Gas compression device

Abstract

To provide a gas compression device that can prevent condensation of gas in a pipe connecting an exhaust heat recovery part and a compressor without decreasing the amount of supply of high-pressure gas pressurized by the compressor to a utilization side.SOLUTION: A vapor compression device A1 (gas compression device) according to the present invention comprises: a second gas-liquid separator 3 (gas-liquid separation part) for generating water vapor by evaporating water, and separating the water vapor and the water; an exhaust heat recovery heat exchanger 4 (heat recovery part) for supplying the water heated by warm water to the second gas-liquid separator 3 (gas-liquid separation part); a compressor 1 for compressing the water vapor supplied from the second gas-liquid separator 3 (gas-liquid separation part); and a superheater 5 for heating the water vapor by exchanging heat between the warm water to be supplied to the exhaust heat recovery heat exchanger 4 (heat recovery part) and the water vapor to be supplied to the compressor 1 from the second gas-liquid separator 3 (gas-liquid separation part). The warm water flows through the superheater 5 and the exhaust heat recovery heat exchanger 4 in this order.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to gas compression devices. [Background technology]

[0002] Generally, low-temperature exhaust heat below 100°C is used as the driving heat source to heat and pressurize low-pressure steam generated in an exhaust heat recovery section to a high temperature exceeding 100°C in a compressor. In the piping connecting such an exhaust heat recovery section and the compressor, when heat is released due to the temperature difference between the low-pressure steam (approximately 70°C) and the outside air temperature (for example, 20°C), part of the low-pressure steam condenses and becomes drain. Drain that unexpectedly flows into the compressor prevents the compressor from supplying a stable supply of high-pressure steam. Conventionally, there is known a heat pump system in which a superheater is provided above the exhaust heat recovery section that sends low-pressure steam to a compressor, and a portion of the high-pressure steam pressurized by the compressor flows into the superheater (see, for example, Patent Document 1). In this system, saturated low-pressure steam generated in the exhaust heat recovery section is converted into superheated steam in a superheater. With this type of system, the superheated steam flows through the piping connecting the exhaust heat recovery section and the compressor, so that the generation of drainage in the piping can be prevented. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-103423 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional system described in Patent Document 1 uses part of the high-pressure steam pressurized by the compressor as a heat source for generating superheated steam from saturated low-pressure steam. Therefore, in this system, the amount of high-pressure steam pressurized by the compressor supplied to the user side is reduced.

[0005] An object of the present invention is to provide a gas compression device that can prevent condensation of gas in piping connecting an exhaust heat recovery section and a compressor without reducing the amount of high-pressure gas pressurized by the compressor supplied to the user side. [Means for solving the problem]

[0006] The gas compression device of the present invention comprises a gas-liquid separation section that evaporates a liquid to generate a gas and separates the gas and liquid, a heat recovery section that supplies liquid heated by a heat medium to the gas-liquid separation section, a compressor that compresses the gas supplied from the gas-liquid separation section, and a superheater that heats the gas by heat exchange between the heat medium supplied to the heat recovery section and the gas supplied from the gas-liquid separation section to the compressor, and is characterized in that the heat medium flows through the superheater and the heat recovery section in that order. Effect of the Invention

[0007] According to the gas compression device of the present invention, condensation of gas in the piping connecting the exhaust heat recovery section and the compressor can be prevented without reducing the amount of high-pressure gas pressurized by the compressor supplied to the utilization side. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cycle system diagram showing a configuration of a vapor compression device (gas compression device) according to a first embodiment of the present invention. [Diagram 2] FIG. 5 is a cycle system diagram showing the configuration of a vapor compression device (gas compression device) according to a second embodiment of the present invention. [Diagram 3] 3 is a flowchart illustrating a procedure executed by a control unit constituting the vapor compression device (gas compression device) of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a gas compression device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Here, the present invention will be described using as an example a steam compression device that boosts low-pressure steam (hereinafter referred to as low-pressure steam) to high-pressure steam (hereinafter referred to as high-pressure steam) using a compressor and supplies it to the user side.

