JP2011117647A - Operational availability reducing system for existing boiler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system capable of reducing operational availability of an existing boiler. <P>SOLUTION: The system includes: a hot water storage tank 10 connected to a water supply line 2 and a hot water supply line 3 sending out hot water of the existing boiler 1 and capable of receiving water through the water supply line 2 and of supplying hot water through the hot water supply line 3; a heat recovery unit 20 recovering heat of drain hot water discharged from a facility; and a heat pump unit 30 having a heat absorbing means absorbing heat recovered by the heat recovery unit 20 and transferring the heat to a heating medium, a compression means compressing the heating medium, a heating means heating water received by the hot water storage tank 10 by using the compressed heating medium to generate hot water and returning the hot water to the hot water storage tank 10 and an expansion means expanding the compressed heating medium and supplying the expanded heating medium to the heat absorbing means. Hot water generated in the hot water storage tank 10 is supplied to the existing boiler 1 through the water supply line 2 and is heated to a predetermined temperature by the existing boiler 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a system that reduces the operating rate of an existing boiler using a heat pump unit.

  In hospitals, recreational facilities, hotels, leisure facilities, etc., boilers are used as hot water supply devices. This boiler is a device that burns fuels such as heavy oil, light oil, LPG, city gas, etc., and heats water by giving heat generated thereby.

  However, since the boiler generates carbon dioxide by burning fuel and discharges it into the atmosphere, it causes air pollution and global warming. For this reason, it is required to reduce the amount of fuel consumed and the amount of discharged carbon dioxide.

  Then, the technique which warms boiler feed water with the heat | fever which was stored in the warm drainage tank and was heat-recovered with the heat exchanger from the warm drainage is proposed (refer patent documents 1 and 2). . According to this technology, since the boiler feed water can be supplied to the boiler after heating, the amount of heat required for heating in the boiler can be reduced, and fuel consumption and carbon dioxide emission are reduced. be able to.

JP 2004-85067 A JP-A-7-55250

  In a facility where a boiler is already installed, the boiler is used as a hot water supply device unless there is a problem due to aging. However, since the boiler has the problems of air pollution and warming as described above, it is desirable to reduce the operating rate of the boiler as much as possible.

  From this point of view, the above-described techniques have been proposed in the past. However, these techniques cannot sufficiently reduce the operating rate of the boiler only by using the hot wastewater as auxiliary energy for boiler supply water.

  Therefore, it has been desired to provide a system that can sufficiently reduce the operating rate of an existing boiler while ensuring a sufficient amount of hot water to be used in a facility or the like.

  As a result of intensive studies, the inventor of the present invention generates hot water of a predetermined temperature using a heat pump unit, and gives the heat of the warm drainage discharged from the facility to the heat pump unit. By effectively using it, the power consumption of the heat pump unit can be reduced and the operating rate of the existing boiler can be greatly reduced. As a result, the running cost of the existing boiler and the emission of carbon dioxide, which is a warming gas Has also been found to be significantly reduced.

  This invention is made | formed by discovering these things, The said subject can be solved by providing the operating rate reduction system of the existing boiler of this invention.

  This system is connected to a water supply line of an existing boiler and a hot water supply line that delivers hot water generated by heating, and is capable of receiving water through the water supply line and supplying hot water through the hot water line. A heat recovery unit that recovers the heat of the hot wastewater discharged from the facility, a heat absorption means that absorbs the heat recovered by the heat recovery unit and applies the heat to the heat medium, and a compression means that compresses the heat medium; Heating means that heats the water received by the hot water storage tank by the compressed heat medium, generates hot water and returns the hot water tank to the hot water storage tank, and expansion means that expands the compressed heat medium and supplies it to the heat absorption means Including a heat pump unit.

  It can be installed simply by connecting the hot water storage tank to the water supply line and hot water supply line of the existing boiler, connecting the heat recovery unit to the hot drain line of the facility, and installing a heat pump unit between them. In addition, by recovering heat from hot wastewater and supplying the heat to the heat pump unit, the power consumption of the heat pump unit can be suppressed, and the coefficient of performance (COP) used as a measure of energy consumption efficiency can be improved. In addition, hot water can be generated, and the generated hot water can be supplied to the temperature raising circuit of the existing boiler to reduce the operating rate of the existing boiler.

