JP2016079894A

JP2016079894A - Heat recovery system

Info

Publication number: JP2016079894A
Application number: JP2014212164A
Authority: JP
Inventors: 弘矩安藤; Hironori Ando; 岡本　裕介; Yusuke Okamoto; 裕介岡本
Original assignee: Miura Co Ltd
Current assignee: Miura Co Ltd
Priority date: 2014-10-17
Filing date: 2014-10-17
Publication date: 2016-05-16

Abstract

PROBLEM TO BE SOLVED: To perform an effective heat recovery through a heat recovery system using a load/unload machine while preventing a bad influence against a water treatment installation for introduction of water for a heat recovery heat exchanger.SOLUTION: Heat recovery heat exchangers 6, 7 are installed at air passages 8, 9 extending from compressors 2, 3 to air coolers 4, 5 so as to heat exchange compressed air with water to make hot water. Air passages 8a, 9a extending from the compressors 2, 3 to the heat recovery heat exchangers 6, 7 and the air passages 8b, 9b extending from the heat recovery heat exchangers 6, 7 to the coolers 4, 5 are connected by bypass passages 12, 13. Whether the compressed air from the compressors 2, 3 is flowed to the heat recovery heat exchangers 6, 7 or flowed to the bypass passages 12, 13 can be changed over. The compressors 2, 3 can be applied as load*unload machines and the compressed air is not conducted to the heat recovery heat exchangers 6, 7 during a time in which the compressors 2, 3 are kept in unloaded state. However, water can be conducted to the heat recovery heat exchangers 6, 7.SELECTED DRAWING: Figure 1

Description

本発明は、オイルフリー式の空気圧縮機で生じた圧縮熱を回収できる熱回収システムに関するものである。 The present invention relates to a heat recovery system capable of recovering compression heat generated by an oil-free air compressor.

従来、下記特許文献１の図２に開示されるように、圧縮機（２）からエアクーラ（８）への空気路（１２）に熱回収用熱交換器（９）を設ける一方、この熱回収用熱交換器（９）をバイパス路（２５）でバイパス可能とした熱回収システムが知られている。熱回収用熱交換器（９）では、圧縮空気と通水とを熱交換して、圧縮空気を冷却する一方、通水を加温できる。これにより、圧縮機（２）で生じた圧縮熱を、熱回収用熱交換器（９）において、給水タンク（５）への給水の加温に用いて、熱回収を図ることができる。 Conventionally, as disclosed in FIG. 2 of Patent Document 1 below, a heat recovery heat exchanger (9) is provided in an air passage (12) from the compressor (2) to the air cooler (8), while this heat recovery is performed. There is known a heat recovery system in which the heat exchanger (9) for use can be bypassed by a bypass passage (25). In the heat recovery heat exchanger (9), the compressed air and the water flow can be heat-exchanged to cool the compressed air, while the water flow can be heated. Thus, heat recovery can be achieved by using the compression heat generated in the compressor (2) in the heat recovery heat exchanger (9) for heating the water supplied to the water supply tank (5).

特開２０１２−８７６６４号公報JP 2012-87664 A

上述の熱回収システムは、熱回収用熱交換器において圧縮空気と通水とを熱交換して温水を製造することで、圧縮機からの熱回収を図るのが目的である。そのため、圧縮機の停止中、つまり圧縮空気が製造されない間は、熱回収用熱交換器への通水を停止する。また、同様の理由で、圧縮機がロード・アンロード機の場合、アンロード中には圧縮空気は製造されないから、熱回収用熱交換器へ通水する必要はない。 The above-described heat recovery system is intended to recover heat from the compressor by producing hot water by exchanging heat between compressed air and water in a heat recovery heat exchanger. Therefore, while the compressor is stopped, that is, while compressed air is not manufactured, water flow to the heat recovery heat exchanger is stopped. For the same reason, when the compressor is a load / unload machine, compressed air is not produced during unloading, so there is no need to pass water to the heat recovery heat exchanger.

しかしながら、ロードとアンロードとの切替えは、比較的頻繁（たとえば３０秒程度ごと）に起こり得るため、その度に通水の有無を切り替えたのでは、熱回収用熱交換器への給水路に設けた給水ポンプの発停が頻繁になるなど、水処理設備に悪影響を及ぼすおそれがある。 However, switching between loading and unloading can occur relatively frequently (for example, about every 30 seconds). Therefore, if the presence or absence of water flow is switched each time, the water supply path to the heat recovery heat exchanger is changed. There is a risk of adversely affecting water treatment facilities, such as frequent start and stop of the provided water pump.

そこで、本発明が解決しようとする課題は、ロード・アンロード機を用いた熱回収システムにおいて、熱回収用熱交換器の通水側の水処理設備への悪影響を防止しつつ、有効に熱回収を図ることにある。 Therefore, the problem to be solved by the present invention is that in a heat recovery system using a load / unload machine, the heat recovery heat exchanger is effectively heated while preventing adverse effects on the water treatment facility on the water flow side. The goal is to collect.

本発明は、前記課題を解決するためになされたもので、請求項１に記載の発明は、オイルフリー式の圧縮機からの圧縮空気を、冷却塔との間の循環水で冷却するか、ファンによる通風で冷却するエアクーラと、前記圧縮機から前記エアクーラへの空気路に設けられ、圧縮空気と水とを熱交換して温水を製造する熱回収用熱交換器と、前記圧縮機から前記熱回収用熱交換器への空気路と、前記熱回収用熱交換器から前記エアクーラへの空気路とを接続するバイパス路とを備え、前記圧縮機からの圧縮空気を前記バイパス路に通さずに前記熱回収用熱交換器を介して前記エアクーラへ送る熱回収可能状態と、前記圧縮機からの圧縮空気を前記熱回収用熱交換器に通さずに前記バイパス路を介して前記エアクーラへ送る熱回収停止状態とを切り替え可能とされ、前記圧縮機は、ロード・アンロード機とされ、前記圧縮機がアンロード中、前記熱回収用熱交換器への圧縮空気の流通はないが、前記熱回収用熱交換器に通水可能とされたことを特徴とする熱回収システムである。 The present invention has been made in order to solve the above-mentioned problems, and the invention according to claim 1 is a method in which compressed air from an oil-free compressor is cooled with circulating water between a cooling tower and An air cooler that is cooled by ventilation with a fan, a heat recovery heat exchanger that is provided in an air path from the compressor to the air cooler and that heat-exchanges compressed air and water to produce hot water, and from the compressor An air path to the heat recovery heat exchanger and a bypass path connecting the air path from the heat recovery heat exchanger to the air cooler are provided, and compressed air from the compressor is not passed through the bypass path. The heat recoverable state to be sent to the air cooler via the heat recovery heat exchanger and the compressed air from the compressor to the air cooler via the bypass without passing through the heat recovery heat exchanger Switch between heat recovery stop state The compressor is a load / unload machine, and while the compressor is unloaded, there is no flow of compressed air to the heat recovery heat exchanger, but the heat recovery heat exchanger It is a heat recovery system characterized by being able to pass water.

請求項１に記載の発明によれば、圧縮機がアンロード中、熱回収用熱交換器への圧縮空気の流通はないが、敢えて熱回収用熱交換器に通水し続けることが可能であるから、ロードとアンロードとが切り替えられる度に、熱回収用熱交換器への通水の有無が切り替えらえるのを防止することができる。これにより、熱回収用熱交換器への通水用の給水ポンプの頻繁な発停を抑えるなど、水処理設備の保護を図ることができる。 According to the first aspect of the present invention, while the compressor is unloaded, there is no flow of compressed air to the heat recovery heat exchanger, but it is possible to continue to flow through the heat recovery heat exchanger. Therefore, it is possible to prevent the presence or absence of water flow to the heat recovery heat exchanger from being switched each time the load and the unload are switched. Thereby, protection of water treatment equipment, such as suppressing frequent start and stop of the water supply pump for water flow to the heat exchanger for heat recovery, can be aimed at.

請求項２に記載の発明は、前記圧縮機がロード中、前記熱回収用熱交換器への通水条件を満たすと、前記熱回収可能状態にすると共に前記熱回収用熱交換器に通水する一方、前記熱回収用熱交換器への通水条件を満たさないと、前記熱回収停止状態にすると共に前記熱回収用熱交換器への通水を停止し、前記熱回収用熱交換器への通水中に、前記圧縮機がロードからアンロードへ切り替わった際には、前記熱回収用熱交換器への通水条件を満たす限り、前記熱回収用熱交換器への通水を継続し、前記熱回収用熱交換器への通水停止中に、前記圧縮機がロードからアンロードへ切り替わった際には、前記熱回収用熱交換器への通水停止を継続することを特徴とする請求項１に記載の熱回収システムである。 According to the second aspect of the present invention, when the compressor satisfies the water flow condition to the heat recovery heat exchanger while the compressor is being loaded, the heat recovery state is enabled and water is passed to the heat recovery heat exchanger. On the other hand, if the water flow condition to the heat recovery heat exchanger is not satisfied, the heat recovery is stopped and the water flow to the heat recovery heat exchanger is stopped and the heat recovery heat exchanger is stopped. When the compressor is switched from loading to unloading during water flow, water flow to the heat recovery heat exchanger is continued as long as the water flow condition to the heat recovery heat exchanger is satisfied. When the compressor is switched from loading to unloading while the water flow to the heat recovery heat exchanger is stopped, the water flow stop to the heat recovery heat exchanger is continued. The heat recovery system according to claim 1.

