerator and an absorption refrigerator, steam is passed through a steam turbine and then an absorption refrigerator. Steam is not extracted for other purposes between the outlet and the absorption chiller.

On the other hand, in chemical plants, high-pressure steam is generated in a boiler, and the steam is reduced in pressure to match the temperature level required by the plant and then supplied. A steam turbine has been installed in this pressure reducing section to recover power and save energy. In this case, the power that can be extracted from the steam turbine depends on the amount of steam consumed by the plant.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, steam is expanded by a steam turbine for driving a compressor, and all of the steam with power recovered flows into an absorption chiller. Therefore, power cannot be recovered from steam that is sent out under reduced pressure for heating. First, it was not possible to increase the thermal efficiency of the entire cold/hot heat source plant.

On the other hand, as shown in Figure 2, similar to chemical plants, etc.
When a steam turbine is installed during the depressurization process to send steam under reduced pressure for heating, and the power is recovered to drive a compression chiller, the power obtained from the steam turbine varies depending on the heating load, resulting in unstable refrigeration capacity. , the chilled water temperature at the outlet of the refrigerator is not constant.

In addition, the heating load and cold load applied to the cold heat source plant for district heating and cooling change as shown in Fig. 3, and the refrigerating capacity cannot be achieved when the cold load is large. Since there is little correlation between the cold load and the heat load and they change independently, the above-mentioned stability of the chilled water temperature at the outlet of the refrigerator cannot be expected.

An object of the present invention is to provide a cooling system that can eliminate the problems of the conventional technology, increase the thermal efficiency of the entire cold/hot heat source plant, and maintain a stable cold water outlet temperature without having the refrigeration capacity affected by the heating load. Our goal is to provide the following.

[Means to solve the problem]

The object is to provide an absorption refrigerator that extracts steam from a low-pressure steam head of a heating steam supply device as a driving heat source, and to provide the absorption refrigerator and the compression refrigerator with: This is achieved by allowing cold water to flow in a series for sequential cooling.

Further, in claim 1, the object is to provide a control device for controlling the steam to be sent out under reduced pressure, the compression refrigerator, and the absorption refrigerator, and to control the control device to control the steam to be sent out under reduced pressure when there is a large heating load. It is configured to be controllable so that the amount of steam flowing into the absorption chiller is reduced when the amount of steam is large, and the amount of steam flowing into the absorption chiller is increased when the heating load is low and the amount of steam to be sent under reduced pressure is small. This can be achieved even more precisely.

Furthermore, the above object is achieved even more reliably by making the amount of steam that can be vented by the steam turbine larger than the maximum steam consumption amount of the absorption chiller.

[Effect]

In the present invention, the amount of steam that can be ventilated by the steam turbine is made larger than the maximum steam consumption amount of the absorption chiller.

And a compression refrigerator driven by a steam turbine,
By flowing cold water in series to the absorption chiller and always using the cooling load less than the sum of the full-load refrigeration capacity of the two chillers, it is possible to change the load distribution to each chiller depending on the surrounding conditions. , it is possible to exhibit a predetermined refrigerating capacity as a whole.

For example, when the heating load is large and the amount of steam to be sent out under reduced pressure is large, the amount of steam vented to the steam turbine can be increased, reducing the amount of steam flowing into the absorption chiller, reducing the refrigeration capacity, and switching to the compression chiller. By increasing the load and recovering more power during the decompression process, significant energy savings can be achieved.

Specifically, if the high-pressure steam intalbee is the iH9 steam turbine output steam intalbee iro, the coefficient of performance C0PTB of the refrigerator is as follows.

The heat of the steam turbine exit steam from the steam turbine to the drain is used for heating.

In conventional condensing turbine-driven compression refrigerators, C0PTS
= 1.0 to 1.3, and the thermal efficiency is 4 times or more.

When the heating load is small and the amount of steam sent under reduced pressure is small,
Increasing the amount of steam flowing into the absorption chiller increases the refrigeration capacity of the absorption chiller and compensates for the decrease in the refrigeration capacity of the compression chiller. , the amount of steam vented to the steam turbine increases by the amount increased by the absorption chiller, the output of the steam turbine does not decrease in proportion to the heating load, and the reduction in the cooling capacity of the compression chiller is reduced. . Therefore, even if the heating load is reduced, the required refrigerating capacity can be maintained, and the chilled water outlet temperature is also stabilized.