[0010] The steam compression device of this embodiment is intended to recover low-temperature exhaust heat associated with hot water discharged from a steam utilization facility such as a factory, and to reuse the recovered heat when generating high-pressure steam to be supplied to the steam utilization facility. However, the user of the high-pressure steam generated from the low-pressure steam is not limited to a steam utilization facility such as a factory. Furthermore, the source of exhaust heat is not limited to a steam utilization facility such as a factory. Furthermore, as described below, the gas compression device of the present invention is not limited to compressing water vapor, but can also be applied to compress other gases that can be converted into gas-liquid form, such as fluorocarbons and low-carbon hydrocarbon gases.

[0011] First Embodiment FIG. 1 is a cycle diagram showing the configuration of a vapor compression device A1 (gas compression device) according to a first embodiment of the present invention. As shown in FIG. 1, the vapor compression device A1 includes a compressor 1, a first gas-liquid separator 2, a second gas-liquid separator 3, an exhaust heat recovery heat exchanger 4, and a superheater 5. Here, the second gas-liquid separator 3 corresponds to the “gas-liquid separation section.” The exhaust heat recovery heat exchanger 4 corresponds to the “heat recovery section.” The first gas-liquid separator 2, together with a feedwater heat exchanger denoted by reference numeral 6 and a pressure reducing valve denoted by reference numeral 10 in Fig. 1, constitutes a water supply system for the second gas-liquid separator 3 (gas-liquid separation section). The water supply system including the first gas-liquid separator 2 will be described in detail later.

[0012] The compressor 1 raises the temperature and pressure of low-pressure steam supplied from a superheater 5, which will be described later. The compressor 1 supplies the high-pressure steam discharged from the compressor 1 to a utilization side via a first gas-liquid separator 2. Although not shown, the compressor 1 in this embodiment is assumed to be a screw compressor composed of a male rotor and a female rotor. Water is supplied between the male rotor and the female rotor.

[0013] This improves the sealing performance between the male rotor and the female rotor, and efficiently compresses low-pressure steam in the compressor 1. In this embodiment, the water supplied between the male rotor and the female rotor is water from the second gas-liquid separator 3, which will be described later. This water is supplied via piping 18, and its flow rate is adjusted by a supply pump 8 and a flow control valve 9. As described later, when the superheated low-pressure steam supplied from the superheater 5 becomes high-pressure steam in the compressor 1, this water cools it to turn it into saturated high-pressure steam. The compressor 1 discharges high-temperature water together with saturated high-pressure steam to the pipe 15 side.

[0014] The second gas-liquid separator 3 (gas-liquid separation section) evaporates water to generate gas (water vapor) and separates the gas from the liquid. Here, water corresponds to the "liquid". Water vapor corresponds to the "gas". The internal pressure of the second gas-liquid separator 3 (gas-liquid separation section) is maintained close to a vacuum by suction when the compressor 1 is in operation. A predetermined amount of low-temperature water is stored in the second gas-liquid separator 3. A portion of this low-temperature water is circulated between the second gas-liquid separator 3 and a waste heat recovery heat exchanger 4 (heat recovery section) described below via pipes 19 and 20. Specifically, a predetermined amount of low-temperature water is circulated by a low-temperature water circulation pump 7 provided in the pipe 19. As a result, the low-temperature water sent out from the second gas-liquid separator 3 is heated in the waste heat recovery heat exchanger 4 (heat recovery section) as described below, and then returned to the second gas-liquid separator 3. In this embodiment, the temperature of the returned low-temperature water is assumed to be about 70° C., but is not limited to this. The temperature of this low-temperature water can be appropriately set according to the temperature of the saturated steam sent to the superheater 5, which is determined in advance at the time of design.