請求項２に記載の発明によれば、熱回収用熱交換器への通水中に、圧縮機がロードからアンロードへ切り替わった際には、熱回収用熱交換器への通水条件を満たす限り、熱回収用熱交換器への通水を継続する一方、熱回収用熱交換器への通水停止中に、圧縮機がロードからアンロードへ切り替わった際には、熱回収用熱交換器への通水停止を継続することで、ロードとアンロードとが切り替えられる度に、熱回収用熱交換器への通水の有無が切り替えらえるのを防止することができる。これにより、熱回収用熱交換器への通水用の給水ポンプの頻繁な発停を抑えるなど、水処理設備の保護を図ることができる。 According to the second aspect of the present invention, when the compressor is switched from loading to unloading during water flow to the heat recovery heat exchanger, the water flow condition to the heat recovery heat exchanger is satisfied. As long as the water flow to the heat recovery heat exchanger continues, if the compressor is switched from load to unload while the flow to the heat recovery heat exchanger is stopped, heat exchange for heat recovery By continuing the stoppage of water flow to the vessel, it is possible to prevent the presence or absence of water flow to the heat exchanger for heat recovery from being switched each time the load and the unload are switched. Thereby, protection of water treatment equipment, such as suppressing frequent start and stop of the water supply pump for water flow to the heat exchanger for heat recovery, can be aimed at.

請求項３に記載の発明は、前記熱回収用熱交換器へ通水しつつ前記圧縮機のアンロード時間が設定時間を超えると、前記熱回収用熱交換器への通水を停止することを特徴とする請求項１または請求項２に記載の熱回収システムである。 The invention according to claim 3 stops water flow to the heat recovery heat exchanger when the unload time of the compressor exceeds a set time while passing water to the heat recovery heat exchanger. The heat recovery system according to claim 1, wherein the heat recovery system is a heat recovery system.

請求項３に記載の発明によれば、熱回収用熱交換器へ通水しつつ圧縮機のアンロード時間が設定時間を超えることを条件に、熱回収用熱交換器への通水を停止するので、熱回収用熱交換器への通水の有無が頻繁に切り替えらえるのを防止することができる。また、アンロード時の加温の少ない給水を抑制することができる。 According to the third aspect of the present invention, water flow to the heat recovery heat exchanger is stopped on condition that the unload time of the compressor exceeds the set time while water is passed to the heat recovery heat exchanger. Therefore, it is possible to prevent frequent switching of the presence or absence of water flow to the heat recovery heat exchanger. Moreover, the water supply with little heating at the time of unloading can be suppressed.

請求項４に記載の発明は、前記熱回収用熱交換器への通水流量は、前記圧縮機がロード時の第一設定流量と、前記圧縮機がアンロード時の第二設定流量との二段階で切り替えられ、前記第二設定流量は、前記第一設定流量よりも少ない流量であることを特徴とする請求項１〜３のいずれか１項に記載の熱回収システムである。 According to a fourth aspect of the present invention, the flow rate of water to the heat recovery heat exchanger is a first set flow rate when the compressor is loaded and a second set flow rate when the compressor is unloaded. 4. The heat recovery system according to claim 1, wherein the heat recovery system is switched in two stages, and the second set flow rate is lower than the first set flow rate.

請求項４に記載の発明によれば、熱回収用熱交換器への通水流量を二段階で簡易に制御できる。また、アンロード時の通水流量をロード時の通水流量よりも制限することで、アンロード時の加温の少ない給水を抑制することができる。 According to invention of Claim 4, the flow volume of the water flow to the heat exchanger for heat recovery can be easily controlled in two steps. Further, by limiting the water flow rate at the time of unloading compared to the water flow rate at the time of loading, water supply with less heating at the time of unloading can be suppressed.

請求項５に記載の発明は、前記熱回収用熱交換器への給水路には、第一電磁弁を備えた第一給水路と、第二電磁弁を備えた第二給水路とが並列に設けられ、前記第二給水路は、前記第一給水路よりも管径が小さく形成されており、前記熱回収用熱交換器への通水時、前記圧縮機がロード中なら前記第一電磁弁と前記第二電磁弁との双方を開くか前記第一電磁弁を開き、前記圧縮機がアンロード中なら前記第二電磁弁を開くことを特徴とする請求項４に記載の熱回収システムである。 According to the fifth aspect of the present invention, in the water supply path to the heat recovery heat exchanger, a first water supply path having a first electromagnetic valve and a second water supply path having a second electromagnetic valve are arranged in parallel. The second water supply passage is formed with a pipe diameter smaller than that of the first water supply passage, and when the compressor is being loaded at the time of water flow to the heat recovery heat exchanger, the first water supply passage 5. The heat recovery according to claim 4, wherein both the solenoid valve and the second solenoid valve are opened or the first solenoid valve is opened, and the second solenoid valve is opened when the compressor is unloaded. System.

請求項５に記載の発明によれば、ロード時の第一設定流量と、アンロード時の第二設定流量との二段階の流量調整を、電動弁（モータバルブ）を用いることなく、電磁弁を用いて、簡易な構成で安価に実現することができる。 According to the invention described in claim 5, the two-stage flow rate adjustment of the first set flow rate during loading and the second set flow rate during unloading can be performed without using an electric valve (motor valve). Can be realized at low cost with a simple configuration.

さらに、請求項６に記載の発明は、前記圧縮機として、低段圧縮機と高段圧縮機とを備え、前記エアクーラとして、インタークーラとアフタークーラとを備え、前記熱回収用熱交換器として、第一熱回収用熱交換器と第二熱回収用熱交換器とを備え、前記低段圧縮機からの圧縮空気は、前記インタークーラを介して前記高段圧縮機へ送られ、前記高段圧縮機においてさらに圧縮された後、前記アフタークーラへ送られ、前記低段圧縮機から前記インタークーラへの空気路に、前記第一熱回収用熱交換器が設けられる一方、前記高段圧縮機から前記アフタークーラへの空気路に、前記第二熱回収用熱交換器が設けられ、前記第一熱回収用熱交換器と前記第二熱回収用熱交換器とには、設定順序で直列に水が通されるか、並列に水が通され、前記各熱回収用熱交換器について、前記バイパス路を設けたことを特徴とする請求項１〜５のいずれか１項に記載の熱回収システムである。 Furthermore, the invention described in claim 6 includes a low-stage compressor and a high-stage compressor as the compressor, an intercooler and an aftercooler as the air cooler, and the heat recovery heat exchanger. A first heat recovery heat exchanger and a second heat recovery heat exchanger, compressed air from the low stage compressor is sent to the high stage compressor through the intercooler, After further compression in the stage compressor, the first stage heat recovery heat exchanger is provided in the air path from the low stage compressor to the intercooler, and sent to the after cooler, while the high stage compression The second heat recovery heat exchanger is provided in the air path from the machine to the aftercooler, and the first heat recovery heat exchanger and the second heat recovery heat exchanger are arranged in a set order. Water is passed in series or water is passed in parallel, For the heat-recovery heat exchanger, a heat recovery system according to any one of claims 1 to 5, characterized by providing the bypass passage.

請求項６に記載の発明によれば、二段のオイルフリー式圧縮機の各段の圧縮機について、上述した各請求項に記載の発明を適用することができる。 According to the invention described in claim 6, the invention described in each of the above-described claims can be applied to the compressor of each stage of the two-stage oil-free compressor.

本発明によれば、ロード・アンロード機を用いた熱回収システムにおいて、熱回収用熱交換器の通水側の水処理設備への悪影響を防止しつつ、有効に熱回収を図ることができる。 According to the present invention, in a heat recovery system using a load / unload machine, it is possible to effectively recover heat while preventing adverse effects on the water treatment facility on the water flow side of the heat exchanger for heat recovery. .

本発明の熱回収システムの実施例１を示す概略図である。It is the schematic which shows Example 1 of the heat recovery system of this invention. 本発明の熱回収システムの実施例２を示す概略図である。It is the schematic which shows Example 2 of the heat recovery system of this invention.

以下、本発明の具体的実施例を図面に基づいて詳細に説明する。 Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

図１は、本発明の熱回収システム１の実施例１を示す概略図である。 FIG. 1 is a schematic diagram showing Example 1 of the heat recovery system 1 of the present invention.

本実施例の熱回収システム１は、二段のオイルフリー式の空気圧縮機に適用される。この場合、圧縮機として、低段圧縮機２と高段圧縮機３とを備え、各圧縮機２，３からの圧縮空気を冷却するエアクーラとして、インタークーラ４とアフタークーラ５とを備える。低段圧縮機２からの圧縮空気は、インタークーラ４を介して高段圧縮機３へ送られ、高段圧縮機３においてさらに圧縮された後、アフタークーラ５へ送られる。アフタークーラ５を通過後の圧縮空気は、所望によりエアドライヤやエアタンクを介して、各種の圧縮空気利用機器へ送られる。 The heat recovery system 1 of this embodiment is applied to a two-stage oil-free air compressor. In this case, a low-stage compressor 2 and a high-stage compressor 3 are provided as compressors, and an intercooler 4 and an aftercooler 5 are provided as air coolers for cooling the compressed air from the compressors 2 and 3. The compressed air from the low stage compressor 2 is sent to the high stage compressor 3 via the intercooler 4, further compressed in the high stage compressor 3, and then sent to the after cooler 5. The compressed air after passing through the aftercooler 5 is sent to various types of equipment using compressed air via an air dryer or an air tank as required.

