Seawater source heat pump system utilizing waste cold and waste heat and control method

Abstract

The invention belongs to the technical field related to energy, and particularly relates to a seawater source heat pump system utilizing waste cold and waste heat and a control method. By dynamically allocating waste cold of an LNG station, waste heat of a thermal power plant and cold and hot resources of seawater, the energy utilization requirements of a condenser and a gasifier are preferentially guaranteed, the power generation efficiency of the thermal power plant is improved, and the disposable energy consumption of LNG is reduced; and when residual cold or residual heat is insufficient, a seawater source is started for cold or heat supplement, continuous stability and supply and demand balance in the energy supply process are ensured, the system adaptability is high, and the operation reliability is high.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energy, and particularly relates to a seawater source heat pump system utilizing residual cold and heat and a control method. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] During the operation of an LNG station and a thermal power plant, a large amount of residual cold and heat resources will be generated, respectively. The residual cold generated in the LNG gasification process and the residual heat discharged from the steam turbine of the thermal power plant can be reasonably recovered by a recovery device, which can replace the traditional energy-driven refrigeration and heating mode, reduce energy waste and carbon emissions, and has a very wide application field and great value.

[0004] At present, the residual cold of the LNG station and the residual heat of the thermal power plant have been widely used due to high efficiency and energy saving. However, in actual operation, the load fluctuation of the LNG station and the thermal power plant will cause the generation of residual cold and heat to fluctuate. In addition, with the change of time period, the cold and heat load demand of users will also change, which restricts the comprehensive level of recovery and utilization of the residual cold of the LNG station and the residual heat of the thermal power plant.

[0005] Therefore, it is an urgent problem to be solved to realize the precise matching and efficient collaborative utilization of the residual cold of the LNG station and the residual heat of the thermal power plant and the cold and heat demand of users, ensure the stable and efficient operation of the whole system, and promote the energy cascade utilization of the LNG station and the thermal power plant. SUMMARY

[0006] In order to overcome the above-mentioned deficiencies of the prior art, the present application provides a seawater source heat pump system utilizing residual cold and heat, which converts the energy that may be discarded or discharged into stable and reliable cold and heat sources, and realizes efficient and cyclic utilization of energy.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions: In a first aspect, the present application provides a seawater source heat pump system utilizing residual cold and heat, comprising: a gasifier, a steam turbine, a condenser and a heat exchanger. The gasifier is used to convert liquefied natural gas into gaseous natural gas and output cold energy, and provide cold energy for summer seawater source heat pump refrigeration and the condenser. The steam turbine is connected with the condenser through a pipeline and serves as a main heat source in winter heating mode. The condenser is connected with the heat exchanger and the heat pump unit through a circulating pipeline, and is used to recover the steam turbine exhaust heat and convert it into a heat medium fluid. The heat exchanger is connected with the gasifier or the condenser on one side, and is connected with a seawater source and the heat pump unit on the other side, and functions as an exchanger of LNG waste heat and seawater cold source in summer and as an enhancer of condenser waste heat and seawater heat in winter.

[0008] In a second aspect, the application provides a control method of a seawater source heat pump system utilizing waste heat and waste cold, comprising: judging whether the waste heat of the exhaust of the steam turbine meets the heat load required by the user and the gasification of the liquefied natural gas; if yes, switching the valve to deliver the waste heat of the thermal power plant to the gasifier as a gasification heat source, and simultaneously delivering the waste heat to the circulating water through the heat exchanger, and delivering the circulating water to the user side after the circulating water passes through the heat pump unit; if no, dynamically adjusting the opening degree of the valve, preferentially supplying heat to the gasifier, and starting the seawater source heat pump to extract heat from seawater to make up for the gap of the heat load in cooperation with the remaining waste heat.

[0009] In a third aspect, the application provides a control method of a seawater source heat pump system utilizing waste heat and waste cold, comprising: judging whether the cold energy generated by the gasification of the liquefied natural gas meets the cold load required by the condenser of the thermal power plant and the user; if yes, delivering the cold energy generated by the gasification of the liquefied natural gas to the condenser through the valve control, and simultaneously delivering the cold energy to the circulating refrigerant through the heat exchanger, and delivering the cold energy to the heat pump unit through the circulating refrigerant to provide refrigeration services for the user side; if no, preferentially supplying cold to the condenser of the thermal power plant by dynamically adjusting the opening degree of the valve, and opening the seawater delivery pump to extract low-temperature seawater to supplement the circulating refrigerant to meet the refrigeration demand of the user side.

