JP2011052942A - Exhaust heat-using system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust heat-using system recovering heat of waste water and effectively using the heat throughout the year. <P>SOLUTION: The exhaust heat-using system includes: a pump device 12 for pumping up waste water within a waste water treatment tank 11; an exhaust heat recovery heat exchanger 13 having a heat exchanger primary side 13a through which the waste water passes and a heat exchanger secondary side 13b for exchanging heat; an air conditioner 15 having a preheating heat exchanger 16 for preheating outside air and controlling the temperature and humidity of the outside air to supply the outside air to an indoor air conditioning zone 14; a cooling tower 17; a refrigerating machine 19 for cooling the air conditioner 15 or inside of a production facility side 18; a refrigerant circuit 21 for making refrigerant fluid made to pass through the heat exchanger secondary side 13b flow in the preheating heat exchanger 16, the cooling tower 17 and the refrigerating machine 19; and a preheating cooling route selector valve 35 arranged in the refrigerant circuit 21 and capable of switching a circulation route of the refrigerant fluid between a preheating route form for circulation in the heat exchanger secondary side 13b and the preheating heat exchanger 16 and a cooling route form for circulation in the heat exchanger secondary side 13b, the cooling tower 17 and the refrigerating machine 19. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an exhaust heat utilization system, and more particularly to an exhaust heat utilization system for performing air conditioning or the like by effectively using low-temperature factory effluent drained in, for example, a factory manufacturing process.

  Conventionally, for example, in a manufacturing process in a factory that manufactures foods and drinks, a large amount of raw materials, container washing water, and the like are generated. After the waste water treatment is performed, this washing water is poured into public sewage without using waste heat. Moreover, generally, the waste water from these factories is often about 20 to 25 ° C. throughout the year for the convenience of drainage facilities. On the other hand, the temperature of a heating source or a cold heat source required in an air conditioning facility or a production facility is usually 40 ° C. or higher for the heating source and 15 ° C. or lower for the cold heat source. It is a halfway temperature range that is difficult to use on both the cooling and cooling sides. For this reason, it is only a grade used as preheating or reheating, and many air-conditioning systems using exhaust heat for this preheating and reheating are known conventionally (for example, refer to patent documents 1).

Japanese Patent Application Laid-Open No. 2003-202165.

  As described above, the low temperature drainage around 25 ° C. generated in the manufacturing process of the conventional factory is difficult to efficiently recover the heat, and is therefore only used as preheating or reheating, and uses that heat. Applications were limited. In addition, it was difficult to use throughout the year, causing operational problems.

  Therefore, there is a technical problem to be solved in order to provide a waste heat utilization system that can recover the amount of heat held by the waste water with a simple system and can be used effectively throughout the year. Aims to solve this problem.

  The present invention has been proposed to achieve the above object, and the invention according to claim 1 is directed to a waste heat utilization system that recovers and uses the heat of low-temperature waste water discharged to a waste water treatment tank. A pump device that pumps up the waste water in the treatment tank; a heat exchanger primary side through which the waste water pumped up by the pump device passes; and a heat exchanger secondary side that performs heat exchange with the heat exchanger primary side. It has a heat exchanger for exhaust heat recovery and a preheat heat exchanger that preheats the outside air, and the temperature and humidity of the outside air adjusted by the preheat heat exchanger are adjusted and supplied to the indoor air conditioning zone An air conditioner that performs heat exchange with the outside air, a refrigerator that cools the air conditioner or the production apparatus, and a refrigerant fluid that passes through the secondary side of the heat exchanger and the heat exchanger for preheating and the cooling A refrigerant circuit that circulates through the tower and the refrigerator, and the refrigerant circuit A preheating path mode in which the refrigerant fluid circulates and circulates through the heat exchanger secondary side and the preheating heat exchanger, the heat exchanger secondary side, and the An exhaust heat utilization system comprising a cooling tower and a preheating / cooling path switching valve that can be switched to a cooling path mode that circulates via the refrigerator.