低段圧縮機２および高段圧縮機３は、典型的には、モータにより駆動されると共にギアにより連動して発停される。低段圧縮機２は、外気を吸入し圧縮して吐出し、高段圧縮機３は、低段圧縮機２からインタークーラ４を介した圧縮空気をさらに圧縮して吐出する。 The low stage compressor 2 and the high stage compressor 3 are typically driven by a motor and started and stopped in conjunction with a gear. The low stage compressor 2 sucks outside air, compresses and discharges it, and the high stage compressor 3 further compresses and discharges compressed air from the low stage compressor 2 via the intercooler 4.

圧縮機２，３は、本実施例ではロード・アンロード機とされる。この場合、圧縮機２，３は、ロード、アンロードおよび停止の三位置で制御される。ロード中、圧縮機２，３は圧縮空気を製造し、アンロード中、圧縮機２，３は圧縮空気を製造しない。たとえば、本実施例では、低段圧縮機２の吸込口に弁を備え、ロード中、この弁を開く一方、アンロード中、この弁を閉じる。また、アンロード中、高段圧縮機３の吐出側を、大気圧下へ開放する。 The compressors 2 and 3 are load / unload machines in this embodiment. In this case, the compressors 2 and 3 are controlled at three positions: loading, unloading and stopping. During loading, the compressors 2 and 3 produce compressed air, and during unloading, the compressors 2 and 3 do not produce compressed air. For example, in the present embodiment, a valve is provided at the suction port of the low-stage compressor 2, and the valve is opened during loading, while the valve is closed during unloading. Further, during unloading, the discharge side of the high stage compressor 3 is opened to atmospheric pressure.

インタークーラ４およびアフタークーラ５は、それぞれ、圧縮空気と冷却水とを混ぜることなく熱交換する間接熱交換器である。そのために、インタークーラ４およびアフタークーラ５の冷却水路４ａ，５ａには、冷却塔（クーリングタワー）との間で冷却水が循環される。この際、冷却塔からの冷却水は、インタークーラ４に通された後にアフタークーラ５に通されてもよいし、これとは逆に、アフタークーラ５に通された後にインタークーラ４に通されてもよい。あるいは、冷却塔からの冷却水は、インタークーラ４とアフタークーラ５とに並列に通されてもよい。 The intercooler 4 and the aftercooler 5 are indirect heat exchangers that exchange heat without mixing compressed air and cooling water, respectively. Therefore, cooling water is circulated between the cooling water passages 4a and 5a of the intercooler 4 and the aftercooler 5 with the cooling tower (cooling tower). At this time, the cooling water from the cooling tower may be passed through the intercooler 4 and then through the aftercooler 5. Conversely, after passing through the aftercooler 5, the cooling water is passed through the intercooler 4. May be. Alternatively, the cooling water from the cooling tower may be passed through the intercooler 4 and the aftercooler 5 in parallel.

このような二段のオイルフリー式の空気圧縮機において、本実施例の熱回収システム１は、各段の圧縮機２（３）からの圧縮空気をエアクーラ４（５）に通す前に熱回収用熱交換器６（７）に通して、圧縮熱を回収可能に構成される。具体的には、本実施例の熱回収システム１は、各段の圧縮機２，３で生じた圧縮熱を熱回収用熱交換器６，７において通水の加温に用いて、圧縮熱を回収する。熱回収用熱交換器として、第一熱回収用熱交換器６と第二熱回収用熱交換器７とを備える。第一熱回収用熱交換器６は、低段圧縮機２からインタークーラ４への第一空気路８に設けられ、第二熱回収用熱交換器７は、高段圧縮機３からアフタークーラ５への第二空気路９に設けられる。 In such a two-stage oil-free air compressor, the heat recovery system 1 of the present embodiment recovers heat before passing the compressed air from the compressor 2 (3) of each stage through the air cooler 4 (5). It is configured to be able to recover the compression heat through the heat exchanger for heat 6 (7). Specifically, the heat recovery system 1 of the present embodiment uses the compression heat generated in the compressors 2 and 3 at each stage to heat the water in the heat recovery heat exchangers 6 and 7, thereby compressing heat. Recover. As the heat recovery heat exchanger, a first heat recovery heat exchanger 6 and a second heat recovery heat exchanger 7 are provided. The first heat recovery heat exchanger 6 is provided in the first air passage 8 from the low stage compressor 2 to the intercooler 4, and the second heat recovery heat exchanger 7 is supplied from the high stage compressor 3 to the aftercooler. In the second air passage 9 to 5.

第一熱回収用熱交換器６および第二熱回収用熱交換器７は、それぞれ、圧縮空気と水とを混ぜることなく熱交換する間接熱交換器である。そのために、第一熱回収用熱交換器６および第二熱回収用熱交換器７の通水路には、給水源（たとえば軟水器）から給水タンク１０への給水が、給水路１１を介して通される。この際、給水源からの水は、図示例のように、第二熱回収用熱交換器７に通された後に第一熱回収用熱交換器６に通されてもよいし、これとは逆に、第一熱回収用熱交換器６に通された後に第二熱回収用熱交換器７に通されてもよい。あるいは、給水源からの水は、第一熱回収用熱交換器６と第二熱回収用熱交換器７とに並列に通されてもよい。いずれにしても、各熱回収用熱交換器６，７において、圧縮空気と水とを熱交換して、圧縮空気を水で冷却できる一方、水を圧縮空気で加温できる。なお、給水タンク１０内の貯留水は、その用途を特に問わないが、たとえばボイラへの給水として用いられる。 The first heat recovery heat exchanger 6 and the second heat recovery heat exchanger 7 are indirect heat exchangers that exchange heat without mixing compressed air and water, respectively. Therefore, in the water passages of the first heat recovery heat exchanger 6 and the second heat recovery heat exchanger 7, water is supplied from a water supply source (for example, a water softener) to the water supply tank 10 via the water supply path 11. Passed. At this time, the water from the water supply source may be passed through the second heat recovery heat exchanger 7 and then through the first heat recovery heat exchanger 6 as shown in the illustrated example. Conversely, after passing through the first heat recovery heat exchanger 6, it may be passed through the second heat recovery heat exchanger 7. Alternatively, the water from the water supply source may be passed through the first heat recovery heat exchanger 6 and the second heat recovery heat exchanger 7 in parallel. In any case, in each of the heat recovery heat exchangers 6 and 7, the compressed air and water can be heat-exchanged to cool the compressed air with water, while the water can be heated with the compressed air. In addition, although the use in particular is not ask | required, the stored water in the water supply tank 10 is used, for example as water supply to a boiler.

各熱回収用熱交換器６，７について、圧縮空気の入口側と出口側とが、バイパス路１２，１３で接続される。具体的には、低段圧縮機２から第一熱回収用熱交換器６への第一熱交入口側空気路８ａと、第一熱回収用熱交換器６からインタークーラ４への第一熱交出口側空気路８ｂとが、第一バイパス路１２で接続される。同様に、高段圧縮機３から第二熱回収用熱交換器７への第二熱交入口側空気路９ａと、第二熱回収用熱交換器７からアフタークーラ５への第二熱交出口側空気路９ｂとが、第二バイパス路１３で接続される。 About each heat recovery heat exchanger 6 and 7, the inlet side and outlet side of compressed air are connected by bypass paths 12 and 13. Specifically, the first heat exchange inlet-side air passage 8a from the low stage compressor 2 to the first heat recovery heat exchanger 6 and the first heat exchanger 6 to the intercooler 4 from the first heat recovery heat exchanger 6 The heat exchange outlet side air passage 8 b is connected by the first bypass passage 12. Similarly, the second heat exchange inlet-side air passage 9a from the high stage compressor 3 to the second heat recovery heat exchanger 7 and the second heat exchange from the second heat recovery heat exchanger 7 to the aftercooler 5 are used. The outlet side air passage 9 b is connected by the second bypass passage 13.

各バイパス路１２，１３には、バイパス弁１４，１５が設けられる。具体的には、第一バイパス路１２には、第一バイパス弁１４が設けられる一方、第二バイパス路１３には、第二バイパス弁１５が設けられる。 In each bypass passage 12, 13, bypass valves 14, 15 are provided. Specifically, the first bypass passage 12 is provided with a first bypass valve 14, while the second bypass passage 13 is provided with a second bypass valve 15.