[0010] The above one or more technical solutions have the following beneficial effects: In the application, the cold and heat resources of the LNG station waste cold, the waste heat of the thermal power plant and seawater are dynamically allocated, the energy demand of the condenser and the gasifier is preferentially guaranteed, the power generation efficiency of the thermal power plant is improved, the primary energy consumption of the LNG is reduced, and the seawater source is used to supplement cold or heat when the waste cold or waste heat is insufficient, so that the continuity and stability of energy supply are ensured, the adaptability of the system is high, and the operation reliability is high.

[0011] In the application, the seawater is used as a "natural energy battery" and the final guarantee of the system, and when the cold or heat is insufficient, the seawater source heat pump technology is used to extract cold or heat from seawater for supplement, so that the continuity and stability of energy supply are ensured, and the environmental benefits are outstanding.

[0012] In the application, a large amount of residual cold generated in the LNG gasification process, residual heat discharged by the steam turbine of the thermal power plant and the huge seawater resource are integrated in a set of system, and through system design and control strategy, the energy which can be discarded or discharged is converted into stable and reliable cold source and heat source, so that the efficient and cyclic utilization of energy is realized.

[0013] Advantages of the additional aspects of the application will be partially given in the following description, partially will become obvious from the following description, or will be understood by the practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0014] The accompanying drawings, which form a part of the specification, are included to provide a further understanding of the application and are incorporated herein for explanation by referring to the exemplary embodiments thereof.

[0015] Figure 1 A seawater source heat pump system block diagram in the first embodiment of the application; Figure 2 A seawater source heat pump system control flow chart in the first embodiment of the application. DETAILED DESCRIPTION

[0016] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0017] It should be noted that the terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the application.

[0018] In the case of no conflict, the embodiments in the application and the features in the embodiments can be combined with each other.

[0019] Embodiment one The embodiment discloses a seawater source heat pump system using residual cold and heat, comprising a gasifier, a steam turbine, a condenser and a heat exchanger. The gasifier is one of the core devices of the liquefied natural gas station, which is connected with the LNG storage unit and the heat exchanger through the pipeline, and can convert the liquefied natural gas into gaseous natural gas. In this process, the demand for natural gas supply is met, and a large amount of cold energy is output for the seawater source heat pump system. It is the core cold source for the seawater source heat pump system to provide cold energy for seawater source heat pump refrigeration in summer and condenser of the thermal power plant. The steam turbine is the energy conversion core of the thermal power plant, and the exhaust end is connected with the condenser through the pipeline. It is the stable and main heat source of the seawater source heat pump system in the winter heating mode, and is the core heat source of the seawater source heat pump system on the heating side, realizing the recovery and utilization of the residual heat of the thermal power plant.

[0020] Condenser is the condensing equipment of steam turbine exhaust, and also the waste heat collection device of seawater source heat pump system. It is connected with heat exchanger and heat pump unit through circulating pipeline to convert the exhaust steam waste heat of steam turbine into usable heat medium fluid, and complete the recovery of waste heat of thermal power plant.

[0021] Heat exchanger is the key hub of seawater source heat pump system to realize the energy exchange between waste heat, waste cold and seawater. One side pipeline is connected with gasifier or condenser, and the other side pipeline is connected with seawater source and heat pump unit. In summer refrigeration mode, heat exchanger is the cold exchange device between liquefied natural gas waste cold and seawater; in winter heating mode, it is the heat enhancer between condenser waste heat and seawater, which ensures the efficient and stable energy exchange of seawater source heat pump system.

[0022] As an optional implementation, heat exchanger can use PPR or PERT material heat exchanger, which has the characteristics of resisting seawater corrosion.

