JPH0979796A - Method and device for cleaning plate type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sufficient cleaning effect without generating any public polution by switching sea water into hot-water, manufactured by utilizing solar heat, to supply and circulate it upon washing and, further, by blowing pressurized air into the hotwater at the inlet port of a plate type heat exchanger to supply the air. SOLUTION: The temperature of water in a hot-water tank 6 is increased to a temperature, capable of sterilizing microbes, through an electric heater 7a by a power generated in a solar battery 7b. According to this method, hot-water in the hot-water tank 6 is circulated and supplied into the flowing pipeline route 3 at the sea water side of a plate type heat exchanger 1 by a hot-water circulating pump 8 for a predetermined period of time. Pressurized air is poured by a pressurized air pouring means 9 during or after finishing the hot-water circulation. According to this method, microbes, adhered to a plate, are perished by hotwater and are removed by separating them by the bubbling effect of the pressurized air to recover heat transfer performance and flow performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cleaning a plate heat exchanger for exchanging heat between seawater and other fluids.

[0002]

2. Description of the Related Art For example, in a plate heat exchanger using seawater as cooling water, there is a problem that microorganisms (shellfish, algae, fungi, etc.) in seawater adhere to the plate and grow, thereby impairing heat transfer performance and fluidity performance. is there. In order to prevent adhesion of marine microorganisms, conventionally, chemical treatment such as chlorine injection has been widely performed.

[0003]

However, the above-mentioned chemical treatment such as chlorine injection is not harmless at all and may cause environmental damage.

On the other hand, microorganisms in seawater can be easily killed by hot water, and in fact, hot water sterilization is adopted as a pollution-free cleaning method in condensers of power plants overseas. .

However, in this method, an electric heater, steam or the like is used as a heat source for producing hot water, and the energy cost for heating the water is high.

Further, the conventional hot water sterilization method has a problem that a sufficient cleaning effect cannot be obtained even if it is directly applied to a plate heat exchanger having many contact points inside.

An object of the present invention is to reduce the energy cost when raising the temperature of hot water, and to perform heat exchange between seawater and other fluids which is pollution-free and has a sufficient cleaning effect. An object of the present invention is to provide a cleaning method and device for a heat exchanger.

[0008]

In order to achieve the above object, the method of the present invention is a plate type heat exchanger for exchanging heat between seawater and other fluids.
Seawater is switched to hot water produced by utilizing solar heat for supply circulation, and pressurized air is blown into the hot water at the inlet side of the plate heat exchanger for supply.

With the above structure, the hot water generated by solar heat kills the microorganisms in the seawater adhering to the seawater side flow passage in the plate heat exchanger, and the pressurized air blown into the hot water supplies An air bubbling action is generated in the seawater-side flow path of the plate heat exchanger, so that marine microorganisms attached to the plate can be positively removed.

Further, the apparatus of the present invention is a plate heat exchanger for exchanging heat between seawater and other fluids, and is branched and connected to a distribution pipe path of seawater through a path switching valve. A circulating supply route of hot water, an electric heater that uses a solar cell installed in a hot water tank of the circulating supply route of the hot water as a power source, and an inlet side of a plate heat exchanger in the middle of the circulating supply route of the warm water And a means for injecting the pressurized air described above.

With this construction, the electric heater is heated by the electricity generated by the solar cell to produce hot water, and when this hot water is used for washing, the seawater is turned into hot water in the seawater side flow passage in the plate heat exchanger. It is possible to switch and circulate and supply pressurized air into the warm water at the inlet side of the plate heat exchanger.

Further, the apparatus of the present invention is a plate type heat exchanger for exchanging heat between seawater and other fluids, which is branched and connected to a distribution pipe path of seawater through a path switching valve. Circulating supply route of hot water, a solar heat collector for directly circulating and heating water in a hot water tank of the circulating supply route of hot water through a pipe, and a plate heat exchanger in the middle of the circulating supply route of hot water And a means for injecting pressurized air installed on the inlet side of the.

With the above construction, when washing is performed using the hot water that has been collected by the solar heat collector and heated, the seawater is circulated and supplied to the seawater side flow passage in the plate heat exchanger by switching to the hot water.
In addition, pressurized air can be blown into and supplied to the warm water on the inlet side of the plate heat exchanger.