また、本実施例では、各熱回収用熱交換器６，７について、バイパス路１２，１３との分岐部よりも下流の熱交入口側空気路８ａ，９ａに、熱交入口側遮断弁１６，１７が設けられる一方、バイパス路１２，１３との合流部よりも上流の熱交出口側空気路８ｂ，９ｂに、熱交出口側遮断弁１８，１９が設けられる。具体的には、第一バイパス路１２との分岐部よりも下流の第一熱交入口側空気路８ａに、第一熱交入口側遮断弁１６が設けられる一方、第一バイパス路１２との合流部よりも上流の第一熱交出口側空気路８ｂに、第一熱交出口側遮断弁１８が設けられる。また、第二バイパス路１３との分岐部よりも下流の第二熱交入口側空気路９ａに、第二熱交入口側遮断弁１７が設けられる一方、第二バイパス路１３との合流部よりも上流の第二熱交出口側空気路９ｂに、第二熱交出口側遮断弁１９が設けられる。但し、詳細は後述するが、熱交入口側遮断弁１６，１７と熱交出口側遮断弁１８，１９との内、一方の設置を省略してもよい。 In the present embodiment, the heat recovery side heat exchangers 6, 7 are connected to the heat input side shut-off valves 16 in the heat input side air paths 8 a, 9 a downstream from the branch portions with the bypass paths 12, 13. , 17 are provided, and heat exchange outlet side shut-off valves 18, 19 are provided in the heat exchange outlet side air paths 8b, 9b upstream from the junction with the bypass paths 12, 13. Specifically, the first heat exchange inlet side shut-off valve 16 is provided in the first heat exchange inlet side air passage 8a downstream from the branch portion with the first bypass passage 12, while A first heat exchange outlet side shut-off valve 18 is provided in the first heat exchange outlet side air passage 8b upstream of the junction. In addition, the second heat exchange inlet side shut-off valve 17 is provided in the second heat exchange inlet side air passage 9a downstream from the branching portion with the second bypass passage 13, while the second heat exchange inlet side cutoff valve 17 is provided from the junction with the second bypass passage 13. The second heat exchange outlet side shut-off valve 19 is provided in the upstream second heat exchange outlet side air passage 9b. However, although details will be described later, installation of one of the heat exchange inlet side shutoff valves 16 and 17 and the heat exchange outlet side shutoff valves 18 and 19 may be omitted.

給水路１１を介した給水タンク１０への給水の有無または流量は、変更可能である。本実施例では、給水路１１には、各熱回収用熱交換器６，７よりも上流に、給水ポンプ２０および給水弁２１が設けられている。給水弁２１の開閉を切り替えることで、各熱回収用熱交換器６，７への通水の有無、ひいては給水タンク１０への給水の有無を切り替えることができる。また、給水弁２１の開度を調整することで、各熱回収用熱交換器６，７への通水流量、ひいては給水タンク１０への給水流量を調整することができる。なお、本実施例では、給水弁２１の開閉に連動して、給水ポンプ２０の発停がオンオフ制御される。つまり、給水弁２１の開放時、給水ポンプ２０を作動させ、給水弁２１の全閉時、給水ポンプ２０を停止させる。 The presence or the flow rate of water supplied to the water supply tank 10 via the water supply channel 11 can be changed. In the present embodiment, the water supply channel 11 is provided with a water supply pump 20 and a water supply valve 21 upstream of the heat recovery heat exchangers 6 and 7. By switching the opening / closing of the water supply valve 21, it is possible to switch the presence / absence of water flow to each heat recovery heat exchanger 6, 7, and consequently the presence / absence of water supply to the water supply tank 10. Further, by adjusting the opening degree of the water supply valve 21, the flow rate of water to each heat recovery heat exchanger 6, 7, and hence the water supply flow rate to the water supply tank 10 can be adjusted. In this embodiment, the on / off control of the water supply pump 20 is controlled on and off in conjunction with the opening and closing of the water supply valve 21. That is, when the water supply valve 21 is opened, the water supply pump 20 is operated, and when the water supply valve 21 is fully closed, the water supply pump 20 is stopped.

ところで、高段圧縮機３から圧縮空気が供給されるエアタンク（場合により管路でもよい）に圧力センサ（図示省略）を設けることで、圧縮空気の使用負荷を監視することができる。一方、給水タンク１０に水位センサ２２を設けることで、給水タンク１０内の温水の使用負荷を監視することができる。 By the way, the use load of compressed air can be monitored by providing a pressure sensor (not shown) in an air tank (which may be a pipe line in some cases) to which compressed air is supplied from the high stage compressor 3. On the other hand, the use load of the hot water in the water supply tank 10 can be monitored by providing the water level sensor 22 in the water supply tank 10.

また、所望により、次のようなセンサを設けてもよい。すなわち、給水タンク１０への給水路１１の内、各熱回収用熱交換器６，７よりも下流に温度センサ（図示省略）を設けることで、給水タンク１０への給水温度を監視することができる。さらに、給水路１１に流量計（図示省略）を設けることで、各熱回収用熱交換器６，７への通水流量、ひいては給水タンク１０への給水流量を監視することができる。 Further, if desired, the following sensor may be provided. That is, by providing a temperature sensor (not shown) downstream of the heat recovery heat exchangers 6 and 7 in the water supply path 11 to the water supply tank 10, the temperature of the water supply to the water supply tank 10 can be monitored. it can. Furthermore, by providing a flow meter (not shown) in the water supply path 11, it is possible to monitor the water flow rate to each heat recovery heat exchanger 6, 7, and consequently the water supply flow rate to the water supply tank 10.

次に、本実施例の熱回収システム１の制御について説明する。以下に述べる一連の制御は、図示しない制御器により実行される。つまり、制御器は、圧縮機（より具体的にはそのモータ）２，３、バイパス弁１４，１５、各遮断弁１６〜１９、給水ポンプ２０、給水弁２１の他、前述した圧力センサおよび水位センサ２２などに接続されており、各センサの検出信号などに基づき圧縮機２，３および各弁１４〜１９，２１などを制御する。 Next, control of the heat recovery system 1 of the present embodiment will be described. A series of controls described below is executed by a controller (not shown). That is, the controller includes the compressors (more specifically, the motors) 2 and 3, the bypass valves 14 and 15, the shutoff valves 16 to 19, the water supply pump 20, the water supply valve 21, the pressure sensor and the water level described above. The compressor 22 is connected to the sensor 22 and the like, and the compressors 2 and 3 and the valves 14 to 19 and 21 are controlled based on the detection signal of each sensor.

制御器は、圧縮機２，３の作動条件を満たすか否かと、熱回収用熱交換器６，７への通水条件を満たすか否かとに基づき、圧縮機２，３および各弁１４〜１９，２１などを制御する。 The controller is based on whether or not the operating conditions of the compressors 2 and 3 are satisfied, and whether or not the water flow conditions to the heat exchangers 6 and 7 for heat recovery are satisfied. 19, 21, etc. are controlled.

圧縮機２，３の作動条件を満たすか否かは、典型的には、高段圧縮機３からの圧縮空気が供給されるエアタンク（または管路）の空気圧に基づき判定される。具体的には、前記圧力センサの検出信号に基づき、エアタンク内の圧力が下限圧力を下回れば、圧縮機２，３の作動条件を満たすと判定する一方、エアタンク内の圧力が上限圧力を上回れば、圧縮機２，３の作動条件を満たさないと判定する。 Whether or not the operating conditions of the compressors 2 and 3 are satisfied is typically determined based on the air pressure of the air tank (or pipe line) to which the compressed air from the high stage compressor 3 is supplied. Specifically, based on the detection signal of the pressure sensor, if the pressure in the air tank falls below the lower limit pressure, it is determined that the operating conditions of the compressors 2 and 3 are satisfied, while if the pressure in the air tank exceeds the upper limit pressure. It is determined that the operating conditions of the compressors 2 and 3 are not satisfied.

熱回収用熱交換器６，７への通水条件を満たすか否かは、典型的には、給水タンク１０内の水位に基づき判定される。具体的には、水位センサ２２の検出信号に基づき、給水タンク１０内の水位が下限水位を下回れば、通水条件を満たすと判定する一方、給水タンク１０内の水位が上限水位を上回れば、通水条件を満たさないと判定する。 Whether or not the water flow condition to the heat exchangers 6 and 7 for heat recovery is satisfied is typically determined based on the water level in the water supply tank 10. Specifically, based on the detection signal of the water level sensor 22, if the water level in the water supply tank 10 falls below the lower limit water level, it is determined that the water flow condition is satisfied, while if the water level in the water supply tank 10 exceeds the upper limit water level, It is determined that the water flow condition is not satisfied.

制御器は、圧縮機２，３の作動条件を満たすと判定すると、圧縮機２，３をロード状態で運転する一方、圧縮機２，３の作動条件を満たさないと判定すると、圧縮機２，３をアンロード状態とする。つまり、圧縮機２，３は、作動条件を満たすか否かに基づき、ロードとアンロードとを切り替えられる。但し、場合により、さらに、所定の停止条件で圧縮機２，３を停止し、その後、所定の起動条件で圧縮機２，３を再起動させる制御を追加してもよい。 When the controller determines that the operating conditions of the compressors 2 and 3 are satisfied, the controller operates the compressors 2 and 3 in a loaded state, while when the controller determines that the operating conditions of the compressors 2 and 3 are not satisfied, 3 is in an unloaded state. That is, the compressors 2 and 3 can be switched between loading and unloading based on whether or not the operation condition is satisfied. However, in some cases, a control may be added that stops the compressors 2 and 3 under a predetermined stop condition and then restarts the compressors 2 and 3 under a predetermined start condition.