[0023] As a specific implementation, the medium outlet pipeline of liquid natural gas storage unit is directly connected with the medium inlet of gasifier, and the medium outlet end of gasifier is connected with natural gas pipeline (NG pipeline) to realize the conversion of liquid natural gas to gaseous natural gas. Temperature sensor T1 and mass flow meter m1 are installed on the cold energy output pipeline of gasifier, and temperature sensor T1 is installed on the cold energy inlet and outlet pipeline of gasifier to monitor the medium temperature and flow of LNG gasification process in real time.

[0024] The cold energy output end of gasifier is connected with the cold energy input end of second heat exchanger 2 through the pipeline where temperature sensor T1 and valve 1 are located; the cold energy output end of gasifier is also connected with the cold energy input end of condenser through the pipeline where temperature sensor T1, valve 26, valve 10 and temperature sensor T3 are located; to realize the cold exchange between waste cold and circulating refrigerant or seawater.

[0025] As a specific implementation, the main steam pipeline is connected with the steam input end of steam turbine, the exhaust end pipeline of steam turbine is connected with the steam inlet of condenser, and the steam turbine transports the waste heat steam to condenser after completing the conversion of mechanical energy and electric energy. The condensate outlet of condenser is connected with the dedicated condensate pipeline to complete the water circulation on the side of thermal power plant.

[0026] Temperature sensor T3 is installed on the waste heat input pipeline of condenser, and temperature sensor T4 and mass flow meter m2 are installed on the waste heat output pipeline of condenser to monitor the medium parameters of waste heat recovery process.

[0027] The waste heat output end of the condenser is connected to the input end of the vaporizer through the pipeline containing temperature sensor T4, valve 11, and valve 9. The waste heat output end of the condenser is also connected to the heat input end of the first heat exchanger 1 through the pipeline containing temperature sensor T4 and valve 13, thereby realizing the integration of waste heat with the heat of the circulating heat medium or seawater.

[0028] In one specific implementation, the heat exchanger includes a first heat exchanger 1 and a second heat exchanger 2. The heat medium output end of the first heat exchanger 1 is connected to the heat medium input end of the evaporator through the pipelines containing valves 7 and 18. The heat medium return end of the evaporator is connected back to the heat medium inlet end of the first heat exchanger 1 through the pipelines containing valves 20 and 8, forming a heat medium circulation on the heating side. The refrigerant output end of the second heat exchanger 2 is connected to the refrigerant input end of the condenser through the pipelines containing valves 5 and 16. The refrigerant return end of the condenser is connected back to the refrigerant inlet end of the second heat exchanger through the pipelines containing valves 22 and 8, forming a refrigerant circulation on the cooling side. The evaporator and condenser form a closed loop through the refrigerant pipeline, constituting the core heat exchange unit of the seawater source heat pump unit, realizing the phase change of the refrigerant.

[0029] The outlet of the first water pump 1 is connected to the seawater input end of the first heat exchanger 1 through the pipeline where valve 25 and valve 13 are located. The seawater side of the first heat exchanger 1 is connected to the heat pump unit side, so that the heat of the seawater can be introduced into the heat pump unit when the waste heat is insufficient. The outlet of the second water pump 2 is connected to the second heat exchanger 2 through the pipeline where valve 24 is located. The seawater side of the second heat exchanger 2 is connected to the heat pump unit side, so that the cooling capacity of the seawater can be introduced into the heat pump unit when the residual cooling is insufficient.

[0030] In one specific implementation, the low-temperature water output end of the condenser is connected to the user-side cooling water supply port through the pipeline where valve 23 is located, and the user-side cooling water return port is connected back to the condenser's return water input end through the pipeline where valve 17 is located, forming a cooling water circulation; the high-temperature water output end of the evaporator is connected to the user-side heating water supply port through the pipeline where valve 21 is located, and the user-side heating water return port is connected back to the evaporator's return water input end through the pipeline where valve 19 is located, forming a hot water circulation.

[0031] Based on the waste cooling and waste heat conditions of the LNG station and the thermal power plant, as well as the users' heating and cooling load requirements, two operating modes are set up: waste heat heating (including seawater supplemental heating) and waste cooling (including seawater supplemental cooling).