Further, the apparatus of the present invention is a plate type heat exchanger for exchanging heat between seawater and other fluids, which is branched and connected to a distribution pipe path of seawater through a path switching valve. A circulation supply route of hot water, a heat storage tank using a solar heat collector as a heat source, a pre-stage heat exchanger that heats and evaporates a heat medium using the hot water of the heat storage tank as a heat source, and a heat medium that is heated and evaporated by the pre-stage heat exchanger. A solar heat pump system composed of a post-stage heat exchanger that heats the circulating hot water in the circulating supply route of the hot water by using it as a heat source by compressing with a compressor, and a plate heat exchanger in the middle of the circulating supply route of the hot water. And means for injecting pressurized air installed on the inlet side.

With the above structure, the hot water, which has been collected by the solar heat collector and heated, is stored in the heat storage tank, and the heat medium is heated and evaporated through the pre-stage heat exchanger, and the heat medium is compressed. In the latter stage heat exchanger, the hot water is circulated and supplied to the seawater distribution piping path by heating, and at the time of cleaning, this hot water is circulated and supplied by switching to the seawater side flow path in the plate heat exchanger,
In addition, pressurized air can be blown into and supplied to the warm water on the inlet side of the plate heat exchanger.

[0016]

1 to 3 show the first to third embodiments of the present invention.
1 is a schematic configuration diagram showing an embodiment, 1 is a plate heat exchanger, 2 is a distribution pipe path for a counterpart fluid (for example, water or other fluid), 3 is a sea water distribution piping path, and 4 is hot water circulation. Supply paths 5a, 5b, 5c, 5d are path switching valves,
6 is a hot water tank, 7 is a means for producing hot water using solar heat, 8 is a hot water circulation pump, and 9 is a means for injecting pressurized air.

The plate-type heat exchanger 1 is constructed so that the fluid of the opposite side and the seawater can be circulated in the respective circulation piping paths 2 and 3 for heat exchange.

A circulation supply route 4 of hot water is provided in the distribution pipe route 3 on the seawater side, and route switching valves 5a, 5b, 5c, 5 are provided.
It is branched and connected via d.

In the hot water circulation supply path 4, the hot water in the hot water tank 6 is switched by the hot water circulation pump 8 by switching the path switching valves 5a, 5b, 5c and 5d at the time of cleaning. It is configured to be supplied to the side distribution pipe path 3 and then to be refluxed to the hot water tank 6.

Path switching valves 5a, 5b, 5c, 5d
Are configured to perform a switching operation in relation to each other, and in a normal operating state, the valves 5a and 5b are opened, the valves 5c and 5d are closed, and at the time of cleaning,
The valves 5a and 5b are closed and the valves 5c and 5d are opened.

In the first embodiment, an electric heater 7a is installed in the hot water tank 6, and the solar cell 7 is attached to the electric heater 7a.
b is connected by an electric wiring 7c, and is controlled so that hot water having a temperature capable of sterilizing microorganisms in seawater (for example, a temperature of about 60 ° C.) can be supplied during cleaning.

In the second embodiment, in order to directly heat the water in the hot water tank 6 by the solar heat collector 7d and raise the temperature, the circulation pump 7e circulates the water through the pipe 7f.

In the third embodiment, in order to indirectly heat and raise the temperature of the water in the hot water tank 6 by the solar heat collector 7d, the circulation pump 7e circulates the hot water through the pipe 7f and the heat storage tank 7g. The hot water stored in the heat storage tank 7g is circulated and supplied to the upstream heat exchanger 7j through the pipe 7i by the circulation pump 7h to heat and evaporate the heat medium, and the heat medium is compressed by the compressor 7k. Supply heat to the rear heat exchanger 7n via the pipe 7m, and the heat medium is condensed in the rear heat exchanger 7n to heat and raise the temperature of the hot water circulating in the hot water circulation supply path 4. The solar heat pump system 7p is configured.

The warm water circulation pump 8 is driven for a predetermined time (for example, 3 minutes) at the time of cleaning, and is driven and controlled by manual control or automatic control by a timer or the like.

