Desalted water raw water multi-stage heat recovery device

Abstract

The utility model discloses a demineralized water raw water multistage heat recovery device which comprises a condensed water pipeline, a circulating water return pipeline and a raw water pipeline, a raw water thermometer is arranged at the front end of the raw water pipeline, the raw water pipeline and the circulating water return pipeline are jointly connected to a first heat exchanger, the first heat exchanger is connected with a second heat exchanger, and the second heat exchanger is connected with a third heat exchanger. The liquid outlet end of the second heat exchanger is connected with a continuous heat exchange pipeline and a circulating water return drainage pipe through two branches, the continuous heat exchange pipeline and the condensed water pipeline are jointly connected with a third heat exchanger, and the liquid outlet end of the third heat exchanger is connected with a heating raw water pipe and a condensed water return pipe. The utility model has the advantages that the heat efficiency is fully utilized, the energy is saved, and the raw water can be subjected to accurate heat exchange and temperature rise.

Description

Technical Field

[0001] The utility model relates to a device for heating desalted raw water, in particular to a multi-stage heat recovery device for desalted raw water. Background Art

[0002] The raw water for making desalted water is taken from the surface water plant, and the lowest temperature in winter is 0.5℃. If it is used directly, the desalted water system will not be able to operate normally. The existing desalted water system generally requires the raw water temperature to be around 25℃, and the temperature difference is relatively large, so it is difficult for ordinary heat exchange to achieve continuous operation. Therefore, the existing method is to use steam to heat the raw water, which wastes a lot of resources; and the existing petrochemical enterprises will produce a lot of condensed water and circulating water, which will have a lot of waste heat that cannot be fully utilized. We urgently need a set of equipment that can recover the above waste heat and make the raw water meet the requirements to ensure the normal operation of the desalted water system. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a multi-stage heat recovery device for desalted raw water, which can make full use of the waste heat of condensed water and circulating water, and can also perform heat exchange and temperature raising of raw water.

[0004] In order to solve the above technical problems, the utility model provides a multi-stage heat recovery device for desalted raw water, including a condensate water pipeline, a circulating return water pipeline and a raw water pipeline. A raw water thermometer is provided at the front end of the raw water pipeline. Its structural characteristics are: the raw water pipeline and the circulating return water pipeline are commonly connected to a first heat exchanger, the first heat exchanger is connected to a second heat exchanger, the liquid outlet end of the second heat exchanger is respectively connected to a further heat exchange pipeline and a circulating return water drain pipe through two branches, the further heat exchange pipeline and the condensate water pipeline are commonly connected to a third heat exchanger, and the liquid outlet end of the third heat exchanger is connected to a heated raw water pipe and a condensate return pipe.

[0005] A first thermometer is installed on the condensate water pipeline, a first bypass pipe arranged in parallel with the third heat exchanger is connected between the condensate water pipeline and the condensate water return pipe, a second bypass pipe arranged in parallel with the third heat exchanger is connected between the further heat exchange pipeline and the heating raw water pipe, a first electrically-controlled valve capable of detecting water temperature and flow is provided on the first bypass pipe, a second electrically-controlled valve located between the connecting point of the first bypass pipe and the condensate water pipeline and the water inlet pipe of the third heat exchanger is installed on the condensate water pipeline, a third electrically-controlled valve capable of detecting water temperature and flow is connected to the heating raw water pipe, a fourth electrically-controlled valve is provided on the second bypass pipe, and the first electrically-controlled valve, the second electrically-controlled valve, the third electrically-controlled valve and the fourth electrically-controlled valve are all electrically connected to the controller.

[0006] A circulating return water circulation pipe and a raw water circulation pipe are installed between the first heat exchanger and the second heat exchanger, a third bypass pipe arranged in parallel with the first heat exchanger is installed between the raw water pipeline and the raw water circulation pipe, a fourth bypass pipe arranged in parallel with the first heat exchanger is installed between the circulating return water pipeline and the circulating return water circulation pipe, and valves are provided on the third bypass pipe and the fourth bypass pipe.

[0007] A fifth bypass pipe arranged in parallel with the second heat exchanger is installed between the fourth bypass pipe and the circulating return water drainage pipe, and a sixth bypass pipe arranged in parallel with the second heat exchanger is installed between the third bypass pipe and the continuing heat exchange pipeline. Valves are provided on the fifth bypass pipe and the sixth bypass pipe.