[0015] The second gas-liquid separator 3 (gas-liquid separation section) evaporates the returned low-temperature water under a substantially vacuum. The second gas-liquid separator 3 (gas-liquid separation section) generates low-pressure steam in a saturated state at a low temperature (about 70° C. in this embodiment). The second gas-liquid separator 3 (gas-liquid separation section) separates the low-temperature water that has not evaporated from the returned low-temperature water and stores it as stored water again. The generated low-pressure steam in a saturated state is sent to the superheater 5, which will be described later. In addition, the amount of water equivalent to the low-temperature water evaporated and consumed in the second gas-liquid separator 3 (gas-liquid separation section) and the water sent to the compressor 1 via piping 18 is replenished by water supply via the water supply heat exchanger 6 described below and return water from the first gas-liquid separator 2.

[0016] The exhaust heat recovery heat exchanger 4 (heat recovery section) heats the low-temperature water (liquid) by heat exchange between hot water supplied from a superheater 5 described below and the low-temperature water (liquid) supplied from the second gas-liquid separator 3 (gas-liquid separation section) via a pipe 19. A part of the heated low-temperature water vaporizes to become low-pressure steam below atmospheric pressure, and is sent to the second gas-liquid separator 3 together with the low-temperature water. The hot water supplied from the superheater 5 corresponds to the "heat medium". The outlet temperature of the low-temperature water (liquid) on the piping 20 side of such an exhaust heat recovery heat exchanger 4 (heat recovery section) is lower than the outlet temperature of the hot water (heat medium) in the exhaust heat recovery heat exchanger 4 (heat recovery section) due to the thermal resistance of the exhaust heat recovery heat exchanger 4.

[0017] As shown in FIG. 1, the superheater 5 heats saturated low-pressure steam (gas) by exchanging heat between hot water (heat medium) supplied to the exhaust heat recovery heat exchanger 4 (heat recovery section) and the saturated low-pressure steam (gas) supplied from the second gas-liquid separator 3 (gas-liquid separation section) to the compressor 1. As described above, the hot water (heat medium) here is assumed to be hot water of 100°C or less discharged from steam-using facilities such as factories. Specifically, hot water of about 80°C is assumed, but is not limited to this.

[0018] Hot water (heat medium) is supplied to the superheater 5 via piping 12. Saturated low-pressure steam (gas) from the second gas-liquid separator 3 (gas-liquid separation section) is supplied to the superheater 5 via piping 22. The hot water (heat medium) after heat exchange with the low-pressure steam (gas) in the superheater 5 is supplied to the exhaust heat recovery heat exchanger 4 (heat recovery section) via piping 14. The superheated low-pressure steam (gas) after heat exchange with hot water (heat medium) in the superheater 5 is supplied to the compressor 1 via the pipe 13 as described above.

[0019] The superheater 5 in this embodiment is disposed vertically above the second gas-liquid separator 3 (gas-liquid separation section). In addition, the pipe 22, which circulates low-pressure steam (gas) from the second gas-liquid separator 3 (gas-liquid separation section) to the superheater 5, is shorter than the pipe 13, which circulates low-pressure steam (gas) from the superheater 5 to the compressor 1. Such a superheater 5 is desirably disposed adjacent to the second gas-liquid separator 3 (gas-liquid separation section).

[0020] Next, a water supply system for the second gas-liquid separator 3 (gas-liquid separation section) shown in FIG. 1 will be described. In this embodiment, the water supply system for the second gas-liquid separator 3 (gas-liquid separation section) includes a first gas-liquid separator 2, a water supply heat exchanger 6, and a pressure reducing valve 10, as shown in FIG.

[0021] The first gas-liquid separator 2 separates the high-pressure steam in a saturated state, supplied from the compressor 1 via a pipe 15, from the high-temperature water. As described above, the separated high-pressure steam in a saturated state is supplied to the utilization side via a pipe 16. In addition, the first gas-liquid separator 2 supplies the separated high-temperature water to the feedwater heat exchanger 6 via a pipe 17.

