Gas power generation and heat supply equipment and control method thereof

Abstract

The invention relates to the field of power supply and heat supply, and provides gas power generation and heat supply equipment and a control method thereof.The gas power generation and heat supply equipment comprises a gas generator set, a first water pipe, a heat exchanger and a second water pipe which are sequentially connected to form a first loop, and the first loop circulates cylinder sleeve water of the gas generator set; the electric heater, the third water pipe, the heat exchanger and the fourth water pipe are sequentially connected to form a second loop, and the second loop circulates resident heating water. The absolute value of the length difference between the third water pipe and the fourth water pipe is smaller than 10% of the length of the third water pipe; when the water temperature of the electric heater is smaller than a second preset threshold value, the electric heater is used for heating the heating water; and the electric power of the electric heater is provided by the gas generator set. According to the scheme, the heat supply efficiency can be improved.

Description

Technical Field

[0001] The present invention relates to the field of power supply and heating, and in particular to a gas-fired power generation and heating device and a control method thereof. Background Art

[0002] The gas-fired power generation and heating system utilizes the waste heat generated during the gas-fired power generation process and uses it for heating, thereby improving the efficiency of energy utilization. Traditional gas-fired power plants can usually only convert part of the heat energy into electricity, while the combined heating system utilizes the remaining heat energy, reducing energy waste. By making full use of the energy of gas, the gas-fired power generation and heating system can reduce the negative impact on the environment. Compared with traditional decentralized heating methods, the combined heating system can usually reduce the emission of combustion emissions and reduce environmental pollution.

[0003] However, the existing gas-fired power generation and heating system still has problems. In small towns, factories and other scenarios, electricity consumption peaks during the day, gas-fired power generation has high output power, and waste heat is sufficient to maintain normal heating. But at night, residents' electricity consumption decreases, gas-fired power generation has low output power, and waste heat is insufficient. At the same time, the ambient temperature is low at night, and the heat loss of circulating hot water is large, which further leads to poor heating effect. In the prior art, standby boilers are usually used to provide additional heating capacity when waste heat is insufficient. However, standby boilers are expensive, have poor compatibility with waste heat heating systems, are prone to failure, and have high maintenance costs. Summary of the invention

[0004] In order to solve the problems in the prior art, the present invention provides a gas-fired power generation and heating device and a control method thereof.

[0005] In one aspect of the present invention, a gas-fired power generation and heating equipment is provided, comprising a gas-fired power generation and heating equipment, a heat exchanger, an electric heater, a first water pipe, a second water pipe, a third water pipe, and a fourth water pipe; the gas-fired power generation and heating equipment, the first water pipe, the heat exchanger, and the second water pipe are sequentially connected to form a first loop, and the first loop circulates the cylinder jacket water of the gas-fired power generation equipment; the electric heater, the third water pipe, the heat exchanger, and the fourth water pipe are sequentially connected to form a second loop, and the second loop circulates heating water for residents; the absolute value of the difference in length between the third water pipe and the fourth water pipe is less than 10% of the length of the third water pipe; when the water temperature at the electric heater is less than a second preset threshold value, the electric heater is used to heat the heating water; the power of the electric heater is provided by the gas-fired power generation equipment.

[0006] Furthermore, the gas-fired generator set includes an automated control system for monitoring and controlling the operation of the equipment.

[0007] Furthermore, the heat exchanger is used to recover waste heat during the power generation process and transfer the waste heat to heating water.

[0008] The present invention also provides a control method for gas-fired power generation and heating equipment, comprising: Obtain the historical jacket water outlet water temperature and the output power of the gas generator set, and fit them into the first function ,in is the outlet temperature of the jacket water, Output power for gas generator set, is the first function; Obtain the historical jacket water outlet temperature, ambient temperature, and water temperature at the electric heater when the electric heater is not working, and fit them into the second function ,in is the ambient temperature, is the water temperature at the electric heater, is the second function; Obtain the historical water temperature at the electric heater, the working power of the electric heater, and the water temperature after the electric heater is heated when the electric heater is working, and fit them into a third function ,in The water temperature after being heated by the electric heater, is the water temperature at the electric heater, is the working power of the electric heater, is the third function; When the water temperature at the electric heater is not less than the preset value When the electric heater does not work, the output power of the gas generator set is ,in To meet the electricity needs of residents, For power transmission efficiency; When the water temperature at the electric heater is lower than the preset value When the electric heater is started, according to the first, second and third functions, it can be known that , At this time, the electricity used is for electric heaters and residents, so: , thereby , Solving the equation, we get the power of the electric heater as ; At the same time, the output power of the gas generator set is controlled to .