  Moreover, the reduction of the operation rate of the existing boiler can reduce the running cost of the boiler and reduce the emission amount of carbon dioxide which is a greenhouse gas. The hot waste water can be used for snow melting after heat recovery is performed by the heat exchange unit, and after being purified by the septic tank, it can be sent to the public sewer.

  The heat recovery unit includes a heat exchange unit that gives heat of the warm wastewater to circulating water. The heat recovery unit further includes a heat storage unit for storing hot water, and gives heat of the circulating water heated by the heat exchange unit to the hot water in the heat storage unit. The warm water is sent to the heat pump unit, and the heat of the warm water is given to the heat medium. The circulating water is circulated between the heat exchange unit and the heat storage unit by a circulation means.

  In addition, the system may further include a warm drain tank that receives and stores the warm drainage discharged from the facility, and a drainage unit that supplies the stored warm drainage to the heat recovery unit.

The figure which showed one structural example of the operating rate reduction system of the existing boiler. The figure which showed one structural example of the heat recovery unit with which the system shown in FIG. 1 is provided. The figure which showed the structural example of the heat pump unit with which the system shown in FIG. 1 is provided. The figure which showed another structural example of the operating rate reduction system of the existing boiler.

  The system for reducing the operating rate of the existing boiler according to the present invention reduces the operating rate while using the existing boiler, and discharges carbon dioxide that is a cause of global warming discharged from the boiler running cost and the boiler. It is an apparatus that can reduce the amount.

  FIG. 1 is a diagram showing one configuration example of an operating rate reduction system for an existing boiler. This system includes a hot water tank 10 connected to a water supply line 2 for supplying water to the existing boiler 1 and a hot water supply line 3 for supplying hot water generated by the existing boiler 1.

  The hot water storage tank 10 is a newly installed tank, and can be connected to each of the water supply line 2 and the hot water supply line 3 by providing a branch pipe in the middle of each of the water supply line 2 and the hot water supply line 3.

  The hot water storage tank 10 is a container capable of storing a predetermined amount of hot water, and is connected to a water supply nozzle connected to the water supply line 2, a hot water supply nozzle connected to the hot water supply line 3, and a heat pump unit 30 described later. There are four nozzles: a nozzle for supplying the received water and hot water stored therein, and a nozzle for receiving the hot water heated back by the heat pump unit 30. In addition, when the hot water storage tank 10 is installed outdoors, a heat insulating material or the like is wound around the outer surface so that the stored hot water is not cooled by heat dissipation.

  The hot water storage tank 10 can be equipped with a thermometer so that the temperature of the hot water inside can be measured, and can be equipped with a liquid level gauge (level gauge) so that the amount of remaining hot water can be measured.

  The system also includes a heat recovery unit 20 that recovers the heat of the hot wastewater discharged from the facility that uses the existing boiler 1. The facilities that use the existing boiler 1 include hospitals, recreational facilities, hotels, leisure facilities, etc. In these facilities, hot water is used for bathtubs, showers, pools, heating, etc. It becomes warm drainage. This warm wastewater is discharged at a temperature of about 30 ° C., and since the temperature is higher than that of normal temperature water, heat is recovered by the heat recovery unit 20.

  The warm wastewater is discharged after removing relatively large suspended matter with a hair catcher or the like. However, since fine suspended matter or the like is present, if it is supplied to the heat pump unit 30 as it is, a large number of fins provided in the heat pump unit 30 are provided. During that time, the floating substance adheres, and the heat absorption efficiency of the heat pump unit 30 is greatly reduced. For this reason, the heat recovery unit 20 is provided, and the heat recovered by the heat recovery unit 20 is applied to the heat pump unit 30.

  For example, as shown in FIG. 2, the heat recovery unit 20 circulates the circulating water with the heat pump unit 30 and includes a heat exchange unit 21 so that the heat of the hot wastewater is given to the circulating water. Can do. The heat exchange unit 21 may employ a coil-type heat exchanger, a double-tube heat exchanger, a multi-tube heat exchanger, or the like known so far.

  In the example of the heat recovery unit 20 shown in FIG. 2, the heat exchange unit 21 is not immersed in the heat exchanger as described above, but is immersed in one bathtub 21a and circulating water 22 stored in the bathtub 21a. It comprises a tube 21b through which drainage flows. The tube 21b has two curved portions, and the hot drain enters into a tube installed near the water surface, and is installed in one curved portion, an intermediate depth tube, another curved portion, and near the water bottom. It is structured and arranged to be discharged through the tube.