[0022] On the other hand, water is supplied to the feedwater heat exchanger 6. The high-temperature water from the first gas-liquid separator 2 is cooled by supplying water to the feedwater heat exchanger 6. The cooled high-temperature water is then supplied to the second gas-liquid separator 3 (gas-liquid separation section) via the pressure reducing valve 10. The water supplied to the feedwater heat exchanger 6 is heated to approximately the same temperature as the low-temperature water in the second gas-liquid separator 3 (gas-liquid separation section) by heat exchange with the high-temperature water, and is then supplied to the second gas-liquid separator 3 (gas-liquid separation section).

[0023] <Action and effect> Next, the effects of the vapor compression device A1 (see FIG. 1) of this embodiment will be described. A vapor compression device A1 as a gas compression device of the present invention includes a second gas-liquid separator 3 (gas-liquid separation section) that evaporates water (liquid) to generate water vapor (gas) and separates the water vapor (gas) from the water (liquid), a waste heat recovery heat exchanger 4 (heat recovery section) that supplies water (liquid) heated by hot water (heat medium) to the second gas-liquid separator 3 (gas-liquid separation section), a compressor 1 that compresses the water vapor (gas) supplied from the second gas-liquid separator 3 (gas-liquid separation section), and a superheater 5 that heats the water vapor (gas) by heat exchange between the hot water (heat medium) supplied to the exhaust heat recovery heat exchanger 4 (heat recovery section) and the water vapor (gas) supplied from the second gas-liquid separator 3 (gas-liquid separation section), and is characterized in that the hot water (heat medium) flows through the superheater 5 and the exhaust heat recovery heat exchanger 4 (heat recovery section) in that order.

[0024] In such a vapor compression device A1, hot water serving as a heat source is passed through the superheater 5 and then the exhaust heat recovery heat exchanger 4, so that the saturated low-pressure steam separated in the second gas-liquid separator 3 is heated by the hot water in the superheater 5. As a result, dry superheated low-pressure steam is sent to the compressor 1. Unlike conventional systems (see, for example, Patent Document 1), this vapor compression device A1 can prevent condensation of water vapor in the pipe 13 connecting the exhaust heat recovery heat exchanger 4 and the compressor 1, without reducing the amount of high-pressure steam pressurized by the compressor 1 supplied to the utilization side. The vapor compression device A1 can supply the entire amount of high-pressure steam pressurized by the compressor 1 to the utilization side.

[0025] In addition, in such a vapor compression device A1, the exhaust heat recovery heat exchanger 4 (heat recovery section) constitutes a heat exchanger that heats the water (liquid) by exchanging heat between the hot water (heat medium) supplied from the superheater 5 and the water (liquid) supplied from the second gas-liquid separator 3 (gas-liquid separation section).

[0026] In such a vapor compression device A1, hot water serving as a heat source first flows into the superheater 5, and then flows into the exhaust heat recovery heat exchanger 4. Therefore, the temperature of the hot water flowing into the exhaust heat recovery heat exchanger 4 drops by the amount of heat exchanged in the superheater 5. In addition, the temperature of the low-temperature water heated by the hot water in the exhaust heat recovery heat exchanger 4 drops by the amount of thermal resistance of the exhaust heat recovery heat exchanger 4.

[0027] Specifically, for example, when hot water at 80°C flows into the superheater 5, the hot water that has been heat exchanged in the superheater 5 and has reached 79°C flows into the exhaust heat recovery heat exchanger 4. Assuming that the hot water exchanges heat with low-temperature water in the exhaust heat recovery heat exchanger 4 and flows out at 72°C, the saturated low-temperature water can be evaporated at about 70°C, which is lower than the hot water temperature of 72°C at the outlet of the exhaust heat recovery heat exchanger 4, due to the thermal resistance of the heat exchanger. This makes it possible to set a large thermal gradient during heat exchange between the hot water and the low-pressure steam in the superheater 5, and therefore makes it possible to make the superheater 5 more compact.