[0009] Furthermore, before fitting the first function, the second function, and the third function, historical data is collected, recorded, and stored, and the collected data is preprocessed.

[0010] Further, a logarithmic curve model is used to fit the first function.

[0011] Furthermore, a linear surface is used to fit the second function.

[0012] Furthermore, a linear surface is used to fit the third function.

[0013] Furthermore, the power transmission efficiency is 0.9.

[0014] Furthermore, the residential electricity demand is preset using an ARIMA or seasonal ARIMA model.

[0015] The present invention can produce the following beneficial effects through the above technical solution: The present invention directly uses the electricity provided by the gas generator set to ensure the output power of the gas generator set when the waste heat is insufficient, and the comprehensive cost is lower than that of using an external power supply or using other boilers. In addition, when the electricity provided by the gas generator set is used in this embodiment, it can be directly obtained through the residential power grid, without the need to lay additional lines, and the cost is lower.

[0016] The present invention can also accurately calculate the power of the electric heater and the output power of the gas generator set when the demand is met, so as to use the most economical power combination under the premise of ensuring electricity and heating for residents. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a system diagram of the present invention. DETAILED DESCRIPTION

[0019] Below, the invention is preferably described in conjunction with the accompanying drawings and specific implementation methods.

[0020] This embodiment solves the above problem through the following steps: In one embodiment, reference Figure 1 The present invention provides a gas-fired power generation and heating device.

[0021] like Figure 1 As shown, the gas-fired power generation and heating equipment includes a gas-fired power generation unit, a heat exchanger, an electric heater, a first water pipe, a second water pipe, a third water pipe, and a fourth water pipe.

[0022] A gas generator set is a device that generates electricity by burning gas, including a gas engine or a gas turbine. The gas engine or gas turbine generates high-temperature and high-pressure gas by burning gas, and then uses the energy of these gases to drive the generator to generate electricity. Gas engines or gas turbines generate a lot of heat during operation, so a cooling system is required to dissipate heat to keep the operating temperature of the equipment within a safe range. The cooling system injects cooling water into the gas engine or gas turbine to take away the heat in the unit. The cooling water circulates between the unit and the outside world, which can be called cylinder jacket water.

[0023] The gas generator set is also equipped with an automatic control system for monitoring and controlling the operation of the equipment. The control system can realize automatic adjustment of gas supply, generator output, cooling system and lubrication system, etc., to ensure the safe, stable and efficient operation of the equipment. In subsequent embodiments of the present invention, the automatic control system will be improved to improve the efficiency of the entire system.

[0024] The heat exchanger is used to recover waste heat during the power generation process and transfer it to heating water. In this embodiment, a cooling water heat exchanger is used. The cooling water heat exchanger is installed in the cooling system of the gas generator set to transfer the waste heat in the engine or turbine cooling water (cylinder jacket water) to hot water or steam. This type of heat exchanger achieves heat transfer by contacting cooling water with a medium (such as water or steam).

[0025] The electric heater is a device that uses electric energy to heat a resistance wire or other electric heating element to generate heat energy. In this embodiment, the electric heater is usually used as a backup heating device to provide additional heating capacity through electric heating when the residual heat is insufficient.

[0026] The first water pipe, the second water pipe, the third water pipe and the fourth water pipe are all conventional hot water pipes, but it should be noted that the first water pipe, the second water pipe, the third water pipe and the fourth water pipe do not refer to only a section or a complete water pipe. The first water pipe, the second water pipe, the third water pipe and the fourth water pipe can all be composed of multiple sub-pipes and can include forks, as long as the different components of the system are connected.

[0027] Refer to Figure 1 The gas generator set, the first water pipe, the heat exchanger, and the second water pipe are sequentially connected to form a first loop, and the first loop circulates the jacket water of the gas generator set.

[0028] The first water pipe is a pipe for conveying hot water, the heat exchanger is used to transfer the waste heat of the gas generator set to provide heating water, and the second water pipe is a pipe for conveying cold water from the heat exchanger back to the gas generator set for use. Such a circulation system can keep the jacket water of the gas generator set circulating within a suitable temperature range to stabilize the operating temperature of the generator set and use the waste heat to provide hot water.

[0029] Refer to Figure 1 The electric heater, the third water pipe, the heat exchanger, and the fourth water pipe are sequentially connected to form a second loop, and the second loop circulates heating water for residents.

[0030] The third and fourth water pipes circulate hot water heated by the waste heat generated by the generator set to the residential heating system. The electric heater is used to heat water when the heating water temperature is insufficient to ensure the heating water temperature.