  Moreover, circulating water is supplied to the lower part of the bathtub 21a, and is taken out by the circulation pump from the upper part of the bathtub 21a. In the state where the convection hardly occurs, the circulating water 22 in the bathtub 21a has a high temperature near the water surface and a low temperature near the water bottom in relation to the density. If this state is created and circulating water in the vicinity of a high-temperature water surface can be supplied to the heat pump unit 30, the power consumption of the heat pump unit 30 can be suppressed, and heat recovery can be performed efficiently. Therefore, in FIG. 2, as described above, the hot waste water having the highest temperature is caused to flow near the water surface to raise the temperature near the water surface, and the circulating water near the water surface is supplied to the heat pump unit 30. The warm water drains from the surface of the water to the bottom of the water and returns the circulating water whose temperature has dropped to the vicinity of the bottom of the water, so that the circulating water is pushed up to the surface of the water and heated from the warm water to gradually raise the temperature. Has created a state that hardly occurs.

  In order to recover the heat of the hot water drainage as much as possible, the tube 21b is made long enough to have a sufficient heat transfer area, and the circulating water inlet nozzle and the hot water outlet outlet nozzle are adjacent to each other. A structure in which the outlet nozzle and the inlet nozzle of the warm waste water are disposed adjacent to each other is preferable. By adopting such a structure, heat can be recovered from the warm waste water at about 30 ° C., the circulating water can be set at about 28 ° C., and supplied to the heat pump unit 30 to give the heat.

  Since the material used for the tube 21b of the heat exchange unit 21 is a relatively low temperature such as about 30 ° C., plastic resin such as polyvinyl chloride, carbon steel, etc. can be used. As the material of the bathtub 21a, plastic resin such as FRP, carbon steel, or the like can be used. However, since the hot waste water contains soap, detergent, other floating substances, etc., the material of the tube 21b is preferably a plastic resin that hardly corrodes.

  In the example shown in FIG. 2, the number of the curved portions is two, but may be three or more, and may be composed of a plurality of tubes. Furthermore, a large number of fins may be provided on the outer surface of the tube.

  Referring again to FIG. 1, the system further includes a heat pump unit 30. The heat pump unit 30 receives the heat recovered from the hot waste water by the heat recovery unit 20, applies it to the heat medium circulating inside, and raises the temperature by compressing the heat medium, and the heat of the heat medium having reached the high temperature. It is an apparatus for generating hot water by heating it by giving it to the water in the hot water tank 10.

  Specifically, referring to FIG. 3, the heat pump unit 30 is driven by being supplied with heat absorption means 31 that obtains heat from the heat recovery unit 20 that has recovered the heat of the hot wastewater and gives it to the heat medium, Compression means 32 for compressing the heat medium, heating means 33 for heating the water received by the hot water tank 10 by the compressed heat medium, generating hot water and returning it to the hot water tank 10, and expanding the compressed heat medium And expansion means 34 for supplying heat to the heat absorption means 31. The heat pump unit 30 is preferably installed in the vicinity of the hot water tank 10 so that hot water generated by heating does not cool.

  The heat absorption means 31 receives the circulating water sent from the heat recovery unit 20 shown in FIG. 2, transmits the received circulating water heat to the heat medium, and warms the heat medium. Therefore, the heat absorption means 31 includes a heat exchanger that exchanges heat between the circulating water and the heat medium, and causes the heat medium to flow in the pipe, and the circulating water is brought into contact with the pipe so that the heat of the circulating water is the heat medium in the pipe. Give to. In order to improve the heat conduction efficiency in the heat exchanger, the heat transfer area can be increased. For example, a tube through which a heat medium flows can be formed in a coil shape, or fins can be provided on the surface of the tube. As the heat medium, a gas that can take a large compression ratio and greatly increases in temperature due to the compression is preferable, and examples thereof include air and carbon dioxide.

  The compression unit 32 compresses the heat medium warmed by the heat absorption unit 31. Since the compression performed by the compression means 32 is polytropic compression close to adiabatic compression, the discharge temperature rises depending on the compression ratio. For example, when air is used as the heat medium and air of about 0.1 MPa and about 20 ° C. is compressed to about 0.7 MPa, if there is no heat exchange with the outside, all the energy applied for the compression is all The temperature rises to about 260 ° C. in theory, but in reality, there is a heat loss, which is about 170 to 200 ° C. Although there is a heat loss, the temperature is higher than 100 ° C., so that water can be sufficiently heated. As the compression means 32, a volumetric compressor is preferable, and examples thereof include a reciprocating compressor and a diaphragm compressor.