[0028] In addition, in such a vapor compression device A1, the heat transfer area of ​​the heat exchange in the superheater 5 is smaller than the heat transfer area of ​​the heat exchange in the exhaust heat recovery heat exchanger 4 (heat recovery section). Here, we will first explain the amount of heat exchanged between the exhaust heat recovery heat exchanger 4 and the superheater 5. For example, the amount of heat exchanged Q1 required to convert low-temperature water (hw=293 kJ / kg) at 70°C to saturated steam (hs=2627 kJ / kg) at 70°C with a flow rate of 0.1 kg / s can be calculated using (Equation 1) to be approximately 233 kW. On the other hand, to convert 70°C saturated steam with a flow rate of 0.1 kg / s at the same pressure into 80°C superheated steam (hv=2646 kJ / kg), a heat exchange amount Q2 of approximately 2 kW is required, which can be calculated using (Equation 2).

[0029] Q1=W×(hs-hw) (Formula 1) Q1: Exchange heat amount (kW) W:Flow rate (kg / s) hs: Specific enthalpy of saturated steam (kJ / kg) hw: specific enthalpy of low-temperature water (kJ / kg) Q2=W×(hv-hs) (Formula 2) Q2: Exchange heat amount (kW) hv: specific enthalpy of superheated steam (kJ / kg) For this reason, the heat transfer area required for the superheater 5 can be made relatively smaller than that required for the exhaust heat recovery heat exchanger 4 .

[0030] According to such a vapor compression device A1, it is possible to achieve a compact superheater 5. This is a more advantageous effect in a configuration in which the superheater 5 is disposed adjacent to the second gas-liquid separator 3 (gas-liquid separation section).

[0031] In addition, in such a vapor compression device A1 (see FIG. 1), the superheater 5 is disposed vertically above the second gas-liquid separator 3 (gas-liquid separation section).

[0032] The superheater 5 requires a sensible heat quantity of the temperature difference required to superheat the saturated low-pressure steam to a predetermined temperature. On the other hand, assuming that drain is accompanied by the low-pressure steam and flows into the superheater 5, the flowing drain also needs to be evaporated and superheated. In this case, in order to supply the low-pressure steam in a superheated state to the compressor 1, in addition to the latent heat required to evaporate the drain, sensible heat is required to superheat the drain steam. Therefore, the superheater 5 of the vapor compression device A1 is enlarged. Also, if the drain cannot be completely evaporated in the superheater 5, the drain may flow into the compressor 1. In contrast, according to the vapor compression device A1, the superheater 5 is located vertically above the second gas-liquid separator 3, so that the drain generated in the pipe 22 is less likely to flow therein.

[0033] In addition, in such a vapor compression device A1 (see FIG. 1), the pipe 22 through which low-pressure steam (gas) flows from the second gas-liquid separator 3 (gas-liquid separation section) to the superheater 5 is shorter than the pipe 13 through which low-pressure steam (gas) flows from the superheater 5 to the compressor 1. According to this vapor compression device A1, even if drainage occurs in the pipe 22, the drainage can return to the second gas-liquid separator 3 by its own weight through the short pipe 22. The inflow of the drainage into the superheater 5 is more reliably prevented.

[0034] In addition, in such a vapor compression unit A1 (see FIG. 1), it is preferable that the superheater 5 is disposed adjacent to the second gas-liquid separator 3 (gas-liquid separation section). According to this vapor compression device A1, the piping 22 can be omitted or the length of the piping 22 can be further shortened, so that the occurrence of drainage between the second gas-liquid separator 3 and the superheater 5 can be more reliably prevented.