In addition, when the heating load is small, a cooling system that combines a compression chiller and an absorption chiller has a thermal efficiency that is 20 to 30% higher than a general condensing turbine-driven centrifugal chiller or an absorption chiller, so it always maintains high efficiency. Able to drive.

A control device controls the amount of steam sent under reduced pressure from the low-pressure steam header side, the compression refrigerator, and the absorption refrigerator.

〔Example〕

Embodiments of the present invention will be described below with reference to FIG.

The cooling device of the embodiment shown in FIG. 1 includes a heating steam supply device A, a steam turbine 9, a compression refrigerator B, an absorption refrigerator C, a pressure-feeding cold water pump 16, and a control device. , a hot well tank 22 , and a boiler water suction pump 23 .

The low-pressure steam system of the heated steam supply bag atA, the compression refrigerator B, and the pressure-feeding cold water pump 16.

The absorption refrigerator C and the hot well dunk 22 are connected to a heat consumer 26 through wiring.

The heated steam supply device A includes a boiler 1, a ladder 3 connected to the boiler 1 via a steam pipe 2, a pressure reducing device 4 connected thereto via a low pressure steam pipe 5, and a ladder 3 connected to the boiler 1 via a low pressure steam pipe 5, and a ladder 3 connected to the boiler 1 via a steam pipe 2. It has a rudder 6.

The steam turbine 9 is connected in parallel with the vacuum bag @4 between the high pressure steam header 3 and the low pressure steam header 6 via a high pressure steam pipe 10 and a low pressure steam plumber 1.

The high-pressure steam pipe 10 is provided with a steam control valve 8 for a steam turbine.

The steam turbine 9 is provided with a governor 27 . The governor 27 controls the steam control valve 8 to keep the rotational speed of the steam turbine 9 constant.

The compression refrigerator B includes a compressor 13, a steamer 14,
It has a condenser 15. The compressor 13 is drivingly connected to the steam turbine 9 .

The evaporator 14 is connected to the absorption chiller C by a cold water pipe 18, and to the heat consumer 26 by a cold water pipe 19. A vane 30 is provided in the pipe connecting the evaporator 14 and the compressor 13 to control the suction capacity of the compressor. A vane drive actuator 31 controlled by a control device is connected to the vane 30. The condenser 15 is configured to transfer the heat taken from the cold water by the evaporator 14 to the condenser cooling water 25.

The pressure-feeding cold water pump 16 connects the evaporator 14 and the heat demander 2.
It is provided in a cold water outgoing pipe 19 connecting to 6.

The absorption chiller C is connected to the low pressure steam header 6 of the heating steam supply device A through the low pressure steam piping 12, is connected to the heat consumer 26 through the cold water return pipe F, and is further connected to the compression type through the cold water plumber 8. The refrigerator B is connected to the evaporator 14. Further, absorption chiller cooling water 24 is inserted into the absorption chiller C. A steam control valve 36 is provided in the low pressure steam pipe 12.

The control device includes a pressure detector 28 provided in the steam pipe 7 connecting the low-pressure steam ladder 6 and the heat demander 26, a pressure regulator 29 connected to the pressure detector 28, and a low selector 32.
It is constructed by having a cold water outlet temperature detection end 35 inserted into the cold water outgoing pipe 19, a temperature controller 34 connected to this, and a split control computing unit 33 connected to this temperature controller. There is. The split control computing unit 33
is connected to the low selector 32 and a steam control valve 36 provided in the low pressure steam pipe 12.

The low selector 32 is connected to a pressure regulator 29 , a split control computing unit 33 connected to a temperature regulator 34 , and a vane drive actuator 31 , and is connected to either the pressure regulator 29 or the temperature regulator 34 . It operates with a small signal value and sends a signal to the vane drive actuator 31.

The hot well tank 22 is connected to the inlet of the absorption chiller C via a drain pipe 22, and is also connected to a heat consumer 26 via a drain pipe 21. This real well tank 22 is connected to the boiler 1 via piping.
is connected to.

A boiler feed pump 23 is provided in this piping.

The cooling device of the above embodiment operates and functions as follows.