[0032] The waste heat supply mode (including seawater heat supplement) is that the system controller determines whether the exhaust heat of the steam turbine can meet the heat load required by the user and LNG gasification through data calculation of the temperature sensor and the mass flow meter. If yes, the control system switches the valve to enter the waste heat supply mode, that is, the waste heat generated by the thermal power plant is transported to the gasifier through the pipeline as the gasification heat source; at the same time, the heat is transferred to the circulating water through the heat exchanger, and the circulating water is transported to the indoor heat dissipation device after the heat is improved by the heat pump unit to meet the heat load demand of the user. If no, the valve opening is dynamically adjusted to preferentially supply heat to the gasifier, and the excess waste heat is supplied in cooperation with seawater. On the basis of utilizing the waste heat, the seawater source heat pump is started to extract heat from seawater to make up for the load gap.

[0033] The waste cold refrigeration mode (including seawater cold supplement) is to determine whether the cold energy generated by LNG gasification can meet the cold load required by the condenser of the thermal power plant and the building user. If yes, the waste cold refrigeration mode is entered through valve control, that is, the cold energy of LNG is transported to the condenser through the pipeline, and is transported to the circulating refrigerant through the heat exchanger to provide refrigeration service for the indoor and meet the cold load demand of the building user. If no, the waste cold refrigeration + seawater cold supplement mode is entered, and the valve opening is dynamically adjusted to preferentially supply cold to the condenser of the thermal power plant, and the excess waste cold is supplied in cooperation with seawater. While utilizing the waste cold for refrigeration, the seawater delivery pump is opened to extract low-temperature seawater to extract cold energy from seawater to supplement the circulating refrigerant to meet the building refrigeration demand.

[0034] In the refrigeration season, when the LNG station waste cold supply is sufficient, the system can stably output cold energy to meet the condenser heat release of the thermal power plant and the building refrigeration demand. When the LNG station waste cold is insufficient, the waste cold is preferentially supplied to the condenser of the thermal power plant to improve the power generation efficiency, and the heat exchanger is coupled with seawater to extract cold energy for the seawater source heat pump unit to provide cold energy for the building user, thereby guaranteeing the continuous stability and reasonable energy utilization of the refrigeration process. In the heating season, when the waste heat supply of the thermal power plant is sufficient, the system can stably output heat to guarantee the gasification of the gasifier and the heating demand of the building user. If the waste heat supply is insufficient, the waste heat is preferentially supplied to the gasifier to reduce the supply amount of LNG primary energy (such as fuel gas), and the heat exchanger is coupled with seawater to extract heat for the seawater source heat pump unit to provide heat for the building user, thereby realizing efficient load adaptation and stable and reliable operation of the heating process.

[0035] Embodiment Two The purpose of the embodiment is to provide a control method of a seawater source heat pump system utilizing waste cold and waste heat, comprising: determining whether the exhaust heat of the steam turbine can meet the heat load required by the user and LNG gasification; If satisfied, switch the valve to deliver the waste heat of the thermal power plant to the gasifier as the gasification heat source, and at the same time, transfer to the circulating water through the heat exchanger, and the circulating water is delivered to the user side after passing through the heat pump unit; If not satisfied, dynamically adjust the valve opening, preferentially supply heat to the gasifier, and start the seawater source heat pump to extract heat from seawater to make up for the gap in heat load with the remaining waste heat.

[0036] It also includes judging whether the cold energy generated by liquefied natural gas gasification meets the cooling load required by the condenser of the thermal power plant and the user; If satisfied, deliver the cold energy generated by liquefied natural gas gasification to the condenser through valve control, and at the same time, transfer to the circulating refrigerant through the heat exchanger, and then deliver the cold energy to the heat pump unit through the circulating refrigerant to provide refrigeration services for the user side; If not satisfied, dynamically adjust the valve opening, preferentially supply cold to the condenser of the thermal power plant, open the seawater delivery pump to extract low-temperature seawater, and supplement to the circulating refrigerant to meet the refrigeration demand of the user side As shown in Figure 2 The seawater source heat pump heat supply and refrigeration control method using residual cold and heat is as follows: (1) Summer refrigeration mode: First step: system controller initialization, all valves and pumps are in standby state; real-time monitoring of outdoor environment temperature T w , turbine operating power P , LNG gasifier inlet and outlet flow m 1 and inlet and outlet temperature T 1, T 2, valve opening K v1 . Second step: calculate building cooling load Q 0= f 1( T w ) α，α is a constant, determined according to experiments.