  According to this structure, the waste water temperature supplied to the heat exchanger primary side in the heat exchanger for exhaust heat recovery is, for example, 20 to 25 ° C. throughout the year, and the outside air temperature in winter is, for example, 17 ° C. or less. In such a case, the preheating / cooling path switching valve is operated so that the path through which the refrigerant fluid circulates and circulates in the refrigerant circuit is circulated via the heat exchanger secondary side and the preheating heat exchanger. When switching to, the heat of the waste water collected on the secondary side of the heat exchanger is sent to the preheating heat exchanger, and the outside air is warmed with the collected heat in the preheating heat exchanger. The outside air heated here is further adjusted to an appropriate temperature and humidity by an air conditioner, and then supplied to the indoor air conditioning zone. Therefore, by performing the pre-heat treatment for introducing the outside air in the winter season or the like, the load of the outside air heat treatment in the air conditioner is reduced.

  On the other hand, when the outside air temperature is, for example, 17 ° C. or more and the recovered heat cannot be effectively used as the outside air preheating in summer or the like, the preheating / cooling path switching valve is operated and the refrigerant fluid When the path through which the refrigerant circulates in the refrigerant circuit is switched to the cooling path mode side, the heat of the waste water collected on the secondary side of the heat exchanger is sent to the refrigerator through the cooling tower, and the refrigerator is cooled. Used as heat to do. As a result, the temperature of the cooling water in the summer in the refrigerator becomes lower than that in the past, and the heat treatment load in the refrigerator is reduced.

  According to a second aspect of the present invention, in the configuration according to the first aspect, in the refrigerant circuit, the refrigerant fluid heading from the heat exchanger secondary side to the cooling tower is bypassed in the middle, and the refrigerator and the heat A bypass path that circulates through the secondary side of the exchanger, a bypass path aspect in which the refrigerant fluid circulates from the cooling path aspect via the bypass path, and a switching from the bypass path aspect to the cooling path aspect can be switched. Provided is an exhaust heat utilization system provided with a bypass / cooling path switching valve.

  According to this configuration, when the outside air temperature is, for example, 17 ° C. or higher in summer and the like, but the refrigerant fluid cooled via the heat exchanger secondary side is not so high, for example, 32 ° C. or less, bypass / cooling is performed. By operating the path switching valve, the path through which the refrigerant fluid circulates and circulates in the refrigerant circuit is switched to the bypass cooling path mode, and the refrigerant fluid does not pass through the cooling tower but passes through the refrigerator and the heat exchanger secondary side. Thus, the refrigerator can be operated with the cooling tower stopped.

  Invention of Claim 3 is the structure of Claim 1 or 2, The said waste water treatment tank is equipped with the adjustment tank provided in an upstream, and the final neutralization tank which receives the waste_water | drain overflowed from this adjustment tank, The said The pump device provides an exhaust heat utilization system including a circulation pipe in which the waste water pumped up from the final neutralization tank returns to the final neutralization tank through the primary side of the heat exchanger.

  According to this configuration, the pump device pumps the waste water once purified in the adjustment tank from the final neutralization tank and returns it to the final neutralization tank again through the primary side of the heat exchanger. Dirt on the inside of the secondary side is reduced.

  According to a fourth aspect of the present invention, in the configuration of the third aspect, the circulation pipe is provided with a strainer for filtering the waste water pumped up from the waste water treatment tank on the upstream side of the heat exchanger primary side. An exhaust heat utilization system is provided.

  According to this configuration, the waste water pumped up by the pump device is filtered through the strainer and then sent to the primary side of the heat exchanger. Therefore, corrosion or clogging of the metal surface inside the primary side of the heat exchanger is performed. Etc. can be further reduced.

According to a fifth aspect of the present invention, in the configuration according to the fourth aspect, the circulation pipe has a cleaning means for cleaning the inside of the strainer by flowing the drainage from the opposite direction into the inside of the strainer. I will provide a.

  According to this configuration, when drainage is allowed to flow into the strainer from the opposite direction, dust or the like adhering to the filter of the strainer is conveniently peeled off, and the inside of the strainer can be cleaned cleanly.

  Since the invention according to claim 1 recovers the heat of the waste water and uses it as energy for pre-heat treatment for introducing outside air in winter, etc., and uses it as energy for cooling the cooling water of the refrigerator in summer, etc. Waste heat can be used through. That is, by performing the pre-heat treatment for introducing the outside air in winter or the like, the load of the outside air heat treatment in the air conditioner is reduced, and the energy consumption of the heating source device such as a boiler can be reduced. On the other hand, since the cooling water of the refrigerator can be cooled to a temperature lower than that in the past in summer or the like, the energy efficiency of the refrigerator is improved. Thereby, an energy saving effect can be obtained throughout the year.