  The heat medium thus compressed and brought to a high temperature is sent to the heating means 33 and gives the heat to the water received by the hot water tank 10. The heating means 33 can be a heat exchanger and can be coiled or provided with fins in order to increase the heat transfer area.

  The heat medium whose temperature is lowered by applying heat to the water in the heating means 33 is maintained in a compressed state, and the temperature does not decrease below the temperature of the hot water stored in the hot water storage tank 10. Thus, the heat absorption means 31 cannot absorb the heat of the circulating water. Therefore, the temperature is expanded by the expansion means 34 to lower the temperature. As the expansion means 34, an expansion valve can be used. In the expansion means 34, when the pressure is increased from about 0.1 MPa to about 0.7 MPa by the compression means 32, the pressure can be reduced from about 0.7 MPa to about 0.1 MPa.

  Referring again to FIG. 1, the heat pump unit 30 generates hot water of about 40 ° C. to about 50 ° C. in the hot water storage tank 10. This hot water can be sent directly to the bathroom or the like, but can also be sent to the existing boiler 1 through the water supply line 2 by the water supply pump 4 and further heated and then sent through the hot water supply line 3. For this reason, the water supply line 2 is provided with a valve for stopping water supply from the water supply source, and the hot water supply line 3 is provided with a valve for preventing hot water from the existing boiler 1 from returning to the hot water storage tank 10. Can be provided.

  When the boiler feed water is directly warmed with hot waste water of about 30 ° C., it can only be heated to about 25 ° C., and therefore it is necessary to perform considerable heating with the existing boiler 1. By adopting a configuration including the recovery unit 20 and the heat pump unit 30, it is possible to heat to about 40 to about 50 ° C., and when the hot water can be supplied as it is, heating by the existing boiler 1 is unnecessary. Even if it heats to 90 degreeC, the operation rate of the existing boiler 1 can be reduced significantly.

  The reduction in the operating rate of the existing boiler 1 can reduce the amount of fuel consumed and the amount of exhausted combustion exhaust gas. As a result, the amount of carbon dioxide, which is a warming gas, is reduced. be able to. In addition, the running cost of the existing boiler 1 can be reduced.

  FIG. 4 is a diagram showing another configuration example of the operating rate reduction system of the existing boiler. This system also includes a hot water tank 10, a heat recovery unit 20, and a heat pump unit 30, but the configuration of the heat recovery unit 20 is different from the configuration shown in FIG. I have. And it is set as the structure by which the warm waste water after heat | fever collection | recovery is used for snow melting, is purified in the septic tank 50, and is sent to a public sewer after that.

  In the embodiment shown in FIG. 1, the warm drainage discharged from the facility is sent to the heat recovery unit 20. In the embodiment shown in FIG. 4, the warm drainage is once collected in the warm drainage tank 40. 40 is sent to the heat recovery unit 20 by the hot drain pump 41. The warm drainage tank 40 precipitates suspended matter and the like contained in the warm drainage, and allows the warm water from which the suspended matter and the like are removed to be sent to the heat recovery unit 20. In addition, it is possible to mix and supply hot wastewater having different temperatures used in different places such as miscellaneous wastewater, pools, and baths, at a substantially constant temperature. This reduces the fluctuation of heat applied to the heat pump unit 30, reduces the load fluctuation in the heat pump unit 30, and enables an efficient and stable operation.

  The heat recovery unit 20 includes a heat exchange unit 21 shown in FIG. 2 and a heat storage unit 23 that stores hot water. The heat recovery unit 20 gives the heat of the circulating water heated by the heat exchange unit 21 to the hot water in the heat storage unit 23. The warm water in the heat storage unit 23 is sent to the heat pump unit 30, and the heat of the warm water is given to the heat medium. Therefore, the circulating water is circulated between the heat exchange unit 21 and the heat storage unit 23 by the circulation pump 24 which is a circulation means, and the hot water is circulated between the heat storage unit 23 and the heat pump unit 30 as a circulation means. Circulated by pump 25.