圧縮機２，３がロード中、熱回収用熱交換器６，７への通水条件を満たすと判定すると、熱回収用熱交換器６，７に通水する一方、熱回収用熱交換器６，７への通水条件を満たさないと判定すると、熱回収用熱交換器６，７への通水を停止する。熱回収用熱交換器６，７への通水中、バイパス弁１４，１５を閉じて各遮断弁１６〜１９を開けた熱回収可能状態にする一方、熱回収用熱交換器６，７への通水停止中、バイパス弁１４，１５を開けて各遮断弁１６〜１９を閉じた熱回収停止状態にする。 When the compressors 2 and 3 are loaded, if it is determined that the water flow condition to the heat exchangers 6 and 7 is satisfied, the water is passed to the heat exchangers 6 and 7, while the heat exchanger If it determines with not satisfy | filling the water flow conditions to 6 and 7, the water flow to the heat exchangers 6 and 7 for heat recovery will be stopped. While passing through the heat exchangers 6 and 7 for heat recovery, the bypass valves 14 and 15 are closed and the shut-off valves 16 to 19 are opened to enable heat recovery, while the heat recovery heat exchangers 6 and 7 are connected to the heat recovery heat exchangers 6 and 7. During the stoppage of water flow, the bypass valves 14 and 15 are opened, and the shutoff valves 16 to 19 are closed to a heat recovery stop state.

具体的には、制御器は、圧縮機２，３の作動条件を満たし、且つ熱回収用熱交換器６，７への通水条件を満たすと判定する場合、圧縮機２，３をロード状態で運転すると共に、給水弁２１を開いて熱回収用熱交換器６，７に通水する。これにより、圧縮空気が製造されると共に、給水路１１を介して給水タンク１０へ給水される。この際、バイパス弁１４，１５を閉じる一方、各遮断弁１６〜１９を開ける。従って、低段圧縮機２からの圧縮空気は、第一バイパス路１２を通らず第一熱回収用熱交換器６を介してインタークーラ４へ送られ、高段圧縮機３にてさらに圧縮された後、第二バイパス路１３を通らず第二熱回収用熱交換器７を介してアフタークーラ５へ送られる。 Specifically, when the controller determines that the operating conditions of the compressors 2 and 3 are satisfied and the water flow conditions to the heat exchangers 6 and 7 for heat recovery are satisfied, the compressors 2 and 3 are loaded. The water supply valve 21 is opened and water is passed through the heat recovery heat exchangers 6 and 7. Thus, compressed air is produced and supplied to the water supply tank 10 through the water supply passage 11. At this time, the shutoff valves 16 to 19 are opened while the bypass valves 14 and 15 are closed. Therefore, the compressed air from the low stage compressor 2 is sent to the intercooler 4 through the first heat recovery heat exchanger 6 without passing through the first bypass 12, and further compressed by the high stage compressor 3. After that, it is sent to the aftercooler 5 through the second heat recovery heat exchanger 7 without passing through the second bypass 13.

給水タンク１０への給水は、熱回収用熱交換器６，７において、圧縮空気と熱交換して、圧縮空気を冷却する一方、自身は加温される。前述した温度センサの検出温度に基づき給水弁２１の開度を調整すれば、給水タンク１０への給水温度を調整することができる。但し、圧縮機２，３がロードとアンロードとの二段階で切り替えられるので、必ずしも給水流量を無段階で調整する必要はない。後述するように、本実施例の熱回収システム１では、圧縮機２，３のロード時だけでなくアンロード時にも熱回収用熱交換器６，７に通水され得るが、圧縮機２，３がロード時の第一設定流量と、圧縮機２，３がアンロード時の第二設定流量（但し第二設定流量＜第一設定流量）との二段階で、熱回収用熱交換器６，７への通水流量を変更してもよい。具体的には、前記熱回収可能状態において熱回収用熱交換器６，７に通水する際、圧縮機２，３がロード中には、給水弁２１を所定の第一開度に維持し、圧縮機２，３がアンロード中には、給水弁２１を前記第一開度よりも狭めた所定の第二開度に維持してもよい。なお、熱回収用熱交換器６，７において圧縮空気を所定温度まで冷却できない場合、熱回収用熱交換器６，７よりも圧縮空気流の下流に設けられたエアクーラ（インタークーラ４またはアフタークーラ５）において、各段の圧縮空気は所定温度まで冷却される。 The water supply to the water supply tank 10 is heat-exchanged with the heat recovery heat exchangers 6 and 7 by exchanging heat with the compressed air to cool the compressed air. If the opening degree of the water supply valve 21 is adjusted based on the temperature detected by the temperature sensor, the water supply temperature to the water supply tank 10 can be adjusted. However, since the compressors 2 and 3 are switched in two stages of loading and unloading, it is not always necessary to adjust the feed water flow rate steplessly. As will be described later, in the heat recovery system 1 of the present embodiment, water can be passed to the heat recovery heat exchangers 6 and 7 not only when the compressors 2 and 3 are unloaded but also when the compressors 2 and 3 are unloaded. 3 is a first set flow rate when loading and a second set flow rate when the compressors 2 and 3 are unloaded (where the second set flow rate is less than the first set flow rate). , 7 may be changed. Specifically, when water is passed through the heat recovery heat exchangers 6 and 7 in the heat recoverable state, the water supply valve 21 is maintained at a predetermined first opening while the compressors 2 and 3 are loaded. During the unloading of the compressors 2 and 3, the water supply valve 21 may be maintained at a predetermined second opening that is narrower than the first opening. When the compressed air cannot be cooled to a predetermined temperature in the heat recovery heat exchangers 6 and 7, an air cooler (intercooler 4 or after cooler) provided downstream of the heat recovery heat exchangers 6 and 7 in the compressed air flow. In 5), the compressed air at each stage is cooled to a predetermined temperature.

熱回収用熱交換器６，７への通水中に、圧縮機２，３の作動条件を満たさないようになり、圧縮機２，３がロードからアンロードへ切り替わった際には、熱回収用熱交換器６，７への通水条件を満たす限り、熱回収用熱交換器６，７への通水を継続する。この際、圧縮空気の流路を切り替える必要はなく、熱回収可能状態のままで足りる。その後、設定時間を超えると（つまり熱回収用熱交換器６，７へ通水しつつの圧縮機２，３のアンロード時間が設定時間を超えると）、熱回収用熱交換器６，７への通水を停止するのがよい。この場合、その後、圧縮機２，３がロードになれば、再び、熱回収用熱交換器６，７への通水を開始する。 When the operating conditions of the compressors 2 and 3 are not satisfied during the flow of water to the heat exchangers 6 and 7 for heat recovery, and the compressors 2 and 3 are switched from load to unload, As long as the water flow condition to the heat exchangers 6 and 7 is satisfied, the water flow to the heat recovery heat exchangers 6 and 7 is continued. At this time, it is not necessary to switch the flow path of the compressed air, and the heat recoverable state is sufficient. Thereafter, when the set time is exceeded (that is, when the unload time of the compressors 2 and 3 passing through the heat recovery heat exchangers 6 and 7 exceeds the set time), the heat recovery heat exchangers 6 and 7 It is better to stop the water flow to. In this case, when the compressors 2 and 3 are subsequently loaded, water flow to the heat recovery heat exchangers 6 and 7 is started again.

なお、圧縮機２，３がアンロード中、熱回収用熱交換器６，７に通水する際、その通水流量は、圧縮機２，３がロード中の通水流量よりも少ない設定流量とするのがよい。具体的には、熱回収用熱交換器６，７への通水流量は、圧縮機２，３がロード時の第一設定流量と、圧縮機２，３がアンロード時の第二設定流量との二段階で切り替えられ、第二設定流量は第一設定流量よりも少ない流量とするのがよい。これにより、ロード中よりも水温の低い水の給水タンク１０への供給量を抑制することができる。 When the compressors 2 and 3 are passing through the heat recovery heat exchangers 6 and 7 during unloading, the flow rate is lower than the flow rate during which the compressors 2 and 3 are loaded. It is good to do. Specifically, the water flow rates to the heat recovery heat exchangers 6 and 7 are the first set flow rate when the compressors 2 and 3 are loaded and the second set flow rate when the compressors 2 and 3 are unloaded. The second set flow rate is preferably smaller than the first set flow rate. Thereby, the supply_amount | feed_rate to the water supply tank 10 of water whose water temperature is lower than the load can be suppressed.