  According to the second aspect of the invention, since the refrigerator can be operated in a state where the cooling tower is stopped according to the outside air temperature, in addition to the effect of the first aspect of the invention, further energy saving effect can be obtained. .

  According to the third aspect of the present invention, dirt on the inside of the heat exchanger primary side and the like can be reduced, so that in addition to the effect of the first aspect of the invention, the maintenance cost can be kept low.

  Since the invention according to claim 4 can be operated with less contamination of the inside of the heat exchanger primary side, etc., in addition to the effect of the invention according to claim 3, the number of maintenance is further reduced. Cost can be kept low.

  According to the fifth aspect of the present invention, since the inside of the strainer can be easily cleaned, in addition to the effect of the fourth aspect of the invention, the maintenance is further simplified and the cost can be kept low.

The conceptual diagram of the waste heat utilization system which concerns on this invention.

  In order to achieve the object of the present invention to provide a waste heat utilization system that can recover the amount of heat retained by waste water with a simple system and can be used effectively throughout the year, the waste water is discharged into a waste water treatment tank. In a waste heat utilization system that collects and uses heat of low-temperature wastewater, a pump device that pumps up the wastewater in the wastewater treatment tank, a heat exchanger primary side through which the wastewater pumped up by the pump device passes, and the heat An exhaust heat recovery heat exchanger having a heat exchanger secondary side that exchanges heat with the primary side of the exchanger, and a preheat heat exchanger that preheats the outside air, and the preheat heat exchanger An air conditioner that adjusts the temperature and humidity of the adjusted outside air and supplies it to the indoor air conditioning zone, a cooling tower that exchanges heat with the outside air, a refrigerator that cools the air conditioner or the production apparatus, and the heat exchange The refrigerant fluid passing through the secondary side A preheat heat exchanger, the cooling tower, a refrigerant circuit that is circulated through the refrigerator, and a path that is arranged in the refrigerant circuit and through which the refrigerant fluid circulates and passes through the heat exchanger secondary side and the preheater. A preheating / cooling path switching valve capable of switching between a preheating path mode circulating via a heat exchanger, a cooling path mode circulating via the heat exchanger secondary side, the cooling tower, and the refrigerator; Realized by having a configuration with

  Hereinafter, a preferred embodiment of the exhaust heat utilization system of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a conceptual diagram of an exhaust heat utilization system according to the present invention.

  In this figure, this waste heat utilization system includes, for example, a wastewater treatment tank 11 that receives wastewater discharged from a factory, a pump device 12 that pumps up wastewater in the wastewater treatment tank 11, and a wastewater that recovers heat of the wastewater. A heat recovery heat exchanger 13, an air conditioner 15 that takes in outside air, adjusts the temperature and humidity of the outside air, and supplies the air conditioning zone 14 to the indoor air conditioning zone 14; and preheats the outside air taken into the air conditioner 15. A preheating heat exchanger 16, a cooling tower 17, and a refrigerator 19 for cooling the air conditioner or production apparatus side 18 are provided. The heat exchanger 13 for exhaust heat recovery, the heat exchanger 16 for preheating, the cooling tower 17 and the refrigerator 19 are directly connected to each other through a refrigerant pipe 20, and the same air conditioning system circulating water (hereinafter referred to as the air conditioning system circulating water). , "Refrigerant fluid") is configured to flow through the refrigerant circuit 21.

  The waste water treatment tank 11 includes an adjustment tank 22 and a final neutralization tank 23 that are juxtaposed with each other. Waste water from the factory is introduced into the adjustment tank 22 for purification, and waste water overflowed in the adjustment tank 22 flows into the final neutralization tank 23. In addition, although the waste_water | drain temperature of the final neutralization tank 23 in a present Example is 20-25 degreeC throughout the year, for example, although the waste_water | drain purified in the adjustment tank 22 is colorless and transparent, usually organic substances, a silica, etc. There are a few fine suspended solids.

  The exhaust heat recovery heat exchanger 13 includes a heat exchanger primary side 13a through which the waste water flows and a heat exchanger secondary side 13b through which the refrigerant fluid of the refrigerant circuit 21 flows, and the heat exchanger primary side The heat of the waste water passing through the inside of 13a can be transmitted to the secondary side 13b of the heat exchanger to recover the heat of the waste water.