[0008] After adopting the above structure, raw water enters from the raw water pipeline, and is fully heat exchanged with the circulating return water in the circulating return water pipeline through the first heat exchanger and the second heat exchanger, and then the raw water is fully heat exchanged with the condensed water through the third heat exchanger. It can be seen from the above use process of the utility model that the utility model fully utilizes the characteristics of the circulating return water and the condensed water. The temperature of the circulating return water is a little lower than that of the condensed water, so the raw water is gradually heat exchanged from low to high temperature, which not only improves the heat exchange efficiency, but also ensures the full exchange of heat, so that the residual heat of the condensed water and the circulating water can be fully utilized, and the raw water can be accurately heat exchanged and heated, thereby achieving the purpose of saving energy.

[0009] In summary, the utility model has the advantages of full utilization of thermal efficiency, energy saving and accurate heat exchange and temperature raising of raw water. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The utility model is further described below in conjunction with the accompanying drawings:

[0011] Figure 1 This is a schematic diagram of the structure of an embodiment of the utility model;

[0012] Figure 2 for Figure 1 A schematic structural diagram of an embodiment of a heat exchanger. DETAILED DESCRIPTION

[0013] The utility model provides a multi-stage heat recovery device for desalted raw water. For the convenience of description, the front-to-back direction in this embodiment refers to the flow direction of the fluid, and the fluid flows backward. In addition, the connection of the following pipelines can be understood as a direct connection, or as an indirect connection through structures such as flanges and pipe joints. The specific structure and sealing issues of the various pipeline connections are all existing technologies and will not be introduced in detail here.

[0014] refer to Figure 1As shown, the utility model provides an optimal embodiment, which includes a condensate water pipeline 1, a circulating return water pipeline 2 and a raw water pipeline 3, a raw water thermometer 4 is provided at the front end of the raw water pipeline 3, the raw water pipeline 3 and the circulating return water pipeline 2 are commonly connected to a first heat exchanger 5, the first heat exchanger 5 is connected to a second heat exchanger 6, the liquid outlet end of the second heat exchanger 6 is respectively connected to a further heat exchange pipeline 7 and a circulating return water drain pipe 8 through two branches, the further heat exchange pipeline 7 and the condensate water pipeline 1 are commonly connected to a third heat exchanger 9, the liquid outlet end of the third heat exchanger 9 is connected to a heated raw water pipe 10 and a condensate return pipe 11.

[0015] refer to Figure 1 As shown, the condensate water pipeline 1 is provided with a first thermometer 12, and a first bypass pipe 13 arranged in parallel with the third heat exchanger 9 is also connected between the condensate water pipeline 1 and the condensate water return pipe 11, and a second bypass pipe 14 arranged in parallel with the third heat exchanger is also connected between the continuous heat exchange pipeline 7 and the heating raw water pipe 10, and a first electrically-controlled valve 15 capable of detecting water temperature and flow is provided on the first bypass pipe 13, and a second electrically-controlled valve 16 located between the connection point between the first bypass pipe 13 and the condensate water pipeline 1 and the water inlet pipe of the third heat exchanger 9 is provided on the condensate water pipeline 1, a third electrically-controlled valve 17 capable of detecting water temperature and flow is connected to the heating raw water pipe 10, and a fourth electrically-controlled valve 18 is provided on the second bypass pipe 14, and the first electrically-controlled valve 15, the second electrically-controlled valve 16, the third electrically-controlled valve 17 and the fourth electrically-controlled valve 18 are all electrically connected to the controller 19. The above-mentioned four electrically controlled valves are opened and closed by manipulating the controller 19, so that the flow direction of the liquid can be controlled. For example, when the first electrically controlled valve 15 is closed, the fourth electrically controlled valve 18 is also closed, and the raw water and condensate are fully heat exchanged in the third heat exchanger. At this time, the purpose of control is that the heating temperature of the raw water is not enough. By detecting the water temperature and flow rate and controlling the above-mentioned electrically controlled valves, it is possible to determine whether the raw water is heat exchanged through the third heat exchanger 9 to ensure that the heating temperature of the raw water is appropriate and resources are not wasted.