[0037] Third step: calculate condenser cold consumption Q 1= f 2( P )× k 冷 + β，β is a constant, determined according to experiments.

[0038] Fourth step: calculate the actual residual cold generated by LNG gasification according to the gasifier inlet and outlet flow m 1 and temperature T 1, T 2 Q 2= cm1 T 1 T 2)。

[0039] Fifth step: calculating the valve opening K v1 = f v ( G 1)+ k 1, wherein, ; k 1 is the basic opening offset, determined by experiment.

[0040] Sixth step: according to the building cooling load Q 0, the condenser cooling consumption Q 1, the cold generated by LNG gasification Q 2 and the valve opening K v1 , when , (wherein, θ >1 needs to be determined according to the water source heat pump unit EER , and in the embodiment θ =1.1), it is the excess cooling sufficient mode, the cold is provided to the condenser through the regulation valve, and the cold is supplied to the heat exchanger for heat exchange, the low-temperature medium enters the condenser, and the refrigerant undergoes a condensation process and releases heat, and the low-temperature medium is heated after absorbing heat and then returns to the heat exchanger to participate in the cycle, completing the heat transfer and discharge; at the same time, the return water of the user side enters the evaporator, and the refrigerant in the evaporator absorbs the heat of the return water through the evaporation process, so that the temperature of the return water is reduced, and finally the low-temperature water is supplied to the user end to meet the refrigeration demand.

[0041] Specifically, the regulation valves 1, 3, 5, 6, 16, 19, 21 and 22 supply cold to the building users to meet the refrigeration demand, and the regulation valves 10 and 26 supply cold to the condenser to meet the heat release of the condenser of the thermal power plant, and the water pumps 1 and 2 and other valves are in the closed state. When , it is the excess cooling insufficient mode, according to K v1 adjust the valve opening, preferentially supply the cold to the condenser, extract the seawater cold through the control valve and the corresponding water pump, and supply the cold to the user through the heat exchanger and the heat pump unit.

[0042] Specifically, according to K v1 the regulation valves 10 and 26 preferentially supply the excess cold to the condenser of the thermal power plant; the water pump 2 is started, the cold is extracted from the seawater, and the excess excess cold and the seawater are cooperated through the control valves 1, 2, 3, 4, 5, 6, 16, 19, 21, 22 and 24 to supply cold to the building users. The water pump 1 and other valves are in the closed state.

[0043] (II) Winter Heating Mode: Step 1: Real-time monitoring of outdoor ambient temperature T w Actual flow rate of LNG M Condenser inlet and outlet flow rates m 2 and inlet / outlet temperatures T 3, T 4. Valve opening degree K v2 . Step 2: Based on the outdoor temperature T w Calculate the building's heat load Q 3= f 1( T w )+ γ, γ It is a constant, determined experimentally.

[0044] Step 3: Based on the actual LNG flow rate M Calculate the heat required for the vaporizer. Q 4= f 3( M )× k 热 + δ, in, k 热 The heat of vaporization coefficient, δ It is a constant, determined experimentally.

[0045] Step 4: Based on the condenser inlet and outlet flow rates m 2 and temperature T 3, T 4. Calculate the actual waste heat. Q 5= cm 2( T 4 T 3).

[0046] Step 5: Calculate the valve opening. K v2 = f v ( G 2)+ k 2, of which, , k 2 is the basic opening offset, which is determined experimentally.

[0047] Step 6: Based on the building's required heat load Q 3. Heat load required for the vaporizer Q 4. Actual waste heat of the condenser Q 5 and valve opening Kv2 When ( ε <1According to the experimental seawater source heat pump unit COP Determination, in this embodiment ε =0.9), it is a waste heat sufficient mode, and the corresponding valves are regulated to supply waste heat to the gasifier and make the waste heat enter the heat exchanger to exchange heat. The high-temperature medium after heat exchange passes through the pipeline to the evaporator, the refrigerant in the evaporator evaporates and absorbs heat to make the high-temperature medium into low-temperature medium, and returns to the heat exchanger to participate in the cycle. The building user return water enters the condensing side, the refrigerant condenses and releases heat, and the temperature of the low-temperature return water rises to supply heat to the building user. Specifically, the valves 7, 8, 13, 14, 17, 18, 20 and 23 are regulated to supply heat to the building user, the valves 9 and 11 are regulated to supply heat to the gasifier, and the water pumps 1 and 2 and other valves are in the closed state.