The means 9 for injecting pressurized air is installed in the middle of the hot water circulation supply path 4 between the inlet of the plate heat exchanger 1, the outlet of the hot water circulation pump 8 and the path switching valve 5c. Then, it is connected to a pressurized air supply source (not shown) such as a compressor via an appropriate control valve.
The pressurized air injecting means 9 is for injecting the pressurized air into the warm water for a predetermined time by opening the control valve at the time of cleaning, during the circulation of the warm water by the warm water circulation pump 8 or after the completion. With this pressurized air, an air bubbling state can be generated in the distribution pipe path 3 on the seawater side of the plate heat exchanger 1, whereby microorganisms adhering to the plate, in particular, adhering to the contact points of the plate. It is possible to reliably remove even microorganisms.

The embodiment of the present invention is constructed as described above, and its operation will be described below. In a normal operating state, the path switching valves 5a and 5b are opened and the valves 5c and 5d are opened.
Is closed, and the mating fluid and the seawater are mutually heat-exchanged in the plate heat exchanger 1. When the microorganisms in seawater adhere to and grow on the plate as the operating time elapses, and the heat transfer performance and the flow performance of the plate heat exchanger 1 deteriorate, switching to cleaning is performed. That is, the path switching valve 5
A and 5b are closed, valves 5c and 5d are opened, and the hot water circulation pump 8 is driven.

In the case of the first embodiment, the water temperature in the hot water tank 6 is raised to the sterilizable temperature of the microorganism by the electric power generated by the solar cell 7b via the electric heater 7a. A switch may be installed in the middle of the electric wiring 7c to stop energization when unnecessary, or ON / OFF control may be performed by the hot water temperature in the hot water tank 6.
As a result, the hot water in the hot water tank 6 is circulated and supplied by the hot water circulation pump 8 into the circulation pipe path 3 on the seawater side of the plate heat exchanger 1 for a predetermined time. Then, the pressurized air is injected by the pressurized air injecting means 9 during or after the circulation of the hot water. Thereby, the microorganisms attached to the plate can be killed by the warm water, and can be peeled and removed by the bubbling action of the pressurized air, so that the heat transfer performance and the flow performance can be recovered. After the cleaning is completed, the operation is returned to the normal operation, and the heat exchange operation is performed between the seawater and the partner fluid. The above cleaning may be performed regularly or at any time.

Further, in the case of the second embodiment, the circulating pump 7e is appropriately driven during the daytime and the water in the hot water tank 6 is sent to the solar heat collector 7d to be heated and heated, and this hot water is used. Then, as in the first embodiment, the inside of the distribution pipe path 3 on the seawater side of the plate heat exchanger 1 is cleaned. Circulation pump 7e of the solar heat collector 7d of the second embodiment.
May be ON-OFF controlled by the hot water temperature in the hot water tank 6.

Further, in the case of the third embodiment, as in the second embodiment, the circulating pump 7e is appropriately driven during the daytime to produce hot water by the solar heat collector 7d, and this is stored in the heat storage tank 7g. Is to store heat. And when cleaning,
Circulation pump 7h of rear heat exchanger 7j and rear heat exchanger 7
n compressor 7k is driven together with the hot water circulation pump 8, and first, the heat medium is heated and vaporized by the hot water in the heat storage tank 7g in the pre-stage heat exchanger 7j to be gasified, and the heat medium is compressed by the compressor 7k. After condensing and further raising the temperature, the hot water circulated by the hot water circulating pump 8 is heated and raised by the heat medium in the post-stage heat exchanger 7n, and the hot water is utilized to the first and second embodiments. Similarly, the inside of the distribution pipe path 3 on the seawater side of the plate heat exchanger 1 is cleaned. The circulation pump 7e of the solar heat collector 7d of the third embodiment may be ON-OFF controlled by the hot water temperature in the heat storage tank 7g. The front heat exchanger 7j and the rear heat exchanger 7n are preferably plate heat exchangers, but may be of other types.