  The pump device 12 includes a pump 24, a strainer 25, and a circulation pipe 26. The circulation pipe 26 passes through the final neutralization tank 23 again through the pump 24, the strainer 25, and the heat exchanger primary side 13a of the heat exchanger 13 for exhaust heat recovery. It is arranged by a route returning to 23.

  The pump 24 is an inverter type electric pump, and is a pump for pumping the waste water in the final neutralization tank 23 and sending the pumped waste water to the exchanger primary side 13 a through the strainer 25.

  The strainer 25 is a device that filters out impurities contained in the waste water pumped up by the pump 24, and periodically performs a cleaning process and filter replacement.

  The pump device 12 includes cleaning pipes 27a and 27b as means for removing impurities accumulated in the heat exchanger primary side 13a of the exhaust heat recovery heat exchanger 13 and impurities accumulated in the strainer 25. 27c, 27d, and on-off valves 28a, 28b, 28c, 28d, 28e, 28f, 28g, 28h.

  During normal operation, the on-off valves 28a, 28c, 28d and 28f are opened, the on-off valves 28b, 28e, 28g and 28h are closed, and the pump 24 is driven. Thereby, the waste water in the final neutralization tank 23 pumped up by the pump 24 passes through the opening / closing valve 28a, the strainer 25, the opening / closing valves 28c, 28d, and from the upper part to the lower part of the heat exchanger primary side 13a. The heat flows through the primary side 13a of the heat exchanger, and then flows through a path returning to the final neutralization tank 23 through the on-off valve 28f.

  On the other hand, when the strainer 25 is washed, the on-off valves 28a and 28c are closed, the on-off valves 28b and 27h are opened, and the pump 24 is driven. Thereby, the waste water in the final neutralization tank 23 pumped up by the pump 24 passes through the opening / closing valve 28b, enters the strainer 25 from the lower part of the strainer 25, and then passes through the opening / closing valve 28h to the adjusting tank 22. It is carried on the return path. As a result, flushing cleaning is performed in the strainer 25 by flowing waste water from a direction opposite to that during normal operation, and simple cleaning can be performed. Note that the internal filter is replaced when the simple cleaning cannot cope.

  In addition, in the primary side 13a of the heat exchanger 13 for exhaust heat recovery to which waste water is supplied as a heat medium, fine floating substances in the waste water adhere to the inside, and corrosion of the metal surface and bacteria are generated. It is prone to breed and slam, causing clogging. As a result, energy saving effect due to insufficient flow rate and water leakage accident due to corrosion may occur. The inside of the primary side 13a can be periodically cleaned. When cleaning the inside of the heat exchanger primary side 13a, the on-off valves 28a, 28d, 28f, 28h are closed, the on-off valves 28b, 28c, 28e, 28g are opened, and the pump 24 is driven. As a result, the waste water in the final neutralization tank 23 pumped up by the pump 24 passes through the on-off valve 28b and the on-off valves 28c, 28e, and flows from the lower part to the upper part of the heat exchanger primary side 13a. It flows through the exchanger primary side 13a, and then flows through a path returning to the final neutralization tank 23 through the on-off valve 28g. Thereby, in the heat exchanger primary side 13a, contrary to the time of a normal driving | operation, waste_water | drain flows from the bottom toward the top, and washing | cleaning is performed. During cleaning, a chemical cleaning port may be installed in the piping system of the heat exchanger primary side 13a to perform acid / alkali cleaning.

  In addition, pressure sensors 29a, 29b, 29c, and 29d that detect the pressure in the circulation pipe 26 are disposed in the circulation pipe 26 of the pump device 12, and are detected by the pressure sensors 29a to 29d. A control circuit (not shown) drives and controls the pump 24 according to the pressure in the pipe.

  The air conditioner 15 includes a preheating heat exchanger 15a, a cooling heat exchanger 15b, a heating heat exchanger 15c, a humidifier 15d, and an air supply fan 15e. The air conditioner 15 is provided with a sensor 30 that detects the temperature and humidity of the air passing through the air conditioner 15.

  In the air conditioner 15, the outside air taken in by driving the air supply fan 15 e is heated to a predetermined temperature by the preheating heat exchanger 15 a and the heating heat exchanger 15 c during the heating / humidifying operation in winter. While being warmed, necessary humidity is added by the humidifier 15d, and thereafter, the air supply fan 15e is driven to send out to the indoor air conditioning zone 14. On the other hand, at the time of cooling / dehumidifying operation in summer, etc., after dehumidifying and cooling to a predetermined dew point temperature in the cooling heat exchanger 15c, the air supply fan 15e is driven and sent to the indoor air conditioning zone 14. Although not shown, the path of the heat transfer fluid to the preheating heat exchanger 15a, the cooling heat exchanger 15b, and the heating heat exchanger 15c is provided as a separate path independent of the refrigerant circuit 21. It has been.