[0031] Furthermore, in this embodiment, the electric heater should be set at the central position of the entire residential system to ensure good heat relay. Specifically, in this embodiment, the absolute value of the length difference between the third water pipe and the fourth water pipe is less than 10% of the length of the third water pipe. For example, in a heating system of a small community, the total heating water pipe is about 10MK long, then the length of the third water pipe can be determined to be 4.8km, and the length of the fourth water pipe is set to 5.2km. The specific location can be determined according to the environmental location during implementation, and it can be ensured to be approximately in the center at a low cost in advance.

[0032] In order to be able to relay heat the heating water, the water temperature at the electric heater (that is, the water temperature in the middle section of the heating system) is collected to monitor the change of water temperature in the heating system. This can be achieved by installing a temperature sensor or a temperature probe on the water pipe at the electric heater. When the water temperature at the electric heater is less than the first preset threshold, it means that the interrupted water temperature is too low, and the waste heat alone is not enough to support the heating. Therefore, the electric heater is used to heat the heating water to ensure heating for residents. The electric heater has a simple structure and can directly couple the insulated electric heating wire to the raw water pipe system. Compared with the traditional boiler heating system, it is simpler, less expensive, and easier to maintain.

[0033] Furthermore, in this embodiment, the power of the electric heater is provided by the gas generator set. When the waste heat is insufficient, it is due to the reduction of electricity consumption by residents (such as the reduction of electricity consumption late at night). At this time, the output power of the gas generator set needs to be reduced, but the reduction of the output power of the gas generator set will lead to a decrease in work efficiency, which does not necessarily save gas. Therefore, in this embodiment, the direct use of the electricity provided by the gas generator set can ensure the output power of the gas generator set when the waste heat is insufficient, and the comprehensive cost is lower than that of using an external power supply or using other boilers. In addition, when the electric energy provided by the gas generator set is used in this embodiment, it can be directly obtained through the residential power grid, without the need to lay additional lines, and the cost is lower.

[0034] In another embodiment of the present invention, a control method for the gas-fired power generation and heating equipment described in the above embodiment is also provided, which specifically includes: Obtain the historical jacket water outlet water temperature and the output power of the gas generator set, and fit them into the first function ,in is the outlet temperature of the jacket water, Output power for gas generator set, is the first function.

[0035] The outlet water temperature of the cylinder jacket water depends on the output power of the gas generator set, but the relationship between them is not linear. In order to determine the relationship between the outlet water temperature of the cylinder jacket water and the output power of the gas generator set, this embodiment collects the data of the outlet water temperature and output power of the cylinder jacket water of the gas generator set in history. These data may have been recorded and stored by sensors or monitoring systems. The collected data is preprocessed, including removing outliers, processing missing values, etc. to ensure the accuracy and integrity of the data. The acquired data is curve-fitted to obtain a suitable function model. Specifically, this embodiment uses a logarithmic curve model to fit the first function.

[0036] Obtain the historical jacket water outlet temperature, ambient temperature, and water temperature at the electric heater when the electric heater is not working, and fit them into the second function ,in is the ambient temperature, is the water temperature at the electric heater, is the second function.

[0037] When the electric heater is not working, only waste heat is used to provide heating water energy. In order to simplify the model, this embodiment considers the intermediate process of the heat exchanger uniformly (only the initial state is considered). The water temperature at the electric heater mainly depends on the outlet water temperature of the cylinder jacket water and the ambient temperature, among which the outlet water temperature of the cylinder jacket water provides the initial state, and the ambient temperature affects the loss in the transmission process. Therefore, the water temperature at the electric heater (the water temperature of the middle section) is used as the dependent variable, and the outlet water temperature of the cylinder jacket water and the ambient temperature are used as independent variables to fit the second function. The process of fitting the second function is similar to that of fitting the first function. It is necessary to remember, organize, and select models for historical data, and perform surface fitting on the acquired data to obtain a suitable function model. Specifically, since at normal temperatures, the initial temperature and ambient temperature only affect the linear parameters in the heat dissipation model, this embodiment uses a linear surface to fit the second function.

[0038] Obtain the historical water temperature at the electric heater, the working power of the electric heater, and the water temperature after the electric heater is heated when the electric heater is working, and fit them into a third function ,in The water temperature after being heated by the electric heater, is the water temperature at the electric heater, is the working power of the electric heater, is the third function.

[0039] When the electric heater is working, the electric energy is converted into heat energy through the electric heating wire to heat the heating water passing through the electric heater. Therefore, the water temperature after the electric heater is heated is affected by the working power of the electric heater and the water temperature at the heater. Similar to the second function, in a small range, the relationship between the water temperature after the electric heater is heated and the working power of the electric heater and the water temperature at the heater is approximately linear. Therefore, a linear surface is used to fit the third function using a method similar to fitting the second surface.