[0035] <Second embodiment> Next, a vapor compression device according to a second embodiment of the present invention will be described. 2 is a cycle system diagram showing the configuration of a vapor compression device A2 (gas compression device) according to a second embodiment of the present invention. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0036] As shown in FIG. 2, the vapor compression device A2 includes a pipe 30 that connects the pipe 12 and the pipe 14 together. The pipe 12 corresponds to the "first pipe." The pipe 14 corresponds to the "second pipe." The pipe 14 corresponds to the "second pipe." The pipe 30 corresponds to the "third pipe." That is, the pipe 30 forms a bypass flow path for the hot water (heat medium) that connects the upstream side of the superheater 5 with the downstream side of the superheater 5, with respect to the hot water (heat medium) flow path formed by the pipe 12, the superheater 5, and the pipe 14.

[0037] Further, a hot water flow control valve 31 is provided in the pipe 12 between the connection between the pipe 12 and the pipe 30 and the hot water (heat medium) inlet of the superheater 5. 2, the vapor compression device A2 is provided with a temperature sensor 32 in the pipe 22. This temperature sensor 32 detects a first temperature T1 of the saturated low-pressure steam flowing through the pipe 22, i.e., the first temperature T1 of the low-pressure steam on the inlet side of the superheater 5, and outputs a temperature detection signal. 2, the vapor compression device A2 is provided with a temperature sensor 33 in the pipe 13. This temperature sensor 33 detects a second temperature T2 of the superheated low-pressure steam flowing in the pipe 13, i.e., the second temperature T2 of the low-pressure steam on the outlet side of the superheater 5, and outputs a temperature detection signal.

[0038] As shown in FIG. 2, the vapor compression device A2 includes a control unit . In this embodiment, the control unit 34 adjusts the opening degree of the hot water flow adjustment valve 31 based on the temperature detection signals output by the temperature sensors 32 and 33, respectively. The control unit 34 can be configured to include a ROM (Read Only Memory) that stores a control program for the opening degree of the hot water flow control valve 31, a RAM (Random Access Memory) that reads out and expands the control program stored in the ROM, and a CPU (Central Processing Unit) that executes the expanded control program and outputs a drive command to a valve body drive unit (not shown) of the hot water flow control valve 31.

[0039] FIG. 3 is a flowchart illustrating a procedure in which the control unit 34 (see FIG. 2) outputs a drive command to the hot water flow adjustment valve 31 (see FIG. 2) in accordance with a control program. 3, the control unit 34 reads out the degree of superheat ΔT' stored in the ROM and sets it in the RAM (step S100). This degree of superheat ΔT' is a target value of the temperature difference between the outlet temperature of the low-pressure steam superheater 5 and the inlet temperature of the low-pressure steam superheater 5. This degree of superheat ΔT' corresponds to the "predetermined temperature difference set in advance." Such a degree of superheat ΔT′ is determined in advance as a target value of a degree of superheat necessary and sufficient to prevent drainage from occurring in the pipe 13.

[0040] Next, as shown in Fig. 3, the control unit 34 measures the temperature difference ΔT (T2-T1) based on the temperature detection signals from the temperature sensors 32 and 33 (step S101). That is, the control unit 34 measures the temperature difference ΔT (T2-T1) between the second temperature T2 (see Fig. 2) of the low-pressure steam at the outlet side of the superheater 5 (see Fig. 2) and the first temperature T1 (see Fig. 2) of the low-pressure steam at the inlet side of the superheater 5 (see Fig. 2).

[0041] Next, the control unit 34 judges whether ΔT>ΔT' as shown in Fig. 3 (step S102). If ΔT>ΔT' (Yes in step S102), the control unit 34 outputs a drive command to the hot water flow control valve 31 (see Fig. 2) to reduce the opening (step S103). Then, the process returns to step S101. Furthermore, the hot water flow control valve 31 (see FIG. 2) narrows its opening in response to the drive command in step S103, thereby reducing the flow rate of hot water flowing through the superheater 5 via the pipe 12. Then, the flow rate of hot water flowing through the exhaust heat recovery heat exchanger 4 via the pipe 30 and the pipe 14 increases. As a result, the first temperature T1 (see FIG. 2) of the low-pressure steam on the inlet side of the superheater 5 (see FIG. 2) increases, while the amount of heat applied to the low-pressure steam by the superheater 5 decreases. Therefore, the temperature difference ΔT (T2-T1) decreases.