  The preheating heat exchanger 16 is disposed on the front side of the air conditioner 15, and when the temperature of the outside air taken into the air conditioner 15 at the time of heating / humidifying operation in winter or the like is as low as 17 ° C. or less, for example, The heat recovered by the heat exchanger 13 for exhaust heat recovery is used to warm the outside air, and the exhaust air is supplied via the on-off valves 31a and 31b, the on-off valve 32 and the inverter-type pump 33 of the refrigerant circuit 21. The heat recovery heat exchanger 13 is connected to the heat exchanger secondary side 13b. A temperature sensor 34 for detecting the temperature of the outside air is provided on the outside air intake side of the preheating heat exchanger 16. The on-off valves 31a and 31b form a preheating / cooling path switching valve 35 together with the on-off valves 31c, 31d, and 31e that are also disposed in the refrigerant circuit 21.

  In the preheating heat exchanger 16, when the pump 33 is driven with the on-off valves 31a, 31b, 32 open, the refrigerant fluid in the refrigerant circuit 21 is transferred to the secondary side of the heat exchanger. 13b, the on-off valve 31a, the preheating heat exchanger 16, and the on-off valves 32 and 31b are sequentially passed through the path returning to the pump 33 to warm the outside air passing through the preheating heat exchanger 16 to a predetermined temperature. It can be done.

  The cooling tower 17 includes a cooling heat exchanger 17a, a water storage tank 17b, a pump 17c, a sprinkler 17d, and a blower fan 17e. The cooling heat exchanger 17a is a heat exchanger connected to the refrigerant circuit 21, and the refrigerant circuit 21 has a temperature sensor 39 that detects the temperature of the refrigerant fluid that has passed through the cooling heat exchanger 17a. Is provided. A signal from the temperature sensor 39 is supplied to a controller 17f that controls driving and stopping of the blower fan 17e.

  When the pump 17c is driven in the cooling tower 17, the water in the water storage tank 17b is pumped up to the sprinkler 17d, and water is sprinkled from the sprinkler 17d to the cooling heat exchanger 17a. The heat exchanger 17a is cooled, and the refrigerant fluid flowing through the cooling heat exchanger 17a is also cooled.

  In the refrigerant circuit 21, in addition to the preheating / cooling system path switching valve 35, a sensor 36 for detecting the temperature of the refrigerant fluid sent to the refrigerator 19, and a heat exchanger 13 for exhaust heat recovery from the refrigerator 19. A sensor 31 for detecting the temperature of the refrigerant fluid flowing through the refrigerant, and adjusting the flow rate of the refrigerant fluid flowing through the bypass passage 21a when the temperature of the refrigerant fluid sent to the refrigerator 19 becomes lower than a predetermined temperature. The refrigerant fluid flowing through the cooling heat exchanger 17a and the refrigerant fluid that flows in by bypassing the bypass passage 21 are mixed, and the temperature of the refrigerant fluid supplied to the refrigerator 19 is lower than a predetermined temperature. There are provided a three-way valve 37 as a bypass cooling system path switching valve that is controlled so as not to become a refrigerant, a refrigerant pump 38 that sends the refrigerant fluid in the refrigerant circuit 21 to the refrigerator 19, and the like. The three-way valve 37 is controlled by a controller (not shown).

  Next, the operation of the exhaust heat utilization system configured as described above will be described. In the following description, it is assumed that the drainage temperature collected on the secondary side of the heat exchanger is, for example, 20 to 25 ° C. throughout the year, and the exhaust heat temperature of the drainage when the outside air temperature is, for example, 17 ° C. or less in winter. Is used for preheating, and when the outside air temperature is 17 ° C. or higher in summer or the like, the exhaust heat temperature of the waste water is used for cooling. However, these temperatures can be freely changed according to the environment. Is.