[0048] When , it is a waste heat insufficient mode, and according to K v2 The valve opening degree is regulated, the waste heat is preferentially supplied to the gasifier, and the corresponding water pump and valve are started to extract heat from seawater to supply heat to the user. Specifically, according to K v2 The valves 9 and 11 are regulated, the waste heat is preferentially supplied to the gasifier to meet the LNG gasification, the water pump 1 is started to extract heat from seawater, the valves 7, 8, 12, 13, 14, 15, 17, 18, 20, 23 and 25 are regulated to realize that the excess waste heat and seawater cooperate to supply heat to the building user, and the water pump 2 and other valves are in the closed state.

[0049] In more embodiments, there are also provided: An electronic device includes a memory and a processor, and computer instructions stored on the memory and running on the processor, when the computer instructions are run by the processor, the method described in embodiment one is completed. For brevity, it will not be repeated here.

[0050] It should be understood that in the embodiments, the processor can be a central processing unit CPU, and the processor can also be other general-purpose processors, digital signal processors DSPs, application-specific integrated circuits ASICs, ready-to-program gate arrays FPGA or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0051] The memory can include read-only memory and random access memory, and provide instructions and data to the processor, and a part of the memory can also include non-volatile random access memory. For example, the memory can also store device type information.

[0052] A computer readable storage medium storing computer instructions, which, when executed by a processor, complete the method described in Embodiment One.

[0053] The method in Embodiment One can be directly embodied as a hardware processor to complete, or be completed by a combination of hardware and software modules in the processor. The software modules can be located in storage media such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, register, or other mature storage media in the field. The storage medium is located in the storage, and the processor reads information in the storage to complete the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.

[0054] A computer program product comprising a computer program, which, when executed by a processor, implements the method described in Embodiment One.

[0055] The present application also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer executable instructions, for example, instructions embodied in program modules, executed by devices at the target real or virtual processor to perform processes / methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functions of program modules can be combined or divided as desired in various embodiments. Machine executable instructions for program modules can be executed within a local or distributed device. In a distributed device, program modules can be located in local and remote storage media.

[0056] Computer program code for carrying out operations of the present application can be written in one or more programming languages. These computer program codes can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, so that the program codes cause the functions / operations specified in the flowcharts and / or block diagrams to be performed when the computer or other programmable data processing apparatus executes the program codes. The program codes can be executed entirely on the computer, partially on the computer, as a standalone software package, partially on the computer and partially on a remote computer, or entirely on a remote computer or server.

[0057] In the context of the present application, computer program code or related data can be carried by any suitable carrier to enable the device, apparatus or processor to perform the various processes and operations described above. Examples of carriers include signals, computer readable media, and the like. Examples of signals can include electrical, optical, radio, sound or other forms of propagated signals, such as carrier waves, infrared signals, and the like.

[0058] Those skilled in the art can understand that the units and algorithm steps of each example described in combination with the present embodiment can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software manner depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0059] Although the specific embodiments of the present application are described above in combination with the drawings, it is not a limitation on the scope of protection of the present application. Those skilled in the art should understand that various modifications or variations made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the scope of protection of the present application.

Claims

1. A seawater source heat pump system utilizing residual cold and heat, characterized by, Comprise: Gasifier, steam turbine, condenser, heat exchanger; The gasifier is used for converting liquefied natural gas into gaseous natural gas and outputting cold energy, providing cold energy for summer seawater source heat pump refrigeration and the condenser; The steam turbine is connected with the condenser through a pipeline and serves as a main heat source in winter heating mode; The condenser is connected with the heat exchanger and the heat pump unit through a circulating pipeline and is used for recycling waste heat of the steam turbine and converting it into heat medium fluid; One side pipeline of the heat exchanger is connected with the gasifier or the condenser, and the other side pipeline is connected with seawater source and the heat pump unit, which serves as an exchanger of liquefied natural gas waste cold and seawater cold source in summer and as an enhancer of condenser waste heat and seawater heat in winter.