[0042] If the control unit 34 determines in step S102 that ΔT>ΔT' is not true (No in step S102), the control unit 34 determines whether or not ΔT<ΔT' is true (step S104). If ΔT<ΔT' is true (Yes in step S104), the control unit 34 outputs a drive command to the hot water flow control valve 31 (see FIG. 2) to increase the opening (step S105). Then, the process returns to step S101.

[0043] Furthermore, when the hot water flow control valve 31 (see FIG. 2) is opened in response to the drive command in step S105, the flow rate of hot water flowing through the superheater 5 via the pipe 12 increases. Then, the flow rate of hot water flowing through the exhaust heat recovery heat exchanger 4 via the pipe 30 and the pipe 14 decreases. As a result, the first temperature T1 (see FIG. 2) of the low-pressure steam on the inlet side of the superheater 5 (see FIG. 2) decreases, while the amount of heat applied to the low-pressure steam by the superheater 5 increases. Therefore, the temperature difference ΔT (T2-T1) increases. Moreover, if the control unit 34 determines in step S104 that ΔT<ΔT' is not satisfied (No in step S104), then the process returns to step S101 again.

[0044] Then, by returning to step S101 after each of steps S103, S104, and S105, a series of steps consisting of steps S101, S102, and S103 and a series of steps consisting of steps S101, S102, S104, and S105 are repeated. As a result, the control unit 34 controls the operation of the vapor compression device A2 so that the temperature difference ΔT (T2-T1) becomes the target degree of superheat ΔT'. The vapor compression device A2 is operated so as to send a necessary and sufficient amount of hot water to the superheater 5 so that no drain is generated in the pipe 13.

[0045] <Action and effect> Next, the effects of the vapor compression device A2 (see FIG. 1) of this embodiment will be described. The vapor compression device A2 of this embodiment includes a pipe 12 (first pipe) that supplies hot water (heat medium) to the superheater 5, a pipe 14 (second pipe) that supplies the hot water (heat medium) from the superheater 5 to the exhaust heat recovery heat exchanger 4 (heat recovery section), and a pipe 30 (third pipe) that connects the pipe 12 (first pipe) and the pipe 14 (second pipe).

[0046] According to this vapor compression device A2, only the hot water at a flow rate necessary and sufficient for heating is supplied to the superheater 5, and the remaining hot water can be supplied to the exhaust heat recovery heat exchanger 4 (heat recovery section). In other words, according to the vapor compression device A2, it is possible to cope with the situation without flowing the entire amount of hot water with exhaust heat to the superheater 5. Therefore, according to this vapor compression device A2, it is possible to efficiently reuse the exhaust heat and further reduce the size of the superheater 5.

[0047] Moreover, such a vapor compression device A2 includes a temperature sensor 32 (first temperature detection means) that detects a first temperature T1 at an inlet of the superheater 5 of the low-pressure steam (gas) supplied to the compressor 1 from the second gas-liquid separator 3 (gas-liquid separation section) via the superheater 5, a temperature sensor 33 (second temperature detection means) that detects a second temperature T2 at an outlet of the superheater 5, a hot water flow control valve 31 (flow rate control valve) that adjusts the flow rate of the hot water (heat medium) flowing through the superheater 5, and a control unit 34 that controls the opening degree of the hot water flow control valve 31 (flow rate control valve) so that the difference between the first temperature T1 detected by the temperature sensor 32 (first temperature detection means) and the second temperature T2 detected by the temperature sensor 33 (second temperature detection means) becomes a predetermined temperature difference (degree of superheat ΔT') that has been set in advance.

[0048] According to this vapor compression device A2, the control unit 34 controls the supply of a necessary and sufficient amount of hot water to the superheater 5 so that no drain is generated in the piping 13. This makes it possible to reuse the exhaust heat more efficiently and to more reliably achieve a compact superheater 5.