[0016] refer to Figure 1As shown, a circulating return water circulation pipe 21 and a raw water circulation pipe 22 are installed between the first heat exchanger 5 and the second heat exchanger 6, a third bypass pipe 23 is installed between the raw water pipeline 3 and the raw water circulation pipe 22, and is connected in parallel with the first heat exchanger 5. A fourth bypass pipe 24 is installed between the circulating return water pipeline 2 and the circulating return water circulation pipe 21, and is connected in parallel with the first heat exchanger 5. Valves are provided on the third bypass pipe 23 and the fourth bypass pipe 24. A fifth bypass pipe 25 is installed between the fourth bypass pipe 24 and the circulating return water drainage pipe 8, and is connected in parallel with the second heat exchanger 6. A sixth bypass pipe 26 is installed between the third bypass pipe 23 and the continuous heat exchange pipeline 7, and is connected in parallel with the second heat exchanger 6. Valves are provided on the fifth bypass pipe 25 and the sixth bypass pipe 26. The purpose of setting the third bypass pipe 23, the fourth bypass pipe 24, the fifth bypass pipe 25 and the sixth bypass pipe 26 is the same as that of the first bypass pipe 13 and the second bypass pipe 14, which can control whether the raw water and the circulating return water pass through the first heat exchanger and the second heat exchanger for heat exchange, and the control process will not be discussed in detail here.

[0017] refer to Figure 1 and Figure 2 As shown, the figure schematically shows a heat exchanger. The above-mentioned first heat exchanger, second heat exchanger and other heat exchangers can all adopt the heat exchanger structure in the figure. Its basic structure includes an outer shell, and four pipe joints are installed on the outer shell. A heat exchange pipeline is also installed in the outer shell. The heat exchange pipeline can be set in a U shape as shown in the figure, or in other shapes, where two pipe joints are connected to the above-mentioned heat exchange pipeline, and the other two pipe joints are connected to the inner cavity in the outer shell. The above-mentioned raw water, circulating return water and condensed water can go through the tube side (inside the heat exchange pipeline) and the shell side (inner cavity of the outer shell), respectively, and their specific requirements will not be discussed here. Of course, heat exchangers with other structures on the market can also be used, and heat exchangers with other structures are not described.

[0018] The present invention is not limited by the above-mentioned embodiments. For those skilled in the art, equivalent changes and component replacements based on the specific structure of the present invention are all within the protection scope of the present invention.

Claims

1. A multi-stage heat recovery device for desalted raw water, comprising a condensate pipeline, a circulating return water pipeline and a raw water pipeline, wherein a raw water thermometer is provided at the front end of the raw water pipeline, and wherein: The raw water pipeline and the circulating return water pipeline are commonly connected to the first heat exchanger, the first heat exchanger is connected to the second heat exchanger, the liquid outlet end of the second heat exchanger is connected to the further heat exchange pipeline and the circulating return water drain pipe through two branches respectively, the further heat exchange pipeline and the condensate water pipeline are commonly connected to the third heat exchanger, and the liquid outlet end of the third heat exchanger is connected to the heated raw water pipe and the condensate water return pipe.

2. The multi-stage heat recovery device for desalted raw water according to claim 1 is characterized in that: A first thermometer is installed on the condensate water pipeline, a first bypass pipe arranged in parallel with the third heat exchanger is connected between the condensate water pipeline and the condensate water return pipe, a second bypass pipe arranged in parallel with the third heat exchanger is connected between the further heat exchange pipeline and the heating raw water pipe, a first electrically-controlled valve capable of detecting water temperature and flow is provided on the first bypass pipe, a second electrically-controlled valve located between the connecting point of the first bypass pipe and the condensate water pipeline and the water inlet pipe of the third heat exchanger is installed on the condensate water pipeline, a third electrically-controlled valve capable of detecting water temperature and flow is connected to the heating raw water pipe, a fourth electrically-controlled valve is provided on the second bypass pipe, and the first electrically-controlled valve, the second electrically-controlled valve, the third electrically-controlled valve and the fourth electrically-controlled valve are all electrically connected to the controller.

3. The multi-stage heat recovery device for desalted raw water according to claim 1 is characterized in that: A circulating return water circulation pipe and a raw water circulation pipe are installed between the first heat exchanger and the second heat exchanger, a third bypass pipe arranged in parallel with the first heat exchanger is installed between the raw water pipeline and the raw water circulation pipe, a fourth bypass pipe arranged in parallel with the first heat exchanger is installed between the circulating return water pipeline and the circulating return water circulation pipe, and valves are provided on the third bypass pipe and the fourth bypass pipe.

4. The multi-stage heat recovery device for desalted raw water according to claim 3 is characterized in that: A fifth bypass pipe arranged in parallel with the second heat exchanger is installed between the fourth bypass pipe and the circulating return water drainage pipe, and a sixth bypass pipe arranged in parallel with the second heat exchanger is installed between the third bypass pipe and the continuing heat exchange pipeline. Valves are provided on the fifth bypass pipe and the sixth bypass pipe.

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