  The heat storage unit 23 can be configured in the same manner as the heat exchange unit 21 shown in FIG. 2. The raw water put in the heat storage unit 23 is warmed to warm water, the warm water is stored, and heat is given each time. It functions as an almost constant temperature heat storage source. The heat storage unit 23 sends internal hot water to the heat pump unit 30 by the circulation pump 25 to give the heat pump unit 30 constant heat.

  By providing the heat storage unit 23 in this way, the temperature fluctuation becomes very small, but the temperature of the hot water supplied to the heat pump unit 30 via the heat storage unit 23 is compared with the case where the circulating water is directly supplied. About 1-2 ° C. However, since the temperature fluctuation becomes very small, the heat fluctuation given to the heat pump unit 30 is also greatly reduced, and the operation of the heat pump unit 30 can be made more efficient and stable.

  The hot water tank 40 and the bathtub of the heat storage unit 23 can be made of a plastic resin such as FRP like the heat exchange unit 21. In the heat storage unit 23, both the bathtub and the tube are made of carbon steel. May be. The warm drainage tank 40 is preferably made of the above-mentioned plastic resin which is not easily corroded because the warm drainage contains soap, detergent, or other suspended matters.

  The hot wastewater is recovered by the heat recovery unit 20 and can be used for melting snow when the temperature is lowered and discharged. The drainage used for melting snow is sent to the septic tank 50 through a gutter etc., purified, and then sent to the public sewer.

  The septic tank 50 is composed of, for example, a solid-liquid separation device and a water treatment device having a plating tank, a contact plating tank, and a precipitation tank, an anaerobic filter bed tank, and a pretreatment device having a precipitation separation tank. And a water treatment device having a contact plating tank and a sedimentation tank.

  Up to now, the operation rate reduction system for an existing boiler according to the present invention has been described in detail with reference to the embodiments shown in the drawings, but the present invention is not limited to the above-described embodiments, and other embodiments are described. It can be modified within the range that can be conceived by those skilled in the art, such as addition, change, deletion, etc. is there.

DESCRIPTION OF SYMBOLS 1 ... Existing boiler, 2 ... Water supply line, 3 ... Hot water supply line, 4 ... Water supply pump, 10 ... Hot water storage tank, 20 ... Heat recovery unit, 21 ... Heat exchange unit, 21a ... Bathtub, 21b ... Tube, 22 ... Circulating water, DESCRIPTION OF SYMBOLS 23 ... Thermal storage unit, 24, 25 ... Circulation pump, 30 ... Heat pump unit, 31 ... Heat absorption means, 32 ... Compression means, 33 ... Heating means, 34 ... Expansion means, 40 ... Warm drainage tank, 41 ... Warm drainage pump, 50 ... septic tank

Claims (4)

A system that reduces the operating rate of existing boilers,
A hot water storage tank connected to a water supply line of the existing boiler and a hot water supply line for sending out hot water generated by heating, receiving water through the water supply line, and capable of supplying hot water through the hot water line;
A heat recovery unit that recovers the heat of the hot wastewater discharged from the facility;
A heat absorbing means for absorbing the heat recovered by the heat recovery unit and applying the heat to the heat medium; a compression means for compressing the heat medium; and the water received by the hot water storage tank by the compressed heat medium. A heat pump unit including heating means for generating and returning to the hot water storage tank, and expansion means for expanding the compressed heat medium and supplying the heat medium to the heat absorption means,
An operating rate reduction system for an existing boiler that supplies hot water from the hot water tank to the existing boiler and heats it to a predetermined temperature.   The heat recovery unit includes a heat exchange unit that supplies heat of the hot wastewater to circulating water, sends the circulating water to the heat pump unit, and supplies heat of the circulating water to the heat medium in the heat absorption means. The operation rate reduction system of the existing boiler as described in 1.   The heat recovery unit includes a heat exchange unit that supplies heat of the warm water to the circulating water, and a heat storage unit that stores the hot water, and the heat of the circulating water heated by the heat exchange unit is stored in the heat storage unit. The operation rate reduction system of the existing boiler according to claim 1, wherein the hot water in the heat storage unit is fed to the heat pump unit, and the heat absorption means gives the heat to the heat medium.   4. The apparatus according to claim 1, further comprising a warm drain tank that receives and stores the warm drainage discharged from the facility, and drainage means that supplies the stored warm drainage to the heat recovery unit. The operating rate reduction system of the existing boiler described in 1.