(1) When the outside temperature is, for example, 17 ° C or lower in winter, etc .;
The preheating / cooling path switching valve 35 constituting the preheating / cooling path switching valve 35 is switched to the preheating path mode side in which the on / off valves 31a, 31b, 31e are opened and the on / off valves 31c, 31d are closed. In this preheating path mode, the refrigerant circuit 21 is separated into the air conditioner 15 side and the refrigerator 19 side by switching of the preheating / cooling path switching valve 35, and the refrigerant fluid flows independently on each side. On the air conditioning device 15 side, when the pump 33 on the refrigerant circuit 21 side and the pump 24 on the pump device 12 side are driven, the heat exchanger 13 for exhaust heat recovery performs heat exchange between the waste water and the refrigerant fluid. The refrigerant fluid is warmed to a predetermined temperature close to 20-25 ° C. The refrigerant fluid warmed here is sent to the preheating heat exchanger 16, heat exchanged with the outside air in the preheating heat exchanger 16, and the outside air is warmed to a predetermined temperature close to 20 to 25 ° C. It sends to the air conditioner 15 side. On the air conditioner 15 side, the temperature and humidity of the outside air sent from the preheating heat exchanger 16 side are further adjusted and sent to the indoor air conditioning zone 14 to perform air conditioning in the indoor air conditioning zone 14.

  On the other hand, in the cooling of the air conditioner or production device side 18 on the refrigerator 19 side, the heat recovered by the exhaust heat recovery heat exchanger 13 is not used, and the cooling heat exchanger 17a of the cooling tower 17 and the A refrigerant fluid circulating through the refrigerator 19 is used.

(2) When the outdoor temperature is, for example, 17 ° C or higher in summer, etc .;
The on / off valves 31a, 31b, 31e constituting the preheating / cooling path switching valve 35 are closed, and the on / off valves 31c, 31d are opened to switch to the cooling path mode. In this cooling path mode, the refrigerant circuit 21 is disconnected between the preheating heat exchanger 16 and the exhaust heat recovery heat exchanger 13 by switching the preheating / cooling path switching valve 35. The exhaust heat recovery heat exchanger 13 is connected to the refrigerator 19 side and the cooling tower 17 side. In addition, when the temperature of the sensor 31 that detects the temperature of the refrigerant fluid that flows through the heat exchanger 13 for exhaust heat recovery from the refrigerator 19 is higher than, for example, 32 ° C., the refrigerant fluid is changed by switching the three-way valve 37. It is circulated through the heat exchanger 13 for exhaust heat recovery, the cooling tower 17 and the refrigerator 19. On the other hand, when the temperature is lower than 32 ° C., the bypass passage 21 a is used, and the refrigerant fluid circulates through the heat exchanger 13 for exhaust heat recovery and the refrigerator 19 without passing through the cooling tower 17. Then, the operation of the cooling tower 17 is kept in a resting state.

  That is, when the temperature of the refrigerant fluid in the heat exchanger 13 for exhaust heat recovery is, for example, about 37 ° C., when the pump 33 on the refrigerant circuit 21 side and the pump 24 on the pump device 12 side are driven, In the exchanger 13, heat exchange between the waste water and the refrigerant fluid is performed, and the refrigerant fluid is cooled to a temperature of 32 ° C. or lower. The cooled refrigerant fluid is sent to the cooling tower 17, further cooled to about 30 ° C. in the cooling tower 17, and sent to the refrigerator 19 side. On the refrigerator 19 side, the air conditioning apparatus or the production apparatus side 18 is cooled by the refrigerant fluid sent from the cooling tower 17 side.

  On the other hand, when the temperature of the refrigerant fluid in the exhaust heat recovery heat exchanger 13 is about 32 ° C., for example, when the pump 33 on the refrigerant circuit 21 side and the pump 24 on the pump device 12 side are driven, the heat for exhaust heat recovery In the exchanger 13, heat exchange between the waste water and the refrigerant fluid is performed, and the refrigerant fluid is cooled to a temperature of 27 ° C. or lower. The cooled refrigerant fluid is sent to the refrigerator 19 side. On the refrigerator 19 side, the air conditioning apparatus or the production apparatus side 18 is cooled by the refrigerant fluid sent from the exhaust heat recovery heat exchanger 13 side.

  Next, on the air conditioner 15 side, the preheat heat exchanger 16 and the air conditioner 15 are driven according to the temperature of the refrigerant fluid, and the temperature and humidity of the outside air are adjusted and sent to the indoor air conditioning zone 14. Air conditioning in the indoor air conditioning zone 14 is performed.