一方、制御器は、圧縮機２，３の作動条件を満たすが、熱回収用熱交換器６，７への通水条件を満たさないと判定する場合、圧縮機２，３をロード状態で運転するが、給水弁２１を閉じて熱回収用熱交換器６，７への通水を停止する。これにより、圧縮空気が製造されるが、給水路１１を介した給水タンク１０への給水は停止される。この際、バイパス弁１４，１５を開ける一方、各遮断弁１６〜１９を閉じる。従って、低段圧縮機２からの圧縮空気は、第一熱回収用熱交換器６を通らず第一バイパス路１２を介してインタークーラ４へ送られ、高段圧縮機３にてさらに圧縮された後、第二熱回収用熱交換器７を通らず第二バイパス路１３を介してアフタークーラ５へ送られる。この場合、エアクーラ（インタークーラ４またはアフタークーラ５）において、各段の圧縮空気は所定温度まで冷却される。なお、熱回収用熱交換器６，７への通水停止中に、圧縮機２，３がロードからアンロードへ切り替わった際には、熱回収用熱交換器６，７への通水停止を継続する。 On the other hand, if the controller satisfies the operating conditions of the compressors 2 and 3 but determines that the water flow conditions to the heat exchangers 6 and 7 for heat recovery are not satisfied, the controller 2 and 3 are operated in a loaded state. However, the water supply valve 21 is closed to stop the water flow to the heat recovery heat exchangers 6 and 7. Thereby, although compressed air is manufactured, the water supply to the water supply tank 10 via the water supply path 11 is stopped. At this time, the bypass valves 14 and 15 are opened, and the shutoff valves 16 to 19 are closed. Therefore, the compressed air from the low stage compressor 2 is sent to the intercooler 4 through the first bypass 12 without passing through the first heat recovery heat exchanger 6 and further compressed by the high stage compressor 3. Then, the second heat recovery heat exchanger 7 is not passed through the second bypass passage 13 and sent to the aftercooler 5. In this case, in the air cooler (intercooler 4 or aftercooler 5), the compressed air at each stage is cooled to a predetermined temperature. When the compressors 2 and 3 are switched from loading to unloading while the water flow to the heat recovery heat exchangers 6 and 7 is stopped, the water flow to the heat recovery heat exchangers 6 and 7 is stopped. Continue.

また、制御器は、圧縮機２，３の作動条件を満たさないと判定する場合、熱回収用熱交換器６，７への通水条件を満たすか否かに関わらず、圧縮機２，３をアンロード状態にする。この場合において、前述したように、熱回収用熱交換器６，７への通水中に、圧縮機２，３がロードからアンロードに切り替わった際には、熱回収用熱交換器６，７への通水条件を満たす限り、熱回収用熱交換器６，７への通水を継続する。一方、これ以外のアンロード時は、熱回収用熱交換器６，７へは通水しない。よって、熱回収用熱交換器６，７への通水停止中に、圧縮機２，３がロードからアンロードに切り替わった際には、熱回収用熱交換器６，７への通水停止を継続する。 Further, when the controller determines that the operating conditions of the compressors 2 and 3 are not satisfied, the compressors 2 and 3 regardless of whether or not the water flow conditions to the heat exchangers 6 and 7 for heat recovery are satisfied. Is unloaded. In this case, as described above, when the compressors 2 and 3 are switched from loading to unloading while passing through the heat recovery heat exchangers 6 and 7, the heat recovery heat exchangers 6 and 7 are switched. As long as the water flow condition is satisfied, the water flow to the heat recovery heat exchangers 6 and 7 is continued. On the other hand, during unloading other than this, water is not passed through the heat recovery heat exchangers 6 and 7. Therefore, when the compressors 2 and 3 are switched from loading to unloading while the water flow to the heat recovery heat exchangers 6 and 7 is stopped, the water flow to the heat recovery heat exchangers 6 and 7 is stopped. Continue.

本実施例の熱回収システム１によれば、熱回収用熱交換器６，７への通水中に、圧縮機２，３がロードからアンロードへ切り替わった際には、熱回収用熱交換器６，７への通水条件を満たす限り、熱回収用熱交換器６，７への通水を継続する一方、熱回収用熱交換器６，７への通水停止中に、圧縮機２，３がロードからアンロードへ切り替わった際には、熱回収用熱交換器６，７への通水停止を継続することで、ロードとアンロードとが切り替えられる度に、熱回収用熱交換器６，７への通水の有無が切り替えらえるのを防止することができる。これにより、熱回収用熱交換器６，７への通水用の給水ポンプ２０の頻繁な発停を抑えるなど、水処理設備の保護を図ることができる。 According to the heat recovery system 1 of the present embodiment, when the compressors 2 and 3 are switched from loading to unloading while passing through the heat recovery heat exchangers 6 and 7, the heat recovery heat exchanger As long as the water flow condition to the heat exchangers 6 and 7 is satisfied, the water flow to the heat recovery heat exchangers 6 and 7 is continued, while the water flow to the heat recovery heat exchangers 6 and 7 is stopped. , 3 is switched from loading to unloading, by continuing to stop water flow to the heat recovery heat exchangers 6 and 7, each time the load and unloading are switched, heat exchange for heat recovery It is possible to prevent the presence or absence of water flow to the vessels 6 and 7 from being switched. Thereby, protection of water treatment equipment can be aimed at, such as suppressing frequent start and stop of water supply pump 20 for water flow to heat exchangers 6 and 7 for heat recovery.

ところで、圧縮機２，３をロード運転中、熱回収可能状態から熱回収停止状態へ切り替える際、先にバイパス弁１４，１５を開いてから、各遮断弁１６〜１９を閉じるのがよい。同様に、圧縮機２，３をロード運転中、熱回収停止状態から熱回収可能状態へ切り替える際、先に各遮断弁１６〜１９を開いてから、バイパス弁１４，１５を閉じるのがよい。熱回収用熱交換器６，７経由とバイパス路１２，１３経由との双方に一時的に圧縮空気が流れるよう制御することで、弁の動作遅れによる不都合、具体的には圧縮空気の流れの遮断による圧縮機２，３の不具合を防止することができる。 By the way, when the compressors 2 and 3 are switched from the heat recoverable state to the heat recovery stopped state during the load operation, the shutoff valves 16 to 19 are preferably closed after the bypass valves 14 and 15 are opened first. Similarly, when the compressors 2 and 3 are switched from the heat recovery stopped state to the heat recoverable state during the load operation, it is preferable to open the shut-off valves 16 to 19 first and then close the bypass valves 14 and 15. By controlling the compressed air to temporarily flow through both the heat recovery heat exchangers 6 and 7 and the bypass passages 12 and 13, inconvenience caused by valve operation delay, specifically, the flow of the compressed air The malfunction of the compressors 2 and 3 by interruption | blocking can be prevented.

また、圧縮機２，３をロード運転中、熱回収用熱交換器６，７への通水停止状態から通水状態へ切り替える際、給水弁２１を開いてから各遮断弁１６〜１９を開くのが好ましい。特に、給水弁２１を開いて、前述の流量計で所定流量以上の通水を確認してから、各遮断弁１６〜１９を開くのが好ましい。これにより、熱回収用熱交換器６，７への通水が停止中なのに熱回収用熱交換器６，７へ圧縮空気が流入するのを防止して、熱回収用熱交換器６，７内の水の沸騰を防止できると共に、空焚きによる熱回収用熱交換器６，７における熱応力の増大とそれによる破損を防止できる。同様の理由で、圧縮機２，３をロード運転中、熱回収用熱交換器６，７への通水状態から通水停止状態へ切り替える際、バイパス弁１４，１５を開ける一方、各遮断弁１６〜１９を閉じてから、給水弁２１を閉じるのが好ましい。 Further, during the load operation of the compressors 2 and 3, when switching from the water flow stop state to the heat recovery heat exchangers 6 and 7 to the water flow state, the water supply valve 21 is opened and then the shutoff valves 16 to 19 are opened. Is preferred. In particular, it is preferable to open the water supply valve 21 and open the shut-off valves 16 to 19 after confirming the passage of water at a predetermined flow rate or higher with the aforementioned flow meter. This prevents the compressed air from flowing into the heat recovery heat exchangers 6 and 7 even though the water flow to the heat recovery heat exchangers 6 and 7 is stopped, and the heat recovery heat exchangers 6 and 7. It is possible to prevent boiling of the water in the inside, and to prevent an increase in thermal stress in the heat recovery heat exchangers 6 and 7 due to air blowing and damage caused thereby. For the same reason, when the compressors 2 and 3 are loaded, the bypass valves 14 and 15 are opened when the water flow to the heat recovery heat exchangers 6 and 7 is switched from the water flow to the water flow stop state. It is preferable to close the water supply valve 21 after closing 16-19.

図２は、本発明の熱回収システム１の実施例２を示す概略図である。
本実施例２の熱回収システム１も、基本的には前記実施例１と同様である。そこで、以下においては、両者の異なる点を中心に説明し、対応する箇所には同一の符号を付して説明する。 FIG. 2 is a schematic diagram showing Example 2 of the heat recovery system 1 of the present invention.
The heat recovery system 1 according to the second embodiment is basically the same as the first embodiment. Therefore, in the following description, differences between the two will be mainly described, and corresponding portions will be described with the same reference numerals.

前記実施例１では、熱回収用熱交換器６，７に通水するための給水路１１には、給水弁２１として開度調整可能な電動弁（モータバルブ）を設けたが、本実施例２では、以下のようにオンオフ弁として電磁弁を用いて、熱回収用熱交換器６，７への通水流量が、第一設定流量と、これより小流量の第二設定流量との二段階で切り替えられる。 In the first embodiment, an electric valve (motor valve) whose opening degree can be adjusted is provided as the water supply valve 21 in the water supply passage 11 for passing water to the heat exchangers 6 and 7 for heat recovery. 2, using a solenoid valve as an on / off valve as described below, the flow rate of water to the heat exchangers 6 and 7 for heat recovery is set to a first set flow rate and a second set flow rate smaller than this. Switchable in stages.