In each of the above embodiments, hot water was circulated through the seawater side during cleaning. At this time, the other side is preferably empty in order to reduce the heat loss of the hot water, but it is full. Is also possible. In addition, circulation of hot water may be performed on both sides of the seawater side and the partner side. In this case, the same path switching valve and piping as those on the seawater side are branched and installed in the distribution piping path 2 for the counterpart fluid. In addition, each embodiment of the present invention,
May be used in combination with conventional hot water production means using commercial power,
In this case, the temperature rise time can be shortened and the energy cost at the time of temperature rise can be reduced. In the embodiment, the pressurized air injection means 9 is provided on the upstream side of the path switching valve 5c, but may be provided on the downstream side of the path switching valve 5c. Further, when circulating hot water to the seawater side during cleaning, drain the seawater from the plate heat exchanger 1 in advance,
It is preferable to pass hot water, but it is also possible to pass hot water without draining.

[0031]

According to the cleaning method of the present invention, the energy cost at the time of temperature rise is reduced, and the microorganisms in seawater attached to the seawater-side flow path in the plate heat exchanger are killed by warm water. In addition, the pressurized air supplied by being blown into the warm water causes an air bubbling action in the seawater side flow path of the plate heat exchanger, which can actively remove and remove marine microorganisms attached to the plate. It can recover the thermal performance and the flow performance without causing pollution.

Further, according to the cleaning apparatus of the present invention, hot water is produced by the generated power of the solar cell or the heat collecting action of the solar heat collector, and the hot water is directly or indirectly utilized to wash the hot water during the plate type cleaning. Seawater can be circulated and supplied to the seawater-side flow passage in the heat exchanger by circulating the hot water, and pressurized air can be blown into the hot water at the inlet side of the plate heat exchanger to be supplied.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a third embodiment of the present invention.

[Explanation of symbols]

 1 Plate Heat Exchanger 2 Distribution Pipeline for Fluid on Other Side 3 Distribution Pipeline for Seawater 4 Circulation Supply Route for Hot Water 5a to 5d Route Switching Valve 6 Hot Water Tank 7 Hot Water Production Means for Utilizing Solar Heat 7b Solar Cell 7d Solar Heat Collector 7g Heat storage tank 7j Pre-stage heat exchanger 7n Post-stage heat exchanger 8 Hot water circulation pump 9 Pressurized air injection means

Claims (4)

[Claims] 1. A plate-type heat exchanger for exchanging heat between seawater and another fluid, wherein during cleaning, seawater is switched to hot water produced by utilizing solar heat and circulated,
A method for cleaning a plate heat exchanger, characterized in that pressurized air is blown into and supplied into the warm water on the inlet side of the plate heat exchanger. 2. A plate heat exchanger for exchanging heat between seawater and another fluid, comprising: a circulation supply path for hot water branch-connected to a distribution piping path for seawater through a path switching valve. An electric heater using a solar cell as a power source installed in a hot water tank of the hot water circulation supply path, and a pressurized air installed on the inlet side of the plate heat exchanger in the middle of the hot water circulation supply path. An apparatus for cleaning a plate heat exchanger, comprising: an injection unit. 3. A plate heat exchanger for exchanging heat between seawater and another fluid, comprising: a circulating supply path for hot water branch-connected to a distribution pipe path for seawater via a path switching valve. A solar heat collector for directly circulating and heating water in a hot water tank of the hot water circulation supply path through a pipe, and installed at the inlet side of the plate heat exchanger in the middle of the hot water circulation supply path And a means for injecting pressurized air, the apparatus for cleaning a plate heat exchanger. 4. A plate heat exchanger for exchanging heat between seawater and other fluids, wherein a circulation supply path for hot water diverged to a distribution piping path for seawater through a path switching valve. , A heat storage tank using a solar heat collector as a heat source, a pre-stage heat exchanger that heats and evaporates a heat medium using hot water in the heat storage tank as a heat source, and a heat medium heated and evaporated by the pre-stage heat exchanger is compressed by a compressor A solar heat pump system composed of a post-stage heat exchanger that heats the circulating hot water in the circulating supply path of the hot water using this as a heat source, and was installed on the inlet side of the plate heat exchanger in the middle of the circulating supply path of the hot water. A cleaning device for a plate heat exchanger, comprising: means for injecting pressurized air.