  Therefore, in the exhaust heat utilization system of the present embodiment, the heat of the waste water is recovered and used as energy for pre-heat treatment for introducing outside air in winter and the like, and as energy for cooling the cooling water of the refrigerator 19 in summer and the like. Because it is used, exhaust heat can be used throughout the year. That is, by performing the pre-heat treatment for introducing the outside air in winter or the like, the load of the outside air heat treatment in the air conditioner 15 is reduced, and the energy consumption can be reduced. On the other hand, since the cooling water of the refrigerator 19 can be cooled to a temperature lower than the conventional temperature in summer or the like, the energy efficiency of the refrigerator 19 is improved. Thereby, an energy saving effect can be obtained throughout the year.

  It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

  Although this invention demonstrated the case where factory wastewater was used effectively, it is applicable also when utilizing the heat | fever of wastewater other than factory wastewater.

DESCRIPTION OF SYMBOLS 11 Waste water processing tank 12 Pump apparatus 13 Heat exchanger 13a for heat recovery 13a Heat exchanger primary side 13b Heat exchanger secondary side 14 Indoor air-conditioning zone 15 Air conditioner 15a Preheating heat exchanger 15b Cooling heat exchanger 15c Heat exchanger for heating 15d Humidifier 15e Heating fan 16 Preheat heat exchanger 17 Cooling tower 17a Cooling heat exchanger 17b Water storage tank 17c Pump 17d Sprinkler 17f Controller 18 Air conditioner or production equipment side 19 Refrigerator 20 Refrigerant Pipe 21 Refrigerant circuit 21a Bypass path 22 Adjustment tank 23 Final neutralization tank 24 Pump 25 Strainer 26 Circulation pipes 27a to 27d Cleaning pipes 28a to 28h Open / close valves 29a to 29d Pressure sensor 30 Sensors 31a to 31e Open / close valve 31 Sensor 32 Open / close Valve 33 Pump 34 Sensor 35 Preheating / cooling path switching valve 36 Sensor 37 Three The valve (bypass cooling system passage switching valve)
38 Refrigerant pump 39 Sensor

Claims (5)

In the waste heat utilization system that recovers and uses the heat of the low temperature wastewater discharged to the wastewater treatment tank,
A pump device for pumping up the waste water in the water treatment tank;
A heat exchanger for exhaust heat recovery having a heat exchanger primary side through which the waste water pumped up by the pump device passes and a heat exchanger secondary side for exchanging heat with the heat exchanger primary side;
A heat exchanger for preheating to preheat the outside air;
An air conditioner for adjusting the temperature and humidity of the outside air adjusted by the heat exchanger for preheating and supplying the indoor air conditioning zone;
A cooling tower for exchanging heat with the outside air,
A refrigerator for cooling an air conditioner or a production device;
A refrigerant circuit that causes the refrigerant fluid passing through the secondary side of the heat exchanger to flow through the preheating heat exchanger, the cooling tower, and the refrigerator;
A preheating path mode in which the refrigerant fluid is circulated and circulated through the heat exchanger secondary side and the heat exchanger for preheating and the heat exchanger secondary arranged in the refrigerant circuit. A preheating / cooling path switching valve that can be switched to a cooling path mode that circulates through the side, the cooling tower, and the refrigerator,
A waste heat utilization system comprising:   In the refrigerant circuit, the refrigerant fluid heading from the heat exchanger secondary side to the cooling tower is bypassed in the middle and circulated through the refrigerator and the heat exchanger secondary side, A bypass path mode in which the refrigerant fluid circulates from the cooling path mode via the bypass path and a bypass / cooling path switching valve that can be switched from the bypass path mode to the cooling path mode are provided. The exhaust heat utilization system according to claim 1.   The waste water treatment tank includes an adjustment tank provided on the upstream side and a final neutralization tank that receives waste water overflowed from the adjustment tank, and the pump device replaces the waste water pumped up from the final neutralization tank. The exhaust heat utilization system according to claim 1, further comprising a circulation pipe that returns to the final neutralization tank through the primary side of the vessel.   The exhaust heat according to claim 3, wherein the circulation pipe is provided with a strainer for filtering the waste water pumped up from the waste water treatment tank on the upstream side of the heat exchanger primary side. Usage system.   5. The exhaust heat utilization system according to claim 4, wherein the circulation pipe has a cleaning means for cleaning the inside of the strainer by flowing the waste water from the opposite direction into the strainer.

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