As a heat source for heating the heat consumer 26, high-pressure steam is reduced to a predetermined pressure (5 to 10 kg/L0iG) by the pressure reducing device 4 and then sent. A steam turbine 9 is connected in parallel with this pressure reducing device 4, and steam is preferentially flowed to recover the power for the pressure reducing process. When the heating demand of the heat consumer 26 is large, steam is also supplied from the pressure reducing device @4 to cope with the heating demand.

The power generated by the steam turbine 9 drives the compression refrigerator B.
The compressor 13 is driven, and the evaporator 14 cools the cold water.

The heat taken from the cold water is transferred to the cooling water 25 in the condenser 15.

On the other hand, the absorption chiller C takes in driving steam from the low pressure steam header 6 via the low pressure steam piping 12 and cools the cold water. The heat taken from the cold water is transferred to the cooling water 24. The driving steam gives heat to the absorption refrigerator C and flows into the hot well dunk 22 as a drain.

The chilled water is used as a heat source for cooling the heat consumer 26, and after increasing its temperature, passes through the chilled water return pipe F, first flows into the absorption chiller C, is cooled to an intermediate temperature, and passes through the chilled water pipe 18 to the compression chiller. After being further cooled by the steamer 14 of the refrigerator B and cooled to a predetermined temperature, the water passes through the cold water plumber 9 and is pumped to the heat demander 26 by the pressure pump 16.

The boiler 1 of the heating steam supply device A burns fuel to heat the water supplied from the boiler water supply pump 23 to produce high-temperature, high-pressure steam, and sends this steam to the high-pressure steam header 3 through the steam pipe 2. .

The amount of steam that can be vented from the steam turbine 9 side is set to be larger than the maximum steam consumption amount of the absorption chiller C.

When the heating load of the heat consumer 26 is large and the amount of heating steam sent is sufficiently larger than the required amount of steam for the steam turbine 9, the steam pressure of the ladder 6 to low pressure steam is determined by the pressure reducing device 4. The steam pressure at that time is adjusted in advance so that it is lower than the set value of the pressure regulator 29 in the control device. The pressure regulator 29 outputs a signal to fully open the vane 30 when the pressure detected by the pressure detector 28 is lower than a predetermined pressure, and when the pressure detected by the pressure detector 28 is higher than the predetermined pressure, the vane 30 is opened in proportion to the deviation from the predetermined pressure. Make sure to send a signal to close 30.

As described above, by adjusting the pressure regulator 29 of the pressure reducing device 4, when the amount of air supply for heating is large, the compression refrigerator B can adjust the opening degree of the vane 30 according to the signal from the pressure regulator 29. Since this is not controlled, the vane 30 is opened and closed by the signal from the temperature controller 34, and the cold water outlet temperature is controlled to be a predetermined temperature.

When the heating load is small and the amount of steam sent is small, even if the amount of steam passing through the pressure reducing device W4 is set to 0, if the amount of steam required by the steam turbine 9 is large, the pressure in the low pressure steam header 6 will rise.

When the pressure within the low pressure steam header 6 rises above a predetermined pressure, the pressure regulator 29 issues a closing signal to the vane 30. When the vanes 30 close, the load on the steam turbine 9 decreases and the rotational speed increases.

When the rotation speed increases, the governor 27 issues a signal to close the steam control valve 8 for the steam turbine so as to control the rotation speed to a constant range. In other words, when the vane 30 is opened or closed to increase or decrease the load on the compressor 13, the output of the steam turbine 9 changes, and the amount of steam passing through the steam turbine 9 changes, so the pressure inside the low-pressure steam header 6 can be controlled. .

When the vane 30 of the compressor 13 is closed to control the pressure of the ladder 6 to low-pressure steam, the capacity of the compression refrigerator B is reduced and the chilled water outlet temperature increases. As the chilled water outlet temperature increases, the temperature controller 34 signals to increase the refrigeration capacity.

The sprint control computing unit 33 receives the signal and issues a signal to open the vane 30 of the compressor 13 and also issues a signal to open the steam control valve 36 of the absorption chiller C. The vanes 30 of the compressor 13 are moved by the low selector 32 depending on the smaller signal from the pressure regulator 29 or the temperature regulator 34, so when the heating load is small, the vanes 30 are opened and closed by the signal from the pressure regulator 29.

Therefore, the steam control valve 36 opens so that the absorption chiller C covers the limited refrigeration capacity of the compression chiller B, thereby covering the refrigeration capacity and keeping the chilled water outlet temperature constant. .