[0040] The relationship between the main parameters in the system targeted by this implementation is determined through the aforementioned steps.

[0041] When the water temperature at the electric heater is not less than the preset value When , it means that the waste heat from power generation is sufficient for heating, and the electric heater does not work. Considering the influence of transmission efficiency, the output power of the gas generator set is ,in To meet the electricity needs of residents, For the power transmission efficiency, for the small power consumption communities targeted in this implementation, due to the short transmission distance, the power transmission efficiency can reach about 90%.

[0042] Furthermore, the residential electricity demand can use the trend, periodicity and seasonality information in the time series data to predict the future electricity demand. Specifically, the ARIMA model (autoregressive integrated moving average model) or the seasonal ARIMA model can be used.

[0043] When the water temperature at the electric heater is lower than the preset value When the residual heat is insufficient to support heating, the electric heater needs to be started. According to the first, second and third functions, the second and third functions are substituted into the first function. When the water temperature after the electric heater is heated meets the preset value, When , At this time, the electricity used is for electric heaters and residents, so: , thereby , Thus, the power of the electric heater is obtained ; At the same time, the output power of the gas generator set is controlled to .

[0044] The above method can be used to accurately calculate the power of the electric heater and the output power of the gas generator set when the demand is met, so as to use the most economical power combination while ensuring the electricity and heating of residents.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

[0046] The present invention does not particularly specify the structure of some modules, which shall be subject to the contents recorded in the prior art. The prior art mentioned in the above background technology section and the specific embodiment section of the present invention can be used as part of the present invention to understand the meaning of some technical features or parameters. The scope of protection of the present invention shall be subject to the contents actually recorded in the claims.

Claims

1. A gas-fired power generation and heating device, characterized in that: The gas-fired power generation and heating equipment comprises a gas-fired power generation unit, a heat exchanger, an electric heater, a first water pipe, a second water pipe, a third water pipe, and a fourth water pipe; The gas generator set, the first water pipe, the heat exchanger, and the second water pipe are sequentially connected to form a first loop, and the first loop circulates the jacket water of the gas generator set; The electric heater, the third water pipe, the heat exchanger, and the fourth water pipe are sequentially connected to form a second loop, and the second loop circulates heating water for residents; The absolute value of the difference between the lengths of the third water pipe and the fourth water pipe is less than 10% of the length of the third water pipe; When the water temperature at the electric heater is lower than a second preset threshold, the electric heater is used to heat the heating water; The electric power of the electric heater is provided by the gas generator set.

2. The gas-fired power generation and heating equipment according to claim 1, characterized in that: The gas generator set includes an automated control system for monitoring and controlling the operation of the equipment.

3. The gas-fired power generation and heating equipment according to claim 1, characterized in that: The heat exchanger is used to recover waste heat during the power generation process and transfer the waste heat to heating water.

4. A control method, applied to the gas-fired power generation and heating equipment according to claim 1, characterized in that: Obtain the historical jacket water outlet water temperature and the output power of the gas generator set, and fit them into the first function ,in is the outlet water temperature of the cylinder jacket water, Output power for gas generator set, is the first function; Obtain the historical jacket water outlet temperature, ambient temperature, and water temperature at the electric heater when the electric heater is not working, and fit them into the second function ,in is the ambient temperature, is the water temperature at the electric heater, is the second function; Obtain the historical water temperature at the electric heater, the working power of the electric heater, and the water temperature after the electric heater is heated when the electric heater is working, and fit them into a third function ,in The water temperature after being heated by the electric heater. is the water temperature at the electric heater, is the working power of the electric heater, is the third function; When the water temperature at the electric heater is not less than the preset value When the electric heater does not work, the output power of the gas generator set is ,in To meet the electricity needs of residents, For power transmission efficiency; When the water temperature at the electric heater is lower than the preset value When the electric heater is started, according to the first, second and third functions, it can be known that ， At this time, the electricity used is for electric heaters and residents, so: ， thereby , Solving the equation, we get the power of the electric heater as ; At the same time, the output power of the gas generator set is controlled to .

5. The control method according to claim 4, characterized in that: Before fitting the first function, the second function and the third function, historical data is collected, recorded and stored, and the collected data is preprocessed.

6. The control method according to claim 4, characterized in that: A logarithmic curve model was used to fit the first function.

7. The control method according to claim 4, characterized in that: Fit the second function using a linear surface.

8. The control method according to claim 4, characterized in that: Fit the third function using a linear surface.

9. The control method according to claim 4, characterized in that: The power transmission efficiency is 0.

9.

10. The control method according to claim 4, characterized in that: The residential electricity demand is pre-set using an ARIMA or seasonal ARIMA model.

Images