具体的には、熱回収用熱交換器６，７への給水路１１には、第一電磁弁２３を備えた第一給水路１１Ａと、第二電磁弁２４を備えた第二給水路１１Ｂとが並列に設けられている。言い換えれば、前記実施例１において、電動弁（給水弁）２１に代えて第一電磁弁２３を設けると共に、その前後をバイパスするように第二給水路１１Ｂを設けている。そして、第二給水路１１Ｂの両端部間に挟まれた給水路を、第一給水路１１Ａとしている。第一給水路１１Ａには第一電磁弁２３が設けられる一方、第二給水路１１Ｂには第二電磁弁２４が設けられる。 Specifically, in the water supply path 11 to the heat exchangers 6 and 7 for heat recovery, the first water supply path 11A including the first electromagnetic valve 23 and the second water supply path 11B including the second electromagnetic valve 24 are provided. Are provided in parallel. In other words, in the first embodiment, the first electromagnetic valve 23 is provided in place of the motor operated valve (water supply valve) 21 and the second water supply passage 11B is provided so as to bypass the front and rear thereof. And the water supply path pinched | interposed between the both ends of the 2nd water supply path 11B is made into the 1st water supply path 11A. The first electromagnetic valve 23 is provided in the first water supply path 11A, while the second electromagnetic valve 24 is provided in the second water supply path 11B.

前記実施例１における給水弁２１の制御に代えて、本実施例２では各電磁弁２３，２４の開閉が制御される。第二給水路１１Ｂは第一給水路１１Ａよりも管径が細く形成されているので、第一電磁弁２３と第二電磁弁２４との双方を開くか（あるいは第一電磁弁２３のみを開くか）、第二電磁弁２４のみを開くかにより、熱回収用熱交換器６，７への通水流量を二段階で切り替えることができる。もちろん、両電磁弁２３，２４を閉じれば、熱回収用熱交換器６，７への通水を停止することができる。なお、本実施例２では、第一電磁弁２３と第二電磁弁２４との内、一方でも開放状態とする際、給水ポンプ２０を作動させ、双方を閉鎖状態とする際、給水ポンプ２０を停止させる。 Instead of controlling the water supply valve 21 in the first embodiment, the opening and closing of the electromagnetic valves 23 and 24 is controlled in the second embodiment. Since the 2nd water supply path 11B is formed in the pipe diameter narrower than the 1st water supply path 11A, both the 1st solenoid valve 23 and the 2nd solenoid valve 24 are opened (or only the 1st solenoid valve 23 is opened). The flow rate of water to the heat exchangers 6 and 7 for heat recovery can be switched in two stages depending on whether only the second solenoid valve 24 is opened. Of course, if both solenoid valves 23 and 24 are closed, water flow to the heat recovery heat exchangers 6 and 7 can be stopped. In the second embodiment, when one of the first solenoid valve 23 and the second solenoid valve 24 is in an open state, the feed pump 20 is operated and both are closed. Stop.

本実施例２でも、前記実施例１と同様に、圧縮機２，３がロード中、熱回収用熱交換器６，７への通水条件を満たすと、熱回収可能状態にすると共に熱回収用熱交換器６，７に通水する一方、熱回収用熱交換器６，７への通水条件を満たさないと、熱回収停止状態にすると共に熱回収用熱交換器６，７への通水を停止する。そして、圧縮機２，３がロード中、熱回収用熱交換器６，７へ通水する際、第一電磁弁２３と第二電磁弁２４との双方を開く（あるいは第一電磁弁２３のみを開く）ことで、比較的大流量で通水する。 Also in the second embodiment, as in the first embodiment, when the compressors 2 and 3 are loaded and the water flow condition to the heat exchangers 6 and 7 for heat recovery is satisfied, the heat recovery is enabled and the heat recovery is performed. If the water passage conditions to the heat exchangers 6 and 7 are not satisfied but the water passage conditions to the heat exchangers 6 and 7 are not satisfied, the heat recovery is stopped and the heat exchangers 6 and 7 are connected. Stop water flow. When the compressors 2 and 3 are loaded, when passing water to the heat recovery heat exchangers 6 and 7, both the first solenoid valve 23 and the second solenoid valve 24 are opened (or only the first solenoid valve 23). The water is passed at a relatively large flow rate.

一方、熱回収用熱交換器６，７への通水中に、圧縮機２，３がロードからアンロードへ切り替わった際には、熱回収用熱交換器６，７への通水条件を満たす限り、熱回収用熱交換器６，７への通水を継続する。この際、第二電磁弁２４のみを開いて、比較的小流量で通水する。なお、熱回収用熱交換器６，７への通水停止中に、圧縮機２，３がロードからアンロードへ切り替わった際には、熱回収用熱交換器６，７への通水停止を継続する。 On the other hand, when the compressors 2 and 3 are switched from loading to unloading during passage of water to the heat recovery heat exchangers 6 and 7, the water flow conditions to the heat recovery heat exchangers 6 and 7 are satisfied. As long as the water flow to the heat recovery heat exchangers 6 and 7 continues. At this time, only the second electromagnetic valve 24 is opened and water is passed at a relatively small flow rate. When the compressors 2 and 3 are switched from loading to unloading while the water flow to the heat recovery heat exchangers 6 and 7 is stopped, the water flow to the heat recovery heat exchangers 6 and 7 is stopped. Continue.

このようにして、ロードとアンロードとが切り替えられる度に、熱回収用熱交換器６，７への通水の有無が切り替えらえるのを防止することができる。これにより、熱回収用熱交換器６，７への通水用の給水ポンプ２０の頻繁な発停を抑えるなど、水処理設備の保護を図ることができる。その他の構成（制御を含む）は、前記実施例１と同様のため、説明を省略する。 In this way, it is possible to prevent the presence or absence of water flow to the heat recovery heat exchangers 6 and 7 from being switched each time switching between loading and unloading. Thereby, protection of water treatment equipment can be aimed at, such as suppressing frequent start and stop of water supply pump 20 for water flow to heat exchangers 6 and 7 for heat recovery. Other configurations (including control) are the same as those in the first embodiment, and thus description thereof is omitted.

本発明の熱回収システム１は、前記実施例（変形例を含む）の構成に限らず適宜変更可能である。特に、圧縮機２，３からの圧縮空気をバイパス路１２，１３に通さずに熱回収用熱交換器６，７を介してエアクーラ４，５へ送る熱回収可能状態と、圧縮機２，３からの圧縮空気を熱回収用熱交換器６，７に通さずにバイパス路１２，１３を介してエアクーラ４，５へ送る熱回収停止状態とを切り替え可能とされ、圧縮機２，３がアンロード中、熱回収用熱交換器６，７への圧縮空気の流通はないが、設定条件において熱回収用熱交換器６，７に通水可能であれば、その他の構成は適宜に変更可能である。 The heat recovery system 1 of the present invention is not limited to the configuration of the above-described embodiment (including modifications), and can be changed as appropriate. In particular, a heat recoverable state in which compressed air from the compressors 2 and 3 is sent to the air coolers 4 and 5 through the heat recovery heat exchangers 6 and 7 without passing through the bypass passages 12 and 13, and the compressors 2 and 3 It is possible to switch between a heat recovery stop state in which the compressed air from the air is not passed through the heat recovery heat exchangers 6 and 7 and is sent to the air coolers 4 and 5 via the bypass passages 12 and 13. While loading, there is no flow of compressed air to the heat recovery heat exchangers 6 and 7, but other configurations can be changed as long as water can be passed to the heat recovery heat exchangers 6 and 7 under the set conditions. It is.

たとえば、前記各実施例では、熱回収用熱交換器６，７の入口側および出口側の双方に遮断弁１６（１７），１８（１９）を設けたが、その内、一方の設置を省略することができる。熱交入口側遮断弁１６，１７と熱交出口側遮断弁１８，１９との内、一方の遮断弁の設置を省略しても、他方の遮断弁の閉鎖により、熱回収用熱交換器６，７への圧縮空気の流通を防止することができる。また、バイパス弁１４，１５と各遮断弁１６〜１９との設置に代えて、たとえば、熱交入口側空気路８ａ，９ａとバイパス路１２，１３との分岐部に三方弁を設けるか、熱交出口側空気路８ｂ，９ｂとバイパス路１２，１３との合流部に三方弁を設けてもよい。 For example, in each of the above embodiments, the shutoff valves 16 (17) and 18 (19) are provided on both the inlet side and the outlet side of the heat recovery heat exchangers 6 and 7, but one of them is omitted. can do. Even if the installation of one of the heat exchange inlet side shutoff valves 16 and 17 and the heat exchange outlet side shutoff valves 18 and 19 is omitted, the heat recovery heat exchanger 6 is closed by closing the other shutoff valve. , 7 can be prevented from flowing. Further, instead of installing the bypass valves 14 and 15 and the shut-off valves 16 to 19, for example, a three-way valve is provided at a branch portion between the heat exchange inlet air paths 8a and 9a and the bypass paths 12 and 13, or heat You may provide a three-way valve in the junction part of the air outlet side air paths 8b and 9b and the bypass paths 12 and 13. FIG.