By opening the steam control valve 36, the amount of steam flowing from the high pressure steam header 3 to the low pressure steam header 6 increases, so the amount of steam that can flow to the steam turbine 9 also increases, increasing the turbine output → refrigeration of the compression type refrigerator. Capacity will increase.

When the cooling load is small, the split control computing unit 33
Load is given to compression chiller B in preference to absorption chiller C to effectively utilize the power recovered in the steam depressurization process and increase thermal efficiency. By increasing the cooling capacity and stabilizing the chilled water outlet temperature by increasing the cooling capacity, it is possible to cope with changes in the amount of steam supplied due to increases and decreases in the heating load. It can also respond to changes in the cooling load. Furthermore, when the amount of steam supplied is large and the cooling load is small, the load is mainly applied to the compression refrigerator, resulting in high thermal efficiency.

〔Effect of the invention〕

According to the invention described in claim 1 of the present invention explained above,
An absorption refrigerator is provided as a driving heat source to extract steam from a low-pressure steam header of a heating steam supply device, and the absorption refrigerator and compression refrigerator are configured to be sequentially cooled by flowing cold water in series. Therefore, even if the amount of steam supplied changes due to a change in the heating load, the refrigeration capacity does not change, so the energy from the depressurization process of the heating steam can be used, which has the effect of increasing the thermal efficiency of the entire cold/hot heat source plant. Moreover, the refrigerating capacity is not affected by the heating load, and a stable cold water outlet temperature can be maintained.

Further, according to the second aspect of the present invention, a control device is provided for controlling the steam to be sent under reduced pressure, a compression refrigerator, and an absorption refrigerator, and the control device is controlled by a heating load. When the amount of steam to be sent under reduced pressure is large, the amount of steam flowing into the absorption chiller is reduced, and when the heating load is low and the amount of steam to be sent under reduced pressure is small, the amount of steam flowing into the absorption chiller is increased. Since it is configured to allow
This has the effect that each part can be controlled more accurately.

Furthermore, according to the third aspect of the present invention, the amount of steam that can be ventilated by the steam turbine is made larger than the maximum steam consumption of the absorption chiller, so that the thermal efficiency of the entire cold/hot heat source plant is improved. There is an effect that the cold water outlet temperature can be stabilized and maintained even more reliably.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of the present invention, FIG. 2 is a system diagram showing a conventional technique, and FIG. 3 is an explanatory diagram of heat load. A: Heating steam supply device, B: Compression refrigerator, C:
...Absorption chiller, D...Control device, 1...Boiler,
3... High pressure steam header, 4... Pressure reducing device, 6...
Low pressure steam header, 8... Steam control valve, 9... Steam turbine, 13... Compressor, 14... Evaporator, 15
・Condenser, 16...Cold water pump for pressure feeding, 22...Hotwell tank, 23...Boiler water supply pump, 26...
・Heat demander. 27... Steam turbine governor, 28... Pressure detector, 29... Pressure regulator, 30... Compressor vane, 3
DESCRIPTION OF SYMBOLS 1... Actuator for vane drive, 32... Low selector, 33... Arithmetic unit for split control, 34...
...Temperature controller, 35...Cold water outlet temperature detection end, 36
・・・Steamer 1st mouth 2nd figure

Claims (1)

[Claims] 1. A heating steam supply device having a boiler, a high pressure steam head, a pressure reducing device, and a low pressure steam head;
A cooling system including a steam turbine connected in parallel with a pressure reducing device between the low pressure steam heads, a compression refrigerator driven by the steam turbine, and a chilled water pump, in which steam is used as a drive heat source from the low pressure steam head. 1. A cooling device characterized by being provided with an absorption refrigerating machine to be taken out, and configured to be able to sequentially cool the absorption refrigerating machine and the compression refrigerating machine by flowing cold water in series. 2. A control device is provided to control the steam to be sent out under reduced pressure, the compression refrigerator, and the absorption refrigerator. Claim 1 characterized in that it is configured to be controllable so as to reduce the amount of steam flowing into the absorption chiller and increase the amount of steam flowing into the absorption chiller when the heating load is low and the amount of steam to be sent under reduced pressure is small. cooling system. 3. The cooling device according to claim 1, wherein the amount of steam that can be vented by the steam turbine is larger than the maximum steam consumption amount of the absorption chiller.