[0049] Although the first and second embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention. In the first and second embodiments, an open system steam compression device A1, A2 has been described in which low pressure steam is heated and pressurized in a compressor 1 to supply high pressure steam to the user side (outside the system) and consumed water is supplied from the outside (outside the system). However, the gas compression device of the present invention is not limited to an open system, but can also be applied to a closed system such as a heat pump system, in which high-pressure steam obtained by heating and pressurizing low-pressure steam in the compressor 1 is used in the device (system). That is, in this closed system, low-pressure steam is generated again in the second gas-liquid separator 3 based on water condensed by utilizing heat associated with the high-pressure steam in the system, and this low-pressure steam is heated and pressurized again by the compressor 1 via the superheater 5. In addition, the gas to be compressed in the gas compression device of the present invention is not limited to water vapor, and any gas that can be converted into gas-liquid can be used. Among them, the gas to be compressed can be suitably a fluorocarbon-based, hydrocarbon-based, ammonia-based, or other gas that can be used as a refrigerant. [Explanation of symbols]

[0050] 1 Compressor 2 First gas-liquid separator 3 Second gas-liquid separator (gas-liquid separation section) 4 Exhaust heat recovery heat exchanger (heat recovery section) 5 Superheater 6 Feed water heat exchanger 7. Low temperature water circulation pump 8 Supply Pump 9 Flow Regulating Valve 10 Pressure reducing valve 31 Hot water flow control valve (heat medium flow control valve) 32 Temperature sensor (first temperature detection means) 33 Temperature sensor (second temperature detection means) 34 Control section A1 Vapor compression device (gas compression device) A2 Vapor compression equipment (gas compression equipment) T1 1st temperature T2 2nd temperature

Claims

1. a gas-liquid separation unit that evaporates liquid to generate gas and separates the gas and liquid; a heat recovery section that supplies a liquid heated by a heat medium to the gas-liquid separation section; a compressor that compresses the gas supplied from the gas-liquid separation unit; a superheater that heats the gas by heat exchange between the heat medium supplied to the heat recovery unit and the gas supplied from the gas-liquid separation unit to the compressor; Equipped with A gas compression device, characterized in that the heat medium flows through the superheater and the heat recovery section in this order.

2. 2. The gas compression device according to claim 1, wherein the heat recovery unit is a heat exchanger that heats the liquid supplied from the gas-liquid separation unit by heat exchange between the heat medium supplied from the superheater and the liquid supplied from the gas-liquid separation unit.

3. 3. The gas compression device according to claim 2, wherein a heat transfer area of ​​the heat exchange in the superheater is smaller than a heat transfer area of ​​the heat exchange in the heat recovery section.

4. A first pipe that supplies the heat medium to the superheater; A second pipe for supplying a heat medium from the superheater to the heat recovery unit; A third pipe connecting the first pipe and the second pipe; 2. The gas compression device according to claim 1, further comprising:

5. a first temperature detection means for detecting a first temperature of the gas supplied from the gas-liquid separation unit to the compressor through the superheater at an inlet side of the superheater; a second temperature detection means for detecting a second temperature of the gas at an outlet side of the superheater; a heat medium flow control valve that adjusts a flow rate of the heat medium flowing through the superheater; a control unit that controls an opening degree of the heat medium flow control valve so that a difference between a first temperature detected by the first temperature detection means and a second temperature detected by the second temperature detection means becomes a predetermined temperature difference that is set in advance; 5. The gas compression device according to claim 4, further comprising:

6. 2. The gas compression device according to claim 1, wherein the superheater is disposed vertically above the gas-liquid separation section.

7. 7. The gas compression device according to claim 6, wherein a pipe for circulating the gas from the gas-liquid separation unit to the superheater is shorter than a pipe for circulating the gas from the superheater to the compressor.

8. 8. The gas compression device according to claim 7, wherein the superheater is disposed adjacent to the gas-liquid separation section.

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