2. The sea water source heat pump system utilizing residual cold and heat according to claim 1, characterized in that, The cold energy output end of the gasifier is connected with the heat exchanger and the condenser through pipelines respectively; the waste heat output end of the condenser is connected with the input end of the gasifier and the heat exchanger through pipelines respectively.

3. The sea water source heat pump system utilizing residual cold and heat according to claim 1, characterized in that, The heat pump unit comprises a condenser and an evaporator; the condenser and the evaporator form a cycle through a refrigerant pipeline.

4. The sea water source heat pump system utilizing residual cold and heat according to claim 3, characterized in that, The heat exchanger comprises a first heat exchanger and a second heat exchanger; the heat medium output end of the first heat exchanger is connected with the heat medium input end of the evaporator, the heat medium return end of the evaporator is connected back to the heat medium inlet end of the first heat exchanger, forming a heat supply side heat medium cycle; the cold medium output end of the second heat exchanger is connected with the cold medium input end of the condenser, and the cold medium return end of the condenser is connected back to the cold medium inlet end of the second heat exchanger, forming a refrigeration side cold medium cycle.

5. The sea water source heat pump system utilizing residual cold and heat according to claim 1, characterized in that, The heat exchanger comprises a first heat exchanger and a second heat exchanger; the water outlet of the first water pump is connected with the seawater input end of the first heat exchanger, and the seawater side of the first heat exchanger is communicated with the heat pump unit side, so as to guide seawater heat into the heat pump unit when waste heat is insufficient; The water outlet of the second water pump is connected with the second heat exchanger, and the seawater side of the second heat exchanger is communicated with the heat pump unit side, so as to guide seawater cold into the heat pump unit when waste cold is insufficient.

6. The sea water source heat pump system utilizing residual cold and heat according to claim 3 or 4, characterized in that, The low-temperature water output end of the condenser is communicated with the user side refrigeration water supply end, and the user side refrigeration return water end is connected back to the return water input end of the condenser, forming a refrigeration water cycle; the high-temperature water output end of the evaporator is communicated with the user side heat supply water supply end, and the user side heat return water end is connected back to the return water input end of the evaporator, forming a heat supply water cycle.

7. The sea water source heat pump system utilizing residual cold and heat according to any one of claims 1-6, characterized in that, Further comprising temperature sensors, mass flow meters and valves; the temperature sensors and mass flow meters are respectively used for monitoring temperature and flow data of the medium, and the valves are used for regulating and controlling the conveying path of the medium.

8. The sea water source heat pump system utilizing residual cold and heat according to claim 1, characterized in that, The steam input end of the steam turbine is connected with main steam, and the exhaust end of the steam turbine is connected with the steam inlet of the condenser; after completing mechanical energy and electric energy conversion, the steam turbine delivers waste heat steam to the condenser; the condensate water outlet of the condenser is connected with a condensate water pipeline for backflow, completing water circulation on the thermal power plant side.

9. A control method of a seawater source heat pump system using surplus cold and heat, characterized by, Comprise: Judging whether the exhaust waste heat of the steam turbine meets the heat load required by the user and liquefied natural gas gasification; If yes, switching the valve to deliver the waste heat of the thermal power plant to the gasifier as a gasification heat source, and simultaneously delivering the circulating water to the user side through the heat exchanger after the circulating water passes through the heat pump unit; If not satisfied, the valve opening is dynamically adjusted, and heat is preferentially supplied to the gasifier, and the seawater heat pump is started to extract heat from seawater to make up for the gap in heat load.

10. A control method of a seawater source heat pump system using surplus cold and heat, characterized by, The method comprises the following steps: determining whether the cold energy generated by liquefied natural gas gasification meets the cold load required by the condenser of the thermal power plant and the user; if satisfied, the cold energy generated by liquefied natural gas gasification is transported to the condenser through valve control, and then transmitted to the circulating refrigerant through the heat exchanger, and finally transported to the heat pump unit through the circulating refrigerant to provide refrigeration services for the user side; if not satisfied, the valve opening is dynamically adjusted, and cold is preferentially supplied to the condenser of the thermal power plant, and the low-temperature seawater is pumped and supplied to the circulating refrigerant to meet the refrigeration demand of the user side.

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