また、前記実施例では、インタークーラ４およびアフタークーラは５、圧縮機２，３からの圧縮空気を、冷却塔との間の循環水で冷却する水冷式としたが、インタークーラ４とアフタークーラ５との内、一方または双方は空冷式としてもよい。インタークーラ４および／またはアフタークーラ５を空冷式とする場合、その空冷式熱交換器において、圧縮機２，３からの圧縮空気をファンによる通風で冷却することになる。つまり、空冷式熱交換器において、圧縮機２，３からの圧縮空気と、ファンによる通風とを、混ぜることなく間接熱交換させてもよい。 Moreover, in the said Example, although the intercooler 4 and the aftercooler were set to the water-cooling type which cools the compressed air from the compressors 2 and 3 with the circulating water between cooling towers, the intercooler 4 and an aftercooler are used. One or both of 5 may be air-cooled. When the intercooler 4 and / or the aftercooler 5 is air-cooled, in the air-cooled heat exchanger, the compressed air from the compressors 2 and 3 is cooled by ventilation with a fan. That is, in the air-cooled heat exchanger, indirect heat exchange may be performed without mixing the compressed air from the compressors 2 and 3 and the ventilation by the fan.

また、前記実施例では、熱回収用熱交換器６，７に、ボイラの給水タンク１０への給水を通して、ボイラの給水の予熱を図る例を示したが、熱回収用熱交換器６，７に通す水の用途はこれに限らず適宜変更可能である。また、熱回収用熱交換器６，７への通水条件の有無は、場合により、熱回収用熱交換器６，７を通過後の温水を用いる温水使用設備からの信号を利用してもよい。 In the above-described embodiment, an example is shown in which the boiler water supply is preheated through the water supply to the boiler water supply tank 10 through the heat recovery heat exchangers 6 and 7, but the heat recovery heat exchangers 6 and 7 are used. The use of the water passed through is not limited to this and can be changed as appropriate. In addition, the presence or absence of water flow conditions to the heat recovery heat exchangers 6 and 7 may be determined by using a signal from a hot water use facility that uses hot water after passing through the heat recovery heat exchangers 6 and 7, depending on circumstances. Good.

さらに、前記実施例において、圧縮機２，３の段数は、適宜に変更可能である。たとえば、単段の圧縮機であってもよい。その場合、前記実施例において、二つの圧縮機２，３の内の一方の設置を省略し、それに伴い、その圧縮機２（３）の直後に設置された熱回収用熱交換器６（７）とエアクーラ４（５）の設置を省略すればよい。たとえば、図１および図２において、高段圧縮機３、第二熱回収用熱交換器７およびアフタークーラ５の設置を省略することができる。逆に、図１および図２において、圧縮機を三段以上としてもよく、それに伴い、圧縮機２（３）、熱回収用熱交換器６（７）およびエアクーラ４（５）のセットの設置台数を増やせばよい。そして、追加された熱回収用熱交換器についても、バイパス路などが設けられ、前記実施例と同様に制御される。 Furthermore, in the said Example, the number of stages of the compressors 2 and 3 can be changed suitably. For example, a single-stage compressor may be used. In that case, in the said Example, installation of one of the two compressors 2 and 3 is abbreviate | omitted, and in connection with it, the heat exchanger 6 (7 for heat recovery) installed immediately after the compressor 2 (3). ) And the air cooler 4 (5) may be omitted. For example, in FIGS. 1 and 2, the installation of the high stage compressor 3, the second heat recovery heat exchanger 7 and the aftercooler 5 can be omitted. On the contrary, in FIGS. 1 and 2, the compressor may have three or more stages, and accordingly, a set of compressor 2 (3), heat recovery heat exchanger 6 (7) and air cooler 4 (5) is installed. Just increase the number. The added heat recovery heat exchanger is also provided with a bypass and is controlled in the same manner as in the above embodiment.

１熱回収システム
２低段圧縮機
３高段圧縮機
４インタークーラ（エアクーラ）
５アフタークーラ（エアクーラ）
６第一熱回収用熱交換器
７第二熱回収用熱交換器
８第一空気路（８ａ：第一熱交入口側空気路、８ｂ：第一熱交出口側空気路）
９第二空気路（９ａ：第二熱交入口側空気路、９ｂ：第二熱交出口側空気路）
１０給水タンク
１１給水路（１１Ａ：第一給水路、１１Ｂ：第二給水路）
１２第一バイパス路
１３第二バイパス路
１４第一バイパス弁
１５第二バイパス弁
１６第一熱交入口側遮断弁
１７第二熱交入口側遮断弁
１８第一熱交出口側遮断弁
１９第二熱交出口側遮断弁
２０給水ポンプ
２１給水弁
２２水位センサ
２３第一電磁弁
２４第二電磁弁 1 Heat recovery system 2 Low stage compressor 3 High stage compressor 4 Intercooler (air cooler)
5 After cooler (air cooler)
6 heat exchanger for first heat recovery 7 heat exchanger for second heat recovery 8 first air path (8a: first heat exchange inlet side air path, 8b: first heat exchange outlet side air path)
9 second air passage (9a: second heat exchange inlet side air passage, 9b: second heat exchange outlet side air passage)
10 water supply tanks 11 water supply channels (11A: first water supply channel, 11B: second water supply channel)
12 1st bypass path 13 2nd bypass path 14 1st bypass valve 15 2nd bypass valve 16 1st heat exchange inlet side shut-off valve 17 2nd heat exchange inlet side shut-off valve 18 1st heat exchange outlet side shut-off valve 19 2nd Heat exchanger outlet side shutoff valve 20 Water supply pump 21 Water supply valve 22 Water level sensor 23 First solenoid valve 24 Second solenoid valve

Claims

An air cooler that cools the compressed air from the oil-free compressor with circulating water between the cooling tower or the ventilation by a fan;
A heat exchanger for heat recovery, which is provided in an air path from the compressor to the air cooler, and produces hot water by exchanging heat between the compressed air and water;
An air path from the compressor to the heat recovery heat exchanger and a bypass path connecting the air path from the heat recovery heat exchanger to the air cooler;
A heat recoverable state in which compressed air from the compressor is sent to the air cooler via the heat recovery heat exchanger without passing through the bypass passage; and compressed air from the compressor is transferred to the heat recovery heat exchanger It is possible to switch between a heat recovery stop state sent to the air cooler via the bypass path without passing through,
The compressor is a load / unload machine,
During the unloading of the compressor, there is no flow of compressed air to the heat recovery heat exchanger, but water can be passed through the heat recovery heat exchanger.

When the compressor is loaded, if the water flow condition to the heat recovery heat exchanger is satisfied, the heat recovery state and the heat recovery heat exchanger are passed while the heat recovery heat exchange is performed. If the water flow condition to the heat exchanger is not satisfied, the heat recovery is stopped and the water flow to the heat recovery heat exchanger is stopped,
When the compressor is switched from loading to unloading during water flow to the heat recovery heat exchanger, the heat recovery heat exchange is performed as long as the water flow condition to the heat recovery heat exchanger is satisfied. Continue water flow to the vessel,
While the flow of water to the heat recovery heat exchanger is stopped, when the compressor is switched from loading to unloading, the flow of water to the heat recovery heat exchanger is stopped. The heat recovery system according to claim 1.

The water flow to the heat recovery heat exchanger is stopped when the unload time of the compressor exceeds a set time while water is passed to the heat recovery heat exchanger. Item 3. The heat recovery system according to Item 2.

The water flow rate to the heat recovery heat exchanger is switched in two stages, a first set flow rate when the compressor is loaded and a second set flow rate when the compressor is unloaded,
The heat recovery system according to any one of claims 1 to 3, wherein the second set flow rate is lower than the first set flow rate.

In the water supply path to the heat recovery heat exchanger, a first water supply path provided with a first electromagnetic valve and a second water supply path provided with a second electromagnetic valve are provided in parallel.
The second water supply channel is formed with a smaller pipe diameter than the first water supply channel,
When the water is passed through the heat recovery heat exchanger, if the compressor is being loaded, both the first solenoid valve and the second solenoid valve are opened or the first solenoid valve is opened, and the compressor is unloaded. The heat recovery system according to claim 4, wherein the second solenoid valve is opened during loading.

As the compressor, comprising a low-stage compressor and a high-stage compressor,
As the air cooler, an intercooler and an aftercooler are provided,
As the heat recovery heat exchanger, it comprises a first heat recovery heat exchanger and a second heat recovery heat exchanger,
Compressed air from the low-stage compressor is sent to the high-stage compressor via the intercooler, further compressed in the high-stage compressor, and then sent to the aftercooler,
While the first heat recovery heat exchanger is provided in the air path from the low stage compressor to the intercooler, the second heat recovery is provided in the air path from the high stage compressor to the after cooler. A heat exchanger is provided,
In the first heat recovery heat exchanger and the second heat recovery heat exchanger, water is passed in series in a set order, or water is passed in parallel,
The heat recovery system according to any one of claims 1 to 5, wherein the bypass path is provided for each heat recovery heat exchanger.